Investigations on thermal–hydraulic performance and entropy generation characteristics of sinusoidal channeled printed circuit LNG vaporizer

Liquefied natural gas (LNG) is a clean energy source that shows great potential for further development. In the production and transportation process of LNG, heat exchanger is an essential device that conducts the liquefaction and vaporization operations. With the booming development of floating LNG (FLNG) technology, higher requirements have been put forward for heat exchangers due to the limited space and rolling conditions. Printed circuit heat exchanger (PCHE), as a typical micro-channel heat exchanger, is considered an ideal candidate for floating storage and regasification unit (FSRU) due to preeminent compactness and efficiency. In this study, a three-dimensional model of sinusoidal channel-based printed circuit LNG vaporizer is established. The thermal–hydraulic and entropy generation characteristics of the vaporizer with various waviness factors, including the amplitude and wavelength, are numerically investigated. The results indicate that larger amplitude or smaller wavelength results in the heat transfer augmentation with greater pressure drop and minor overall entropy generation. As the secondary flows with boundary layer destructions caused by sinusoidal channel structures enhance the local heat transfer, the entropy generation concentrates at the near-wall region. For a sinusoidal channeled printed circuit LNG vaporizer, moderate amplitude and wavelength are more reasonable to obtain better comprehensive performance, and the thermal–hydraulic performance and irreversible energy loss should be considered simultaneously.