Experimental investigation on the performance of air cooler under frosting conditions

Evaluation of heat transfer performance of the air cooler under frosting conditions is of great importance for the refrigeration industry. In this paper, effects of frost growth on the performance of the air cooler have been studied with an experimental air cooler of industrial size with different fin spacings, i.e., 6, 8 and 10 mm. Results showed that factors affecting the heat transfer performance of the air cooler include the evaporation temperature, the frost height, the fin spacing and the air velocity. The overall heat transfer coefficients based on a logarithmic mean temperature difference (LMTD) and the energy transfer coefficients based on a logarithmic mean enthalpy difference (LMED) were calculated. As the frost accumulated on the air cooler, the overall heat transfer coefficient and energy transfer coefficient will drop gradually