Performance evaluation of capillary-assisted plate-type evaporator with machined surfaces

This study explores the use of Cu plates with machined or finned external surfaces in a partially flooded evaporator. The machined surfaces (finned/grooved surfaces) are intended for the enhancement of heat transfer by means of capillary-assisted evaporation. This concept has possible applications in absorption and adsorption systems. Evaporation heat transfer tests on the evaporator plates are conducted at saturated water vapor pressures ranging from 6 to 8 Torr. The evaporator has a single-pass setup with a welded heat transfer plate. The influence of immersion depth and hot water velocity as well as evaporation pressure are investigated. Results show that heat transfer rate varies with the variation of the immersion depth. Also, the heat transfer performance of the plate with finned surfaces was considerably higher than that of the plain plate. Moreover, it is expected that when the fin/groove sizes are varies the capillary-assisted evaporation performance would also vary.