余热排出系统中的热管设计及传热性能研究

Heat Pipe Design and Heat Transfer Performance in Residual Heat Removal System

本文建立了单根热管的优化设计流程及其传热传质数学物理模型,考虑热管的工作环境,对用于核反应堆非能动余热排出系统中热管换热器的热管进行了完整的优化设计和传热特性分析。分析表明:复合型吸液芯热管满足余热排出系统的传热需求,其传热功率主要受热管毛细极限、沸腾极限及总热阻的影响。相同吸液芯厚度下,复合型吸液芯热管的毛细极限较单一丝网吸液芯热管的毛细极限提高100%~700%。改变热管的外径或吸液芯厚度,即蒸气腔直径减小,沸腾极限明显减小。当单根热管传热功率大于1 kW时,热管各段长度分别为0.4、0.2、0.4 m,外径为30 mm,吸液芯是厚度为2 mm的400目+50目复合型丝网结构。本文为高性能的热管换热器设计及传热特性分析提供了理论支撑。

In this paper,the optimal design process of a single heat pipe and its heat and mass transfer mathematical and physical model were established.Considering the working environment of the heat pipe,the heat pipe used for heat exchanger in the passive residual heat removal system of the nuclear reactor was completely designed,and its heat transfer characteristics were analyzed.The analysis shows that the composite wick heat pipe meets the heat transfer requirements of the residual heat removal system,and its heat transfer power is mainly affected by the capillary limit,boiling limit and total thermal resistance of the heat pipe.With the same wick thickness,the capillary limit of the composite wick heat pipe is 100%to 700%higher than that of the single wire mesh wick heat pipe.Changing the outer diameter of the heat pipe or thickness of the wick,that is,reducing the diameter of the steam cavity,the boiling limit significantly reduces.When the heat transfer power of a single heat pipe is greater than 1 kW,the length of each section of the heat pipe is 0.4,0.2 and 0.4 m,the outer diameter is 30 mm, and the wick with a thickness of 2 mm is a composite wire structure of 400 mesh+ 50 mesh.This paper provides theoretical support for the design of high performance heat pipe heat exchangers and the analysis of heat transfer characteristics.