Page 302 - Design and Operation of Heat Exchangers and their Networks

288 Design and operation of heat exchangers and their networks

Example H3C4
This example was originally used by Colberg and Morari (1990). The unit
costs and utility costs were supplemented by Yee and Grossmann (1990) and
Xiao et al. (2006), respectively (see Table 6.23). The best network without
stream split was found by Wang et al. (2017), of which TAC¼79,233$/yr.
Using the hybrid genetic algorithm based on the stagewise superstructure
(Luo et al., 2009), we find the better solution shown in Fig. 6.23.The
network consists of two subnetworks {H1, H2, C1, C2} and {H3, C3,
C4}. Each subnetwork has an independent variable. The local
optimization yields TAC¼176,200$/yr.

Table 6.23 Problem data for H3C4 (Xiao et al., 2006).
2
_
Stream T in (K) T out (K) C (kW/K) α (kW/m K) Cost ($/kWyr)
H1 626 586 9.802 1.25
H2 620 519 2.931 0.05
H3 528 353 6.161 3.2
C1 497 613 7.179 0.65
C2 389 576 0.641 0.25
C3 326 386 7.627 0.33
C4 313 566 1.69 3.2
HU 650 650 3.5 130
CU 293 308 3.5 20
2
Heat exchanger cost¼8600+670A 0.83 $/yr (A in m )
Total annual cost ($/yr)
Solutions in the literature Reported Revised
Own work – 176,200
Wang et al. (2017) a 183,029 183,029
Xiao et al. (2006) for multistream HE – 183,332
Yee and Grossmann (1990) – 185,106
Isafiade and Fraser (2008) 168,700 188,002
a
No stream split.