L齿型螺旋肋片管表面放热系数沿其周向的变化规律的研究

本文介绍L齿型螺旋肋片管表面放热系数沿试验管周向的变化规律。作者采用试验与数值计算相结合的方法。试验中仅在肋片管肋肩的一个角度埋设热电偶,在保持试验工况不变的情况下旋转试验管,从而测得不同角度上的肋肩温度。然后列出二维有限差分方程,通过计算求得该种肋片管表面放热系数在不同R_c下沿周向的变化规律。

Research on Variation of Surface Heat Transfer Coefficients Around the Circle of a helically welded L-Type Segmented Finned Tube

In order to obtain the law on the variation of surface heat transfer coefficient around the circle of helically L-type segmented finned tube, the authors present a new method in which experiments are combined with numerical solutions. In the experiment, thermocouples are only set on one angle, and the temperatures at different angles are measured by rotating the tube tested under the same experimental condition. Then the local average surface heat transfer coefficients at different angles of the tube can be obtained by solving the two-dimensional finite difference equation group which is derived in terms of the first and third type boundary conditions on the outside surface of the tube. Finally, the data are presented and an analysis is made.