13. Air-Condition and Refrigeration

A magnetocaloric heat pump has a higher theoretical coefficient of performance than a conventional vapor compression heat pump. It also has the advantage of not leaking a refrigerant into the atmosphere because it uses a solid-state one. However, at the current research stage, it has not yet been commercialized because of its lower refrigeration capacity and higher cost compared to the vapor compression heat pump system. Though many studies have been conducted to evaluate the refrigeration capacity of the magnetocaloric heat pump operated in an active magnetic regenerator (AMR) cycle using the type of magnetocaloric material and the flow rate of the heat exchange medium. On the other hand, the refrigeration capacity of AMR depends on the magnetic field intensity imparted to the magnetocaloric material. It is important to understand the relation between the applied magnetic field strength and the refrigeration capacity for designing that systems. However, it is not realistic to conduct the experimental characterization using the applied magnetic field intensity as a parameter because of the high cost for magnetic circuit production. In this study, the effect of applied magnetic field intensity on the refrigeration capacity and the maximum temperature difference generated were clarified using a numerical simulation. As a result, it was found that the applied magnetic field intensity of 1.5T were about three times greater than those of 0.5T, both in terms of refrigeration capacity and maximum temperature difference generated.