Air-Side Thermal Behavior of Parallel-Plate Evaporators. Part I: Sensible Heat Transfer

An experimentally validated mathematical model is presented to simulate the thermal behavior of a new type of roll bond parallel-plate evaporators intended for use in domestic "no-frost" refrigerators. An open-loop wind-tunnel calorimeter was used to generate experimental data on the air-side thermal conductance for air flow rates ranging from 17 to 85 m3/h. The semi-analytical mathematical model consists of dividing the evaporator in several differential control volumes involving the air, plate and coolant domains and solving the coupled energy equations for the three domains to generate spatially resolved temperatures in the air, aluminum plate and refrigerant (coolant). Good agreement was obtained between the model results and the experimental data (80% of the data point predicted to within +/- 5% error bands) without the introduction of new empirical parameters. In Part II, the model is extended to deal with frost accretion on the plates.