Experimental Research On Deep Supercooling Heat Recovery System Design Of Air-Cooled Screw Heat Pumps

In this paper,a heat recovery solution is proposed based on existing R134 a air-cooled screw heat pumps by theoretical analysis and design calculation,to provide hot water by subcooling liquid from outlet of condenser;Related experiments were carried out on one modified 200 TR air-cooled screw heat pump,and it is shown that the theoretical calculation results are basically consistent with experimental data.Studies have shown that deep subcooled heat recovery is higher than sensible heat recovery both under rated cooling and heating,which has little effect on original system performance;heating capacity is almost same while cooling capacity even higher.Considering rated COP,cooling COP is improved by 2.9% but heating COP is decreased by 16.7%;as real benefit,heat recovery is suggested to be included,thus integrated cooling and heating COP can reach 3.80 and 2.95 separately,increased by 23.4% and 2.8% compared with original system.Due to the two systems running independently by heat exchange in subcooler,there's no change to refrigerant charge,unit operation envelop and reliability.However,suction pressure is lower with deep subooling heat recovery system enabled,which may due to low suction alarm under low ambient temperature heating(lower than-5?),and bring reliability impact.