Multi-energy synergy systems integrating high-penetration large-scale plug-in electric vehicles, distributed renewable energy generations, and battery energy storage systems have great potential to reduce the reliance...Multi-energy synergy systems integrating high-penetration large-scale plug-in electric vehicles, distributed renewable energy generations, and battery energy storage systems have great potential to reduce the reliance of the grid on traditional fossil fuels. However, the random charging characteristics of plug-in electric vehicles and the uncertainty of photovoltaics may impose an additional burden on the grid and affect the supply–demand equilibrium. To address this issue, judicious scheduling optimization offers an effective solution. In this study, considering charge and discharge management of plug-in electric vehicles and intermittent photovoltaics, a novel Multi-energy synergy systems scheduling framework is developed for solving grid instability and unreliability issues. This formulates a large-scale mixed-integer problem, which calls for a powerful and effective optimizer. The new binary level-based learning optimization algorithm is proposed to address nonlinear large-scale high-coupling unit commitment problems. To investigate the feasibility of the proposed scheme, numerical experiments have been carried out considering multiple scales of unit numbers and various scenarios. Finally, the results confirm that the proposed scheduling framework is reasonable and effective in solving unit commitment problems, can achieve 3.3% cost reduction and demonstrates superior performance in handling large-scale energy optimization problems. The integration of plug-in electric vehicles, distributed renewable energy generations, and battery energy storage systems is verified to reduce the output power of 192.72 MW units during peak periods to improve grid stability. Therefore, optimizing energy utilization and distribution will become an indispensable part of future power systems.展开更多
To deal with the aerodynamic heating on the aircraft surface,a potential solution is to utilize liquid cooling via the channels in part of the fuselage.This is a typical problem of flow and heat transfer in channels w...To deal with the aerodynamic heating on the aircraft surface,a potential solution is to utilize liquid cooling via the channels in part of the fuselage.This is a typical problem of flow and heat transfer in channels with unilaterally-heated surfaces.The enhancement of heat transfer in the channel is significant due to the high heating flux.The optimal velocity and temperature fields are obtained first based on the field synergy optimization method.Four rib configurations are proposed to produce the longitudinal vortices suggested by the optimal velocity field.The flow and heat transfer characteristics of different rib configurations are obtained by numerical simulation.The numerical simulations show that the heat transfer enhancement of the rib configurations are quite different,but the pressure drop increases similarly in the laminar flow range of Re = 500–1500.The mechanism of heat transfer enhancement with the single/double-inclined ribs for the unilaterally-heated channel is analysed.The best enhancement of geometric parameter among the investigated parameters such as the angle,length,radius and the spacing of the ribs is obtained.展开更多
基金supported by National Natural Science Foundation of China under grants 52077213 and 62003332Youth Innovation Promotion Association CAS 2021358+1 种基金Shenzhen Science and Technology Research and Development Fund JCYJ20200109114839874NSFC-FDCT under its Joint Scientific Research Project Fund(Grant No.0051/2022/AFJ),China&Macao.
文摘Multi-energy synergy systems integrating high-penetration large-scale plug-in electric vehicles, distributed renewable energy generations, and battery energy storage systems have great potential to reduce the reliance of the grid on traditional fossil fuels. However, the random charging characteristics of plug-in electric vehicles and the uncertainty of photovoltaics may impose an additional burden on the grid and affect the supply–demand equilibrium. To address this issue, judicious scheduling optimization offers an effective solution. In this study, considering charge and discharge management of plug-in electric vehicles and intermittent photovoltaics, a novel Multi-energy synergy systems scheduling framework is developed for solving grid instability and unreliability issues. This formulates a large-scale mixed-integer problem, which calls for a powerful and effective optimizer. The new binary level-based learning optimization algorithm is proposed to address nonlinear large-scale high-coupling unit commitment problems. To investigate the feasibility of the proposed scheme, numerical experiments have been carried out considering multiple scales of unit numbers and various scenarios. Finally, the results confirm that the proposed scheduling framework is reasonable and effective in solving unit commitment problems, can achieve 3.3% cost reduction and demonstrates superior performance in handling large-scale energy optimization problems. The integration of plug-in electric vehicles, distributed renewable energy generations, and battery energy storage systems is verified to reduce the output power of 192.72 MW units during peak periods to improve grid stability. Therefore, optimizing energy utilization and distribution will become an indispensable part of future power systems.
基金supported by discipline construction fund of Tsinghua University。
文摘To deal with the aerodynamic heating on the aircraft surface,a potential solution is to utilize liquid cooling via the channels in part of the fuselage.This is a typical problem of flow and heat transfer in channels with unilaterally-heated surfaces.The enhancement of heat transfer in the channel is significant due to the high heating flux.The optimal velocity and temperature fields are obtained first based on the field synergy optimization method.Four rib configurations are proposed to produce the longitudinal vortices suggested by the optimal velocity field.The flow and heat transfer characteristics of different rib configurations are obtained by numerical simulation.The numerical simulations show that the heat transfer enhancement of the rib configurations are quite different,but the pressure drop increases similarly in the laminar flow range of Re = 500–1500.The mechanism of heat transfer enhancement with the single/double-inclined ribs for the unilaterally-heated channel is analysed.The best enhancement of geometric parameter among the investigated parameters such as the angle,length,radius and the spacing of the ribs is obtained.
