Improving magnetic cooling efficiency and pulldown by varying flow profiles

Magnetic refrigeration systems are promising cooling solutions that employ the active magnetic regenerator cycle to achieve practical temperature spans and environmental benefits. The hydraulic system ensures a continuous flow of heat transfer fluid through with reciprocating in each bed is critical performance cycle. Hence, we investigate characteristics parallel circuit rotary system, which consists thirteen trapezoid-shaped regenerators, filled 295 g gadolinium spheres. Fluid controlled via electrically actuated solenoid valves (both piloted direct-acting) connected hot side. By varying percentage opening control valves, different blow fractions (or waveforms) could be investigated. objective study twofold: (i) assess whether imbalances exist cold-to-hot (cold blow) hot-to-cold (hot directions, (ii) determine there an optimal value fraction both maximize realize rapid pulldown. Flow resistance measurements demonstrate symmetric design resistances similar cold directions. Moreover, for studied 6 K 16 K, best was found about 41.6 %. For instance, at span, utilization 0.32, 1.4 Hz, increasing from 25.0 % enhanced capacity second-law efficiency 70 330 W 2.6 17.4 %, respectively. In turn, lower favored more magnetocaloric 30 faster establishing approximately 14 span when reduced 30.6 can benefit greatly allow operate either time-saving mode or energy-saving mode.