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  • 1.
    Chen, Hao
    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.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Retrofitting Biomass Combined Heat and Power Plant for Biofuel Production-A Detailed Techno-Economic Analysis2024In: Energies, E-ISSN 1996-1073, Vol. 17, no 2, article id 522Article in journal (Refereed)
    Abstract [en]

    Existing combined heat and power plants usually operate on part-load conditions during low heating demand seasons. Similarly, there are boilers designated for winter use that remain inactive for much of the year. This brings a concern about the inefficiency of resource utilization. Retrofitting existing CHP plants (especially for those with spare boilers) for biofuel production could increase revenue and enhance resource efficiency. This study introduces a novel approach that combines biomass gasification and pyrolysis in a polygeneration process that is based on utilizing existing CHP facilities to produce biomethane, bio-oil, and hydrogen. In this work, a detailed analysis was undertaken of retrofitting an existing biomass combined heat and power plant for biofuel production. The biofuel production plant is designed to explore the polygeneration of hydrogen, biomethane, and bio-oil via the integration of gasification, pyrolysis, and renewable-powered electrolysis. An Aspen Plus model of the proposed biofuel production plant is established followed by a performance investigation of the biofuel production plant under various design conditions. An economic analysis is carried out to examine the profitability of the proposed polygeneration system. Results show that the proposed polygeneration system can achieve 40% carbon efficiency with a payback period of 9 years and an internal rate of return of 17.5%, without the integration of renewable hydrogen. When integrated with renewable-power electrolysis, the carbon efficiency could be significantly improved to approximately 90%; however, the high investment cost associated with the electrolyzer system makes this integration economically unfavorable.

  • 2.
    Ciapala, Bartlomiej
    et al.
    AGH Univ Sci & Technol, Fac Geol Geophys & Environm Protect, Dept Fossil Fuels, PL-30059 Krakow, Poland..
    Jurasz, Jakob
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. AGH Univ Sci & Technol, Fac Management, Dept Engn Management, PL-30059 Krakow, Poland..
    Kies, Alexander
    Goethe Univ, Frankfurt Inst Adv Studies, D-60438 Frankfurt, Germany..
    The Potential of Wind Power-Supported Geothermal District Heating Systems-Model Results for a Location in Warsaw (Poland)2019In: Energies, E-ISSN 1996-1073, Vol. 12, no 19, article id 3706Article in journal (Refereed)
    Abstract [en]

    Geothermal heat is considered a sustainable energy source with significant global potential. Together with heat distribution networks, it can provide clean thermal energy to individual and commercial consumers. However, peaks in heat demand can require additional peaking sources at times. In this paper, we investigated how wind turbines can act as a peak energy source for a geothermal district heating system. We studied a model consisting of a geothermal heat source, a heat storage and wind power generator using historical weather data of Warsaw (Poland) and showed that wind power could increase the renewable share to supply a considerable heat demand compared to a geothermal heat source alone. The results indicate that wind power can be a suitable complement for a geothermal heat source to provide energy for heating. It is shown that a theoretical geo-wind-thermal storage based district heating network supplying 1000 m(2), which requires 100 W/m(2) at an outdoor temperature of -20 degrees C should have the following parameters: 4.8 MWh of thermal energy storage capacity, 45 kW of geothermal capacity and 5 kW of wind capacity. Such a system would ensure minimal wind curtailment, high utilization of geothermal source and high reliability of supply.

  • 3.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Chirumalla, Koteshwar
    Mälardalen University, School of Innovation, Design and Engineering, Innovation and Product Realisation.
    Toorajipour, Reza
    Mälardalen University, School of Innovation, Design and Engineering, Innovation and Product Realisation.
    Johansson, Glenn
    Mälardalen University, School of Innovation, Design and Engineering, Innovation and Product Realisation. Department of Design Sciences, Lund University, 221 00 Lund, Sweden.
    Balancing Power in Sweden Using Different Renewable Resources, Varying Prices, and Storages Like Batteries in a Resilient Energy System2023In: Energies, E-ISSN 1996-1073, Vol. 16, no 12, p. 4734-4734Article in journal (Refereed)
    Abstract [en]

    In this paper, balancing electricity production using renewable energy such as wind power, PV cells, hydropower, and CHP (combined heat and power) with biomass is carried out in relation to electricity consumption in primarily one major region in Sweden, SE-3, which contains 75% of the country's population. The time perspective is hours and days. Statistics with respect to power production and consumption are analyzed and used as input for power-balance calculations. How long periods are with low or high production, as well as the energy for charge and discharge that is needed to maintain a generally constant power production, is analyzed. One conclusion is that if the difference in production were to be completely covered with battery capacity it would be expensive, but if a large part of the difference were met by a shifting load it would be possible to cover the rest with battery storage in an economical way. To enhance the economy with battery storage, second-life batteries are proposed to reduce the capital cost in particular. Batteries are compared to hydrogen as an energy carrier. The efficiency of a battery system is higher than that of hydrogen plus fuel cells, but in general much fewer precious materials are needed with an H-2/fuel-cell system than with batteries. The paper discusses how to make the energy system more robust and resilient.

  • 4.
    Desideri, Umberto
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Department of Energy, Systems, Territory and Construction Engineering, University of Pisa, Pisa, 56122, Italy.
    Krayem, A.
    Department of Energy, Systems, Territory and Construction Engineering, University of Pisa, Pisa, 56122, Italy.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    The Unprecedented Natural Gas Crisis in Europe: Investigating the Causes and Consequences with a Focus on Italy2023In: Energies, E-ISSN 1996-1073, Vol. 16, no 16, article id 5954Article in journal (Refereed)
    Abstract [en]

    The energy prices in Europe have in recent years surpassed unprecedented thresholds and varied in unexpected ways compared to previous years. This paper presents a study of the fuel markets in Italy, supplemented by insights from Sweden. Italy is heavily dependent on natural gas. The results show that natural gas demand changed only slightly in the period 2017–2022, but prices started to increase at the end of 2021. Notable spikes occurred at the beginning of the events in Ukraine, even though the baseline was already three times higher than the average price from 2017 to 2019. Distinct dynamics can be identified with the increase in demand for power generation, contrasted with a decrease in industrial natural gas demand after August 2022. The trends in coal and wood chip prices are consistent with those of natural gas, while oil prices appear to be less correlated. Additionally, events such as CO2 trading and the launch of the Fit for 55 program by the EU show some correlation with the trend in natural gas prices during 2021. Interestingly, the origin of the increase in natural gas prices during 2021–2022 cannot be simply attributed to the mismatch of supply and demand or any singular external event. This paper aims at starting a discussion on the topic by proposing some explanations.

  • 5.
    Effatpisheh, Aref
    et al.
    Shiraz Univ Technol, Dept Mech & Aerosp Engn, Shiraz 71557, Iran.
    Vadiee, Amir
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Monfared, Behzad A.
    KTH Royal Inst Technol, Sweden.
    Mathematical Modelling of Active Magnetic Regenerator Refrigeration System for Design Considerations2020In: Energies, E-ISSN 1996-1073, Vol. 13, no 23, article id 6301Article in journal (Refereed)
    Abstract [en]

    A magnetic refrigeration system has the potential to alternate the compression system with respect to environmental compatibility. Refrigeration systems currently operate on the basis of the expansion and compression processes, while active magnetic refrigeration systems operate based on the magnetocaloric effect. In this study, a single layer of Gd was used as the magnetocaloric material for six-packed-sphere regenerators. A one-dimensional numerical model was utilized to simulate the magnetic refrigeration system and determine the optimum parameters. The optimum mass flow rate and maximum cooling capacity at frequency of 4 Hz are 3  and 580 W, respectively. The results show that the maximum pressure drop increased by 1400 W at a frequency of 4 Hz and mass flow rate of 5 . In this study, we consider the refrigeration system in terms of the design considerations, conduct a parametric study, and determine the effect of various parameters on the performance of the system.

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  • 6.
    Eriksson, O.
    et al.
    Department of Building, Energy and Environmental Engineering, Faculty of Engineering and Sustainable Development, University of Gävle, Sweden.
    Hadin, Å.
    Department of Building, Energy and Environmental Engineering, Faculty of Engineering and Sustainable Development, University of Gävle, Sweden.
    Hennessy, Jay
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation. SP Technical Research Institute of Sweden, Borås, Sweden.
    Jonsson, D.
    Department of Building, Energy and Environmental Engineering, Faculty of Engineering and Sustainable Development, University of Gävle, Sweden.
    Life cycle assessment of horse manure treatment2016In: Energies, E-ISSN 1996-1073, Vol. 9, no 12, article id 1011Article in journal (Refereed)
    Abstract [en]

    Horse manure consists of feces, urine, and varying amounts of various bedding materials. The management of horse manure causes environmental problems when emissions occur during the decomposition of organic material, in addition to nutrients not being recycled. The interest in horse manure undergoing anaerobic digestion and thereby producing biogas has increased with an increasing interest in biogas as a renewable fuel. This study aims to highlight the environmental impact of different treatment options for horse manure from a system perspective. The treatment methods investigated are: (1) unmanaged composting; (2) managed composting; (3) large-scale incineration in a waste-fired combined heat and power (CHP) plant; (4) drying and small-scale combustion; and (5) liquid anaerobic digestion with thermal pre-treatment. Following significant data uncertainty in the survey, the results are only indicative. No clear conclusions can be drawn regarding any preference in treatment methods, with the exception of their climate impact, for which anaerobic digestion is preferred. The overall conclusion is that more research is needed to ensure the quality of future surveys, thus an overall research effort from horse management to waste management.

  • 7.
    Feng, D.
    et al.
    China Energy Engineering Group Jiangsu Power Design Institute Co., Ltd., Nanjing, 210012, China.
    Xu, W.
    China Energy Engineering Group Jiangsu Power Design Institute Co., Ltd., Nanjing, 210012, China.
    Gao, X.
    Institute of the Building Environment & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an, 710049, China.
    Yang, Y.
    China Energy Engineering Group Jiangsu Power Design Institute Co., Ltd., Nanjing, 210012, China.
    Feng, S.
    China Energy Engineering Group Jiangsu Power Design Institute Co., Ltd., Nanjing, 210012, 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.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Carbon Emission Prediction and the Reduction Pathway in Industrial Parks: A Scenario Analysis Based on the Integration of the LEAP Model with LMDI Decomposition2023In: Energies, E-ISSN 1996-1073, Vol. 16, no 21, article id 7356Article in journal (Refereed)
    Abstract [en]

    Global climate change imposes significant challenges on the ecological environment and human sustainability. Industrial parks, in line with the national climate change mitigation strategy, are key targets for low-carbon revolution within the industrial sector. To predict the carbon emission of industrial parks and formulate the strategic path of emission reduction, this paper amalgamates the benefits of the “top-down” and “bottom-up” prediction methodologies, incorporating the logarithmic mean divisia index (LMDI) decomposition method and long-range energy alternatives planning (LEAP) model, and integrates the Tapio decoupling theory to predict the carbon emissions of an industrial park cluster of an economic development zone in Yancheng from 2020 to 2035 under baseline (BAS) and low-carbon scenarios (LC1, LC2, and LC3). The findings suggest that, in comparison to the BAS scenario, the carbon emissions in the LC1, LC2, and LC3 scenarios decreased by 30.4%, 38.4%, and 46.2%, respectively, with LC3 being the most suitable pathway for the park’s development. Finally, the paper explores carbon emission sources, and analyzes emission reduction potential and optimization measures of the energy structure, thus providing a reference for the formulation of emission reduction strategies for industrial parks. 

  • 8.
    Gluesenkamp, K. R.
    et al.
    Oak Ridge National Laboratory, Oak Ridge, United States.
    Frazzica, A.
    Consiglio Nazionale delle Ricerche (CNR), Messina, Italy.
    Velte, A.
    Fraunhofer Institute for Solar Energy Systems ISE, Freiburg, Germany.
    Metcalf, S.
    University of Warwick, Coventry, United Kingdom.
    Yang, Z.
    Oak Ridge National Laboratory, Oak Ridge, United States.
    Rouhani, M.
    Simon Fraser University, Surrey, Canada.
    Blackman, Corey
    SaltX Technology AB, Sweden.
    Qu, M.
    Purdue University, West Lafayette, United States.
    Laurenz, E.
    Fraunhofer Institute for Solar Energy Systems ISE, Freiburg, Germany.
    Rivero‐Pacho, A.
    University of Warwick, Coventry, United Kingdom.
    Hinmers, S.
    University of Warwick, Coventry, United Kingdom.
    Critoph, R.
    University of Warwick, Coventry, United Kingdom.
    Bahrami, M.
    Simon Fraser University, Surrey, Canada.
    Füldner, G.
    Fraunhofer Institute for Solar Energy Systems ISE, Freiburg, Germany.
    Hallin, I.
    HeatAmp Sweden AB, Stockholm, Sweden.
    Experimentally measured thermal masses of adsorption heat exchangers2020In: Energies, E-ISSN 1996-1073, Vol. 13, no 5, article id 1150Article in journal (Refereed)
    Abstract [en]

    The thermal masses of components influence the performance of many adsorption heat pump systems. However, typically when experimental adsorption systems are reported, data on thermal mass are missing or incomplete. This work provides original measurements of the thermal masses for experimental sorption heat exchanger hardware. Much of this hardware was previously reported in the literature, but without detailed thermal mass data. The data reported in this work are the first values reported in the literature to thoroughly account for all thermal masses, including heat transfer fluid. The impact of thermal mass on system performance is also discussed, with detailed calculation left for future work. The degree to which heat transfer fluid contributes to overall effective thermal mass is also discussed, with detailed calculation left for future work. This work provides a framework for future reporting of experimental thermal masses. The utilization of this framework will enrich the data available for model validation and provide a more thorough accounting of adsorption heat pumps. © 2020 by the authors.

  • 9.
    Guezgouz, M.
    et al.
    Mostaganem University, Algeria.
    Jurasz, Jakub
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. AGH University of Science and Technology, Cracow, Poland.
    Bekkouche, B.
    Mostaganem University, Algeria.
    Techno-economic and environmental analysis of a hybrid PV-WT-PSH/BB standalone system supplying various loads2019In: Energies, E-ISSN 1996-1073, Vol. 12, no 3, article id 514Article in journal (Refereed)
    Abstract [en]

    The Algerian power system is currently dominated by conventional (gas- and oil-fueled) power stations. A small portion of the electrical demand is covered by renewable energy sources. This work is intended to analyze two configurations of renewables-based hybrid (solar–wind) power stations. One configuration was equipped with batteries and the second with pumped-storage hydroelectricity as two means of overcoming: the stochastic nature of the two renewable generators and resulting mismatch between demand and supply. To perform this analysis, real hourly load data for eight different electricity consumers were obtained for the area of Mostaganem. The configuration of hybrid power stations was determined for a bi-objective optimization problem (minimization of electricity cost and maximization of reliability) based on a multi-objective grey-wolf optimizer. The results of this analysis indicate that, in the case of Algeria, renewables-based power generation is still more expensive than electricity produced from the national grid. However, using renewables reduces the overall CO 2 emissions up to 9.3 times compared to the current emissions from the Algerian power system. Further analysis shows that the system performance may benefit from load aggregation. 

  • 10.
    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.

  • 11.
    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%.

  • 12.
    Lundström, Lukas
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Akander, J.
    Department of Building Engineering, Energy Systems and Sustainability Science, University of Gävle, Gävle, Sweden.
    Bayesian calibration with augmented stochastic state-space models of district-heated multifamily buildings2020In: Energies, E-ISSN 1996-1073, Vol. 13, no 1, article id 76Article in journal (Refereed)
    Abstract [en]

    Reliable energy models are needed to determine building energy performance. Relatively detailed energy models can be auto-generated based on 3D shape representations of existing buildings. However, parameters describing thermal performance of the building fabric, the technical systems, and occupant behavior are usually not readily available. Calibration with on-site measurements is needed to obtain reliable energy models that can offer insight into buildings' actual energy performances. Here, we present an energy model that is suitable for district-heated multifamily buildings, based on a 14-node thermal network implementation of the ISO 52016-1:2017 standard. To better account for modeling approximations and noisy inputs, the model is converted to a stochastic state-space model and augmented with four additional disturbance state variables. Uncertainty models are developed for the inputs solar heat gains, internal heat gains, and domestic hot water use. An iterated extended Kalman filtering algorithm is employed to enable nonlinear state estimation. A Bayesian calibration procedure is employed to enable assessment of parameter uncertainty and incorporation of regulating prior knowledge. A case study is presented to evaluate the performance of the developed framework: parameter estimation with both dynamic Hamiltonian Monte Carlo sampling and penalized maximum likelihood estimation, the behavior of the filtering algorithm, the impact of different commonly occurring data sources for domestic hot water use, and the impact of indoor air temperature readings. 

  • 13.
    Lundström, Lukas
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Eskilstuna Kommunfastighet AB, Eskilstuna, Sweden.
    Akander, J.
    Division of Building, Energy and Environment Technology, Department of Technology and Environment, University of Gävle, Sweden.
    Zambrano, Jesus
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Development of a space heating model suitable for the automated model generation of existing multifamily buildings—a case study in Nordic climate2019In: Energies, E-ISSN 1996-1073, Vol. 12, no 3, article id 485Article in journal (Refereed)
    Abstract [en]

    Building energy performance modeling is essential for energy planning, management, and efficiency. This paper presents a space heating model suitable for auto-generating baseline models of existing multifamily buildings. Required data and parameter input are kept within such a level of detail that baseline models can be auto-generated from, and calibrated by, publicly accessible data sources. The proposed modeling framework consists of a thermal network, a typical hydronic radiator heating system, a simulation procedure, and data handling procedures. The thermal network is a lumped and simplified version of the ISO 52016-1:2017 standard. The data handling consists of procedures to acquire and make use of satellite-based solar radiation data, meteorological reanalysis data (air temperature, ground temperature, wind, albedo, and thermal radiation), and pre-processing procedures of boundary conditions to account for impact from shading objects, window blinds, wind- and stack-driven air leakage, and variable exterior surface heat transfer coefficients. The proposed model was compared with simulations conducted with the detailed building energy simulation software IDA ICE. The results show that the proposed model is able to accurately reproduce hourly energy use for space heating, indoor temperature, and operative temperature patterns obtained from the IDA ICE simulations. Thus, the proposed model can be expected to be able to model space heating, provided by hydronic heating systems, of existing buildings to a similar degree of confidence as established simulation software. Compared to IDA ICE, the developed model required one-thousandth of computation time for a full-year simulation of building model consisting of a single thermal zone. The fast computation time enables the use of the developed model for computation time sensitive applications, such as Monte-Carlo-based calibration methods. 

  • 14.
    Martínez-Ortega, José-Fernán
    et al.
    Technical University of Madrid.
    Rodríguez-Molina, Jesús
    Technical University of Madrid.
    Castillejo, Pedro
    Technical University of Madrid.
    de Diego, Rubén
    Technical University of Madrid.
    Middleware Architectures for the Smart Grid: Survey and Challenges in the Foreseeable Future2013In: Energies, E-ISSN 1996-1073, Vol. 6, no 7, p. 3593-3621Article in journal (Refereed)
    Abstract [en]

    The traditional power grid is just a one-way supplier that gets no feedback data about the energy delivered, what tariffs could be the most suitable ones forcustomers, the shifting daily needs of electricity in a facility, etc. Therefore, it is only natural that efforts are being invested in improving power grid behavior and turning it into a Smart Grid. However, to this end, several components have to be either upgraded or created from scratch. Among the new components required,middleware appears as a critical one, for it will abstract all the diversity of the used devices for power transmission (smart meters, embedded systems, etc.) and will provide the application layer with a homogeneous interface involving power production and consumption management data that were not able to be provided before. Additionally, middleware is expected to guarantee that updates to the current metering infrastructure (changes in service or hardware availability) or any added legacy measuring appliance will get acknowledged for any future request. Finally, semantic features are of major importance to tackle scalability and interoperability issues. A survey on the most prominent middleware architectures for Smart Grids is presented in this paper, along with an evaluation of their features and their strong points and weaknesses.

  • 15.
    Monghasemi, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Vadiee, Amir
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Jalilzadehazhari, E.
    Division of Civil Engineering and Built Environment, Department of Civil and Industrial Engineering, Uppsala University, Uppsala, 75104, Sweden.
    Rank-Based Assessment of Grid-Connected Rooftop Solar Panel Deployments Considering Scenarios for a Postponed Installation2023In: Energies, E-ISSN 1996-1073, Vol. 16, no 21, article id 7335Article in journal (Refereed)
    Abstract [en]

    Installing solar photovoltaic panels on building rooftops can help property managers generate renewable energy and reduce electricity costs. However, the existence of multiple efficiency indicators and ambiguity in interpreting these metrics limits the comparison of the performance of individual installation projects. This paper presents a methodology using data envelopment analysis to evaluate suitable candidates for rooftop solar panel installation. This approach integrates rooftop area, solar irradiation, temperature, costs, energy yield, and revenue to evaluate the relative efficiency of each building. To demonstrate the methodology, it was applied to rank 22 residential buildings, revealing the top performers for installation in 2022. The approach was subsequently adapted to assess potential outcomes under deferred implementation up to 2030, encompassing a diverse range of climate and pricing scenarios. Five installations were found to be optimal irrespective of the future scenarios. In addition, a super-efficiency approach was applied to overcome the low level of discrimination among the possible installations and to rank each individual unit uniquely. The analysis is designed to guide property owners in identifying favorable solar photovoltaic investments within their portfolios under changing conditions. 

  • 16.
    Pettinari, Matteo
    et al.
    Department of Energy, Systems, Territory and Construction Engineering, University of Pisa, Pisa, 56122, Italy.
    Frate, Guido Francesco
    Department of Energy, Systems, Territory and Construction Engineering, University of Pisa, Pisa, 56122, Italy.
    Tran, A. Phong
    Institute of Low-Carbon Industrial Processes, German Aerospace Center (DLR), 03046 Cottbus, Germany.
    Oehler, Johannes
    Institute of Low-Carbon Industrial Processes, German Aerospace Center (DLR), 03046 Cottbus, Germany.
    Stathopoulos, Panagiotis
    Institute of Low-Carbon Industrial Processes, German Aerospace Center (DLR)The institution will open in a new tab, Cottbus, 03046, Germany.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Ferrari, Lorenzo
    Department of Energy, Systems, Territory and Construction Engineering, University of Pisa, Pisa, 56122, Italy.
    Impact of the Regulation Strategy on the Transient Behavior of a Brayton Heat Pump2024In: Energies, E-ISSN 1996-1073, Vol. 17, no 5, article id 1020Article in journal (Refereed)
    Abstract [en]

    High-temperature heat pumps are a key technology for enabling the complete integration of renewables into the power grid. Although these systems may come with several variants, Brayton heat pumps are gaining more and more interest because of the higher heat sink temperatures and the potential to leverage already existing components in the industry. Because these systems utilize renewable electricity to supply high-temperature heat, they are particularly suited for industry or energy storage applications, thus prompting the development of various demonstration plants to evaluate their performance and flexibility. Adapting to varying load conditions and swiftly responding to load adjustments represent crucial aspects for advancing such systems. In this context, this study delves into assessing the transient capabilities of Brayton heat pumps during thermal load management. A transient model of an emerging prototype is presented, comprising thermal and volume dynamics of the components. Furthermore, two reference scenarios are examined to assess the transient performance of the system, namely a thermal load alteration due to an abrupt change in the desired heat sink temperature and, secondly, to a sudden variation in the sink mass flow rate. Finally, two control methodologies—motor/compressor speed variation and fluid inventory control—are analyzed in the latter scenario, and a comparative analysis of their effectiveness is discussed. Results indicate that varying the compressor speed allows for a response time in the 8–20 min range for heat sink temperature regulation (first scenario). However, the regulation time is conditioned by the maximum thermal stress sustained by the heat exchangers. In the latter scenario, regulating the compressor speed shows a faster response time than the inventory control (2–5 min vs. 15 min). However, the inventory approach provides higher COPs in part-load conditions and better stability during the transient phase.

  • 17. Rui, Xiong
    et al.
    Li, Hailong
    Mälardalen University, School of Innovation, Design and Engineering. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Xuan, Zhou
    Advanced Energy Storage Technologies and Their Applications (AESA2017)2017In: Energies, E-ISSN 1996-1073, Vol. 10, no 9Article in journal (Other academic)
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  • 18.
    Salman, Chaudhary Awais
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Omer, Ch Bilal
    Kot Addu Power Company Limited (KAPCO), Pakistan.
    Process Modelling and Simulation of Waste Gasification-Based Flexible Polygeneration Facilities for Power, Heat and Biofuels Production2020In: Energies, E-ISSN 1996-1073, Vol. 13, no 16Article in journal (Refereed)
    Abstract [en]

    There is increasing interest in the harnessing of energy from waste owing to the increase in global waste generation and inadequate currently implemented waste disposal practices, such as composting, landfilling or dumping. The purpose of this study is to provide a modelling and simulation framework to analyze the technical potential of treating municipal solid waste (MSW) and refuse-derived fuel (RDF) for the polygeneration of biofuels along with district heating (DH) and power. A flexible waste gasification polygeneration facility is proposed in this study. Two types of waste—MSW and RDF—are used as feedstock for the polygeneration process. Three different gasifiers—the entrained flow gasifier (EFG), circulating fluidized bed gasifier (CFBG) and dual fluidized bed gasifier (DFBG)—are compared. The polygeneration process is designed to produce DH, power and biofuels (methane, methanol/dimethyl ether, gasoline or diesel and ammonia). Aspen Plus is used for the modelling and simulation of the polygeneration processes. Four cases with different combinations of DH, power and biofuels are assessed. The EFG shows higher energy efficiency when the polygeneration process provides DH alongside power and biofuels, whereas the DFBG and CFBG show higher efficiency when only power and biofuels are produced. RDF waste shows higher efficiency as feedstock than MSW in polygeneration process.

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  • 19.
    Soibam, Jerol
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Rabhi, Achref
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    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.
    Bel Fdhila, Rebei
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Derivation and Uncertainty Quantification of a Data-Driven Subcooled Boiling Model2020In: Energies, E-ISSN 1996-1073, Vol. 13, no 22, article id 5987Article in journal (Refereed)
    Abstract [en]

    Subcooled flow boiling occurs in many industrial applications where enormous heat transfer is needed. Boiling is a complex physical process that involves phase change, two-phase flow, and interactions between heated surfaces and fluids. In general, boiling heat transfer is usually predicted by empirical or semiempirical models, which are horizontal to uncertainty. In this work, a data-driven method based on artificial neural networks has been implemented to study the heat transfer behavior of a subcooled boiling model. The proposed method considers the near local flow behavior to predict wall temperature and void fraction of a subcooled minichannel. The input of the network consists of pressure gradients, momentum convection, energy convection, turbulent viscosity, liquid and gas velocities, and surface information. The outputs of the models are based on the quantities of interest in a boiling system wall temperature and void fraction. To train the network, high-fidelity simulations based on the Eulerian two-fluid approach are carried out for varying heat flux and inlet velocity in the minichannel. Two classes of the deep learning model have been investigated for this work. The first one focuses on predicting the deterministic value of the quantities of interest. The second one focuses on predicting the uncertainty present in the deep learning model while estimating the quantities of interest. Deep ensemble and Monte Carlo Dropout methods are close representatives of maximum likelihood and Bayesian inference approach respectively, and they are used to derive the uncertainty present in the model. The results of this study prove that the models used here are capable of predicting the quantities of interest accurately and are capable of estimating the uncertainty present. The models are capable of accurately reproducing the physics on unseen data and show the degree of uncertainty when there is a shift of physics in the boiling regime.

  • 20.
    Swing Gustafsson, Moa
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Dalarna University, Sweden.
    Myhren, J. A.
    Dalarna University, Sweden.
    Dotzauer, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Gustafsson, M.
    Linköping University, Sweden.
    Life cycle cost of building energy renovation measures, considering future energy production scenarios2019In: Energies, E-ISSN 1996-1073, Vol. 12, no 14, article id 2719Article in journal (Refereed)
    Abstract [en]

    A common way of calculating the life cycle cost (LCC) of building renovation measures is to approach it from the building side, where the energy system is considered by calculating the savings in the form of less bought energy. In this study a wider perspective is introduced. The LCC for three different energy renovation measures, mechanical ventilation with heat recovery and two different heat pump systems, are compared to a reference case, a building connected to the district heating system. The energy system supplying the building is assumed to be 100% renewable, where eight different future scenarios are considered. The LCC is calculated as the total cost for the renovation measures and the energy systems. All renovation measures result in a lower district heating demand, at the expense of an increased electricity demand. All renovation measures also result in an increased LCC, compared to the reference building. When aiming for a transformation towards a 100% renewable system in the future, this study shows the importance of having a system perspective, and also taking possible future production scenarios into consideration when evaluating building renovation measures that are carried out today, but will last for several years, in which the energy production system, hopefully, will change.

  • 21.
    Swing Gustafsson, Moa
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Myhren, Jonn Are
    Högskolan Dalarna, Akademin Industri och samhälle, Byggteknik.
    Dotzauer, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Life Cycle Cost of Heat Supply to Areas with Detached Houses: A Comparison of District Heating and Heat Pumps from an Energy System Perspective2018In: Energies, E-ISSN 1996-1073, Vol. 11, no 12, article id 3266Article in journal (Refereed)
    Abstract [en]

    There are different views on whether district heating (DH) or heat pumps (HPs) is or are the best heating solution in order to reach a 100% renewable energy system. This article investigates the economic perspective, by calculating and comparing the energy system life cycle cost (LCC) for the two solutions in areas with detached houses. The LCC is calculated using Monte Carlo simulation, where all input data is varied according to predefined probability distributions. In addition to the parameter variations, 16 different scenarios are evaluated regarding the main fuel for the DH, the percentage of combined heat and power (CHP), the DH temperature level, and the type of electrical backup power. Although HP is the case with the lowest LCC for most of the scenarios, there are alternatives for each scenario in which either HP or DH has the lowest LCC. In alternative scenarios with additional electricity transmission costs, and a marginal cost perspective regarding the CHP investment, DH has the lowest LCC overall, taking into account all scenarios. The study concludes that the decision based on energy system economy on whether DH should expand into areas with detached houses must take local conditions into consideration.

  • 22.
    Tao, Jun
    et al.
    NCEPU, China.
    Zhao, Leiqiang
    NCEPU, China.
    Dong, Changqing
    NCEPU, China.
    Lu, Qiang
    NCEPU, China.
    Du, Xiaoze
    NCEPU, China.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Catalytic Steam Reforming of Toluene as a Model Compound of Biomass Gasification Tar Using Ni-CeO2/SBA-15 Catalysts2013In: Energies, E-ISSN 1996-1073, Vol. 7, no 6, p. 3284-3296Article in journal (Refereed)
    Abstract [en]

    Nickelsupported on SBA-15 doped with CeO2 catalysts (Ni-CeO2/SBA-15)was prepared, and used for steam reforming of toluene which was selected as amodel compound of biomass gasification tar. A fixed-bed lab-scale set wasdesigned and employed to evaluate the catalytic performances of the Ni-CeO2/SBA-15catalysts. Experiments were performed to reveal the effects of several factorson the toluene conversion and product gas composition, including the reactiontemperature, steam/carbon (S/C) ratio, and CeO2 loading content.Moreover, the catalysts were subjected to analysis of their carbon contentsafter the steam reforming experiments, as well as to test the catalyticstability over a long experimental period. The results indicated that theNi-CeO2/SBA-15 catalysts exhibited promising capabilities on thetoluene conversion, anti-coke deposition and catalytic stability. The toluene conversionreached as high as 98.9% at steam reforming temperature of 850 °C and S/C ratioof 3 using the Ni-CeO2(3wt%)/SBA-15 catalyst. Negligible cokeformation was detected on the used catalyst. The gaseous products mainlyconsisted of H2 and CO, together with a little CO2

  • 23.
    Thygesen, Richard
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    An Analysis of Different Solar-Assisted Heating Systems and Their Effect on the Energy Performance of Multifamily Buildings—A Swedish Case2017In: Energies, E-ISSN 1996-1073, Vol. 10, no 1, article id 88Article in journal (Refereed)
    Abstract [en]

    Today, the household sector in the European Union and in Sweden accounts for approximately 25% and 22% of the final energy demand, respectively, and the sector will continue to grow in the next decades. To limit the impact on the energy demand of buildings, the European Union has introduced the Energy Performance of Building Directive. In Sweden, a proposal for building regulations adapted to the Energy Performance of Buildings Directive has been released, but no decision on implementation of it has been made. In this article, a real building is simulated to evaluate how different combinations of heating and decentralized energy generation systems are affecting the specific energy demand of the building. Also, an analysis on how the Swedish incentive schemes affect the choice of decentralized energy generation systems is conducted. Furthermore, it is investigated if it is necessary to adopt the incentive schemes to steer towards systems that reduce the specific energy demand of the building. The conclusion in this article is that the current incentive system is ineffective in terms of specific energy demand reduction of buildings. It needs to be adapted so it steers towards a reduction of the specific energy demand of buildings.

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  • 24.
    Usman, M.
    et al.
    Department of Mechanical Engineering, University of Engineering and Technology, GT Road, Lahore, 54890, Pakistan.
    Jamil, M. K.
    Department of Mechanical Engineering, University of Engineering and Technology, GT Road, Lahore, 54890, Pakistan.
    Riaz, F.
    Department of Mechanical Engineering, University of Engineering and Technology, GT Road, Lahore, 54890, Pakistan.
    Hussain, H.
    Department of Mechanical Engineering, University of Engineering and Technology, GT Road, Lahore, 54890, Pakistan.
    Hussain, G.
    Institute of Environmental Engineering and Research, University of Engineering and Technology, GT Road, Lahore, 54890, Pakistan.
    Shah, M. H.
    Department of Mechanical Engineering, University of Engineering and Technology, GT Road, Lahore, 54890, Pakistan.
    Qyyum, M. A.
    School of Chemical Engineering, Yeungnam University, Gyeongsan, 712-749, South Korea.
    Salman, Chaudhary Awais
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Lee, M.
    School of Chemical Engineering, Yeungnam University, Gyeongsan, 712-749, South Korea.
    Refining and reuse of waste lube oil in si engines: A novel approach for a sustainable environment2021In: Energies, E-ISSN 1996-1073, Vol. 14, no 10, article id 2937Article in journal (Refereed)
    Abstract [en]

    The protection of the environment and pollution control are issues of paramount impor-tance. Researchers today are engrossed in mitigating the harmful impacts of petroleum waste on the environment. Lubricating oils, which are essential for the smooth operation of engines, are often disposed of improperly after completing their life. In the experimental work presented in this paper, deteriorated engine oil was regenerated using the acid treatment method and was reused in the engine. The comparison of the properties of reused oil, the engine’s performance, and the emissions from the engine are presented. The reuse of regenerated oil, the evaluation of performance, and emissions establish the usefulness of the regeneration of waste lubricating oil. For the used oil, total acid number (TAN), specific gravity, flash point, ash content, and kinematic viscosity changed by 60.7%, 6.7%, 4.4%, 96%, and 15.5%, respectively, compared with fresh oil. The regeneration partially restored all the lost lubricating oil properties. The performance parameters, brake power (BP), brake specific fuel consumption (BSFC), and exhaust gas temperature (EGT) improved with regenerated oil in use compared with used oil. The emissions CO and NOX contents for acid-treated oil were 9.7% and 17.3% less in comparison with used oil, respectively. Thus, regenerated oil showed improved performance and oil properties along with significantly reduced emissions when employed in an SI engine. 

  • 25.
    Wang, Y.
    et al.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Nian, V.
    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.
    Yuan, J.
    China Institute of FTZ Supply Chain, Shanghai Maritime University, Shanghai, China.
    Life cycle analysis of integrated gasification combined cycle power generation in the context of Southeast Asia2018In: Energies, E-ISSN 1996-1073, Vol. 11, no 6, article id en11061587Article in journal (Refereed)
    Abstract [en]

    Coal remains a major source of electricity production even under the current state of developments in climate policies due to national energy priorities. Coal remains the most attractive option, especially to the developing economies in Southeast Asia, due to its abundance and affordability in the region, despite the heavily polluting nature of this energy source. Gasification of coal running on an integration gasification combined cycle (IGCC) power generation with carbon capture and storage (CCS) represents an option to reduce the environmental impacts of power generation from coal, but the decarbonization potential and suitability of IGCC in the context of Southeast Asia remain unclear. Using Singapore as an example, this paper presents a study on the life cycle analysis (LCA) of IGCC power generation with and without CCS based on a generic process-driven analysis method. We further evaluate the suitability of IGCC with and without CCS as an option to address the energy and climate objectives for the developing economies in Southeast Asia. Findings suggest that the current IGCC technology is a much less attractive option in the context of Southeast Asia when compared to other available power generation technologies, such as solar photovoltaic systems, coal with CCS, and potentially nuclear power technologies.

  • 26.
    Yang, C.
    et al.
    Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Ministry of Education of China, Chongqing University, China.
    Sun, L.
    Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Ministry of Education of China, Chongqing University, China.
    Chen, Hao
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thermodynamics Analysis of a Novel Compressed Air Energy Storage System Combined with Solid Oxide Fuel Cell–Micro Gas Turbine and Using Low-Grade Waste Heat as Heat Source2023In: Energies, E-ISSN 1996-1073, Vol. 16, no 19, article id 7010Article in journal (Refereed)
    Abstract [en]

    As the next generation of advanced adiabatic compressed air energy storage systems is being developed, designing a novel integrated system is essential for its successful adaptation in the various grid load demands. This study proposes a novel design framework for a hybrid energy system comprising a CAES system, gas turbine, and high-temperature solid oxide fuel cells, aiming for power generation and energy storage solutions. The overall model of the hybrid power generation system was constructed in Aspen PlusTM, and the mass balance, energy balance, and thermodynamic properties of the thermal system were simulated and analyzed. The results demonstrate that the hybrid system utilizes the functional complementarity of CAES and solid oxide fuel cells (SOFCs), resulting in the cascade utilization of energy, a flexible operation mode, and increased efficiency. The overall round-trip efficiency of the system is 63%, and the overall exergy efficiency is 67%, with a design net power output of 12.5 MW. Additionally, thermodynamic analysis shows that it is advisable to operate the system under lower ambient temperatures of 25 °C, higher compressor and turbine isentropic efficiencies of 0.9, a higher fuel utilization of 0.62, and optimal SOFC/MGT split air flow rates of 1.1 kg/s. The results of this article provide guidance for designing innovative hybrid systems and system optimization.

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