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  • 101.
    Hashmi, Muhammad Baqir
    et al.
    Univ Stavanger, Dept Energy & Petr Engn, N-4036 Stavanger, Norway..
    Mansouri, Mohammad
    Univ Stavanger, Dept Energy & Petr Engn, N-4036 Stavanger, Norway.;NORCE Norwegian Res Ctr, N-4021 Stavanger, Norway..
    Fentaye, Amare Desalegn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Ahsan, Shazaib
    Univ Manitoba, Dept Mech Engn, Winnipeg, MB R3T 5V6, Canada..
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    An Artificial Neural Network-Based Fault Diagnostics Approach for Hydrogen-Fueled Micro Gas Turbines2024In: Energies, E-ISSN 1996-1073, Vol. 17, no 3, article id 719Article in journal (Refereed)
    Abstract [en]

    The utilization of hydrogen fuel in gas turbines brings significant changes to the thermophysical properties of flue gas, including higher specific heat capacities and an enhanced steam content. Therefore, hydrogen-fueled gas turbines are susceptible to health degradation in the form of steam-induced corrosion and erosion in the hot gas path. In this context, the fault diagnosis of hydrogen-fueled gas turbines becomes indispensable. To the authors' knowledge, there is a scarcity of fault diagnosis studies for retrofitted gas turbines considering hydrogen as a potential fuel. The present study, however, develops an artificial neural network (ANN)-based fault diagnosis model using the MATLAB environment. Prior to the fault detection, isolation, and identification modules, physics-based performance data of a 100 kW micro gas turbine (MGT) were synthesized using the GasTurb tool. An ANN-based classification algorithm showed a 96.2% classification accuracy for the fault detection and isolation. Moreover, the feedforward neural network-based regression algorithm showed quite good training, testing, and validation accuracies in terms of the root mean square error (RMSE). The study revealed that the presence of hydrogen-induced corrosion faults (both as a single corrosion fault or as simultaneous fouling and corrosion) led to false alarms, thereby prompting other incorrect faults during the fault detection and isolation modules. Additionally, the performance of the fault identification module for the hydrogen fuel scenario was found to be marginally lower than that of the natural gas case due to assumption of small magnitudes of faults arising from hydrogen-induced corrosion.

  • 102.
    Hawas, Allan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Kvantifiering och visualisering av mervärden vid energieffektivisering i offentlig sektor2022Report (Other academic)
    Abstract [sv]

    Denna rapport beskriver hur ett verktyg för visualisering och kvantifiering av mervärden av energieffektivisering har vidareutvecklats i projektet Energieffektivisering i offentlig sektor (EnOff).  Det utvecklade versionen av mervärdesverktyget har dels förenklats för att öka möjlighet att användas av den offentliga sektorn, dels vidareutvecklats för att möjliggöra kvantifiering och visualisering på flera vis. Verktyget ger även möjlighet till kvantifiering och visualisering av hur projektet påverkar olika globala hållbarhetsmål, både positivt och negativt. En annan fördel är att verktyget ger redskap för att undersöka hur olika globala mål kan inkluderas och visualiseras i ett energieffektiviseringsprojekt om man har som mål att jobba för att bidra till ett visst globalt mål. Kvantifieringar och visualiseringar av mervärden presenteras i diagram och tabeller. Verktyget ger både en detaljerad och generell kvantifiering av mervärden i ett procentuellt tal som kallas för Mervärdetal som kan variera mellan negativt och positivt 100%, både på lokal och nationell nivå, vilket ger en logisk kvantifiering av mervärden vid energieffektiviserings projekt. Vidare ger det utvecklade verktyget användaren möjligheten att själv bestämma värdet av olika mervärden i relation till aktuellt projekt.  

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    Kvantifiering och visualisering av mervärden vid energieffektivisering i offentlig sektor
  • 103.
    Hawas, Allan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Skvaril, Jan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Building Thermography Inspection by using a Low-Cost Visual-Thermal Drone System2021Conference paper (Refereed)
    Abstract [en]

    For decades, thermal imaging technology serves as an effective tool and is implemented in many industrial and commercial applications, including energy and building sectors. Recent trends in the field further show an increased interest in aerial thermal imaging applications that brings new opportunities toward sustainability. Unmanned aerial vehicles (UAVs) (i.e., drones) equipped with thermal cameras are currently used for building thermography inspection, which is a crucial technology to accelerate the identification of CO2 mitigation within the building sector to tackle the global goals (SDG 11 target 11.6 and SDG 7 target 7.3). This study presents an evaluation of a low-cost, visual-thermal drone system for building thermography inspection (SDG 9 target 5.5). The evaluation was limited to the thermal imaging potentials of the system. The UAV system is used to examine its capacity to detect various heat loss, including insulation defects, air/ water leakage, and validation of different suspected energy loss case studies. The examination also involves the evaluation of the cost-effectiveness of the thermal-drone system. The thermography inspection was carried out on several buildings with different sizes, types, and activities they are used for. Therefore, the detection/identification tasks for the thermal-drone system were different from an inspection to another. This study aimed to identify different limitations and advantages of using such a low-cost thermal-drone system for building thermography inspection. The technical evaluation was based on several criteria, including fly duration, stability, image quality, data flexibility, integration potentials, etc. Additionally, the cost-effectiveness and other practical aspects were considered in the evaluation. The results show a combination of both limitations and advantages of adopting such a low-cost drone system. In contrast to the supplier's description, the thermal image data are not a radiometric JPG file that significantly limits quality and opportunities. Accordingly, the thermal image gives a standard JPG file and does not provide a temperature distribution to make any post-analysis processing or post-editing presentations. This issue can be solved partially, as the live thermal images provide a temperature distribution that allows different utilizations, e.g., identifying temperature spots, which can be included in a screenshot of the drone screen controller. Furthermore, the image data's limitations do not allow 3D modelling of the building objects which is possible for the radiometric image files. The image resolution and accuracy are limited; however, short distance inspections provide good image qualities. The results reveal that the thermal drone system can detect common insulation issues such as missing insulation and clear energy loss. However, the capacity is limited in regards to high accuracy demand and more in-depth data analysis. In conclusion, the examined drone system is a cost-effective tool for DIY use and superficial aerial building thermography inspection (SDG 11 target 11.6). Therefore the suggested system is not sufficient for higher demand and more professional inspections. The suggested proposal is an effective method to identify CO2 mitigation potentials within the buildings that are significantly promoting the achievement of some SDGs. Additionally, the inspection method can be conducted remotely, keeping social distancing in the time of pandemics.

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  • 104.
    He, W.
    et al.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Zhang, J.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Liu, S.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Wang, Y.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Lv, B.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Wei, J.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Optimal Thermal Management Of Server Cooling System Based Cooling Tower Under Different Ambient Temperatures2022In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 207, article id 118176Article in journal (Refereed)
    Abstract [en]

    To develop a highly efficient and energy-saving cooling system in a data center, this study investigates the optimal thermal management both on the internal server cooling cycle and external cold source water cycle under different ambient temperatures based on the principle of minimal power consumption. Taking a server cabinet of 4.8 kW as the case, an internal indirect water-cooled heat sink cycle and an external cooling tower cold source cycle are constructed. A hybrid thermal management model combined with a heat dissipation model and a power consumption model was developed with the aid of MATLAB and TRNSYS. Using this model, the relationship between the chip dissipation performance attached to the fin-type heat sink and the energy consumption performance of the cooling system under different water working conditions and ambient temperatures was analyzed. Finally, to achieve minimal system energy consumption, the optimized inlet temperature and water flow rates corresponding to different ambient temperatures were obtained by fitting expressions that can better serve the optimal design of data center cooling systems. Furthermore, when the optimal value was applied using the year-round temperature of Tianjin, China in the case study, a 21.3% reduction in power consumption and a 4.43% decrease in the power usage effectiveness can be achieved compared to the case without optimization. Therefore, significant power can be saved in a data center cooling system through thermal management optimization. 

  • 105.
    He, Xiaohe
    et al.
    Department of Biomedical Engineering, College of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, China.
    Wu, Meng
    Department of Biomedical Engineering, College of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, China; Tianjin Guokeyigong Science & Technology Development Co., Ltd., Tianjin, China.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Liu, Shengchun
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Liu, Bin
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Qi, Hongzhi
    Department of Biomedical Engineering, College of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, China; Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.
    Real-time regulation of room temperature based on individual thermal sensation using an online brain–computer interface2022In: Indoor Air, ISSN 0905-6947, E-ISSN 1600-0668, Vol. 32, no e13106, article id e13106Article in journal (Refereed)
    Abstract [en]

    Regulation of indoor temperature based on neurophysiological and psychological signals is one of the most promising technologies for intelligent buildings. In this study, we developed a system for closed-loop control of indoor temperature based on brain-computer interface (BCI) technology for the first time. Electroencephalogram (EEG) signals were collected from subjects for two room temperature categories (cool comfortable and hot uncomfortable) and used to build a thermal-sensation discrimination model (TSDM) with an ensemble learning method. Then, an online BCI system was developed based on the TSDM. In the online room temperature control experiment, when the TSDM detected that the subjects felt hot and uncomfortable, BCI would automatically turn on the air conditioner, and when the TSDM detected that the subjects felt cool and comfortable, BCI would automatically turn off the air conditioner. The results of online experiments in a hot environment showed that a BCI could significantly improve the thermal comfort of subjects (the subjective thermal comfort score decreased from 2.45 (hot uncomfortable) to 0.55 (cool comfortable), p < 0.001). A parallel experiment further showed that if the subjects wore thicker clothes during the experiment, the BCI would turn on the air conditioner for a longer time to ensure the thermal comfort of the subjects. This has further confirmed the effectiveness of TSDM model in evaluating thermal sensation under the dynamic change of room temperature and showed the model's good robustness. This study proposed a new paradigm of human-building interaction, which is expected to play a promising role in the development of human-centered intelligent buildings.

  • 106.
    Helmryd Grosfilley, Emil
    et al.
    Uppsala University, Sweden.
    Robertson, Gustav
    Uppsala University, Sweden.
    Soibam, Jerol
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Le Corre, Jean-Marie
    Westinghouse Electric Sweden AB, Sweden.
    Investigation of Machine Learning Regression Techniques to Predict Critical Heat Flux over a Large Parameter Space2023In: Proceedings 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-20) Washington, D.C., August 20-25, 2023, 2023, p. 4516-4529Conference paper (Refereed)
    Abstract [en]

    A unifying and accurate model to predict Critical Heat Flux (CHF) over a wide range of conditions has been elusive since wall boiling research emerged. With the release of the data utilized in the development of the 2006 Groeneveld CHF lookup table (LUT), by far the most extensive public CHF database available to date (nearly 25000 data points), development of data-driven predictions models over a large parameter space in simple geometry (vertical, uniformly heated round tubes) can be performed. Furthermore, the popularization of machine learning techniques to solve regression problems has led to more advanced tools for analyzing large and complex databases. This work compares three machine learning algorithms to predict the entire LUT CHF test database. For each selected regression algorithm (ν-Support vector, Gaussian process, and neural network), an optimized hyperparameter set is fitted. The best-performing algorithm is the neural network, which can achieve a standard deviation of the predicted/measured factor of 12.3%, three times lower than the LUT. In comparison, the Gaussian process regression and the ν-Support vector regression achieve a standard deviation of 17.7%, about two times lower than the LUT. All considered algorithms hence significantly outperform the LUT prediction performance. The neural network model and training methodology are designed to prevent overfitting, which is confirmed by data analysis of the predictions. Finally, a feasibility study of transfer learning is presented and future development directions (including uncertainty quantification) are discussed. 

  • 107.
    Hennessy, Jay
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. RISE Research Institutes of Sweden.
    Avoiding greenhouse gas emissions using flexibility in smart thermal grids2023Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The Paris Agreement on climate change entered into force in 2016 and has been ratified by 193 of the 197 Parties to-date, followed by country targets to cut greenhouse gas emissions, not least through an increasing penetration of renewable energy sources. In its 2021 annual World Energy Outlook, the IEA envisages a Net-Zero Emissions by 2050 scenario (NZE) in which renewables as a percentage of total energy supply increase from around 10% in 2020 to over 65% in 2050 and is reflected by a similar change in the percentage of variable renewables in total generation, thereby increasing the need for system flexibility.

    Thermal grids are a significant supplier of heat to buildings in Europe, Russia and China, providing 45 % of heat in some European countries. One of the advantages of district heating is its ability to consume multiple fuel sources, including electricity. Technologies for converting heat back to electricity mean that, in theory, district heating can adjust both the consumption of electricity, and potentially supply electricity, to provide short-term flexibility and ancillary services to the power grid, and thus may help to meet future system flexibility needs.

    This thesis describes the results of literature reviews and a techno-economic study to determine and quantify the potential for thermal grids to address future system flexibility needs, through possible contributions to the electricity balancing market or provision of ancillary services. These studies focus on the potential use of heat-to-power technologies in thermal grids; on identifying and quantifying short term heat storage options that can be used for increased flexibility in thermal grids; and whether the use of this flexibility could contribute to reduced curtailment of renewable electricity sources, leading to avoided emissions. 

    The results show that most thermal grids have multiple options for the storage of heat, with storage capacity already available that could potentially be used to provide additional flexibility. Stored heat may be converted to electricity with commercially available heat-to-power technologies, although economic feasibility may still be limited. It is shown that if storage flexibility is used to reduce the curtailment of renewable energy sources at a country scale through power-to-heat technology, this storage flexibility can lead to megatonnes of avoided CO₂eq emissions.

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  • 108.
    Hu, C.
    et al.
    Tianjin University of Commerce, China.
    Dong, Beibei
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Tianjin University of Commerce, China.
    Liu, S.
    Tianjin University of Commerce, China.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Different control strategies for MEA based chemical absorption2021In: Energy Proceedings, Scanditale AB , 2021, Vol. 22Conference paper (Refereed)
    Abstract [en]

    When capturing CO2 from biomass fired combined heat and power plants, the dynamic changes in the feedstock and the heat and electricity demands can clearly affect the operation of the boiler, which can further affect the performance of chemical absorption CO2 capture. To handle such dynamic changes, control systems are needed. This work aims to compare the performance of two control strategies that can control the reboiler duty in the stripper to achieve a constant capture rate. Control strategy A uses the reboiler temperature as input based on a PID controller; and control strategy B is a modification of control strategy A by introducing a feedforward compensation based on the flowrate of rich solution when regulating the reboiler duty. Based on dynamic simulations, it is found that control strategy B can reduce the settling time and capture more CO2 with a lower average energy penalty within a certain time length.

  • 109.
    Hu, N.
    et al.
    Department of Civil and Architectural Engineering, KTH Royal Institute of Technology, Sweden.
    Lans, J.
    Faculty of Architecture and the Built Environment, Delft University of Technology, Netherlands. Reinier de Graaf Hospital, Delft, Netherlands.
    Gram, A.
    Department of Civil and Architectural Engineering, KTH Royal Institute of Technology, Sweden.
    Luscuere, P.
    Faculty of Architecture and the Built Environment, Delft University of Technology, Netherlands.
    Sadrizadeh, Sasan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Department of Civil and Architectural Engineering, KTH Royal Institute of Technology, Sweden.
    Ventilation performance evaluation of an operating room with temperature-controlled airflow system in contaminant control: A numerical study2024In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 259, article id 111619Article in journal (Refereed)
    Abstract [en]

    This article investigates the efficacy of temperature-controlled airflow systems in modern operating rooms for contaminant control, a critical factor in preventing surgical site infections. We have conducted experimental measurements in an operating room equipped with temperature-controlled ventilation to map the airflow field and contaminant dispersion (airborne particles with diameters ranging from 0.5 to 1 μm). The results were used to validate the computational fluid dynamics code, which was then employed to simulate and examine different conditions, including contaminant release locations and air supply rates. Realizable k-epsilon and passive scalar models were utilized to simulate airflow and airborne particle phases. We assessed the airflow distribution and contaminant dispersion, utilizing indices such as ventilation and air change efficiency scales. The analysis provided quantitative insights into the distribution and removal of contaminants, as well as the speed at which the room air was replaced. Contamination was found to be effectively reduced when contaminants were released near exhaust outlets or under central unidirectional inlets. The presence of the operating table caused a big distortion of the central downward airflow, forming a horizontal air barrier at the periphery. Under this unique interior configuration, an appropriate air supply ratio between central and periphery zones was required to achieve optimal overall ventilation performance.

  • 110.
    Hu, N.
    et al.
    Department of Civil and Architectural Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Yuan, F.
    Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing, China.
    Gram, A.
    Department of Civil and Architectural Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Yao, R.
    Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing, China; National Centre for International Research of Low-Carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing, China; School of the Built Environment, University of Reading, Reading, United Kingdom.
    Sadrizadeh, Sasan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Department of Civil and Architectural Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Review of experimental measurements on particle size distribution and airflow behaviors during human respiration2024In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 247, article id 110994Article in journal (Refereed)
    Abstract [en]

    In recent years, pandemic outbreaks have raised concerns about the spread of respiratory infections and their impact on public health. Since the pathogen emission during human respiration is recognized as the primary source, characterizing the physical properties of exhaled particles and airflow has become a crucial focus of attention. This article critically reviews experimental studies in exhaled particles and airflow, examines the uncertainty introduced by different measurement methods, analyzes how it is reflected in measurement outcomes, and provides an in-depth understanding of particle size distribution and airflow behaviors of human respiration. The measurement techniques assessment highlights the variability among particle sizing techniques in detection size range, collection efficiency, hydration status of captured particles, and experimental protocols. A combination of sampling-based instruments and laser imaging systems is recommended for particle sizing to cover a wider detection range, with refined setups in thermal conditions, sampling distance, volume, and duration. Meanwhile, it identifies the complementary nature of qualitative and quantitative measurements of airflow characterization techniques. Image recording systems plus data reconstruction programs are suggested to capture dynamic airflow features while accuracy validation by other techniques is required at the same time. Subsequent analysis of the measurement data showed that the various experimental measurements provided substantial information, but they also revealed disagreements and challenges in quantification. The dominance of submicron aerosols in exhaled particles and jet-like transport in exhaled airflow is obvious. More efforts should be made to measure particles larger than 20 μm, capture airflow dynamics in a high temporal and spatial resolution, and quantify the impact of face coverings to improve the understanding of human respiratory emissions.

  • 111.
    Huang, Q.
    et al.
    Institute for Advanced Technology, Shandong University, Jinan, 250061, China.
    Feng, B.
    PowerChina HuaDong Engineering Corporation Limited, Hangzhou, 311122, China.
    Liu, S.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, 300134, China.
    Ma, C.
    Institute for Advanced Technology, Shandong University, Jinan, 250061, China.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Sun, Q.
    Institute for Advanced Technology, Shandong University, Jinan, 250061, China.
    Dynamic operating characteristics of a compressed CO2 energy storage system2023In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 341, article id 120985Article in journal (Refereed)
    Abstract [en]

    For the first time, the study investigated the dynamic performances of a compressed CO2 energy storage (CCES) system based on a dynamic model, which was validated using experimental data. The dynamic round-trip efficiency (RTE) of a scaled-up CCES system in two typical operation modes was studied, including Mode 1: the basic operation mode, where the inlet pressure of the compressor or the expander is not controlled, and Mode 2: the controlled operation mode, where the capacity for compression or expansion is regulated to remain constant. Dynamic RTE varies in the range 16.7%-56.7% in various operation modes. A new key performance indicator, utilization of tank (UOT), was defined to reflect how much working gas is used in a charging or a discharging process. In general, high charging and high discharging capacities lead to low UOTs and low RTEs. Moreover, the comparison between the dynamic model and its equivalent steady-state model showed a significant difference in system performances. The RTE of the steady-state model reaches 68.5%, which is much higher than the corresponding dynamic RTE of 55.3%. © 2023

  • 112.
    Huang, Qingxi
    et al.
    Shandong Univ, Inst Adv Technol, Jinan 250061, Peoples R China..
    Yao, Jinduo
    Tianjin Univ Commerce, Sch Mech Engn, Tianjin Key Lab Refrigerat Technol, Tianjin, Peoples R China..
    Hu, Yukun
    UCL, Dept Civil Environm & Geomat Engn, London WC1E 6BT, England..
    Liu, Shengchun
    Tianjin Univ Commerce, Sch Mech Engn, Tianjin Key Lab Refrigerat Technol, Tianjin, Peoples R China..
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Tianjin Univ Commerce, Sch Mech Engn, Tianjin Key Lab Refrigerat Technol, Tianjin, Peoples R China..
    Sun, Qie
    Shandong Univ, Inst Adv Technol, Jinan 250061, Peoples R China.;Shandong Univ, Inst Thermal Sci & Technol, Jinan 250061, Peoples R China..
    Integrating compressed CO(2 )energy storage in an oxy-coal combustion power plant with CO2 capture2022In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 254, article id 124493Article in journal (Refereed)
    Abstract [en]

    To compensate for the high cost of CO2 capture, this study proposes a novel solution that integrates a compressed CO2 energy storage (CCES) system into an oxy-coal combustion power plant with CO2 capture (Oxy_CCES). The integration of energy storage has the potential to create arbitrage from variations in electricity prices. The proposed Oxy_CCES system can achieve a higher net efficiency of 34.1%, and a higher exergy efficiency of 57.5%, than that of a liquified oxygen storage-integrated oxy-coal combustion power plant (Oxy_O-2). Two scenarios, i.e., retrofitting an existing oxy-coal combustion power plant (S-I) and building a new plant (S-II), were established to compare the Oxy_CCES and Oxy_O-2. In S-I, the payback time of the Oxy_CCES is one year and in the S-II the levelized cost of electricity (LCOE) of the Oxy_CCES increases by 1.8%, which is lower than that of the Oxy_O-2. The sensitivity analysis shows that, when the difference between the peak and the valley electricity prices and the capacities of the energy storage systems increase by 50%, the net present value (NPV) and LCOE of the Oxy_CCES system increase by 113.4% and 1.7% respectively, which are lower than the NPV and LCOE increase of the Oxy_O-2.

  • 113.
    Huang, X.
    et al.
    Institute of Building Environment and Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Chin.
    Li, F.
    Institute of Building Environment and Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Chin.
    Liu, Z.
    Institute of Building Environment and Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Chin.
    Gao, X.
    Institute of Building Environment and Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Chin.
    Yang, X.
    Institute of Building Environment and Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Chin.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Department of Building Environment and Energy Engineering, Hong Kong Polytechnic University, Kowloon, Hong Kong.
    Design and optimization of a novel phase change photovoltaic thermal utilization structure for building envelope2023In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 218, article id 119269Article in journal (Refereed)
    Abstract [en]

    The building envelope is of great significance for building thermal comfort, and photovoltaic heat (PV/T) can be effectively utilized through phase change heat storage technology to reduce heating energy consumption. In this paper, a phase change heat storage structure with subzone rotation is proposed for the building envelope. A numerical model of a triplex-tube LHTES unit is established by using the enthalpy-porosity method and verified by experimental data. The study employs the Taguchi method to select rotation speed in different regions and fin/tube wall material as variables. The effects of different variables on heat release rate and solidification time are investigated, and the interaction of each parameter on solidification performance is analyzed through signal-to-noise ratio. The findings indicate that when the inner and outer tube speeds are 0.3 rpm and 0.5 rpm, respectively, compared to the initial model where both inner and outer tube speeds are 0.1 rpm, the average temperature response rate and the average heat release rate are increased by 51.47% and 61.04%, respectively. Meanwhile, the solidification time is shortened by 40.49%. However, the release of the total heat is reduced by 0.66%. The study concludes that increasing rotation speed or solidification consistency of PCM in different areas is of great value in enhancing overall solidification performance. Finally, the specific effect of increasing regional rotation speed on the solidification process is studied through temperature/flow rate monitoring in the unit.

  • 114.
    Huang, X.
    et al.
    Institute of the Building Environment & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
    Li, F.
    Institute of the Building Environment & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
    Lu, L.
    Institute of the Building Environment & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
    Li, Z.
    Institute of the Building Environment & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
    Yang, X.
    Institute of the Building Environment & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Renewable Energy Research Group (RERG), Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong.
    Depth optimization of solidification properties of a latent heat energy storage unit under constant rotation mechanism2023In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 290, article id 113099Article in journal (Refereed)
    Abstract [en]

    Latent heat storage technology plays an important role in the effective utilization of clean energy such as solar energy in building heating, but the low thermal conductivity of heat storage medium (phase change material) affects its large-scale application. As a new heat storage enhancement technology, rotation mechanism has a good application prospect. In this paper, the solidification performance of a triplex-tube latent heat thermal energy storage unit at constant speed (0.5 rpm) is studied numerically. Different optimization design methods (Taguchi method and response surface method) are used for deep analysis. The influences of fin position, number, and material on solidification properties are explored by the Taguchi method. Then, the unit structure (fin angle, fin length, and fin width) is optimized by the response surface method. Compared with the original structure, the average heat release rate of 8 copper fins with all outer tubes is increased by 108.93%, and the solidification time is reduced by 52.06%. The optimal structure can further shorten the solidification time by 29.14% and increase the average heat release rate by 40.5%. Additionally, the study of wall temperature shows that increasing temperature difference makes solidification speed faster and heat energy release faster. This effect effectively eliminates the adverse effects of slow solidification during the later stages of the process on the system. 

  • 115.
    Huang, X.
    et al.
    Institute of the Building Environment & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China.
    Zhou, R.
    State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, China.
    Luo, X.
    Institute of the Building Environment & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China.
    Yang, X.
    Institute of the Building Environment & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China.
    Cheng, J.
    Institute of the Building Environment & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Experimental research and multi-physical modeling progress of Zinc-Nickel single flow battery: A critical review2023In: Advances in Applied Energy, ISSN 2666-7924, Vol. 12, article id 100154Article in journal (Refereed)
    Abstract [en]

    Electrochemical energy storage technologies hold great significance in the progression of renewable energy. Within this specific field, flow batteries have emerged as a crucial component, with Zinc–Nickel single flow batteries attracting attention due to their cost-effectiveness, safety, stability, and high energy density. This comprehensive review aims to thoroughly evaluate the key concerns and obstacles associated with this type of battery, including polarization loss, hydrogen evolution reaction, and dendrite growth, among others. Additionally, the study highlights ongoing research endeavors focused on addressing these concerns, such as optimizing battery operating conditions and developing new electrodes. Furthermore, recent advancements in experimental processes and multi-scale numerical simulations of Zinc–Nickel single flow batteries, facilitated by the visual literature analysis software VOSviewer, are also explored. The primary objective of this review is to acquire a comprehensive understanding of the electrochemical reaction and internal mass transfer mechanism of Zinc–Nickel single flow batteries, while also anticipating future research directions and prospects.

  • 116.
    Hui, H.
    et al.
    College of Electrical Engineering, Zhejiang University, Hangzhou, 310027, China.
    Bao, M.
    College of Electrical Engineering, Zhejiang University, Hangzhou, 310027, China.
    Ding, Y.
    College of Electrical Engineering, Zhejiang University, Hangzhou, 310027, China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, 999077, Hong Kong.
    Song, Y.
    State Key Laboratory of Internet of Things for Smart City, University of Macau, Macau, 999078, China.
    Probabilistic integrated flexible regions of multi-energy industrial parks: Conceptualization and characterization2023In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 349, article id 121521Article in journal (Refereed)
    Abstract [en]

    Multi-energy industrial parks, composed of the district energy supply system and terminal industrial loads, are dominant energy consumers with over 50% occupation of total energy consumption. Considering the energy conversion in the district energy supply system and adjustment of production subtasks in terminal industrial loads, the industrial parks could provide considerable flexibility for utility multi-energy systems to deal with contingencies. However, industrial parks may have multiple uncertainties originating from the production subtasks' variability, distributed renewable energy's fluctuation, and random failures of equipment. These uncertainties could make the flexibility assessment of industrial parks unreliable, which may further exacerbate utility system risks. To address the problem, this paper innovatively proposes the concept of probabilistic integrated flexible regions and corresponding characterization approaches, which can effectively describe the credible multi-energy adjustment ability of industrial parks. First, the energy-material flows in the industrial park are modeled considering multiple uncertainties while subject to constraints such as operating limits of equipment, energy and material balancing, and production targets. Then, the modeling and calculation methods of probabilistic integrated flexible regions are given. These regions are labeled with certain probability requirements and visualized in the input multi-energy space. Using a real-world test system that produces air conditioning equipment in China, the results show that the proposed model can effectively reflect the probability characteristics of the integrated flexibility under multiple uncertainties. For this test system, the area of a highly credible integrated flexibility, represented by the probabilistic integrated flexible region with 99% probability, is about half of that obtained by the deterministic model. That is, half of the integrated flexibility evaluated by the deterministic method in the test system may not be practically utilized considering the impacts of uncertainties. Therefore, the proposed method could provide a credible and comprehensive evaluation of the multi-energy industrial park's flexibility considering multiple uncertainties. 

  • 117.
    Huo, Yanda
    et al.
    School of Electrical Engineering & Automation, Tianjin University, Tianjin, China.
    Li, Peng
    School of Electrical and Information Engineering, Tianjin University, Tianjin, Tianjin, China.
    Ji, Haoran
    School of Electrical Engineering&Automation, Tianjin University, Tianjin, China.
    Yu, Hao
    School of Electrical and Information Engineering, Tianjin University, Tianjin, China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wu, Jianzhong
    School of Engineering, Cardiff University, Cardiff, United Kingdom of Great Britain and Northern Ireland.
    Wang, Chengshan
    School of eleltrical engineering and automation, Tianjin University, Tianjin, China.
    Data-driven Coordinated Voltage Control Method of Distribution Networks with High DG Penetration2023In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 38, no 2, p. 1543-1557Article in journal (Refereed)
    Abstract [en]

    The highly penetrated distributed generators (DGs) aggravate the voltage violations in active distribution networks (ADNs). The coordination of various regulation devices such as on-load tap changers (OLTCs) and DG inverters can effectively address the voltage issues. Considering the problems of inaccurate network parameters and rapid DG fluctuation in practical operation, multi-source data can be utilized to establish the data-driven control model. In this paper, a data-driven coordinated voltage control method with the coordination of OLTC and DG inverters on multiple time-scales is proposed without relying on the accurate physical model. First, based on the multi-source data, a data-driven voltage control model is established. Multiple regulation devices such as OLTC and DG are coordinated on multiple time-scales to maintain voltages within the desired range. Then, a critical measurement selection method is proposed to guarantee the voltage control performance under the partial measurements in practical ADNs. Finally, the proposed method is validated on the modified IEEE 33-node and IEEE 123-node test cases. Case studies illustrate the effectiveness of the proposed method, as well as the adaptability to DG uncertainties.

  • 118.
    Iplik, Esin
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Linde GmbH.
    Energy savings for petroleum processing: Using mathematical models, optimal control and diagnostics2023Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Petroleum products are widely used as an energy supply, and the total production capacity of petroleum refineries is quite high. In this thesis, an energy intensive refinery process, hydroprocessing, is selected and evaluated in terms of its energy loss contributors. Digital solutions are discussed and demonstrated to reduce losses. Both hydrotreatment and hydrocracking processes are included in the evaluation since both require elevated temperatures due to the relevant reactions. While the former is the removal of undesired atoms, the latter is the production of short chain hydrocarbons from heavy oil. Both these processes contribute to cleaner fuel production.

    When these processes are carried out in fixed bed reactors, the catalyst ages over time, slowing the reactions. Understanding the changes in system dynamics enables the control system to calculate the necessary temperature adjustments to facilitate stable product quality. The usual response is increasing the temperature, which adds to the heat load. If reaction rates are known, the temperature increase can be kept to a minimum. Obtaining real-time feed quality information can aid flexible feed processing refineries intensely. With real-time feed characterization, it is possible to use a feed forward model predictive control system to optimize reactor temperatures. Therefore, for varying crude oil quality, the control system can estimate the minimum temperature requirements for the product to be in the desired quality interval. Additional notice should be given to the temperature sensors as they supply data to the suggested control architecture. Wrong measurements threaten the optimality of the estimated control response. Faulty sensors should be detected and replaced to minimize the risk and collect correct data.

    Observations made in this thesis show the possible energy gain for hydroprocessing by understanding the aging catalyst, soft sensor installation, feed forward model predictive control, and sensor fault detection. Hydroprocessing is a relevant topic for biorefineries. Although the demonstrations in this work are only for petroleum refineries, the suggested methods can be used in biorefineries as well as integrated co-processing petroleum and biorefineries.

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  • 119.
    Iplik, Esin
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Metals, Combustion and Energy, Linde Technology, 85716 Unterschleißheim, Germany.
    Aslanidou, Ioanna
    Mälardalen University, School of Innovation, Design and Engineering, Innovation and Product Realisation.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    A Feedforward Model Predictive Controller for Optimal Hydrocracker Operation2022In: Processes, E-ISSN 2227-9717, Vol. 10, no 12, p. 2583-2583Article in journal (Refereed)
    Abstract [en]

    Hydrocracking is an energy-intensive process, and its control system aims at stable product specifications. When the main product is diesel, the quality measure is usually 95% of the true boiling point. Constant diesel quality is hard to achieve when the feed characteristics vary and feedback control has a long response time. This work suggests a feedforward model predictive control structure for an industrial hydrocracker. A state-space model, an autoregressive exogenous model, a support vector machine regression model, and a deep neural network model are tested in this structure. The resulting reactor temperature decisions and final diesel product quality values are compared against each other and against the actual measurements. The results show the importance of the feed character measurements. Significant improvements are shown in terms of product quality as well as energy savings through decreasing the heat duty of the preheating furnace. 

  • 120.
    Iplik, Esin
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Warsinski, Johannes
    Enercon - WRD GmbH, Germany.
    Aslanidou, Ioanna
    Mälardalen University, School of Innovation, Design and Engineering, Innovation and Product Realisation.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Feasibility study on the use of electrolyzers for short term energystorage2021In: The First SIMS EUROSIM Conference on Modelling and Simulation, SIMS EUROSIM 2021, and 62nd International Conference of Scandinavian Simulation Society: Proceedings / [ed] Esko Juuso; Bernt Lie; Erik Dahlquist; Jari Ruuska, 2021, p. 234-240Conference paper (Refereed)
    Abstract [en]

    Electricity grid flexibility is vital for renewable energy to be used effectively. Power-to-gas technologies are investigated to connect electricity grid to gas grid and to tackle capacity challenges. Grid management expenses consist of redispatch and feed-in management. These management procedures, next to being costly, cause a significantenergy loss. Proton-exchange membrane electrolyzer installations were studied to reduce these expenses and recover energy. The change in the levelized cost of hydrogen production with varying electrolyzer capacities was presented. The sensitivity of the levelized cost and net presentvalue with respect to installation costs, maintenance costs, and electricity prices were investigated. While the electricity prices have the most significant effect on the levelized cost of hydrogen production, the net present value was affected considerably by the hydrogen selling price. Possible energy savings were calculated between 2 – 23 GWh for 2, 5, 10, 20 MW installations. The annual gridmanagement expense savings were in the range of 0.2– 2.3 million Euros, increasing with the increasing electrolyzer capacity.

  • 121.
    Ivan, Heidi Lynn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Fault Detection in Wastewater Treatment: Process Supervision to Improve Wastewater Reuse2023Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    As wastewater treatment plants transition to water resource recovery facilities, the need for improved control and consequently supervision increases. Despite the large volume of research that has been performed on this topic, the use in industry is scarce. Practical implementation is challenging due to the nature of the process, and a lack of standardisation in the research results in uncertainty as to the state of the art. This is one of the main challenges identified. 

    Experimental work is performed using the Benchmark Simulation Model No. 1 to identify monitoring requirements and evaluate the performance of univariate fault detection methods. For the former, residual based process fault signatures are used to determine minimal sensor requirements based on detectability and isolability goals. Sensor faults are the focus of the latter issue, using the Shewhart, cumulative sum, and exponentially weighted moving average control charts to detect bias and drift faults in a controlled variable sensor. 

    The use of a standard model and known fault detection methods is useful to establish a baseline for future work. Given the lack of standardised use in industry this is considered critical. Both proposed methods emphasise ease of visualisation which is beneficial for industrial implementation. 

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  • 122.
    Izadi, T.
    et al.
    School of Mechanical Engineering, Shiraz University, Iran; Department of Mechanical Engineering, Shahid Bahonar University of Kerman, Iran.
    Mehrabian, M. A.
    Department of Mechanical Engineering, Shahid Bahonar University of Kerman, Iran.
    Sadrizadeh, Sasan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. KTH Royal Institute of Technology, Stockholm, Sweden.
    Olofsson, U.
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Abouali, O.
    School of Mechanical Engineering, Shiraz University, Iran; KTH Royal Institute of Technology, Stockholm, Sweden.
    The effect of ventilation system with and without under-platform exhaust on the concentration of braking micro-particles inside the subway system2022In: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 128, article id 104638Article in journal (Refereed)
    Abstract [en]

    Thermal comfort has been the main target of the ventilation in subway systems. However, pollutant concentration and aerosol dispersion could be the leading health issues in underground metro stations. This study numerically simulated a train movement inside a subway system using the Dynamic Mesh Technique for a 3-D computational domain consisting of four stations and connecting tunnels. The effects of both the ventilation system and the train-induced fluid flow inside the subway system were investigated. Then, the particle generation and dispersion due to train braking are considered, and the impact of the ventilation system on reducing the particle concentration inside the station was investigated. It is shown that the airflow inside the subway system is entirely affected by the piston effect. The airflow generated by the train movement is much higher than that generated by the operation of the ventilation system when only one train passes through the tunnel. The results show that the ventilation system, consisting of the supply and exhaust fans inside the tunnel and supply grilles inside the platform, can reduce the particle concentration by half, except for the platform beside the stopped train when the train enters the station and during half of the train stop time. The other design concept demonstrates that the under-platform exhaust system considerably reduces the concentration of the particles released by the train braking system on the trackside platform.

  • 123.
    Jalilzadehazhari, Elaheh
    et al.
    Linneaus University, Sweden.
    Vadiee, Amir
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Johansson, J.
    Linneaus University, Sweden.
    Subsidies required for installing renewable energy supply systems considering variations in future climate conditions2021In: Journal of Building Engineering, E-ISSN 2352-7102, Vol. 35, p. 101999-101999, article id 101999Article in journal (Refereed)
    Abstract [en]

    Improving the energy performance of detached houses is expected to play an important role in achieving energy and climate targets in Sweden. The majority of detached houses require energy renovations due to technical deteriorations in heating, ventilation, and air conditioning systems approaching the ends of their lives. Renewable energy supply system implementation leads to total energy use reduction. No previous studies provided information regarding how possible climate futures could affect subsidies required to implement these systems. This study compared the performance of an air-to-water heat pump (ASHP), a ground-source heat pump (GSHP), and an integrated system of a ground-source heat pump and photovoltaic solar panels (GSHP-PV) in reducing the total energy use of a detached house, which was initially supplied by an electric boiler. The performances of the supply systems were analysed in regard to three different climate scenarios, following the Special Report of Emissions Scenarios, A2 storyline. The effects of three different interest rates and two different lifetimes on subsidies were also investigated for all three energy supply systems. The GSHP-PV system was the most efficient system, as it secured 97%–100% of the total energy consumption, followed by GSHP and AWHP. The analyses of the results showed that variations in future climate conditions changed the subsidies required to install the supply systems. Furthermore, the results showed that changes in lifetime had greater impact on subsidies than interest rate growth.

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  • 124.
    Jani, Yahya
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Malmö University, Malmö, Sweden.
    Adsorption: A Cost-Effective Wastewater Treatment Technology for Removal of Conventional and Emerging Organic Contaminants2022In: The Handbook of Environmental Chemistry, Berlin, Heidelberg: Springer, 2022Chapter in book (Refereed)
    Abstract [en]

    Water is a vital component for sustaining life on the earth because it is interacted with all metabolic activities of all living beings (human, plants, and others). The decomposition of organic pollutants, in general, causes oxygen deficiency in water bodies that can lead to severe damages in the ecosystem. Therefore, cost-effective innovative methods for the purification of wastewater is always needed. One of the most important methods that has gathered attention is adsorption. This method has witnessed continuous development in the case of the selected materials as adsorbents. Low cost as well as the production of new nano-materials have been used for the decontamination of water. In this chapter, a general overview based on the information available in the literature was produced to highlight the importance of adsorption as a method for the purification of water from conventional and emerging organic compounds.

  • 125.
    Jani, Yahya
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Waste generation and future consumption challenges2022In: Book of abstracs: Linnaeus ECO-TECH '22, Kalmar/Sweden, 2022Conference paper (Refereed)
    Abstract [en]

    Human consumption of the earth natural resources has reach to a top level where the Earth can no longer be able to regenerate these resources again. Freshwater, food, metals and many other natural materials are already suffering from a real reduction in their primary sources due to the uncontrol consumption of modern civilization. On the other hand, this consumption of materials is directly connected to the generation of different forms of waste streams that adding extra challenges to our environment and human life like climate change, water contamination and air pollution. Many landfills and dumpsites are already filled with wastes and there is no space for more wastes and therefore there is a need to find innovative methods to deal with landfilled or dumped wastes. In this talk, Dr. Yahya Jani will focus on why there is a need to extract waste materials from landfills and how mining materials from landfills can be used as secondary resources and how landfills and dumpsites can act as bank accounts for human future needs of natural materials.

  • 126.
    Jani, Yahya
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Linnéuniversitetet, Institutionen för biologi och miljö (BOM), Sweden.
    Hogland, William
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Reduction-melting extraction of trace elements from hazardous waste glass from an old glasswork’s dump in the southeastern part of Sweden2017In: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 24, no 34, p. 26341-26349Article in journal (Refereed)
    Abstract [en]

    At the southeastern part of Sweden, old art and crystal waste glass has been identified as a hazardous waste due to high weight concentrations of Pb (32.398%), Cd (0.085%) and As (1.976%). The reduction-melting technique was used to investigate the extraction of these trace elements from powder waste glass of particle size <1 mm. Following a factorial design technique, the experimental results of the reduction-melting method showed that 99.9% of Pb, 100% of Cd and 99% of As could be extracted. For a batch of 10 g powder waste glass, the found experimental and theoretical optimum operating conditions were 1100 oC of melting temperature, 5 g of Na2CO3, 2 g of carbon and 120 min of melting time. The reduction-melting method displayed promising results which might help in recycling the extracted trace elements and glass compared to the current used solution of landfilling as hazardous wastes. 

  • 127.
    Jani, Yahya
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Linnéuniversitetet, Institutionen för biologi och miljö (BOM), Sweden.
    Kaczala, Fabio
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Charlotte, Marchand
    University of Montréal, Canada.
    Hogland, Marika
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Mait, Kriipsalu
    Estonian University of Life Sciences, Estonia.
    Hogland, William
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Anders, Kihl
    Ragn-Sells AB, Sollentuna.
    Characterisation of excavated fine fraction and waste composition from a Swedish landfill2016In: Waste Management & Research, ISSN 0734-242X, E-ISSN 1096-3669, Vol. 34, no 12, p. 1292-1299Article in journal (Refereed)
    Abstract [en]

    The present research studies the characterisation and the physico-chemical properties of an excavated fine fraction (<10 mm) from a Swedish landfill, the Högbytorp. The results showed that the fine fraction represents 38% by mass of the total excavated wastes and it contains mainly soil-type materials and minerals. Higher concentrations of zinc, copper, barium and chromium were found with concentrations higher than the Swedish Environmental Protection Agency (EPA) for contaminated soil. The found moisture and organic contents of the fine fraction were 23.5% and 16.6%, respectively. The analysed calorific value (1.7 MJ kg-1), the potential of CH4 (4.74 m3 t-1 dry matter) and Total Organic Carbon (TOC) (5.6%) were low and offer low potential of energy. Sieving the fine fraction further showed that 80% was smaller than 2 mm. The fine represents a major fraction at any landfill (40%–70%), therefore, characterising the properties of this fraction is essential to find the potential of reusing/recycling or safely redisposing.

  • 128.
    Jani, Yahya
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Molin, Hanna
    IVL Svenska Miljöinstitutet, | Hållbara verksamheter & konsumtion, Sweden.
    Jeppsson, Ulf
    Industriell elektroteknik och automation, Institutionen för biomedicinsk teknik, Lund Universitet, Sweden.
    Arnell, Magnus
    RISE Research Institutes of Sweden, Sweden.
    VA-kluster Mälardalen: Kunskapssammanställning om klustrets forskningsområden2023Report (Refereed)
    Abstract [sv]

    VA-kluster Mälardalen bildades år 2010 med syftet att samla regional forskningskompetensoch verksamhetsutövare inom VA-organisationer kring ett samarbete rörandereningstekniker, uppströmsarbete, resursåterföring och digitalisering inom VA-sektorn.Klustret utgörs idag av fem universitet, tretton VA-organisationer och två forskningsinstitut,som tillsammans forskar för en hållbar och resurseffektiv VA-sektor. Klustrets har drivitsamarbetet mellan VA-organisationer och lärosäten/institut på ett sätt som ger VAorganisationerna möjlighet att prioritera och initiera samarbetsprojekt inriktad på FoU samtrelevanta forskningsfrågor kopplade till VA-organisationers dagliga aktiviteter och verkligaproblem.Klustret har varit en viktig plattform för att såväl kommunicera och informeraforskningsresultat internt inom klustret som nationellt och internationellt inom de treprioriterade forskningsområdena: i) System och reningstekniker med närings- ochresursåterföring; ii) Metodik, teknik och kunskap för uppströmsarbete och hållbara kretslopp;och iii) Digitala tekniker för resurseffektiva avloppssystem. VA-kluster Mälardalen har totaltgenomfört cirka 100 forsknings- och utvecklingsprojekt fram tills nu. Många av projektenhar dessutom genomförts i samarbete med andra VA-organisationer utanför klustret samtmed internationella samarbetspartners. VA-kluster Mälardalen har bidragit med ökadkunskap och utveckling av framtida hållbara reningsverk i Sverige, EU och övriga världen. 

  • 129.
    Jansson, Johan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Lindberg, T
    Subramani, S
    Applications of physical models for optimization and control in pulp and paper industryConference paper (Other academic)
  • 130.
    Jaradat, M.
    et al.
    Energy Engineering Department, German Jordanian University, Amman, Jordan.
    Albatayneh, A.
    Energy Engineering Department, German Jordanian University, Amman, Jordan.
    Juaidi, A.
    An-Najah National University, Nablus, Palestine.
    Abdallah, R.
    An-Najah National University, Nablus, Palestine.
    Ayadi, O.
    The University of Jordan, Amman, Jordan.
    Ibbini, J.
    Hashemite University, Zarqa, Jordan.
    Campana, Pietro Elia
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Liquid desiccant systems for cooling applications in broilers farms in humid subtropical climates2022In: Sustainable Energy Technologies and Assessments, ISSN 2213-1388, E-ISSN 2213-1396, Vol. 51, article id 101902Article in journal (Refereed)
    Abstract [en]

    This paper intends to numerically analyse the performance of liquid desiccant systems on the supply air conditions for closed poultry barns. A commercially available evaporative cooler for poultry barns was modified into a desiccant dehumidifier by circulating desiccant solutions of LiCl-H2O and CaCl2-H2O instead of water. Ambient air conditions for one of humid and subtropical climates were simulated based on an ∊-NTU effectiveness model for an externally cooled liquid desiccant dehumidifier. Also, a distinctive temperature-humidity index (THI) was implemented to study the environmental thermal conditions that the poultry were subjected to. Concerning the thermal comfort for broilers, the results show that conventional direct evaporative cooling systems are not feasible when the ambient air is near saturation. The THI values for ambient and direct evaporative cooler were positioned mainly in the severe heat stress region, with THI value in the range of 80 to 82, and most air outlet conditions were near saturation. The numerical results for the liquid desiccant systems show a consistent reduction in humidity ratio and air dry-bulb temperature. The assessment of air outlet temperature and humidity in terms of THI values was shifted out of the emergency and danger zone with a preference for LiCl solution.

  • 131.
    Javed, Muhammad Shahzad
    et al.
    Shanghai Jiao Tong University, China.
    Jurasz, Jakub
    Wrocław University of Science and Technology, Poland.
    Guezgouz, Mohammad
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Canales, Fausto A.
    Universidad de la Costa, Colombia.
    Ruggles, Tyler H.
    Carnegie Institution for Science, Stanford, United States.
    Ma, Tao
    Shanghai Jiao Tong University, China.
    Impact of multi-annual renewable energy variability on the optimal sizing of off-grid systems2023In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 183, article id 113514Article in journal (Refereed)
    Abstract [en]

    It remains a significant technical and economic challenge to fully power large-scale grids with intermittent renewable energy (RE). Meanwhile, due to the rapid decrease in the cost of RE power generation technologies in recent years, the number of real-world implementations and studies dedicated to the optimal capacity sizing of renewable off-grid systems has increased. However, a common approach in the literature is to rely on typical single-year meteorological and demand data. A negative effect of this assumption is that it does not consider the RE inter-annual variability, which might cause blackouts or oversizing the system and large curtailments. This study employs 43 years of hourly solar, wind, and demand data, coupled with different microgrid configurations, to evaluate the impact of diverse simulation periods on the total system cost, optimal RE mix, and system reliability. Our findings indicate that extended simulation periods considerably increased renewable energy systems (RES) reliability and that the resulting configurations can be up to 94% more robust than those obtained using a single year of data. Additionally, the optimal energy storage requirements increased when considering longer simulation periods, indicating that short simulation periods could underestimate energy storage capacities in off-grid systems. The overestimations or underestimations resulting from optimizations based on single-year data directly affect the long-term sustainability, reliability, and cost-effectiveness of the RES.

  • 132.
    Javed, Muhammad Shahzad
    et al.
    Shanghai Jiao Tong Univ, Sch Mech Engn, Shanghai, Peoples R China..
    Ma, Tao
    Shanghai Jiao Tong Univ, Sch Mech Engn, Shanghai, Peoples R China..
    Jurasz, Jakob
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. AGH Univ Sci & Technol, Fac Management, Krakow, Poland..
    Ahmed, Salman
    Shanghai Jiao Tong Univ, Sch Mech Engn, Shanghai, Peoples R China..
    Mikulik, Jerzy
    AGH Univ Sci & Technol, Fac Management, Krakow, Poland..
    Performance comparison of heuristic algorithms for optimization of hybrid off-grid renewable energy systems2020In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 210, article id 118599Article in journal (Refereed)
    Abstract [en]

    Hybrid renewable energy systems have been widely acknowledged as a clean, affordable and reliable mechanism to generate electricity and to accomplish global sustainable development goals. In this study, first, an operating strategy and an optimization problem are developed for a hybrid, off-grid, solar-wind system based on pumped hydro battery storage, and then a non-linear optimization problem is described for the considered system. To solve the optimization problem, four different optimization techniques are employed i.e. ant colony (ACO), firefly algorithm (FA), particle swarm optimization (PSO) and genetic algorithm (GA) and their performance is compared using statistical parameters like relative error, mean absolute error and root mean square error. Each optimization technique's working principle is discussed in detail and formulated considering the proposed optimization problem. The exploration and exploitation behavior of each algorithm is comprehensively analyzed explaining that ACO and FA have higher exploitation behavior, while GA and PSO have more exploration behavior, revealing that these behavior depend on the range of operator controlling parameters, type of optimization problem and formulation structure of the optimizers. The reference controlling parameters of each optimizer (which are operator dependent) are defined for the proposed optimization problem. The results reveal that FA performs better - i.e. with the least relative error (0.126) - while PSO outperforms best in terms of least objective function value (0.2435 $/kWh). The mean efficiency of each algorithm in terms of repeated executions (30 times) is ACO = 95.94%, FA = 96.20%, GA = 93.93%, PSO = 96.20%. The proposed study could help decision-makers to choose an optimization method to solve non-linear problems in the context of storage-based, off-grid systems under different scenarios. (C) 2020 Elsevier Ltd. All rights reserved.

  • 133.
    Javed, Muhammad Shahzad
    et al.
    Shanghai Jiao Tong Univ, Sch Mech Engn, Shanghai, Peoples R China..
    Ma, Tao
    Shanghai Jiao Tong Univ, Sch Mech Engn, Shanghai, Peoples R China..
    Jurasz, Jakob
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. AGH Univ Sci & Technol, Fac Management, Krakow, Poland..
    Amin, Muhammad Yasir
    Shanghai Jiao Tong Univ, Sch Mech Engn, Shanghai, Peoples R China..
    Solar and wind power generation systems with pumped hydro storage: Review and future perspectives2020In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 148, p. 176-192Article, review/survey (Refereed)
    Abstract [en]

    It has been globally acknowledged that energy storage will be a key element in the future for renewable energy (RE) systems. Recent studies about using energy storages for achieving high RE penetration have gained increased attention. This paper presents a detailed review on pumped hydro storage (PHS) based hybrid solar-wind power supply systems. It also discusses the present role of PHS, its total installed capacity, future research and technical challenges associated with the use of this storage in the context of RE based systems. This review paper considers the economical, environmental and technical aspects of solar-wind-PHS systems which have been discussed in the papers published over last 10 years. Additionally, studies are categorized with respect to objective, approach employed, location and key findings. Reflected from the literature, PHS technology has again emerged as a technologically and economically viable option. The integration of reversible pump turbine machines has increased the flexibility, response time and performance of PHS, however, hybridization of PHS with other storages can increase the range of services and overall system reliability, especially when RE systems are off-grid. This review will be useful for researchers to explore RE-based PHS systems in the fields of modelling and techno-economic optimization. Hybrid storage, like the PHS-battery, is an emerging option to supplement the weakness of each other and will be a promising field for future research.

  • 134.
    Javed, Muhammad Shahzad
    et al.
    Shanghai Jiao Tong Univ, Sch Mech Engn, Shanghai, Peoples R China..
    Ma, Tao
    Shanghai Jiao Tong Univ, Sch Mech Engn, Shanghai, Peoples R China..
    Jurasz, Jakob
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Wroclaw Univ Sci & Technol, Fac Environm Engn, Wroclaw, Poland..
    Mikulik, Jerzy
    AGH Univ Sci & Technol, Fac Management, Krakow, Poland..
    A hybrid method for scenario-based techno-economic-environmental analysis of off-grid renewable energy systems2021In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 139, article id 110725Article in journal (Refereed)
    Abstract [en]

    Researchers have often overlooked the emissions problem during the suitable selection of renewable energy (RE) systems. Therefore, there is a need for an integrated framework that simultaneously considers the economic, technical and environmental criteria for the selection of the appropriate configuration. Firstly, a multi-objective optimization is performed using the epsilon- constraint method with a simulated annealing algorithm. Then a scenario-based method with a hybrid multi-criterion decision-making approach is used to rank all the available configurations. Five operating strategies are developed to make different configurations, i.e. battery only, pumped hydro storage (PHS), battery-diesel generator (DG), PHS-DG, and hybrid pumped-battery storage. A total of seven scenarios are made based on the weightage given to each main criterion. The study reveals that solar-wind-PHS-DG was the top-ranking alternative under four scenarios, solar-wind-PHS ranked first in two scenarios, and solar-wind-DG-battery got preference under the no-preference scenario; this shows that preferential selection (assigning a weighting to each criterion) significantly affects results. Emissions of all considered RE-based alternatives range from 0.072 to 0.148 kg (CO2 equivalent) per kWh of the served load. Furthermore, sensitivity analysis reveals that technical criteria conflict more with economic criteria than with environmental criteria. The impact of land requirements (an environmental sub-criterion) is visible in this study, indicating the high requirement of land for RE systems. The most appropriate configuration type is selected depending solely on the priorities defined by investors and policy-makers.

  • 135.
    Ji, H.
    et al.
    Key Laboratory of Smart Grid of Ministry of Education, Tianjin University, Tianjin, 300072, China.
    Chen, S.
    Key Laboratory of Smart Grid of Ministry of Education, Tianjin University, Tianjin, 300072, China.
    Yu, H.
    Key Laboratory of Smart Grid of Ministry of Education, Tianjin University, Tianjin, 300072, China.
    Li, P.
    Key Laboratory of Smart Grid of Ministry of Education, Tianjin University, Tianjin, 300072, China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Song, J.
    Global Energy Interconnection Research Institute of State Grid, Beijing, 100000, China.
    Wang, C.
    Key Laboratory of Smart Grid of Ministry of Education, Tianjin University, Tianjin, 300072, China.
    Robust operation for minimizing power consumption of data centers with flexible substation integration2022In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 248, article id 123599Article in journal (Refereed)
    Abstract [en]

    The rapid development of digital economy has led to a dramatic increasement of internet data centers (IDCs), which consume a large amount of electricity. The diverse data-processing demands, high power consumption and workload uncertainty put forward a high requirement for the economical and secure operation of IDCs. As information technology (IT) devices are driven by direct current (DC), flexible substation (FS) has been gradually utilized to provide DC power for IDCs. This paper proposes robust operation strategies for minimizing IDC power consumption with FS integration. First, the linearized IDC power consumption model based on the technology of dynamic voltage and frequency scaling (DVFS) is proposed to describe the operating state of IT devices. Then, considering the FS-based coordinated operation of IDC, photovoltaic (PV) station and energy storage system (ESS), the deterministic power consumption minimization model of IDCs is established. Considering the workload uncertainty, the operation strategies based on distributionally robust optimization (DRO) for IDCs are further proposed. Finally, the effectiveness of proposed method is validated on a modified practical network with IDCs integrated. Results show that through the dispatch of workload and power flow regulation of FS, the power consumption and dropping workload of IDCs are effectively reduced. 

  • 136.
    Ji, Haoran
    et al.
    School of Electrical and Information Engineering, Tianjin University, 12605 Tianjin, Tianjin, China.
    Jian, Jie
    School of Electrical and Information Engineering, Tianjin University, 12605 Tianjin, Tianjin, China.
    Yu, Hao
    School of Electrical and Information Engineering, Tianjin University, 12605 Tianjin, Tianjin, China.
    Ji, Jie
    School of Electrical and Information Engineering, Tianjin University, 12605 Tianjin, Tianjin, China.
    Wei, Mingjiang
    School of Electrical and Information Engineering, Tianjin University, 12605 Tianjin, Tianjin, China.
    Zhang, Xinmin
    State Grid Tianjin Electric Power Company, 561720 Tianjin, China.
    Li, Peng
    School of Electrical and Information Engineering, Tianjin University, 12605 Tianjin, Tianjin, China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wang, Chengshan
    Tianjin University, 12605 Tianjin, Tianjin, China.
    Peer-to-Peer Electricity Trading of Interconnected Flexible Distribution Networks Based on Distributed Ledger2022In: IEEE Transactions on Industrial Informatics, ISSN 1551-3203, E-ISSN 1941-0050, Vol. 18, no 9, p. 5949-5960Article in journal (Refereed)
    Abstract [en]

    The condition of power imbalance in flexible distribution networks (FDNs) is deteriorated due to the high penetration of distributed generators (DGs). Through peer-to-peer (P2P) electricity trading, multiple regions interconnected by soft open points (SOPs) can flexibly exchange power to alleviate power imbalance. As the physical foundation of P2P transactions, SOP regulation guarantees accurate instruction execution. Besides, smart contracts based on distributed ledger technology (DLT) facilitate highly credible P2P transactions. Oriented for the economic operation of interconnected FDNs, this paper proposes a DLT-based P2P electricity trading method based on intelligent SOP regulation. First, a smart contract is designed for P2P transactions of FDNs, in which trading solutions are automatically settled with a modified highest combined offer (HCO) principle. Then, a trading platform is built for the P2P electricity trading of interconnected FDNs. Finally, the effectiveness of the proposed method is verified on a practical FDN with four-terminal SOPs in Tianjin.

  • 137.
    Jiao, Yingqi
    et al.
    National Engineering Laboratory for Pipeline Safety/Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum-Beijing, Beijing, China.
    Qiu, Rui
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. National Engineering Laboratory for Pipeline Safety/Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum-Beijing, Beijing, China; .
    Liang, Yongtu
    National Engineering Laboratory for Pipeline Safety/Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum-Beijing, Beijing, China.
    Liao, Qi
    National Engineering Laboratory for Pipeline Safety/Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum-Beijing, Beijing, China.
    Tu, Renfu
    National Engineering Laboratory for Pipeline Safety/Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum-Beijing, Beijing, China.
    Wei, Xintong
    National Engineering Laboratory for Pipeline Safety/Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum-Beijing, Beijing, China.
    Zhang, Haoran
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Center for Spatial Information Science, The University of Tokyo, Chiba, Japan.
    Integration optimization of production and transportation of refined oil: A case study from China2022In: Chemical engineering research & design, ISSN 0263-8762, E-ISSN 1744-3563, Vol. 188, p. 39-49Article in journal (Refereed)
    Abstract [en]

    The logistics management of refined oil under a separation of production and transportation leads to high logistics costs and a mismatch between the supply and demand sides. This paper intends to develop a general framework to assess the impact of the integration of the production and transportation in terms of economic, environmental, and energy benefits. Firstly, this paper proposes a tactical-level mathematical model for optimizing the integration of production and transportation of refined oil to minimize the total cost. In the model, several factors, such as level of market demand, production capacity limits, transportation modes, and transportation capacity, are taken into consideration. Then, the energy, economy, and environment analysis method are applied to assess the impact of the integration on the field of refined oil logistics. Four scenarios are set up and a comparative analysis is carried out in detail in China. The optimal resource allocation scheme and production adjustment scheme for each scenario are obtained. The results show that after the integration, the logistics cost is reduced by 6.8 %− 11 %, the greenhouse gas emission is reduced by 7.3 %− 17.7 %, and the energy consumption per unit turnover is reduced by 4.4 %− 7.4 %. This proves that the integration of production and transportation guided by the proposed method performs positive economic, environmental, and energy benefits. Finally, policy implications are provided.

  • 138.
    Johansson, F.
    et al.
    Mälardalen University.
    Gustafsson, Bengt Erik
    Mälardalen University, School of Innovation, Design and Engineering, Innovation and Product Realisation.
    Stridh, Bengt
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Campana, Pietro Elia
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    3D-thermal modelling of a bifacial agrivoltaic system: a photovoltaic module perspective2022In: Energy Nexus, ISSN 2772-4271, Vol. 5, article id 100052Article in journal (Refereed)
    Abstract [en]

    This study presents a 3D computational fluid dynamic model to evaluate the temperature distribution and energy performances of a vertical bifacial photovoltaic module for agrivoltaic applications. This last is compared to a conventionally tilted bifacial photovoltaic module for ground-mounted applications. The simulations are performed in SolidWorks Flow Simulation® and validated with measured data gathered from the first experimental agrivoltaic system in Sweden. Additionally, four more simulations scenarios were defined to compare the performances of vertically mounted and conventionally tilted bifacial photovoltaic modules under different operating conditions

    The validation of the computational fluid dynamic model shows that the model tends to underestimate the readings performed with the thermal camera in the order of 3°C to 4°C for the vertical bifacial PV module. The comparison of the results obtained from the computational fluid dynamic model with existing models available in literature shows a good agreement. The comparison of the heat distribution from the computational fluid dynamic model and the thermal images also shows a good agreement. In all the scenarios investigated, the vertical bifacial photovoltaic module's overall efficiency was higher than that of the ground-mounted module due to lower average operating temperatures. The use of the computational fluid dynamic approach for studying the performance of a single photovoltaic module showed promising results that can be extended to study the system performance and microclimatic conditions.

  • 139.
    Jurasz, J.
    et al.
    Wrocław University of Science and Technology, Wrocław, Poland.
    Guezgouz, M.
    Mostaganem University, Mostaganem, Algeria.
    Campana, Pietro Elia
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Kies, A.
    Frankfurt Institute for Advanced Studies, Goethe University, Frankfurt, Germany.
    On the impact of load profile data on the optimization results of off-grid energy systems2022In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 159, article id 112199Article in journal (Refereed)
    Abstract [en]

    Access to electricity via large scale power grids is seen as one of the solutions for a fully renewable power system. However, it remains a huge technical, economical, and geopolitical challenge. In the meantime, millions of people across the world have none or limited access to electricity and quite often to rely on autonomous solutions such as diesel generators. With the decreasing cost of renewable energy generation technologies in recent years, one could observe a simultaneous increase in studies dedicated to optimal sizing of renewable off-grid systems. Many of these studies rely on the usage of typical daily load profiles to model the electricity demand, sometimes enhanced with seasonal or random components. Such approaches tend to overlook the existing potential case-specific correlation between availability of renewable energy and energy demand and in particular the natural variability of the load in terms of its extreme values or ramp rates. The objective of this study is to investigate the impact of different types of load input data (for instance real load, monthly adjusted typical load, and typical daily load) on the cost of energy provided by off-grid PV-battery systems supplying various loads with different reliability levels. For this purpose, we determine the optimal capacity of PV-battery systems based on commonly used energy management strategies and optimization algorithms. The analysis of the obtained results indicates that, on average, using daily load profiles tends to underestimate the cost by 1.2% points (pp) for a system with 100% reliability and by over 5 pp for a system characterized by 95% reliability. Using monthly adjusted typical daily load profiles leads to slight differences compared to the results obtained by using real load as input. Although the obtained average values indicate a tendency of underestimating the energy cost, some outliers have been also observed reaching values of up to 15% of overestimating the cost of energy.

  • 140.
    Jurasz, J.
    et al.
    Wrocław University of Science and Technology, Wrocław, Poland .
    Guezgouz, Mohammad
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Campana, Pietro Elia
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Kaźmierczak, B.
    Wrocław University of Science and Technology, Wrocław, Poland .
    Kuriqi, A.
    School of Geographical Sciences, University of Bristol, United Kingdom .
    Bloomfield, H.
    School of Geographical Sciences, University of Bristol, United Kingdom.
    Hingray, B.
    IGE, CNRS, GINP, IRD, Université Grenoble Alpes, Grenoble, France.
    Canales, F. A.
    Wrocław University of Science and Technology, Wrocław, Poland.
    Hunt, J. D.
    Energy, Climate, and Environment, International Institute for Applied Systems Analysis (IIASA) | Schlossplatz 1 | A-2361 Laxenburg, Austria .
    Sterl, S.
    Faculty of Engineering, Department of Water & Climate, Vrije Universiteit Brussel, Brussels, Belgium .
    Elkadeem, M. R.
    Interdisciplinary Research Center for Renewable Energy and Power Systems (IRC-REPS), King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia.
    Complementarity of wind and solar power in North Africa: Potential for alleviating energy droughts and impacts of the North Atlantic Oscillation2024In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 191, article id 114181Article in journal (Refereed)
    Abstract [en]

    With growing gas and oil prices, electricity generation based on these fossil fuels is becoming increasingly expensive. Furthermore, the vision of natural gas as a transition fuel is subject to many constraints and uncertainties of economic, environmental, and geopolitical nature. Consequently, renewable energies such as solar and wind power are expected to reach new records of installed capacity over the upcoming years. Considering the above, North Africa is one of the regions with the largest renewable resource potential globally. While extensively studied in the literature, these resources remain underutilized. Thus, to contribute to their future successful deployment and integration with the power system, this study presents a spatial and temporal analysis of the nature of solar and wind resources over North Africa from the perspective of energy droughts. Both the frequency and maximal duration of energy droughts are addressed. Both aspects of renewables’ variable nature have been evaluated in the North Atlantic Oscillation (NAO) context. The analysis considers the period between 1960 and 2020 based on hourly reanalysis data (i.e., near-surface shortwave irradiation, wind speed, and air temperature) and the Hurrel NAO index. The findings show an in-phase relationship between solar power and winter NAO index, particularly over the coastal regions in western North Africa and opposite patterns in its eastern part. For wind energy, the connection with NAO has a more zonal pattern, with negative correlations in the north and positive correlations in the south. Solar energy droughts dominate northern Tunisia, Algeria, and Morocco, while wind energy droughts mainly occur in the Atlas Mountains range. On average, solar energy droughts tend not to exceed 2–3 consecutive days, with the longest extending for five days. Wind energy droughts can be as prolonged as 80 days (Atlas Mountains). Hybridizing solar and wind energy reduces the potential for energy droughts significantly. At the same time, the correlation between their occurrence and the NAO index remains low. These findings show the potential for substantial resilience to inter-annual climate variability, which could benefit the future stability of renewables-dominated power systems. 

  • 141.
    Jurasz, Jakob
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Department of Engineering Management, AGH University of Science and Technology, Cracow, Poland.
    Ciapała, B.
    Department of Fossil Fuels, AGH University of Science and Technology, Cracow, Poland.
    A solar- and wind-powered charging station for electric buses based on a backup batteries concept2020In: ICT for Electric Vehicle Integration with the Smart Grid, Institution of Engineering and Technology , 2020, p. 317-336Chapter in book (Other academic)
    Abstract [en]

    This chapter focuses on a solar- and wind-powered charging station for electric buses, which is equipped with a set of backup batteries that serve as energy storage. Additional batteries are used to compensate for the variable and stochastic energy generation of the climate-driven solar and wind sources. The research presented here focuses on analysing the charging station’s reliability in terms of covering observed load, its economic performance, impact on the power system and the potential to reduce greenhouse gas emissions (in CO2 equivalent). The results show that such a station can not only minimise electric buses’ impact on the environment and ensure satisfactory reliability levels but also be a profitable investment.

  • 142.
    Jurasz, Jakob
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. AGH Univ Sci & Technol, Al Mickiewicza 30, PL-30059 Krakow, Poland..
    Piasecki, Adam
    Nicolaus Copernicus Univ, Lwowska 1, PL-87100 Torun, Poland..
    Kazmierczak, Bartosz
    Wroclaw Univ Sci & Technol, Wyb Wyspianskiego 27, PL-50370 Wroclaw, Poland..
    Sewage Volume Forecasting on a Day-Ahead Basis - Analysis of Input Variables Uncertainty2019In: JOURNAL OF ECOLOGICAL ENGINEERING, ISSN 2299-8993, Vol. 20, no 9, p. 70-79Article in journal (Refereed)
    Abstract [en]

    Water consumption and the resulting sewage volume (both strongly impacted by meteorological parameters) are of key importance for an efficient and sustainable operation of waterworks and wastewater treatment plants. Therefore, the objective of this research is to analyze the potential impact of input variables uncertainty on the performance of sewage volume forecasting model. The research is based on a real, three-year long, daily time series collected from Torun (Poland). The used time series encompassed: sewage volume, water consumption, rainfall, temperature, precipitation, evaporation, sunshine duration and precipitation at a six hours interval. Neural network has been selected as a forecasting tool a multi-layer perceptron artificial., a simulation model for the sewage volume was created which considered the above-mentioned time series as exogenous variables. Further, its performance was tested assuming that all non-historical input variables are prone to their individual forecasting errors. The analysis was dedicated firstly to each variable individually and later the potential of all of them being uncertain was tested. A lack of correlation between the input variables error was assumed. The research provides an interesting solution for visualizing the quality and actual performance of forecasting models where some or all of input variables has to be forecast.

  • 143.
    Jurasz, Jakob
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. AGH Univ Sci & Technol, Fac Management, Dept Engn Management, PL-30059 Krakow, Poland..
    Wdowikowski, Marcin
    Natl Res Inst, Inst Meteorol & Water Management, PL-01673 Warsaw, Poland..
    Figurski, Mariusz
    Natl Res Inst, Inst Meteorol & Water Management, PL-01673 Warsaw, Poland.;Gdansk Univ Technol, Fac Civil & Environm Engn, PL-80233 Gdansk, Poland..
    Simulating Power Generation from Photovoltaics in the Polish Power System Based on Ground Meteorological Measurements-First Tests Based on Transmission System Operator Data2020In: Energies, E-ISSN 1996-1073, Vol. 13, no 16, article id 4255Article in journal (Refereed)
    Abstract [en]

    The Polish power system is undergoing a slow process of transformation from coal to one that is renewables dominated. Although coal will remain a fundamental fuel in the coming years, the recent upsurge in installed capacity of photovoltaic (PV) systems should draw significant attention. Owning to the fact that the Polish Transmission System Operator recently published the PV hourly generation time series in this article, we aim to explore how well those can be modeled based on the meteorological measurements provided by the Institute of Meteorology and Water Management. The hourly time series of PV generation on a country level and irradiation, wind speed, and temperature measurements from 23 meteorological stations covering one month are used as inputs to create an artificial neural network. The analysis indicates that available measurements combined with artificial neural networks can simulate PV generation on a national level with a mean percentage error of 3.2%.

  • 144.
    Juura, Jonaz
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Analys av antagnings- och genomströmningsmått för utbild­ningsprogram: Förslag till och exempel på tillämpning av en registerbaserad uppföljningsmetod2019Report (Other academic)
    Abstract [sv]

    Utifrån krav på breddad rekrytering av studenter till utbildningar vid landets lärosäten kan goda skäl finnas att följa upp genomströmningen inom olika ut­bild­­nings­program. Därtill har fakultetsnämnden vid Mälardalens högskola beslutat om en modell för upp­följning av lärosätets utbildningar utifrån den kvali­tets­policy som tidigare har fastställts. I denna policy betonas att det sys­te­matiska kvalitets­arbetet ska årligen genom­föras nära verksamheten samt ska utgå från det dagliga kvalitets­arbetet som bedrivs vid hög­skolan. Modellen för hur uppföljningen ska genomföras beskrivs i sju punkter, varav den fjärde punkten avser analyser av utbild­ningsprogram. Föreliggande studie kan ses som ett komplement till denna punkt, då studien berör vissa moment som ingår i pro­gramanalysen: söktryck samt genom­strömning och prestationsgrad.

    Till skillnad från den årliga analysen enligt ovan nämnda modell har denna studie en mätperiod som sträcker sig över flera års studentkohorter, för att där­igenom illustrera och analysera utvecklingen över tid. För detta har ingen före­slagen arbetsmodell funnits till hands, varför syftet för studien har varit att både utveckla ett utkast till metod för registerbaserad uppföljning av olika utbild­ningsprogram samt att med den föreslagna metoden genomföra en uppföljning av ett utvalt utbildnings­program inom Akademin för samhälle, ekonomi och teknik – Högskoleingenjörsprogrammet i byggnadsteknik om 180 hp. Rap­porten redo­gör således både för en utförd uppföljning av nämnda utbild­nings­program och för en beskrivning av metoden.

    Uppföljningen baseras på data hämtade från antagningssystemet NyA och studie­doku­menta­tionssystemet Ladok. Inför analysen har dessa data legat till grund för framtagning av jämförbara antagningsmått för det nämnda ut­bild­nings­programet – antagningsgrad, sammansättning av studentkohorter utifrån urvals­grupper samt meritmedelvärden – samt följande mått för genom­ström­ningen: kvarvaro­grad, prestationsgrad och examensgrad. De sex student­ko­horter som omfattas av analysens mätperiod påbörjade programmet under perio­den 2010−2015.

    Studiens resultat pekar i korthet och i huvudsak på att antag­nings­graden för pro­grammet har minskat betydligt under mätperioden, samtidigt som merit­medelvärdena har ökat – i synnerhet för den ca tredjedelen av studenterna som antagits via resultat vid högskoleprov. Vidare framkommer att såväl kvar­varo­graden som presta­tionsgraden har ökat över tid, samt att under senare hälften av mät­perioden så har studenterna i genomsnitt erhållit sina poäng snabbare än de föregående student­kohorterna. Den ökade kvarvarograden samvarierade i huvudsak med a) minskad antagningsgrad, b) ökad andel studenter från urvals­grupperna betyg utan kom­pletteringar från gymnasieskolans gamla respektive nya betygssystem samt med c) ökade merit­medelvärden. Detta medan den ökade prestationsgraden i huvudsak samvarierade endast med a) minskad an­tag­nings­grad och b) ökade meritmedelvärden. Således ser studentkohorternas samman­sättning utifrån urvalsgrupper ut att ha haft större inverkan på kvar­varograden än på prestationsgraden. Prestationsgradens ökning var dessutom större än kvarvarogradens, vilket kan indikera en ökad poängeffektiviteten i genom­ström­ningen under mätperioden. Dock framstod examens­graden som något pro­ble­matisk, då den varierade tämligen stort under mätperioden och varken följde utvecklingsmönstret för merit­medel­värdena, kvarvaro- eller pre­sta­­tions­graden, och inte heller förändringar i studentkohorternas sammansättning utifrån urvals­grupper.

    I jämförelser med studier utförda av Universitetskanslerämbetet samt Uni­versitets- och hög­skole­rådet framkommer att antagningsgraden för det gran­skade programmet var betydligt lägre än på generell nationell nivå, men också att den sjönk mer under mätperioden. Vidare framkommer inte endast att kvar­varo­graden gott och väl var i paritet med andra högskoleingenjörsprogram i landet, dessutom stod den sig mycket väl i en jämförelse med andra högskole­ingenjörsprogram inom lärosätet. Ökad prestationsgrad var också gemen­sam med utvecklingen på nationell nivå. Dock var ökningen större för det granskade pro­grammet på grund av låg prestationsgrad vid mätperiodens inledning. Vid dess slut hade nivån för prestationsgraden närmat sig de andra yrkesexamens- och gene­rella programmens prestationsgrader. Examensgradens varierande ut­vecklings­trend framstod dock fortfarande som problematisk, och nivåerna var i genom­snitt betydligt lägre än för högskoleingenjörsprogram på nationell nivå. Vidare kan de ökade meritmedelvärdena – i synnerhet gällande resultat från hög­skole­prov – också eventuellt framstå som pro­blematiska om effektivitets- och ekonomi­perspektivet för läro­sätets del ställs mot kravet på breddad rekrytering, vilket inte har analyserats här men som bör ingå i framtida eller kompletterande uppföljningar/utvärderingar.

    I rapportens senare del diskuteras metodologiska aspekter på studien – i synner­het skillnader i mätmetoder jämfört med UKÄ:s årsrapporter – samt reflek­tioner inför fram­tida uppföljningsstudier. Rapporten avslutas med en genom­gång av de väsentligaste metodologiska handgreppen som har gällt för in­hämtning och analys av data.

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  • 145.
    Kamranfar, S.
    et al.
    Department of Architecture, Built Environment and Construction Engineering, Politecnico di Milano, Milan, 20133, Italy.
    Damirchi, F.
    Construction Engineering and Management, Department of Civil Engineering, Payame Noor University, Tehran, 19395-4697, Iran.
    Pourvaziri, M.
    Department of Architecture, University of Tehran, Tehran, 14395 515, Iran.
    Abdunabi Xalikovich, P.
    Department of Accounting, Tashkent Institute of Finance, Tashkent, 10012, Uzbekistan.
    Mahmoudkelayeh, S.
    Department of Architecture, University of Tehran, Tehran, 14395 515, Iran.
    Moezzi, R.
    Association of Talent under Liberty in Technology (TULTECH), Tallinn, 10615, Estonia .
    Vadiee, Amir
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    A Partial Least Squares Structural Equation Modelling Analysis of the Primary Barriers to Sustainable Construction in Iran2023In: Sustainability, E-ISSN 2071-1050, Vol. 15, no 18, article id 13762Article in journal (Refereed)
    Abstract [en]

    This paper outlines the obstacles to sustainable construction growth in Iran and thereafter examines the effect and relation between these barriers and the direction of sustainable construction growth as one of the essential objectives for achieving sustainable cities and infrastructure. The study is applied for research purposes that are based on descriptive survey data gathering and correlational data analysis techniques. The statistical population for this study consists of 120 construction-related engineers and university professors who were assessed on a five-point Likert scale. Using SmartPLS software version 4, the responses to the questionnaire were examined. The Kolmogorov–Smirnov assessment was utilized to evaluate the normalcy of the variables, as this assessment is typically employed for this purpose. For data analysis, the PLS (partial least squares) method was used, while SEM (structural equation modeling) methods have been used to assess the study hypotheses. Cronbach’s alpha and the composite reliability coefficient (CR) were applied to determine the instrument’s viability, and the results show that the coefficient connected to all variables is above 7.0, which is an acceptable value. The AVE (average variance extracted) was also used to evaluate the questionnaire’s validity, which was greater than 0.4 and deemed acceptable for coefficients of significance (T-values), coefficient of predictive power (Q2), and coefficient of determination (R2). The obtained results support and confirm all research hypotheses, including that the identified obstacles directly affect the performance of sustainable construction. According to the results of the Friedman test, the legal restrictions variable (CL) is the most significant obstacle to sustainable construction in Iran, with a rank of 4.24. The indicators of political limits (CP) and social and cultural constraints (CSC) came in at second and third, respectively. The results could help government officials make better decisions about where to focus their attention and how to distribute scarce resources. 

  • 146.
    Kapica, J.
    et al.
    Department of Technology Fundamentals, University of Life Sciences, Lublin, Poland.
    Jurasz, J.
    Wrocław University of Science and Technology, Wrocław, Poland.
    Canales, F. A.
    Wrocław University of Science and Technology, Wrocław, Poland.
    Bloomfield, H.
    School of Geographical Sciences, University of Bristol, Bristol, United Kingdom.
    Guezgouz, Mohammad
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    De Felice, M.
    European Commission, Joint Research Centre, Petten, Netherlands.
    Zbigniew, K.
    Department of Technology Fundamentals, University of Life Sciences, Lublin, Poland.
    The potential impact of climate change on European renewable energy droughts2024In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 189, article id 114011Article in journal (Refereed)
    Abstract [en]

    The daily, seasonal, and interannual variability of solar and wind resources is well-documented, based on evidence from multi-decadal meteorological time series. However, with the growing share of non-dispatchable renewable-based power sources (e.g., wind and solar power), the stable operation of the power system could be undermined by prolonged periods of low availability of these resources. Consequently, this may result in extremely high prices in the energy market or even a power system blackout. This study analyzes the performance of solar, wind, and solar-wind hybrid systems in Europe based on eight regional climate models, considering two possible climate change projections. The resource availability has been evaluated based on the energy drought concept. The total duration of droughts is calculated using daily capacity factors covering the years 1970–2020 (reference period) and 2048–2098 (future period), considering sub-national regions across the whole of Europe. In general, the chosen climate models show a more significant agreement in the occurrence of energy droughts for northern and southern Europe compared to its central part. Assessing the potential for renewable energy droughts is critical to maintaining secure and reliable power system operation in both the present and future climate.

  • 147.
    Karlsson, Simon
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Farman, Farman
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    HEAT CONSUMPTION OPTIMIZATION IN 4TH GENERATION DISTRICT HEATING: Study on utilizing low temperature heat sources and heat stored in a house by varying indoor temperature2023Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    4th generation district heating (4GDH) and varying the indoor temperature to store heat are both important concepts that can make it easier to implement more renewable energy and reduce costs of heating. This study looks at these concepts from a customer perspective using one building and looking at how energy can be stored and the performance of 4GDH. Low temperature heat sources from industry, supermarkets, and datacentres are used in combination with heat from a combined heat and power plant to get the required heating. A heat pump has also been modelled as a part of the 4GDH structure. In addition to looking at heat storage in 4GDH a scenario with direct electric heating has also been evaluated. In conclusion 4GDH has lower operating costs than 3rd generation district heating, but it is not worth varying the indoor temperature to store energy when using 4GDH. It is, however, profitable to vary indoor temperature if direct electric heating is used.

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  • 148.
    Kavvalos, Mavroudis
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Diamantidou, Eirini
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Claesson, J.
    Modelon AB, Lund, 22370, Sweden.
    Sielemann, M.
    Modelon Deutschland GmbH, Munich, 80992, Germany.
    Exploring Design Trade-Offs for Installed Parallel Hybrid Powertrain Systems2021In: 2021 AIAA/IEEE Electric Aircraft Technologies Symposium, EATS 2021, Institute of Electrical and Electronics Engineers Inc. , 2021Conference paper (Refereed)
    Abstract [en]

    The parallel hybrid (or boosted) turbofan engine alleviates the system complexity of radical electrified powertrain architectures, while also demonstrates substantial benefits in reducing specific fuel consumption. This conservative, yet promising, electrified configuration incorporates an electrical drive coupled with the engine low-pressure or gearbox fan spool. Sophisticated models for the gas turbine and the electrical drive system are developed. The former deploys a multi-point design matching scheme coupled with an installed engine performance approach, as well as an engine sizing and weight estimation tool. The latter incorporates an analytical electrical machine sizing and performance methodology. The objective of this paper is to shed light on the optimal parallel hybrid engine design, considering installed cycle performance and tight coupling of engine and electrical drive systems. The impact of installation drag components on the integrated powertrain system performance is analyzed and design trade-offs are explored. Electrical machine efficiency, propulsion system weight and installed specificfuelconsumptiondemonstrateopposingtrendswithvaryingspecificthrustfordifferent electrical drive installation positions and mechanical connections. It is shown that fan spinner-mounted electrical machine which is mechanically coupled to the low-pressure spool presents the greatest potential in terms of electrical machine efficiency and propulsion system installed performance. A 11.23% and 15.11% increase in installed specific fuel consumption at Top of Climb and Cruise, respectively, is observed for the Cruise-based optimal specific thrust variant, rendering installation effects and electrical drive considerations critical for future low-specific thrust hybrid-electric aero-engine concepts. 

  • 149.
    Kavvalos, Mavroudis
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Padulo, M.
    AURA-AERO, Cugnaux, 312 70, France.
    The Growth Engine Concept and Its Potential for an Electrified Aviation Future2024In: Journal of engineering for gas turbines and power, ISSN 0742-4795, E-ISSN 1528-8919, Vol. 146, no 7, article id 070901Article in journal (Refereed)
    Abstract [en]

    The emerging need for cost- and energy-efficient propulsion systems have shifted the research interest to radical concepts, with several challenges to overcome in order to enter into service. However, revitalizing old yet provably successful engine designs-a practice followed by engine manufacturers over the years-can provide low-risk alternative solutions to move immediate market demands. The paper reviews this approach, known as concept of growth engines or core commonality, and investigates how a geometrically fixed or geometrically similar engine core can be utilized across a family of engines. The development programs of the highly successful CFM56 and PT6 engine families are analyzed, proving the success of this concept over the years. The idea is based on the engineering paradigm of product families and is briefly presented from a theoretical perspective. Implementation methods and simulation tools to initiate, conceptualize, design, and evaluate an engine family program are reviewed. The potential application of engine core commonality into electrified propulsion systems is investigated. Design challenges and opportunities that electrification imposes to the growth engine concept are discussed. Finally, the concept of growth electrified propulsion systems is introduced, conveying future research directions to achieve a successful family of engines for electrified applications.

  • 150.
    Khan, Zarrar
    et al.
    Pacific Northwest Natl Lab PNNL, Joint Global Change Res Inst JGCRI, College Pk, MD 20740 USA..
    Abraham, Edo
    Delft Univ Technol, Dept Water Resources Management, Delft, Netherlands..
    Aggarwal, Srijan
    Univ Alaska Fairbanks, Coll Engn & Mines, Fairbanks, AK USA..
    Khan, Manal Ahmad
    Natl Geog Partners, Washington, DC USA..
    Arguello, Ricardo
    Unidad Planificac Rural Agr UPRA, Bogota, Colombia..
    Babbar-Sebens, Meghna
    Oregon State Univ, Sch Civil & Construct Engn, Coll Engn, Corvallis, OR 97331 USA..
    Bereslawski, Julia Lacal
    Banco Interamer Desarrollo, Buenos Aires, DF, Argentina..
    Bielicki, Jeffrey M.
    Ohio State Univ, Dept Civil Environm & Geodet Engn, Columbus, OH 43210 USA.;Ohio State Univ, John Glenn Coll Publ Affairs, Columbus, OH 43210 USA..
    Campana, Pietro Elia
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Carrazzone, Maria Eugenia Silva
    FAO, Rome, Italy..
    Emerging Themes and Future Directions of Multi-Sector Nexus Research and Implementation2022In: Frontiers in Environmental Science, E-ISSN 2296-665X, Vol. 10, article id 918085Article in journal (Refereed)
    Abstract [en]

    Water, energy, and food are all essential components of human societies. Collectively, their respective resource systems are interconnected in what is called the "nexus". There is growing consensus that a holistic understanding of the interdependencies and trade-offs between these sectors and other related systems is critical to solving many of the global challenges they present. While nexus research has grown exponentially since 2011, there is no unified, overarching approach, and the implementation of concepts remains hampered by the lack of clear case studies. Here, we present the results of a collaborative thought exercise involving 75 scientists and summarize them into 10 key recommendations covering: the most critical nexus issues of today, emerging themes, and where future efforts should be directed. We conclude that a nexus community of practice to promote open communication among researchers, to maintain and share standardized datasets, and to develop applied case studies will facilitate transparent comparisons of models and encourage the adoption of nexus approaches in practice.

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