steam powered energy conservation at
TRANSCRIPT
Michigan WEA, 2013 Conference
June 24, 2013
Peter V. Cavagnaro, P.E., BCEE
Johnson Controls, Inc.
Andrew T. Cronberg, P.E.
City of Fort Worth
Alan Bush, P.E., BCEE
AECOM
Steam Powered Energy
Conservation at
Fort Worth’s Village Creek
WRF
First Construction 1950’s
Qdesign = 166 MGD
Qaverage = 105 MGD
Single Stage A/S w Nitrification
Anaerobic Digestion of Wastewater Solids
Village Creek
Wastewater Reclamation Facility
The Project
The project was delivered using the Energy Performance
Contracting (PC) model
Energy savings funded all improvements identified in this
project
Johnson Controls was the Energy Services Company
(ESCO) for the project
Engineering provided by AECOM, Freese & Nichols, Vic
Weir Consulting, and CDM Smith
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Project Cost $35 million
Annual Utility Savings $2.56 million
Annual O&M Impacts $0.24 million
Total Annual Benefits $2.80 million
Simple Payback 12.4 years
4
Costs & Benefits
Project Drivers in 2007
• City Wide Effort to Comply with State Legislation
• SB12 (2007) renewed in 2011 via SB898
Extended the SB5 Goal of reducing annual electricity
consumption by 5% for 6 more years, from 2007-2012
“Cost-Effective” Electricity-Based Energy-Efficiency
Measures
Legislation was for air quality improvements
• State Energy Conservation Office (SECO)
Annual Reporting Requirement continues, with 2007
as the Baseline
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Project Drivers
• A list of projects competing for limited capital
dollars
• Control of operating budget
• The Water Department represented 47% of the
City’s energy expenditures
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City of Fort Worth PC to Date
Reducing electric consumption 37% in over 100
City facilities $93 million in total savings guaranteed over the
contract term Secured approx. $2 million in utility rebates
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Department Project Cost
Transportation & Public Works (6 Phases) $34 million
Water (Village Creek WRF) $35 million
Total $69 million
Village Creek Electric Utility
In FY 2008 the City purchased $3.4M for electricity
at Village Creek
Total Demand averaged 7 to 8 MW
• Aeration Blowers
• Primary Effluent Pumps
• Other pumps & Odor Control
Aeration Blowers the main consumer
• Three to four blowers operated at a time
• 1 - 2250 HP
• 2 to 3 - 1,000 HP
… a Net Zero Energy
Village Creek Facility!
Goal
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1 - Turn off electric motor blowers
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Pre-project: 2-3 @ 1000 HP + 1 @ 2200 HP
2 – Reduce flaring of digester gas
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3 – Recover Gas Turbine Waste Heat
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Journey to Net Zero began in the 1960’s
Digester Gas fueled Engine Blowers & Generators
Some heat recovery for anaerobic digesters
Photo courtesy of Vic Weir Consulting, Inc.
In FY02, the City’s wastewater plant began utilizing a
biogas-fired turbine-generator system
and continued in 2002
Provided
about 50%
the
electricity
needs
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Journey to Net Zero Energy,
Phase III
FIM #3A: Codigestion
FIM #4: SCADA System
FIM #6E: HVAC
Improvements FIM #6D:
Pump Operation
Improvements
FIM #6H:
Power
Factor
Correction
FIM #1:
Aeration Diffusers
FIM #5: Anoxic Zones FIM #6A: Aeration
Control Improvements
FIM #2: Heat
Recovery
FIM #3B:
Linear Motion
Mixers
Dedicated facility:
Truck unloading pad
30,000 gal mix tank
Two 8,000 gal batch tanks
Recirculation, transfer and feed
pumps (six total)
PLC control feeds each digester
once/hour
Receiving up to 9 x 6,000 gal
trucks / day
VCWRF Co-Digestion System
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HYDRO DISK AT MID DEPTH
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Anaerobic Digestion Improvements
Type: Linear Motion Mixers
No: Six (6) digesters - One (1) mixer per digester
Power: 10 HP per mixer
Hydro Disk: 7-ft diameter, 18-in travel, 30 cycles per min
18-inch vertical travel
7-ft diam
90-ft diam digester
Linear Motion Mixer
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LMM Drive
Scotch-yoke & cam
mechanism
Heat Recovery Steam Generator
(HRSG) on Turbine Exhaust
generates steam
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Waste Heat Recovery
The duct burner uses digester
gas to boost the temperature of
the turbine exhaust. The higher
temperature is needed to
produce enough steam to power
two steam turbines
Waste Heat Recovery
Duct Burner
Steam Turbine Powered Blowers
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2 unused 1200 HP 31,000 cfm blowers
Rehab’d and equipped with steam turbine drivers
Aeration Infrastructure renewed
New 9-in membrane diffusers
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PTFE coating
Include a 10-year
manufacturer
material warranty
Anoxic Zones & Nitrate Rich Recycle
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SCADA System Replacement
Project included the replacement of the existing Johnson
Yokogawa SCADA system with a new Emerson Ovation
SCADA Distributed Control System
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ANAEROBIC DIGESTERS
GAS TURBINE
DRIVEN
GENERATORS
SOLIDS TO
DEWATERING
HEAT RECOVERY
UNIT
UNUSED BLOWERS
HEX WASTE HEAT FROM
TURBINE EXHAUST
HEATS DIGESTERS
2250
MOTOR DRIVEN
BLOWERS
1000
1000
1000
AERATION SYSTEM
OVER 20 YEARS OLD
SCADA SYSTEM OVER
20 YEARS OLD
Fitting the
pieces together
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ANAEROBIC DIGESTERS
GAS TURBINE
DRIVEN
GENERATORS
SOLIDS TO
DEWATERING
HEAT RECOVERY
UNIT
UNUSED BLOWERS
HEX WASTE HEAT FROM
TURBINE EXHAUST
HEATS DIGESTERS
2250
MOTOR DRIVEN
BLOWERS
1000
1000
1000
AERATION BASINS
DIFFUSERS REPLACED
ANOXIC ZONES ADDED
NEW SCADA SYSTEM
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ANAEROBIC DIGESTERS
CLEANED & ENHANCED
MIXING
ADDITIONAL DG
TO OPERATE
EXISTING GAS
TURBINE DRIVEN
GENERATORS
REDUCTION IN
SOLIDS TO
DEWATERING
HEAT RECOVERY
STEAM GENERATOR
1 - STEAM TURBINE
DRIVEN BLOWER
CONDENSATE
RETURN
HEX WASTE HEAT FROM
CONDENSER HEATS
DIGESTERS
2250
MOTOR DRIVEN
BLOWERS
1000
1000
1000
NEW SCADA SYSTEM
AERATION BASINS
DIFFUSERS REPLACED
ANOXIC ZONES ADDED
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HIGH
STRENGTH
WASTE
RECEIVING
ANAEROBIC DIGESTERS
CLEANED & ENHANCED
MIXING
ADDITIONAL DG
TO OPERATE
EXISTING GAS
TURBINE DRIVEN
GENERATORS
REDUCTION IN
SOLIDS TO
DEWATERING
ADDITIONAL DG
TO OPERATE
DUCT BURNER
HEAT RECOVERY
STEAM GENERATOR
2 - STEAM TURBINE
DRIVEN BLOWERS
CONDENSATE
RETURN
HEX WASTE HEAT FROM
CONDENSERS HEATS
DIGESTERS
2250
MOTOR DRIVEN
BLOWERS
1000
1000
1000
NEW SCADA SYSTEM
AERATION BASINS
DIFFUSERS REPLACED
ANOXIC ZONES ADDED
$0
$50,000
$100,000
$150,000
$200,000
$250,000
$300,000
$350,000
$400,000
$450,000
$500,000
0
1,000,000
2,000,000
3,000,000
4,000,000
5,000,000
6,000,000
7,000,000
8,000,000
9,000,000
CO
NS
UM
PT
ION
(K
WH
)
TOTAL PURCHASED (kWh) TOTAL GENERATED DIESEL ENGINE GENERATORS
TOTAL GENERATED (TG1 + TG2) SAVINGS
Performance to Date
Electric Consumption (1995-2013)
Acknowledgements
Fort Worth Water Department
Sebastian Fichera, REM
Assistant Water Director
Madelene Rafalko, P.E.
Senior Professional Engineer
Gary LaGassey
Lead Operator
Ana Pena, Ph.D., P.E.
Jerry Pressley
Luke Matus, I&C
Jake Pena, I&C
Ron Carlson, P.E.
Johnson Controls Team
Harry Romine, P.E., C.E.M.
Account Executive
Dennis Gallagher
Construction Manager
Sarah Phillips, P.E.
Project Development Engineer
Velton Ellis
Construction Superintendent
Vic Weir Consulting, Inc.
Vic Weir, P.E.
Freese and Nichols, Inc.
Ted Gay, P.E.
Leonard Ripley, Ph.D., P.E.
Clay Rahn, P.E.
AECOM
Randy Wodrich
Gary Breitwisch, P.E.
The men and women who
constructed and who operate
the facilities.
CDM Smith
Dean Gorell
Nate Mogaru
Thank you
Peter V. Cavagnaro, P.E., BCEE
Project Development Consultant
Johnson Controls, Inc.
734-255-5523
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