Study of the performance coefficient of an active magnetic regenerative refrigeration system.

This work seeks to study the coefficient of performance (COP) of an active magnetic regenerative refrigeration system. The refrigeration system is consisted of a fluid circulating between a cold and a hot source, active regenerator is formed by parallel plates of gadolinium, a circulation pump, a rotating magnet and two heat exchangers to transfer heat between the fluid and the two sources. Thermodynamic, fluidic and magnetic models were carried out. The supplied works within the system were determined to calculate the COP such as the work of the circulating pump (Wp), the work of engine turning the magnet (We) and the magnetic work (Wm). Contrary to Wp and We calculations, Wm calculation is not classic. To study the COP, different exchanged heats within a cycle were calculated: the heat (Qc) recovered from the cold source, the heat (Qh) rejected to the hot source and the heat regenerated by the gadolinium (Qr). In this study, Qc was given by hypothesis, and Qh is determined by the first thermodynamic principle. While Qr was numerically determined after an optimization of system operating parameters. A resolution of the continuity equation, the amount of movement equation and the heat equation were carried out in order to study the temperature profile in the regenerator and the fluid. Then, we deduce the temperatures at the inlet and the outlet of the heat exchangers which help us to do the thermal balance. In this studied, the COP values of the magnetic refrigeration system are considered as significant.