三维内肋螺旋管内强化换热实验

采用实验方法测试了三维内肋螺旋管内的流动传热性能。实验用的螺旋管曲率δ=0．0663，测试段长1．15m，试验工质为水。对螺旋光管和两种不同结构尺寸的三维内肋管进行了测试，测量的雷诺数范围约为Re=1000～8500。结果表明，三维内肋对螺旋管内的对流换热仍然有较大的强化效果，同时流阻也有一定程度的增加。与未加肋的螺旋光管相比，在测试的流动范围内，两种三维内肋管的平均换热强化比达1．71和2．03．热力性能系数为1．2～1．66。

Experimental Research on Intensified Heat Exchange in a Three-dimensional Internally Finned Helical Pipe

Tests and measurements were performed to investigate the flow and heat transfer performance in a three-dimensional internally finned helical pipe with a curvature of 0.066 3 and measurement section length of 1.15 m. With water serving as a working medium tests were carried out in a spiral bare pipe and a three-dimensional internally finned pipe of two different structural dimensions. The range of Reynolds number is Re = 1 000-8 500. The test results indicate that a relatively high intensification of convection heat exchange can be achieved in the spiral pipe by the use of three-dimensional inner fins, which is accompanied by a moderate increase in flow resistance. In comparison with bare spiral pipes without fins the average intensification ratio of heat exchange for the two kinds of three-dimensional internally finned pipe within the range of measured flows can reach 1.71 and 2.03 respectively with the thermodynamic performance factor being assessed at 1.2 - 1.66.