EFFECT OF INLET CONFIGURATION ON DISTRIBUTION OF AIR-WATER UPWARD FLOW IN A HEADER OF A PARALLEL FLOW HEAT EXCHANGER

The effect of inlet con figuration (parallel, normal, vertical) on flow distribution in a parallel flow heat exchanger consisting of round headers and ten flat tubes is experimentally studied using air and water. The effects of tube protrusion depth as well as header mass flux, and quality are investigated for upward flow con figuration. It is shown that best flow distribution is obtained for vertical inlet con figuration, followed by normal inlet and parallel inlet con figuration. For upward flow, significant portion of the water flows through the rear part of the header. As protrusion depth increases, more water is forced to the rear part of the header. The effect is most significant for parallel inlet, followed by normal and vertical inlet. The effect of mass flux or quality is opposite to that of the protrusion depth. Possible explanation is provided from flow visualization results.