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Pinch Technology: 기본 이론. Identify Opportunities by Inspection. Stream A. Stream B. 10 C. Process Unit. 150 C. Feed. Product. 100 C. 30 C. Steam. Cooling Water. An opportunity for heat recovery. B. A. Good Idea … or is it?. 150 C. Process Unit. 10 C. Feed. Product. 100 C. - PowerPoint PPT Presentation
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Pinch Technology:
기본 이론
Identify Opportunities by Inspection
ProcessUnit
10 C
100 C
150 C
30 C
Steam Cooling Water
Feed Product
An opportunity for heat recovery
Stream A Stream B
Heat kW
ProcessUnit
10 C
100 C
150 C
30 C
Steam Cooling Water
Feed Product
Tem
pera
ture
C
Good Idea … or is it?
A
B
Tem
pera
ture
C
Heat kW
CoolingWater
Steam
A pity !A pity !
One part of the siteOne part of the site Another locationAnother location
ProcessUnit
10 C
100 C
150 C
30 C
Steam Cooling Water
Feed Product
Tem
pera
ture
C
Heat kW
Not a good idea any more?Not a good idea any more?
A good idea ?A good idea ?
C
D
B
A
Tem
pera
ture
C
But suppose we could have seen the entire picture !But suppose we could have seen the entire picture !
Better Approach
B
A
C
D
Especially
• On a large site• When we have different departments• No one person has all the knowledge• etc.
How can we avoid missing such opportunities?
Do we really need 2,040 kW of steam?
An Example
Heating and Cooling Duties
The hot composite curve
The cold composite curve
Energy Targets Ahead of Design!
The composite curves
PINCH
Qcmin=120 kW
QHmin=960kW
The composite curves show our target (minimum)
should be 960 kW of steam
We actually use 2040 kW
Why?
The closest approach between the compositecurves represents the "Pinch".
Divide the process at the Pinch
The feasibility of heat transfer
Therefore if we have ‘A’ kW of cross pinch heat transfer our utility consumption will be: Steam Q HMIN + A
Cooling Water QCMIN + A
In our example the X pinch heat transfer must be 1080kW
• Do not use hot utility below
• Do not recover process heat across
• Do not use cold utility above
Do not Transfer heat across the PinchDo not Transfer heat across the Pinch
Divide the process at the pinch
Pinch Design Principles
Design now achieves the target of 960 kW steam
Pinch Design
NEW
Design now achieves the target of 960 kW steam
Pinch Design
NEW
SMALLER EXCHANGERAND BOILER PLANT
SMALLEREXCHANGERAND COOLINGTOWER
NEW
SMALLER EXCHANGERAND BOILER PLANT
SMALLEREXCHANGERAND COOLINGTOWER
Which Design Is Cheaper?
To operate - clearly the one with less energyTo build?
The more energy efficient design is not necessarily more expensive
Original Design
Q Q HOTHOT
Q Q HOTHOT
TT
HH
Q Q COLDCOLD
TT
HHQ Q COLDCOLD
Composite Curve Grand Composite Curve
Process / Utility Interface
TT
HH HH
HP SteamHP Steam
Cooling WaterCooling Water
HP SteamHP Steam
MPMP
LPLP
bfwbfwCWCW
Simple Process/UtilityInterface
Alternative Process/UtilityInterface
Process / Utility Interface