1、外文翻译 THEORETICAL INVESTIGATION OF FLUID DISTRIBUTOR IN THEINLET/ OUTLET REGION OF SHELL-SIDE OFSHELL-AND-TUBEHEAT EXCHANGER WITHLONGITUDINAL FLOW ZEN G Wen-Liang1， 2, HU Xian-ping1, DEN G Xian-h1 (1. The Key Lab. of Enhanced Heat Transfer & Energy Conservation of the Ministry of Education , SouthChi
2、na University of Technology , Guangzhou 510640 ,China ； 2. The Chemistry and Materials Department ,Hengyang Normal University , Hengyang 421001 ,China) Abstract:Presents the theoretical investigation of fluid distributor in the region of inlet/ outletof shell-side of shell-and-tube heat exchanger wi
3、th longitudinal flow in this paper . It is advanced the structural optimal mathematical model among the various structural parameters ofshell-side of heat exchanger. The model provides reference and direction not only forexperimental and numerical investigation of this problem, but also for the othe
4、r process with fluiddistribution. Key words:shell-and-tube heat exchanger； longitudinal flow ； fluid distribution ； structural optimization ； theoretical model CLC Number : TQ051. 5 Document Code:A 0 Introduction Because of such advantages as lower pressure drop of shell-side , larger logarithmic me
5、an temperature difference (LMTD) , eliminating vibration of heat-transfer tubes , and better overall heat transfer performance , shell-and-tube heat exchangers with axial flow have become more popular in various areas of industrial process comparing with shell-and-tube heat exchangers with segment b
6、affles. With the scale of industrial production devices become lager and larger , heat exchanger as a type of universal equipment in industrial process also need to satisfy the requirement of industrial process , and the heat transfer capability of heat exchanger became larger and larger . Because t
7、he length of tube of shell-and-tube heat exchanger is decided by processing technology condition, it is necessary to enlarge the diameter of shell-side in order to enlarge the heat transfer capability. With the increasing of diameter of heat exchanger and decreasing of the ratio of length and diamet
8、er ( L/ D) , shell-side fluid flow maldistributionbecame more badly and pressure drop of shell-side increased more quickly , it is not only reduce the overall heat transfer performance of heat exchanger but also induce vibration of heat-transfer tubes. These are proved by ZHOU Sen-quan1 , Chiou J .
9、P 2 , Ulrich Mohr and Horst Gelbe3 . In order to make fluid flow homo-distribution, constructing a fluid flow distributor and setting it in the region of inlet or outlet of equipment have been carried out by S. S. Mousavi, K. Hooman4 and L. Maharaj , J . Pocock , B. K.Loveday 5 . But there is no any
10、 report of fluid flow distributor about the shell-side of shell-and-tube heat exchanger with axial flow, especially the large-scale and super-large scale heat exchanger . Setting fluid distributor also has advantage and disadvantage at the same time. On one hand shell-side fluid flow maldistribution
11、 can be improved quickly, on the other hand pressure drop of shell-side be increased quickly at same time. So it is very important to develop the theoretical, numerical, and experimental investigation of fluid flow distributor of shell-and-tube heat exchanger . The purpose of this research program i
12、s to optimize structural parameter of heat exchanger, to improve shell-side fluid flow maldistribution,toreduce shell-side -pressure drop , and to enhance overall heat transfer performance , by theoretical , numerical , and experimental investigation methods respectively. In this paper, it will intr
13、oduce optimal mathematical model among the various structural parameters of heat exchanger by theoretical methods. 1 Physical Model The overall shell-side structural drawing and the position of fluid flow distributor of shell-and-tube heat exchanger with axial flow are shown as Fig. 1 (a) . Fig. 1 (
14、b) is the sketch map of shell-side flow distributor structure. In fact , it is easily to understand the fluid 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 mo
15、del which brings out the optimal punched ratio of distributor as a function of parameter of heat exchanger. The main aspects affecting the fluid flow distribution of shellside are shown as follows: (1) punched ratio of distributor ； (2) rows of crossing tubes ； (3) arrangement style of tubes ； (4) t
16、ube pitch ； (5) tube outer diameter . Fig. 1 Schematic drawing of shell side configuration of shell and tube heat exchangers with axial flow In order to express t he researched physical model more concisely, it is be treated as a rectangle heat exchanger with axial flow when we take into account the
17、 partial unit and its inlet and outlet only. The heat exchanger is made up of 36 tubes specification of 25 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 exchanger is shown in Fig. 2 (a) . Arrangement styles and parameter of tubes is shown in Fig. 2(b) . 2 Mathematical Model In order to found the mathematical model in theoreticalmethod, a theoretical analysis model must be built firstly asFig. 3. The following assumptions and illumination are
