The transient state modeling and optimization of refrigerant charge amount for a household refrigerator

Abstract

Energy consumption regulation of household refrigerator has been continuously strengthened worldwide. In Korea, energy efficiency rating labeling was enforced from 1992. According to data from the Korea Energy Management Corporation (KEMCO), energy consumption of refrigerators has been reduced 59% over 15 years. Because of that, most refrigerator manufacturers are seeking ways to improve thermal and electrical performance of their products. In general, researching and development method of refrigerator is trial and error procedure, which is time consuming and costly. Hence, numerical analysis represent an essential tool to improve time and cost. Therefore, a study for the numerical simulation of the refrigerator has been conducted actively. In this study, experiments were conducted together with the numerical simulation to find the refrigerant charging amount of minimizing the power consumption of household refrigerator, which has capillary tube with heat exchanger. The experimental data were obtained in refrigerant charge range from 80 g to 125 g at ambient temperature of 25℃. According to the experimental data, the power consumption of household refrigerators has been minimized at the refrigerant amount 104g. The numerical simulation was computed under the same condition of the experiments by finite difference method. The numerical data showed that power consumption was minimized at refrigerant amount 98 g. Numerical simulation result was compared with experimental data, and it was found that optimal refrigerant charge amount was well predicted by the model.