【摘要】 针对前苏联研制的TOPAZ-Ⅱ空间热离子反应堆,结合成熟的高温热管技术,对改进型热辐射换热器传热单元进行瞬态特性研究。采用有限元方法对热管瞬态启动特性进行数值模拟。翅片温度计算采用有限差分进行求解,并与热管壁面进行单向耦合传热。热管启动过程中采用Cotter热管极限理论,即重力极限、声速极限、携带极限来判定热管启动状态。研究结果表明:热管390s内启动迅速,在启动第2阶段遇到声速极限,从而限制了热管启动时间。热管和翅片最终达到稳态,温度分布均匀,当量换热系数为1 783.25 W/m~2。热管换热单元能有效地将热量导入到外界。更多还原

【Abstract】 Based on the high temperature heat pipe technology,the transient heat transfer behavior of unit cell on improved thermal-radiator of TOPAZ-Ⅱ proposed by former USSR was analyzed.Different numerical methods,such as finite element method(FEM)for heat pipe wall and wick region and finite difference method(FDM)for heat pipe fin,were employed to simulate the startup process of the heat transfer unit.The strong coupled heat and mass transfer among each heat pipe region was considered based on one-way coupling strategy.In addition,the sonic limit,capillary limit and entrainment limit from Cotter’s heat pipe limits theory were set as the evaluation criteria ofheat pipe successful operation.Numerical results show that heat pipe starts up rapidly within 390 sand encounters the sonic limit during stage 2.The steady state of heat transfer unit is finally reached with high isothermality,and the equivalent heat transfer coefficient is 1 783.25 W/m~2.Overall,the heat transfer unit has a good heat removal performance.更多还原