化工进展
化工進展
화공진전
Chemical Industry and Engineering Progress
2015年
z1期
35-42
,共8页
曹海亮%黄丹%贾宝光%苏航%年志远%王定标
曹海亮%黃丹%賈寶光%囌航%年誌遠%王定標
조해량%황단%가보광%소항%년지원%왕정표
强化传热%纵向涡%计算流体力学%数值模拟
彊化傳熱%縱嚮渦%計算流體力學%數值模擬
강화전열%종향와%계산류체역학%수치모의
enhanced heat transfer%longitudinal vortices%computational fluid dynamics%numerical simulation
基于纵向涡强化换热理论提出了新型的强化换热管———弯曲内肋强化换热管。运用数值计算的方法,在Re=500~40000研究了新型强化换热管结构参数肋宽a、导程p、肋深e 和Re 数对Nu、f 及换热性能评价指标PEC的影响,并拟合出换热管Nu、f 的量纲为1关联式。结果表明：由于内肋的作用,在换热管的近壁面区域能够有效诱导产生沿纵向的涡旋结构,破坏壁面边界层,实现强化换热；导程p 和肋深e 对综合换热性能影响较大,肋宽a 对综合换热性能影响较小,在Re=500~40000范围内,新型换热管较优的结构参数为 p=10mm、e=0.6mm、a=1.8mm；与普通平滑圆管相比,当Re<2300,其换热性能Nu可达到普通圆管的2.9~7.0倍,沿程阻力系数f 约为普通圆管的1.4~3.6倍；当500<Re<2300,其综合换热评价指标 PEC可以达到2.6~4.6；当2300<Re<40000时,其PEC可以达到1.2~2.3。
基于縱嚮渦彊化換熱理論提齣瞭新型的彊化換熱管———彎麯內肋彊化換熱管。運用數值計算的方法,在Re=500~40000研究瞭新型彊化換熱管結構參數肋寬a、導程p、肋深e 和Re 數對Nu、f 及換熱性能評價指標PEC的影響,併擬閤齣換熱管Nu、f 的量綱為1關聯式。結果錶明：由于內肋的作用,在換熱管的近壁麵區域能夠有效誘導產生沿縱嚮的渦鏇結構,破壞壁麵邊界層,實現彊化換熱；導程p 和肋深e 對綜閤換熱性能影響較大,肋寬a 對綜閤換熱性能影響較小,在Re=500~40000範圍內,新型換熱管較優的結構參數為 p=10mm、e=0.6mm、a=1.8mm；與普通平滑圓管相比,噹Re<2300,其換熱性能Nu可達到普通圓管的2.9~7.0倍,沿程阻力繫數f 約為普通圓管的1.4~3.6倍；噹500<Re<2300,其綜閤換熱評價指標 PEC可以達到2.6~4.6；噹2300<Re<40000時,其PEC可以達到1.2~2.3。
기우종향와강화환열이론제출료신형적강화환열관———만곡내륵강화환열관。운용수치계산적방법,재Re=500~40000연구료신형강화환열관결구삼수륵관a、도정p、륵심e 화Re 수대Nu、f 급환열성능평개지표PEC적영향,병의합출환열관Nu、f 적량강위1관련식。결과표명：유우내륵적작용,재환열관적근벽면구역능구유효유도산생연종향적와선결구,파배벽면변계층,실현강화환열；도정p 화륵심e 대종합환열성능영향교대,륵관a 대종합환열성능영향교소,재Re=500~40000범위내,신형환열관교우적결구삼수위 p=10mm、e=0.6mm、a=1.8mm；여보통평활원관상비,당Re<2300,기환열성능Nu가체도보통원관적2.9~7.0배,연정조력계수f 약위보통원관적1.4~3.6배；당500<Re<2300,기종합환열평개지표 PEC가이체도2.6~4.6；당2300<Re<40000시,기PEC가이체도1.2~2.3。
Based on the enhanced heat transfer theory of longitudinal vortex,a novel enhanced heat transfer tube - rolled curved ribs tubes is developed.The influence of its structural parameters including rib width a,lead p,rib deep e and Re on Nu,f and the overall heat transfer performance evaluation criterion (PEC)value is studied numerically in different Re from 500 to 4×104 ,and the dimensionless correlations of Nu,f are finally obtained.The results show that a strong vortex in the longitudinal direction of the spiral is induced in the near-wall region due to the presence of the ribs,which could break boundary,in turn achieved a heat transfer enhancement.lead p and rib deep e have bigger influence than rib width a in the overall heat transfer performance;the better geometric parameters of the new tube are p=10mm,e=0.6mm,a=1.8mm.When Re<2300,the Nu of the rolled curved ribs tube can be 2.9—7.0 times than that of the smooth circular tube,correspondingly,frictional loss factor is about 1.4—3.6 times than that of the smooth circular tube.When 500<Re<2300,the overall heat transfer performance evaluation criterion (PEC)value can reach up to 2.4—4.6,and when the 2300<Re<40000,it can reach 1.2—2.3.
