【摘要】 对不同结构的螺旋扁管管内传热及流体阻力性能进行实验研究,并与光管比较,选出传热与流阻综合性能较好的管型。同时对2台螺旋扁管换热器及1台外螺纹螺旋扁管换热器进行壳程传热与流阻实验研究。根据实验结果给出了管、壳程传热膜系数与阻力系数的经验关联式。更多还原

【Abstract】 Twisted tubes with different structural parameters (Froude number) were investigated at 1000<Re<17000. The tube side heat transfer and flow friction properties were compared with those of smooth tube. The tube with the hightest(Nui/Nus)/(λ/λ3)1/3 value was choosen from the five tubes. Two twisted tube heat exchangers and one twisted fin - tube heat exchanger were used to study shell -side heat transfer and flow resistance properties at 1000<Re<10000. The result shows that twisted tube bundle enhances heat transfer of both tube -side and shell -side. It is found that twisted fin -tube heat exchanger has a high heat transfer coefficient and a low flow resistance factor compared with the same type of twisted tube heat exchanger. The correlation equations of heat transfer coefficient and flow friction factor of both inside and outside tubes are given respectively.更多还原