关键词: 超临界流体, 液化天然气, SCV, 数值模拟, 传热, 蛇形换热管

Abstract:

Submerged combustion vaporizer (SCV) is widely used in LNG receiving terminals. In order to study the flow and heat-transfer characteristics of supercritical LNG in SCV coil tubes, a three-dimensional computation model is established to analyze the influence on fluid temperature and local heat transfer coefficient, base on pressure, heat flux, inlet velocity and variation of physical properties. The results indicate that the local heat transfer coefficient first increases and then decreases along the flow direction, and the maximum occurs at the pseudo-critical temperature. Due to the secondary flow, the coefficient of local heat transfer increases abruptly. In the range of operational pressure, the maximum of local heat transfer coefficient decreases with increasing tube-side pressure. As the heat flux increases, the maximum of local heat transfer coefficient increases and appears earlier, and drops faster after the maximum. Higher heat flux deteriorates the heat transfer. The maximum of local heat transfer coefficient increases and appears later as the inlet velocity increases. The numerical simulation study provides scientific guidance to the design of SCV.

Key words: surpercritical fluid, LNG, SCV, numerical simulation, heat transfer, coil tubes