Performance Study On Water Source Heat Pump Units Based On Environment-friendly Refrigerant

Traditional refrigerant R22 is not only destructive to the ozone layer but also exacerbates the greenhouse effect,whlie countries are in accordance with the "Montreal Protocol" and related laws,in 2020-2030 years,gradually eliminated traditional refrigerant,so the study of a new generation of zero ODP and low GWP alternative refrigerant is extremely urgent.In the highly efficient energy-saving and high-demand heat pump industry,there is not yet a new type of refrigerant which can achieve good replacement in environment,thermal and safety.The purpose of this paper is to find a new type of mixed refrigerant of independent intellectual property,that can be completely replaced at long-term in this field.In this paper,alternative principles and objectives are proposed in terms of environmental properties,thermo-phsical,safety,compatibility and economy.According to this goal,the three complementary components of R1234ze(E),R32 and R134a are found.Theoretically,Environmental and thermal performance were calculated and analyzed.The optimal combination ratio NC001,R32/R1234ze(E)/R134a(50/17/33),was selected as the main research object of the alternative experiment.ODP of NC001 is zero,GWP value is only 44%of R22,and CO2 emissions is 48%.Boiling point,latent heat and other basic properties of NC001 are closed to the R22.At the same time,as non-azeotropic refrigerant,whose the slip temperature is about 5?,non-toxic and non-flammable,are suitable for direct replacement.In the experiment,R22,R32,R1234ze(E)and NC001 were directly charged on the water source heat pump unit,the evaporate/condenser side carry out the cycle performance test which is in accordance with 4/5?5/6?6/7 m3/h respectively in different float rates and different state of regenerator.The experimental results show that the heating capacity of the new mixed refrigerant NC001 is 10-22%higher than R22,and the thermal ratio and circulation are close to R22.When the temperature of the second cycle of water at 12-23?,COP of NC001 is slightly lower than 0-14%of R22,when exceeding 23?,COP is higher than R22.At the same time,the experiment also found that opened the regenerator in summer and closed in winter were benefit to improving heating,while the second cycle water flow had little impact on the NC001.The new hybrid alternative refrigerant NC001 basically meets the replacement objectives and principles,which is considered to have a substitute advantage in the field of water source heat pump.It is necessary to carry-out further study to improve the confficient of the system,at the same time reduce the impact on the environment.