STUDY ON THE FROSTING PHENOMENA BETWEEN CONCAVITY AND CONVEXITY PLATE UNDER FORCED CONVECTION: Analysis of Frost Layer Growth

摘要

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