Impact of heat infiltration on the cooling capacity evaluation of an evaporator for household refrigerator-freezers with a non-adiabatic capillary tube

Abstract

This study experimentally evaluates the cooling capacity of an evaporator in household refrigerator-freezers, typically scaled in hundreds of Watts, and investigates the impact of heat infiltration from the environment. Despite the scarcity of both quantitative and qualitative research in this area, this study provides data from a lab-scaled vapor compression refrigeration system that mimics a real-world side-by-side refrigerator-freezer. Experiments were conducted under conditions reflecting the household refrigerator-freezer, yielding 74 data points under quasi-steady state conditions. Despite careful insulation, heat infiltration from the ambient to the refrigerant flow in the evaporator occurred due to the significant temperature differential, impacting the cooling capacity evaluation fatally with a heat balance error of 26%. However, when considering the effects of heat infiltration, the error in the evaporator heat balance dropped to 6% significantly. The findings highlight the sensitivity of evaporator’s cooling capacity, less than 300 W, to external thermal factors during empirical evaluation. This study underscores the challenges of heat infiltration and the importance of considering such factors when assessing evaporator cooling capacity. The provided comprehensive analyses significantly contribute to the experimental prototyping of evaporators, emphasizing the need to account for external thermal influences during the evaluation process.