电动汽车的发展普及与V2G(Vehicle to Grid)思想的提出,对微电网系统的经济、安全运行带来了新的挑战,如何合理调度电动汽车有序充放电,促进微电网的经济、平稳运行成为当下的研究热点。针对含电动汽车的风光储并网型微电网环境,构建了...电动汽车的发展普及与V2G(Vehicle to Grid)思想的提出,对微电网系统的经济、安全运行带来了新的挑战,如何合理调度电动汽车有序充放电,促进微电网的经济、平稳运行成为当下的研究热点。针对含电动汽车的风光储并网型微电网环境,构建了最小化微电网与外部电网交互功率和平抑可再生能源功率波动的多目标调度优化模型。通过对某商业区域微电网运行算例的仿真求解,从微电网运行经济效益、日交互电量以及出力功率平均变化量等方面验证了所建模型的合理性和正确性。算例结果表明,以微电网为平台集成利用具有一定出行规律的电动汽车与可再生能源是一种理想的协同利用模式,既可以提高微电网运行的经济效益,又能有效改善微电网的交互功率和出力波动。展开更多
Numerical simulation has been carried out to investigate the major factors affecting the time of composite regeneration due to coupling cerium-based additive and microwave for diesel particulate f3ilter(DPF). Effect o...Numerical simulation has been carried out to investigate the major factors affecting the time of composite regeneration due to coupling cerium-based additive and microwave for diesel particulate f3ilter(DPF). Effect on the composite regeneration time from various factors such as mass flow rate of exhaust gas, temperature of exhaust gas, oxygen concentration of exhaust gas, microwave power and amount of cerium-based additive are investigated. And a mathematical model based on fuzzy least squares support vector machines has been developed to forecast the endpoint of the composite regeneration. The results show that the relative error of endpoint forecasting model of composite regeneration is less than 3.5%, and the oxygen concentration of exhaust gas has the biggest effect on the endpoint of composite regeneration, followed by the mass flow rate of exhaust gas, the microwave power, the temperature of exhaust gas and the amount of cerium-based additive.展开更多
A novel shrouded wind-solar hybrid renewable energy and rain water harvester with an omni-directional-guide-vane(ODGV) for urban high-rise application is introduced.The ODGV surrounds the vertical axis wind turbine(VA...A novel shrouded wind-solar hybrid renewable energy and rain water harvester with an omni-directional-guide-vane(ODGV) for urban high-rise application is introduced.The ODGV surrounds the vertical axis wind turbine(VAWT) and enhances the VAWT performance by increasing the on-coming wind speed and guiding it to an optimum flow angle before it interacts with the rotor blades.An ODGV scaled model was built and tested in the laboratory.The experimental results show that the rotational speed of the VAWT increases by about 2 times.Simulations show that the installation of the ODGV increases the torque output of a single-bladed VAWT by 206% for tip speed ratio of 0.4.The result also reveals that higher positive torque can be achieved when the blade tangential force at all radial positions is optimized.In conclusion,the ODGV improves the power output of a VAWT and this integrated design promotes the installation of wind energy systems in urban areas.展开更多
Wind energy is one of the most promising renewable energy sources, straight-bladed vertical axis wind turbine(S-VAWT) appears to be particularly promising for the shortage of fossil fuel reserves owing to its distinct...Wind energy is one of the most promising renewable energy sources, straight-bladed vertical axis wind turbine(S-VAWT) appears to be particularly promising for the shortage of fossil fuel reserves owing to its distinct advantages, but suffers from poor self-starting and low power coefficient. Variable-pitch method was recognized as an attractive solution to performance improvement, thus majority efforts had been devoted into blade pitch angle effect on aerodynamic performance. Taken into account the local flow field of S-VAWT, mathematical model was built to analyze the relationship between power outputs and pitch angle. Numerical simulations on static and dynamic performances of blade were carried out and optimized pitch angle along the rotor were presented. Comparative analyses of fixed pitch and variable-pitch S-VAWT were conducted, and a considerable improvement of the performance was obtained by the optimized blade pitch angle, in particular, a relative increase of the power coefficient by more than 19.3%. It is further demonstrated that the self-starting is greatly improved with the optimized blade pitch angle.展开更多
文摘电动汽车的发展普及与V2G(Vehicle to Grid)思想的提出,对微电网系统的经济、安全运行带来了新的挑战,如何合理调度电动汽车有序充放电,促进微电网的经济、平稳运行成为当下的研究热点。针对含电动汽车的风光储并网型微电网环境,构建了最小化微电网与外部电网交互功率和平抑可再生能源功率波动的多目标调度优化模型。通过对某商业区域微电网运行算例的仿真求解,从微电网运行经济效益、日交互电量以及出力功率平均变化量等方面验证了所建模型的合理性和正确性。算例结果表明,以微电网为平台集成利用具有一定出行规律的电动汽车与可再生能源是一种理想的协同利用模式,既可以提高微电网运行的经济效益,又能有效改善微电网的交互功率和出力波动。
基金Projects(51176045,51276056)supported by the National Natural Science Foundation of ChinaProject(201208430262)supported by the National Studying Abroad Foundation Project of China
文摘Numerical simulation has been carried out to investigate the major factors affecting the time of composite regeneration due to coupling cerium-based additive and microwave for diesel particulate f3ilter(DPF). Effect on the composite regeneration time from various factors such as mass flow rate of exhaust gas, temperature of exhaust gas, oxygen concentration of exhaust gas, microwave power and amount of cerium-based additive are investigated. And a mathematical model based on fuzzy least squares support vector machines has been developed to forecast the endpoint of the composite regeneration. The results show that the relative error of endpoint forecasting model of composite regeneration is less than 3.5%, and the oxygen concentration of exhaust gas has the biggest effect on the endpoint of composite regeneration, followed by the mass flow rate of exhaust gas, the microwave power, the temperature of exhaust gas and the amount of cerium-based additive.
基金Project (RG039-09AET) supported by University of Malaya, Malaysia
文摘A novel shrouded wind-solar hybrid renewable energy and rain water harvester with an omni-directional-guide-vane(ODGV) for urban high-rise application is introduced.The ODGV surrounds the vertical axis wind turbine(VAWT) and enhances the VAWT performance by increasing the on-coming wind speed and guiding it to an optimum flow angle before it interacts with the rotor blades.An ODGV scaled model was built and tested in the laboratory.The experimental results show that the rotational speed of the VAWT increases by about 2 times.Simulations show that the installation of the ODGV increases the torque output of a single-bladed VAWT by 206% for tip speed ratio of 0.4.The result also reveals that higher positive torque can be achieved when the blade tangential force at all radial positions is optimized.In conclusion,the ODGV improves the power output of a VAWT and this integrated design promotes the installation of wind energy systems in urban areas.
基金Project(HEUCF110707)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(E201216)supported by Heilongjiang Natural Science Fund,China
文摘Wind energy is one of the most promising renewable energy sources, straight-bladed vertical axis wind turbine(S-VAWT) appears to be particularly promising for the shortage of fossil fuel reserves owing to its distinct advantages, but suffers from poor self-starting and low power coefficient. Variable-pitch method was recognized as an attractive solution to performance improvement, thus majority efforts had been devoted into blade pitch angle effect on aerodynamic performance. Taken into account the local flow field of S-VAWT, mathematical model was built to analyze the relationship between power outputs and pitch angle. Numerical simulations on static and dynamic performances of blade were carried out and optimized pitch angle along the rotor were presented. Comparative analyses of fixed pitch and variable-pitch S-VAWT were conducted, and a considerable improvement of the performance was obtained by the optimized blade pitch angle, in particular, a relative increase of the power coefficient by more than 19.3%. It is further demonstrated that the self-starting is greatly improved with the optimized blade pitch angle.
