Combustion Systems FIELD TEST OF A 1.5 MW INDUSTRIAL GAS TURBINE - - PowerPoint PPT Presentation

FIELD TEST OF A 1.5 MW INDUSTRIAL GAS TURBINE WITH A LOW EMISSIONS CATALYTIC COMBUSTION SYSTEM

Ralph A. Dalla Betta Sarento G. Nickolas

• ChrisK. Weakley

Kare Lundberg Catalytica Combustion Systems, Inc.

Combustion Systems

Tim J. Caron John Chamberlain Agilis Group, Inc. Kevin Greeb Woodward Governor Company

Catalytica Combustion Systems, Inc.

Program Objectives and Strategy

Combustor to be a demonstrator of catalytic technology

– Materials selected to minimize development time – No size limitations

Basic engine/combustor approach

– No modifications to gas turbine – Combustor change out at combustor flange – Natural gas fuel only

Performance targets

– Emissions over 90 to 100% load range and wide ambient NOx < 3 ppm CO < 5 ppm UHC < 5 ppm – Minimal impact on turbine performance

Combustor outlet temperature of 1300°C (2400°F) to demonstrate

catalytic combustion technology for wide range of engines

Catalytica Combustion Systems, Inc.

Schematic of combustor configuration

Preburner provides required catalyst inlet temperature Catalyst fuel injector produces a uniform fuel/air mixture for the

catalyst

High post catalyst temperature oxidizes CO to < 10 ppm Bypass and cooling air provides required turbine inlet temperature

Compressor Preburner Cat alyst Burn out zone Turbine Bypass/ cooling air Fuel Inject or

330°C 630°F 450°C 840°F 1300°C 2370°F 1010°C 1850°F

Catalytica Combustion Systems, Inc.

One Aspect of Catalyst System

Metal or ceramic substrate Washcoat layer Gas flow High surface area

• xide support

Catalytic component dispersed on the oxide support

Monolith Catalytic

Non-Catalytic

Temperature controlled by “Integral Heat Exchange” structure that limits catalyst temperature below adiabatic combustion temperature

Catalytica Combustion Systems, Inc.

Integral Heat Exchange

Integral heat exchange (IHE) limits catalyst temperature

Bulk flow Boundary layer Catalyst Foil substrate Boundary layer Bulk flow Products Reactants Rxn heat Rxn heat Ts = Tin + ² Tad 2

• Solid cross-section essentially isothermal
• Equal heat transferred to catalyzed and non-catalyzed channels
• Maximum conversion = 50%
• Maximum wall temperature = Tin + ² Tad
• Example:

Inlet gas T = 700°C (1290°F) Tad = 1300°C (2370°F) non-IHE wall T = 1300°C(2370°F) IHE wall T = 1000°C (1830°F) 1 2

Catalytica Combustion Systems, Inc.

XONON 1 Catalyst performance and operating line

1 3 0 0 1 2 0 0 1 1 0 0 1 0 0 0 9 0 0 8 0 0 7 0 0 7 0 0 3 0 0 4 0 0 5 0 0 6 0 0 7 0 0 8 0 0

Burnout zone t emperat ure ( °C) Cat alyst inlet t empe rat ure ( °C)

22 36 55 70 84 10 0

Load ( %)

Syst em limit CO < 1 0 ppm UHC < 1 0 0 ppm UHC < 1 0 0 0 ppm Compressor discharge Operat ing line

• Measured on Sub-scale rig at operating conditions

Catalytica Combustion Systems, Inc.

XONON design flexibility

Surface

All of fuel All of air

Inlet catalyst Outlet catalyst Homogeneous combustion

Tad

Temperature Gas

• Higher wall T (design

limits max wall T)

• High outlet gas T
• High activity
• Low lightoff T
• Designed for low wall T

Sufficient time to:

• Complete CH4 combustion
• Complete UHC and CO burnout

Catalytica Combustion Systems, Inc.

Combustor cross section

Stage 1 catalyst

Stage 2 catalyst Post catalyst reaction zone Infrared camera Primary tube exit Secondary tube Preburner Preburner exit gas sample Catalyst fuel injector/mixer Catalyst inlet gas sample

Slots

Catalytica Combustion Systems, Inc.

Preburner Design

Requirements

Temperature rise of 700°C (1200°F) during starting and

acceleration

Low emissions load range requires 80 to 150°C(150 to 270°F)

temperature rise

NOx contribution at engine exhaust < 2 ppm over low

emissions load range Design

Lean premix swirl stabilized primary

– Operates from LBO+20% to NOx limit

Lean premixed parallel secondary ignited by primary More then 50% of combustor air flow is added downstream

• f the primary and secondary prior to catalyst inlet

Catalytica Combustion Systems, Inc.

Preburner: Perspective View

Preburner liner Axial entry secondary mixing tube T angnetial entry primary mixing tube

Dilution flow

Catalytica Combustion Systems, Inc.

Catalyst Fuel-Air Mixing System

Requirements

Fuel-air mixture uniformity < ± 3% of mean at catalyst inlet No recirculation or stagnation zones that would hold flame

downstream of fuel injection Design

Preburner exhaust flow is reversed to enhance temperature

uniformity upstream of the fuel injector

Fuel is injected upstream of counter rotating swirlers

– 36 swirl vanes and 36 fuel injection pegs – Counter rotating flows promote mixing with low tangential velocity just upstream of the catalyst

Catalytica Combustion Systems, Inc.

Catalytic Module

~95% open area for

low pressure drop

All metal structure

for thermal shock resistance

Catalytica Combustion Systems, Inc.

Engine Test Cell Layout

Air intake Dynamometer water cooling tower Air eductor Dynamometer Air intake Gear box Gas turbine

Catalytica Combustion Systems, Inc.

On Engine Preburner Testing

Static pressure tap downstream of mixed preburner exhaust

used to measure gas composition

Engine operated at part load Fuel to preburner primary and secondary could be varied

• ver a reasonable range

– Must stay within catalyst operating zone – Engine was operated in speed control mode with set dynamometer load

Catalytica Combustion Systems, Inc.

Primary Zone Performance

Measured at preburner exit No secondary fuel

50 100 150 200 250 300 0.6 0.7 0.8 0.9 1 1.1

Equivalence ratio CO and UHC (ppm)

• 5

5 10 15 20 25 30

NOx (ppm)

NOx CO UHC

Catalytica Combustion Systems, Inc.

Secondary Performance

Primary Ø=0.86 Measured at preburner exit

1000 2000 3000 4000 0.1 0.2 0.3 0.4 0.5 Equivalence ratio UHC and CO (ppm) 1 2 3 4 5 NOx (ppm)

UHC NOx CO

Catalytica Combustion Systems, Inc.

Secondary Performance

Primary Ø=0.86 Measured at preburner exit

25 50 75 100 125 150 0.1 0.2 0.3 0.4 0.5 Equivalence ratio Temperature rise (°C)

1 2 3 4 5

NOx (ppm) Temperature rise NOx

Catalytica Combustion Systems, Inc.

Fuel-Air Mixer Performance

18 sampling tubes at the catalyst inlet face used to extract

mixture for analysis by FID hydrocarbon analyzer

Measurement done under constant dynamometer load with

engine in speed control mode

Measurement time was ~20 minutes Some measurement variation may arise from total fuel

variation required for engine control – Especially large at low catalyst fuel flow

Catalytica Combustion Systems, Inc.

F/A Map at Catalyst Inlet--1065 kW

Results Relative F/A ratio Min 0.991 Max 1.008 Range ± 0.9%

O O O O O O O O O O O O O O O O O O

• 8
• 6
• 4
• 2

2 4 6 8

• 8
• 6
• 4
• 2

2 4 6 8 Y

• Coordinate

X-Coordinate

1.00 1.00 1.00 1.00 1.00 0.99 0.99 1.00 1.00 1.00 1.00 1.00 1.01 1.01 1.00 0.99 1.00 0.99

Catalyst OD

Catalytica Combustion Systems, Inc.

Infrared Image at Full Load (EGT limit)

994125c4 903 C 891 C 870 C Uniformity = ~ 75 C

Catalytica Combustion Systems, Inc.

Engine Performance

Measured at engine exhaust Corrected to 15% O2

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 200 400 600 800 1000 1200 1400 Load (kW) NOx (ppm) 20 40 60 80 100 UHC and CO(ppm)

CO UHC NOx Raw NOx

Catalytica Combustion Systems, Inc.

Summary

Combustor designed and fabricated to demonstrate catalytic

combustion on a 1.5 MW industrial gas turbine

System operated at base load for 1000 hours System provides emissions levels of:

NOx < 3 ppm CO < 1 ppm UHC < 1 ppm

Catalyst shows good durability to high loading of air

contaminants

Combustor dynamics were very low