室温磁制冷系统性能影响因素交互研究

Interactive Research on the Factors Influencing the Performance of Room Temperature Magnetic Refrigeration System

本文建立了主动磁回热器(AMR)瞬态数值模型,分析了系统运行参数、AMR结构参数及换热流体物性参数对室温磁制冷系统性能的影响。研究发现:对于系统运行参数,存在最佳流速和换热时间使制冷温跨、制冷量和放热量最大;此外,制冷温跨、制冷量和放热量随磁化时间的增大而减小。对于AMR结构参数,相对于增大AMR长度,增大直径可更显著的提升系统性能;当流速一定时,存在最佳孔隙率使制冷温跨、制冷量和放热量最大,且流速越大对应的最佳孔隙率越小。对于换热流体物性参数,流速较大时应选用小比热容、大导热系数的流体,流速小时选用大比热容、小导热系数的流体。

In this study,the transient numerical model of the active magnetic regenerator(AMR)is established,and the effects of system operating parameters,AMR structure parameters and physical parameters of heat transfer fluid on the performance of room temperature magnetic refrigeration system are analyzed.It is found that,for the system operating parameters,the refrigeration temperature span,cooling capacity and heat release can be maximized by optimal flow rate and heat transfer time.In addition,they also decrease with the increase of magnetization time.For the AMR structure parameters,increasing the diameter can more significantly improve the system performance than increasing the AMR length.When the flow velocity is fixed,the optimal porosity maximizes the cooling temperature span,cooling capacity and heat release,and the higher the flow velocity,the smaller the optimal porosity.For the physical property parameters of heat transfer fluid,the fluid with small specific heat capacity and large thermal conductivity should be selected for the large flow velocity,and the fluid with large specific heat capacity and small thermal conductivity should be selected when the flow velocity is small.