Optimization of a Cogeneration System in the Automotive Industry

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1 Optimization of a Cogeneration System in the Automotive Industry Steve Spentzas Energy Resources Center University of Illinois at Chicago Midwest CHP Application Center

2 Overview Cogeneration in the Automotive Industry What is Cogeneration? Why Co-generate? Power Generation Equipment Heat Recovery Case Study Optimization of a Cogeneration System Conclusion

3 Cogeneration in the Automotive Industry The Automotive Industry: Engine Manufacturers Part Manufacturers Assembly Plants Ideal for Cogeneration: High Utility Costs Coincident Thermal and Electrical Loads Many Recycled Energy Applications

4 What is Cogeneration? Cogeneration (Cogen) is An Integrated System Located at or Near a Building/Facility Providing a Portion of the Electrical Load and Utilizes the Thermal Energy for Process or Space Heat Process or Space Cooling Direct Applications

5 What is Cogeneration?

6 Why Co-generate? Reduce Energy Costs Improve Electric Reliability Improve Power Quality Improve Economics for Enhancing Indoor Air Quality Improve Environmental Quality Ability to Recycle Waste Heat Streams

7 Power Generation Equipment Reciprocating Engines Combustion Turbines

8 Power Generation Equipment Microturbines Steam Turbines

9 Power Generation Equipment Prime Movers Reciprocating Engines Combustion Turbines Capacity Range (kw) 100-2,000 1,000-10,000 Efficiency (%) Installed Cost ($/kw) $1,800-$1,000 $1,500-$800 Low Grade Heat Recovery Hot Water (180 o F-212oF) Hot Water (over 180 o F) High Grade Heat Recovery Low Pressure Steam (15 psig) Low Pressure Steam (150 psig) O&M Costs ($/kwh) $0.015-$0.012 $0.008-$0.005 Prime Movers Steam Turbine Microturbines Capacity Range (kw) Efficiency (%) Installed Cost ($/kw) $300-$700 $2,000-$1,000 Low Grade Heat Recovery --- Hot Water (180 o F-212oF) High Grade Heat Recovery --- Low Pressure Steam (15 psig) O&M Costs ($/kwh) $ $ $0.015-$0.001

10 Heat Recovery Heat Recovery Steam Generator (HRSG)

11 Absorption Chillers Heat Recovery

12 Heat Recovery Direct Use of Exhaust Gasses

13 Case Study Engine manufacturer in the Midwest US: 8,000,000 square feet The facility spends: $4,500,000/yr in utilities Electrical Costs: $2,000,000/yr Natural Gas Costs: $3,500,000/yr Cogeneration system was installed over a decade ago Cogeneration system had a paid its self-back in 7.5 years

14 The Cogeneration System 9.2 MW Cogeneration System 12 Caterpillar reciprocating engines 6 HRSGs (1,200 lbs/hr ea; 7,200 lbs/hr total) Supplies base summer load Boilers fire during winter 1.6 MW Backup Diesel Generator

15 Understanding Electrical Demand 9,500 9,000 8,500 8,000 Demand (kw) 7,500 7,000 January February March April May June July August September October November December Maximum Electrical Demand as Seen from the Utility

16 Thermal Equipment 3 Oversized Boilers (30 psig steam) 5,000 lbs/hr-18,000 lbs/hr seasonal steam load 2/3 of load for space heating Domestic hot water Very little process steam usage

17 May June July August September October November December January February March April 20,000 18,000 16,000 14,000 12,000 10,000 8,000 6,000 4,000 2,000 0 Thermal Equipment Base Load Heating Load Steam Flow (lbs/hr)

18 Thermal Equipment Decentralized chilled water supply 500 Tons Total, 1,300 gpm (44 o F-54 o F) Engineering Testing Department (200 tons) VAV System (300 tons)

19 Steps to Optimize Plant Improved Utility Pricing Natural Gas: Annual Contracting Monthly Variable Commodity Rate Electrical: Operate Under General Service Energy Pricing Operate With Day-Ahead Energy Pricing Operate With Real-Time Energy Pricing

20 Steps to Optimize Plant Improve Electrical Capacity Reduce plant energy demand Add generating capacity Install power factor correction

21 Steps to Optimize Plant Increase Heat Recovery Convert Distributed Generation units to Cogeneration units (additional HRSGs) Install absorption chilling Reduce winter steam load to meet max thermal output of cogeneration plant

22 Conclusions Cogeneration at this plant: Reduces Energy Costs Improves Electric Reliability Provides Flexibility for Expansion Reduced Overall Environmental Emissions Facilitates Use of Excess Energy Streams Gives the Facility More Control Over Utility Costs

23 Conclusions How to optimize a cogeneration system: Increasing heat recovery increases cost savings Installing absorption chilling increases heat recovery and increases cost savings Load shedding increases capacity and to avoids the need for additional generators: Increased power factor Reduced electric load from an absorption chiller

24 Midwest CHP Application Center Formed by U.S. DOE in 2001 Goal is to provide Education, Technical Information, and Application Assistance on the concepts and technologies of CHP Services (12) twelve state Midwest region (IL, IN, IA, KS, MI, MN, MO, NE, ND, OH, SD, WI) Formed close relationships with state energy offices, engineering firms, utilities, and other key CHP stakeholders Contact Information Steve Spentzas: Phone: (312) Energy Resources Center Located at University of Illinois at Chicago (UIC) Provide Cost Efficient, Innovative and comprehensive energy solutions to Our Clients Create Effective Working Partnerships With Academia, Industry, Public Institutions, Local and Federal Agencies, Energy Consortiums and Foundations Maintain a Strong Commitment to and Actively Implement Innovative Public Outreach and Education Contact Information William Worek (Director): wworek@uic.edu Phone: (312)