Enhancement of Energy Parameters for Refrigerants Used instead of R22 by Arranging Capillary Tube Length

AbstractThe capillary tube is used in most air-conditioning systems due to its low cost and not requiring sensitivity. In this study, the improvement of energy parameters was examined by adjusting the length of capillary tubes as well as using alternative refrigerants for an air conditioner operating with R22. The cooling capacity, coefficient of performance (COP), and electricity consumption results as well as pressure and temperature measurements in the system were investigated for the available length of capillary tube in the unit and shorter lengths (i.e., cutting 20 and 40 cm from the original length, respectively) with R422D and R417A refrigerants at ambient temperatures of 25–45°C. Evaporator inlet pressure and evaporation temperature increased as a result of decreasing the capillary tube length. According to the results of study, the most suitable capillary tube length may be suggested as 80 cm, which developed an increase in COP by about 0.9–2.8% compared to the original capillary tube length for studied ambient temperatures using R422D and R417A.