Aspentech - Power Plant Optimization
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Transcript of Aspentech - Power Plant Optimization
©2000 AspenTech. All Rights Reserved.
Power Plant Optimization
2©2000 AspenTech. All Rights Reserved.
Why Focus On Energy / Utilities?
• Energy is the single largest operating expense after raw materials in the process industries
• “The best spend less than 50% on total energy cost compared to the worst.” (Solomon)
• Deregulation has opened up new opportunities / threats
• Linked to CO2 / NOX / SOX
• Energy costs are rising in some regions
3©2000 AspenTech. All Rights Reserved.
Energy Optimization Goals
• Minimize Operating Costs / Maximize Profit while:– Meeting electrical, steam, hydrogen and offgas
demands– Honoring operating/equipment constraints– Honoring contract constraints– Environmental concerns (NOx, CO, etc.)
4©2000 AspenTech. All Rights Reserved.
Site Wide Energy SystemPower Import/Export
ProcessA
ProcessB
ProcessC
ProcessD
Fuel
ProductSide-ProductFeed
ProductFeedSide-Product
Energy System
WaterSystem
GasSysteme.g.H2
Production System
Fuel Import/Export Water
WasteWater
Emissions (CO2, SOx, NOx)
• Combined production and energy system analysis is required• Interactions between energy - water and off-gas system considered• Constraints from out of site bound should be considered
5©2000 AspenTech. All Rights Reserved.
Utility System Operation Challenges
Which boilers should I use and at what load should I run these boilers?Which boilers should I use and at what load should I run these boilers?
Is it economic to run my steam turbine generator?Is it economic to run my steam turbine generator?
What drives should I use for the BFW pump?
What drives should I use for the BFW pump?
At what load should I run the GTG?At what load should I run the GTG?
What is the lowestoperating cost?
What is the lowestoperating cost?
What fuels should I use and how much should I purchase –what contract?
What fuels should I use and how much should I purchase –what contract?
How much electricity should I purchase, how much could I sell and at what price?
How much electricity should I purchase, how much could I sell and at what price?
How much steam do I need to provide today, tomorrow, next week? How does Actual compare to Plan?
How much steam do I need to provide today, tomorrow, next week? How does Actual compare to Plan?
How is my equipment performing? When should I shut down for maintenance?
How is my equipment performing? When should I shut down for maintenance?
• Many decisions to be made under many constraints• How can we consider all aspects simultaneously?• Many decisions to be made under many constraints• How can we consider all aspects simultaneously?
6©2000 AspenTech. All Rights Reserved.
Optimization Pyramid
OpenOpen--LoopLoopAdvisoryAdvisory
SystemSystem
ClosedClosed--Loop OptimizationLoop Optimization
Multivariable ControlMultivariable Control
Control & AutomationControl & Automation
InstrumentationInstrumentation
OpenOpen--LoopLoopAdvisoryAdvisory
SystemSystem
ClosedClosed--Loop OptimizationLoop Optimization
Multivariable ControlMultivariable Control
Control & AutomationControl & Automation
InstrumentationInstrumentation
7©2000 AspenTech. All Rights Reserved.
Life Cycle Energy Management
8©2000 AspenTech. All Rights Reserved.
Lessons Learned
• Find the benefits1. What is 1% of your energy bill?2. What is your complexity and flexibility?3. Can you estimate the performance of the equipment?
• Get the benefits1. One time effort is not enough2. You must deal with whatever pushes away from the optimum3. Measurements are important4. Automation is the key to continued benefits
9©2000 AspenTech. All Rights Reserved.
Aspen Utilities Solution Overview
Tariffs
Operational Constraints
Plant Demands
Closed Loop Optimization• Load distribution• Multiple objective functionsO
PER
ATI
ON
S TO
OL
Tariffscenarios
Seasonalvariations
Changes in demande.g. site expansion
What-if Analysis• Turbine/ boiler on/off decisions • Tariff selection• Optimize Investment options• Significant changes in demands• Changes in fuel supply
STRA
TEGIC
TOO
L
DCS
Multi-variable Predictive Control
On-line Open Loop Decision
Making
On-line Open Loop Decision
Making
Lowest Cost Scheme
Lowest Cost Scheme
On-line Closed Loop OptimizationOn-line Closed
Loop Optimization
Lowest Cost Operation
Lowest Cost Operation
10©2000 AspenTech. All Rights Reserved.
Strategic Solution - Advisory
• Solution Integrated/Consistent with Operation Solution
• Long-term Issues– Contract Selection/Negotiation– Capital Investment
• Short-medium term issues– Equipment selection optimization (on/off decisions)– Maintenance– Performance monitoring
• Optimization– MILP solver with multi-period optimization capability - can include
process production planning– Off-line decision making / On-line decision support
11©2000 AspenTech. All Rights Reserved.
Demand Forecast
Considering steam demand profile behavior into optimization
Time
Steam DemandT/hr
0 hours 48 hours
Do not start a new turbineSwitch turbine 2 on
12©2000 AspenTech. All Rights Reserved.
Contract Optimization
Time
Gas DemandM3/hr
Jan April Oct DecJuly
8000 hr Average(determined at end of year)
Peak Load
demands subject to incidental gas price (planned upfront)
Middle Load
Base Load
HUG contract value(planned up front)
Electricityuse
230
25 gld/kWh
2.5 gld/kWh[MWe]
225
180
Chronological year
Peak load
Middle loadTransport boundary
Base load
Gas Contract Structure
Elect. Contract Structure
Electricity Contract
0
20
40
60
80
100
1200:00
1:00
2:00
3:00
4:00
5:00
6:00
7:00
8:00
9:00
10:00
11:0012:00
13:00
14:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Jan. - Mar.Apr.-Jun.SepJul.-Aug.Oct-Dec.
13©2000 AspenTech. All Rights Reserved.
Contract optimization
Jan
GasM3/hr
Jan DecOne profile for each header Consumer gas & electricity requirement
SteamT/hr
Dec
Elect.MWe
Jan Dec
Iterations(new tariff constants)
N-1 and equipment operational constraints
Alternative fuel availability
Gas & elect.bill for selected contract
GasM3/hr
Jan Dec
ElectMWe
Jan Dec
Past ProfileOptimized Profile
Site wide gas and electricity demands
Utilities Optimizer
14©2000 AspenTech. All Rights Reserved.
Operations Solution – Closed Loop
• Tightly Integrated Package– Advanced Process Control - DMCplus– Real Time Optimization –AspenPlus Optimizer– Proven Reliability
• Integrated Goals– Tie line control– Constraint handling– Boiler, turbine load allocation– Performance Monitoring
15©2000 AspenTech. All Rights Reserved.
Operations – Closed Loop
• AspenPlus Optimizer calculates optimal operation for current state of process utilizing a rigorous model of process– Buy/Sell (within constraints) – Turbine/boiler loading
• DMCplus implements optimization targets and handles constraints and changes in demands and process between optimization solutions
16©2000 AspenTech. All Rights Reserved.
When Do You Need RTO ?
• High degree of non-linearity.– Can be fundamentally modeled.
• Frequent disturbances.– Correct time scale.– Changing economics and plant constraints.
• Significant degrees of freedom with substantial benefits.– Sufficient application scope.
17©2000 AspenTech. All Rights Reserved.
AspenPlus Optimizer
• Closed Loop Real Time Optimization
• Based on fundamental non-linear models
• Frequent optimization cycles – Model calibrated to plant each run (parameters updated)– Uses current economics and constraints– Cycle times of ~5 minutes
• Handles complex Constraints
• Handles tier pricing
• Consistency with APC and Strategic Model
• Facilitates performance monitoring
18©2000 AspenTech. All Rights Reserved.
Closed Loop Optimization Sequence
Full Plant Measurements
LINE-OUT PERIOD
WAITPLANT STEADY?
MEASUREMENTVALIDATION
PARAMETERCALCULATIONS
OPTIMIZATIONCALCULATIONS
IMPLEMENT OPT.SETPOINTS
NO
NO
Selected PlantMeasurements
Selected PlantMeasurements &Controller Limits
PLANT STEADY?
1 MINUTE
1 MINUTE
Controller Limits
Control and Opt. Status Info
Prices
19©2000 AspenTech. All Rights Reserved.
Closed Loop Optimization Benefits
Time (Minutes)
Uni
tPro
fitab
ilify
($) major disturbance/ price change
actual unit profit
potential unit profit
RTO Implementations
20©2000 AspenTech. All Rights Reserved.
0
0.005
0.01
0.015
0.02
0.025
1999/7/1
1999/7/15
1999/7/29
1999/8/12
1999/8/26
1999/9/9
1999/9/23
1999/10/7
1999/10/21
1999/11/4
1999/11/18
1999/12/2
1999/12/16
1999/12/30
2000/1/13
2000/1/27
2000/2/10
2000/2/24
2000/3/9
2000/3/23
Foul
ing
Fact
or [m
2hC
/kca
l]
250
270
290
310
330
350
370
390
410
Out
let T
emp.
of E
xhas
t Gas
[C]
ボイラー汚れ係数1 m 2hC /kcal ボイラー汚れ係数2 m 2hC /kcal ボイラー汚れ係数3 m 2hC /kcal ボイラー排ガス温度 C
Temp. of Exhaust Gas
Fouling of 1st Super heater
Fouling of 2nd /3rd Super heater
Outage of Plant
-Strong correlations between Boiler Fouling and Outlet Temp. of Exhaust Gas
- Assumed the fouling was removed by Thermal shock at the outage of Plant
Analysis & Management of Boiler Fouling
Fouling in Economizer
21©2000 AspenTech. All Rights Reserved.
DMCplus
• Dynamic multivariable control– Moves multiple variables simultaneously – Controls multiple variables simultaneously
• Operates at a scheduled high frequency– Typically 15 sec. in utilities plant
• Reduces variability in key variables
• Honors constraints
• Automatically handles reconfiguration of equipment and control system
22©2000 AspenTech. All Rights Reserved.
Benefits of DMCplus
APCEconomic Optimum
Operating Region
Equipment Constraints
Temperatures
Steam Demands
Power DemandReserve Requirements
Condensate Supply
Operator'sPreferredOperating
Region
23©2000 AspenTech. All Rights Reserved.
64
66
68
70
72
74
76
0 240 480 720 960time [min.]
220
240
260
280???
? ???
Power Generation
Control Start
Exhaust Steam FlowrateUpper Limits
Pow
er G
ener
atio
n [M
WH
/H]
Exha
ust S
team
Flo
wra
te[T
/H]
24©2000 AspenTech. All Rights Reserved.
Aspen Utilities Growing Customer Base
WorkshopWorkshop Implementation
DSM, DSM, Geleen Geleen (Netherlands)(Netherlands)
1998
Titan, MalaysiaTitan, Malaysia1999
Huntsman, TexasHuntsman, Texas
BP Chemicals, HullBP Chemicals, Hull
CepsaCepsa, Spain, Spain
JSR, JapanJSR, Japan
BP BP Bulwer Bulwer Island, Island, AustraliaAustralia
2000
CelaneseCelanese((66 sitessites -- WWWW))
Irving Oil, Irving Oil, NewfoundlandNewfoundland
Samsung, KoreaSamsung, Korea
2001BP Texas CityBP Texas City
GE PlasticsGE Plastics((55 sitessites -- WWWW))
EniPowerEniPower((22 sites sites -- ItalyItaly ))
BP Chemicals BP Chemicals BelgiumBelgium
Sasol, Sasol, SasolburgSasolburg
2002
25©2000 AspenTech. All Rights Reserved.
Utilities Management & Optimization• Benefits
− Significant benefits possible− 1.5-5% reduction in site-wide energy bill
− Provides a consistent approach for all the utilities related management and operations issues− Consistent decision making from contracts to operation
• AspenTech Approach− Systematic project approach - Energy Workshop
Complete Solution
Software Technology Transfer
Project Services+ + =
26©2000 AspenTech. All Rights Reserved.
Optimization Pyramid
OpenOpen--LoopLoopAdvisoryAdvisory
SystemSystem
ClosedClosed--Loop OptimizationLoop Optimization
Multivariable ControlMultivariable Control
Control & AutomationControl & Automation
InstrumentationInstrumentation
OpenOpen--LoopLoopAdvisoryAdvisory
SystemSystem
ClosedClosed--Loop OptimizationLoop Optimization
Multivariable ControlMultivariable Control
Control & AutomationControl & Automation
InstrumentationInstrumentation
27©2000 AspenTech. All Rights Reserved.
CONTROL
STRATEGIC DECISIONS
CLOSED-LOOP OPTIMIZATION
To be successful you need to do all aspects well !!
28©2000 AspenTech. All Rights Reserved.
Clients Include:
Most Major Chemical CompaniesMost Major Olefins ProducersMore than 1,000 successful projectsMore than 300 full plant onlineoptimization applications
Business Breakdown
Olefins32.5 %
Refining48.6 %Polymers
Air SeparationSpecialty ChemPower
Other 18.9 %
Most Major Oil Companies
AspenTech is the World Leader in APC & Optimization
PROVEN integration with all leading DCS platforms including:
Yokogawa, Bailey, Foxboro, ABB, Honeywell, Fisher-Rosemount
Thank You