不凝气对池内亚音速蒸汽直接接触凝结影响

Effects of non-condensable gas on subsonic steam direct contact condensation in a pool

利用VOF多相流模型和修正的热相变凝结模型对含不凝气蒸汽亚音速射入池内的直接接触凝结过程进行了数值模拟。主要研究了不同不凝气含量对蒸汽直接接触凝结过程中气羽形态、温度和压力分布的影响。研究结果表明:随着凝结的进行不凝气在气液界面处集聚成为一层不凝气层,随着不凝气含量的增加,不凝气层的厚度也增加,气羽不再呈现周期性的变化;不凝气的存在使得池内温度高温区域增大,温度分布相对均一;同时随着不凝气含量的升高,压力振荡的强度减弱,凝结形成的负压值升高。

The subsonic steam direct contact condensation in a pool with non-condensable gas was numerically simulated using the VOF multiphase flow model and the modified thermal phase change condensation model.The effects of non-condensable gas mass fraction on the gas plume,temperature and pressure distribution during the direct contact condensation were studied.The numerical results show that the non-condensable gas accumulates at the gas-liquid interface and forms a non-condensable gas layer.As the non-condensable gas mass frication increases,the thickness of the non-condensable gas layer also increases and the gas plume no longer exhibits cycles.The presence of non-condensable gas increases the high temperature zone in the pool and the temperature distribution is relatively uniform.At the same time,with the concentration of non-condensable gas increases,the intensity of pressure oscillation decreases and the negative pressure value increases.