重力铯热管等温性能研究

Study on Isothermal Characteristics of Gravity Cesium Heat Pipe

为了验证铯热管研制的关键技术,通过测量热管外壁温度,在定温条件下研究了重力铯热管的等温特性和启动性能;同时,分析了冷凝段长度对铯热管等温性能的影响。实验结果表明:当加热炉温度在330~630℃,铯热管均能正常启动;加热炉温度越高,启动越快;在该温区,铯热管具有优良的传热性能;然而,当冷凝段长度为300 mm时,铯热管壁面温度出现锯齿状周期波动。从过热度的角度,分析了铯热管内部的沸腾相变传热机理;选择合适长度的冷凝段可避免周期性间歇沸腾的产生。实验结果同时也了证明铯热管在330~630℃温区可作为高效的传热元件,非常适合复现ITS-90国际温标锌凝固点。

To verify the key technology of the development of the cesium heat pipe,the isothermal performance and the start-up characteristics of the gravity cesium heat pipe were studied under a constant temperature condition by measuring the temperature distribution of the outer wall of the heat pipe.Also,the effects of the length of the condensation section on the isothermal performance of the heat pipe were analyzed.The results showed that,the cesium heat pipe can start normally when the temperature of the heating furnace was in the range from 330℃ to 630℃ and had a good heat transfer ability.Moreover,the higher the temperature of the heating furnace,the faster the start-up of the heat pipe.The temperature of the wall surfaces of the heat pipe showed serrated temperature fluctuations when the length of the condensation section is 300 mm.The mechanism of boiling phase transition heat transfer was analyzed in the heat pipe from the perspective of superheat.The selection of a suitable length of condensation section can avoid the occurrence of the phenomena of the periodic intermittent boiling.In addition,the experimental results proved that the cesium heat pipe can be used as a high-efficiency heat transfer element within the temperature range from 330℃ to 630℃,and is suitable for realizing the zinc freezing point of the ITS-90.