Page 114 - Sustainability in the Process Industry Integration and Optimization

P r o c e s s I n t e g r a t i o n f o r I m p r ov i n g E n e r g y E f f i c i e n c y 91

(a)
Rules: CP ≥ CP ; N ≥ N C PINCH CP
H
H
C
[kW/°C]
30°C 100°C
1
5
40°C 100°C 4
2
? ?
15°C 90°C
3 7
CP rules are not satisfied

(b)
≥ CP ; N ≥ N PINCH
Rules: CP H C H C CP
[kW/°C]
30°C 100°C
1 5

40°C 100°C
2 4

15°C 90°C
3 4

3
Split the cold Stream

FIGURE 4.59 Splitting to enable CP values for essential matches.

PINCH CP
[kW/°C]
30°C 100°C
C1 1 1 5
T =100−300/5=40°C
1
T =100−225/4
2
40°C T 2 =43.75°C 100°C
C2 2 2 4
15°C 90°C
3 4
3

= 4 × (90−15)=300 kW Q =3 × (9−15)=225 kW
Q 1 2
FIGURE 4.60 Splitting and trivial tick-off.