基于欧拉壁面液膜模型的管内蒸汽冷凝流动和液膜特性的数值模拟研究

Numerical Simulation of Steam Condensation Flow and Liquid Film Characteristics in Tubes Based on Euler Wall Liquid Film Model

采用ANSYS FLUENT软件建立了基于欧拉壁面液膜模型的光滑管内蒸汽冷凝流动过程的三维数学模型。模拟管长为500 mm,内径为38 mm。模拟工况为入口蒸汽饱和温度分别为70℃,总传热温差为5℃和7℃,入口蒸汽速度为1420 m/s。模拟结果表明,液膜厚度在管道底部随着流动距离的增加而增加,液膜厚度在管顶部先增大后趋于稳定,更大的蒸汽入口速度产生更高的液膜厚度。液膜流动速度在管道底部随着流动距离的增加而增加,液膜流动速度在管顶部先增大后缓慢降低,更大的蒸汽入口速度产生更高的液膜流动速度。

A three-dimensional mathematical model of steam condensation flow in a smooth tube based on Euler’s liquid film model was established by using ANSYS FLUENT software.The simu-lated pipe is 500 mm in length and 38 mm in diameter.Under simulated conditions,the saturation temperature of inlet steam is 70℃,the total heat transfer temperature difference is 5◦C and 7℃,and the inlet steam speed is 14∼20 m/s.The simulation results show that the liquid film thickness increases with the increase of the flow distance at the bottom of the pipe,and the liquid film thick-ness increases first and then becomes stable at the top of the pipe.The larger steam inlet velocity produces higher liquid film thickness.The liquid film flow velocity increases with the increase of the flow distance at the bottom of the pipe,and the liquid film flow velocity increases first and then slowly decreases at the top of the pipe.A larger steam inlet velocity produces a higher liquid film flow velocity.