Thermodynamic assessment of a large-scale magnetic air conditioning prototype

This study presents an experimental analysis of the thermodynamic performance of a large-scale magnetic air-conditioning system prototype that uses a combination of La(Fe,Mn,Si)13Hz and Gd in a sixteen-bed active magnetic regenerator (AMR) assembly. The performance of the system is compared with a previous version which operated in part load with eight regenerator beds and lower flow rates. The experiments were carried out in a relevant environment, characterizing a Technology Readiness Level (TRL) of 6, emulated by a calibrated calorimeter focusing on key performance metrics such as cooling capacity, coefficient of performance, and second-law efficiency. The experimental results demonstrate a maximum cooling capacity of 680 W, along with a temperature span of 8.7 K. Particularly noteworthy is the significant enhancement observed in the performance of the system when accounting for previously disregarded irreversibilities external to the active magnetic regenerators. From an AMR standpoint, the maximum values of the coefficient of performance and second law efficiency are 4.2 and 10.8%, respectively, but from the system perspective, these values are reduced to 0.41 and 0.84%, respectively.