Large Scale Energy Recovery

Steve ConnorFebruary 27, 2013

Definitions

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kWhA kilowatt hour is equal to 1000 watts

MWA Megawatt is equal to 1,000,000 watts or 102 boiler horsepower

HRSGHeat Recovery Steam Generator

CHPCombined Heat & Power for either direct or indirect energy recovery and application of the thermal energy to the process. This might also be termed cogeneration.

Combined CycleA form of CHP which in most cases captures thermal energy through a HRSG to produce steam for driving a steam turbine which in turn drives another electrical generator in addition to the one driven directly by the gas turbine.

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Traditional PlantWater

Fuel

Steam or Hot Water Cooling/Heating

Building or FacilityGrid

Electricity

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Traditional CHP Plant

Water

Fuel

Steam or Hot Water Cooling/Heating

Building or Facility

Grid

SteamTurbine Generator

Electricity

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CHP Plant w/ HRSG

Water

Fuel

Steam or Hot Water Cooling/Heating

Building or Facility

Grid

ElectricityHot Exhaust

Gases

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CHP Plant w/ HRSG

Water

Fuel

Steam or Hot Water Cooling/Heating

Building or Facility

Grid

ElectricityHot Exhaust

Gases

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Thermal Oxidizer

Gas Turbine

• 500kW – 250 MW

• Simple cycle

• Simple cycle w/ HR

• Simple cycle w/ HRSG

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Typical Industries Generating Power

• Aerospace & Military• Chemical &

Pharmaceutical• Pulp & Paper• Petroleum & Refining• Large Industrials• Large Medical Centers• Large office Complexes• Universities

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What are the Main Drivers?

• Energy cost reduction• Peak Demand avoidance

• Electrical reliability (power outages)

• Supplement existing steam capacity

• Backup reliability (critical load)

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Absorption chiller

Putting things in Perspective…

• 5 MW load• 150,000#/HR @ 900 degrees F.• 25,000#/HR• 725 HP

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Putting things in Perspective…

$1,170,774.00!! 25,000#/HR

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What is the cost of steam?

2011 Steam Rate ($15.00/1,000 lb)

Environmental Sustainability & Emission Reduction

• 400,000 commercial/industrial boilers• 60% over 20 years old (75% efficient)• Consume 33 Quads/Yr.• 25% of world’s energy• 21 MM Brl’s/day • Waste 400,000,000 brls @ 10%• BP Gulf Oil Spill = 172,000,000 gallons• We burn less, we pollute less. • Conservation is key…

Specification Requirements

• Turbine driving a 5 MW generator• 25,000#/HR• High and low pressure steam

• Pumps• Compressors• Hot water (Hx)

• Small space requirement• Optimum efficiency• Ease of maintenance

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Slant HRSG

GasTurbine

Inlet

Water (Lower)Drum

Water ColumnLevel Gauge

Main Steam Outlet

External Downcomer

Bare & FinnedTube Heating

Surfaces Inlet Flange

Flue Gas Outlet

Base Frame

Steam (Upper) Drum

Outer Casing

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Slant Design HRSG

Heat transfer coefficient

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Vertical Drum over Drum HRSG

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Drum over Drum Cross Flow

CombustionGas Turbine

Inlet

Diverter

DiverterStack

DiverterSilencer

DuctBurner

SlantHRSG

Economizer

Exhaust Stack

SteamOutlet

Feedwater Inlet

Fresh AirFan

Slant HRSG

Slant Design HRSG

• Maintenance• . No baffles• . Manways• . Access doors

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Another option

VC Type HRSGs

Thermal Oxidizer, CHP

• 10 MW Generator• 50,000# of steam • Superheat• Roof penetration

problems• Supplemental firing• Excellent Thermal

Efficiency

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GasTurbine

Inlet

Water (Lower)Drum

Safety & VentValve Connections

Main Steam Outlet

IntegralFurnace

w/ Viewports

Superheater

Flue GasOutlet

Base BeamSupports

Steam (Upper)Drum

OuterCasing

O Design HRSG

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HRSG w/ Supplemental & Economizer

O Type HRSG

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Full General Arrangement

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HRSG Type O

Membrane Wall Construction with Top Outlet

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Membrane Wall Construction

Finned and Staggered Tube Pattern

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Fluids• Reynolds Number is ratio between viscous & inertial forces.

CombustionGas Turbine Inlet

DuctBurner

MAXFIRE® HRSG

Flame Scanners

(One per Dist.Runner)

DuctworkFlange

IgnitionTransformer Fuel Gas

Injection Manifold

Fuel GasDistribution

(Runner)Gas Fuel

Inlet

Ignitors(One per Dist.

Runner)

PneumaticActuator

For Fuel Valve)(off skid typical)

TurbineExhaustBaffles

Duct Burner

Duct Burner

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5 – 15 MW HRSG Packages

Dual Pressure Modular HRSG W/ Integral DA

• Fired HP Steam Flow

• 120,000#/HR @ 800°F & 700 psig

• LP Steam Flow• 20,000#/HR @ 80 psi• Integral DA • SS Condensate Htr

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190,000 lb/hr @ 750°F & 760 psig HRSG

Modular Series - HRSG

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Modular Design with Superheater,Elevated Drum, & Economizer

Waste Heat Watertube Boilers

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SCR System Components

3838

NO

O

NO

O

N O

N O

N O

NO

O

NH

HH N O

NH

HH

OHH

OHH

OHH

N N

N N

Ammonia metering and dilution skid (anhydrous shown)

AIG (ammonia injection grid)

Catalyst Bed

Anhydrous

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Slant / VC Series Package HRSGs

Outlet Transition Duct withflow distribution device to ensure uniform flow to the duct burner.

In-house CFD capabilitiesexample from a Solar Mercury 50 with top outlet and axially flow through HRSG.

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Taking Advantage of Technology

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Furnace Modeling

Controls

• BMS (Burner Management)

• Combustion Control & Monitoring• Three Element FW• VFD (FW pumps)• Stack damper position• Diverter operation• Superheat • SCR• Economizer• Condensate heater• Pressure s & Temperatures• NOx & CO readings

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HRSG Burner Management System

Provides safe interlock w/ Turbine• Initial purge by Turbine• Gas turbine enabled• Diverter closed/Damper open• Control/safety limits on

HRSG closed• Turbine gas flow proven• Duct burner enabled for 2nd

purge • Pilot igniter energized• Pilot proven• Main gas valve(s) energized • Main flame proven• Monitor and manage

operating & safety limits 43

CCS & BMS

Integrated Controls

Combustion Control & Monitoring• Three Element FW• VFD (FW pumps)• Stack damper position• Diverter position• Fresh air fan operation• Superheat • SCR• Economizer• Condensate heater

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Hawk 5000 Plant Master

Returning WEALTH to the Business

Energy $ SpendEnergy Consumption• Committed• At Risk

• Buy & waste?• Pay to avoid?

Summary

• On-site power generation is more efficient than power from the Utility

• Over 90% of the thermal energy coming from a heat source is recoverable.

• CHP systems are highly engineered to include Energy source, HR, Ducting, Emission control, Stack/Recovery, and Controls

• Supplemental firing can be over 100%• The HRSG design choice and configuration varies by

specific application• The Fuel and Emission saving potential is substantial• Needs to be justified using sound financial metrics.• Critical factor is choosing the correct partner to engineer

and provide the system.

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Contacts for additional information:

Greg KaupSales Manager, ERI

gkaup@cleaverbrooks.com(402) 434-2035