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

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