Dynamic 1D model of an Active Magnetic Regenerator: a parametric investigation

A one dimensional dynamic model of a reciprocating active reciprocating magnetic regenerator (AMR) was developed and a parametric analysis of its behavior at near room temperature conditions was carried out. The investigation is focused on the thermal behavior of the regenerator alone, regardless of the apparatus in which it could work. The parametric investigation aims at evaluating the influence on the AMR performances of the operating frequency and fluid mass flow rate, that is the parameters that can be tuned in a given actual device. The performance parameters analyzed are refrigeration capacity, temperature span, coefficient of performance and second law thermodynamic efficiency. A standard geometry of the AMR was assumed, while the results are given in a non-dimensional form with reference to a conventional operating condition. Simulations show that the refrigeration capacity is very sensitive to the utilization factor, that causes a 20% refrigeration capacity reduction with a variation of -20% or +10%. The coefficient of performance (COP) is poorly influenced by Φ. Frequency variations induce a linear variation in refrigeration capacity, and a decrease in COP due to friction in the intermediate fluid. The second law thermodynamic efficiency trends show that friction and heat transfer irreversibility dominates at low and high temperature spans, respectively.