Analysis of inlet temperature, pressure, and channel design effect on cryogenic methane evaporation in minichannel PCHEs

Abstract

The thermal-hydraulic performance of Printed Circuit Heat Exchangers (PCHEs) with minichannels plays a crucial role in liquefaction and vaporization processes within the energy sector and diverse industrial applications, serving as a pivotal component in the secure treatment of cryogenic fluids. Computational fluid dynamics (CFD) simulation was needed to do systematic analysis for the development of thermal hydraulic performance PCHEs in cryogenic applications. In this study, CFD simulations using the Volume of Fluid (VOF) method were employed to systematically investigate two-phase flow simulation in minichannel PCHEs. The effects of fluid pressure and inlet temperature on the cryogenic methane evaporation was studied, showing that lower inlet pressure and temperature increased evaporation rates. Nucleate boiling dominated at 0.1 MPa, while convective boiling occurred at higher pressures (0.7–1 MPa). Geometric analysis showed that smaller channel (D = 0.884 mm) enhanced heat transfer but caused higher pressure drops, while larger channels (D = 2–3 mm) reduced pressure losses and increased vapor generation, though with lower heat transfer coefficients. Furthermore, new zigzag channel design, based on previous research, was proposed to enhance evaporation by promoting higher turbulence, mixing, and heat transfer rates compared to straight channel. This study also reviewed the effects of various working fluids and channel geometries including channel shapes (zigzag, straight) and cross-sectional profiles (rectangular, circular, semicircular) on cryogenic evaporation performance. These results highlight how optimizing pressure, inlet temperature, and channel geometry can enhance vapor quality, heat transfer, and pressure drop performance in minichannel PCHEs for cryogenic applications.