Experimental study of frost formation on a fin-and-tube heat exchanger by natural convection

摘要

This paper presents an experimental study of frost growth on a fin-and-tube heat exchanger by natural convection. Experiments are carried out for refrigerant mean temperature of -10 degrees C, -15 degrees C and -20 degrees C, ambient temperatures between 20 degrees C and 30 degrees C and relative humidity varied from 50% to 70%. The results include changes of frost thickness and its impact on heat transfer rate under different environmental condition. Frost growth depends on time and location along the fin and tube heat exchanger. Frost thickness varies due to changes of air velocity, temperature and concentration boundary layers. The heat transfer rate and frost growth show strong dependence on refrigerant mean temperature, ambient air temperature and relative humidity. According to the measurements, some practical empirical correlations of frost growth and heat transfer are presented in terms of relevant dimensionless parameters. (C) 2014 Elsevier Ltd and IIR. All rights reserved.