Heat transfer and residence time distribution of liquid flow in direct contact evaporation heat exchanger

To enhance the heat transfer of liquids, a new gas-liquid-liquid three-phase exchanger based on the SK elements was proposed for utilization in energy recovery. Visual experimental investigation of the particle transport characteristics was carried out. The effects of the flow velocity, pipe diameter, arrangement, number and length-to-diameter ratio of elements on the mean residence time (MRT) were studied. An analysis of the velocity distribution of the particles of the operated cell through the SK element was performed. A pentane-water direct contact evaporation heat transfer experiment was carried out to investigate the effect of the SK elements on the heat transfer performance. The results indicated that the SK elements reduced the evaporation height, and the volumetric heat transfer coefficient was more than two times greater than that in the heat exchanger without the SK elements.