Page 295 - Design and Operation of Heat Exchangers and their Networks

Optimal design of heat exchanger networks 281

Example H2C2_443KZ
This example is a variant of Example H2C2_443K with different cost
parameters used by Zamora and Grossmann (1998). The problem data
are given in Table 6.17. Toffolo (2009) developed a two-level
optimization algorithm, in which the network configuration is generated
with an evolutionary algorithm by applying genetic operators to a graph-
based representation of the network. With this method, they found the
best network differing from the stagewise superstructure, as is shown in
Fig. 6.17. The network contains two splits and has three independent
variables, and its TAC is 82,363$/yr.
Table 6.17 Problem data for H2C2_443KZ (Zamora and Grossmann, 1998).
_
2
Stream T in (K) T out (K) C (kW/K) α (kW/m K) Cost ($/kWyr)
H1 443 333 30 1.6
H2 423 303 15 1.6
C1 293 408 20 1.6
C2 353 413 40 1.6
HU 450 450 4.8 80
CU 293 313 1.6 20
2
Heat exchanger cost (except heaters)¼6250+83.26A$/yr (A in m )
2
Heat exchanger cost for heaters¼6250+99.91A$/yr (A in m )
Total annual cost ($/yr)
Solutions in the literature Reported Revised
Toffolo (2009) 82,363 82,363
Pariyani et al. (2006, Fig. 2(b)) 85,307 83,937
Pettersson (2008) 84,066
Yerramsetty and Murty (2008) 84,222
Zamora and Grossmann (1998) a 85,968 85,970
a
Adjiman et al. (2000) 74,711
Pariyani et al. (2006, Fig. 2(a)) a 85,972
Gorji-Bandpy et al. (2011) 67,174 Infeasible
a
No stream split.
270.1 041 2400 629.9 400
443 (27.59909) 293
H1
(30)
423 353
H2
(15)
408 333
C1
(20)
413 (17.23082) 303 C2
1400 (40)
Fig. 6.17 OptimalsolutionforExampleH2C2_443KZ(Toffolo,2009),TAC¼82,363$/yr.