Annaratone D. Handbook for Heat Exchangers and Tube Banks design
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Handbook for Heat Exchangers and
Tube Banks Design
Donatello Annaratone
Handbook for
Heat Exchangers and
Tube Banks Design
123
Prof. Donatello Annaratone
Via Ceradini 14
20129 Milano
Italy
donatello@annaratone.eu
ISBN 978-3-642-13308-4 e-ISBN 978-3-642-13309-1
DOI 10.1007/978-3-642-13309-1
Springer Heidelberg Dordrecht London New York
Library of Congress Control Number: 2010930772
© Springer-Verlag Berlin Heidelberg 2010
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Preface
The recently published book by the author, “Engineering Heat Transfer”, already
dealt with exact computation of heat exchangers and tube banks. In design com-
putation t his is accomplished via corrective factors; the latter makes it possible to
compute the actual mean temperature difference by starting from the logarithmic
one relative to fluids in parallel flow or counter flow.
As far as verification computation is concerned, corrective factors were intro-
duced to compute a certain characteristic factor correctly, as is fundamental for this
type of computation.
Based on the above, the author decided to investigate further, refine, and widen
this topic: the outcome of this work has resulted in this handbook.
New types of exchangers were examined; the calculation was refined to produce
practically exact values for the factors. The scope of the investigation was increased
by widening the range of the starting factors. Furthermore, a greater number of
values to be included in the tables was considered. Finally, a few characteristics of
certain values of the corrective factors were highlighted.
The first section is an introduction; it summarizes the fundamental criteria of heat
transfer and proceeds to illustrate the behavior of fluids in both parallel and counter
flow. It also shows how to compute the mean isobaric specific heat for some fluids;
it illustrates the significance of design computation and verification computation. In
addition, it illustrates how to proceed with heat exchangers and tube banks to carry
out both design and verification computation correctly.
Appendix A then includes 36 tables as a reference for design computation, The
tables contain the corrective factors required to obtain t he actual mean temperature
difference by starting from the mean logarithmic temperature difference relative to
fluids in parallel flow or counter flow.
Finally, Appendix B includes 35 tables for verification computation. As far as
heat exchangers are concerned, it shows the values of factor ψ which is required
for this type of computation. The values of the corrective factors for coils and tube
banks are also presented.
Milano, Italy Donatello Annaratone
v
Notation
c = specific heat (J/kgK)
d = diameter (m)
E = efficiency factor
h = enthalpy (kJ/kg)
k = thermal conductivity (W/mK)
M = mass flow rate (kg/s)
m = mass moisture percentage (%)
q = heat per time unit (W)
S = surface (m
2
)
t = temperature (
◦
C)
U = overall heat transfer coefficient (W/m
2
K)
x = thickness (m)
α = heat transfer coefficient (W/m
2
K)
β = characteristic factor
γ = characteristic factor
η = efficiency
ϕ = corrective factor
χ = corrective factor
ψ = characteristic factor
Δt = temperature difference (
◦
C)
vii
viii Notation
Superscripts
=heating fluid
= heated fluid
Subscripts
c = counter flow
e = exchanger
i = inside
l = logarithmic
m = mean
o = outside
p = constant pressure (isobaric), parallel flow
w = wall
1 = inlet (for heating or heated fluid)
2 = outlet (for heating or heated fluid)
Contents
1 Introduction to Computation ..................... 1
1.1 General Considerations ...................... 1
1.2 Mean Isobaric Specific Heat . . .................. 3
1.2.1 Water and Superheated Steam . . ............. 4
1.2.2 AirandOtherGases.................... 4
2 Design Computation .......................... 7
2.1 Introduction ............................ 7
2.2 Fluids in Parallel Flow or in Counter Flow ............ 8
2.3 The Mean Difference in Temperature in Reality . ........ 12
2.3.1 FluidsinCrossFlow.................... 14
2.3.2 Heat Exchangers ...................... 15
2.3.3 Coils ............................ 19
2.3.4 Tube Banks with Various Passages of the External Fluid . 21
3 Verification Computation ....................... 25
3.1 Introduction ............................ 25
3.2 Fluids in Parallel Flow or in Counter Flow ............ 25
3.3 Factor ψ inRealCases....................... 33
3.3.1 FluidswithCrossFlow .................. 33
3.3.2 Heat Exchangers ...................... 34
3.3.3 Coils ............................ 35
3.3.4 Tube Bank with Various Passages of the External Fluid . 37
Appendix A Corrective Factors for Design Computation ........ 39
A.1 FluidsinCrossFlow........................ 39
A.2 Heat Exchangers . . . ....................... 42
A.2.1 Heat Exchangers with 2 Passages of Internal Fluid
(Fig.2.5).......................... 42
A.2.2 Heat Exchangers with 3 Passages of Internal Fluid
(Fig.2.6).......................... 58
A.2.3 Heat Exchangers with 4 Passages of Internal Fluid
(Fig.2.7).......................... 74
A.3 Coils ................................ 84
ix