The heat transfer properties and performance of parallel plate active magnetic regenerators (AMR) with heterogeneous plate spacing are investigated using detailed models previously published. Bulk heat transfer characteristics in the regenerator are predicted as a function of variation in plate spacing. The results are quantified through a Nusselt number scaling factor that is applied in a detailed 1D AMR model. In this way, the impact of flow maldistribution due to heterogeneous parallel plate stacks on AMR performance is systematically investigated. It is concluded that parallel plate stacks having a standard deviation greater than about 5 % on their plate spacing are severely penalized in terms of both cooling power and achievable temperature span due to the inhomogeneity of the stacks.
Journal of Physics D: Applied Physics, 2013, Vol 46
Flow maldistribution; Active magnetic regenerator; Parallel plate heat exchanger; Magnetocaloric effect; Magnetic refrigeration