Numerical Simulation of Active Magnetic Regenerative Refrigerators

The paper presents a theoretical study of the heat transfer and thermodynamic performance for a rotary magnetic refrigerator with an active magnetic regenerator (AMR). The theoretical models were proposed for the refrigerator with AMR using two different kinds of heat transfer channel designs, one is packed gadolinium bed with porous magnetic materials, and another is packed gadolinium bed with micro heat pipe. Numerical results reveal heat transfer performance of AMR which is installed micro heat pipe is better than AMR which is packed with porous material. It shows that heat transfer increases with heat pipe numbers, low rotary frequencies are beneficial to heat transfer both in magnetization and demagnetization processes, but low rotary frequencies limits the output power of refrigerator, so the optimized rotary frequency is 10-15 rev. /minute. It has also been detected that the boundary layer in heat transfer fluid is seriously affected by the micro heat pipe location for larger convection coefficient conditions.