Simulation of a hydraulic circuit for a magnetic refrigerator.

The flow distribution system plays a key role in the operation and the overall performance of a magnetic refrigerator, but only a few works in the literature are dedicated to the design and evaluation of it. Therefore, the focus of this work was to evaluate the transient behavior of a flow management system by means of numerical simulations of a simplified hydraulic circuit of the magnetic refrigerator developed at POLO/UFSC using a commercial software package. Water hammers were predicted to occur after switching the fluid flow direction, and their magnitude was proportional to the volumetric flow rate. The performance of the hydraulic system showed a dependence on the valve opening ramp; while fast ramps increased the magnitude of the water hammer, slow ramps led to fluid flow bypassing the AMR. The use of a proportional returning valve upstream of the high-pressure valves is recommended to absorb the impact of the water hammers and make the flow through the regenerator beds smoother.