Ground-source Heat pump, R410A, Experimental investigation, Performance research, Test.
Abstract:Â Nowadays, in some small and medium-sized heat pumps, refrigerant R410A has been used widely because of the good thermodynamic performance and environmental protection. Firstly the principles of the system and the characteristics of refrigerant has been demonstrates. The paper has set up a heat pump system with the refrigerant R410A and the performance parameters under different working conditions were tested and analyzed. The results showed that when the condensation temperature increased from 30â„ƒ to 60â„ƒ, the cooling capacity decreased by 33%, the input power increased by 97.8%, and COP decreased by 66%. As the evaporation temperature increased from 0â„ƒ to 12.5â„ƒ, the refrigerating capacity increased by 55% and the input power increased by 20%. Drop in chilled water and cooling water flow rate are both harmful to the refrigeration capacity. Chilled water flow rate must be controlled higher than 35% of the rated flow rate. The inlet temperature of cooling water drops can improve the cooling capacity. When the cooling water inlet temperature increased from 18â„ƒ to 30â„ƒ, the unit COP decreased by 40.8%. Chilled water inlet temperature rise can improve the evaporation pressure of the system, and hereby improve the cooling capacity and COP. When the chilled water inlet temperature increased from 10â„ƒ to 25â„ƒ, COP improved by 63%.