Improvement of the AMR's performance: multi-segment regenerator and by-pass flow.

This paper analyses the improvement of an Active Magnetic Regenerator performance by two methods. The first one is the layering of several magnetocaloric materials in series by their Curie temperature in order to create a higher temperature span. The second method is the use of a countercurrent heat exchanger by-pass flow to increase the machine’s final Coefficient of Performance and cooling power. A time-dependent numerical model was used to analyze multiple cases of magnetocaloric segment layering. The best layering was identified and compared with the by-pass configuration. Some interesting results were obtained which highlighted the point that the joint use of a by-pass on a magnetic refrigeration system with proper MCM segment layering significantly changes the behavior of an AMR. These results were compared to experimentally-obtained data from an existing rotary research prototype which had been specially adapted to fit the requirements of these new operating methods.