Optimization design of cesium heat pipe based on orthogonal test

Medium-temperature heat pipes have potential applications in the fields of secondary heat exchange in nuclear reactors, medium-temperature constant temperature control and thermal protection of aircraft, etc. It is of great significance to carry out the study of precious metal heat pipes using numerical simulation and optimize their full-parameter design. First, a porous reflux model was added to the adaptive phase change model by UDF, and the accuracy of the model was verified by comparing the experimental data and the conclusion of the base model. Secondly, the orthogonal test method was introduced to study the order of importance of the influence of each factor on the performance of the heat pipe under the interaction of all factors, and the result proved that the order of significance of the influence of the factors within the range of the selected working conditions was inclination angle>aspect ratio>liquid filling ratio>mesh number, and the optimal design conditions were 17.18 aspect ratio, 15% liquid filling ratio, inclination angle δ=45°, and 50-mesh screens. And under this condition, the overall thermal resistance was only 15.6% of the worse working conditions, and the heat transfer performance was significantly enhanced. Finally, by comparing and analyzing the phase distribution, temperature distribution and dry burning phenomenon inside the heat pipe and porous structure from the beginning of the complete startup to the quasi-steady state process, it was proved that the distribution of condensate inside the porous structure of the heat pipe wall under the optimal design parameters could be maintained uniformly and continuously, which effectively avoided local overheating of the wall and significantly improved the temperature uniformity of the heat pipe. At the same time, the matching of the parameters such as length-to-diameter ratio and liquid filling rate made the effective heat transfer length of heat pipe up to 100%. © 2024 Chemical Industry Press Co., Ltd.. All rights reserved.