Investigation on The Chlorine Free Hfc Refrigerants

Investigation on the chlorine free HFC refrigerants which have both advantages of HFC and HCFC. So the new study on blending of hydroflurocarbon takes place and new gases are formed such as R507A and R417a. All the Blend mixtures are not the solution for the replacement of existing refrigerant because GWP of the mixed refrigerant should be less than present using refrigerant. Among the blend mixtures, R417a had given the better results and had capacity to replace the present using R22 applications. R147a utilises less power consumption than R22 where the experiment carried on the same apparatus and same operating conditions.

Refrigerant R417a comprises of R125, R134 and R600.Binit Kumar Jha has done the theoretical study between the eco friendly R600a refrigerant and the widely used R134a refrigerant and abserved that the discharge pressure of R600 is less than that of R134a and the refrigerant effect and the coefficient of performance is comparatively high for R600a than R134a.Adil F. Momin and Manish H. Attal carried out experimental tests on the domestic refrigerator using phase change materials with R290/R600a blend as a refrigerant, while the PCM used is ethylene glycol, coated on the back side of the evaporator.

Addition of PCM enhance the heat transfer and elevate the evaporating temperatures. Thermal energy stored in the PCM is used during the off cycles which helps in the continuous refrigeration operation.. This lead to increase in the coefficient of performance and decrease in the refrigerant cycling time Research to find a replacement refrigerant R134a have been carried out by several previous researchers. Prayudi and Roswati Nurhasanah also had a performance analysis on the R600a and R134a refrigerants with the subcooling effect using the liquid suction heat exchangers with cooling load. Cooling load variations are done by opening the valve at different positions. There is no impact on the compressor work due to cooling load and compressor work increases with the subcooling effect.

Greater the sub cooling temperature, greater the temperature drop in the evaporator and R600a is giving better results when compared to Prayudi Suparmin has done a experimental analysis on the different refrigerants for different degree of subcooling. He had used the liquid suction heat exchanger for the different degree of subcooling and said that on subcooling the refrigerant which tends to prevent the flash gas formation at the throttle valve. From the experiment he showed, the effectiveness of LSHE increases with the increase in degree of subcooling. He showed the mixture of R290 and R600a in the ratio of 50: 50 in a refrigeration system is having the highest effectiveness of LSHE when compared to other refrigerants