The formed characteristics of thin-wall part is studied when it is in the process of MPAW. Finite element method is used to sinmlate the temperature field coupling flow field in the welding of thin-wall part. It is fo...The formed characteristics of thin-wall part is studied when it is in the process of MPAW. Finite element method is used to sinmlate the temperature field coupling flow field in the welding of thin-wall part. It is found that because of the obvious effect of heat accumution in cross-section, where the distribution of temperature field area presents trapezoidal inverted approximately in the molten pool and the non-molten pool area presents level. The surface tension, the electromagnetic force and buoyancy are considered for analyzing the effects on the fluid flow of welding-pool. It can be obtained that the surface tension is the main driving force in the welding pool, which is far greater than electromagnetic force and buoyancy.展开更多
【目的】为了有效提升压缩空气储能(compressed air energy storage,CAES)系统的储能特性和系统效率,对各部件的性能及其耦合特性进行了建模分析。【方法】针对CAES系统,应用标准热阻方法考虑换热部件的传递特性,结合储气装置与做功部...【目的】为了有效提升压缩空气储能(compressed air energy storage,CAES)系统的储能特性和系统效率,对各部件的性能及其耦合特性进行了建模分析。【方法】针对CAES系统,应用标准热阻方法考虑换热部件的传递特性,结合储气装置与做功部件模型,构建传热、储气、做功耦合的完整热力学模型及能量、㶲分析模型,评价了压缩和膨胀过程中储(释)能质量流量比对系统性能的影响。揭示储气库最高储气压力与体积之间的关系对系统储能效率及储能密度的影响规律。【结果】随着储(释)能质量流量比的增加,压缩机的总能耗先降低后升高,膨胀机的输出功是先上升后降低,当储(释)能的质量比分别为1.2和1.3时,系统效率达到最高,为53.65%;另外,系统中首级压缩和膨胀机的㶲损最大,油-气换热器和压缩机的㶲损占系统总㶲损的69%。【结论】所建模型和研究结果对CAES运行策略具有一定的指导意义。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.U1333128,U1733125)Science and Technology Project of Tianjin(Grant No.14ZCDZGX00802,17JCZDJC38700)
文摘The formed characteristics of thin-wall part is studied when it is in the process of MPAW. Finite element method is used to sinmlate the temperature field coupling flow field in the welding of thin-wall part. It is found that because of the obvious effect of heat accumution in cross-section, where the distribution of temperature field area presents trapezoidal inverted approximately in the molten pool and the non-molten pool area presents level. The surface tension, the electromagnetic force and buoyancy are considered for analyzing the effects on the fluid flow of welding-pool. It can be obtained that the surface tension is the main driving force in the welding pool, which is far greater than electromagnetic force and buoyancy.
文摘【目的】为了有效提升压缩空气储能(compressed air energy storage,CAES)系统的储能特性和系统效率,对各部件的性能及其耦合特性进行了建模分析。【方法】针对CAES系统,应用标准热阻方法考虑换热部件的传递特性,结合储气装置与做功部件模型,构建传热、储气、做功耦合的完整热力学模型及能量、㶲分析模型,评价了压缩和膨胀过程中储(释)能质量流量比对系统性能的影响。揭示储气库最高储气压力与体积之间的关系对系统储能效率及储能密度的影响规律。【结果】随着储(释)能质量流量比的增加,压缩机的总能耗先降低后升高,膨胀机的输出功是先上升后降低,当储(释)能的质量比分别为1.2和1.3时,系统效率达到最高,为53.65%;另外,系统中首级压缩和膨胀机的㶲损最大,油-气换热器和压缩机的㶲损占系统总㶲损的69%。【结论】所建模型和研究结果对CAES运行策略具有一定的指导意义。
