Simulation Of Propane Condensate Flow And Heat Transfer In A Printed Circuit Plate LNG Gasifier

The global carbon emission reduction process has accelerated the pace of China’s energy transition,and with the introduction of "carbon neutral,carbon peak" and other policies,clean energy will flourish.Natural gas will play an important role in energy transition because of its advantages of high energy and low carbon.In the FSRUs,the high efficiency and compact printed circuit plate LNG gasifier is the core component of regasification.Currently,researches on LNG gasifiers mainly focus on the supercritical methane side.However,the condensate flow on the propane side,as the intermediate heat transfer medium,has an important impact on the heat transfer and pressure drop performance of the gasifier.In order to avoid the influence of complex structure and uneven heat flow,a single channel printed circuit plate heat exchanger was used to simulate the flow of propane condensation on the hot side of LNG gasifier.Firstly,a numerical simulation was carried out for the PCHE channel,and the influence of operating parameters on the flow heat transfer of propane condensation was studied from the perspectives of local condensation heat transfer coefficient,irreversible entropy production,vortex structure distribution.The results show that the condensation heat transfer coefficient of propane in PCHE increases first and then decreases along the flow direction.Meanwhile,with the increase of inlet mass flow rate,inlet dryness and inlet temperature,the average condensing heat transfer and pressure drop increase.However,with the increase of the absolute wall heat flux and outlet pressure,the average condensing heat transfer coefficient and pressure drop decrease.In addition,the existence of vortex structure will have a positive effect on heat transfer,and the distribution of vortex structure is corresponding to the condensing flow pattern.Secondly,the influence of the channel structure on the flow heat transfer of propane condensate in PCHE was studied.The results show that increasing the turning angle and decreasing the single intercept process can both increase the overall heat transfer and pressure drop,and decreasing the channel radius can increase the average condensing heat transfer and pressure drop.Finally,the variation of the condensate flow pattern of propane in PCHE and its effect on heat transfer were studied.The results show that in the flow process,the condensing flow pattern basically presents annular flow.Under low mass flow rate and low dryness,there will be a change of wave annular flow to jet flow,and some conditions will produce elastic flow.The local condensing heat transfer coefficient of different flow patterns is different,among which,the local condensing heat transfer coefficient of the smooth annular flow is the largest.