脉动热管启动过程的实验研究

为了使电子设备在启动过程中具有更好的稳定性,采用控制恒定热流密度和冷凝温度的方法对平板开槽型脉动热管的启动过程进行了系统的实验研究．实验发现:在特定工况下,启动过程中脉动热管管内工质会突然剧烈沸腾,此时脉动热管蒸发段温度突然降低,冷凝段温度突然升高,广义热阻突然降低．针对本实验装置,存在一个使脉动热管启动迅速而且达到稳定运行状态时广义热阻最小的最佳充灌率(50%)、最佳管体倾斜角度(50°)和最佳加热功率(28．5 W)．热管冷却段冷却水流量对脉动热管启动性能影响较小．

Experimental Study on Start-up Process of Pulsating Heat Pipe

An experimental investigation for a looped and parallel-grooved pulsating heat pipe (PHP)was carried out to obtain a more steady start-up process for an electrical apparatus with controlling the input heat flux and condensing temperature.The experimental results show that the working fluid in the pipe abruptly boils in a special condition at the start-up process,and meanwhile the temperature in the evaporating section of PHP falls and the temperature in the condensing section increases.The broad sense thermal resistance of PHP suddenly falls down at the same time.Moreover,the PHP quickly attains steady working state with an optimum charge rate of 50 per cent of volume quantity,an optimum inclination angle of 50 degrees and an opti- mum heating capacity of 28.5 W.In addition,the effect of the cooling water flux on the perform- ance of the PHP's start-up process is weak.