Effect of the Suction Pipe Material in a Non-adiabatic Capillary Tube on Refrigeration System Performance

This study experimentally investigated the influence of a suction pipe material of a non-adiabatic capillary tube commonly employed as an expansion device in a majority of household refrigerator-freezers on refrigeration system performance. An experimental refrigeration system was constructed utilizing system components from an actual domestic refrigerator using R-600a as a refrigerant. Two non-adiabatic capillary tubes that were identical in shape and joint method but with different suction pipe materials (copper vs. aluminum) were employed as test samples. These capillary tubes were alternately installed and subjected to identical operating conditions for testing. Upon utilization of both non-adiabatic capillary tubes, performance indicators such as refrigerant mass flow rate, cooling capacity, and coefficient of performance showed no significant disparities. Consequently, this study demonstrates that using either capillary tube to an actual household refrigerator-freezer would not result in any substantial differences in the appliance’s power consumption.