【摘要】 热管堆具有结构简单、布局紧凑、固有安全性高的特点，是无人潜航器的理想堆型之一。针对采用热管堆的新型兆瓦级高效紧凑核动力装置，设计了一种利用自然循环冷却热管绝热段的非能动余热排出系统。使用计算流体力学方法对不同几何参数的余排系统的排热能力进行模拟分析，使其保守满足最大余排功率的需求。结果表明：热管管束周围设计围板导流有利于降低流体最高温度，围板进出口宽度几乎不影响换热能力，而延长围板下部不利于自然循环；3.5兆瓦热管堆的应急冷却舱轴向长度为160 mm时可以保守满足最大余排功率，并在5～25℃的环境温度下均可正常工作。更多还原

【Abstract】 [Background] A heat pipe reactor is ideal for underwater unmanned vehicles(UUV) because it is simple, is compact, and has high inherent safety. [Purpose] A passive residual heat removal system that uses natural circulation to cool the adiabatic section of heat pipes was designed based on the characteristics of a new type of megawatt compact nuclear power plant with a heat pipe reactor. [Methods] Firstly, based on the characteristics of 3.5megawatt compact nuclear power plant for UUV, natural circulation of water was utilized to cool the adiabatic section of heat pipes. Then, the computational fluid dynamics software STAR-CCM+ was used to simulate and analyze the heat removal capacity of the passive residual heat removal system with different geometric parameters, made it conservatively meeting the demand of maximum residual heat removal power. [Results & Conclusions] The results show that a baffle around the adiabatic section of heat pipe bundle is beneficial to reduce the maximum temperature of the fluid. The widths of the inlet and outlet of the baffle have almost no effect on the heat removal capacity, while extending the lower part of the baffle is unfavorable to natural circulation. When the axial length of the emergency cooling chamber is 160 mm, it can conservatively meet the maximum residual heat power of 0.14 MW. The maximum fluid temperature is 288 ℃, which is lower than the boiling point under working pressure, and normal operation is possible in ambient temperatures ranging from 5 ℃ to 25 ℃.更多还原