Quantification of liquid refrigerant distribution in parallel flow microchannel heat exchanger using infrared thermography

This paper presents a method to quantify the distribution of liquid refrigerant mass flow rate in a parallel flow microchannel heat exchanger from the infrared images. Quantification is achieved by building the relationship between the liquid mass flow rate through each microchannel tube and the air-side capacity calculated from the infrared measurement of the wall temperature. After being implemented in a heat exchanger model, the quantification method is validated against experimental data. This method can be used for several types of heat exchangers: evaporators, condensers, gas-coolers, etc., also it can be applied to various heat exchanger designs: different inlet/outlet locations, different flow configurations, etc.