LNG绕管式换热器壳程对流换热数值模拟

Numerical simulation on the convective heat transfer at the shell pass of spiral-wound LNG heat exchanger

绕管式换热器是天然气液化的核心设备,其换热性能的优劣严重影响液化工艺水平。基于绕管式换热器的结构及特性,采用Fluent软件,对LNG绕管式换热器壳程单相混合冷剂的对流换热进行了数值模拟。结果表明:换热管管径是影响壳侧换热的重要因素,壳侧换热系数、壳侧冷剂压降均随换热管管径、壳侧冷剂质量流量的增大而增大。模拟结果与已有实验值的偏差均控制在20%以内,二者具有较高的匹配性,说明采用新建立的数值模拟模型用于绕管式换热器换热性能研究具有可行性。

Spiral-wound heat exchanger is the key equipment for the liquefaction of natural gas, and its heat transfer performance has a significant effect on the level of liquefaction process. In this paper, the convective heat transfer of singlephase mixed refrigerant at the shell pass of spiral-wound LNG heat exchanger was numerically simulated by Fluent software based on the structure and features of spiral-wound heat exchanger. It is indicated that the diameter of heat exchange tube is one of the important factors influencing the shell-side heat transfer. The shell-side heat transfer coefficient and the shellside refrigerant pressure drop increase with the increase of the tube diameter and the mass flow of shell-side refrigerant. The deviation between the experimental value and the simulation result is lower than 20%, indicating that both of them are more matched. In conclusion, this newly established numerical simulation model is feasible for studying the heat transfer performance of spiral-wound heat exchanger.