Permanent magnet design for magnetic heat pumps using total cost minimization

Abstract

The active magnetic regenerator (AMR) is an attractive technology for efficient heat pumps and cooling systems. The costs associated with a permanent magnet for near room temperature applications are a central issue which must be solved for broad market implementation. To address this problem, we present a permanent magnet topology optimization to minimize the total cost of cooling using a thermoeconomic cost-rate balance coupled with an AMR model. A genetic algorithm identifies cost-minimizing magnet topologies. For a fixed temperature span of 15K and 4.2kg of gadolinium, the optimal magnet configuration provides 3.3kW of cooling power with a second law efficiency (ηII) of 0.33 using 16.3kg of permanent magnet material.