LNG绕管式换热器壳侧单相传热模型的优化

天然气液化工艺中绕管式换热器的壳侧热力计算是当前亟待解决的问题之一,针对低温工况下壳侧传热模型的研究尚不多见,需要选取出适用的传热模型准确计算传热系数,为天然气液化工艺中绕管式换热器的设计选型和热力校核提供依据。本文比较分析了现有壳侧单相传热模型的优缺点,结合绕管式换热器壳侧低温实验数据,筛选出了适用于天然气液化预冷段的壳侧传热模型,并进行了优化。结果表明:对于天然气液化预冷段的壳侧传热系数计算,Abadzic传热模型计算精度最高、偏差范围最小、适用性最佳;Abadzic传热模型粘度修正后计算精度提高约50%,天然气液化预冷段的粘度修正系数可估算为1.05。

Optimization of Shell-side Single Phase Heat Transfer Correlation for Coil-wound LNG Heat Exchanger

Shell-side thermodynamic calculation of coil-wound LNG heat exchanger is one of the important problems to be solved. Shell-side heat transfer models on low-temperature conditions are mentioned on very few occasions. It is a necessity to choose the best thermodynamic calculation correlation on cryogenic working conditions. The existing shell-side single phase heat transfer models were evaluated. Using the shell-side measurement data of coil-wound LNG heat exchanger on low-temperature conditions, this paper got the best shell-side heat transfer model for the pre-cooling stage of natural gas liquefaction process, and optimized this model. In conclusion, Abadzic heat transfer model gets the best accuracy and the strongest applicability, so it is properly selected for the pre-cooling stage of natural gas liquefaction process. The accuracy can be improved about 50% by the use of viscosity correction, the factor of which in the pre-cooling stage should be estimated at 1.05.