相变式U形管太阳能集热器的性能

通过结合太阳能集热器与相变材料（石蜡）搭建相变式U形管太阳能集热器性能测试平台，探究和对比与普通的U形管太阳能集热器在产水量和集热性能的表现。实验结果表明：石蜡的应用可以使U形管集热器的产水量增加462g，持续时间延长0.5h。在测定的工况条件下，相变式U形管太阳能集热器集热效率在夏季和过渡季节分别可以达到54.6%和28.51%。此外，随着工作介质流量的提高，夏季的有用热的提高率从38.26%降至14.66%，过渡季节有用热的提高率从38.67%降至13.85%。在实际应用中应考虑工作流量对相变式U形管集热器的影响。

Performance of U-tube solar collector with phase change materials

This study combined U-tube solar collector and phase change materials (paraffin wax) to fabricate an experimental platform for comparative investigation on water production and heat storage performance. The experimental results represent that the application of paraffin wax could effectively increase water production by 462g and working duration by 0.5h. At given test conditions, the thermal efficiency of U-tube solar collectors integrated with paraffin wax could reach approximately 54.6% and 28.51% in summer and transition season, respectively. In addition, the enhancement ratio of useful heat decreases from 38.26% to 14.66% in summer and 38.67% to 13.85% in transition season with an increase in the flow rate of the working medium. The findings suggest that the flow rate should be considered to optimize the application of U-tube solar collector integrated with paraffin wax in a practical project.