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  • 101.
    Li, Y.
    et al.
    Tsinghua University, Beijing, China.
    Jin, Y.
    Tsinghua University, Beijing, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Borrion, A.
    University College London, London, United Kingdom.
    Yu, Z.
    University of Stavanger, Stavanger, Norway.
    Li, J.
    Tsinghua University, Beijing, China.
    Kinetic studies on organic degradation and its impacts on improving methane production during anaerobic digestion of food waste2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 213, s. 136-147Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Organics degradation is vital for food waste anaerobic digestion performance, however, the influence of organics degradation on biomethane production process has not been fully understood. This study aims to thoroughly investigate the organics degradation performance and identify the interaction between the reduction of organic components and methane yield based on the evaluation on 12 types of food waste. Five models (i.e. exponential, Fitzhugh, transference function, Cone and modified Gompertz models) were compared regarding the prediction of organic degradation and the results showed that the exponential model fit the experiments best, whereas kinetic parameters could not be commonly used for all situations. The exponential model was then used to study the impacts of organics reduction on the methane production and results revealed that the cumulative methane production (385–627 mL/g volatile solid) increased exponentially with the removal efficiency of volatile solids, lipids, and proteins for all feedstocks, whereas volatile solid reduction increased exponentially and linearly, respectively, with the removal efficiency of lipids and proteins. Additionally, protein degradation increased exponentially with the reduction efficiency of lipids. The experimental data and model simulation results suggested that higher methane production (530–548 mL/g volatile solid) and removal efficiency of volatile solids (65.0–67.8%), lipids (77.8–78.2%), and proteins (54.7–58.2%) could be achieved in a shorter digestion retention when carbohydrate content was higher than 47.6%, protein content lower than 24.1%, and lipid content lower than 28.3%.

  • 102.
    Li, Y.
    et al.
    Tsinghua University, Beijing, China.
    Jin, Y.
    Tsinghua University, Beijing, China.
    Li, J.
    Tsinghua University, Beijing, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yu, Z.
    University of Stavanger, Stavanger, Norway .
    Effects of thermal pretreatment on the biomethane yield and hydrolysis rate of kitchen waste2016Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 172, s. 47-58Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, batch tests were performed to evaluate the effects of different thermal pretreatment temperatures (55-160 °C) and durations (15-120 min) on the anaerobic digestion of kitchen waste (KW). Two commonly used approaches, namely the modified Gompertz model and the approach developed by Koch and Drewes, were applied to assess the effects of the different pretreatment parameters on the biomethane yield, lag time and hydrolysis rate constant via data fitting. The subsequent anaerobic digestion of KW pretreated at 55-120 °C presented greater efficiency, and longer treatment durations resulted in increased methane production and higher hydrolysis rate constants. These findings were obtained due to the lower nutrient loss observed in KW treated at lower temperature treatments compared with that found with higher temperature treatments. In general, the effects of thermal pretreatment on the lag phase and hydrolysis rate differed depending on the treatment parameters leading to the variations in the KW compositions. The soundness of the two model results was evaluated, and higher statistical indicators (R2) were found with the modified Gompertz model than with the approach developed by Koch and Drewes. 

  • 103.
    Li, Y.
    et al.
    Tsinghua University, Beijing, China .
    Jin, Y.
    School of Environment, Tsinghua University, Beijing, China.
    Li, J.
    School of Environment, Tsinghua University, Beijing, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yu, Z.
    University of Stavanger, Stavanger, Norway .
    Nie, Y.
    School of Environment, Tsinghua University, Beijing, China .
    Effects of thermal pretreatment on degradation kinetics of organics during kitchen waste anaerobic digestion2017Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 118, s. 377-386Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The influence of thermal pretreatment on degradation properties of organics in kitchen waste (KW) was investigated. The kinetics results showed that thermal pretreatment could enhance the degradation efficiency of crude protein (CP), fat, oil and grease (FOG), volatile solid (VS) and volatile fatty acids (VFA). Thermal pretreatment showed no significant difference in the final concentration of protein but could decrease the FOG degradation potential (7–36%), while increased the lag phase for degradation of protein and FOG respectively by 35–65% and 11–82% compared with untreated KW. Cumulative biogas yield increased linearly and exponentially with the removal efficiency of VS and other organics (CP and FOG) respectively. Additionally, the reduction of CP increased exponentially with FOG removal efficiency. The calculating methods of biogas yield, organics reduction and corresponding appropriate digestion retention based on FOG and CP reduction amount and pretreatment parameters were suggested.

  • 104.
    Li, Y.
    et al.
    Academy of Chinese Energy Strategy, China University of Petroleum-Beijing, Changping, Beijing 102249, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Wang, G.
    Academy of Chinese Energy Strategy, China University of Petroleum-Beijing, Changping, Beijing 102249, China.
    Liu, X.
    Academy of Chinese Energy Strategy, China University of Petroleum-Beijing, Changping, Beijing 102249, China.
    Zhang, Q.
    Academy of Chinese Energy Strategy, China University of Petroleum-Beijing, Changping, Beijing 102249, China.
    Study on the optimal deployment for Photovoltaic components recycle in China2019Ingår i: Energy Procedia, Elsevier Ltd , 2019, Vol. 158, s. 4298-4303Konferensbidrag (Refereegranskat)
    Abstract [en]

    Photovoltaic (PV) production and installation surge in recent years because of technology development and policy orientation. However, due the deadlines of subsidy set by Chinese government, most of the PV projects are carried out in a hurry and quality issues appear. Some equipment turn out to be inferiors. The demand for subsequent treatment for PV components will surge in the early future. However, the insufficiency of recycle facilities and supporting policies, lack of public focus, make it difficult. For a better planning of PV recycle, an optimization model is applied to study on the optimal deployment of PV recycle centers in China during 2040 to 2045 based on cost minimization. Transportation cost for PV modules, capital cost and operational cost for recycle center in different provinces are taken into consideration of objective functions. The result indicates that the peak of PV components recycle will arrive around 2042. At the early stage, recycle centers will be established in Zhejiang, Guangdong, and Shanxi province, considering the intensive installation and convenient transportation. The discarded PV panels will be transported to those provinces. Then, as the recycle demand surging, recycle centers will be scattered in many provinces, such as Jiangsu, Ningxia, Hebei, Inner Mongolia and so on. Most of the PV components will be recycled within the installed provinces. 

  • 105.
    Li, Y.
    et al.
    Academy of Chinese Energy Strategy, China University of Petroleum-Beijing, Changping, Beijing 102249, China.
    Zhang, Q.
    Academy of Chinese Energy Strategy, China University of Petroleum-Beijing, Changping, Beijing 102249, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Tang, Y.
    Academy of Chinese Energy Strategy, China University of Petroleum-Beijing, Changping, Beijing 102249, China.
    Liu, B.
    Academy of Chinese Energy Strategy, China University of Petroleum-Beijing, Changping, Beijing 102249, China.
    The impact of dual-credit scheme on the development of the new energy vehicle industry2019Ingår i: Energy Procedia, Elsevier Ltd , 2019, Vol. 158, s. 4311-4317Konferensbidrag (Refereegranskat)
    Abstract [en]

    In order to further promote the development of the new energy vehicle industry, Parallel Management regulation for corporate average fuel consumption and new energy vehicle credits for passenger vehicles (dual-credit scheme) have been proposed by Ministry of Industry and Information Technology in September 2017. This study attempted to investigate the impact of dual-credit scheme on the penetration of new energy vehicles and the short-term strategies of the automotive industry. For this purpose, a market analysis model is proposed based on game theory and the credit market equilibrium to quantify the effects of the credit trading mechanism. Four categories of automakers are considered. The obtained results show that: (i) The dual-credit scheme is indeed an effective policy solution that enables the expansion of the volume of NEV market. (ii) The dual-credit scheme can accelerate the elimination of outdated technologies with lower driving mileage, and it can also promote the adoption of technologies with longer driving mileage. (iii) The dual-credit scheme allows all automakers to achieve their targets in a market efficient manner. 

  • 106.
    Li, Yangyang
    et al.
    Tsinghua University.
    Jin, Yiying
    Tsinghua University.
    Borrion, Aiduan
    University College London.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Current status of food waste generation and management in China2019Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 273, s. 654-665Artikel i tidskrift (Refereegranskat)
  • 107.
    Li, Yangyang
    et al.
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.;Tsinghua Univ, Minist Educ China, Key Lab Solid Waste Management & Environm Safety, Beijing 100084, Peoples R China..
    Jin, Yiying
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.;Tsinghua Univ, Minist Educ China, Key Lab Solid Waste Management & Environm Safety, Beijing 100084, Peoples R China..
    Borrion, Aiduan
    UCL, Dept Civil Environm & Geomat Engn, London WC1E 6BT, England..
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Jinhui
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.;Tsinghua Univ, Minist Educ China, Key Lab Solid Waste Management & Environm Safety, Beijing 100084, Peoples R China..
    Effects of organic composition on mesophilic anaerobic digestion of food waste (vol 244, pg 213, 2017)2018Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 263, s. 678-678Artikel i tidskrift (Refereegranskat)
  • 108.
    Li, Yangyang
    et al.
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.;Tsinghua Univ, Minist Educ China, Key Lab Solid Waste Management & Environm Safety, Beijing 100084, Peoples R China..
    Jin, Yiying
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.;Tsinghua Univ, Minist Educ China, Key Lab Solid Waste Management & Environm Safety, Beijing 100084, Peoples R China..
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Borrion, Aiduan
    UCL, Dept Civil Environ & Geomat Eng, London WC1E 6BT, England..
    Yu, Zhixin
    Univ Stavanger, Dept Petr Engn, N-4036 Stavanger, Norway..
    Li, Jinhui
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.;Tsinghua Univ, Minist Educ China, Key Lab Solid Waste Management & Environm Safety, Beijing 100084, Peoples R China..
    Kinetic studies on organic degradation and its impacts on improving methane production during anaerobic digestion of food waste (vol 213, pg 135, 2018)2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 229, s. 1284-1284Artikel i tidskrift (Refereegranskat)
  • 109.
    Li, Yangyang
    et al.
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.
    Jin, Yiying
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.
    Li, Jinhui
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.
    Li, Hailong
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yu, Zhixin
    Universitetet i Stavanger.
    Effects of pungency degree on mesophilic anaerobic digestion of kitchen waste2016Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 181, s. 171-178Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study investigated the influence of pungency degrees (PDs) on mesophilic anaerobic digestion of kitchen waste (KW). Batch tests were performed to evaluate the methane potential and production rate and the effect of PDs on organics degradation efficiency (in terms of volatile solids, protein and ether extract) at mesophilic temperature. Koch and Drewes model and modified Gompertz model were applied to assess the effects of PDs on the hydrolysis rate constant, biomethane yield rate and lag time. The results revealed that with the increasing contributions of PDs, the methane yield, organics degradation efficiency and hydrolysis rate of KW decreased while the pH values and concentrations of total ammonia nitrogen and free ammonia nitrogen were increased. Additionally, PDs lower than PD3 presented better digestion performance, and according to results of organics degradation and kinetics study, it could be suggested that appropriate range of PD in KW beneficial for AD is PD5-PD4.

  • 110.
    Li, Yangyang
    et al.
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China..
    Jin, Yiying
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China..
    Li, Jinhui
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China..
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yu, Zhixin
    Univ Stavanger, Dept Petr Engn, N-4036 Stavanger, Norway..
    Effects of thermal pretreatment on the biomethane yield and hydrolysis rate of kitchen waste (vol 172, pg 45, 2016)2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 229, s. 1285-1285Artikel i tidskrift (Refereegranskat)
  • 111.
    Li, Yangyang
    et al.
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.;Tsinghua Univ, Minist Educ China, Key Lab Solid Waste Management & Environm Safety, Beijing 100084, Peoples R China..
    Jin, Yiying
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.;Tsinghua Univ, Minist Educ China, Key Lab Solid Waste Management & Environm Safety, Beijing 100084, Peoples R China..
    Li, Jinhui
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.;Tsinghua Univ, Minist Educ China, Key Lab Solid Waste Management & Environm Safety, Beijing 100084, Peoples R China..
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yu, Zhixin
    Univ Stavanger, Dept Petr Engn, N-4036 Stavanger, Norway..
    Nie, Yongfeng
    Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China.;Tsinghua Univ, Minist Educ China, Key Lab Solid Waste Management & Environm Safety, Beijing 100084, Peoples R China..
    Effects of thermal pretreatment on degradation kinetics of organics during kitchen waste anaerobic digestion (vol 118, pg 377, 2017)2018Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 153, s. 1089-1089Artikel i tidskrift (Refereegranskat)
  • 112.
    Lijing, Zhu
    et al.
    China Univ Petr, Acad China Energy Strategy, Peoples R China.
    Huihui, Lu
    China Univ Petr, Acad China Energy Strategy, Peoples R China.
    Qi, Zhang
    China Univ Petr, Acad China Energy Strategy, Peoples R China.
    LI, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Xunzhang, Pan
    China Univ Petr, Acad China Energy Strategy, Peoples R China.
    Ge, Wang
    China Univ Petr, Acad China Energy Strategy, Peoples R China.
    Yan, Li
    China Univ Petr, Acad China Energy Strategy, Peoples R China.
    Application of Crowdfunding on the Financing of EV's Charging Piles2016Ingår i: CLEAN ENERGY FOR CLEAN CITY: CUE 2016 - APPLIED ENERGY SYMPOSIUM AND FORUM: LOW-CARBON CITIES AND URBAN ENERGY SYSTEMS, 2016, s. 336-341Konferensbidrag (Refereegranskat)
    Abstract [en]

    The market penetration of electric vehicle is subject to the capacity of charging facility greatly, however the development of charging facility is influenced by the economic incentives. In this study, the crowdfunding method is applied for financing the construction of electric vehicle (EV) charging piles, and its advantages was focused and proved. A three-stage sequential game model was developed considering power grid, infrastructure operators and crowdfunders to analyze the performance of crowdfunding in charging pile construction. The result shows that crowdfunding can increase charging piles construction amount by 70% and crowdfunding's promoting effect equals the effect of supplying 40% subsidy for construction fee. Thus crowdfunding is a simple but efficient way to boost the penetration of charging piles.

  • 113. Lijing, Zhu
    et al.
    Qi, Zhang
    Huihui, Lu
    Li, Hailong
    Mälardalens högskola, Akademin för innovation, design och teknik. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Li
    Benjamin, McLellan
    Xunzhang, Pan
    Study on crowdfunding’s promoting effect on the expansion of electric vehicle charging piles based on game theory analysis2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 196, s. 238-248Artikel i tidskrift (Refereegranskat)
  • 114.
    Lin, H.
    et al.
    Institute of Thermal Science and Technology, Shandong University, Jinan, China.
    Fu, K.
    Institute of Thermal Science and Technology, Shandong University, Jinan, China.
    Wang, Y.
    Institute of Thermal Science and Technology, Shandong University, Jinan, China.
    Sun, Q.
    Institute of Thermal Science and Technology, Shandong University, Jinan, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Hu, Y.
    UCL, Dept Civil Environm & Geomat Engn, London, England.
    Sun, B.
    Department of Civil, Environmental & Geomatic Engineering, University College London, London, United Kingdom.
    Wennersten, R.
    Institute of Thermal Science and Technology, Shandong University, Jinan, China.
    Characteristics of electric vehicle charging demand at multiple types of location - Application of an agent-based trip chain model2019Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 188, artikel-id 116122Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper developed an agent-based trip chain model (ABTCM) to study the distribution of electric vehicles (EVs) charging demand and its dynamic characteristics, including flexibility and uncertainty, at different types of location. Key parameters affecting charging demand include charging strategies, i.e. uncontrolled charging (UC) and off-peak charging (OPC), and EV supply equipment, including three levels of charging equipment. The results indicate that the distributions of charging demand are similar as the travel patterns, featured by traffic flow at each location. A discrete peak effect was found in revealing the relation between traffic flow and charging demand, and it results in the smallest equivalent daily charging demand and peak load at public locations. EV charging and vehicle-to-grid (V2G) flexibility were examined by instantaneous adjustable power and accumulative adjustable amount of electricity. The EVs at home locations have the largest charging and V2G flexibility under the UC strategy, except for a period of regular working time. The V2G flexibility at work and public locations is generally larger than charging flexibility. Due to the fast charging application, the uncertainties of charging demand at public locations are the highest in all locations. In addition, the OPC strategy mitigates the uncertainty of charging demand. 

  • 115.
    Lin, H.
    et al.
    Institute of Thermal Science and Technology, Shandong University, Jinan,China.
    Liu, Y.
    Institute of Thermal Science and Technology, Shandong University, Jinan,China.
    Sun, Q.
    Institute of Thermal Science and Technology, Shandong University, Jinan,China.
    Xiong, R.
    Department of Vehicle Engineering, School of Mechanical Engineering, Beijing Institute of Technology, Beijing, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Wennersten, R.
    Institute of Thermal Science and Technology, Shandong University, Jinan,China.
    The impact of electric vehicle penetration and charging patterns on the management of energy hub: A multi-agent system simulation2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 230, s. 189-206Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, a multi-agent system (MAS) was developed to simulate the operation of an energy hub (EH) with different penetration rates (PRs) and various charging patterns of electric vehicle (EV). Three charging patterns, namely uncontrolled charging pattern (UCP), rapid charging pattern (RCP) and smart charging pattern (SCP), together with vehicle to grid (V2G), were simulated in the MAS. The EV penetration rates (EV-PRs), from 10% to 90% with a step of 20%, are considered in this study. Under the UCP, the peak load increases by 3.4–17.1% compared to the case without EVs, which is the reference case in this study. A main part of the increased electricity demand can be supplied by the gas turbine (GT) when the PR is lower, i.e. 71.7% under 10% PR and 37.4% under 50% PR. Under the SCP, the charging load of EVs is shifted to the valley period and thus the energy dispatch of the EH at 07:00–23:00 remain the same as that in the reference case. When V2G is considered, the electricity demand from the grid becomes the largest in all of the cases, e.g. the demand with 50% PR doubles the electricity demand in the reference case. However, the GT output decreases by 2.9–15.7% at 07:00–23:00 due to the effect of V2G. The variations in the EH's operation further raise the changes in energy cost, i.e. the electricity and cooling prices are lowered by 18.3% and 33.8% due to the availability of V2G and the heating and cooling prices increase by 3.5% and 4.3% under the UCP with the PR of 50%. Regarding the V2G capacity, near 39% of the EVs’ battery capacity can be discharged via V2G. In addition, the paper also produced a V2G potential line, which is an effective tool to provide the maximum potential of the EVs for peak shaving at any specific time.

  • 116.
    Lin, Haiyang
    et al.
    Shandong Univ, Inst Thermal Sci & Technol, Shandong, Peoples R China.
    Bian, Caiyun
    China Univ Petr, Acad Chinese Energy Strategy, Beijing, Peoples R China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Sun, Qie
    Shandong Univ, Inst Thermal Sci & Technol, Shandong, Peoples R China.
    Wennersten, Ronald
    Shandong Univ, Inst Thermal Sci & Technol, Shandong, Peoples R China.
    Optimal Siting and Sizing of Public Charging Stations in Urban Area2018Ingår i: JOINT INTERNATIONAL CONFERENCE ON ENERGY, ECOLOGY AND ENVIRONMENT ICEEE 2018 AND ELECTRIC AND INTELLIGENT VEHICLES ICEIV 2018, DESTECH PUBLICATIONS, INC , 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Electric Vehicles (EVs) have achieved a significant development because of the continuous technology revolution and policy supports in recent years, which leads to a larger demand of EV charging stations (EVCSs). Strategies about optimal siting and sizing of public EVCSs are urgently needed in order to further assist the development of EVs. This paper focus on the return of investments on EVCSs and proposes a Mixed Integer Linear Programming (MILP) model based on Geographic Information System (GIS) to identify the optimal location and size of EVCS in cities. Traffic flow data, aggregated charging profiles and land-use classifications are used as important inputs together with important constraints, are included in the MILP model with the objective function of maximizing the total profits of new charging stations. The effectiveness of the proposed method is then demonstrated by implementing a case study in Vasteras, Sweden.

  • 117.
    Liu, L.
    et al.
    Shandong University, China.
    Liu, D.
    Shandong University, China.
    Sun, Q.
    Shandong University, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Wennersten, R.
    Shandong University, China.
    Forecasting Power Output of Photovoltaic System Using A BP Network Method2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 780-786Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The characteristics of intermittent and stochastic of solar energy has brought great challenges to power grid system in terms of operation and regulation. Power forecasting is an important factor for optimal schedule of power grid system and assessing the working performance of PV systems. In order to forecast the power output of a PV system located in Ashland at 24-hour-ahead for higher efficiency, a back propagation (BP) neural network model is proposed. Before designing the model, correlation analysis is done to investigate the relationship between power output and solar irradiance and ambient temperature, which are key parameters affecting the power output of PV systems. Based on a correlation analysis, the model admitted the following input parameters: hourly solar radiation intensity, the highest, the lowest daily and the average daily temperature, and hourly power output of the PV system. The output of the model is the forecasted PV power output 24 hours ahead. Based on the datasets, the neural network is trained to improve its accuracy. The best performance is obtained with the BP neural network structure of 28-20-11. The analysis of the error indicator MAPE shows that the proposed model has great accuracy and efficiency for forecasting the power output of photovoltaic systems.

  • 118.
    Liu, L.
    et al.
    Shandong University, Jinan, China.
    Sun, Q.
    Shandong University, Jinan, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yin, H.
    Shandong University, Jinan, China.
    Ren, X.
    Shandong University, Jinan, China.
    Wennersten, R.
    Shandong University, Jinan, China.
    Evaluating the benefits of Integrating Floating Photovoltaic and Pumped Storage Power System2019Ingår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 194, s. 173-185Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Floating Photovoltaic systems have developed very fast in recent years. Compared to individual Floating Photovoltaic systems, further advantages, such as grid connectivity and energy storage, can be obtained when Floating Photovoltaic operates collaboratively with Pumped Storage Power Systems. This paper proposed an Integrated Floating Photovoltaic-Pumped Storage Power System and quantitatively assessed the potential of the integrated system in electricity generation and conservation of water and land resource. The study developed a coordinated operation model for the Integrated Floating Photovoltaic-Pumped Storage Power System, which employed a dual-objective optimization, namely to maximize the benefits of electricity generation and to minimize the energy imbalance at the same time. The dual-objective optimization was solved using the genetic algorithm method. Other benefits of the Integrated Floating Photovoltaic-Pumped Storage Power System, namely conservation of water and land resource, were also assessed. The proposed methodology was applied to a 2 GW Floating Photovoltaic farm and a 1 GW Pumped Storage Power System. Results indicated that the Integrated Floating Photovoltaic-Pumped Storage Power System has a great potential for gaining the benefits of electricity generation (9112.74 MWh in a typical sunny day averagely) and reducing energy imbalance (23.06 MW aggregately in one day). The coordinated operation provides the possibility to achieve a higher generation benefits without affecting the reliability of the grid, while the optimization method plays a key role of efficient coordination. In addition, the system would help to save 20.16 km 2 land and 19.06 million m 3 water a year due to the reduction in evaporation loss. The synthetic benefits greatly improve the economic and environmental feasibility of photovoltaic systems in reality.

  • 119.
    Liu, M.
    et al.
    School of Environmental Science and Engineering, Tianjin University, China.
    Zhu, C.
    School of Environmental Science and Engineering, Tianjin University, China.
    Zhang, H.
    School of Environmental Science and Engineering, Tianjin University, China.
    Zheng, W.
    School of Environmental Science and Engineering, Tianjin University, China.
    You, S.
    School of Environmental Science and Engineering, Tianjin University, China.
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. KTH.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    The environment and energy consumption of a subway tunnel by the influence of piston wind2019Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 246, s. 11-23Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the flourishing development of the subway construction, it becomes increasingly urgent to improve the subway tunnel environment and reduce the energy consumption of the tunnel ventilation system. The tunnel environment is significantly affected by the piston wind, which is influenced by the train speed. In this paper, a three-dimensional computational model of a subway tunnel is developed and validated through experiments. The model is used to study the carbon dioxide concentration and thermal environment of the subway tunnel. The optimal train speed is proposed with the aim to minimize the volume of mechanical supply air and to optimize the carbon dioxide concentration and thermal environment of the tunnel. In parallel with the considerations of tunnel environment, the subways in 25 cities of China are analyzed to study the energy conservation of the tunnel ventilation system by making full use of piston wind. The results indicate that the optimal train speed is 30 m/s based on the carbon dioxide concentration and thermal environment. The effective utilization of the piston wind can reduce 13%∼32% of the energy consumption for tunnel ventilation. The calculation method of the optimal train speed developed in this paper is also applicable to ordinary railway tunnels and high-speed railway tunnels.

  • 120.
    Liu, S.
    et al.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, China.
    Lu, F.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, China.
    Dai, B.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, China.
    Nian, V.
    Energy Studies Institute, National University of Singapore, Singapore.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Qi, H.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, China.
    Li, J.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, China.
    Performance analysis of two-stage compression transcritical CO2 refrigeration system with R290 mechanical subcooling unit2019Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 189, artikel-id 116143Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The use of carbon dioxide (CO2) as refrigerant is driven by the need to phase down the traditional synthetic refrigerant so as to mitigate the warming climate. In this study, the thermal performance of a two-stage compression transcritical CO2 refrigeration system with R290 mechanical subcooling unit is conducted. The goal is to obtain the maximum coefficient of performance (COP) of five different mechanical subcooling systems under the optimal subcooling temperature and compressor discharge pressure. The two-throttling and two-stage compression high-pressure mechanical subcooling system is found to have a higher COP. When the evaporation temperature is −30 °C, the COP of the two-throttling and two-stage compression high-pressure mechanical subcooling system is improved by 76.74%. The COP of the two-throttling and two-stage compression high-pressure mechanical subcooling system is 1.52 at an ambient temperature of 40 °C, which is 21.87% higher than that of the two-throttling and two-stage compression low-pressure mechanical subcooling system. The power consumption ratio of one-throttling and two-stage compression low-pressure mechanical subcooling system is significantly higher than that of other systems. From a comprehensive analysis of the proposed four systems, the two-throttling and two-stage compression high-pressure mechanical subcooling system has the best performance over all other systems. 

  • 121.
    Liu, S.
    et al.
    Tianjin University of Commerce, China.
    Sun, Z.
    Tianjin University of Commerce, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Dai, B.
    Tianjin University of Commerce, China.
    Chen, Y.
    R&D Center, VECK (Tianjin) Co. Ltd, Tianjin, China.
    Thermodynamic analysis of CO2 transcritical two-stage compression refrigeration cycle systems with expanders2017Ingår i: HKIE Transactions Hong Kong Institution of Engineers, ISSN 1023-697X, Vol. 24, nr 2, s. 70-77Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The key to improving the efficiency of carbon dioxide (CO2) transcritical refrigeration systems is to select an appropriate two-stage compression system. In this study, the thermodynamic performance of six different CO2 transcritical two-stage refrigeration systems with expanders is compared. The design parameters are analysed to determine their respective impacts on the system coefficient of performance (COP) in order to ascertain which system configuration produces the maximum system COP. It is concluded that the system with a two-stage expander and incomplete intercooling has great advantages in terms of performance and equipment selection for the high-pressure stage in certain circumstances. Under the given conditions, the design parameters including the evaporating temperature, the condensing temperature, the compressor efficiency of the high-pressure stage, and the compressor efficiency of the low-pressure stage impact on the system performance. It should be noted that the gas cooler outlet temperature and the compressor efficiency of the low-pressure stage are the major factors which affect the efficiency of the system; thus, the system design and equipment selection should minimise the gas cooler outlet temperature and select a high-efficiency compressor for the low-pressure stage to ensure efficient and safe operation. 

  • 122.
    Liu, Shengchun
    et al.
    Tianjin University of Commerce.
    Li, Zheng
    Tianjin University of Commerce.
    Dai, Baomin
    Tianjin University of Commerce.
    Zhong, Zhifeng
    Tianjin University of Commerce.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Song, Mengjie
    Sun, Zhili
    Energetic, economic and environmental analysis of air source transcritical CO2 heat pump system for residential heating in China2019Ingår i: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 148, s. 1425-1439Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Using air source heat pump system for residential heating is a practical way to replace coal-fired boiler in China to alleviate the haze problem, and CO2 is a promising candidate to replace hydrochlorofluorocarbon (HCFC) or hydrofluorocarbon (HFCs) charged into the system. A mathematical model is developed to comprehensively evaluate the energetic, economical and environmental performances of CO2 heat pump system compared with other three traditional heating methods. The results indicate that the primary energy ratio of CO2 heat pump is the highest and it is a rational way to utilize renewable energy with the renewable energy contribution ratio of 0.60–0.69. The initial capital cost of CO2 heat pump is much higher due to the dominant compressor cost. The emission of CO2 heat pump is lower than that of coal-fired boiler at seasonal performance factor above 2.44. The initial and operation cost can be gradually reduced with the mass production and energy efficiency improvement of CO2 heat pump. It is believe that air source CO2 heat pump system can be employed for home heating in China, especial for the hot summer and cold winter region.

  • 123.
    Liu, Shengchun
    et al.
    Tianjin University of Commerce, China.
    Wu, Sicheng
    Tianjin University of Commerce, China.
    Hu, Yukun
    University College London, UK.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Comparative analysis of air and CO2 as working fluids for compressed and liquefied gas energy storage technologies2019Ingår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. feb, s. 608-620Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the large-scale use of intermittent renewable energy worldwide, such as wind energy and solar energy, energy storage systems are urgently needed and have been rapidly developed. Technologies of compressed gas energy storage (CGES) and liquefied gas energy storage (LGES) are playing an important role, and air has been commonly used as working fluid. CO2 is another potential working fluid and attracting more and more attention due to the rise of CO2 capture and utilization. However, it is still unclear which is the better working fluid. This paper comparatively analyzed the performance of CGES and LGES systems using air and CO2 as working fluids. Both diabatic and adiabatic CGES are considered. Simulation results show that except diabatic CGES systems, using CO2 could achieve a similar or even higher round-trip efficiency than using air. In addition, the use of CO2 instead of air as a working fluid has additional advantages, such as a lower storage temperature can be achieved at the same storage pressure for the adiabatic CGES system; and a higher condensing temperature can be achieved at the same condensing pressure for the LGES system, which can benefit the system design and operation.

  • 124.
    Liu, Z.
    et al.
    Qingdao University of Science and Technology, Qingdao, 266061, China.
    Yang, X.
    Xi'an Jiaotong University, Xi'an, 710049, China.
    Jia, W.
    Qingdao University of Science and Technology, Qingdao, 266061, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Justification of CO2 as the working fluid for a compressed gas energy storage system: A thermodynamic and economic study2020Ingår i: Journal of Energy Storage, E-ISSN 2352-152X, Vol. 27, artikel-id 101132Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The compressed carbon dioxide (CO2) energy storage (CCES) system has been attracting more and more attentions in recent years. The CCES system leads the way of green solutions to accommodating the intermittency of renewable power generation systems in a large-scale energy storage pattern. Particularly, the usage of CO2 as the working medium for CCES successfully offers a green solution to massive carbon capture and storage. This paper aims to further analyze the applicability and feasibility of a novel CCES system with the merit of efficiently and economically utilizing pressure energy and thermal energy. Thermodynamic and cost evaluation on the energy conversion cycle were carried out. Genetic algorithm was employed to perform multi-objective optimization on the novel energy conversion cycle with thermal energy storage towards maximizing exergy efficiency and economic profits. Results reveal that the net output power monotonously increases with turbine inlet temperature, but the unit product cost monotonously decreases with turbine inlet temperature. The multi-objective optimization recommends a 60.5% for the overall exergy efficiency and 0.23 $/kWh for the unit product cost. Moreover, scattered distribution of decision variables suggests always a higher outlet pressure for compressor. 

  • 125.
    Liu, ZY
    et al.
    Tianjin Univ.
    Zhao, Li
    Tianjin Univ.
    Zhao, Xuezheng
    Tianjin Univ.
    Li, Hailong
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    The occurrence of pinch point and its effects on the performance of high temperature heat pump2012Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 97, nr SI, s. 869-875Artikel i tidskrift (Refereegranskat)
    Abstract [en]

     Zeotropic mixtures are popular alternatives to chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) in the high temperature heat pump system. Zeotropic mixtures exhibit two major characteristics during phase change: temperature gliding and a nonlinear relationship between temperature and enthalpy. The theory proposed by Venkatarathnam that the nonlinear relationship between temperature and enthalpy in the two phase region for zeotropic mixtures can cause pinch points were verified experimentally. Results also show that the variations of the maximum temperature difference and the minimum temperature difference change the mean temperature difference in the same way, and further change the exergy loss in the same way. Therefore, when selecting zeotropic mixtures as working fluids in the high temperature heat pump, it is of great importance to check the pinch points occurring in condenser and evaporator. The zeotropic mixture that has a smaller maximum temperature difference in condenser and a smaller minimum temperature difference in evaporator can give a higher COP.

  • 126.
    Lu, F.
    et al.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin 300134, China.
    Liu, S.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin 300134, China.
    Dai, B.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin 300134, China.
    Zhong, Z.
    Foreign Economic Cooperation Office, Ministry of Ecology and Environment, Beijing 100035, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Future Energy Center, School of Sustainable Development of Society and Technology, Mälardalen University, Västerås SE-72123, Sweden; Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin 300134, China.
    Sun, Z.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin 300134, China.
    Experimental study on thermal performance of transcritical CO 2 air source heat pump for space heating2019Ingår i: Energy Procedia, Elsevier Ltd , 2019, Vol. 158, s. 5913-5919Konferensbidrag (Refereegranskat)
    Abstract [en]

    Employing transcritical CO 2 heat pump system for space heating is an effective way to solve the issue of air pollution during the heating season in China. Thus, an experimental setup is developed to study the thermal performance of the transcritical CO 2 air source heat pump system used for space heating. The test results show that a maximum coefficient of performance (COP) of 2.88 is obtained at the optimum discharge pressure and the ambient temperature of 10 o C. The optimal high pressure is nearly a constant with the value of about 8.5 MPa for the ambient temperature in the range of -15~10 o C. The system COP increases with the ambient temperature increasing, and the outlet temperature of the gas cooler is a dominant influencing factor on the thermal performance of the heat pump system. Little difference can be found between the gas cooler outlet temperatures with the variation in ambient temperatures.

  • 127.
    Lu, H.
    et al.
    School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China.
    Yu, X.
    School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Tu, S. -T
    School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China.
    Accurately measurement and efficiently recovery of ionic liquid in energy utilization of microalgae2019Ingår i: Energy Procedia, Elsevier Ltd , 2019, Vol. 158, s. 1337-1341Konferensbidrag (Refereegranskat)
    Abstract [en]

    Chlorella vulgais, a kind of micro-alagae, is an attracting feedstock for bioenergy production, such as biodiesel and biogas. But its tough cell wall structure is the main obstacle to efficiently extracting lipids and other biomass. Ionic liquid (IL) can be used to hydrolyze its cell-wall. However, due to its high cost and toxicity, it is important to recover IL as much as possible. Therefore, a method that can accurately measure the content of ILs, is urgently needed. In this work, two common methods that are used to measure the content of ILs: equimolar titration method and ultraviolet absorbance spectra were compared. The results show that equimolar titration method is not available for trace quantity analysis of ionic liquids as the endpoint of titration is hard to be identified at low IL content (<10 mg/L); while UV absorbance spectra method can be used at low IL contents, whereas, it may result in big deviations. To further improve the accuracy of UV absorbance spectra method, concentrating the sample could be a potential solution.

  • 128.
    Lu, H.
    et al.
    East China University of Science and Technology, Shanghai, China.
    Yu, X.
    East China University of Science and Technology, Shanghai, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Tu, S. -T
    East China University of Science and Technology, Shanghai, China.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lipids extraction from wet Chlorella pyrenoidosa sludge using recycled [BMIM]Cl2019Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 291, artikel-id 121819Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, experiments on pretreating one species of microalgae (Chlorella pyrenoidosa) using one kind of ionic liquid (IL) of [BMIM]Cl were conducted. The aim of this work is to evaluate the recycling efficacy of expensive IL solvent for effective cell disruption. It was indicated that the molecular structure of IL was stable during the recycling test. Five times antisolvent precipitation of microalgae debris after lipid extraction using methanol recovered 99.8% IL with the energy consumption of 4.46 MJ per kg dry Chlorella pyrenoidosa. The chromatography was used to separate IL and hydrolysates, resulting in the IL loss below 1.97 g per kg dry Chlorella pyrenoidosa. © 2019 Elsevier Ltd

  • 129.
    Luyao, Liu
    et al.
    Shandong University, Jinan, China.
    Qinxing, Wang
    Shandong University, Jinan, China.
    Haiyang, Lin
    Shandong University, Jinan, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Qie, Sun
    Shandong University, Jinan, China.
    Wennersten, Roland
    Shandong University, Jinan, China.
    Power Generation Efficiency and Prospects of Floating Photovoltaic Systems2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, s. 1136-1142Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    At present, China's economic and social development is restricted by many factors, such as environmental pollution and the supply of energy, land resources and water resources. Compared with traditional terrestrial photovoltaic (PV) systems, floating PV systems can save a lot of land and water resources and obtain higher power generation efficiency. Although the academics have reached a general consensus about the advantages of floating systems, very few in-depth studies focus on the specifications of floating PV systems. Therefore, this study first discusses the development of PV technology, then studies the power generation efficiency of floating PV systems, and finally comprehensively analyzes the advantages and potential of floating PV systems in China.

  • 130.
    Ma, Z.
    et al.
    Beijing University of Posts and Telecommunications, Beijing, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Sun, Q.
    Shandong University, Jinan, China .
    Wang, C.
    Tongji University, Shanghai, China.
    Yan, A.
    Tianjin Institute of Urban Construction, Tianjin, China .
    Starfelt, Fredrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Statistical analysis of energy consumption patterns on the heat demand of buildings in district heating systems2014Ingår i: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 85, s. 664-672Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Precise prediction of heat demand is crucial for optimising district heating (DH) systems. Energy consumption patterns (ECPs) represent a key parameter in developing a good mathematical model to predict heat demand. This study quantitatively investigated the impacts of ECPs on heat consumption. Two key factors, namely, time and type of buildings, were used to reflect various ECPs in DH systems, and a Gaussian mixture model (GMM) was developed to examine their impacts on heat consumption. The model was trained and validated using the measured data from a real DH system. Results show that the factor of time does not represent a good reflection of ECP. In contrast, categorising buildings according to their function is an effective way to reflect ECPs. Based on the defined building types, i.e., commercial, apartment and office, the average absolute deviation of the predicted heat load was about 4-8%.

  • 131.
    Ma, Z.
    et al.
    Beijing University of Posts and Telecommunications, China.
    Xie, J.
    Beijing University of Posts and Telecommunications, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Tianjin University of Commerce, China.
    Sun, Q.
    Shandong University, China.
    Si, Z.
    Beijing University of Posts and Telecommunications, China.
    Zhang, J.
    Beijing University of Posts and Telecommunications, China.
    Guo, J.
    Beijing University of Posts and Telecommunications, China.
    The role of data analysis in the development of intelligent energy networks2017Ingår i: IEEE Network, ISSN 0890-8044, E-ISSN 1558-156X, Vol. 31, nr 5, s. 88-95, artikel-id 8053484Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Data analysis plays an important role in the development of intelligent energy networks (IENs). This article reviews and discusses the application of data analysis methods for energy big data. The installation of smart energy meters has provided a huge volume of data at different time resolutions, suggesting data analysis is required for clustering, demand forecasting, energy generation optimization, energy pricing, monitoring and diagnostics. The currently adopted data analysis technologies for IENs include pattern recognition, machine learning, data mining, statistics methods, and so on. However, existing methods for data analysis cannot fully meet the requirements for processing the big data produced by IENs, therefore more comprehensive data analysis methods are needed to handle the increasing amount of data and to mine more valuable information.

  • 132.
    Ma, Z.
    et al.
    Beijing University of Posts and Telecommunications, Beijing, China.
    Xie, J
    Beijing University of Posts and Telecommunications, Beijing, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Sun, Q.
    Shandong University, 12589 Jinan, Shandong China.
    Wallin, Fredrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Si, Z
    Beijing University of Posts and Telecommunications, Beijing, China.
    Guo, J
    Beijing University of Posts and Telecommunications, Beijing, China.
    Deep Neural Network-based Impacts Analysis of Multimodal Factors on Heat Demand PredictionIngår i: IEEE Transactions on Big Data, ISSN 2372-2096Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Prediction of heat demand using artificial neural networks has attracted enormous research attention. Weather conditions, such as direct solar irradiance and wind speed, have been identified as key parameters affecting heat demand. This paper employs an Elman neural network to investigate the impacts of direct solar irradiance and wind speed on the heat demand from the perspective of the entire district heating network. Results of the overall mean absolute percentage error (MAPE) show that direct solar irradiance and wind speed have quite similar impacts. However, the involvement of direct solar irradiance can clearly reduce the maximum absolute deviation when only involving direct solar irradiance and wind speed, respectively. In addition, the simultaneous involvement of both wind speed and direct solar irradiance does not show an obvious improvement of MAPE. Moreover, the prediction accuracy can also be affected by other factors like data discontinuity and outliers.

  • 133.
    Mancuso, Martin Vincent
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Evaluation of Grid-Connected Micro-Grid Operational Strategies2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    This study investigates the operational performances of a grid-connected microgrid with integrated solar photovoltaic and battery energy storage. The study is based upon the techno-economic specifications and theoretical performance of the distributed energy resource and storage systems, as well as on measured consumer load data and electrical utility retail and distribution data for representative residential and commercial loads for the city of Västerås, Sweden. The open-source Matlab®-based simulation tool, OptiCE, is used for performing simulations and optimization. To support the attainment of one of the objectives, peak shaving of the consumer load, a battery operational strategy algorithm has been developed to balance peak shaving and PV self-consumption. Comparisons among three types of battery, lead-acid, lithium-ion and vanadium-redox flow, are also performed. A 117 kW p photovoltaic system paired with a lithium-ion battery of 41.1 kWh capacity is the optimal solution found for the considered commercial load. The calculated battery capacity represents the best trade-off for the set multi-objective optimization problem. The simulation of this system predicts the possibility to shave the customer load profile peaks up to 20% for the month of April. The corresponding self-consumption ratio is 88%. Differences in the relationship between the load profiles and the system performance have been qualitatively noted. Furthermore, the simulation results for lead-acid, lithium-ion and vanadium-redox flow battery systems reveal that lithium-ion batteries delivers the best trade-off between total annualized cost and peak shaving performance for both residential and commercial applications.

  • 134.
    Md Lokman, Hosain
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Bel Fdhila, Rebei
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Sand, U.
    Engdahl, J.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    CFD Modeling of Real Scale Slab Reheating FurnaceKonferensbidrag (Refereegranskat)
  • 135.
    Mirmoshtaghi, Guilnaz
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    BIO-METHANE PRODUCTION THROUGH DIFFERENT BIOMASS GASIFIERS2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Considering sustainability of energy resources and environmental concerns have led to activities all over the world seeking alternatives for current methods of fuel production. Gasification of biomass to supply bio-methane is one of those options. Bio-methane is carbon neutral and meets the needs of combustion engines in vehicles.Focusing on vehicle fuel production reveals the need for wide research to understand different types of gasifiers in order to find the possibilities for more methane production.In this paper data collected from different experimental setups are summarized and analyzed.Fluidized bed gasifiers show higher methane concentrations in the produced gas while entrained flow and downdraft gasifiers may be the least suitable types for high methane yields.Heating value of the product gas and cold gas efficiency are also studied as the important parameters for evaluating the characteristics of the product gas. This analysis shows that by increasing the equivalence ratio, the heating value of the product gas decreases while the efficiency may not follow the same trend.

  • 136.
    Mirmoshtaghi, Guilnaz
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Mälardalen Högskola.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    EVALUATION OF DIFFERENT BIOMASS GASIFICATION MODELING APPROACHES FOR FLUIDIZED BED GASIFIERS2016Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 91, s. 69-82Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To develop a model for biomass gasification in fluidized bed gasifiers with high accuracy and generality that could be used under various operating conditions, the equilibrium model (EM) is chosen as a general and case-independent modeling method. However, EM lacks sufficient accuracy in predicting the content (volume fraction) of four major components (H2, CO, CO2 and CH4) in product gas. In this paper, three approaches—MODEL I, which restricts equilibrium to a specific temperature (QET method); MODEL II, which uses empirical correlations for carbon, CH4, C2H2, C2H4, C2H6 and NH3 conversion; and MODEL III, which includes kinetic and hydrodynamic equations—have been studied and compared to map the barriers and complexities involved in developing an accurate and generic model for the gasification of biomass.

    This study indicates that existing empirical correlations can be further improved by considering more experimental data. The updated model features better accuracy in the prediction of product gas composition in a larger range of operating conditions. Additionally, combining the QET method with a kinetic and hydrodynamic approach results in a model that features less overall error than the original model based on a kinetic and hydrodynamic approach.

  • 137.
    Mirmoshtaghi, Guilnaz
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Mälardalen Högskola.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    THE EFFECT OF INCLUDING HYDRODYNAMICS FOR MODELING ATMOSPHERIC BUBBLING FLUIDIZED BED GASIFIERS2014Konferensbidrag (Refereegranskat)
  • 138.
    Mirmoshtaghi, Guilnaz
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Skvaril, Jan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    The influence of different parameters on biomass gasification in circulating fluidized bed gasifiers2016Ingår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 126, s. 110-123Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The mechanism of biomass gasification has been studied for decades. However, for circulating fluidized bed (CFB) gasifiers, the impacts of different parameters on the gas quality and gasifiers performance have still not been fully investigated. In this paper, different CFB gasifiers have been analyzed by multivariate analysis statistical tools to identify the hidden interrelation between operating parameters and product gas quality, the most influencing input parameters and the optimum points for operation. The results show that equivalence ratio (ER), bed material, temperature, particle size and carbon content of the biomass are the input parameters influencing the output of the gasifier the most. Investigating among the input parameters with opposite impact on product gas quality, cases with optimal gas quality can result in high tar yield and low carbon conversion while low tar yield and high carbon conversion can result in product gas with low quality. However using Olivine as the bed material and setting ER value around 0.3, steam to biomass ratio to 0.7 and using biomass with 3 mm particle size and 9 wt% moisture content can result in optimal product gas with low tar yield.

  • 139.
    Mirmoshtaghi, Guilnaz
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Mälardalen Högskola.
    Skvaril, Jan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    INVESTIGATION OF EFFECTIVE PARAMETERS ON BIOMASS GASIFICATION IN CIRCULATING FLUIDIZED BED GASIFIERS2015Konferensbidrag (Refereegranskat)
  • 140.
    Mirmoshtaghi, Guilnaz
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Skvaril, Jan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Investigation of Most Effective Parameters on Biomass Gasufication in Circulating Fluidized bed Gasifiers2015Ingår i: Forest and Plant Bioproducts Division 2015 - Core Programming Area at the 2015 AIChE Annual Meeting, 2015, s. 189-200Konferensbidrag (Refereegranskat)
  • 141.
    Mokgonyana, L.
    et al.
    University of Strathclyde, United Kingdom.
    Zhang, J.
    University of Technology Sydney, Australia.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Hu, Y.
    University of Liverpool, United Kingdom.
    Optimal location and capacity planning for distributed generation with independent power production and self-generation2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 188, s. 140-150Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper proposes a planning model for power distribution companies (DISCOs) to maximize profit. The model determines optimal network location and capacity for renewable energy source, which are categorized as independent power production (IPP) and self-generation (SG). IPP refers to generators owned by third-party investors and linked to a quota obligation mechanism. SG encompasses smaller generators, supported by feed-in tariffs, that produce energy for local consumption, exporting any surplus generation to the distribution network. The obtained optimal planning model is able to evaluate network capacity to maximize profit when the DISCO is obliged to provide network access to SG and IPP. Distinct parts of the objective function, owing to the definition of SG, are revenue erosion, recovery as well as the cost of excess energy. Together with the quota mechanism for IPP, the combination of all profit components creates a connection trade-off between IPP and SG for networks with limited capacity. The effectiveness of the model is tested on 33- and 69-bus test distribution systems and compared to standard models that maximize generation capacity with predefined capacity diffusion. Simulation results demonstrate the model outperforms the standard models in satisfying the following binding constraints: minimum IPP capacity and SG net energy. It is further revealed that integrating SG and IPP with the proposed model increases profit by up to 23.7%, adding an improvement of 8% over a feasible standard model.

  • 142.
    Nian, V.
    et al.
    Energy Studies Institute, National University of Singapore, Singapore.
    Jindal, G.
    Energy Studies Institute, National University of Singapore, Singapore.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    A feasibility study on integrating large-scale battery energy storage systems with combined cycle power generation – Setting the bottom line2019Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 185, s. 396-408Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Strong attention has been given to the costs and benefits of integrating battery energy storage systems (BESS) with intermittent renewable energy systems. What's neglected is the feasibility of integrating BESS into the existing fossil-dominated power generation system to achieve economic and environmental objectives. In response, a life cycle cost-benefit analysis method is introduced in this study taking into consideration three types of battery technologies, namely, vanadium redox flow battery, zinc bromine flow battery, and lithium-iron-phosphate battery. The objective is to evaluate the life cycle carbon emissions and cost of electricity production by combined cycle power generation with grid-connected BESS. Findings from the Singapore case study suggest a potential 3–5% reduction in the life cycle carbon emission factors which could translate to a cumulative carbon emission reduction of 9–16 million tonnes from 2018 to 2030 from electricity generation. Grid-connected BESS could reduce the levelized cost of electricity by 4–7%. A synergistic planning of CCGT and BESS could theoretically reduce the system level power generation capacity by 26% albeit a potential increase in the overall capital cost at the current cost of batteries. The projected battery cost reduction is critical in improving the feasibility of large-scale deployment. 

  • 143.
    Nian, V.
    et al.
    Energy Studies Institute, National University of Singapore, Singapore.
    Sun, Q.
    Institute of Thermal Science and Technology, Shandong University, China.
    Ma, Z.
    Beijing University of Posts and Telecommunications, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    A Comparative Cost Assessment of Energy Production from Central Heating Plant or Combined Heat and Power Plant2016Ingår i: Energy Procedia, 2016, s. 556-561Konferensbidrag (Refereegranskat)
    Abstract [en]

    The levelized cost of electricity (LCOE) is a common approach in evaluating the economic competitiveness of a power generation technology. The same approach can be applied for evaluating the levelized cost of heat (LCOH) production. There are a number of approaches in calculating the LCOE and or LCOH from a combined heat and power (CHP) plant. In this study, we explore three alternative methods in calculating the LCOE and LCOH of a CHP and compare the results with that those of a heating only plant. The results can be used as indicators for identifying a suitable pricing mechanisms for the heating market.

  • 144.
    Nookuea, Worrada
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Tan, Y.
    School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm, Sweden.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm, Sweden.
    Impacts of thermo-physical properties of gas and liquid phases on design of absorber for CO2 capture using monoethanolamine2016Ingår i: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 52, s. 190-200Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Absorption of CO2 with aqueous amines in post-combustion capture is characterized as a heat and mass transfer processes with chemical reaction, which is sensitively affected by the thermo-physical properties of fluids. In order to optimize the design of the absorber of CO2 capture process, in this paper, the impacts of thermo-physical properties on the column design were investigated. Furthermore, the property impacts on the capital cost of the absorber unit were also identified and analyzed. Results show that the gas phase density has the most significant effect on the column diameter. Underestimation of the gas phase density of 10% may result in an increase of about 6% of the column diameter. For the packing height, the liquid phase density has the most significant effect. 10% underestimation of the liquid phase density may result in an increase of 8% of the packing height. Moreover, the effect from the liquid phase viscosity is also significant. For the annual capital cost, the liquid phase density also shows the most significant effect. Underestimation of the liquid phase density of 10% leads to the cost overestimation of $1.4 million for the absorption column for a 400 MW coal-fired power plant. Therefore, the development of the flue gas density model and liquid phase density and viscosity models of the aqueous amine solution with CO2 loading should be prioritized.

  • 145.
    Nookuea, Worrada
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Tan, Yuting
    Royal Inst Technol, Stockholm, Sweden.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Sensitivity study of thermo-physical properties of gas phase on absorber design for CO2 capture using monoethanolamine2015Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, s. 2305-2310Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Absorption of CO2 with aqueous amines in post-combustion capture is characterized as mass transfer process with chemical reaction. Hydrodynamics and mass transfer in gas and liquid phases in a packed column have significant influences on absorber design especially for the design of packing height. In this paper, the sensitivity study has been conducted to investigate the impacts of gas phase density, viscosity and diffusivity on the hydrodynamics and mass transfer and further the total packing height of a countercurrent flow with random packing column, using reactive absorption process and integral rate-based models. Results show that density and diffusivity have opposite effect to viscosity. Amongst various properties, diffusivity has the most significant effect on the packing height compared to density and viscosity. Overestimation of diffusivity of 5% may result in decrease of 3.2% of packing height. Moreover, developing more accurate diffusivity model should be prioritized for more accurate absorber design. 

  • 146.
    Nookuea, Worrada
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Wang, Fu
    Tianjin University, China.
    Yang, Jie
    University of Shanghai for Science and Technology, Shanghai, China.
    Tan, Yuting
    Royal Institute of Technology, Sweden .
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yu, Xinhai
    East China University of Science and Technology, Shanghai, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Viscosity data of aqueous MDEA–[Bmim][BF4] solutions within carbon capture operating conditions2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, s. 4581-4586Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Post–combustion capture with chemical absorption shows higher potential for commercial scale application compared with other technologies. To capture CO2 from the industrial and power plant’s flue gases, aqueous alkanolamine solutions are widely used. However, several drawbacks from utilizing the aqueous alkanolamines such as MEA still need to be solved. For example, alkanolamine solutions require intensive energy for regeneration and cause severe corrosion to the equipment though they have high reactivity in capturing CO2. Ionic liquids have been of interest in the recent development of chemical absorption according to their unique characteristics including wide liquid range, negligible volatility and thermal stability. However, due to their high price, high viscosity and low absorption capacity compared to alkanolamines, ionic liquids are still non–desirable for industrial applications.

    One possible solution to improve the performance of ionic liquids is to use mixtures of ionic liquids and alkanolamines. For a better understanding of the absorption using the mixture of aqueous alkanolamines and ionic liquids, the knowledge of thermo–physical properties of the solutions, especially the viscosity and density are of importance. This paper reports the measured viscosity of MDEA–[Bmim][BF4] aqueous mixtures at various temperatures and concentrations. It was found that the viscosity increase with an increase in [Bmim][BF4] concentration, but decrease with an increase in temperature. Moreover, the impact of temperature on the viscosity is more significant at low temperature range.

  • 147.
    Nookuea, Worrada
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zambrano, Jesús
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Tan, Yuting
    Royal Institute of Technology, Sweden.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology, Stockholm, Sweden.
    Comparison of Mass Transfer Models on Rate-Based Simulations of CO2 Absorption and Desorption Processes2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 3747-3752Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One of the keys available options for the large scale carbon capture and storage is the solvent-based post-combustion capture. Due to the high reactivity between CO2 and aqueous amine solutions, chemical absorption is suitable for capturing the CO2 at low concentration such as from the flue gas. From techno-economic analyses of the CO2 chemical absorption plant, absorber and desorber columns are the main cost of the purchased equipment. Since the process involves complex reactive separations, the accurate calculation of hydrodynamic properties, mass and energy transfer are of importance for the design of the columns. Several studies have been done on the impact of different process and property models on the equilibrium and rate-based simulation of the absorption site. However, the impact study of process and property models on the desorption site are still lacking. This paper performs rate-based simulations of CO2 absorption by Monoethanolamine. The software Aspen Plus was used for the simulations. Different mass transfer models were implemented for the mass transfer calculation in gas and liquid phases. The temperature and concentration profiles along the columns are reported and discussed.

  • 148.
    Olsson, A.
    et al.
    Royal Institute of Technology, Stockholm.
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lind, M.
    ZeroMission, Stockholm.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Potential for carbon sequestration and mitigation of climate change by irrigation of grasslands2014Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 136, s. 1145-1154Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The climate change mitigation potential of irrigation powered by a photovoltaic water pumping system (PVWPS) to restore degraded grasslands has been investigated using the Intergovernmental Panel on Climate Change (IPCC) 2006 Guidelines for National Greenhouse Gas Inventories for Agriculture, Forestry and Other Land Use. The purpose of this study is to develop a generic and simple method to estimate the climate change mitigation benefit of a PVWPS. The possibility to develop carbon credits for the carbon offset markets has also been studied comparing carbon sequestration in grasslands to other carbon sequestration projects. The soil carbon sequestration following irrigation of the grassland is calculated as an annual increase in the soil organic carbon pool.The PVWPS can also generate an excess of electricity when irrigation is not needed and the emissions reductions due to substitution of grid electricity give additional climate change mitigation potential.The results from this study show that the carbon sequestration and emissions reductions benefits per land area using a PVWPS for irrigating grasslands are comparable to other carbon sequestration options such as switching to no-till practice. Soil carbon in irrigated grasslands is increased with over 60% relative to severely degraded grasslands and if nitrogen fixing species are introduced the increase in soil organic carbon can be almost 80%. Renewable electricity generation by the PVWPS will further increase the mitigation benefit of the system with 70-90%. When applying the methodology developed in this paper to a case in Qinghai, China, we conclude that using a PVWPS to restore degraded grasslands for increased grass production and desertification control has a climate change mitigation benefit of 148Mg (1Mg=1metricton) CO2-equivalents (CO2-eq) per hectare in a cold temperate, dry climate during a 20year process of soil organic carbon sequestration and emissions reductions. Leakage due to an increase in N2O emissions from the additional biomass production and introduction of nitrogen fixing species is included in this result. The most important conclusion from our case is that if soil carbon sequestration is lower than 24Mg CO2-eq per hectare including leakage, then the climate change mitigation benefit is larger if PV is used to produce electricity for the grid.

  • 149.
    Olsson, Alexander
    et al.
    KTH Royal Inst Technology, Stockholm, Sweden.
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lind, Marten
    ZeroMission, Stockholm, Sweden.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    PV water pumping for carbon sequestration in dry land agriculture2015Ingår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 102, s. 169-179Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper suggests a novel model for analysing carbon sequestration activities in dry land agriculture considering the water-food-energy-climate nexus. The paper is based on our on-going studies on photovoltaic water pumping (PVWP) systems for irrigation of grasslands in China. Two carbon sequestration projects are analysed in terms of their water productivity and carbon sequestration potential. It is concluded that the economic water productivity, i.e. how much water that is needed to produce an amount of grass, of grassland restoration is low and that there is a need to include several of the other co-benefits to justify the use of water for climate change mitigation. The co-benefits are illustrated in a nexus model including (1) climate change mitigation, (2) water availability, (3) downstream water impact, (4) energy security, (5) food security and (6) moisture recycling. We argue for a broad approach when analysing water for carbon sequestration. The model includes energy security and food security together with local and global water concerns. This makes analyses of dry land carbon sequestration activities more relevant and accurate. Without the nexus approach, the co-benefits of grassland restoration tend to be diminished. 

  • 150.
    Prabaharan, N.
    et al.
    School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur Tamil Nadu, India.
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Jerin, A.R.A.
    School of Electrical Engineering, Vellore Institute of Technology, Vellore Tamil Nadu, India.
    Palanisamy, K.
    School of Electrical Engineering, Vellore Institute of Technology, Vellore Tamil Nadu, India.
    A new approach for grid integration of solar photovoltaic system with maximum power point tracking using multi‐output converter2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper proposes a new approach for grid integration of solar photovoltaic system using modified incremental conductance maximum power point tracking algorithm with multi-output converter and multilevel inverter. The multi-output converter is a combination of boost converter and switched capacitor function to generate different self-balanced output voltages using single switch, single inductor, 2N-1 diodes and 2N-1 capacitors. This topology is proposed to be used as DC link in applications where several controlled voltage levels are required with self-balancing and unidirectional current flow, such as photovoltaic (PV) or fuel cell generation systems with multilevel inverter. The utilization of multilevel inverter in the proposed system provides better quality of output voltage and current waveform thereby reducing the size of passive filters. Also, it eliminates the requirement of bulky transformers for grid integration. Multicarrier unipolar phase disposition pulse width modulation technique is employed for triggering the switches of the multilevel inverter. The proposed system is tested with standard test conditions using MATLAB/SIMULINK.

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