2014 Volume 31 Issue 2 Pages 91-98
In the motor vehicle industry, the familiarization of electric vehicle (EV) is accelerating. High efficiency and securement of the heating are requested for the air conditioning equipment for vehicles. The most effective way to heating is using heat pump, but the decreasing of heat transfer coefficient and the pressure drop caused by the frost of evaporator could be a big problem. Therefore the inhibition of frost in evaporator is especially required. The performance increase of the finless heat exchanger is expected, because it can flush the dew condensation water. In this study, we aimed to establish the evaluation technique of the defrosting characteristic. About frost growth the weight of frost was measured and frost growth was observed by micro CCD camera. The fundamental characteristic of the heat transfer coefficient, the pressure drop, and the frost growth was grasped. From the experiment, the block of flow channel by frost was seen in the angle part of upper position of concavity and convexity plate (test section).
