双螺旋结构螺旋折流板换热器试验研究

螺旋折流板换热器中壳程的流动方式与单弓形结构下具有很大的差别,在采用扇形板拼接而成的螺旋折流板结构中采用双螺旋结构来布置更多的折流板,减少流体在扇形板拼接处的漏流,使壳程流体流动更接近于平推流.分别以重柴油和水作为壳程介质,对普通螺旋折流板以及双螺旋结构螺旋折流板的传热性能、阻力性能进行试验研究,发现双螺旋结构在相同Re时,阻力提高9.9%和6.15%,Nu提高14.12%和11.72%,同时可以增大单位压降的Nu.

Experimental Study of Helical Baffled Heat Exchanger with Double Helical Structure

The shell-side flow pattern in the heat exchanger with helical baffle is quite different from that in the heat exchanger with conventional segment baffle. For the helical baffle structure made up with fan-shaped plates, the construction of double helical baffle arranged in the shell-side of the heat exchanger was proposed, The arrangement of double helical baffle allows setting up more baffles in the shell-side of the heat exchanger and can reduce the leakage in the joint points of the fan-shape plates, both of these cause the shell-side flow more approaching to the plug flow, The heat transfer and pressure drop performances in the shell-side of the heat exchanger constructed with single and double helical baffle separately were studied experimentally, The results show that, when the flow medium in the shell-side is water and under the same Re number, the pressure drop and Nu number in the shell-side of the heat exchanger with double helical baffle are 9.9% and 14,12% higher than that in the shell-side of the heat exchanger with single helical baffle, respectively. When the flow medium in the shell-side is the heavy diesel oil, the pressure drop and Nu number in the shell-side of the heat exchanger with double helical baffle are 6,15% and 11,72% higher than that in the shell-side of the heat exchanger with single helical baffle, respectively, However, for both cases of using water or heavy oil as flow medium, the double helical construction can increase the heat transfer per pressure drop of the shell-side, which implies that the construction of double helical baffle can improve the economy of the heat transfer of the heat exchanger,