基于气液两相流入口蒸汽参数对管壳式冷凝器性能的影响

The Effect to the Performance of Shell-and-tube Condenser of Inlet Steam Parameters Based on Gas-liquid Two-phase Flow

采用数值模拟方法,使用CFD软件FLUENT对管壳式冷凝器壳侧按两相流动及相变传热进行了模拟计算,选定合适的湍流模型、两相流模型为混合物模型,并根据汽水转化公式编写了自定义函数UDF来描述相变过程质和量的传递。针对壳侧流体介质为高温饱和水蒸汽情况下,分别对不同的介质入口速度和入口温度情况下换热器壳侧传热系数、湍流动能和压强变化的模拟结果进行了比较,得出了流体介质入口速度与温度对换热器壳侧传热特点和传热性能的影响规律。从而对冷凝器壳侧结构参数的优化及流动介质进行合理的选择起到指导作用。

Numerical-simulation methods are adopted here. With the help of CFD and FLUENT soft- ware, the two-phase flow and phase change and heat transfer is simulated.A turbulence model and a two- phase flow model are selected. Based on the characteristics of shell-side in the shell-and-tube condenser, User-defined Function （UDF）is introduced to describe the phase transition of quality and quantity through the use of the conversion formula, analyzing the influence on the condenser coeffwients and its pressure. Choosing saturated vapor as the liquid medium at the inlet of shell-side of the shell-and-tube heat ex- changers,it focuses on comparing the simulation results on the heat coefficient,turbulent momentum and pressure distribution of the shell-and-tube heat exchangers at the inlet.The experimental results reveal the influence law of the velocity and temperature of fluid medium inlet to the characteristics and the perfor- mance of the heat exchanger shell side.These provide some valuable references to the improvement of tube condenser structure parameter optimization, and the choice of flow media.