Experimental studies on a closed cycle compressor operated metal hydride based cooling system with large hydrogen inventory

The current manuscript reports the experimental results of a closed loop metal hydride (MH) based compressor driven cooling system (CDCS) employing large-scale reactors. Two identical tube bundle reactors (TBR) with 19 MH tubes were designed, constructed and packed with 26.5 kg La0.8Ce0.2Ni5 alloy each for the experiments. The TBR modules were coupled with a custom-built compressor to provide cooling effect in quasi-continuous mode of operation. The compressor was tested to operate smoothly up to a hydrogen flow rate of 0.5 g. s(-1) in the temperature range of 10e35 degrees C, yielding pressure ratio up to 12.8. Test runs were performed by altering refrigeration temperature (10-20 degrees C), sink temperature (30-35 degrees C), and half-cycle time (120-600 s). The maximum cooling power attained at 20 degrees C refrigeration temperature and 30 degrees C sink temperature was 1.44 kW, generating 537.3 kJ cooling within 600 s. The corresponding mean coefficient of performance (COP) and specific cooling power (SCP) were 0.95 and 36.4 W.kg(-1) for 480 s half-cycle time. To avoid overheating of the compressor base, the half-cycle time was restricted to maximum of 600 s. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.