착상 조건 시 마이크로채널 열교환기 착상 특성

Present study investigated frost characteristics and thermal performance of micro-channel heat exchanger using R-410A under frosting condition. Local and average frost surface temperature, blockage ratio(BR), and heat transfer rate of the vertically installed micro-channel evaporator were measured under frosting condition. Test condition was set at dry bulb air temperature of 2℃ and wet bulb air temperature of 0.44~1℃, air velocity of 1.5~2.5m/s, inlet quality of refrigerant of 0.2, mass flow rate of R-410A of 0.354~0.919kg/s, and inlet refrigerant temperature of -2.5℃. Non-uniform frosting over the frosted surface was observed over the whole test range. Frost characteristics including frost pattern and heat transfer rate of micro-channel heat exchanger were measured under frosting conditions. Non-uniformity of frost growth on the heat exchanger affected frost delay as well as decrease of the thermal performance.