实验研究和分析了一种新型下冷式脉动热管太阳能集热器的传热特性。与传统太阳能集热器相比，下冷式脉动热管太阳能集热器水箱位于底部，真空玻璃管不盛水并嵌于水箱上，脉动热管作为传热元件，一部分置于真空玻璃管内，另一部分封于水箱中。实验过程中通过调整脉动热管冷热段间的比例，研究不同情况下集热器启动、运行特性及传热性能。结果表明，在集热器倾角为70°、脉动热管充液率为55%的情况下，脉动热管的当量导热系数随冷热段比例的减小而先升后降；当冷热段比例为47%时，脉动热管的启动温度最低、传热性能最优。

To investigate the heat transfer characteristics of a new type of bottomcooling PHP of solar collector,a new system was designed and experiment was carried out.Compared with the traditional solar collector,the bottomcooling PHP of solar collector water tank is located at the bottom,in which the vacuum glass tube is embedded without water.The experimental method is as follows: The PHP is used as a heat transfer element,a part of it is arranged in vacuum glass tube,while the other is placed in the water tank.During the experiment,by adjusting the ratio between the cold and hot sections of the PHP,the startup,operation characteristics and heat transfer performance of the collector under different conditions were studied.The results indicate that under the condition that the inclination of the collector is 70° and the filling rate of the PHP is 55%,the equivalent thermal conductivity of the PHP increases first and then decreases with the decrease of the proportion of the cold and hot sections.The PHP has the lowest startup temperature and best heat transfer characteristics when the ratio between lengths of the cold and hot sections of the PHP is 47%.

TK513.5

吉林省科技攻关项目（20190303113SF）；吉林省产业技术研究与开发项目（2019C057-5）