Session: 11-01: Micro/Miniature Two-Phase Devices/ Systems

Paper Number: 132016

132016 - Experimental Study on the Heat Transfer Performance of a Cesium Oscillating Heat Pipe 

Abstract: 

The liquid metal high-temperature oscillating heat pipe ( LMHOHP ) is a highly efficient heat transfer device capable of operating in extremely high-temperature environments exceeding 500℃. Given its potential, the oscillating heat pipe is expected to play an integral role in the field of high-temperature thermal dredging. Due to the active chemical properties, explosive risk and high price of cesium metal, research on liquid metal LMHOHP with cesium as a working fluid has not been reported. However, research on LMHOHPs with sodium, potassium and sodium-potassium alloys as working fluids is dominant. In view of the application of LMHOHPs and the need for systematic academic research, a liquid metal high-temperature heat pipe with cesium as the working fluid was fabricated in this paper and the filling rate was 50 %. The oscillating heat pipe used a 310s stainless steel capillary tube with an inner diameter of 4 mm and an outer diameter of 6 mm to bend into a serpentine array, and the number of turns was 6. In the experiment, a heating furnace was used to heat the evaporation section of the LMHOHP. Operating temperatures of 80 °C and various inclinations angles of 90 °, 60 °, 30 °, and 0 ° were studied to analyze their impact on the start-up performance and heat transfer performance. The experimental results demonstrated that the start-up evolution process of cesium LMHOHP was similar to that of sodium-potassium alloy LMHOHP. For the inclination angles of 90 °, 60 °, and 30 °, and heating powers ranging from 1500W to 3250W, the cesium working fluid exhibited oscillating heat transfer characteristics and no unidirectional circulating flow was observed. By increasing the heating power, the oscillation frequency of the working fluid accelerated, enhancing the heat transfer performance. The heating furnace mainly utilizes radiation heat transfer to heat the evaporation section of the cesium LMHOHP. When the inclination angle was 0°, the maximum heat transfer power was 464 W, the thermal resistance was 2.15 K/W, and the heat transfer performance was relatively bad. As the working inclination angle increased, the maximum heat transfer power also increased, the temperature difference between the condensation and evaporation section and the thermal resistance gradually decreased, the heat transfer performance also improved. In the experiment, the optimal heat transfer performance of the cesium LMHOHP was observed when the inclination angle was  90° and the heating power was 3250W. The minimum thermal resistance achieved during the experiment was 0.18K/W, while the maximum equivalent thermal conductivity was 5560W/m·K.

Presenting Author: Yanmin Feng Dalian Maritime University

Presenting Author Biography: Yanmin Feng, a male PhD candidate, primarily focuses on the theory and application of oscillating heat pipes and efficient heat transfer research.

Authors:

Yanmin Feng Dalian Maritime University
Yulong Ji Dalian Maritime University
Zhonghao Liu Dalian Maritime University
Mengke Wu Dalian Maritime University
Huaqiang Liu Dalian Maritime University