Simulations and design of a refrigerating device based on a rotating magnetocaloric disc.

The possibility of utilizing a Gd disc as an active magnetic regenerator (AMR) is investigated. We have designed a demonstration device based on a rotating disc with a fixed magnetic circuit covering one quarter of its area. The device implies zero thermal load with the operation fluid flowing through. Simulations are based on discretization of the heat transfer equations for the disc and the fluid domains using the finite difference method. The magnetocaloric effect (MCE) is included in the model as an instantaneous adiabatic temperature change of each element entering the magnetic field. Regenerative effect is obtained as at each radius of the disc the magnetocaloric material (MCM) operates switching its temperature around a different average, which decreases from periphery to centre. This allows the total temperature drop of the operational fluid to be several times larger than the adiabatic temperature change.

本研究探讨了将钆（Gd）圆盘用作主动磁蓄冷器（active magnetic regenerator, AMR）的可行性。我们设计了一款演示装置，其核心为旋转圆盘，搭配覆盖圆盘四分之一区域的固定磁路。该装置在工作流体流经时可实现零热负荷。仿真基于有限差分法，对圆盘与流体区域的传热方程进行离散化处理。模型中将磁热效应（magnetocaloric effect, MCE）定义为每个进入磁场的单元的瞬时绝热温变。该装置的蓄热效应源于：圆盘各半径处的磁热材料（magnetocaloric material, MCM）围绕不同的平均温度进行温度切换，且平均温度从圆盘外缘向中心逐渐降低。这使得工作流体的总温降可达绝热温变的数倍。