Real-time Optimization at US Chemical Utilities Plant Reduces Operating Costs. Fabian Robin Marcelo Carugo

Transcription

1 Real-time Optimization at US Chemical Utilities Plant Reduces Operating Costs Fabian Robin Marcelo Carugo

2 Introduction 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 27-Jun-01, Slide 2

3 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. 27-Jun-01, Slide 3

4 The 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. 27-Jun-01, Slide 4

5 The 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 27-Jun-01, Slide 5

6 Real-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 OPTIMIZER Off-Line PLANT OPTIMIZER Open-Loop PLANT OPTIMIZER Closed-Loop 27-Jun-01, Slide 6 PLANT

7 The 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 27-Jun-01, Slide 7

8 The 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 27-Jun-01, Slide 8

9 The 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 27-Jun-01, Slide 9

10 The 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 27-Jun-01, Slide 10

11 The AMS Optimizer Application Supplied application consists of: Online Optimization System Offline Optimization Tool 27-Jun-01, Slide 11

12 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 27-Jun-01, Slide 12 The AMS Optimizer Application

13 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) The AMS Optimizer Application 27-Jun-01, Slide 13

14 The 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) 27-Jun-01, Slide 14 InfoPlus Model Updating AMS Process Manager Plant Model Model database Data conditioning & validation (AMS Data Manager) Plant Data Economic Data Site Data Historian Online Optimiser Offline Optimiser Optimizer Results Local Data Server (PI) Offline Tool Interface Engineering Interface Online User Interface

15 Project 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 M1 M2 M3 M4 M5 M6 Kick off Design Design Approval System Build Commissioning Interim Site Acceptance Benefits Audit Final Acceptance Close-Out & Support 27-Jun-01, Slide 15

16 Project 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 M1 M2 M3 Interim Site Acceptance M4 Final Acceptance M5 M6 Design Approval 27-Jun-01, Slide 16

17 Project 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 27-Jun-01, Slide 17 system benefit Current operating cost Operating Cost $/h Operating cost at optimum Specific Baseline Period Opportunity Value (Current Operation) Opportunity Value (Optimiser Directed Operation) Time (Weeks) Training Period & initial use How the plant would have been operated without the optimiser Open-Loop Operation Period Optimiser Benefit

18 Business Results Plant Type: Site Utilities Co-generation Scope: Online Optimizer Offline Tool 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 27-Jun-01, Slide 18

19 Energy Optimization Example - Freeport Chemical Project: Consulting and Real-Time Optimizer to 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 27-Jun-01, Slide 19

20 Access results for each model/optimizer process on plant-byplant basis View results on perequipment basis View key performance results View optimizer status on summary screens and performance data 27-Jun-01, Slide 20

21 These are the This column lower displays limit variables values on/off flags for the variables This overview These are.and current screen these displays These are are the the live measured results corresponding for optimizer a specific model setpoints values predicted plantvalues This column displays equipment name with key control variables These are the upper limit values for the variables This section displays the optimizer status 27-Jun-01, Slide 21

22 HRSG Steam results shown here The overview screen The results layout displays at specific each level is the equipment same results for ease of use. Key Performance Indicators (KPIs) are also displayed 27-Jun-01, Slide 22

23 This trend shows the current This and line is the optimized operating operating cost without using cost the optimizer. This line shows the actual operating cost using the optimizer The result across the 4 sites is an improvement of $5.3M per annum 27-Jun-01, Slide 23

24 Summary 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 27-Jun-01, Slide 24

25 The End Any Questions / Comments? 27-Jun-01, Slide 25