超临界LNG高压气化器微通道结冰研究OA

Aiming at the freezing problem on the hot side of the high-pressure vaporizer,a core component of the Fuel Gas Supply System(FGSS)for dual-fuel power vessels,a three-dimensional numerical model with dual channels was established for the high-pressure vaporizer to simulate the flow and heat transfer processes of supercritical liquefied natural gas(LNG)and 50%ethylene glycol aqueous solution.Parametric analyses were carried out to investigate the effects of inlet temperature and flow rate on the hot-side freezing behavior for both the cold side(supercritical LNG)and the hot side(50%ethylene glycol aqueous solution).The numerical results show that under the 1∶1 alternating arrangement of cold and hot plates,freezing is prone to occur in the outlet region of the hot side,especially at the channel corners,leading to a decrease in the Nusselt number(Nu)and a 16%increase in flow resistance in the frozen sections.The reduction in inlet velocity(from 3.0 m/s to 0.5 m/s)and temperature(from 328 K to 308 K)on the hot side,as well as the increase in inlet velocity(from 0.5 m/s to 2.5 m/s)and the decrease in temperature(from 130 K to 110 K)on the cold side,all contribute to the thickening of the ice layer.Severe freezing occurs when the inlet velocity of the cold side is higher than that of the hot side,with the ice layer occupying up to 81.6%of the outlet channel cross-sectional area,which significantly elevates the risk of freeze blockage in the heat exchanger.The quantitative analysis model for freezing behavior under the coupling effect of multiple parameters established in this study provides a theoretical basis for the optimal structural design of anti-icing configurations for LNG high-pressure vaporizers.