Theoretical And Experimental Study On New Alternative Refrigerants

Commonly used refrigerants such as HCFC-22 and R502 have nonzero ODP and high GWP. According to Montreal Protocol and related revisions, HCFC-22 should be phased out before 2020 in developed countries and the deadline for R502 is 1996. Most of their alternative refrigerants are finalized products of foreign corporations, which still have high GWP. The aim of this study is to develop new alternative refrigerants with good properties and own intellectual property rights.Using environmental considerations as primary criterion in alternative refrigerants selecting, pure substance of HFC-161 with friendly environmental properties is selected from halogen derivatives of methane and ethane. Combined with other selecting criteria, ternary mixtures of HFC-161 are firstly put forward as new alternative refrigerants.The influences of each composition to the whole properties of HFC-161 mixtures are analyzed, such as environmental properties, thermodynamic characteristics, safety and theoretical cycle performances. Ml, HFC-161/125/32 (mass ratio 51/34/15%) is then determined to be a new alternative refrigerant to HCFC-22. M2, HFC-161/125/143a (mass ratio 10/45/45%) is proposed to be an alternative refrigerant to R502. M3, HFC-161/125/32 (mass ratio 15/42.5/42.5%) is put forward to be a new alternative refrigerant to R410A.Environmental properties and thermodynamic characteristics between new and traditional working substances are compared. Extended corresponding states model is used to calculate the theoretical cycle performances of new working substances under rating and varying working conditions. Their flammability is discussed as well. Theoretical model is established to calculate the variation of composition and corresponding properties after refrigerant leakage.Drop-in experiments are performed in practical systems. The performances of Ml and HCFC-22, R407C are studied on an air-water heat pump. An experimental apparatus is designed and set up according to GB5773-86 to compare the performance of M2 and R404A, primary alternative refrigerant of R502. The effectiveness of M3 and R410A in new designed system is compared using enthalpy-difference method.Theoretical analyses as well as experimental results prove that these new working substances are environmentally friendly. There is no obvious difference between their cycle performances and those of traditional ones, which meets the corresponding requirements of alternative refrigerants. Their combustion probability is low. The performance variation after leakage satisfies with national standard. It is worth further research.