齿型螺旋肋片管表面局部放热系数

对齿型螺旋肋片管管束内部沿管表面周向的局部放热系数进行了研究.采用试验与数值计算相结合的方法,求得不同角度的局部放热系数,并通过数据拟合,给出Re=2×10~4～8×10~4范围内的肋管表面平均放热系数和按周向分布的局部放热系数的计算式.

LOCAL HEAT TRANSFER COEFFICIENT OF A HELICALLY SEGMENTED FINNED TUBE SURFACE

An investigation on the local heat transfer coefficient of a helically segmented finned tube surface in a tube bundle was conducted by experiment in cooperation with numerical calculation. In the experiment, the thermal couples were embedded only at an angle with the tube to be tested, then the temperature distribution around the tube was measured by revolving the tube under a certain experimental condition. On the basis of the experiment, the local heat transfer coefficients at different angles of the test tube surface for different experimental conditions were obtained by solving a set of two- dimensional finite difference equations. The results were fitted and the correlation equations for predicting the average and local heat transfer coefficients for helically finned tube in the tube bundle over the experimental range of Re = 20000-80000 were presented.