螺旋折流板与弓型折流板强化管换热器的传热性能对比

Comparison on Heat Transfer Performance of Helically Baffled Heat Exchanger with Segmentally Baffled Heat Exchanger Combined with Enhanced Tubes

以油-水换热为对象,比较了螺旋折流板与弓型折流板三维翅片管换热器的壳程传热与压降性能。试验结果表明,2台实验换热器的壳程努塞尔特常数和压降都随雷诺常数的增加而增加,但螺旋折流板三维翅片管换热器的努塞尔特常数随雷诺常数的变化更明显。在相同雷诺常数下,螺旋折流板换热器的努塞尔特常数是弓型折流板换热器的1.2～1.5倍,而压降却降低5%～12%,证明螺旋折流板三维翅片管换热器具有很高的传热强化性能。

Experiments were performed to compare the shell-side heat transfer coefficient and pressure drop of a helically baffled heat exchanger to those of a segmentally baffled heat exchanger combined with three-dimensional finned tubes for oil cooling using water as a coolant.The experimental results showed that Nusselt numbers and pressure drops increase with increasing Reynolds numbers in the shell sides for the tested heat exchangers,but the variations of Nusselt numbers were more sharp for the helically baffled heat exchanger than those of the segmentally baffled heat exchanger.The shell-side Nusselt numbers of the helically baffled heat exchanger were 1.2~1.5 times as large as those of the segmentally baffled heat exchanger,and pressure drops were reduced by 5%~12% at the same Reynolds numbers.It was proved that there was very high heat transfer enhancement performance for the helically baffled heat exchanger combined with three-dimensional finned tubes.