空间反应堆系统液体层辐射换热特性分析

Analysis of Radiation Heat Transfer Characteristics of Liquid Sheet Radiator in Space Reactor System

为研究空间反应堆系统液体层辐射换热器的换热特性,本文运用STAR-CCM+软件进行了几何、物理建模,通过改变几何尺寸、形状、发射端温度及工质种类,对不同形式液体层的辐射换热特性进行数值计算和分析,得到了上述各因素的影响规律和作用机理。结果表明:改变矩形液体层模型的形状使比传热面积增加,可改善液体层的辐射换热性能;矩形和三角形液体层形状变化的灵活度较高,能达到更优的辐射换热性能;提高液体层的发射端温度可减小液体层质量,大幅改善液体层辐射换热性能,但需考虑升温带来的工质蒸发速率加快的影响;密度小而发射率大的工质性能更优,综合考虑蒸发和造价因素,高温下液态锡更适合作为辐射换热器的工质。研究结果为空间液体层辐射换热器的优化设计提供了一定的理论支撑和科学依据。

To investigate the radiation heat transfer characteristics of liquid sheet radiator in space reactor system,the geometric and physical model was established with STAR-CCM+.By changing the geometry size,shape,transmitting temperature,and working fluid of the liquid sheet,the numerical calculation was conducted and radiation heat transfer characteristic was analyzed.It can be concluded that in the rectangular liquid sheet,the heat rejection power per unit mass increases with the radiation area per unit mass.For the shape,liquid sheet can achieve better radiation heat transfer performance,as rectangle and triangle with same area have more room to change shape.The radiation heat transfer performance can be improved and the mass of liquid sheet radiator can be reduced by increasing the transmitting temperature.However,high temperature also accelerates evaporation of the working fluid.The working fluids with small density and high emissivity have better performance.Considering the factors of evaporation and economics,liquid tin is a better choice as working fluid at high temperature.The research result provides theoretical support and scientific basis for the optimization design of space liquid sheet radiator.