Study on the frosting phenomena between concavity and convexity plate under forced convection-analysis of frost layer growth

In recent years, electric vehicles have been actively developed, and to use heat-pump system is meaningful for air conditioning system for electric vehicle. But frost formation of external heat exchanger becomes a problem under the heating cycle. To improve of heat exchange performance and to inhibit frost formation for heat pump system, fin-less heat exchanger is proposed. In this study, we investigated basic characteristic of frost formation of the flow path between flat plate with concavity and convexity under forced convection. Test section is a flow path that is placed opposite to a flat plate having a periodic concavity and convexity groove on the surface. Experiment was conducted using structure of concavity and convexity as a parameter. By visualizing the frost formation, the relationship of time to passage blockage and structure of concavity and convexity became clear. And it is possible to optimize of concavity and convexity.