A Study on the Refrigerant Distribution in a Parallel Flow Micro-Channel $CO_2$ Evaporator

평행류형 마이크로채널 이산화탄소 증발기에서 냉매분배에 관한 연구

In this study, the distribution of $CO_2$ in an evaporator with 10 parallel micro channel aluminum tubes are experimentally investigated. Each tube has 6 circular micro channels with a diameter of 0.8mm. The tubes are heated with electric resistance wires, and the distribution of $CO_2$ into each tube is investigated by measuring the outer wall temperature. The outer wall temperature was found to be higher at the exit part of the top tube. It is thought that the $CO_2$ vapor at the upper part of the header reduces the mass flow rate of $CO_2$ into the top tube.