螺旋内肋扭曲管换热器性能分析及多目标优化研究
发布时间：2019-07-08 08:54
【摘要】：在管内插入物技术和异型强化换热管技术这两种强化换热技术研究的基础上,提出螺旋内肋扭曲管这种新型强化换热管。管束内部独特的螺旋内肋结构能够对近壁面区域的流体产生扰动,管束外部的螺旋扭曲形状能够使管外流体产生螺旋流动,两者均能增强流体间的混合程度,增强换热效果。采用数值模拟的方法,对螺旋内肋扭曲管换热器的管程和壳程进行传热和流阻性能的分析及多目标优化研究。主要的工作内容和结论如下:(1)对螺旋内肋扭曲管、螺旋扭曲管和圆管的传热流阻性能进行对比分析,得出螺旋内肋扭曲管具有优于螺旋扭曲管和圆管的综合换热性能。在雷诺数Re为2300~50000范围内,其努赛尔数Nu随雷诺数Re的增大而增大,最小为50.87,最大为481.33,相同雷诺数Re下始终高于螺旋扭曲管和圆管;其阻力系数f随雷诺数Re的增大而减小,最小为0.043,最大为0.114,但在相同雷诺数Re下高于螺旋扭曲管和圆管;其等泵功准则下的综合评价指标PEC随雷诺数Re的增大而减小,最小为1.15,最大为1.62,相同雷诺数Re下始终高于螺旋扭曲管;其热势容差-火积变化量ΔE随雷诺数Re的增大而减小,相同雷诺数Re下始终高于螺旋扭曲管和圆管。(2)对螺旋内肋扭曲管进行单因素变量分析,得出螺旋内肋扭曲管在长半轴a为11~14mm、导程s为100~250mm、肋高h为0.6~1.2mm、肋角c为60°~150°、肋数n为4~16范围内,其换热管内综合换热性能随长半轴a的增大而增大,随导程s的增大而减小,随肋高的增大而增大,随肋角的增大而减小,随肋数的增大而增大。(3)对螺旋内肋扭曲管进行基于遗传算法的多目标优化研究,综合考虑结构参数长半轴a、导程s、肋角c和流动参数v对其传热流阻性能的影响,得到其最优参数组合为长半轴a为12.28mm、导程s为140.17mm、肋角c为103.15°、进口速度v为2.77m/s,其努赛尔数Nu为661.69、阻力系数f为0.045、综合评价指标PEC为1.70。(4)对由7根螺旋内肋扭曲管组成的螺旋内肋扭曲管换热器壳程进行单因素变量分析,得出在长轴A为27~33mm、导程S为100~250mm范围内,其壳程综合换热性能随长轴A的增大而增大,随导程S的增大而减小。(5)对螺旋内肋扭曲管换热器壳程进行基于遗传算法的多目标优化,综合考虑结构参数长半轴a、导程s和流动参数v对其传热流阻性能的影响,得到其最优的参数组合为长半轴a为15.86mm、导程s为139.98mm、壳程进口速度v为1.17m/s,其壳程努赛尔数Nu为128.06、阻力系数f为0.060、综合评价指标η为326.18。
[Abstract]:Based on the research of tube insertion technology and special-shaped enhanced heat transfer pipe technology, a new type of enhanced heat transfer pipe, spiral inner ribbed twisted tube, is proposed. The unique spiral inner ribbed structure in the tube bundles can disturb the fluid near the wall, and the spiral distortion shape outside the tube bundles can make the fluid outside the tube produce spiral flow. Both of them can enhance the mixing degree between the fluids and enhance the heat transfer effect. The heat transfer and flow resistance performance of spiral inner ribbed twisted tube heat exchanger and shell side are analyzed by numerical simulation and multi-objective optimization is carried out. The main contents and conclusions are as follows: (1) the heat transfer and flow resistance of spiral inner ribbed twisted tube, spiral twisted tube and circular tube are compared and analyzed, and it is concluded that the spiral inner ribbed twisted tube has better comprehensive heat transfer performance than spiral twisted tube and circular tube. In the range of Reynolds number Re of 2300 鈮，
本文编号：2511469
[Abstract]:Based on the research of tube insertion technology and special-shaped enhanced heat transfer pipe technology, a new type of enhanced heat transfer pipe, spiral inner ribbed twisted tube, is proposed. The unique spiral inner ribbed structure in the tube bundles can disturb the fluid near the wall, and the spiral distortion shape outside the tube bundles can make the fluid outside the tube produce spiral flow. Both of them can enhance the mixing degree between the fluids and enhance the heat transfer effect. The heat transfer and flow resistance performance of spiral inner ribbed twisted tube heat exchanger and shell side are analyzed by numerical simulation and multi-objective optimization is carried out. The main contents and conclusions are as follows: (1) the heat transfer and flow resistance of spiral inner ribbed twisted tube, spiral twisted tube and circular tube are compared and analyzed, and it is concluded that the spiral inner ribbed twisted tube has better comprehensive heat transfer performance than spiral twisted tube and circular tube. In the range of Reynolds number Re of 2300 鈮，
本文编号：2511469
本文链接：https://www.wllwen.com/kejilunwen/huagong/2511469.html
