Cycle Through Magnetocaloric Parameter Deduced by Langevin Theory
Zhang Yan,Yu Bingfeng£¬Gao Qiang,Wang Congfei
(School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
Abstract:A new expression of magnetocaloric parameters,which is much more brief than original ones,was deduced using Langevin theory along with statistical mechanics and thermodynamics.The computation was conducted for Gadolinium.The comparisons between experiments and the results calculated from the original parameters were performed.The results show that the two sets of parameters are accordant well in the range of room temperatures.Moreover,a numerical simulation was carried out for the regenerative room-temperature magnetic refrigeration cycle based on the new parameters£®The simulation results indicate that the coefficient of performance (¦ÅCOP)decreases with the increase of TH of the high-temperature heat reservoir.In addition,the maximum of TH increases while TL of low-temperature heat reservoir increases.A higher magnetic field can improve ¦ÅCOP but the increase rate of ¦ÅCOP reduces£®
Keywords£ºLangevin theory;magnetocaloric parameter;room-temperature magnetic refrigeration;temperature of heat reservoir;coefficient of performance