| 1. |
- Wang, F., et al.
(författare)
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Optimal design and operation of hybrid renewable energy system for drinking water treatment
- 2021
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Ingår i: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 219
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Tidskriftsartikel (refereegranskat)abstract
- The industrial process of drinking water treatment requires intensive energy, leading to high enterprise costs and abundant carbon emissions. To ensure cost-effective and low polluting power supply for the above process, this paper proposes to deploy the grid-connected hybrid renewable system. A multi-objective nonlinear dynamic model mixed with integer variables is established for the decision makers, in which both system configurations and operations as well as benefits trade-offs from four dimensions are simultaneously considered. The ε-constraint method and system planner attitude parameters are introduced to transform the proposed model into its equivalent single objective form, which is further been solved by the LINGO software. A case study in China is given to assess the viability of the proposed model, in which optimal system configuration, economically feasible self-sufficiency ratio and optimal energy balance are obtained. Influences of electricity pricing strategies and natural resource changes on the systems are also analyzed and compared. It is found that the deployment of grid-connected hybrid wind/PV/storage system can help power users to cope with the future electricity price variation risks, with the feasible self-sufficiency ratio reaching 95%.
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| 2. |
- Xu, J., et al.
(författare)
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Energy-water nexus analysis of wastewater treatment plants (WWTPs) in China based on statistical methodologies
- 2018
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Ingår i: CLEANER ENERGY FOR CLEANER CITIES. - : Elsevier. ; , s. 259-264, s. 259-264
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Konferensbidrag (refereegranskat)abstract
- Wastewater treatment plants (WWTPs) are considered as energy-intensive facilities. Against the background of stricter policy requirements and discharge standard, thousands of municipal WWTPs are experiencing upgrading and reconstruction in China. However, the accompanying energy consumption cannot be ignored. Based on the statistical analysis of energy consumption and relevant factors from data of more than six thousand WWTPs over China, in this paper we analyzed the most influential factors related to energy consumption, which include treatment technology, wastewater amount, removed pollutants, social and economic characteristics, etc. Furthermore, we set up systematic method of energy performance assessment for WWTPs and explored the potential of energy saving in WWTPs. Results showed that processing capacity, organic pollutant concentration, discharge standard and economic factors have major effects on energy efficiency. Although sludge treatment and disposal normally consume intensive energy, it is possible to recover energy from biomass in the sludge. The results indicate that there is huge potential for energy saving and recovery in WWTPs, and we propose a conceptual roadmap for energy efficiency improving in WWTPs in China.
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| 3. |
- Gao, Y., et al.
(författare)
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Cooling pitch cabinets in wind turbines using a pulsating heat pipe : A case study
- 2023
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Ingår i: Case Studies in Thermal Engineering. - : Elsevier Ltd. - 2214-157X. ; 50
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Tidskriftsartikel (refereegranskat)abstract
- As the electric capacity of wind turbine increases, heat dissipation in pitch cabinets becomes challenging owing to the limited space and rotating conditions. To cool down the pitch cabinet more effectively and allow heat dissipation, we designed and implemented a pulsating heat pipe (PHP) in this study. We designed PHP parameters and conducted performance tests to compare the cooling performance of the fabricated PHP with that of an air-based cooling system in a 1.5 MW wind turbine. The results demonstrated steady PHP operation under rotating conditions (17.3 rpm). At a heat load of 1000 W, the evaporator outlet temperature was only 76.1 °C. However, increasing the ambient temperature adversely affected PHP operation, resulting in higher temperature and thermal resistance. The heat-pipe-based cooling system lowered the insulated gate bipolar transistor (IGBT) temperature by about 20.4 °C in relation to the air-based cooling system, while being suitable under varied conditions. Additionally, the system could successfully operate when the heat load of IGBT was 2350 W, corresponding to a 7 MW electric capacity of the wind turbine. Reducing the manufacturing cost of the heat pipe would further enhance the applicability of this system for pitch cabinet IGBT cooling, such as decreasing payback period.
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| 4. |
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| 5. |
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| 6. |
- Wang, Fengjuan, et al.
(författare)
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Physical–cyber–human framework‐based resilience evaluation toward urban power system: Case study from China
- 2024
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Ingår i: Risk Analysis. - : Wiley. - 0272-4332 .- 1539-6924.
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Tidskriftsartikel (refereegranskat)abstract
- Because the increased frequency, intensity, and duration of extreme weather events have significantly challenged power systems, there has been an increased interest in resilient power systems. This article establishes a multicriteria resilience evaluation framework for urban power systems from a physical-cyber-human system perspective, in which the two principal elements responsible for power system function degradation are described, the three major domains comprising urban power systems are explained, four core capacities that positively contribute to power system resilience are proposed, and 15 (11 objective and four subjective) power system resilience evaluation indicators are identified. Fuzzy hesitant judgment and a Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) aggregation method are employed to minimize the expert divergence and maximize the group consensus. A validation method is designed and a comparison with commonly applied performance-based and attributes-based evaluation methods is conducted. The applicability of the evaluation framework is verified using data from four Chinese municipalities: Shanghai, Beijing, Chongqing, and Tianjin. It was found that Shanghai's resilience was the best, and Chongqing's physical resistance disadvantages would result in the greatest difficulties in coping with extreme event disturbances. Physical, cyber, and human domain resilience enhancement strategies are given for different cities separately. This study provides a practical tool to evaluate, compare, and enhance power system resilience for governments and public utilities.
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| 7. |
- Wang, Fengjuan, et al.
(författare)
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Resilience evaluation framework towards urban power system
- 2021
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Ingår i: Energy Proceedings. - : Scanditale AB.
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Konferensbidrag (refereegranskat)abstract
- As the increased frequency, intensity and duration of extreme weather events have significantly challenged power systems, greater attention has been focused on the development of resilient power systems. Taking a physical-cyber-human system perspective, this paper establishes a multi-criteria resilience evaluation framework for urban power systems, in which two principal elements responsible for power system function degradation are described, and fifteen (eleven objective and four subjective) power system resilience evaluation indicators are identified. Fuzzy hesitant judgement and a TOPSIS aggregation method are applied for the evaluation to minimize expert divergence and maximize group consensus. The evaluation method is then applied to four Chinese municipalities: Shanghai, Beijing and Chongqing, and Tianjin. It was found that Beijing’s resilience was the best of the four but overall the urban power system resiliencies were not enough in the face of extreme event challenges.
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| 8. |
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| 9. |
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| 10. |
- Zhang, Xingjin, et al.
(författare)
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Capacity configuration of a hydro-wind-solar-storage bundling system with transmission constraints of the receiving-end power grid and its techno-economic evaluation
- 2022
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Ingår i: Energy Conversion and Management. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0196-8904 .- 1879-2227. ; 270
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Tidskriftsartikel (refereegranskat)abstract
- The hydro-wind-solar-storage bundling system plays a critical role in solving spatial and temporal mismatch problems between renewable energy resources and the electric load in China. An efficient bundling system ca-pacity configuration can improve the consumption level and reduce the renewable energy transmission cost. However, the restriction between economic feasibility and technical transmission constraints of the bundling system is not well understood. This restriction is becoming more and more obvious with the decrease of renewable energy price compensation year by year. This study compares the role of technical and economic indicators of capacity configuration, as well as the constraint relationship between electricity price and trans-mission constraints. Three screening principles of capacity configuration are proposed to reveal the techno-economic interaction. This paper explores a practical engineering case of Northwest China using a bundling system capacity configuration model. The internal rate of return is assumed as 8% for the bundling system. The results show that reducing the wind curtailment rate can effectively reduce the cost per MWh when the trans-mission guarantee rate is larger than 90%. Moreover, an integrated feed-in tariff based on market competi-tiveness is obtained if the wind curtailment rate is controlled by 5%. For example, the integrated feed-in tariff is 463.7 RMB/MWh when the wind curtailment rate is less than 5% and the transmission guarantee rate is larger than 95%. These results verify that the techno-economic interaction of the bundling system offers important theoretical support for selecting techno-economic indicators and capacity configuration.
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