PERFORMANCE STUDY OF A DIMPLED-PROTRUDED AIR-TO-AIR PLATE HEAT EXCHANGER

摘要

In the present study, the overall heat transfer coefficient, friction factors, and effectiveness of a dimple-protrusion air-to-air counter-flow plate heat exchanger have been measured at low Reynolds number (500 ＜ R_e＜ 4,000). The heat exchanger consists of 4 channels per flow direction built using 1 mm aluminum plates. Dimples are specially arranged such that protrusions are opposed for applications that require structural support to withstand high pressure difference between the two fluids. A maximum heat enhancement level of 3.2 was obtained with a penalty of increased friction factor by 9 times which leads to a maximum performance factor of 1.5. The effectiveness obtained was found to be almost independent of Reynolds number on most tested Re. A detailed uncertainty analysis has been performed to determine the uncertainty in the results.