超临界LNG在螺旋形微通道中的流动传热特性

Flow and heat transfer of supercritical LNG in spiral microchannel

由于液化天然气(LNG)稳定、安全、体积小,通常将天然气液化后进行运输。LNG汽化后才能使用或输入管道,因此换热器作为汽化LNG的关键部件而被广泛应用。换热器内部由大量微细通道组成。本文主要针对螺旋形微细通道内超临界LNG的流动情况进行分析,对比不同螺距螺旋形流道的流动换热性能,随着螺距的减小,换热性能提升而流动性能下降。与直流道相比,采用合适螺距的螺旋形流道可以显著提升换热性能而对流动性能的影响相对较小。通过计算不同质量通量、热流密度下螺旋形流道的流动换热性能,讨论了螺旋形流道中,能实现较好的流动换热性能的质量通量和热流密度。

As liquefied natural gas(LNG) is stable, safe and small, it is usually transported after liquefaction. LNG can only be used or put into pipeline after vaporization, so heat exchanger is widely used as the key component of vaporizing LNG. The heat exchanger is composed of a large number of micro channels. This paper mainly analyzes the flow of supercritical LNG in spiral microchannel, and compares the flow and heat transfer performance of spiral microchannel with different pitch. With the decrease of pitch, the heat transfer performance is improved, but the flow performance is decreased. Compared with the straight channel, the spiral channel with appropriate pitch can significantly improve the heat transfer performance, but has less effect on the flow performance. By calculating the flow and heat transfer performance of spiral channel with different mass flux and heat flux, the mass flux and heat flux which can achieve better flow and heat transfer performance in spiral channel are discussed.