相变换热混合工质板翅式换热器流动与传热数值模拟

Numerical simulation of fluid flow and heat transfer of refrigerant mixture for plate-fin exchanger with phase change

采用由SRK方程计算得出的混合工质物性参数,将具有相变两相流体物性分三部分处理,得出混合工质分段物性数据拟合曲线,并输入FLUENT软件的材料物性数据文件中,作为数值模拟物性参数数据。在上述物性数据处理的基础上,对混合工质天然气液化装置中换热器采用分段方式进行稳态数值模拟研究,得到沿长度方向一定温度下传热系数、压力梯度的变化曲线。通过与MUSE软件数据比较,计算结果有一定合理性,所得结论为有相变换热的混合工质低温板翅式换热器的设计和优化提供一定参考。

The thermal properties of refrigerant mixture were calculated with SRK equation. The temperature range of twophase fluid with phase change was divided into 3 sections and the piecewise curve of the mixtures was formed. The data of physical properties were typed to FLUENT database and used for numerical simulation. Based On data analysis above, the heat exchanger in natural gas liquefaction system was simtdated in the piecewise mode and the curve of heat transfer coefficient and pressure gradient vs temperature was formed. Compared with MUSE software, the mechod is reasonable. The desing and optimization of heat exchanger can be used as the guidance on the design of plate - fin heat exchanger.