SlideShare a Scribd company logo
1 of 12
Download to read offline
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
62
An Improved Method for Predicting Heat Exchanger Network
Area
Mohammed Awwalu USMAN
Department of Chemical Engineering, University of Lagos, Lagos 101017, Nigeria
Email: mawwal04@yahoo.com; musman@unilag.edu.ng; Tel: 2348023186445
ABSTRACT
Successful application of pinch analysis to any process, be it for grassroots design or retrofit, depends upon the
extent to which set targets are achieved in practice. This entails predicating the three stages of process
integration namely targeting, synthesis and detailed design on the same basis. There exist gap between these
three stages largely due to inaccuracies in film heat transfer coefficient and inability to replicate same at the
various stages. This paper presents an improved methodology for area targeting that is consistent with detailed
design of an exchanger not just because it is premised on the same basis of pressure drop constraints but, more
importantly, because it allows, for necessary variation of stream properties with temperature. The validity of the
methodology has been tested using two case studies from the literature. The results obtained in all studies reveal
a difference of less than 2% between targeting, synthesis and detailed design with the new methodology. This is
contrary to the difference of as high as 59% between targeting and detailed design obtained with the state-of-the-
art methodology. There is therefore an excellent agreement between the three stages of process integration
arising from the new methodology.
Keywords: heat exchanger network, area targeting, synthesis, detailed design, pressure drop, film heat transfer
coefficient.
1. Introduction
Process integration for energy recovery has remained topical to researchers and industries alike because of
economic and environmental concerns. Grassroot designs and retrofit of existing plants have been accomplished
using either pinch analysis or mathematical programming or both to achieve maximum energy recovery amongst
process streams and reduce utility consumption. Pinch analysis provides insights on network design and is easier
to understand and implement [Smith, 2005; Kemp, 2007, El-Halwagi, 2006]. Some recent studies implement
pinch analysis solely [Li and Chang, 2010; Promvidak et al., 2009; Nejad et al., 2012; Bakhtiari and Bedard,
2013; Feng et al., 2011]. On the hand, mathematical programming is characterized by high accuracy and
computational effectiveness but dogged by huge computational effort and little insight on network design as ev
ident in reported studies [El-Halwagi, 2006; Fieg et al., 2009; Zhang and Rangaiah, 2013; Ponce-Ortega at al.,
2008, 2010; Nguyen et al., 2010; Rezaei and Shafiei, 2009; Luo et al., 2013; Bogataz and Kravanja, 2012;
Laukkanen et al., 2012; Escobar and Trierweiler, 2013; Jezowski et al., 2003; Shethna et al, 2000; Ciric and
Floudas, 1990]. Some studies exploit the synergy of both pinch analysis and mathematical programming
[Beninca et al., 2011; Jiang et al., 2011]. However, pinch analysis remained very attractive to engineering
practitioner due its simplicity. This therefore inform incessant quest for its improvement.
Though energy saving is the main thrust of process integration, area requirement is equally important since
desired energy recovery must necessarily be accomplished in a heat exchanger. The determination of optimum
minimum temperature difference (∆T min) also depends upon correct predictions of capital cost, which is a
direct function of area requirement. Thus, an accurate estimation of area is very crucial to process integration in
the synthesis of heat exchanger network (HEN). This is true for both grassroots design and retrofit of an already
existing network. Hence, any inaccuracies in area prediction will prejudice the optimisation of ∆Tmin leading to
a suboptimal network.
The state-of-the-art procedure for area estimation is based on film heat transfer coefficient (h). This would have
been okay if h was a property that could be replicated wherever the stream finds itself. However, this is not the
case since h is a function of both physical properties and flow configuration. Thus, the film heat transfer
coefficient obtained for a stream during detailed network design is in most cases widely different from that upon
which the network targeting and synthesis are based. This creates a gap between the three stages of process
integration namely, targeting, synthesis and detailed network design that could undermine the envisaged gains.
The other drawback of the present area prediction algorithm is that is has no consideration for the flow
arrangement already in existence. This is especially true for retrofit. Therefore the extra cost of pipings and
pumps that may be necessitated by the process modification could make non-sense of the process integration.
Previous studies have attempted to address some of these shortcomings of area prediction in various ways [Sun
et al., 2013; Jiang et al., 2011; Wan Alwi and Manan, 2010; Serna and Jimanez, 2004; Zhu et al., 1995a, 1995b].
However, they neither acknowledge nor attempt to redress the aforementioned gap. Moreso, most of the
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
63
available softwares are still based on film heat transfer coefficient [Lam et al., 2011].
This work presents an improved methodology for area estimation that seeks to bridge the gap between network
targeting, synthesise and detailed exchanger design. The necessary relation between film heat transfer coefficient
and pressure drop for the tube side and the shell side of a shell-and-tube heat exchanger will be derived giving
the underlying equation for the improved methodology. The validity of the new algorithm developed would be
tested by applying it to two case studies in the literature where the old algorithm has been found to estimate area
widely different from the area obtained during detailed exchanger design.
2. State-of-the-art methodology for network area prediction
In the existing methodology, area estimation is obtained as follows.
Figure 1: Illustrative curve for Surface Area
If it is assumed that the heating and cooling curves correspond to a single stream each, then the overall heat
transfer coefficient (U): can he estimated from
0
111
hhU i
+= (1)
Where the individual film coefficients include the fouling factors. The area of the heat exchanger is given by
LMTU
Q
A
∆
= (2)
Suppose we consider an interval I where two hot streams (1,2) are matched against two cold streams (3,4. If
stream 1 is matched with stream 3 and stream 2 with stream 4, we have two exchangers (E1 and E2 respectively).
The heat loads and the log-mean temperature driving forces for each of the exchangers will be the same. The
respective overall coefficients are:
311
111
hhUE
+= (3)
422
111
hhUE
+= (4)
The total areas is
LMELME
EET
TU
Q
TU
Q
AAA
∆
+
∆
=+=
21
21 (5)
By substituting equations 3 and 4 into equations 5 we obtain;








+++
∆
=
4321
1111
hhhhT
Q
A
LM
T ` (6)
Enthalpy: H
Temperature
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
64
If on the other hand the stream matching had been the other way round, i.e. stream 1 with 4 and stream 2 with 3,
we still obtain identical equations.
323
111
hhUE
+= (7)
414
111
hhUE
+= (8)
The total area is
LMELME
EET
TU
Q
TU
Q
AAA
∆
+
∆
=+=
43
43 (9)
That is






+++
∆
=
4321
1111
hhhhT
Q
A
LM
T (10)
This result can therefore be generalised for any number of hot and cold streams in an interval.The area in any
interval can be written as
(11)
Where NSi is the total number of streams (hot and cold) in interval i. Summing this expression over the entire
intervals gives the area requirement for a network as follows:
∑ ∑ 





∆
=
Intervals NS
iiLM
i
ett
i
hT
Q
A
1 1,
arg
1
(12)
Where
Qi = Heat load in interval I
=∆ iLMT , Logarithmic temperature difference interval I
Equation (12) is the governing equation for the state-of-the-art algorithm for area estimation [Douglas, 1988;
Towsend and Linnhoff, 1984]. Hence, the contribution of stream j to the total network area is given by
∑ 







∆
=
Interval
jLM
i
j
hT
Q
A
1
1
(13)
Equation (13) can then be rewritten in terms of stream area contributions as follows:
∑==
Stream
jettT AAA
1
arg (14)
The problem associated with the usage of film heat transfer coefficient for network are prediction especially as it
relates to process retrofit was first identified by Polley et.al., 1990. they argued that there is no systematic means
of deriving a single value that is properly representative of a stream that is involved in multiple matching. This
renders the film coefficient used for retrofit inaccurate. Secondly, they posited that pressure drop constraints is
taken for granted and this could lead to additional cost in terms of extra piping and pumping requirement. They
derived equations relating pressure drop with film coefficient for some exchange types. Polley et.al., 1991
employed their methodology, to a very large extent, is still premised on film coeffienct though with a more
accurate value. The large extent, is still premised on film coefficient though with a more accurate value. The
major flaw of their methodology is the lack of consideration for the necessary change in stream properties with
respect to temperature. Perhaps this explains why the state-of–the art procedure is still entirely based on film
coefficient.
3. Improved model
The frictional pressure drop in a heat exchanger can be related to the exchanger area and film coefficient as
follow [Polley et al. 1990]:
m
KAhP =∆ (15)
Where,
∑∑∑ =∆
=





+
∆
=
iNS
j jiLM
i
cold
jcold
hot
jhotLMi
ii hT
Q
hhT
Q
A
1,11
111
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
65
=∆P Allowable pressure drop
K= Constant solely dependent on physical properties, volumetric flow rate and a single characteristic
dimension
M= exponential constant dependent on geometry (m=3.5 for tube-side and 5.1 for shell side in a shell and
heat exchanger)
From equation (13), the contribution of stream j in interval I to the network area can be written as follows;








∆
=
ijiLM
i
ij
hT
Q
AI
,,
,
1
(16)
Applying equation (15) to a stream j in interval I yields;
m
ijijijij hACKP ,,,, =∆ (17)
Where,
Aj,I =area contribution of stream j in interval I
ACj,I =contact or physical area of stream j interval i
In order to related the two areas, the following expression has been suggested [Polley et al., 1990].
∑
∑=








+=
N
K
K
K
K
jj A
CP
CP
AAC
1
(18)
Where N is the number of opposing streams.
Let us consider again the composite curve of Figure1. Suppose we have two hot stream (1&2) and two cold
streams (3&4) in the same interval, the area contributions of each of the streams is given as follows:








∆
=
iiLM
i
hT
Q
A
,1,
1
,1
1
(19)








∆
=
iiLM
i
hT
Q
A
,2,
1
,2
1
(20)








∆
=
iiLM
i
hT
Q
A
,3,
1
,3
1
(21)






∆
=
iiLM
i
hT
Q
A
41,
1
,4
1
(22)
The pressure drops of the streams in the interval i are given by
M
iiii hACKP ,1,1,1,1 =∆ (23)
M
iiii hACKP ,2,2,2,2 =∆ (24)
M
iiii hACKP ,3,3,3,3 =∆ (25)
M
iii hACKP 1,4,4,4,4 =∆ (26)
The contact areas of the streams are
i
ii
i
i
ii
i
ii A
CPCP
CP
A
CPCP
CP
AAC ,4
,4,3
,4
,3
,4,3
,3
,1,1
+
+
+
+= (27)
i
ii
i
i
ii
i
ii A
CPCP
CP
A
CPCP
CP
AAC ,4
,4,3
,4
,3
,4,3
,3
,2,2
+
+
+
+= (28)
i
ii
i
i
ii
i
ii A
CPCP
CP
A
CPCP
CP
AAC ,2
,2,1
,2
,1
,2,1
,1
,3,3
+
+
+
+= (29)
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
66
i
ii
i
i
ii
i
ii A
CPCP
CP
A
CPCP
CP
AAC ,2
,2,1
,2
,1
,2,1
,1
,4,4
+
+
+
+= (30)
The total network area for interval i is given by
Ai=AI1,i + AI 2,I + AI 3,I + AI 4,I (31)
Equations 19-31 give a system of 13 equations in 13 unknowns. The unknowns are four, AIs ,four ACs, four hs
and Ai LMT∆ , four CPS, and A, while the known are four given by
4375.3
1
32
k
kk
K = (32)
where, for the tube-side,
3
1
8.0
1 Pr023.0 











=
µ
ρλ i
i
d
d
k (33)
p
ii
n
dd
k 











=
ρ
ρ
µ
25.0
2 1582.0 (34)
p
i
Vn
d
k
4
3 = (35)
and for the shell-side;
501
1
32
k
kk
K = (36)
3
1
55.0
1 Pr36.0 











=
µ
ρλ e
e
d
d
k (37)












=
−
e
e
d
d
k
ρ
µ
ρ
19.0
2 895.0 (38)
Vd
dPP
k
o
ott
23
)(4
Π
−
= ((39)
Thus we obtain a well defined system of non-linear algebraic equations. A similar set of equations can be written
for the other intervals of energy recovery. The total network area requirement is then given by,
∑=
Intervals
iett AA
1
arg (40)
This algorithm is pressure based and thus it is consistent with the usual basis for the necessary variations of
physical properties that normally arise from changing temperatures.
4. Method of solution
In the method of solution, it is assumed that in a network there are NI intervals and NSi streams in a given
interval. Note that NSi includes both the hot and cold stream in the interval. Writing the area contribution,
pressure drop and contact area equations for the NI intervals will give a system of 3 ∑ , non-linear
equations.
These equations can be solved by the method of successive substitution. For example, for a particular stream j in
an interval I, the algorithm is a follows
1. Guess a value of film heat transfer coefficient (h j.i
guess
)
2. Substitute (h j.i
guess
) in area contribution equation to calculate Alj.i
3. Evaluate ASCj.i from the contact area equation
4. Use the pressure drop equation to calculate hj.i denoted hj.i
cal
5. Compare (h j.i
guess
) and hj.i
cal
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
67
In order to facilitate the solution of the system of equations developed above, certain simplifying assumptions
have to be made. The most important one is the difference in the functional relationship between P and h for the
tube-side and the shell-side of a shell-and-tube heat exchanger. Certain streams will have to be consigned to the
tube-side while others are consigned to the shell-side depending on their properties. Fir grassroots application,
this does not present mush difficulty. However, in retrofit the decision has to be made from the current flow
pattern.
5. Result and discussion
5.1 Case study I
This case study is the example problem of Linnhoff ad Tjoe, 1986 depicted in Figure 2. The minimum
temperature difference in the network occurs at the hot end of exchanger 3 and its value is 32o
C. Problem table
calculations using HERO software indicate a target heating of 14,959.4 kW and cooling of 12,709.4 kW as
opposed to the current consumption values of 17,597 kW and 15,510 kW respectively. The pinch occurs at hot
stream temperature of i159o
C and at cold temperature of 1270
C. pinch modifications are them made to arrive at
the synthesised network shown in Figure 3. The state-of-the-art method is first used to estimate area for the
original network (targting) and the synthesized network. Then the newly developed methodology is employed to
do the same. Detailed design of the network is then done using Kern’s method 9,10 to estimate the realistic
network area [Kern, 1984].
The results obtained are shown in Table 1. The old methodology estimated a target area that is 59% higher than
the detailed design whole the network synthesis area is 43% higher than the detailed design. On the other hand,
the new methodology gives target area that is only 1.52 % higher than the detailed design while the synthesis
area is merely 0.3% higher than the detailed design.
Table 1: Result for case study I
Old Methodology (sq.m) This work (sq.m)
Target 3194.6 1003.2
Synthesis 1886.09 991.3
Detailed Design 1309.8 988.0
Figure 2: Base case network for case study 1
1
159
2
2000923017597
267
4
1815
13,695
5 196.1
118
H
93.3
26
20.4
88
228.577
1 C1
C2
5043 4381
2
265
127
CP(kW/K)
3
343
53.8
90
43
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
68
Figure 3: Retrofit of case study 1 by inspection
5.2 Case study II
The second study is the aromatic plant first presented in the IChemE User’s Guide [Kemp, 2007]. It used in the
form presented by Polley etal., 1991. The network is shown in Figure 4. Using a ∆T min of 25o
C, they carried
out problem table calculations and then modified the network in accordance with pinch procedure. The resulting
network is shown in Figure 5. The old procedure for area estimation yield a difference of about 43% between
targeting and detailed design and a difference of 50% between network synthesis and detailed design. The new
methodology is first employed to estimate target area and the synthesis area. Then the detailed design of the
exchangers is carried out using kern method.
Table 2 reveals a similar trend to case study I. The target and synthesis areas are 43% and 50% higher the
detailed design respectively with the old methodology. The new methodology gives target and synthesis area that
are only 1.3 and 1.8% higher than he detailed design area respectively.
Table 2: Result for case study II
Old Methodology (sq.m) This work (sq.m)
Target 12,889 8544.3
Synthesis 14,569 8595
Detailed Design 7318 8443
In both cases, the maximum difference between the target, synthesis and detailed design areas estimated by the
new methodology is less than 2%. This runs counter to the old methodology, which gives a difference of as
much as 59% between target area and actual design area. There is therefore an excellent agreement between the
three stages of process integration arising from the new methodology.
1765 kW2570 kW9230 kW
1 2
3 C
2
C
1
5
1
CP (Kw/k)
2
3 4
4
5
118265
H
11930 kW
1245 kW
5042 kW 4381 kW
159 77
267 88
343
90
26
127
228.5
20.4
53.8
93.3
196.1
15,262 kW
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
69
Figure 4: Base case network for case Study II
Temp. (C) Duty (kW) Cp (kW/C)
H1
H2
H3
H4
E4
E2E1
E6 C3
E3
E5
C2
E7 C1
C1
C2
C3
C4
C5H1
100
160
60
100
400
70
350
60
200
40
160
60
100
45
35
85
60
140
3551
127 75.5
194.2 84.2
25116
107.8
1452
154.2
327
220
220
300
160
164
130
170
300
960022400
6600
1548
20000
2334 5148
18550
108.6141.9
188
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
70
6. Conclusions
The following conclusions can be drawn from this work
1. The state-of-the-art methodology is grossly inefficient as it predicts area widely different from the
actual network area, thereby leading to suboptimal network and unrealistic predictions.
2. The new methodology synchronises the area requirement arising from the three stages of process
integration namely targeting, synthesis and detailed design as evident in the excellent agreement
between the areas estimated for the three stages.
3. The new methodology does not involve additional cost in terms of extra piping and pump requirement
since due cognisance is taken of it right at the targeting stage.
4. The new methodology is perfectly capable of handling process retrofit which had hitherto been an area
of application with much difficult and doubts.
NOMENCLATURE
A Area, m2
Ac Contact area, m2
Amin Minimum area requirement of a network, m2
Atarget Target area for a network, m2
CP Capacity flow rate, W/K
de Equivalent of the shell-side, m
dI Diameter of inner tube, in
E1,E2,E3,E4 Process heat exchangers
h Film heat transfer coefficient, W/m2
K
HEN Heat Exchanger Network
J,K,I Subscripts for the number of streams
K Physical property constant
M Exponential constant
Figure 5: Modified Network for Case Study II
Temp. (C) Duty (kW) Cp (kW/C)
H1
H2
H3
H4
E4
E2E1
E6 C3
E3
E6
C2
E7 C1
C1
C2
C3
C4
C5H1
100
160
60
100
400
70
350
60
200
40
160
60
100
45
35
85
60
140
3551
127 75.5
194.2 84.2
25116
107.8
1452
154.2
327
220
220
300
160
164
130
170
300
960020515
6600
1427
20000
2334 5148
18550
108.6141.9
197.4
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
71
np Number of tube passes
NI Number of intervals in a network
NS Number of streams
P Pressure drop, N/m2
Q Heat load, W
∆ Tlm Logarithmic mean temperature difference, K
∆ Tmin Minimum temperature difference, K
U Overall heat transfer coefficient, W/m2
K
V Volumetric flow rate of fluid, m3
/s
REFERENCES
Bakhtiari, B., Bedard, S. 2013. Retrofitting heat exchanger networks using a modified network pinch approach.
Applied Thermal Engineering, 51, 973-979.
Beninca, M., Trierweiler, J.O., Secchi, A.R. 2011. Heat integration of an olefins plant: pinch analysis and
mathematical optimization working together. Brazilian Journal of Chemical Engineering, 28(1), 101-116.
Bogataj, M., Kravanja, Z. 2012. An alternative strategy for global optimization of heat exchanger networks.
Applied Thermal Engineering, 43, 75-90.
Ciric, A.R., Floudas, C.A. 1990. A comprehensive optimization model of the heat exchanger network retrofit
problem. Heat Recovery System CHP, 10, 407-422.
Douglas, J. M. 1988. Conceptual design of chemical processes, 216-288, Mc Graw Hill, Singapore.
El-Halwaji, M. 2006. Process integration. Elsevier, London
Escobar, M., Trierweiler, J.O. 2013. Optimal heat exchanger network synthesis: A case study comparison.
Applied Thermal Engineering, 51, 801-826.
Feng, X., Pu, J., Yang, J., Chu, K.H. 2011. Energy recovery in petrochemical complexes through heat integration
retrofit analysis. Applied Energy, 88, 1965-1982.
Fieg, G., Luo, X., Jezowski, J. 2009. A monogenetic algorithm for optimal design of large-scale heat exchanger
networks. Chemical Engineering and Processing, 48, 1506-1516.
Jezowski, J.M., Shethna, H.K., Castillo, F.J.L. 2003. Area target for heat exchanger networks using linear
programming. Industrial and Engineering Chemistry Research, 42, 1723-1730.
Jiang, N., Bao, S., Gao, Z. 2011. Heat exchanger network integration using diverse pinch point and mathematical
programming. Chemical Engineering and Technology, 34(6), 985-990.
Kemp, I.C. 2007. Pinch analysis and process integration: A user guide on process integration for the efficient use
of energy. Elsevier, London.
Kern, D.Q. 1984. Process heat transfer, McGraw H ill, Singapore.
Lam, H.L., Klemes, J.J., Kravanja, Z., Varbanov, P.S. 2011. Software tools overview: process integration,
modeling and optimization for energy saving and pollution reduction. Asia-Pacific Journal of Chemical
Engineering, 6, 696-712.
Laukkanen, T., Tveit, T.M., Ojalehto, V., Miettinen, K., Fogelholm, C.J. 2012. Bilevel heat exchanger network
synthesis with an interactive multi-objective optimization method. Applied Thermal Engineering, 48, 301-316.
Li, B.H., Chang, C.T. 2010. Retrofitting heat exchanger networks based on simple pinch analysis. Industrial and
Engineering Chemistry Research, 49, 3967-3971.
Linnhoff, B,and Tjoe, T.N. 1986. Using pinch technology for process retrofit. Chemical Engineering, 93(8),47-
60.
Luo, X., Xia, C., Sun, L. 2013. Margin desin, online optimization, and control approach of a heat exchanger
network with bypasses. Computers and Chemical Engineering, 53, 102-121.
Nejad, S.H.A., Shahraki, F., Birjandi, M.R.S., Kovac Kralj, A., F. Fazlollahi, 2012. Modification of heat
exchanger network design by considering physical properties variation. Chemical and Biochemical Quarterly,
26(2), 79-87.
Nguyen, D.Q., Barbaro, A., Vipanurat, N., Bagajewicz, M.J. 2010. All-at-once and stp-wise detailed retrofit of
heat exchanger networks using an MILP model. Industrial and Engineering Chemistry Research, 49, 6080-6103.
Polley, G. T., Shahi Panjeh, M. H. 1991. Interfacing heat exchanger Network Synthesis and detailed heat
exchangers design, IchemE, 69, A6.
Polley, G.T. Shahi panjeh, M. H. and Jegede, F. O. 1990. Pressure drop considerations in the retrofit of heat
exchanger networks. IchemE, 68, part A, 2H-220.
Ponce-Ortega, J.M., Jimenez-Gutierrez, A., |Grossmann, I.E. 2008. Optimal synthesis of heat exchanger
networks involving isothermal streams. Computers and Chemical Engineering, 32(8), 1918-1942.
Ponce-Ortega, J.M., Serna-Gonzalez, M., Jimenez-Gutierrez, A. 2010. Synthesis of heat exchanger networks
with optimal placement of multiple utilities. Industrial and Engineering Chemistry Research, 49, 2849-2856.
Journal of Energy Technologies and Policy www.iiste.org
ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online)
Vol.3, No.6, 2013
72
Promvitak, P., Siemanond, K, Bunluesriruang, S., Raghareutai, V. 2009. Retrofit design of heat exchanger
networks of crude distillation unit. Chemical Engineering Transactions, 18, 99-104.
Rezaei, E., Shafiei, S. 2009. Heat exchanger networks retrofit by coupling genetic algorithm with NLP and ILP
methods. Computers and Chemical Engineering, 33, 1451-1459.
Serna, M., Jimenez, A. 2004. An area targeting algorithm for the synthesis of heat exchanger networks.
Chemical Engineering Science, 59, 2517-2520.
Shethna, H.K., Jezowski, J.M., Castillo, F.J.L. 2000. A new methodology for simultaneous optimization of
capital and operating cost targets in heat exchanger network design. Applied Thermal Engineering, 20, 1577-
1587.
Smith, R. 2005. Chemical process design and integration, John Wiley & Sons, England.
Sun, K.N., Wan Alwi, S.R., Manan Z. A. 2013. Heat exchanger network cost optimization considering multiple
utilities and different types of heat exchangers. Computers and Chemical Engineering, 49, 194-204.
Townsend, D. W. and Linnhoff, B. 1984. Surface area targets for heat exchanger networks, paper presented at
the Institution of Chemical Engineers Annual research Meeting, Bath, U.K.
Wan Alwi, S.R., Manan, Z.A. 2010. A new graphical tool for simultaneous targeting and design of a heat
exchanger network. Chemical Engineering Journal, 162, 106-121.
Zhang, H., Rangaiah, G.P. 2013. One-step approach for heat exchanger network retrofitting using integrated
differential evolution. Computers and Chemical Engineering, 50, 92-104.
Zhu, X.X., O’Neill, B.K., Roach, J.R., Wood, R.M. 1995a. A new method for heat exchanger network synthesis
using area targeting procedures. Computers and Chemical Engineering, 19(2), 197-222.
Zhu, X.X., O’Neill, B.K., Roach, J.R., Wood, R.M. 1995b. Area targeting methods for the direct synthesis of
heat exchanger networks with unequal film coefficients. Computers and Chemical Engineering, 19(2), 223-239.
This academic article was published by The International Institute for Science,
Technology and Education (IISTE). The IISTE is a pioneer in the Open Access
Publishing service based in the U.S. and Europe. The aim of the institute is
Accelerating Global Knowledge Sharing.
More information about the publisher can be found in the IISTE’s homepage:
http://www.iiste.org
CALL FOR PAPERS
The IISTE is currently hosting more than 30 peer-reviewed academic journals and
collaborating with academic institutions around the world. There’s no deadline for
submission. Prospective authors of IISTE journals can find the submission
instruction on the following page: http://www.iiste.org/Journals/
The IISTE editorial team promises to the review and publish all the qualified
submissions in a fast manner. All the journals articles are available online to the
readers all over the world without financial, legal, or technical barriers other than
those inseparable from gaining access to the internet itself. Printed version of the
journals is also available upon request of readers and authors.
IISTE Knowledge Sharing Partners
EBSCO, Index Copernicus, Ulrich's Periodicals Directory, JournalTOCS, PKP Open
Archives Harvester, Bielefeld Academic Search Engine, Elektronische
Zeitschriftenbibliothek EZB, Open J-Gate, OCLC WorldCat, Universe Digtial
Library , NewJour, Google Scholar

More Related Content

What's hot

Dynamic indoor thermal comfort model identification based on neural computing...
Dynamic indoor thermal comfort model identification based on neural computing...Dynamic indoor thermal comfort model identification based on neural computing...
Dynamic indoor thermal comfort model identification based on neural computing...Basrah University for Oil and Gas
 
CFD Analysis and Melting Performance of PCMs in Two Dimensional Sphere
CFD Analysis and Melting Performance of PCMs in Two Dimensional SphereCFD Analysis and Melting Performance of PCMs in Two Dimensional Sphere
CFD Analysis and Melting Performance of PCMs in Two Dimensional SphereIRJET Journal
 
2011 santiago marchi_souza_araki_cobem_2011
2011 santiago marchi_souza_araki_cobem_20112011 santiago marchi_souza_araki_cobem_2011
2011 santiago marchi_souza_araki_cobem_2011CosmoSantiago
 
A Review on Thermal Aware Optimization of Three Dimensional Integrated Circui...
A Review on Thermal Aware Optimization of Three Dimensional Integrated Circui...A Review on Thermal Aware Optimization of Three Dimensional Integrated Circui...
A Review on Thermal Aware Optimization of Three Dimensional Integrated Circui...IJMER
 
Computational Analysis of Heat sink or Extended Surface
Computational Analysis of Heat sink or Extended SurfaceComputational Analysis of Heat sink or Extended Surface
Computational Analysis of Heat sink or Extended SurfaceIRJET Journal
 
Overview combining ab initio with continuum theory
Overview combining ab initio with continuum theoryOverview combining ab initio with continuum theory
Overview combining ab initio with continuum theoryDierk Raabe
 
Experimental analysis of natural convection over a vertical cylinder
Experimental analysis of natural convection over a vertical cylinderExperimental analysis of natural convection over a vertical cylinder
Experimental analysis of natural convection over a vertical cylinderIAEME Publication
 
COST MINIMIZATION OF SHELL AND TUBE HEAT EXCHANGER USING NON-TRADITIONAL OPTI...
COST MINIMIZATION OF SHELL AND TUBE HEAT EXCHANGER USING NON-TRADITIONAL OPTI...COST MINIMIZATION OF SHELL AND TUBE HEAT EXCHANGER USING NON-TRADITIONAL OPTI...
COST MINIMIZATION OF SHELL AND TUBE HEAT EXCHANGER USING NON-TRADITIONAL OPTI...IAEME Publication
 
The community climate system model ccsm3
The community climate system model ccsm3The community climate system model ccsm3
The community climate system model ccsm3Absar Ahmed
 
Rlf and ts fuzzy model identification of indoor thermal comfort based on pmv ppd
Rlf and ts fuzzy model identification of indoor thermal comfort based on pmv ppdRlf and ts fuzzy model identification of indoor thermal comfort based on pmv ppd
Rlf and ts fuzzy model identification of indoor thermal comfort based on pmv ppdBasrah University for Oil and Gas
 
Possible limits of accuracy in measurement of fundamental physical constants
Possible limits of accuracy in measurement of fundamental physical constantsPossible limits of accuracy in measurement of fundamental physical constants
Possible limits of accuracy in measurement of fundamental physical constantsirjes
 
Determination of wind energy potential of campus area of siirt university
Determination of wind energy potential of campus area of siirt universityDetermination of wind energy potential of campus area of siirt university
Determination of wind energy potential of campus area of siirt universitymehmet şahin
 
Vijay Kumar Veera Book Chapter
Vijay Kumar Veera Book ChapterVijay Kumar Veera Book Chapter
Vijay Kumar Veera Book ChapterVijay Kumar
 
Comparative studies on heat transfer and fluid flow in cored brick and pebble...
Comparative studies on heat transfer and fluid flow in cored brick and pebble...Comparative studies on heat transfer and fluid flow in cored brick and pebble...
Comparative studies on heat transfer and fluid flow in cored brick and pebble...eSAT Journals
 

What's hot (18)

C502021133
C502021133C502021133
C502021133
 
Dynamic indoor thermal comfort model identification based on neural computing...
Dynamic indoor thermal comfort model identification based on neural computing...Dynamic indoor thermal comfort model identification based on neural computing...
Dynamic indoor thermal comfort model identification based on neural computing...
 
CFD Analysis and Melting Performance of PCMs in Two Dimensional Sphere
CFD Analysis and Melting Performance of PCMs in Two Dimensional SphereCFD Analysis and Melting Performance of PCMs in Two Dimensional Sphere
CFD Analysis and Melting Performance of PCMs in Two Dimensional Sphere
 
2011 santiago marchi_souza_araki_cobem_2011
2011 santiago marchi_souza_araki_cobem_20112011 santiago marchi_souza_araki_cobem_2011
2011 santiago marchi_souza_araki_cobem_2011
 
A Review on Thermal Aware Optimization of Three Dimensional Integrated Circui...
A Review on Thermal Aware Optimization of Three Dimensional Integrated Circui...A Review on Thermal Aware Optimization of Three Dimensional Integrated Circui...
A Review on Thermal Aware Optimization of Three Dimensional Integrated Circui...
 
Computational Analysis of Heat sink or Extended Surface
Computational Analysis of Heat sink or Extended SurfaceComputational Analysis of Heat sink or Extended Surface
Computational Analysis of Heat sink or Extended Surface
 
Overview combining ab initio with continuum theory
Overview combining ab initio with continuum theoryOverview combining ab initio with continuum theory
Overview combining ab initio with continuum theory
 
Experimental analysis of natural convection over a vertical cylinder
Experimental analysis of natural convection over a vertical cylinderExperimental analysis of natural convection over a vertical cylinder
Experimental analysis of natural convection over a vertical cylinder
 
COST MINIMIZATION OF SHELL AND TUBE HEAT EXCHANGER USING NON-TRADITIONAL OPTI...
COST MINIMIZATION OF SHELL AND TUBE HEAT EXCHANGER USING NON-TRADITIONAL OPTI...COST MINIMIZATION OF SHELL AND TUBE HEAT EXCHANGER USING NON-TRADITIONAL OPTI...
COST MINIMIZATION OF SHELL AND TUBE HEAT EXCHANGER USING NON-TRADITIONAL OPTI...
 
The community climate system model ccsm3
The community climate system model ccsm3The community climate system model ccsm3
The community climate system model ccsm3
 
Ijciet 10 01_169
Ijciet 10 01_169Ijciet 10 01_169
Ijciet 10 01_169
 
Rlf and ts fuzzy model identification of indoor thermal comfort based on pmv ppd
Rlf and ts fuzzy model identification of indoor thermal comfort based on pmv ppdRlf and ts fuzzy model identification of indoor thermal comfort based on pmv ppd
Rlf and ts fuzzy model identification of indoor thermal comfort based on pmv ppd
 
Possible limits of accuracy in measurement of fundamental physical constants
Possible limits of accuracy in measurement of fundamental physical constantsPossible limits of accuracy in measurement of fundamental physical constants
Possible limits of accuracy in measurement of fundamental physical constants
 
SCITECH_2015
SCITECH_2015SCITECH_2015
SCITECH_2015
 
Determination of wind energy potential of campus area of siirt university
Determination of wind energy potential of campus area of siirt universityDetermination of wind energy potential of campus area of siirt university
Determination of wind energy potential of campus area of siirt university
 
Vijay Kumar Veera Book Chapter
Vijay Kumar Veera Book ChapterVijay Kumar Veera Book Chapter
Vijay Kumar Veera Book Chapter
 
Comparison Study of Soft Computing Approaches for Estimation of the Non-Ducti...
Comparison Study of Soft Computing Approaches for Estimation of the Non-Ducti...Comparison Study of Soft Computing Approaches for Estimation of the Non-Ducti...
Comparison Study of Soft Computing Approaches for Estimation of the Non-Ducti...
 
Comparative studies on heat transfer and fluid flow in cored brick and pebble...
Comparative studies on heat transfer and fluid flow in cored brick and pebble...Comparative studies on heat transfer and fluid flow in cored brick and pebble...
Comparative studies on heat transfer and fluid flow in cored brick and pebble...
 

Similar to Improved Method for Predicting Heat Exchanger Network Area

Evaluation of Modelling of Flow in Fractures
Evaluation of Modelling of Flow in FracturesEvaluation of Modelling of Flow in Fractures
Evaluation of Modelling of Flow in Fracturesidescitation
 
Mathematical Modeling and Numerical Simulation of Selective Laser Sintering ...
Mathematical Modeling and Numerical Simulation of  Selective Laser Sintering ...Mathematical Modeling and Numerical Simulation of  Selective Laser Sintering ...
Mathematical Modeling and Numerical Simulation of Selective Laser Sintering ...IRJET Journal
 
HYDROTHERMAL COORDINATION FOR SHORT RANGE FIXED HEAD STATIONS USING FAST GENE...
HYDROTHERMAL COORDINATION FOR SHORT RANGE FIXED HEAD STATIONS USING FAST GENE...HYDROTHERMAL COORDINATION FOR SHORT RANGE FIXED HEAD STATIONS USING FAST GENE...
HYDROTHERMAL COORDINATION FOR SHORT RANGE FIXED HEAD STATIONS USING FAST GENE...ecij
 
Optimal Operation of Wind-thermal generation using differential evolution
Optimal Operation of Wind-thermal generation using differential evolutionOptimal Operation of Wind-thermal generation using differential evolution
Optimal Operation of Wind-thermal generation using differential evolutionIOSR Journals
 
V.KARTHIKEYAN PUBLISHED ARTICLE A..
V.KARTHIKEYAN PUBLISHED ARTICLE A..V.KARTHIKEYAN PUBLISHED ARTICLE A..
V.KARTHIKEYAN PUBLISHED ARTICLE A..KARTHIKEYAN V
 
V.KARTHIKEYAN PUBLISHED ARTICLE
V.KARTHIKEYAN PUBLISHED ARTICLEV.KARTHIKEYAN PUBLISHED ARTICLE
V.KARTHIKEYAN PUBLISHED ARTICLEKARTHIKEYAN V
 
Universal Engineering Model for Cooling Towers
Universal Engineering Model for Cooling TowersUniversal Engineering Model for Cooling Towers
Universal Engineering Model for Cooling TowersIJERA Editor
 
Automatic generation-control-of-multi-area-electric-energy-systems-using-modi...
Automatic generation-control-of-multi-area-electric-energy-systems-using-modi...Automatic generation-control-of-multi-area-electric-energy-systems-using-modi...
Automatic generation-control-of-multi-area-electric-energy-systems-using-modi...Cemal Ardil
 
A Novel Technique in Software Engineering for Building Scalable Large Paralle...
A Novel Technique in Software Engineering for Building Scalable Large Paralle...A Novel Technique in Software Engineering for Building Scalable Large Paralle...
A Novel Technique in Software Engineering for Building Scalable Large Paralle...Eswar Publications
 
A new approach to the solution of economic dispatch using particle Swarm opt...
A new approach to the solution of economic dispatch using particle Swarm  opt...A new approach to the solution of economic dispatch using particle Swarm  opt...
A new approach to the solution of economic dispatch using particle Swarm opt...ijcsa
 
Stochastic control for optimal power flow in islanded microgrid
Stochastic control for optimal power flow in islanded microgridStochastic control for optimal power flow in islanded microgrid
Stochastic control for optimal power flow in islanded microgridIJECEIAES
 
Uncertainty model for rate of change of frequency analysis with high renewab...
Uncertainty model for rate of change of frequency analysis with  high renewab...Uncertainty model for rate of change of frequency analysis with  high renewab...
Uncertainty model for rate of change of frequency analysis with high renewab...IJECEIAES
 
New emulation based approach for probabilistic seismic demand
New emulation based approach for probabilistic seismic demandNew emulation based approach for probabilistic seismic demand
New emulation based approach for probabilistic seismic demandSebastian Contreras
 
MILP-Based Short-Term Thermal Unit Commitment and Hydrothermal Scheduling Inc...
MILP-Based Short-Term Thermal Unit Commitment and Hydrothermal Scheduling Inc...MILP-Based Short-Term Thermal Unit Commitment and Hydrothermal Scheduling Inc...
MILP-Based Short-Term Thermal Unit Commitment and Hydrothermal Scheduling Inc...IJECEIAES
 
IRJET- Modelling and Optimization of Heat Transfer Coefficients for Hot and C...
IRJET- Modelling and Optimization of Heat Transfer Coefficients for Hot and C...IRJET- Modelling and Optimization of Heat Transfer Coefficients for Hot and C...
IRJET- Modelling and Optimization of Heat Transfer Coefficients for Hot and C...IRJET Journal
 
A novel fault location approach for radial power distribution systems
A novel fault location approach for radial power distribution  systemsA novel fault location approach for radial power distribution  systems
A novel fault location approach for radial power distribution systemsIJECEIAES
 

Similar to Improved Method for Predicting Heat Exchanger Network Area (20)

Evaluation of Modelling of Flow in Fractures
Evaluation of Modelling of Flow in FracturesEvaluation of Modelling of Flow in Fractures
Evaluation of Modelling of Flow in Fractures
 
Mathematical Modeling and Numerical Simulation of Selective Laser Sintering ...
Mathematical Modeling and Numerical Simulation of  Selective Laser Sintering ...Mathematical Modeling and Numerical Simulation of  Selective Laser Sintering ...
Mathematical Modeling and Numerical Simulation of Selective Laser Sintering ...
 
Hmtc1300663
Hmtc1300663Hmtc1300663
Hmtc1300663
 
HYDROTHERMAL COORDINATION FOR SHORT RANGE FIXED HEAD STATIONS USING FAST GENE...
HYDROTHERMAL COORDINATION FOR SHORT RANGE FIXED HEAD STATIONS USING FAST GENE...HYDROTHERMAL COORDINATION FOR SHORT RANGE FIXED HEAD STATIONS USING FAST GENE...
HYDROTHERMAL COORDINATION FOR SHORT RANGE FIXED HEAD STATIONS USING FAST GENE...
 
Optimal Operation of Wind-thermal generation using differential evolution
Optimal Operation of Wind-thermal generation using differential evolutionOptimal Operation of Wind-thermal generation using differential evolution
Optimal Operation of Wind-thermal generation using differential evolution
 
V.KARTHIKEYAN PUBLISHED ARTICLE A..
V.KARTHIKEYAN PUBLISHED ARTICLE A..V.KARTHIKEYAN PUBLISHED ARTICLE A..
V.KARTHIKEYAN PUBLISHED ARTICLE A..
 
V.KARTHIKEYAN PUBLISHED ARTICLE
V.KARTHIKEYAN PUBLISHED ARTICLEV.KARTHIKEYAN PUBLISHED ARTICLE
V.KARTHIKEYAN PUBLISHED ARTICLE
 
Universal Engineering Model for Cooling Towers
Universal Engineering Model for Cooling TowersUniversal Engineering Model for Cooling Towers
Universal Engineering Model for Cooling Towers
 
Automatic generation-control-of-multi-area-electric-energy-systems-using-modi...
Automatic generation-control-of-multi-area-electric-energy-systems-using-modi...Automatic generation-control-of-multi-area-electric-energy-systems-using-modi...
Automatic generation-control-of-multi-area-electric-energy-systems-using-modi...
 
A Novel Technique in Software Engineering for Building Scalable Large Paralle...
A Novel Technique in Software Engineering for Building Scalable Large Paralle...A Novel Technique in Software Engineering for Building Scalable Large Paralle...
A Novel Technique in Software Engineering for Building Scalable Large Paralle...
 
A new approach to the solution of economic dispatch using particle Swarm opt...
A new approach to the solution of economic dispatch using particle Swarm  opt...A new approach to the solution of economic dispatch using particle Swarm  opt...
A new approach to the solution of economic dispatch using particle Swarm opt...
 
Ijmet 06 09_006
Ijmet 06 09_006Ijmet 06 09_006
Ijmet 06 09_006
 
Stochastic control for optimal power flow in islanded microgrid
Stochastic control for optimal power flow in islanded microgridStochastic control for optimal power flow in islanded microgrid
Stochastic control for optimal power flow in islanded microgrid
 
Mine Risk Control
Mine Risk ControlMine Risk Control
Mine Risk Control
 
Uncertainty model for rate of change of frequency analysis with high renewab...
Uncertainty model for rate of change of frequency analysis with  high renewab...Uncertainty model for rate of change of frequency analysis with  high renewab...
Uncertainty model for rate of change of frequency analysis with high renewab...
 
New emulation based approach for probabilistic seismic demand
New emulation based approach for probabilistic seismic demandNew emulation based approach for probabilistic seismic demand
New emulation based approach for probabilistic seismic demand
 
MILP-Based Short-Term Thermal Unit Commitment and Hydrothermal Scheduling Inc...
MILP-Based Short-Term Thermal Unit Commitment and Hydrothermal Scheduling Inc...MILP-Based Short-Term Thermal Unit Commitment and Hydrothermal Scheduling Inc...
MILP-Based Short-Term Thermal Unit Commitment and Hydrothermal Scheduling Inc...
 
Bulk transfer scheduling and path reservations in research networks
Bulk transfer scheduling and path reservations in research networksBulk transfer scheduling and path reservations in research networks
Bulk transfer scheduling and path reservations in research networks
 
IRJET- Modelling and Optimization of Heat Transfer Coefficients for Hot and C...
IRJET- Modelling and Optimization of Heat Transfer Coefficients for Hot and C...IRJET- Modelling and Optimization of Heat Transfer Coefficients for Hot and C...
IRJET- Modelling and Optimization of Heat Transfer Coefficients for Hot and C...
 
A novel fault location approach for radial power distribution systems
A novel fault location approach for radial power distribution  systemsA novel fault location approach for radial power distribution  systems
A novel fault location approach for radial power distribution systems
 

More from Alexander Decker

Abnormalities of hormones and inflammatory cytokines in women affected with p...
Abnormalities of hormones and inflammatory cytokines in women affected with p...Abnormalities of hormones and inflammatory cytokines in women affected with p...
Abnormalities of hormones and inflammatory cytokines in women affected with p...Alexander Decker
 
A validation of the adverse childhood experiences scale in
A validation of the adverse childhood experiences scale inA validation of the adverse childhood experiences scale in
A validation of the adverse childhood experiences scale inAlexander Decker
 
A usability evaluation framework for b2 c e commerce websites
A usability evaluation framework for b2 c e commerce websitesA usability evaluation framework for b2 c e commerce websites
A usability evaluation framework for b2 c e commerce websitesAlexander Decker
 
A universal model for managing the marketing executives in nigerian banks
A universal model for managing the marketing executives in nigerian banksA universal model for managing the marketing executives in nigerian banks
A universal model for managing the marketing executives in nigerian banksAlexander Decker
 
A unique common fixed point theorems in generalized d
A unique common fixed point theorems in generalized dA unique common fixed point theorems in generalized d
A unique common fixed point theorems in generalized dAlexander Decker
 
A trends of salmonella and antibiotic resistance
A trends of salmonella and antibiotic resistanceA trends of salmonella and antibiotic resistance
A trends of salmonella and antibiotic resistanceAlexander Decker
 
A transformational generative approach towards understanding al-istifham
A transformational  generative approach towards understanding al-istifhamA transformational  generative approach towards understanding al-istifham
A transformational generative approach towards understanding al-istifhamAlexander Decker
 
A time series analysis of the determinants of savings in namibia
A time series analysis of the determinants of savings in namibiaA time series analysis of the determinants of savings in namibia
A time series analysis of the determinants of savings in namibiaAlexander Decker
 
A therapy for physical and mental fitness of school children
A therapy for physical and mental fitness of school childrenA therapy for physical and mental fitness of school children
A therapy for physical and mental fitness of school childrenAlexander Decker
 
A theory of efficiency for managing the marketing executives in nigerian banks
A theory of efficiency for managing the marketing executives in nigerian banksA theory of efficiency for managing the marketing executives in nigerian banks
A theory of efficiency for managing the marketing executives in nigerian banksAlexander Decker
 
A systematic evaluation of link budget for
A systematic evaluation of link budget forA systematic evaluation of link budget for
A systematic evaluation of link budget forAlexander Decker
 
A synthetic review of contraceptive supplies in punjab
A synthetic review of contraceptive supplies in punjabA synthetic review of contraceptive supplies in punjab
A synthetic review of contraceptive supplies in punjabAlexander Decker
 
A synthesis of taylor’s and fayol’s management approaches for managing market...
A synthesis of taylor’s and fayol’s management approaches for managing market...A synthesis of taylor’s and fayol’s management approaches for managing market...
A synthesis of taylor’s and fayol’s management approaches for managing market...Alexander Decker
 
A survey paper on sequence pattern mining with incremental
A survey paper on sequence pattern mining with incrementalA survey paper on sequence pattern mining with incremental
A survey paper on sequence pattern mining with incrementalAlexander Decker
 
A survey on live virtual machine migrations and its techniques
A survey on live virtual machine migrations and its techniquesA survey on live virtual machine migrations and its techniques
A survey on live virtual machine migrations and its techniquesAlexander Decker
 
A survey on data mining and analysis in hadoop and mongo db
A survey on data mining and analysis in hadoop and mongo dbA survey on data mining and analysis in hadoop and mongo db
A survey on data mining and analysis in hadoop and mongo dbAlexander Decker
 
A survey on challenges to the media cloud
A survey on challenges to the media cloudA survey on challenges to the media cloud
A survey on challenges to the media cloudAlexander Decker
 
A survey of provenance leveraged
A survey of provenance leveragedA survey of provenance leveraged
A survey of provenance leveragedAlexander Decker
 
A survey of private equity investments in kenya
A survey of private equity investments in kenyaA survey of private equity investments in kenya
A survey of private equity investments in kenyaAlexander Decker
 
A study to measures the financial health of
A study to measures the financial health ofA study to measures the financial health of
A study to measures the financial health ofAlexander Decker
 

More from Alexander Decker (20)

Abnormalities of hormones and inflammatory cytokines in women affected with p...
Abnormalities of hormones and inflammatory cytokines in women affected with p...Abnormalities of hormones and inflammatory cytokines in women affected with p...
Abnormalities of hormones and inflammatory cytokines in women affected with p...
 
A validation of the adverse childhood experiences scale in
A validation of the adverse childhood experiences scale inA validation of the adverse childhood experiences scale in
A validation of the adverse childhood experiences scale in
 
A usability evaluation framework for b2 c e commerce websites
A usability evaluation framework for b2 c e commerce websitesA usability evaluation framework for b2 c e commerce websites
A usability evaluation framework for b2 c e commerce websites
 
A universal model for managing the marketing executives in nigerian banks
A universal model for managing the marketing executives in nigerian banksA universal model for managing the marketing executives in nigerian banks
A universal model for managing the marketing executives in nigerian banks
 
A unique common fixed point theorems in generalized d
A unique common fixed point theorems in generalized dA unique common fixed point theorems in generalized d
A unique common fixed point theorems in generalized d
 
A trends of salmonella and antibiotic resistance
A trends of salmonella and antibiotic resistanceA trends of salmonella and antibiotic resistance
A trends of salmonella and antibiotic resistance
 
A transformational generative approach towards understanding al-istifham
A transformational  generative approach towards understanding al-istifhamA transformational  generative approach towards understanding al-istifham
A transformational generative approach towards understanding al-istifham
 
A time series analysis of the determinants of savings in namibia
A time series analysis of the determinants of savings in namibiaA time series analysis of the determinants of savings in namibia
A time series analysis of the determinants of savings in namibia
 
A therapy for physical and mental fitness of school children
A therapy for physical and mental fitness of school childrenA therapy for physical and mental fitness of school children
A therapy for physical and mental fitness of school children
 
A theory of efficiency for managing the marketing executives in nigerian banks
A theory of efficiency for managing the marketing executives in nigerian banksA theory of efficiency for managing the marketing executives in nigerian banks
A theory of efficiency for managing the marketing executives in nigerian banks
 
A systematic evaluation of link budget for
A systematic evaluation of link budget forA systematic evaluation of link budget for
A systematic evaluation of link budget for
 
A synthetic review of contraceptive supplies in punjab
A synthetic review of contraceptive supplies in punjabA synthetic review of contraceptive supplies in punjab
A synthetic review of contraceptive supplies in punjab
 
A synthesis of taylor’s and fayol’s management approaches for managing market...
A synthesis of taylor’s and fayol’s management approaches for managing market...A synthesis of taylor’s and fayol’s management approaches for managing market...
A synthesis of taylor’s and fayol’s management approaches for managing market...
 
A survey paper on sequence pattern mining with incremental
A survey paper on sequence pattern mining with incrementalA survey paper on sequence pattern mining with incremental
A survey paper on sequence pattern mining with incremental
 
A survey on live virtual machine migrations and its techniques
A survey on live virtual machine migrations and its techniquesA survey on live virtual machine migrations and its techniques
A survey on live virtual machine migrations and its techniques
 
A survey on data mining and analysis in hadoop and mongo db
A survey on data mining and analysis in hadoop and mongo dbA survey on data mining and analysis in hadoop and mongo db
A survey on data mining and analysis in hadoop and mongo db
 
A survey on challenges to the media cloud
A survey on challenges to the media cloudA survey on challenges to the media cloud
A survey on challenges to the media cloud
 
A survey of provenance leveraged
A survey of provenance leveragedA survey of provenance leveraged
A survey of provenance leveraged
 
A survey of private equity investments in kenya
A survey of private equity investments in kenyaA survey of private equity investments in kenya
A survey of private equity investments in kenya
 
A study to measures the financial health of
A study to measures the financial health ofA study to measures the financial health of
A study to measures the financial health of
 

Recently uploaded

"Federated learning: out of reach no matter how close",Oleksandr Lapshyn
"Federated learning: out of reach no matter how close",Oleksandr Lapshyn"Federated learning: out of reach no matter how close",Oleksandr Lapshyn
"Federated learning: out of reach no matter how close",Oleksandr LapshynFwdays
 
My Hashitalk Indonesia April 2024 Presentation
My Hashitalk Indonesia April 2024 PresentationMy Hashitalk Indonesia April 2024 Presentation
My Hashitalk Indonesia April 2024 PresentationRidwan Fadjar
 
Snow Chain-Integrated Tire for a Safe Drive on Winter Roads
Snow Chain-Integrated Tire for a Safe Drive on Winter RoadsSnow Chain-Integrated Tire for a Safe Drive on Winter Roads
Snow Chain-Integrated Tire for a Safe Drive on Winter RoadsHyundai Motor Group
 
Unblocking The Main Thread Solving ANRs and Frozen Frames
Unblocking The Main Thread Solving ANRs and Frozen FramesUnblocking The Main Thread Solving ANRs and Frozen Frames
Unblocking The Main Thread Solving ANRs and Frozen FramesSinan KOZAK
 
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024BookNet Canada
 
Connect Wave/ connectwave Pitch Deck Presentation
Connect Wave/ connectwave Pitch Deck PresentationConnect Wave/ connectwave Pitch Deck Presentation
Connect Wave/ connectwave Pitch Deck PresentationSlibray Presentation
 
Build your next Gen AI Breakthrough - April 2024
Build your next Gen AI Breakthrough - April 2024Build your next Gen AI Breakthrough - April 2024
Build your next Gen AI Breakthrough - April 2024Neo4j
 
AI as an Interface for Commercial Buildings
AI as an Interface for Commercial BuildingsAI as an Interface for Commercial Buildings
AI as an Interface for Commercial BuildingsMemoori
 
"LLMs for Python Engineers: Advanced Data Analysis and Semantic Kernel",Oleks...
"LLMs for Python Engineers: Advanced Data Analysis and Semantic Kernel",Oleks..."LLMs for Python Engineers: Advanced Data Analysis and Semantic Kernel",Oleks...
"LLMs for Python Engineers: Advanced Data Analysis and Semantic Kernel",Oleks...Fwdays
 
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...shyamraj55
 
#StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
#StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024#StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
#StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024BookNet Canada
 
SQL Database Design For Developers at php[tek] 2024
SQL Database Design For Developers at php[tek] 2024SQL Database Design For Developers at php[tek] 2024
SQL Database Design For Developers at php[tek] 2024Scott Keck-Warren
 
Benefits Of Flutter Compared To Other Frameworks
Benefits Of Flutter Compared To Other FrameworksBenefits Of Flutter Compared To Other Frameworks
Benefits Of Flutter Compared To Other FrameworksSoftradix Technologies
 
Bluetooth Controlled Car with Arduino.pdf
Bluetooth Controlled Car with Arduino.pdfBluetooth Controlled Car with Arduino.pdf
Bluetooth Controlled Car with Arduino.pdfngoud9212
 
Understanding the Laravel MVC Architecture
Understanding the Laravel MVC ArchitectureUnderstanding the Laravel MVC Architecture
Understanding the Laravel MVC ArchitecturePixlogix Infotech
 
costume and set research powerpoint presentation
costume and set research powerpoint presentationcostume and set research powerpoint presentation
costume and set research powerpoint presentationphoebematthew05
 

Recently uploaded (20)

Vulnerability_Management_GRC_by Sohang Sengupta.pptx
Vulnerability_Management_GRC_by Sohang Sengupta.pptxVulnerability_Management_GRC_by Sohang Sengupta.pptx
Vulnerability_Management_GRC_by Sohang Sengupta.pptx
 
"Federated learning: out of reach no matter how close",Oleksandr Lapshyn
"Federated learning: out of reach no matter how close",Oleksandr Lapshyn"Federated learning: out of reach no matter how close",Oleksandr Lapshyn
"Federated learning: out of reach no matter how close",Oleksandr Lapshyn
 
E-Vehicle_Hacking_by_Parul Sharma_null_owasp.pptx
E-Vehicle_Hacking_by_Parul Sharma_null_owasp.pptxE-Vehicle_Hacking_by_Parul Sharma_null_owasp.pptx
E-Vehicle_Hacking_by_Parul Sharma_null_owasp.pptx
 
DMCC Future of Trade Web3 - Special Edition
DMCC Future of Trade Web3 - Special EditionDMCC Future of Trade Web3 - Special Edition
DMCC Future of Trade Web3 - Special Edition
 
My Hashitalk Indonesia April 2024 Presentation
My Hashitalk Indonesia April 2024 PresentationMy Hashitalk Indonesia April 2024 Presentation
My Hashitalk Indonesia April 2024 Presentation
 
Snow Chain-Integrated Tire for a Safe Drive on Winter Roads
Snow Chain-Integrated Tire for a Safe Drive on Winter RoadsSnow Chain-Integrated Tire for a Safe Drive on Winter Roads
Snow Chain-Integrated Tire for a Safe Drive on Winter Roads
 
Unblocking The Main Thread Solving ANRs and Frozen Frames
Unblocking The Main Thread Solving ANRs and Frozen FramesUnblocking The Main Thread Solving ANRs and Frozen Frames
Unblocking The Main Thread Solving ANRs and Frozen Frames
 
The transition to renewables in India.pdf
The transition to renewables in India.pdfThe transition to renewables in India.pdf
The transition to renewables in India.pdf
 
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
 
Connect Wave/ connectwave Pitch Deck Presentation
Connect Wave/ connectwave Pitch Deck PresentationConnect Wave/ connectwave Pitch Deck Presentation
Connect Wave/ connectwave Pitch Deck Presentation
 
Build your next Gen AI Breakthrough - April 2024
Build your next Gen AI Breakthrough - April 2024Build your next Gen AI Breakthrough - April 2024
Build your next Gen AI Breakthrough - April 2024
 
AI as an Interface for Commercial Buildings
AI as an Interface for Commercial BuildingsAI as an Interface for Commercial Buildings
AI as an Interface for Commercial Buildings
 
"LLMs for Python Engineers: Advanced Data Analysis and Semantic Kernel",Oleks...
"LLMs for Python Engineers: Advanced Data Analysis and Semantic Kernel",Oleks..."LLMs for Python Engineers: Advanced Data Analysis and Semantic Kernel",Oleks...
"LLMs for Python Engineers: Advanced Data Analysis and Semantic Kernel",Oleks...
 
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...
 
#StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
#StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024#StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
#StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
 
SQL Database Design For Developers at php[tek] 2024
SQL Database Design For Developers at php[tek] 2024SQL Database Design For Developers at php[tek] 2024
SQL Database Design For Developers at php[tek] 2024
 
Benefits Of Flutter Compared To Other Frameworks
Benefits Of Flutter Compared To Other FrameworksBenefits Of Flutter Compared To Other Frameworks
Benefits Of Flutter Compared To Other Frameworks
 
Bluetooth Controlled Car with Arduino.pdf
Bluetooth Controlled Car with Arduino.pdfBluetooth Controlled Car with Arduino.pdf
Bluetooth Controlled Car with Arduino.pdf
 
Understanding the Laravel MVC Architecture
Understanding the Laravel MVC ArchitectureUnderstanding the Laravel MVC Architecture
Understanding the Laravel MVC Architecture
 
costume and set research powerpoint presentation
costume and set research powerpoint presentationcostume and set research powerpoint presentation
costume and set research powerpoint presentation
 

Improved Method for Predicting Heat Exchanger Network Area

  • 1. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 62 An Improved Method for Predicting Heat Exchanger Network Area Mohammed Awwalu USMAN Department of Chemical Engineering, University of Lagos, Lagos 101017, Nigeria Email: mawwal04@yahoo.com; musman@unilag.edu.ng; Tel: 2348023186445 ABSTRACT Successful application of pinch analysis to any process, be it for grassroots design or retrofit, depends upon the extent to which set targets are achieved in practice. This entails predicating the three stages of process integration namely targeting, synthesis and detailed design on the same basis. There exist gap between these three stages largely due to inaccuracies in film heat transfer coefficient and inability to replicate same at the various stages. This paper presents an improved methodology for area targeting that is consistent with detailed design of an exchanger not just because it is premised on the same basis of pressure drop constraints but, more importantly, because it allows, for necessary variation of stream properties with temperature. The validity of the methodology has been tested using two case studies from the literature. The results obtained in all studies reveal a difference of less than 2% between targeting, synthesis and detailed design with the new methodology. This is contrary to the difference of as high as 59% between targeting and detailed design obtained with the state-of-the- art methodology. There is therefore an excellent agreement between the three stages of process integration arising from the new methodology. Keywords: heat exchanger network, area targeting, synthesis, detailed design, pressure drop, film heat transfer coefficient. 1. Introduction Process integration for energy recovery has remained topical to researchers and industries alike because of economic and environmental concerns. Grassroot designs and retrofit of existing plants have been accomplished using either pinch analysis or mathematical programming or both to achieve maximum energy recovery amongst process streams and reduce utility consumption. Pinch analysis provides insights on network design and is easier to understand and implement [Smith, 2005; Kemp, 2007, El-Halwagi, 2006]. Some recent studies implement pinch analysis solely [Li and Chang, 2010; Promvidak et al., 2009; Nejad et al., 2012; Bakhtiari and Bedard, 2013; Feng et al., 2011]. On the hand, mathematical programming is characterized by high accuracy and computational effectiveness but dogged by huge computational effort and little insight on network design as ev ident in reported studies [El-Halwagi, 2006; Fieg et al., 2009; Zhang and Rangaiah, 2013; Ponce-Ortega at al., 2008, 2010; Nguyen et al., 2010; Rezaei and Shafiei, 2009; Luo et al., 2013; Bogataz and Kravanja, 2012; Laukkanen et al., 2012; Escobar and Trierweiler, 2013; Jezowski et al., 2003; Shethna et al, 2000; Ciric and Floudas, 1990]. Some studies exploit the synergy of both pinch analysis and mathematical programming [Beninca et al., 2011; Jiang et al., 2011]. However, pinch analysis remained very attractive to engineering practitioner due its simplicity. This therefore inform incessant quest for its improvement. Though energy saving is the main thrust of process integration, area requirement is equally important since desired energy recovery must necessarily be accomplished in a heat exchanger. The determination of optimum minimum temperature difference (∆T min) also depends upon correct predictions of capital cost, which is a direct function of area requirement. Thus, an accurate estimation of area is very crucial to process integration in the synthesis of heat exchanger network (HEN). This is true for both grassroots design and retrofit of an already existing network. Hence, any inaccuracies in area prediction will prejudice the optimisation of ∆Tmin leading to a suboptimal network. The state-of-the-art procedure for area estimation is based on film heat transfer coefficient (h). This would have been okay if h was a property that could be replicated wherever the stream finds itself. However, this is not the case since h is a function of both physical properties and flow configuration. Thus, the film heat transfer coefficient obtained for a stream during detailed network design is in most cases widely different from that upon which the network targeting and synthesis are based. This creates a gap between the three stages of process integration namely, targeting, synthesis and detailed network design that could undermine the envisaged gains. The other drawback of the present area prediction algorithm is that is has no consideration for the flow arrangement already in existence. This is especially true for retrofit. Therefore the extra cost of pipings and pumps that may be necessitated by the process modification could make non-sense of the process integration. Previous studies have attempted to address some of these shortcomings of area prediction in various ways [Sun et al., 2013; Jiang et al., 2011; Wan Alwi and Manan, 2010; Serna and Jimanez, 2004; Zhu et al., 1995a, 1995b]. However, they neither acknowledge nor attempt to redress the aforementioned gap. Moreso, most of the
  • 2. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 63 available softwares are still based on film heat transfer coefficient [Lam et al., 2011]. This work presents an improved methodology for area estimation that seeks to bridge the gap between network targeting, synthesise and detailed exchanger design. The necessary relation between film heat transfer coefficient and pressure drop for the tube side and the shell side of a shell-and-tube heat exchanger will be derived giving the underlying equation for the improved methodology. The validity of the new algorithm developed would be tested by applying it to two case studies in the literature where the old algorithm has been found to estimate area widely different from the area obtained during detailed exchanger design. 2. State-of-the-art methodology for network area prediction In the existing methodology, area estimation is obtained as follows. Figure 1: Illustrative curve for Surface Area If it is assumed that the heating and cooling curves correspond to a single stream each, then the overall heat transfer coefficient (U): can he estimated from 0 111 hhU i += (1) Where the individual film coefficients include the fouling factors. The area of the heat exchanger is given by LMTU Q A ∆ = (2) Suppose we consider an interval I where two hot streams (1,2) are matched against two cold streams (3,4. If stream 1 is matched with stream 3 and stream 2 with stream 4, we have two exchangers (E1 and E2 respectively). The heat loads and the log-mean temperature driving forces for each of the exchangers will be the same. The respective overall coefficients are: 311 111 hhUE += (3) 422 111 hhUE += (4) The total areas is LMELME EET TU Q TU Q AAA ∆ + ∆ =+= 21 21 (5) By substituting equations 3 and 4 into equations 5 we obtain;         +++ ∆ = 4321 1111 hhhhT Q A LM T ` (6) Enthalpy: H Temperature
  • 3. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 64 If on the other hand the stream matching had been the other way round, i.e. stream 1 with 4 and stream 2 with 3, we still obtain identical equations. 323 111 hhUE += (7) 414 111 hhUE += (8) The total area is LMELME EET TU Q TU Q AAA ∆ + ∆ =+= 43 43 (9) That is       +++ ∆ = 4321 1111 hhhhT Q A LM T (10) This result can therefore be generalised for any number of hot and cold streams in an interval.The area in any interval can be written as (11) Where NSi is the total number of streams (hot and cold) in interval i. Summing this expression over the entire intervals gives the area requirement for a network as follows: ∑ ∑       ∆ = Intervals NS iiLM i ett i hT Q A 1 1, arg 1 (12) Where Qi = Heat load in interval I =∆ iLMT , Logarithmic temperature difference interval I Equation (12) is the governing equation for the state-of-the-art algorithm for area estimation [Douglas, 1988; Towsend and Linnhoff, 1984]. Hence, the contribution of stream j to the total network area is given by ∑         ∆ = Interval jLM i j hT Q A 1 1 (13) Equation (13) can then be rewritten in terms of stream area contributions as follows: ∑== Stream jettT AAA 1 arg (14) The problem associated with the usage of film heat transfer coefficient for network are prediction especially as it relates to process retrofit was first identified by Polley et.al., 1990. they argued that there is no systematic means of deriving a single value that is properly representative of a stream that is involved in multiple matching. This renders the film coefficient used for retrofit inaccurate. Secondly, they posited that pressure drop constraints is taken for granted and this could lead to additional cost in terms of extra piping and pumping requirement. They derived equations relating pressure drop with film coefficient for some exchange types. Polley et.al., 1991 employed their methodology, to a very large extent, is still premised on film coeffienct though with a more accurate value. The large extent, is still premised on film coefficient though with a more accurate value. The major flaw of their methodology is the lack of consideration for the necessary change in stream properties with respect to temperature. Perhaps this explains why the state-of–the art procedure is still entirely based on film coefficient. 3. Improved model The frictional pressure drop in a heat exchanger can be related to the exchanger area and film coefficient as follow [Polley et al. 1990]: m KAhP =∆ (15) Where, ∑∑∑ =∆ =      + ∆ = iNS j jiLM i cold jcold hot jhotLMi ii hT Q hhT Q A 1,11 111
  • 4. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 65 =∆P Allowable pressure drop K= Constant solely dependent on physical properties, volumetric flow rate and a single characteristic dimension M= exponential constant dependent on geometry (m=3.5 for tube-side and 5.1 for shell side in a shell and heat exchanger) From equation (13), the contribution of stream j in interval I to the network area can be written as follows;         ∆ = ijiLM i ij hT Q AI ,, , 1 (16) Applying equation (15) to a stream j in interval I yields; m ijijijij hACKP ,,,, =∆ (17) Where, Aj,I =area contribution of stream j in interval I ACj,I =contact or physical area of stream j interval i In order to related the two areas, the following expression has been suggested [Polley et al., 1990]. ∑ ∑=         += N K K K K jj A CP CP AAC 1 (18) Where N is the number of opposing streams. Let us consider again the composite curve of Figure1. Suppose we have two hot stream (1&2) and two cold streams (3&4) in the same interval, the area contributions of each of the streams is given as follows:         ∆ = iiLM i hT Q A ,1, 1 ,1 1 (19)         ∆ = iiLM i hT Q A ,2, 1 ,2 1 (20)         ∆ = iiLM i hT Q A ,3, 1 ,3 1 (21)       ∆ = iiLM i hT Q A 41, 1 ,4 1 (22) The pressure drops of the streams in the interval i are given by M iiii hACKP ,1,1,1,1 =∆ (23) M iiii hACKP ,2,2,2,2 =∆ (24) M iiii hACKP ,3,3,3,3 =∆ (25) M iii hACKP 1,4,4,4,4 =∆ (26) The contact areas of the streams are i ii i i ii i ii A CPCP CP A CPCP CP AAC ,4 ,4,3 ,4 ,3 ,4,3 ,3 ,1,1 + + + += (27) i ii i i ii i ii A CPCP CP A CPCP CP AAC ,4 ,4,3 ,4 ,3 ,4,3 ,3 ,2,2 + + + += (28) i ii i i ii i ii A CPCP CP A CPCP CP AAC ,2 ,2,1 ,2 ,1 ,2,1 ,1 ,3,3 + + + += (29)
  • 5. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 66 i ii i i ii i ii A CPCP CP A CPCP CP AAC ,2 ,2,1 ,2 ,1 ,2,1 ,1 ,4,4 + + + += (30) The total network area for interval i is given by Ai=AI1,i + AI 2,I + AI 3,I + AI 4,I (31) Equations 19-31 give a system of 13 equations in 13 unknowns. The unknowns are four, AIs ,four ACs, four hs and Ai LMT∆ , four CPS, and A, while the known are four given by 4375.3 1 32 k kk K = (32) where, for the tube-side, 3 1 8.0 1 Pr023.0             = µ ρλ i i d d k (33) p ii n dd k             = ρ ρ µ 25.0 2 1582.0 (34) p i Vn d k 4 3 = (35) and for the shell-side; 501 1 32 k kk K = (36) 3 1 55.0 1 Pr36.0             = µ ρλ e e d d k (37)             = − e e d d k ρ µ ρ 19.0 2 895.0 (38) Vd dPP k o ott 23 )(4 Π − = ((39) Thus we obtain a well defined system of non-linear algebraic equations. A similar set of equations can be written for the other intervals of energy recovery. The total network area requirement is then given by, ∑= Intervals iett AA 1 arg (40) This algorithm is pressure based and thus it is consistent with the usual basis for the necessary variations of physical properties that normally arise from changing temperatures. 4. Method of solution In the method of solution, it is assumed that in a network there are NI intervals and NSi streams in a given interval. Note that NSi includes both the hot and cold stream in the interval. Writing the area contribution, pressure drop and contact area equations for the NI intervals will give a system of 3 ∑ , non-linear equations. These equations can be solved by the method of successive substitution. For example, for a particular stream j in an interval I, the algorithm is a follows 1. Guess a value of film heat transfer coefficient (h j.i guess ) 2. Substitute (h j.i guess ) in area contribution equation to calculate Alj.i 3. Evaluate ASCj.i from the contact area equation 4. Use the pressure drop equation to calculate hj.i denoted hj.i cal 5. Compare (h j.i guess ) and hj.i cal
  • 6. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 67 In order to facilitate the solution of the system of equations developed above, certain simplifying assumptions have to be made. The most important one is the difference in the functional relationship between P and h for the tube-side and the shell-side of a shell-and-tube heat exchanger. Certain streams will have to be consigned to the tube-side while others are consigned to the shell-side depending on their properties. Fir grassroots application, this does not present mush difficulty. However, in retrofit the decision has to be made from the current flow pattern. 5. Result and discussion 5.1 Case study I This case study is the example problem of Linnhoff ad Tjoe, 1986 depicted in Figure 2. The minimum temperature difference in the network occurs at the hot end of exchanger 3 and its value is 32o C. Problem table calculations using HERO software indicate a target heating of 14,959.4 kW and cooling of 12,709.4 kW as opposed to the current consumption values of 17,597 kW and 15,510 kW respectively. The pinch occurs at hot stream temperature of i159o C and at cold temperature of 1270 C. pinch modifications are them made to arrive at the synthesised network shown in Figure 3. The state-of-the-art method is first used to estimate area for the original network (targting) and the synthesized network. Then the newly developed methodology is employed to do the same. Detailed design of the network is then done using Kern’s method 9,10 to estimate the realistic network area [Kern, 1984]. The results obtained are shown in Table 1. The old methodology estimated a target area that is 59% higher than the detailed design whole the network synthesis area is 43% higher than the detailed design. On the other hand, the new methodology gives target area that is only 1.52 % higher than the detailed design while the synthesis area is merely 0.3% higher than the detailed design. Table 1: Result for case study I Old Methodology (sq.m) This work (sq.m) Target 3194.6 1003.2 Synthesis 1886.09 991.3 Detailed Design 1309.8 988.0 Figure 2: Base case network for case study 1 1 159 2 2000923017597 267 4 1815 13,695 5 196.1 118 H 93.3 26 20.4 88 228.577 1 C1 C2 5043 4381 2 265 127 CP(kW/K) 3 343 53.8 90 43
  • 7. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 68 Figure 3: Retrofit of case study 1 by inspection 5.2 Case study II The second study is the aromatic plant first presented in the IChemE User’s Guide [Kemp, 2007]. It used in the form presented by Polley etal., 1991. The network is shown in Figure 4. Using a ∆T min of 25o C, they carried out problem table calculations and then modified the network in accordance with pinch procedure. The resulting network is shown in Figure 5. The old procedure for area estimation yield a difference of about 43% between targeting and detailed design and a difference of 50% between network synthesis and detailed design. The new methodology is first employed to estimate target area and the synthesis area. Then the detailed design of the exchangers is carried out using kern method. Table 2 reveals a similar trend to case study I. The target and synthesis areas are 43% and 50% higher the detailed design respectively with the old methodology. The new methodology gives target and synthesis area that are only 1.3 and 1.8% higher than he detailed design area respectively. Table 2: Result for case study II Old Methodology (sq.m) This work (sq.m) Target 12,889 8544.3 Synthesis 14,569 8595 Detailed Design 7318 8443 In both cases, the maximum difference between the target, synthesis and detailed design areas estimated by the new methodology is less than 2%. This runs counter to the old methodology, which gives a difference of as much as 59% between target area and actual design area. There is therefore an excellent agreement between the three stages of process integration arising from the new methodology. 1765 kW2570 kW9230 kW 1 2 3 C 2 C 1 5 1 CP (Kw/k) 2 3 4 4 5 118265 H 11930 kW 1245 kW 5042 kW 4381 kW 159 77 267 88 343 90 26 127 228.5 20.4 53.8 93.3 196.1 15,262 kW
  • 8. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 69 Figure 4: Base case network for case Study II Temp. (C) Duty (kW) Cp (kW/C) H1 H2 H3 H4 E4 E2E1 E6 C3 E3 E5 C2 E7 C1 C1 C2 C3 C4 C5H1 100 160 60 100 400 70 350 60 200 40 160 60 100 45 35 85 60 140 3551 127 75.5 194.2 84.2 25116 107.8 1452 154.2 327 220 220 300 160 164 130 170 300 960022400 6600 1548 20000 2334 5148 18550 108.6141.9 188
  • 9. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 70 6. Conclusions The following conclusions can be drawn from this work 1. The state-of-the-art methodology is grossly inefficient as it predicts area widely different from the actual network area, thereby leading to suboptimal network and unrealistic predictions. 2. The new methodology synchronises the area requirement arising from the three stages of process integration namely targeting, synthesis and detailed design as evident in the excellent agreement between the areas estimated for the three stages. 3. The new methodology does not involve additional cost in terms of extra piping and pump requirement since due cognisance is taken of it right at the targeting stage. 4. The new methodology is perfectly capable of handling process retrofit which had hitherto been an area of application with much difficult and doubts. NOMENCLATURE A Area, m2 Ac Contact area, m2 Amin Minimum area requirement of a network, m2 Atarget Target area for a network, m2 CP Capacity flow rate, W/K de Equivalent of the shell-side, m dI Diameter of inner tube, in E1,E2,E3,E4 Process heat exchangers h Film heat transfer coefficient, W/m2 K HEN Heat Exchanger Network J,K,I Subscripts for the number of streams K Physical property constant M Exponential constant Figure 5: Modified Network for Case Study II Temp. (C) Duty (kW) Cp (kW/C) H1 H2 H3 H4 E4 E2E1 E6 C3 E3 E6 C2 E7 C1 C1 C2 C3 C4 C5H1 100 160 60 100 400 70 350 60 200 40 160 60 100 45 35 85 60 140 3551 127 75.5 194.2 84.2 25116 107.8 1452 154.2 327 220 220 300 160 164 130 170 300 960020515 6600 1427 20000 2334 5148 18550 108.6141.9 197.4
  • 10. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 71 np Number of tube passes NI Number of intervals in a network NS Number of streams P Pressure drop, N/m2 Q Heat load, W ∆ Tlm Logarithmic mean temperature difference, K ∆ Tmin Minimum temperature difference, K U Overall heat transfer coefficient, W/m2 K V Volumetric flow rate of fluid, m3 /s REFERENCES Bakhtiari, B., Bedard, S. 2013. Retrofitting heat exchanger networks using a modified network pinch approach. Applied Thermal Engineering, 51, 973-979. Beninca, M., Trierweiler, J.O., Secchi, A.R. 2011. Heat integration of an olefins plant: pinch analysis and mathematical optimization working together. Brazilian Journal of Chemical Engineering, 28(1), 101-116. Bogataj, M., Kravanja, Z. 2012. An alternative strategy for global optimization of heat exchanger networks. Applied Thermal Engineering, 43, 75-90. Ciric, A.R., Floudas, C.A. 1990. A comprehensive optimization model of the heat exchanger network retrofit problem. Heat Recovery System CHP, 10, 407-422. Douglas, J. M. 1988. Conceptual design of chemical processes, 216-288, Mc Graw Hill, Singapore. El-Halwaji, M. 2006. Process integration. Elsevier, London Escobar, M., Trierweiler, J.O. 2013. Optimal heat exchanger network synthesis: A case study comparison. Applied Thermal Engineering, 51, 801-826. Feng, X., Pu, J., Yang, J., Chu, K.H. 2011. Energy recovery in petrochemical complexes through heat integration retrofit analysis. Applied Energy, 88, 1965-1982. Fieg, G., Luo, X., Jezowski, J. 2009. A monogenetic algorithm for optimal design of large-scale heat exchanger networks. Chemical Engineering and Processing, 48, 1506-1516. Jezowski, J.M., Shethna, H.K., Castillo, F.J.L. 2003. Area target for heat exchanger networks using linear programming. Industrial and Engineering Chemistry Research, 42, 1723-1730. Jiang, N., Bao, S., Gao, Z. 2011. Heat exchanger network integration using diverse pinch point and mathematical programming. Chemical Engineering and Technology, 34(6), 985-990. Kemp, I.C. 2007. Pinch analysis and process integration: A user guide on process integration for the efficient use of energy. Elsevier, London. Kern, D.Q. 1984. Process heat transfer, McGraw H ill, Singapore. Lam, H.L., Klemes, J.J., Kravanja, Z., Varbanov, P.S. 2011. Software tools overview: process integration, modeling and optimization for energy saving and pollution reduction. Asia-Pacific Journal of Chemical Engineering, 6, 696-712. Laukkanen, T., Tveit, T.M., Ojalehto, V., Miettinen, K., Fogelholm, C.J. 2012. Bilevel heat exchanger network synthesis with an interactive multi-objective optimization method. Applied Thermal Engineering, 48, 301-316. Li, B.H., Chang, C.T. 2010. Retrofitting heat exchanger networks based on simple pinch analysis. Industrial and Engineering Chemistry Research, 49, 3967-3971. Linnhoff, B,and Tjoe, T.N. 1986. Using pinch technology for process retrofit. Chemical Engineering, 93(8),47- 60. Luo, X., Xia, C., Sun, L. 2013. Margin desin, online optimization, and control approach of a heat exchanger network with bypasses. Computers and Chemical Engineering, 53, 102-121. Nejad, S.H.A., Shahraki, F., Birjandi, M.R.S., Kovac Kralj, A., F. Fazlollahi, 2012. Modification of heat exchanger network design by considering physical properties variation. Chemical and Biochemical Quarterly, 26(2), 79-87. Nguyen, D.Q., Barbaro, A., Vipanurat, N., Bagajewicz, M.J. 2010. All-at-once and stp-wise detailed retrofit of heat exchanger networks using an MILP model. Industrial and Engineering Chemistry Research, 49, 6080-6103. Polley, G. T., Shahi Panjeh, M. H. 1991. Interfacing heat exchanger Network Synthesis and detailed heat exchangers design, IchemE, 69, A6. Polley, G.T. Shahi panjeh, M. H. and Jegede, F. O. 1990. Pressure drop considerations in the retrofit of heat exchanger networks. IchemE, 68, part A, 2H-220. Ponce-Ortega, J.M., Jimenez-Gutierrez, A., |Grossmann, I.E. 2008. Optimal synthesis of heat exchanger networks involving isothermal streams. Computers and Chemical Engineering, 32(8), 1918-1942. Ponce-Ortega, J.M., Serna-Gonzalez, M., Jimenez-Gutierrez, A. 2010. Synthesis of heat exchanger networks with optimal placement of multiple utilities. Industrial and Engineering Chemistry Research, 49, 2849-2856.
  • 11. Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.3, No.6, 2013 72 Promvitak, P., Siemanond, K, Bunluesriruang, S., Raghareutai, V. 2009. Retrofit design of heat exchanger networks of crude distillation unit. Chemical Engineering Transactions, 18, 99-104. Rezaei, E., Shafiei, S. 2009. Heat exchanger networks retrofit by coupling genetic algorithm with NLP and ILP methods. Computers and Chemical Engineering, 33, 1451-1459. Serna, M., Jimenez, A. 2004. An area targeting algorithm for the synthesis of heat exchanger networks. Chemical Engineering Science, 59, 2517-2520. Shethna, H.K., Jezowski, J.M., Castillo, F.J.L. 2000. A new methodology for simultaneous optimization of capital and operating cost targets in heat exchanger network design. Applied Thermal Engineering, 20, 1577- 1587. Smith, R. 2005. Chemical process design and integration, John Wiley & Sons, England. Sun, K.N., Wan Alwi, S.R., Manan Z. A. 2013. Heat exchanger network cost optimization considering multiple utilities and different types of heat exchangers. Computers and Chemical Engineering, 49, 194-204. Townsend, D. W. and Linnhoff, B. 1984. Surface area targets for heat exchanger networks, paper presented at the Institution of Chemical Engineers Annual research Meeting, Bath, U.K. Wan Alwi, S.R., Manan, Z.A. 2010. A new graphical tool for simultaneous targeting and design of a heat exchanger network. Chemical Engineering Journal, 162, 106-121. Zhang, H., Rangaiah, G.P. 2013. One-step approach for heat exchanger network retrofitting using integrated differential evolution. Computers and Chemical Engineering, 50, 92-104. Zhu, X.X., O’Neill, B.K., Roach, J.R., Wood, R.M. 1995a. A new method for heat exchanger network synthesis using area targeting procedures. Computers and Chemical Engineering, 19(2), 197-222. Zhu, X.X., O’Neill, B.K., Roach, J.R., Wood, R.M. 1995b. Area targeting methods for the direct synthesis of heat exchanger networks with unequal film coefficients. Computers and Chemical Engineering, 19(2), 223-239.
  • 12. This academic article was published by The International Institute for Science, Technology and Education (IISTE). The IISTE is a pioneer in the Open Access Publishing service based in the U.S. and Europe. The aim of the institute is Accelerating Global Knowledge Sharing. More information about the publisher can be found in the IISTE’s homepage: http://www.iiste.org CALL FOR PAPERS The IISTE is currently hosting more than 30 peer-reviewed academic journals and collaborating with academic institutions around the world. There’s no deadline for submission. Prospective authors of IISTE journals can find the submission instruction on the following page: http://www.iiste.org/Journals/ The IISTE editorial team promises to the review and publish all the qualified submissions in a fast manner. All the journals articles are available online to the readers all over the world without financial, legal, or technical barriers other than those inseparable from gaining access to the internet itself. Printed version of the journals is also available upon request of readers and authors. IISTE Knowledge Sharing Partners EBSCO, Index Copernicus, Ulrich's Periodicals Directory, JournalTOCS, PKP Open Archives Harvester, Bielefeld Academic Search Engine, Elektronische Zeitschriftenbibliothek EZB, Open J-Gate, OCLC WorldCat, Universe Digtial Library , NewJour, Google Scholar