TO-98-18-2 -- An Experimental Study on New Egg-Crate Type Evaporators in Domestic Refrigerators and Freezers PDF

This paper presents experimental results of the heat transfer performance of new egg-crate type evaporators that are becoming popular in vapor compression cycle-based modern refrigerators and freezers. These forced flow, multiple finned evaporators are preferred in the local industry over the older roll-bonded designs due to efficiency and cost considerations. Extensive testing was done, and experimental data were gathered on evaporators of three different sizes at three airflow rates using a closed-loop test rig built for the purpose. This has led to the development of a novel approach of measuring low air velocities as encountered in domestic refrigerators. A correlation has been developed for the heat transfer performance of these evaporators following the j-Colburn factor analysis. The correlation relates the j-Colburn factor, a nondimensional heat transfer grouping of the Nusselt number, Reynolds number, and Prandtl number to the Reynolds number and finning factor.

Units: SI