Page 293 - Design and Operation of Heat Exchangers and their Networks

Optimal design of heat exchanger networks 279

Example H2C2_320F
This example is 4SP1 problem taken from Lee et al. (1970). Papoulias and
Grossmann (1983a) and Bagajewicz et al. (1998) transferred the problem
data from English units to international system of units (SI). For the
unique revision and comparison of the local minimal TAC, we would like
to take the problem data in its original English units, which were explicit
given by Yerramsetty and Murty (2008) and are listed in Table 6.15.The
best network configuration was found by Azeez et al. (2012).After
optimizing the two independent variables, the TAC of this network
approaches to the minimum of 10,582$/yr, as is shown in Fig. 6.15.
Table 6.15 Problem data for H2C2_320F (Yerramsetty and Murty, 2008).
2
_
Stream T in (°F) T out (°F) C (kBtu/h°F) α (kBtu/ft °F) Cost ($/kBtuyr)
H1 320 200 16.6668 0.3
H2 480 280 20 0.3
C1 140 320 14.4501 0.3
C2 240 500 11.53 0.3
HU 540 540 0.6 12.76
CU 100 180 0.3 5.24
0.6 2
Heat exchanger cost¼35A $/yr (A in ft )
Total annual cost ($/yr)

Solutions in the literature Reported Revised
Azeez et al. (2012) 10,786 10,582
Nishida et al. (1977) a 13,590 10,587
Papoulias and Grossmann (1983a) a,b –
Bagajewicz et al. (1998) a,b 10,580
Yerramsetty and Murty (2008) a 10,782 10,615
Azeez et al. (2013) 10,794 10,631
Pho and Lapidus (1973) a 13,685 13,670
a
Lee et al. (1970) 13,481
a
No stream split.
b
Using SI units.
1353.4
320 (11.77133) 200
H1
(16.6668)
2752. 428
480 280
H2
(20) 646.6
320 140
C1
(14.4501)
245.4 1247.6
500 240
C2
(11.53)
Fig. 6.15 Optimal solution for Example H2C2_320F (Azeez et al., 2012),
TAC¼10,582$/yr.