發(fā)布時(shí)間：2019-07-08 08:54

【摘要】：在管內(nèi)插入物技術(shù)和異型強(qiáng)化換熱管技術(shù)這兩種強(qiáng)化換熱技術(shù)研究的基礎(chǔ)上,提出螺旋內(nèi)肋扭曲管這種新型強(qiáng)化換熱管。管束內(nèi)部獨(dú)特的螺旋內(nèi)肋結(jié)構(gòu)能夠?qū)诿鎱^(qū)域的流體產(chǎn)生擾動(dòng),管束外部的螺旋扭曲形狀能夠使管外流體產(chǎn)生螺旋流動(dòng),兩者均能增強(qiáng)流體間的混合程度,增強(qiáng)換熱效果。采用數(shù)值模擬的方法,對(duì)螺旋內(nèi)肋扭曲管換熱器的管程和殼程進(jìn)行傳熱和流阻性能的分析及多目標(biāo)優(yōu)化研究。主要的工作內(nèi)容和結(jié)論如下:(1)對(duì)螺旋內(nèi)肋扭曲管、螺旋扭曲管和圓管的傳熱流阻性能進(jìn)行對(duì)比分析,得出螺旋內(nèi)肋扭曲管具有優(yōu)于螺旋扭曲管和圓管的綜合換熱性能。在雷諾數(shù)Re為2300~50000范圍內(nèi),其努賽爾數(shù)Nu隨雷諾數(shù)Re的增大而增大,最小為50.87,最大為481.33,相同雷諾數(shù)Re下始終高于螺旋扭曲管和圓管;其阻力系數(shù)f隨雷諾數(shù)Re的增大而減小,最小為0.043,最大為0.114,但在相同雷諾數(shù)Re下高于螺旋扭曲管和圓管;其等泵功準(zhǔn)則下的綜合評(píng)價(jià)指標(biāo)PEC隨雷諾數(shù)Re的增大而減小,最小為1.15,最大為1.62,相同雷諾數(shù)Re下始終高于螺旋扭曲管;其熱勢(shì)容差-火積變化量ΔE隨雷諾數(shù)Re的增大而減小,相同雷諾數(shù)Re下始終高于螺旋扭曲管和圓管。(2)對(duì)螺旋內(nèi)肋扭曲管進(jìn)行單因素變量分析,得出螺旋內(nèi)肋扭曲管在長(zhǎng)半軸a為11~14mm、導(dǎo)程s為100~250mm、肋高h(yuǎn)為0.6~1.2mm、肋角c為60°~150°、肋數(shù)n為4~16范圍內(nèi),其換熱管內(nèi)綜合換熱性能隨長(zhǎng)半軸a的增大而增大,隨導(dǎo)程s的增大而減小,隨肋高的增大而增大,隨肋角的增大而減小,隨肋數(shù)的增大而增大。(3)對(duì)螺旋內(nèi)肋扭曲管進(jìn)行基于遺傳算法的多目標(biāo)優(yōu)化研究,綜合考慮結(jié)構(gòu)參數(shù)長(zhǎng)半軸a、導(dǎo)程s、肋角c和流動(dòng)參數(shù)v對(duì)其傳熱流阻性能的影響,得到其最優(yōu)參數(shù)組合為長(zhǎng)半軸a為12.28mm、導(dǎo)程s為140.17mm、肋角c為103.15°、進(jìn)口速度v為2.77m/s,其努賽爾數(shù)Nu為661.69、阻力系數(shù)f為0.045、綜合評(píng)價(jià)指標(biāo)PEC為1.70。(4)對(duì)由7根螺旋內(nèi)肋扭曲管組成的螺旋內(nèi)肋扭曲管換熱器殼程進(jìn)行單因素變量分析,得出在長(zhǎng)軸A為27~33mm、導(dǎo)程S為100~250mm范圍內(nèi),其殼程綜合換熱性能隨長(zhǎng)軸A的增大而增大,隨導(dǎo)程S的增大而減小。(5)對(duì)螺旋內(nèi)肋扭曲管換熱器殼程進(jìn)行基于遺傳算法的多目標(biāo)優(yōu)化,綜合考慮結(jié)構(gòu)參數(shù)長(zhǎng)半軸a、導(dǎo)程s和流動(dòng)參數(shù)v對(duì)其傳熱流阻性能的影響,得到其最優(yōu)的參數(shù)組合為長(zhǎng)半軸a為15.86mm、導(dǎo)程s為139.98mm、殼程進(jìn)口速度v為1.17m/s,其殼程努賽爾數(shù)Nu為128.06、阻力系數(shù)f為0.060、綜合評(píng)價(jià)指標(biāo)η為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，

本文編號(hào)：2511469