Digital particle image velocimetry measurement of inner flow field in cooling chamber of frost-free refrigerator

A transparent model based on a BCD-190W type frost-free refrigerator was constructed with organic glass, and the experiment system for measuring the air flow characters in the cooling chamber of the model was built. Using digital particle image velocimetry (DPIV) technology, the mean velocities distributions on the typical 2-D zones in the cooling chamber of the model were measured. The experiment results show that the air flow velocities and air flow rates at the supply-air openings were non-uniform. The air flow velocities at the openings in the top chest were the largest in the four chests, and those in the fourth chest were somewhat lower. Moreover, the air velocities at the openings in the second and third chests were less than 0.1 m/s, and thus the flow rates could not meet the function requirement of the chests. Through the analysis of the velocities distributions, the practicability of using DPIV system to measure the flow characters in the chests of the model were verified, and the shortages of the air velocities and flow rates design were discovered. The measurement results also indicate that the resistance and flow rates design for the air flow ducts are the key factors for the refrigerator design.