基于分层蓄热水箱的相变球释热实验研究

EXPERIMENTAL STUDY ON HEAT RELEASE OF PHASE CHANGE BALL BASED ON STRATIFIED HOT WATER STORAGE TANK

相变蓄热水箱可有效调节集热器和负载端之间供求不匹配的矛盾,设计了环形布水器进水结构和蓄热水箱,并搭建相变蓄热水箱性能测试平台,对比直进型蓄热水箱和环形布水器蓄热水箱的温度分层,探究孔隙率、进水流速和变温进水等变量下相变蓄热水箱的热分层和相变球的释热性能。实验研究表明:环形布水器能有效抑制进水水流对温度场的扰动,保持良好的温度分层,使相变球逐层放热,增大相变球与传热流体(HTF)的温差,提高释热效率,保证高温水能够源源不断地提供给用户端;孔隙率越小分层效果越好;流速越大分层效果越差,但是释热效率有所提高;变温进水比恒温进水,释热时间延长约40%。

The phase change heat storage tank can effectively adjust the contradiction between the supply and demand of the collector and the load end.The water inlet structure and heat storage tank of the annular water distributor are designed,and the performance test platform of the phase change heat storage tank is built.The temperature stratification of the direct type heat storage tank and the heat storage tank of the annular water distributor are compared,and the thermal stratification of the phase change heat storage tank and the heat release performance of the phase change ball under the variables of porosity,water inlet velocity and variable temperature water inlet are explored.The experimental research shows that the annular water distributor can effectively suppress the disturbance of the inlet water flow to the temperature field,maintain good temperature stratification,make the phase change ball release heat layer by layer,increase the temperature difference between the phase change ball and the heat transfer fluid,improve the heat release efficiency,and ensure that the high-temperature water can be continuously provided to the user;The smaller the porosity,the better the delamination effect;The higher the flow velocity is,the worse the stratification effect is,but the heat release efficiency is improved;The heat release time of variable temperature influent is about 40% longer than that of constant temperature influent.