摇摆条件下船用蒸汽蓄热器放汽过程数值研究

Numerical Investigation on Discharging Process of Marine Steam Accumulator under Rolling Motion Condition

基于两流体模型和热相变模型,结合考虑附加惯性力的摇摆计算模型,并且引入指数压降放汽边界条件,利用CFX软件进行了摇摆条件下船用蒸汽蓄热器放汽过程数值计算。计算结果显示,在摇摆条件下,蒸汽蓄热器放汽压力和温度均快速降低,但摇摆运动对放汽压力和温度参数影响比较小;摇摆运动加强蒸汽蓄热器内汽水两相流体的湍流交混,诱发蓄热器压力场、速度场和温度场分布紊乱;周期性的摇摆运动导致蒸汽蓄热器水位产生剧烈的周期性波动,且波动周期与摇摆周期基本一致。摇摆模型在蒸汽蓄热器两相流数值模拟中的成功应用,可以为海洋条件下蒸汽蓄热器热工水力的准确分析提供参考。

Based on the two-fluid model, the thermal change model and rolling model with consideration of the additional intertia force, using the exponential pressure drop boundary conditions, a numerical calculation about discharging process of a marine steam accumulator at rolling motion is carried out with CFX code. The calculated results show that both discharging pressure and temperature reduce fast under the rolling motion condition. However, the discharging parameters for pressure and temperature are less affected by the rolling motion. The rolling motion can strengthen turbulent mixing for steam and water two phases flow, which induces the chaotic distributions of pressure, the velocity and the temperature field. The periodic rolling motion can lead to tempestuously periodic fluctuation. Meanwhile, the fluctuation period is consistent with the rolling period. The successful application of the rolling model to two-phase flow numerical simulation of a steam accumulator can supply reference for thermal-hydraulic accurate analysis of a steam accumulator under the sea condition.