过程优化设计热集成4-1

平衡组合曲线
Each utility pinch creates an additional design region within which only the appropriate utility is used.
Summary
• The grand composite curve can be constructed directly form the problem table algorithm.
门槛问题的设计
门槛问题的设计
Example
∆H 452.20 428.18 505.56
320.00 528.00 413.00 340.60
Example
门槛问题的设计
门槛问题的设计
Whether or not they remain Threshold Problems, usually depends on the economy of scale
过程装备优化设计
4 合理利用公用工程
Multiple Utilities
(1)由问题表格法绘制总组合曲线
(2) 蒸汽
低压蒸汽(P≤2.5MPa，T≤400℃） 中压蒸汽(2.5MPa＜P≤6MPa， 400℃＜T≤450℃) 高压蒸汽(6MPa＜P≤14MPa， 460℃＜T≤540℃) 超高压蒸汽(14MPa＜P≤17MPa， 540℃＜T≤570℃) 亚临界压力蒸汽(P17～18MPa， 540℃＜T≤570℃) 超临界压力蒸汽(P>18MPa, T>570℃)
40
36
1 180℃ 2 130℃
100℃
120℃
2000 80℃
2520
67℃
680
H 91.5℃
160
H
116℃
60℃ 3
60℃
1080
CP 20
40℃ 40
80
30℃ 4 36
门槛问题的设计
Summary
• Some problems exhibit a threshold-only hot or cold utility required.
• True threshold problems have large temperature driving forces and no pinch.
(2) 蒸汽
(2) 蒸汽
(2) 蒸汽
TTFT
TPinch Tacid dew To
(3) 烟气
To TPinch
QHmin
TTFT
H TTFT = theoretical flam temperature Tacid dew= acid dew point To = ambient
Pinch temperature might be limiting stack temperature.
(after utility selection)
5 门槛问题
Threshold Problems
5. 门槛问题
5. 门槛问题
5. 门槛问题
ຫໍສະໝຸດ Baidu
5. 门槛问题
门槛问题与夹点问题
门槛问题——过程系统只需要一种公用工程物流。
门槛问题和夹点问题
Design for Threshold Problems
• Grand composite curve shows utility requirements in enthalpy and temperature terms.
• Temperature differences built into the construction • Best tool for utility placement. • Balanced composite curves give the true picture
• Most threshold problems turn out to be pinched problems after multiple utilities used.
Working Session
Threshold Problems
176.5 126.5 123.5 103.5 76.5 63.5 36.5 33.5
4.4 公用工程夹点
4.4 公用工程夹点
4.4 公用工程夹点
The composite curves give the true picture
⇨ We need to add the utilities back in ⇨ Form Balanced Composite Curves
平衡组合曲线
(3) 烟气
(4) 制冷剂
四氟乙烷(R134a)：-26.3℃ 氟利昂-12(R12，CF2Cl2)：-29.8℃ 氨(R717)：-33.3℃ 氟利昂-22(R22，CHF2Cl)：-41℃ 丙烷(R290)：-42℃ 二氧化碳(R744)：-78.5℃ 乙烯(R1150)：-103.9℃ 甲烷(R50)：-161.5℃ 液氮：-196.6℃
Hinterval=-1000 Hinterval=-180 Hinterval=-480 Hinterval=1512 Hinterval=988 Hinterval=-108 Hinterval=108
840 1840 2020 2500 988
0 108
0
CPH<CPC
40
80
20
36
CPH>CPC