Real-time Optimization at US Chemical Utilities Plant ... · Chemical Utilities Plant Reduces...
Transcript of Real-time Optimization at US Chemical Utilities Plant ... · Chemical Utilities Plant Reduces...
Real-time Optimization at US Chemical Utilities Plant Reduces Operating Costs
Fabian Robin
Marcelo Carugo
[File Name or Event]Emerson Confidential27-Jun-01, Slide 2
IntroductionIntroduction
• The Chemical Complex
• The Utilities Plant
• The Challenge
– The Need for an Optimizer
– The Solution
• The AMS Optimizer Application
• Project Execution & Benefits Audit
• Business Results
• Summary
• Questions/Comments
[File Name or Event]Emerson Confidential27-Jun-01, Slide 3
The Chemical Complex The Chemical Complex
• There are 15 manufacturing units located within six manufacturing groups
• The site produces a wide range of industrial chemicals that are used as catalysts and intermediates for the manufacture of hundreds of everyday consumer items
• Some chemicals manufactured are used by neighboring industrial plants to make their own products
• They also purchases some chemicals from neighboring plants for use on site.
[File Name or Event]Emerson Confidential27-Jun-01, Slide 4
The Utilities PlantThe Utilities Plant
• The utilities department is responsible for supplying all steam and power requirements on the site and managing the associated contracts.
• Utilities manage the contracts for natural gas supply, steam purchase & power purchase/sale.
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The Utilities PlantThe Utilities Plant
• Key equipment:
– 2 Cogen units (one with supplemental firing)
– 4 fired boilers
– 1 steam turbine generator with steam extraction
– 3 steam headers at different pressures
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Real-Time Optimizer - Project LifecycleReal-Time Optimizer - Project Lifecycle• Project Initiation & Justification
• Project Implementation
– Offline Model Build
– Offline Optimizer
– Online Open-Loop Optimizer
– Online Closed-Loop Optimizer
Benefits evaluated before moving to the next stage of the project
PLANT
OPTIMIZER
Off-Line
PLANT
OPTIMIZER
Open-Loop
PLANT
OPTIMIZER
Closed-Loop
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The Utilities PlantThe Utilities Plant
• Operational Complexities
– The boilers are capable of firing a variety of fuel types including natural gas and one or more auxiliary fuels generated on the site
– Operating ranges for each equipment changes when it is firing a different mix of fuels
– The site is contracted to purchase a minimum amount of steam from a neighboring plant & the minimum amount will vary depending on the supplier’s operating conditions
– Gas turbines employ evaporative cooling & wet gas compression as peak power-demand shaving strategy
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The ChallengeThe Challenge
• The Need for an Optimizer
– Complex plant and continuously changing demands
– Opportunity to find the optimum balance between steam generated and purchased
– Ever increasing cost of fuel and power
– Tool is required to enable sustained beneficial economic decisions on plant operation in real-time
• The Solution
– AMS™ Suite: Real-Time Optimizer selected to generate online, real-time recommendations to the plant operators on the most economical operation of the plant
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The AMS Optimizer ApplicationThe AMS Optimizer Application
• The Process Models– Includes models of all key process operating equipment
– Models of each unit include all parameters that affect the actual operation of the unit (e.g. effect of ambient condition on gas turbine base load)
– Actual process measurements are used to fit the performance curves for each equipment so that model reflects the actual behavior of each unit thus accounting for any deviation from design
– Boiler and Gas Turbine models include the mixed fuel burning capabilities of the actual units.
– Contracts are modeled for all cost and revenue items:
• Natural Gas Purchase
• Steam Purchase
• Electricity purchase/sale
[File Name or Event]Emerson Confidential27-Jun-01, Slide 10
The AMS Optimizer ApplicationThe AMS Optimizer Application
• Optimizer Objective– For the current total steam and power demand:
• Minimize the total operating cost
• Maximize auxiliary fuel burning (when available)
– By
• Choosing optimal Boiler Steam generation (& import) rates
• Choosing optimal Steam Turbine power generation rate
• Choosing optimal Gas turbine power generation rate
– Taking into account, all economic considerations which come to bear on the plant operation including:
• Fuel (natural gas) price (auxiliary fuels are supplied to utilities at no additional cost to Company)
• Loss due to steam venting
• Steam purchase price
• Power purchase price
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The AMS Optimizer ApplicationThe AMS Optimizer Application
• Supplied application consists of:
– Online Optimization System
– Offline Optimization Tool
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The AMS Optimizer ApplicationThe AMS Optimizer Application
• Online optimization system– Open-loop implementation
– Optimizer runs automatically every 5 minutes using live process data
– Results are displayed in Aspen Process Explorer screen for implementation by the operators
– Optimizer manipulates defined operating handles in the process model
– Equipment model performance is automatically tuned online to ensure that model behavior is always consistent with the actual unit operation
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The AMS Optimizer ApplicationThe AMS Optimizer Application
• Offline optimization tool
– Based on the same core models as the online optimization system
– Developed in Microsoft™ Excel Interface
– Used for ad-hoc runs for evaluation of “what-if” scenarios e.g.:• Different equipment line-up
• Firing different fuels in boilers
• Boiler fouled/clean (adjusting boiler efficiency)
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The AMS Optimizer ApplicationThe AMS Optimizer Application
• Optimization System Architecture– Asynchronous processes
running online.
– Model includes:• Utilities plant
• Plant demands & constraints
• Plant Economics
– Data is read in real-time from the plant InfoPlus data historians
– Optimizer runs every 5 minutes in open-loop mode
– Optimizer results are archived in the site InfoPlus historian and displayed on the user interface (Aspen Process Explorer)
Engineering Interface
Plant Model
Site Data Historian
Offline
Optimiser
AMS Process Manager
Model database
Data conditioning & validation (AMS Data Manager)
Online User Interface
Offline Tool Interface
Online Optimiser
Model Updating
Plant Data Economic Data
InfoPlus
Optimizer Results
Local Data Server (PI)
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Project Execution & Benefits AuditProject Execution & Benefits Audit
• Optimizer was designed, built and installed on site in 5 months, according to plan
• System went live after a 4-week commissioning period
Kick off
Design
System Build
Commissioning
Benefits Audit
Close-Out & Support
M5M4M3M2M1 M6
Design Approval
Interim Site Acceptance
Final Acceptance
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Project Execution & Benefits AuditProject Execution & Benefits Audit
• Project Phases– Kick-Off: Emerson team visit site
for admin/technical meetings & data collection
– Design Phase: System designs and test specification produced and reviewed with Company
– Build Phase: Optimization system built & tested and installed on site via remote link from Emerson.
– Site Commissioning: Emerson team on site for final model tuning and system review with Company, and delivering training to Operations team
– Benefits Audit: System goes live and operators are trained. Data is collected before and after system goes live to measure recovery of benefits
Kick off
Design
System Build
Commissioning
Benefits Audit
Close-Out & Support
M5M4M3M2M1 M6
Design Approval
Interim Site Acceptance
Final Acceptance
[File Name or Event]Emerson Confidential27-Jun-01, Slide 17
Project Execution & Benefits AuditProject Execution & Benefits Audit
• Online Optimizer Benefits Audit– Baseline opportunity (deviation
in operating cost between actual and optimum operation) is calculated using historical plant data for a 6 month period
– Specific baseline is calculated using data when optimizer is running online but results are not being implemented
– Operators given hands-on training on use of optimizer and optimizer goes live
– Final measurement taken and cost deviation is recalculated to determine open-loop system benefit
– Benefits recovery is ratio of available benefit in Open-Loop (4) and Specific Baseline (2) periods
– Benefits recovery factor is applied to Baseline opportunity (1) to determine annualized system benefit
Opportunity Value(Optimiser Directed
Operation)
Opportunity Value(Current
Operation)
Optimiser Benefit
How the plant would have been operated without
the optimiser
Current operating cost
Operating cost at optimum
Operating Cost$/h
Time (Weeks)Specific Baseline Period
Open-Loop Operation
PeriodTraining Period & initial use
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Business ResultsBusiness Results
• Audited benefit of over $612,000 /yr from the online AMS Optimizer
• AMS Optimizer was used to quantify losses due to required repair work on the burners in one of the boilers
• AMS Optimizer now forms part of the core decision making tools in the normal operation of the utilities plant equipment
Plant Type:Site UtilitiesCo-generation
Scope:Online OptimizerOffline Tool
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Energy Optimization Example -Freeport ChemicalEnergy Optimization Example -Freeport Chemical
• Project: Consulting and Real-Time Optimizerto address
– 4 cogen plants with 12 Gas Turbines 7 Steam Turbines & 2 Fired Boilers producing over 1200 MW of power
– Major issue was rapid price changes
• Result:
– Optimally respond to energy price and demand changes
– Predict cost of operating degraded equipment
– Online Selection Optimizer to identify optimal equipment line up
– $ 5.3M per annum in benefits across 4 sites
[File Name or Event]Emerson Confidential27-Jun-01, Slide 20
Access results for each model/optimizer process on plant-by-
plant basis
View optimizer status and performance data
View results on per-equipment basis
View key performance results on summary screens
[File Name or Event]Emerson Confidential27-Jun-01, Slide 21
….and these are the corresponding model
predicted values
This overview screen displays
results for a specific plant
This column displays equipment name with key control
variables
This column displays variables on/off flags
These are the lower limit
values for the variables
These are the upper limit values for the
variables
These are current “live” measured
values…
These are the optimizer setpoints
This section displays the
optimizer status
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The overview screen displays specific
equipment resultsThe results layout at
each level is the same for ease of use.
Key Performance Indicators (KPIs)
are also displayed
HRSG Steam results shown
here
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This trend shows the current and
optimized operating cost
This line shows the actual operating cost using the optimizer
This line is the operating cost without using the optimizer.
The result across the 4 sites is an improvement
of $5.3M per annum
[File Name or Event]Emerson Confidential27-Jun-01, Slide 24
SummarySummary
• Complex utilities plant supplying steam and electricity to meet site demands
• Boilers capable of firing multiple fuels
• Complex process economics and contracts
• Tool required to make real-time recommendations of most economical operation
• AMS Optimizer solution implemented
• Solution was built and delivered to site according to plan (within 5 months) thus enabling quick realization of benefit for Company