脉动热管太阳能集热器传热性能实验研究

Experimental study on heat transfer performance of pulsating heat pipe solar energy collectors

以真空玻璃管为载体、石蜡为相变储热材料、脉动热管和铜管为传热元件,对比分析了充液率φ=50.0%的脉动热管太阳能集热器与铜管太阳能集热器在相同辐照度下的集热性能。研究结果表明,当辐照度大于0 W/m^(2)时,脉动热管太阳能集热器相比于铜管太阳能集热器管壁温度提高了40℃;相较于铜管太阳能集热器,热源温度越高,脉动热管太阳能集热器吸热能力越强,传热效果越好;在相同的辐照度下,相比于铜管太阳能集热器,脉动热管太阳能集热器内的石蜡达到熔点的时间缩短了13%;脉动热管太阳能集热器输出的热量比铜管太阳能集热器高0.5 kJ,随着辐照度的增强,热量差值将会更大;脉动热管蒸发段和冷凝段壁面与其相接触的传热工质会形成一种准平衡态,蒸发段与冷凝段的传热能力呈反比关系,当蒸发段传热能力下降时,冷凝段传热能力上升,保证了集热器的稳定运行。

Using vacuum glass tubes as the carrier,paraffin wax as the phase change heat storage material,pulsating heat pipe and copper pipe as the heat transfer elements,the heat collection performance of pulsating heat pipe solar energy collectors and copper pipe solar energy collectors with liquid filling ratioφ=50.0%at the same irradiance is compared and analysed.The results show that when the irradiance is greater than 0 W/m^(2),the wall temperature of pulsating heat pipe solar energy collectors is 40℃higher than that of copper pipe solar energy collectors.Compared with copper pipe solar energy collectors,the higher the heat source temperature is,the stronger the heat absorption capacity of pulsating heat pipe solar energy collectors is,and the better the heat transfer effect is.Under the same irradiance,the time for paraffin wax to reach the melting point in pulsating heat pipe solar energy collectors is 13%shorter than that in copper pipe solar energy collectors.The heat output of pulsating heat pipe solar energy collectors is 0.5 kJ higher than that of copper pipe solar energy collectors,and the heat difference will be larger with the increase of irradiance.The heat transfer working fluid in contact with the wall of the evaporation section and condensation section in the pulsating heat pipe will form a quasi-equilibrium state,and the heat transfer capacity of the evaporation section is inversely proportional to that of the condensation section.When the heat transfer capacity of the evaporation section decreases,the heat transfer capacity of the condensation section will increase,which ensures the stable operation of the collectors.