Experimental Evaluation of the Effect of Refrigerant Charge and Capillary Tube Length on the Performance of Household Refrigerator with Different Configurations of R290 and R600a

Abstract

In the present work the experimental investigation of a household refrigerator was calculated by simultaneously changing the refrigerant charge (mr) and length of capillary tube (Lc).The recent literature review shows the consistent research in the field of new refrigerants for usage in the refrigeration and air conditioning systems due to increased need and importance on the climate change effects faced by the humankind. The recent decades show the replacement of CFCs with HFCs, later with mixture of HFCs. But the high GWP value of HFCs paved the way for the development of new refrigerants using Hydro carbons or hydrocarbon mixtures. The present paper presents the experimental investigations on the domestic refrigerator using two different hydrocarbon mixtures, viz., R50/50(R290/R600a) and R436Awith mass fraction of 56/44of R290 and R600a. The experiments are conducted by changing the refrigerant charge (mr) and length of capillary tube (LC) at different evaporator temperature (Te).Continuous consecutive lyand cycling tests are performed on the refrigerator under steady state situations. The pressure at the inlet and outlet of the compressor are note down and evaluated as well as the temperature readings can be observed at various positions in the refrigerator. And also the pull down time is noted for the three different refrigerants for varying refrigerant charge and length of capillary and graphs are plotted. The results show that the design temperature of -150C(according to IS1476 part1) and pull down time of 90 minutes are achieved by using 70g of R436A with L=4.5M,for CARE is achieved at pull-down time of 100minutes with 70g and L=5m and R134a achieved as 110minutes with 100g and 4m. The performance has shown that the R436A refrigerant can be the best substitute to R134a.