Flow and heat transfer characteristics of printed circuit heat exchangers with different channel structures

In order to analyze and compare the influence of channel structure of heat exchanger on its flow and heat transfer characteristics more standardized and accurate, numerical models were established based on the same unit volume heat transfer area and channel length through Fluent steady-state simulation using supercritical LNG as the working medium, for the printed circuit heat exchangers (PCHE) with straight, Zigzag, S-shaped, and airfoil channels. In this way, the heat transfer and pressure drop performance of 4 types of channel structure at diferent inlet temperatures, mass flow rates and operating pressures, as well as the development laws of local flow and heat transfer characteristics, were analyzed. The results indicate that the channel has better heat transfer characteristics at high inlet temperature, large mass flow rate and low operating pressure. Among the four channels, the Zigzag channel has the strongest heat transfer capacity, the S-shaped channel has the highest pressure drop, and the airfoil channel has the best integrated heat transfer performance. In addition, the heat transfer per unit area of the fluid in the channel may fluctuate and rise sharply near the quasi-critical point, and the pressure drop along the way may increase in diferent forms depending on the flow rate and the channel structure. In general, the research could provide theoretical basis for the selection of heat exchanger for the floating LNG facilities and the improvement of internal structure of the channel.