外文翻譯---軸流管殼式換熱器殼側(cè)流體進 出口分布擋板的理論研究

1、<p><b>　　外文翻譯</b></p><p>　　THEORETICAL INVESTIGATION OF FLUID DISTRIBUTOR IN</p><p>　　THE INLET/ OUTLET REGION OF SHELL-SIDE OF SHELL-AND-TUBE HEAT EXCHANGER WITHLONGITUDINAL FL

2、OW</p><p>　　ZEN G Wen-Liang1，2, HU Xian-ping1, DEN G Xian-h1</p><p>　　(1. The Key Lab. of Enhanced Heat Transfer & Energy Conservation of the Ministry of Education , South China University o

3、f Technology , Guangzhou 510640 ,China ; 2. The Chemistry and Materials Department ,Hengyang Normal University , Hengyang 　421001 ,China)</p><p>　　Abstract:Presents the theoretical investigation of fluid di

4、stributor in the region of inlet/ outlet of shell-side of shell-and-tube heat exchanger with longitudinal flow in this paper . It is advanced the structural optimal mathematical model among the various structural paramet

5、ers of shell-side of heat exchanger. The model provides reference and direction not only for experimental and numerical investigation of this problem, but also for the other process with fluid distribution.</p>&l

6、t;p>　　Key words: shell-and-tube heat exchanger; longitudinal flow ; fluid distribution ; structural optimization ; theoretical model</p><p>　　CLC Number : TQ051. 5 　　　　Document Code :A</p><p>

7、;　　0 　Introduction</p><p>　　Because of such advantages as lower pressure drop of shell-side , larger logarithmic mean temperature difference (LMTD) , eliminating vibration of heat-transfer tubes , and better

8、 overall heat transfer performance , shell-and-tube heat exchangers with axial flow have become more popular in various are as of industrial process comparing with shell-and-tube heat exchangers with segment baffles. Wit

9、h the scale of industrial production devices become lager and larger , heat exchanger as a type of un</p><p>　　1 　Physical Model</p><p>　　The overall shell-side structural drawing and the positi

10、on of fluid flow distributor of shell-and-tube heat exchanger with axial flow are shown as Fig. 1 (a) . Fig. 1 (b) is the sketch map of shell-side flow distributor structure. In fact , it is easily to understand the flui

11、d distributor structure as that is a specified punched ratio board punched many mini-ostioles on it from the Fig. 1 (b) . The purpose of theoretical investigation is to found a mathematical model which brings out the opt

12、imal</p><p>　　Fig. 1 　Schematic drawing of shell side configuration of shell and tube</p><p>　　heat exchangers with axial flow</p><p>　　In order to express t he researched physical

13、model more concisely, it is be treated as a rectangle heat</p><p>　　exchanger with axial flow when we take into account the partial unit and its inlet and outlet only. The</p><p>　　heat exchange

14、r is made up of 36 tubes specification of φ25 mm ×2. 5 mm ×1 000 mm. The exterior dimension of heat exchanger is a cube wit h t he dimension of 360 mm ×120 mm ×1 000 mm. The elevation of heat exchange

15、r is shown in Fig. 2 (a) . Arrangement styles and parameter of tubes is shown in Fig. 2(b) . </p><p>　　2 　Mathematical Model</p><p>　　In order to found the mathematical model in theoretical meth

16、od, a theoretical analysis model must be built firstly as Fig. 3. The following assumptions and illumination are necessary for modeling fluid flowing through the inlet region and distributor. </p><p>　　(1)

17、 Many mini-ostioles be punched in the fluid dist ributed baffle, and diameter of mini-ostioles is infinitesimal .</p><p>　　(2) Punched ratio of distributed baffle is a continuous function with x coordinate.&

18、lt;/p><p>　　(3) Fluid flow in the x direction as shown in Fig. 3.</p><p>　　(4) Fluid flow velocity through distributed baffle is uniform.</p><p>　　Based above assumptions and next anal

19、ysis , it is easy to deduce the velocity distribution of x direction and pressure drop of x direction , z direction ,and x-z direction respectively.</p><p>　　2. 1 　Velocity dist ribution of x coordinate</

20、p><p>　　Mass balance Equation of t he infinitesimal is shown in Fig. 4 , and the differential Equation of x </p><p>　　Fig. 4 　Schematic Drawing of analyzed area</p><p>　　direction velo

21、city is obtained as Equa. (1) :</p><p><b>　　(1)</b></p><p>　　Where A x and A z denote the area of x coordinate and z coordinate , respectively.</p><p><b>　　And;<

22、;/b></p><p><b>　　(2)</b></p><p>　　The boundary condition is: x = X wit h u( x) = 0 ,so t he integral of Equa. (2) can be expressed as follows :</p><p><b>　　(3)&

23、lt;/b></p><p><b>　　(4)</b></p><p>　　2. 2 　Pressure drop of x coordinate</p><p>　　The energy balance Equation of t he infinitesimal area is shown in Fig. 4. It s diffe

24、rential Equation of</p><p>　　x direction pressure drop can be obtained as follow :</p><p><b>　　(5) </b></p><p>　　Where DH is hydraulic diameter of shell-side.</p>

25、;<p>　　The boundary condition is x = 0 wit h Δp ( x) = 0 , so t he integral of t he Equa. (5) can be expressed as :</p><p><b>　　(6)</b></p><p><b>　　(7)</b></p&g

26、t;<p>　　2. 3 　Pressure drop of x2z direction</p><p>　　According to distribution and local flow pressure drop of fluid flow from x direction turn to z direction , we can obtain it s local pressure drop

27、 Equation as follow :</p><p><b>　　(8)</b></p><p>　　2. 4 　Pressure drop of z coordinate</p><p>　　According to the generic Equation of local pressure drop of fluid , we ca

28、n obtain it s local pressure</p><p>　　drop Equation of fluid flow through mini2ostioles of distributor baffle in z direction as follow :</p><p><b>　　(9)</b></p><p>　　Whe

29、re A ( x) denote punched ratio as a f unction of independent variable x.</p><p>　　2. 5 　Homo-distribution Equation</p><p>　　It is well known that t he condition of homo-distribution of fluid flo

30、w through distributor baffle can be deduced by mechanical energy balance Equation from inlet to cross section of outlet . The basic homo-distribution Equation is shown as follow :</p><p><b>　　(10) <

31、/b></p><p>　　2. 6 　Analysis and solution</p><p>　　Combining Equa.(7) , (8) , (9) with Equa. (10) , it will obtain the following Equation :</p><p><b>　　(11)</b></p&

32、gt;<p>　　When x = X ,t hen it can be deduced the pressure drop of boundary condition :</p><p><b>　　, and </b></p><p>　　Putting the pressure drop under x = X into Equa. (10) ,

33、 then it can be deduced the following Equation :</p><p><b>　　(12)</b></p><p>　　Associating with Equa. (11) and Equa. (12), and simplifying expression , t hen it can be deduced the fo

34、llowing Equation :</p><p><b>　　(13)</b></p><p>　　Under the ideal model, optimal punched ratio can be expressed as follow :</p><p><b>　　(14)</b></p>&l

35、t;p>　　3 　Mathematical Model of In-line-square Aligned Tube Bundle</p><p>　　For the in-line-square aligned tube bundle of shell-side of shell-and-tube heat exchanger, we define</p><p>　　as tub

36、e pitch , d as outer diameter , and L as installation distance. So tube rows of shell-side under in-line-square aligned can be expresses as ,: , and putting them into Equa. (4), then the velocity of x direction can be ex

37、pressed as : (15)</p><p>　　According to the Equa. (7), (8) , and (9) , the pressure drop of x direction , x-z direction , and z direction at in-line-square aligned condition of shell-side can als

38、o be written as Equa. (16), (17) and (18) ,respectively :</p><p><b>　　(16)</b></p><p>　　Where denotes local pressure drop coefficient of crossing a t ube at t he in-line-square alig

39、ned.</p><p><b>　　(17) </b></p><p><b>　　(18)</b></p><p>　　Put ting Equa. (16) , (17) and (18) into Equa. (10), it can be deduced as follow.</p><p

40、><b>　　(19)</b></p><p>　　When x = X , it can be deduced t he pressure drop of boundary condition as follow :</p><p><b>　　, and </b></p><p>　　And p ut ting

41、 t hem into Equa. (10) , then it can be deduced the following Equation :</p><p><b>　　(20)</b></p><p>　　Associating with Equa. (19) and Equa. (20), and simplifying expression , t hen

42、it can be deduced following Equation :</p><p><b>　　(21)</b></p><p>　　Under the in-line-square aligned tube bundle of shell-side of shell-and-tube heat exchanger, optimal punched rati

43、o of fluid dist ributor in the inlet or outlet region can be expressed as follow :</p><p><b>　　(22)</b></p><p>　　In Equa. (15) to Equa. (21), A z and A x can be expressed as follows

44、:</p><p><b>　　(23)</b></p><p><b>　　(24) </b></p><p>　　It define ,and denote the ratio of out diameter of tube to tube pitch , putting it and Equa. (23)and (2

45、4) into Equa. (22) ,it will be deduced follow Equation</p><p><b>　　(25) </b></p><p>　　From Equa. (25), it has been shown that the optimal punched ratio of fluid distributor related t

46、o many factors which can be classified into two aspect s. One aspect is struct ural parameter of heat exchanger of shell-side such as out-diameter of tube, tube pitch , rows of tube buddle , cut length of distributor, an

47、d tube arrangement style. The other aspect is operating characteristic such as Reynolds number which can changer local pressure drop coefficient.</p><p>　　Although a mathematical model of shell-side fluid fl

48、ow homo-distribution be found , and the model shows the relationship of optimal punched ratio to structural parameter of heat exchanger and operating characteristic , but its correctness need to be validated by numerical

49、 and experimental methods. Future investigation will go on in numerical and experimental methods respectively.</p><p>　　4 　Conclusions</p><p>　　Through founding mathematical model and above anal

50、ysis, it is concluded as following :</p><p>　　(1) For the in-line-square aligned tube bundle of shell-side , main factors of fluid flow maidist -ribution are as such punched ratio of distributor , out-diamet

51、er of tube , tube pitch , rows of tube buddle , cut length of distributor , and tube arrangement style.</p><p>　　(2) According to Equa. (25), it is easy to design a optimal fluid flow dist ributor .</p>

52、;<p>　　(3) The pressure drop of shell-side is cube of rows which fluid cross flowed. To decrease pressure</p><p>　　drop of shell-side must decrease rows of fluid cross flowed.</p><p>　　Re

53、ferences</p><p>　　[ 1 ] Zhou Sen2Quan. The analysis of heat exchanger performance wit h temperature nonuniformity of inlet [J ] . Gongcheng Rewuli Xue-bao , 1994 ,15 (4) :8211.</p><p>　　[2 ] Chi

54、ou J . P. . The effect of nonuniformity of inlet fluid temperature on t he t hermal performance of cross-flow heat exchanger [ C] .Proc. of 7th international heat transfer conf . , 1982 :1792126.</p><p>　　[

55、3 ] Ulrich Mohr , Horst Gelbe. Velocity dist ribution and vibration excitation in tube bundle heat exchangers[J ] . Int . J . Thermal . Science. ,2000 ,39 (4) :4142421.</p><p>　　[ 4 ] S. S. Mousavi , K. Hoom

56、an. Heat and fluid flow in ent rance region of a channel with staggered baffles[J ] . Energy Conversion and Management ,2006 , 47 (18) :2 01122 019.</p><p>　　[ 5 ] L. Maharaj , J . Pocock , B. K. Loveday. Th

57、e effect of dist ributor configuration on the hydrodynamics of t he teetered bed separator</p><p>　　軸流管殼式換熱器殼側(cè)流體進/ 出口分布</p><p><b>　　擋板的理論研究</b></p><p>　　曾文良1 ,2 , 胡顯平1 ,

58、 鄧先和1</p><p>　　(1. 華南理工大學(xué)傳熱強化與過程節(jié)能教育部重點實驗室, 廣東廣州　510640 ;2. 衡陽師范學(xué)院化學(xué)與材料科學(xué)系, 湖南衡陽　421001)</p><p>　　摘　要:大型、超大型殼程軸流管殼式換熱器殼側(cè)流體的流動分布不均嚴重影響著換熱器的整體傳熱性能,而在殼側(cè)入口和出口位置安裝流體分布擋板是解決這一問題的方法之一. 文中從流體分布擋板的影響參數(shù)入手

59、,從理論上推導(dǎo)了擋板的開孔率與各種結(jié)構(gòu)參數(shù)之間的數(shù)學(xué)模型,并且推導(dǎo)出優(yōu)化的擋板設(shè)計參數(shù)方程,為殼側(cè)流體的實驗研究與數(shù)值研究提供了參考與方向.</p><p>　　關(guān)鍵詞:管殼式換熱器; 軸向流; 流體分布; 結(jié)構(gòu)優(yōu)化; 理論模型</p><p>　　中圖分類號: TQ051. 5 　　　　文獻標識碼:A</p><p>　　0 介紹 由于這些優(yōu)勢，降低殼程，大

60、對數(shù)平均溫差（數(shù)平均溫差）壓力下降，消除了傳熱管的振動，更好的整體傳熱性能，軸向流管殼式換熱器與部分擋板殼式換熱器相比在各種工業(yè)生產(chǎn)中變得更加受歡迎。隨著工業(yè)生產(chǎn)設(shè)備的規(guī)模變得越來越大，換熱器作為一種工業(yè)生產(chǎn)通用設(shè)備，還需要滿足工業(yè)生產(chǎn)過程的要求，以及換熱器傳熱能力越來越大。由于對殼管式換熱器管的長度是由加工工藝條件決定，有必要擴大殼端直徑，以擴大傳熱能力。隨著換熱器的直徑的增大和長徑比的減?。↙/D），殼程流體流動分布不均變得更難以控

61、制和殼層的壓力降增長的更快，這不僅降低了換熱器整體傳熱性能，而且也引起了傳熱管的振動。這些都是被ZHOU Sen-quan ，Chiou J . P ，Ulrich Mohr and Hor st Gelbe證明的。為了使流體流動同源分布，S. S. Mousavi , K. Hooman and L. Maharaj , J . Pocock , B. K.Loveday已經(jīng)構(gòu)建了一個流體流動分布結(jié)構(gòu)并將其設(shè)置在設(shè)備的進出口區(qū)域。但

62、沒有任何有關(guān)軸流管殼式換熱器流體流動分布的報告，特別是大規(guī)模和超大規(guī)模換熱器。</p><p>　　管殼殼端配置與軸流式換熱器示意圖1為了表達研究的物理模型更簡潔，當(dāng)我們考慮到部分單位和其進口和出口唯一時，我們把它看作一個矩形熱處理軸流換熱器。該換熱器管子是36毫米規(guī)格，尺寸為φ25 mm ×2. 5 mm ×1 000 mm。該換熱器外觀尺寸是維立方體360毫米× 120毫米&#

63、215; 1 000毫米。該換熱器高程圖2（a）所示，布置風(fēng)格和管參數(shù)如圖2（b）所示。</p><p>　　數(shù)學(xué)模型為了找到了理論方法，數(shù)學(xué)模型理論分析模型，必須首先建立如圖（3）所示。以下假設(shè)的建模和光照是通過進口和分配器區(qū)域流體流動必要的。</p><p>　　（1）許多小孔是分布在流體擋板上，小孔直徑是微不足道的。（2）分布式擋板打孔比率是一個連續(xù)x函數(shù)。（3）在x方向流體流

64、量，如圖所示3所示。（4）流體流速通過均勻分布擋板?；谏鲜黾僭O(shè)和下一步的分析，可以很容易地分別推導(dǎo)出x方向的速度分布和壓力降的x方向，z方向和x-z方向。2.1速度分布的x坐標質(zhì)量平衡方程的無窮小如圖4所示 ，差分方程的X方向的方程式：</p><p><b>　?。?） </b></p><p>　　用和分別表示X坐標和Z坐標，有</p>

65、<p><b>　?。?）</b></p><p>　　邊界條件是：x = X 和 u( x) = 0，所以方程式（2）用積分可表示為：</p><p><b>　　（3）</b></p><p><b>　?。?）</b></p><p>　　2.2 X坐標的

66、壓力降</p><p>　　無窮小面積的能量平衡方程，如圖4所示。它差分方程x方向的壓力降，可表示為： （5）</p><p>　　殼側(cè)的水力直徑，邊界條件是x = 0和Δp ( x) = 0，所以他的積分方程式（5）可以表示為：</p><p><b>　?。?）</b&g

67、t;</p><p><b>　?。?）</b></p><p>　　2.3 X-Z方向的壓力降</p><p>　　據(jù)當(dāng)?shù)亓髁糠植己土鲃拥牧黧w壓力降，由x方向轉(zhuǎn)到z方向，我們可以得到如下方程的局部壓力降：</p><p><b>　?。?）</b></p><p>　　

68、2.4 Z坐標的壓力降</p><p>　　據(jù)當(dāng)?shù)氐牧黧w壓降通用公式，我們可以得到它的流體通過的小型分流器擋板孔當(dāng)?shù)貕航捣匠淘趜方向如下：</p><p><b>　?。?） </b></p><p>　　2.5 同質(zhì)分配公式</p><p>　　眾所周知的是，同源流體通過分流器可以通過機械擋板能量平衡方程推導(dǎo)出

69、進口交叉出口段的流量分布情況。基本同質(zhì)分配公式如下所示：</p><p><b>　?。?0）</b></p><p><b>　　分析和解決方案</b></p><p>　　聯(lián)合（7），（8），（9）和（10）式，它會得到如下方程：</p><p><b>　?。?1）</b>

70、;</p><p>　　當(dāng)x = X，可以推斷壓降的邊界條件：</p><p><b>　　，和</b></p><p>　　把壓降下x = X代入方程（10），那么我們可以得出以下方程：</p><p><b>　?。?2）</b></p><p>　　聯(lián)系方程式（11）和

71、方程式（12），并簡化表達，那么可以得出以下方程：</p><p><b>　?。?3）</b></p><p>　　在理想的模型，優(yōu)化沖壓比可表示如下：</p><p>　?。?4） </p><p>　　3 數(shù)學(xué)模型在一平方米上的管束</p><p>　　對于管殼式換熱器的殼側(cè)

72、的內(nèi)插管束，我們定義為管束管間距，d為外徑和為安裝距離。因此殼下側(cè)管排線，方形排列，可表示為：,，并把它們代入方程式（4），則x方向的速度可以表示為：</p><p><b>　?。?5）</b></p><p>　　根據(jù)方程式（7），（8），（9），壓降的x方向，x-z方向和z方向在內(nèi)插管束對齊殼側(cè)方向的條件也可以分別寫成方程式（16），（17）和（18）：<

73、/p><p>　　（16） </p><p>　　其中表示當(dāng)?shù)貕航翟诠苁€一方對齊的管系數(shù)</p><p><b>　　（17）</b></p><p><b>　?。?8）</b></p><p>　　把（16）（17）（18）式代入方程（10）式，可簡化得到：<

74、;/p><p><b>　?。?9）</b></p><p>　　當(dāng) x = X 時，可以推導(dǎo)出如下的邊界條件壓降：</p><p><b>　　, and </b></p><p>　　將他們代入方程（10）可得到下式：</p><p><b>　?。?0）<

75、/b></p><p>　　聯(lián)合方程式（19）和方程式（20），簡化表達，可以推斷公式如下：</p><p><b>　?。?1）</b></p><p>　　根據(jù)該對齊殼的管殼式換熱器管束方，最佳流體的分配比例，進口或出口區(qū)域可表示如下：</p><p><b>　?。?2） </b><

76、;/p><p>　　從方程（15）式到方程（21）， </p><p><b>　　（23）</b></p><p><b>　?。?4）</b></p><p>　　定義，表示管內(nèi)管直徑與管間距之比，把它和方程式（23）（24）代入方程式（22），可得妻方程如下：</p><p&g

77、t;<b>　?。?5）</b></p><p>　　從方程式（25）看出，它已被證明是最佳的流體分配沖壓比，有關(guān)的很多因素可劃分為兩個方面。一個方面是熱殼側(cè)換熱器結(jié)構(gòu)參數(shù)，如外管直徑，管間距，管的排列，分流結(jié)構(gòu)切割長度，管安排的風(fēng)格。另一個方面是操作特性，如雷諾數(shù)可兌換當(dāng)?shù)貕航迪禂?shù)。</p><p>　　雖然殼側(cè)流體流動同源分布的數(shù)學(xué)模型已經(jīng)發(fā)現(xiàn)，以及模型顯示了最佳

78、的比例關(guān)系，以沖壓換熱器結(jié)構(gòu)參數(shù)和運行特點，但它的正確性，需要通過數(shù)值和實驗方法驗證。調(diào)查將會分別用數(shù)值和實驗方法繼續(xù)進行。</p><p><b>　　總結(jié)</b></p><p>　　通過建立數(shù)學(xué)模型和上述分析，可以得出結(jié)論如下：</p><p>　　（1）對于管束對齊殼側(cè)，流體流動的主要因素是外管直徑，管間距，管束排列，分流結(jié)構(gòu)切割長度，