本文对二元混合工质HFcl52a/HcFc22、HFcl52a/HFcl25在冰箱上应用的制冷循环性能进行了详细的理论计算和析，并且对这两种混合工质灌注式替代CFCl2，在最佳配比和充灌量下的冰箱主要制冷性能进行了对比试验研究。试验结果表明：在合适的配比和充灌量下混合工质冰箱制冷性能指标满足国家标准要求，HFcl52a/HFcl25在最佳充灌量为97g时，试验冰箱耗电量为1.156kW·h/24h，比CFCl2节能10%，比HFcl52a/HcFc22节能O.81%。因此HFCl52a/HFCl25比HFCl52a/HCFC22更适合于灌注式替代CFCl2。

spherical resonator and acoustic signal measurement apparatus have been designed and developed for measuring the speed of sound in the gaseous phase. The inner radius of the spherical resonator, being about 6.177cm, was determined by measuring the speed of sound in gaseous argon at temperatures between 293 and 323K and at pressures up to 200kPa. Measurements of the speed of sound in four halogenated hydrocarbons are presented, the compounds are chlorodifluoromethane (CHClF2 or HCFC-22), 1, 1-difluoroethane (CH3CHF2 or HFC-152a), 1, 1, 1-trifluoroethane (CH3CF3 or HFC-143a), and propane (CH3CH2CH3 or HC-290). Ideal-gas heat capacities and acoustic virial coefficients were directly deduced from the present data. The results were compared with those from other studies. In this work, the experimental uncertainties in temperature, pressure, and speed of sound are estimated to be less than

The performances of a refrigeration cycle of a 1, 1-difluoroethane/pentafluoroethane (HFC152a/HFC125) mixture used as a refrigerant for domestic refrigerators were calculated and analyzed in detail. The results of the theoretical analysis indicate that the HFC152a/HFC125 mixture in the composition of 0.85 mass fraction of HFC152a has a similar refrigeration performance with the existing refrigerant CFC12. Experimental research on the main refrigeration performances of domestic refrigerators was conducted, under the different proportions and charge amounts, when HFC125a/HFC125 is used to substitute CFC12 as a "drop-in" refrigerant. The experimental results indicate that the refrigeration performances of the domestic refrigerator charged with the new refrigerant can meet the requirement of the National Standard of China, under the appropriate proportion and the optimum charge amount. In conclusion, the mixing refrigerant HFC152a/HFC125 proposed in this study seems to be an appropriate long term candidate to replace CFC12 as a new generation refrigerant of domestic refrigerators, because of its well environmentally acceptable properties and its favorable refrigeration performances.

Eighty-four speed of sound values in gaseous mixtures of the refrigerants difluoroethane (CH3CHF2, HFC152a)+ difluoromethane (CHClF2, HCFC22) have been measured for temperatures from 293 to 323K, pressure from 200 to 405kPa, and mass fractions of HCFC22 of 13.8 and 25.5% with a spherical acoustic resonator. The experimental uncertainties in the temperature, pressure and speed of sound in gas are estimated to be less than

A new transport equation of state to estimate the thermal conductivity and the viscosity of the dense fluid for halogenated hydrocarbon refrigerants is presented and the relationships between the reduced residual transport properties and the reduced density were determined. This approach originated from the phenomenological similarity between the reduced residual transport properties and the reduced density in terms of pressure and temperature over the entire thermodynamic surface. The new equation can be used to calculate the thermal conductivity and the viscosity of the dense fluid including the vapor and liquid region with high accuracy, based on the calculation on the transport properties of gases at lowpressure. The only input data needed are the critical parameters, molecular weight and acentric factor. The method is based on the concept of the transport equation of state describing the transport properties in terms of pressure and temperature by pressure explicit equations similar to a thermal equation of state. Coherence between the transport properties and equilibrium properties over the entire fluid range was reflected. The absolute average deviation of the thermal conductivity of halogenated hydrocarbon refrigerants is 4.8% with a maximum deviation of 18.0%, and the absolute average deviation of the viscosity of halogenated hydrocarbon refrigerants is 4.% with a maximum deviation of 15.6%, using the new equation. A new generalized correlation to estimate the thermal conductivity of halogenated hydrocarbon refrigerants at low pressure is also proposed. The range of application of this newformula is for reduced temperatures between 0.6 and 1.2 and for values of the critical compressibility factor between 0.225 and 0.283. The calculation deviation is within