Abstract: Thermal performance of high temperature heat pipe with triangular grooved wick under variable heat fluxes has been investigated experimentally, and temperature, thermal resistance and response time have been analyzed by considering the periods and amplitudes of cyclical input power and inclination angles of heat pipe. The results show that: at start-up stage, in this experiment there is no evident difference in stable temperature and time under constant and variable power heating with the same average power. There are greater temperature fluctuations of the heat pipe with longer period or larger amplitude of the variable power. Triangular grooved heat pipe runs stably at variable heat fluxes, and can withstand harsh working conditions of 3000 W (760-3800 W) power changing in 6 min. This heat pipe has better temperature uniformity with 0° than with 45° inclination angle under variable heat fluxes. High temperature heat pipe with triangular grooved wick has good thermal response and thermal buffer under variable heat conditions, so it can further improve the system reliability.

Key words: solar energy, heat transfer, measurement, high temperature heat pipe, triangular groove, variable heat fluxes, period, amplitude

摘要： 针对高温热管在交变功率下的传热性能进行了试验研究，考虑功率的变化周期、振幅和热管的倾角等因素，分析了热管的温度、热阻及其热响应时间的变化。结果表明：在本实验条件下，恒定加热功率启动的时间与温度，和平均功率与之相等的周期交变功率启动时基本相等。交变功率的周期越长、功率振幅越大，温度波动越大，对热管的影响越大。三角沟槽高温热管在交变热通量下运行良好，性能稳定，能承受6 min内功率变化3000 W（760～3800 W）的恶劣工况。三角沟槽热管在交变功率下水平运行较45°倾角时均温性更好。高温热管具有较好的热响应和热缓冲作用，可显著提高所在系统的可靠性。

关键词: 太阳能, 传热, 测量, 高温热管, 三角沟槽, 变热流, 周期, 振幅