Numerical simulation on heat transfer and flow of supercritical methane in printed circuit heat exchangers

Abstract

The printed circuit heat exchanger (PCHE) is a novel type of heat exchanger in liquefied natural gas (LNG) industry. The gasification pressure of LNG in PCHE could exceed the critical pressure of methane, the main component of LNG. This paper established a series of three-dimensional models of PCHE units. The effects of structural parameters and channel shapes on the thermal hydraulic performance are studied. And new correlations to calculate the Nusselt number and Fanning factor of supercritical methane in straight and zigzag PCHEs are developed. For straight PCHE, the most influential geometrical parameters are the spacing between two adjacent channels in the plate and the diameter of the semicircle, which have been taken into account in the new correlation. For zigzag PCHE, the inclined angle has impact on both heat transfer coefficient and pressure drop while the pitch number only influences the pressure drop. Considering these factors, the new correlations for zigzag PCHE are modifications from the new straight PCHE correlations.