Abstract

This study introduces a groundbreaking magnetocaloric heat pump (MCHP) system that replaces traditional rare earth-dependent fixed-bed regenerators with a MnFePSi nanoparticle slurry (50 nm, 10% vol.), achieving simultaneous refrigerant and heat transfer functions. Experimental evaluations under controlled conditions (23°C ±0.2°C, 10 K span) demonstrate a 14.6% improvement in coefficient of performance (COP), 33.4% higher specific power density, and 24.8% system mass reduction compared to conventional gadolinium-based systems. The slurry’s non-Newtonian rheology enables rapid thermal response (56.3% faster) and exceptional temperature uniformity (±0.8°C), while operating at frequencies up to 7.6 Hz.

Key innovations include a proprietary experimental platform integrating real-time spin-state monitoring, nano-Hall magnetic field mapping, and coupled CFD-ML modeling. Extended stability tests reveal minimal performance degradation (1.3% COP reduction over 48 hours) and negligible nanoparticle agglomeration (<2%). The complete elimination of rare earth elements reduces lifecycle environmental impact by 60%, addressing critical sustainability challenges in cooling technology.

These results establish the first practical demonstration of a rare-earth-free magnetocaloric cooling system with superior efficiency, scalability, and material utilization—setting a new benchmark for sustainable thermal management solutions. The technology’s compact design and enhanced heat transfer coefficients (22% improvement over fixed beds) position it as a transformative approach for next-generation refrigeration, air conditioning, and waste heat recovery applications.