高温钾热管稳态运行传热特性研究

Study on Heat Transfer Performance of High Temperature Potassium Heat Pipe at Steady State

本文采用钾金属作为热管工质,对热管的传热性能展开理论和实验研究。首先,对不同加热功率和倾角下热管传热性能影响规律进行实验研究。结果表明,热管加热功率的提升有利于传热性能的改善,加热功率升高导致蒸发加剧,蒸气密度增加,进而强化蒸气传热。倾角对传热性能有正反两方面的作用。一方面,随倾角的增加冷凝段液膜不稳定性加剧,导致传热恶化;另一方面,倾角的增加导致重力加速液体工质回流并减薄冷凝段液膜,传热增强。在二者的共同作用下,随倾角的增加,热管等效热阻逐步增加且超过某一限值后趋于平稳。其次,以热阻网络法为指导,建立了钾热管的数学物理模型,并基于模块化程序思想,开发了热管设计分析程序。通过与实验数据对比,二者整体误差在2.7%以内,验证了热管模型的合理性。本文对碱金属高温热管的设计优化提供了数据及理论支持。

The heat transfer performance of heat pipe was studied theoretically and experimentally by using potassium metal as working medium in this paper.Firstly,the influence of heating power and inclination angle on heat transfer performance of heat pipe was studied experimentally.The results show that the increase of heating power of heat pipe is beneficial to the improvement of heat transfer efficiency.The inclination angle has positive and negative effects on heat transfer performance.On the one hand,with the increase of inclination angle,the instability of liquid film in condenser section leads to the deterioration of heat transfer.On the other hand,the increase of inclination angle causes gravity to accelerate the reflux of liquid working medium and thin the liquid film in condenser section,enhancing the heat transfer.Under the joint action of the two,with the increase of inclination angle,the equivalent thermal resistance of the heat pipe gradually increases and tends to be stable.Secondly,based on the network method of thermal resistance,the mathematical and physical model of potassium heat pipe was established,and the design and analysis program of heat pipe was developed based on the idea of modular program.Compared with the experimental data,the overall error of the two is within 2.7%,which verifies the rationality of the model.In a word,this paper provides data and theory for the design and optimization of alkali metal high temperature heat pipe.