针对太阳能集热管内强化对流换热的突出问题,应用场协同理论,采用铜丝制成多叶螺旋线圈内插元件,对双叶螺旋线圈和三叶螺旋线圈增强流道管壁与工质之间的换热性能进行了实验研究。结果表明:多叶螺旋线圈管道内协同角余弦值cosβ增大,对流换热场协同数Fc较空管有大幅提升,速度场和温度场具有良好的协同性;在以水为工质的定热流工况下(240〈Re〈2300),内置三叶螺旋线圈综合换热效果最好。
To solve the prominent problem of convective heat transfer enhancement in solar collector tubes,experimental investigation on enhancing heat transfer between tube well and medium by copper inserts with double multiple spiral coils and three multiple spiral coils was conducted,by using field synergy theory.The results show that,the convective field synergy number Fc increases sharply with the synergy angle cosine cosβin the multiple spiral coils tubes.Moreover,the velocity field and temperature field also show a good cooperativity.The working fluid with three spiral coils has the best comprehensive heat transfer performance,under the condition with constant heat flow(240〈Re〈2 300)for the experiment with water as the medium.