扇形内翅片石墨管层流强化传热性能

利用数值模拟方法对一种高黏度的油类介质在6种不同布置交错角度(0°,30°,45°,60°,75°,90°)的扇形内翅片石墨换热管中层流的强化传热和流动规律进行了研究.结果表明,扇形内翅片的强化换热效果明显.与无翅片的石墨换热管相比,6种布置角度的扇形内翅片对流换热系数分别增大22.69%,42.49%,62.28%,63.44%,65.47%,66.47%.就流动性能而言,扇形内翅片的石墨管6种布置角度下的阻力分别增大了191.88%,252.01%,333.10%,364.33%,385.51%,400.43%.为了明确石墨管内添加扇形内翅片后的强化传热效应,采用了换热性能评价指标(PEC)对6种布置角度进行了评价研究,结果显示45°布置角度时PEC评价准则数的平均值达到最大,为1.265,说明布置角度为45°时强化换热效果最理想.

Laminar Heat Transfer Enhancement of Graphite Tube with Internal Fan Shaped Fins

Abstract： Numerical investigation of different fin angles (0°, 30°, 45°, 60°, 75°, 90°) was conducted to analyze the flow mechanism and heat transfer characteristics of high viscosity oil medium in graphite tube with internal fan shaped fins. The simulation results show that heat transfer enhancement is significant. Over the range of the Reynolds number studied, the Nusselt number at different arrangement angles (0°, 30°, 45°, 60°, 75°, 90°) is 22.69%,42.49%,62.28%,63.44%,65.47% and 66.47% higher than that for graphite tubes without internal fan shaped fins, respectively. The flow resistance for the tube with fins are found increasing by 191.88%,252.01%,333.10%,364.33%,385.51% and 400.43%, respectively. The evaluation index PEC has been introduced for the comparison of six different arrangement angle fins. The results show that the integral average PEC at 45° achieves a maximum value of 1.265 and that when the arrangement angle of fins is 45°, the graphite tubes with internal fan shaped fins has the best thermal and flow performance.