Numerical Analysis of the Influence of Flow Maldistribution at Both Ends of Regenerator

In this paper, a two-dimensional transient model of magnetic refrigeration system has been developed by means of Comsol 5.2. Two cases are considered. In case 1, the two ends of regenerator are directly connected to the cold and hot heat exchanger, respectively. While in case 2, transitional sections are used to connect regenerator and heat exchangers. The transitional sections are adiabatic and therefore include the effect of dead volume. The structure of regenerator in two cases is exactly same. Through case comparison, this work focuses on the influence of uneven flow at the both ends of regenerator due to abruptly changed flow area on the performance of magnetic refrigeration system. Numerical simulation results showed that the flow becomes more uniform in case 2. Compared with case 1, the no-load temperature span in case 2 increased by 40.16% from 18.65 K to 26.14 K. When the temperature span is 5 K, cooling power of case 2 increased by 31.57% compared with case 1, and the COP increased by 69.85%. Therefore, the effect of abruptly changed flow area at the both ends of regenerator on the performance of magnetic refrigeration system cannot be ignored. This work provides important reference for the structure design and improvement in magnetic refrigeration system.