Effects of 3-way valve faults and capillary tube clogging on the dynamic behavior of compressor power consumption during start-up operation of a household refrigerator-freezer

Abstract

To expedite the quality inspection (QI) on household refrigerator-freezer (HRF) production lines, rapid and accurate fault detection and diagnosis during the brief start-up operation period are essential. This requires a thorough understanding of the HRF’s dynamic behavior during this phase and the selection of a suitable fault indicator from the measurable parameters. This study investigates the dynamic behavior of compressor power consumption during the HRF’s initial 20-minute start-up operation under specific failure conditions, such as blockage and leakage of the 3-way valve, and capillary tube clogging. These conditions were examined through six distinct failure scenarios. The findings reveal that alterations in the refrigerant path due to these faults are immediately reflected in the compressor power consumption, both quantitatively and qualitatively. The compressor power data, serving as a fault detection indicator, displayed clear changes resulting from modifications in the refrigerant passage due to the faults examined. However, it was not possible to determine the exact location of the refrigerant passage blockage, whether it was the 3-way valve or the capillary tube, based solely on the compressor power data. This highlights the need for an auxiliary fault indicator.