Effects of capillary tube clogging on the energy consumption of a household refrigerator-freezer with a dual evaporation circuit

Abstract

Comprehensive experimental results for real household refrigerator-freezers under faulty conditions are scarce in the literature. This study investigates the effects of capillary tube clogging, a specific fault condition, on the dynamic performance and energy consumption of household refrigerator-freezers. Using a household refrigerator-freezer with a dual evaporation cycle circuit, a series of experiments were conducted at various capillary clogging ratios to simulate the fault condition known as capillary clogging. The results demonstrate a significant decrease in system performance and energy consumption, along with an increase in compartment air temperature when the capillary tube is clogged. As a result, the system fails to achieve its intended functionality. Particularly, when the degree of clogging reaches 84.1%, the compartments cannot maintain their target temperatures, regardless of the operation mode. Both cooling capacity and power consumption decrease with the increasing clogging ratio for each operation mode. As a result, the coefficient of performance (COP) values also decrease, as the reduction rate in cooling capacity exceeds the reduction rate in power consumption.