LNG储罐液氮预冷数值模拟研究

摘要

Evaporation-boiling phase change model is adopted to conduct numerical simulation of liquid nitrogen phase change by using the mixture multiphase flow model in Fluent software,and the overall temperature field of LNG storage tanks under different inlet flow velocities are calculated and analyzed,and then the optimum flow velocity for storage tank precooling can be obtained.The result indicates that the temperature drop rate ofLNG storage tanks shall not be more than 5 K/h,so the liquid nitrogen precooling velocity shall not too high,and the inlet flow velocity of 2 m/s can be adopted when the tank temperature drops to below 160 K.The study result provides references for the experiment and actual application of LNG storage tanks.%采用Fluent多相流混合模型,选用蒸发—沸腾相变模型实现了液氮相变数值模拟,对不同进口流速下LNG储罐整体温度场进行了计算与分析,进而得到储罐预冷的最佳流速.结果表明,为保证规范设计要求,LNG储罐温降速率不应超过5 K/h,因而液氮预冷速度不应过大,储罐温度至少要降低到160 K以下才能采用2 m/s的入流速度.此研究成果为LNG储罐的试验及实际应用提供了借鉴和参考.