The difference in cheracteristics between parallel and counter flow type heat exchangers with frosting.

On heat exchangers with frosting, the characteristics changes with time due to the growth of a frost layer, which depends on frosting conditions. In this paper, the emperical correlations for initial conditions needed to predict frost formation based on the structural model were presented and thay enabled to predict the frost growth without using any experimental data under various frosting conditions. The difference in characteristics between parallel and counter flow type heat exchangers with frosting has been studied experimentally and theoretically. It was found that with growing of a frost layer, the average thermal resistance on counter flow type became larger in comparison of that on parallel flow type and the temperature efficiency for counter flow type gradually approached that for paralell flow type.