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

Combustion Systems FIELD TEST OF A 1.5 MW INDUSTRIAL GAS TURBINE WITH A LOW EMISSIONS CATALYTIC COMBUSTION SYSTEM Ralph A. Dalla Betta Tim J. Caron Sarento G. Nickolas John Chamberlain ChrisK. Weakley Agilis Group, Inc. Kare Lundberg Catalytica Combustion Systems, Inc. Kevin Greeb Woodward Governor Company

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 330°C 450°C 1300°C 1010°C 630°F 840°F 2370°F 1850°F Fuel Inject or Preburner Burn out Cat alyst Compressor Turbine zone Bypass/ cooling air � 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 Catalytica Combustion Systems, Inc.

One Aspect of Catalyst System Temperature controlled by “Integral Heat Exchange” structure that limits catalyst temperature below adiabatic combustion temperature Monolith Washcoat layer Metal or ceramic Catalytic substrate Gas flow Non-Catalytic High surface area oxide support Catalytic component dispersed on the oxide support Catalytica Combustion Systems, Inc.

Integral Heat Exchange Integral heat exchange (IHE) limits catalyst temperature Bulk flow Reactants Products Rxn heat ² Tad Ts = Tin + Boundary layer 2 Catalyst Foil substrate Boundary layer Rxn heat Bulk flow • Solid cross-section essentially isothermal • Equal heat transferred to catalyzed and non-catalyzed channels • Maximum conversion = 50% • Maximum wall temperature = Tin + ² Tad 1 2 • 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) Catalytica Combustion Systems, Inc.

XONON 1 Catalyst performance and operating line • Measured on Sub-scale rig at operating conditions Load ( %) 0 22 36 55 70 84 10 0 8 0 0 CO < 1 0 ppm Cat alyst inlet t empe rat ure ( °C) 7 0 0 Operat ing line Syst em limit 6 0 0 UHC < 1 0 0 ppm 5 0 0 UHC < 1 0 0 0 ppm 4 0 0 Compressor discharge 3 0 0 7 0 0 7 0 0 8 0 0 9 0 0 1 0 0 0 1 1 0 0 1 2 0 0 1 3 0 0 Burnout zone t emperat ure ( °C) Catalytica Combustion Systems, Inc.

XONON design flexibility All of fuel Inlet Outlet Homogeneous catalyst catalyst combustion All of air Tad Surface Temperature Gas • High activity • Higher wall T (design Sufficient time to: • Low lightoff T limits max wall T) • Complete CH4 combustion • Designed for low wall T • High outlet gas T • Complete UHC and CO burnout Catalytica Combustion Systems, Inc.

Catalyst fuel injector/mixer Preburner exit gas sample Combustor cross Preburner section Slots Catalyst inlet gas sample Primary tube exit Secondary tube Stage 1 catalyst Stage 2 catalyst Post catalyst reaction zone Infrared camera 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 of the primary and secondary prior to catalyst inlet Catalytica Combustion Systems, Inc.

Preburner: Perspective View T angnetial entry Dilution flow primary mixing tube Preburner liner Axial entry secondary mixing tube 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 Dynamometer water Air intake cooling tower Air intake Gear box Air eductor Dynamometer 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 over 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 300 30 25 250 CO and UHC (ppm) 20 200 NOx (ppm) 15 150 10 CO NOx 100 5 50 0 UHC 0 -5 0.6 0.7 0.8 0.9 1 1.1 Equivalence ratio Catalytica Combustion Systems, Inc.

Secondary Performance � Primary Ø=0.86 � Measured at preburner exit 4000 5 4 UHC UHC and CO (ppm) 3000 NOx (ppm) 3 2000 2 NOx 1000 1 CO 0 0 0 0.1 0.2 0.3 0.4 0.5 Equivalence ratio Catalytica Combustion Systems, Inc.

Secondary Performance � Primary Ø=0.86 � Measured at preburner exit 150 5 Temperature rise (°C) 125 Temperature 4 rise 100 NOx (ppm) 3 75 2 50 1 25 NOx 0 0 0 0.1 0.2 0.3 0.4 0.5 Equivalence ratio 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 8 Catalyst OD 1.00 O 6 1.00 O 0.99 1.00 O O 4 Results 0.99 0.99 O O 1.00 -Coordinate 2 O Relative F/A ratio 1.01 1.00 1.00 1.01 0 O O O O Min 0.991 Max 1.008 Y -2 1.00 O 1.00 1.00 O O Range ± 0.9% -4 1.00 0.99 O O 1.00 O -6 1.00 O -8 -8 -6 -4 -2 0 2 4 6 8 X-Coordinate Catalytica Combustion Systems, Inc.

Infrared Image at Full Load (EGT limit) 891 C 903 C Uniformity = ~ 75 C 870 C 994125c4 Catalytica Combustion Systems, Inc.

Engine Performance � Measured at engine exhaust � Corrected to 15% O 2 20.0 100 18.0 UHC 16.0 80 UHC and CO(ppm) 14.0 CO NOx (ppm) 12.0 60 NOx 10.0 Raw NOx 8.0 40 6.0 4.0 20 2.0 0.0 0 0 200 400 600 800 1000 1200 1400 Load (kW) 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 Catalytica Combustion Systems, Inc.