V型纵槽对水平螺旋管外冷凝传热的强化

用实验方法研究水平螺旋管管外有纵向 V型槽时凝结换热的强化问题。在相同真空度下 ,测试当 V型槽的角度或数目变化时管外凝结换热系数随冷却水流量变化的规律。实验结果表明 ,V型槽夹角为 6 0°,槽深为 1mm,槽数为 2 8时强化效果最佳。还在相同实验条件下 ,比较 V型槽水平螺旋管与矩形槽水平螺旋管及水平螺旋光管的传热效果 ,得到可用于工程实际的 V型槽水平螺旋管外冷凝传热的试验关联式

Research on Enhanced Condensation outside the Horizontal Coil Tube with V Grooves

An experimental investigation is made to study the enhanced condensation heat transfer of horizontal coil tube with longitudinal “V”type grooves.The vacuum is kept unchanged to exclude the influence of air to condensation.The heat transfer coefficients of coil tubes with V grooves of different tangle and number are obtained.Compared with bare coil tube,tube with V grooves has better heat transfer characteristics and the results show the best construction is grooves with depth h=1mm,number N =28 and tangle φ =60°.Criterion equation is also obtained to describe the condensation heat transfer outside coil tube with V grooves.