Shell and Tube Heat-Exchanger-Design
Shell and Tube Heat-Exchanger-Design
Shell and Tube Heat-Exchanger-Design
International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering Vol:2, No:10, 2008
AbstractThis paper is intended to assist anyone with some With the help of this computer program, not only the shell
general technical experience, but perhaps limited specific and tube heat exchanger can be designed without knowing the
knowledge of heat transfer equipment. A characteristic of heat detail design calculation but also plant engineer can modify
exchanger design is the procedure of specifying a design, heat the currently used heat exchanger for some necessary changes,
transfer area and pressure drops and checking whether the such as blocking the blown out tubes without much effects to
assumed design satisfies all requirements or not. The purpose operation, changes in fluid flow rate according to other
of this paper is how to design the oil cooler (heat exchanger) process, etc.
especially for shell-and-tube heat exchanger which is the It is hoped that this paper will aid in classifying the many
majority type of liquid-to-liquid heat exchanger. General details questions that arise during design calculation and this
International Science Index, Mechanical and Mechatronics Engineering Vol:2, No:10, 2008 waset.org/Publication/7663
design considerations and design procedure are also illustrated will support practicing engineers to apply the formal
in this paper and a flow diagram is provided as an aid of backgrounds in fluid flow and heat transfer to the practical
design procedure. In design calculation, the MatLAB and problems posed by the design, selection, testing, or installation
AutoCAD software are used. Fundamental heat transfer of the shell and tube heat exchanger.
concepts and complex relationships involved in such
exchanger are also presented in this paper. The primary aim of II. DESIGN CONSIDERATION
this design is to obtain a high heat transfer rate without
exceeding the allowable pressure drop. This computer The designer must consider several factors that influence
program is highly useful to design the shell-and-tube type heat the shell-side heat transfer coefficient that, in turn, determine
exchanger and to modify existing deign. the rate of heat transfer in the shell-side.
1. When baffles are provided, the system directs the
KeywordsShell-and-Tube Heat Exchanger, MatLAB and shell-fluid from axial flow to top-to-bottom flow or
AutoCAD side-to-side flow with the effect that the heat transfer
coefficient is higher than for undisturbed flow along
I. INTRODUCTION the axes of the tubes [2].
2. Patterns of tube layout influence turbulence and
International Scholarly and Scientific Research & Innovation 2(10) 2008 1151 scholar.waset.org/1999.8/7663
World Academy of Science, Engineering and Technology
International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering Vol:2, No:10, 2008
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World Academy of Science, Engineering and Technology
International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering Vol:2, No:10, 2008
smaller in size and have smaller or equal pressure drops as For Laminar flow,
conventional plain tube units [7]. 1/ 3
hd d
Nu = = 1.86 Re.Pr 0.14 (6)
k L
For Transistion flow,
hd d 2/3
Nu = = 0.116(Re2/3 125) Pr1/ 3 0.14 1 + (7)
k L
For Turbulent flow,
hd
Nu = = 0.023 Re 0.80 . Pr 1/ 3 0.14 (8)
k
The criterion of distinguishing between laminar and
turbulent flow is the observed mixing action. Nusselt number
(Nu) is a function of Reynolds number (Re) and Prandtl
number (Pr). Nu of the flow inside tube can then be calculated
International Science Index, Mechanical and Mechatronics Engineering Vol:2, No:10, 2008 waset.org/Publication/7663
an = at-a f (5)
Where, at is tube cross flow area, af is tip area of plate fin,
an is the net flow area for one tube. To calculate tube-side flow
passage area for one pass, an is multiplied by Nt/one pass. And
then, calculate tube side mass flow rate G1. Fig. 5 Single-segmental Shell and Tube Heat Exchanger Showing Baffle
After that, Reynold number of the flow inside tube can then Spacing [8]
be calculated by the following equations.
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International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering Vol:2, No:10, 2008
a3
a= (30)
1 + 0.14Re a 4
For heat load check, the overall heat transfer
coefficient, U, can be achieved from (31).
1 (31)
International Science Index, Mechanical and Mechatronics Engineering Vol:2, No:10, 2008 waset.org/Publication/7663
Uo =
ro 1 1 ro ro 1 1
+ + ln + +
r
i ih h si k r
w i h so h o
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International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering Vol:2, No:10, 2008
V. CASE STUDY
A transmission oil cooler is designed according to the
MatLAB program discussed above.
TABLE I
International Science Index, Mechanical and Mechatronics Engineering Vol:2, No:10, 2008 waset.org/Publication/7663
2w
0.001m
p w = N b (2 + 0.6N tcw ) R L R (47) 6000
Where M is the shell-side flow rate in kg/s and pw and mw Fig. 9 A fact of Reynolds Number on Number of Tubes
are the pressure drop and mass velocity in all Nb window
zones for turbulent flow (Re>100).
N
p e = p bl 1 + tcw R B R S (48)
N tcc
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1500 11000
Heat Transfer Coefficient in Tube (W/m K)
10000
2
1400
9000
32000
260
Heat Load (kW)
30000 Nb=2
250
Nb=3
28000 Nb=4 240
26000 230
Reynolds Number in Shell
24000 220
Nb=2
210
22000 Nb=3
Nb=4
200
20000 300 310 320 330 340 350 360 370 380 390 400
Shell Diameter (mm)
18000
Fig. 13 A fact of Heat Load on Shell Diameter
16000
International Scholarly and Scientific Research & Innovation 2(10) 2008 1157 scholar.waset.org/1999.8/7663
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International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering Vol:2, No:10, 2008
REFERENCES
[1] Frass, A.P and M.Necatic Ozisik, 1965, Heat Exchanger Design, John
Wiley and Sons Inc.
[2] Max S.Peters and Klaus D. Timmerhuaus, 1958, Plant Design and
Economics for Chemical Engineers, 4th ed, McGraw-Hill Book
Company.
[3] TEMA, 1999, Standards of TEMA, 8th ed, Turbular Exchanger
Manufacturers Association, New York.
[4] Kays, W.M and A.L.London, 1998, Compact Heat Exchangers, 3rd ed,
Krieger Publishing Malabar, FL.
[5] E.A.Krasnoshchekov and A.S.Sukomel, 1977, Problems in Heat
Transfer, MIR Publishers, Moscow.
[6] Professor John R.Thom, 2004, Wolverine Tube Heat Transfer Data
Book III, Wolverine Tube Inc, www.Wolverine.com.
[7] J.P. Holman, 1963, Heat Transfer, 8th ed, McGraw-Hill Book Company.
[8] Dr. K. J. Bell and Dr. A.C.Muller, 1984, Wolverine Tube Heat
Transfer Data Book II, Wolverine Division of UOP Inc,
www.Wolverine.com.
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