螺旋管内单相及沸腾的强化换热与阻力特性实验

实验研究了三维内肋螺旋管内单相及沸腾的强化换热与阻力性能。单相对流换热实验采用光滑螺旋管和两种不同结构尺寸的三维内肋螺旋管。与光滑螺旋管相比，在测试的流动范围内．两种三维内肋管的平均换热系数增加了71％和103％．平均阻力增加了90％和140％；曲率δ=0．0605、测试段长0．58m的三维内微肋螺旋管内流动沸腾换热实验结果表明：在不同质量流速、热流密度工况下，三维内微肋螺旋管的平均换热系数比光滑螺旋管增加40％到120％．阻力增加18％到119％。

Experiments on Heat Transfer Enhancement in 3D Inner Finned Helical Pipe

Experiments were performed to investigate the enhancement performance of single-phase flow and boiling heat transfer in the 3D inner finned helical pipes. The experimental results of two finned helical pipes with different inner fin geometry showed that the heat transfer and flow resistance in the 3D inner finned helical pipe gained greater augmentation than those in the smooth one. Within the measured range of Reynolds number, the average augmentation ratio of heat transfer for the two finned pipes are 71% and 103%, respec- tively, compared with the smooth helical pipe, and flow resistance are 90% and 140%. The tests for boiling heat transfer were carried out in the 3D inner finned helical pipes with the curvature of 0.0605 and the length of 0.668m.Comparied with that in the smooth helical pipe, the boiling heat transfer coefficient in the 3D finned helical pipe had been increased by 40% to 120% under various mass flow rates and wall heat flux, and the flow resistance coefficient increased by 18% to 119%.