optimization of a cogeneration system in the automotive ... · optimization of a cogeneration...
TRANSCRIPT
Optimization of a Cogeneration Systemin the Automotive Industry
Steve SpentzasEnergy Resources Center
University of Illinois at ChicagoMidwest CHP Application Center
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
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
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
What is Cogeneration?
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
Power Generation Equipment
• Reciprocating Engines
• Combustion Turbines
Power Generation Equipment
• Microturbines • Steam Turbines
Power Generation Equipment
Prime Movers Steam Turbine MicroturbinesCapacity Range (kW) --- 100-400
Efficiency (%) 15-40 25-30Installed Cost ($/kW) $300-$700 $2,000-$1,000
Low Grade Heat Recovery --- Hot Water (180oF-212oF)High Grade Heat Recovery --- Low Pressure Steam (15 psig)
O&M Costs ($/kWh) $0.0015-$0.0035 $0.015-$0.001
Prime Movers Reciprocating Engines Combustion TurbinesCapacity Range (kW) 100-2,000 1,000-10,000
Efficiency (%) 24-38 24-28Installed Cost ($/kW) $1,800-$1,000 $1,500-$800
Low Grade Heat Recovery Hot Water (180oF-212oF) Hot Water (over 180oF)High Grade Heat Recovery Low Pressure Steam (15 psig) Low Pressure Steam (150 psig)
O&M Costs ($/kWh) $0.015-$0.012 $0.008-$0.005
Heat Recovery• Heat Recovery Steam Generator (HRSG)
Heat Recovery• Absorption Chillers
Heat Recovery• Direct Use of Exhaust Gasses
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
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
Understanding Electrical Demand
7,000
7,500
8,000
8,500
9,000
9,500
Janua
ryFeb
ruary
March
April
May June
July
August
Septem
ber
Octobe
rNov
embe
rDece
mber
Dem
and
(kW
)
Maximum Electrical Demand as Seen from the Utility
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
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
June
July
August
Septem
ber
Octobe
rNov
embe
rDece
mber
Janua
ryFeb
ruary
March
April
MaySt
eam
Flo
w (l
bs/h
r)
Base Load Heating Load
Thermal Equipment
Thermal Equipment
• Decentralized chilled water supply– 500 Tons Total, 1,300
gpm (44oF-54oF)– Engineering Testing
Department (200 tons)– VAV System (300
tons)
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
Steps to Optimize Plant
• Improve Electrical Capacity – Reduce plant energy demand– Add generating capacity– Install power factor correction
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
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
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
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:
[email protected]• Phone: (312) 996-4490• www.chpcenterMW.org
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):
[email protected]• Phone: (312) 996-4490• www.erc.uic.edu