基于板式换热器的天然气冷却模拟与实验研究

Numerical simulation and experimental investigation for natural gas cooling process based on BPHE

结合实际工程项目,针对某新型天然气冷箱液化流程中的三台钎焊板式换热器,采用双通道耦合换热模型,以分段线性插值法计算天然气物性,基于FLUENT软件进行了天然气冷却换热过程的CFD数值模拟仿真,并开展了该新型冷箱的实验测试研究。将数值模拟计算结果与HSYSY工艺流程设计值以及实验测试结果进行对比。结果表明,数值模拟计算结果与HSYSY设计值平均误差为4.94%,证明了采用CFD数值模拟方法对HYSYS工艺流程设计与设备选型进行校核具有一定的参考价值。数值模拟计算结果与实验测试结果平均误差为7.78%,证明了数值模拟仿真所采用的简化假设、换热模型以及求解方法对于板式换热器天然气冷却换热过程是合理的。

In the present paper,the CFD numerical simulation by FLUNT software as well as experimental investigation were conduced based on a practical engineering project,using three brazing plate heat exchangers in a new designed cold box for natural gas liquefaction.In the numerical simulation,dual channel coupled heat transfer model was used for calculation and piecewise linear interpolation was adopted for thermophysical properties fitting of natural gas.The corresponding experimental measurements were carried out for the new cold box.Comparing the numerical simulation with the HYSYS process design and experimental data,the results show that 4.94% error between the simulation and process design,and 7.78% error between the simulation and experiments.It indicates that CFD method has certain reference value for the preliminary check of HYSYS process design and equipment selection.In addition,the simplified assumptions,heat transfer models and solving methods used in the numerical simulation are suitable for the cooling heat transfer process of the natural gas in the brazing plate heat exchanger.