Numerical study on flow and heat transfer characteristics of airfoil printed circuit heat exchangers
Printed circuit heat exchanger(PCHE),as a new type of efficient and compact micro-channel heat exchanger,has been widely used in supercritical carbon dioxide(SCO2)Brayton cycle.The thermal and hydraulic performance of SCO2 in airfoil PCHE channel was analyzed by numerical simulation.With the improvement of fin size,the surface heat transfer coefficient and comprehensive performance are improved,and with the increase of variation degree,the surface heat transfer coefficient and comprehensive performance are further improved.When the Angle of attack is changed to change the fin orientation,the surface heat transfer coefficient and comprehensive performance are higher than that when the angle of attack is 0°,and the surface heat transfer coefficient and comprehensive performance are further improved with the increase of change degree.Slotting in the center of the fin to change the shape of the fin,slotted fin arrangement can reduce the friction factor,improve the flow performance,but the comprehensive performance is reduced.The orthogonal test with the three structural parameters of fin size,orientation and shape shows that the dimensionless slot width of fin has the greatest influence on the flow heat transfer performance.In the sample range,the structure with fin expansion ratio of 1.4,angle of attack of 20° and no slot has the best comprehensive performance.The analysis of flow and heat transfer performance of PCHE with different airfoil structures can provide reference for SCO2 cooling theory research and PCHE typical engineering application.
supercritical carbon dioxideprinted circuit heat exchangernumerical simulationflowheat transfer
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