钠热管传热极限过渡数值模拟分析

Numerical Simulation Analysis of Heat Transfer Limit Transition in Sodium Heat Pipe

钠热管在空间核电源领域具有广泛应用。文章以2 m长钠热管为研究对象,通过引入动量源项描述毛细力,模拟钠热管遭遇不同传热极限过渡时管内的相变流动过程。钠热管在主要工作温度范围内,主要受到黏性极限、声速极限、夹带极限和毛细极限的影响,因此存在3个过渡点。模拟分析结果表明:黏性极限与声速极限过渡时,热管蒸发段未出现液体团聚和蒸气阻塞现象;声速极限与夹带极限共同作用时,既出现了蒸气阻塞和液体夹带现象,又伴随着新的液体堆积现象;夹带极限与毛细极限共同作用时的现象与各自单独发生时的现象都有所区别。文章研究结果可用于深入理解钠热管工作机理和优化设计,为更加高效的空间核电源系统设计提供科学参考。

Sodium heat pipes have a wide range of applications in the field of space nuclear power sources.A 2m long sodium heat pipe is taken as the research object in this paper,and the capillary force is described by introducing the momentum source term,and the phase change flow process in the sodium heat pipe is simulated when it encounters different heat transfer limit transitions.Sodium heat pipes are mainly affected by the viscosity limit,the sonic limit,the entrainment limit and the capillary limit within the main operating temperature range,therefore there are three transition points.The simulation analysis results show that there is no liquid agglomeration or vapor blockage in the evaporator section of the heat pipe during the transition between viscosity limit and the sonic limit.The vapor blockage and liquid entrainment phenomenon can occur as the sonic and entrainment limits are combined,along with the liquid accumulation.And when the entrainment limit and capillary limit act together,the phenomenon is different from that when they appear separately.The research results of this paper can be used to gain a deeper understanding of the working mechanism and optimization design of sodium heat pipes,providing a scientific reference for the more efficient design of space nuclear power systems.