椭圆断面厚壁螺旋管强化传热与流体阻力研究

Study on Heat Transfer Enhancement and Pressure Drop of Spiral Tube with Oval Cross Section and Thick Wall

对椭圆断面厚壁螺旋管进行了强化传热和流体阻力实验研究 .结果表明 ,螺旋管的平均传热系数较光管有大幅度提高 ,最大为原来的 2 2倍 ,其准则方程式为Nu =0 .1 97Re0 .62 5Pr0 .4( 1 0 4 <Re<3.72× 1 0 4 ) .在雷诺数较低时 ,螺旋管的传热效果较好 ,流体阻力也较小 ,随着雷诺数的增大 ,流体阻力迅速增大 .螺旋管强化传热和最佳工作区域在Re<2× 1 0 4 范围内 .

The heat transfer enhancement and pressure drop of spiral tube with oval cross section and thick wall were investigated. The experiment results indicated that the average heat transfer coefficient of the spiral tube increases by a wide margin and its maximum achieves about 2.2 times that of the straight tube. The dimensionless parameters equation of the spiral tube is \%Nu=0.197Re\+\{0.625\}Pr\+\{0.4\}(10\+4<Re<3.72×10\+4\%). The heat transfer effect of the spiral tube is better and the pressure drop is also lower when Reynolds number is smaller.The pressure drop increases rapidly with Reynolds number. It was concluded that the optimum operation range of the heat transfer enhancement spiral tube is between 1×10\+4 and 2×10\+4.