The Development of a Lean-Premixed Trapped Vortex Combustor

2003 ◽  
Author(s):  
Jonathan Bucher ◽  
Ryan G. Edmonds ◽  
Robert C. Steele ◽  
Donald W. Kendrick ◽  
Blake C. Chenevert ◽  
...  
Keyword(s):  
Applied Sciences ◽  
Bluff Body ◽  
Combustion Efficiency ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Oxides Of Nitrogen ◽  
Elevated Pressures ◽  
Lean Premixed ◽  
Lean Fuel ◽  
Trapped Vortex

A lean-premixed trapped vortex combustor (TVC) has been developed and tested. The TVC was fired on methane and tested at the General Applied Sciences Laboratory (GASL). Additionally, for baseline data, a simple bluff body combustor was tested. All testing was performed at elevated pressures and inlet temperatures and at lean fuel-air ratios representative of power generation gas turbine engines. Both bluff body and TVC data showed competitive oxides of nitrogen (NOx) emissions of <25 ppm (corrected to 15% oxygen dry condition), which served as a basis for future optimization. Combustion efficiency was routinely above 99.5%. An optimized version of the TVC incorporating flame stabilizing features displayed promising emissions: NOx/CO/UHC levels were optimized to as low as 9/9/0ppm (corrected to 15% O2 dry), with corresponding combustion efficiency above 99.9%. Because of this configuration’s robust and straightforward design, it has the potential for successful integration into a prototype engine. This paper describes the combustors, their testing and the evaluation of the test results.

Investigation of Tangential Trapped Vortex Combustor

2009 ◽  
Author(s):  
Chi Zhang ◽  
Yuzhen Lin ◽  
Quanhong Xu ◽  
Gaoen Liu
Keyword(s):  
Gas Turbine ◽  
Swirling Flow ◽  
Tangential Direction ◽  
Combustion Efficiency ◽  
Combustion Stability ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Stability Range ◽  
Combustion Technology ◽  
Trapped Vortex

An innovative concept of Tangential Trapped Vortex Combustor (TTVC) applying a swirling flow to eliminate the guide vanes of the compressor and turbine in the future gas turbine engines is presented via theoretical analysis and experimental investigation. In TTVC, the airflow is mostly whirlblast, and the processes of evaporation, mixing, and chemical reaction for the liquid spray combustion take place along the tangential direction. It is shown that the TTVC operation has the potential of improving combustion efficiency, widening combustion stability range, and reducing emissions, mainly due to the effects of trapped vortex, high centrifugal force, and periodical mixing. Experimental results of the ignition and LBO limits in a small 4-cup annular TTVC operating at atmospheric pressure demonstrated that this innovative combustion technology has a good LBO limit performance to meet the requirements of advanced gas turbine engines.

scholarly journals Kinetic Modeling Study on the Combustion Characterization of Synthetic C3 and C4 Alcohols for Lean Premixed Prevaporized Combustion

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5473
Author(s):  
Solmaz Nadiri ◽  
Paul Zimmermann ◽  
Laxmi Sane ◽  
Ravi Fernandes ◽  
Friedrich Dinkelacker ◽  
...  
Keyword(s):  
Burning Velocity ◽  
Electrical Energy ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Synthetic Fuels ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Lean Premixed ◽  
Lean Fuel

To reach sustainable aviation, one approach is to use electro-fuels (e-fuels) within the gas turbine engines. E-fuels are CO2-neutral synthetic fuels which are produced employing electrical energy generated from renewable resources, where the carbon is taken out of the atmosphere or from biomass. Our approach is, to find e-fuels, which can be utilized in the lean premixed prevaporized (LPP) combustion, where most of the non-CO2 emissions are prevented. One of the suitable e-fuel classes is alcohols with a low number of carbons. In this work, the autoignition properties of propanol isomers and butanol isomers as e-fuels were investigated in a high-pressure shock tube (HPST) at temperatures from 1200 to 1500 K, the pressure of 10 bar, and lean fuel-air conditions. Additional investigations on the low-temperature oxidation and flame speed of C3 and C4 alcohols from the literature were employed to develop a comprehensive mechanism for the prediction of ignition delay time (IDT) and laminar burning velocity (LBV) of the above-mentioned fuels. A numerical model based on newly developed chemical kinetics was applied to further study the IDT and LBV of fuels in comparison to the Jet-A surrogate at the engine-related conditions along with the emissions prediction of the model at lean fuel-air conditions.

Effects of the Main Gas Path Pressure Field on Rim Seal Flows in a Stationary Linear Cascade

2015 ◽  
Author(s):  
Jeffrey Gibson ◽  
Karen Thole ◽  
Jesse Christophel ◽  
Curtis Memory
Keyword(s):  
Bluff Body ◽  
Pressure Field ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Baseline Design ◽  
Linear Cascade ◽  
Blade Row ◽  
High Degree ◽  
Effectiveness Data ◽  
Computational Predictions

Rim seals in the turbine section of gas turbine engines aim to reduce the amount of purge air required to prevent the ingress of hot mainstream gas into the under-platform space. A stationary, linear cascade was designed, built, and benchmarked to study the effect of the interaction between the pressure fields from an upstream vane row and downstream blade row on hot gas ingress for engine-realistic rim seal geometries. The pressure field of the downstream blade row was modeled using a bluff body designed to produce the pressure distortion of a moving blade. Sealing effectiveness data for the baseline seal indicated that there was little to no ingress with a purge rate greater than 1% of the main gas path flow. Adiabatic endwall effectiveness data downstream in the trench between the vane and blade showed a high degree of mixing. Extending the seal feature associated with the vane endwall indicated better sealing than the baseline design. Steady computational predictions were found to overpredict the sealing effectiveness due to underpredicted mixing in the trench.

The Effects of Ambient Conditions on Gas Turbine Emissions—Generalized Correction Factors

1978 ◽  
Vol 100 (4) ◽  
pp. 640-646 ◽  
Author(s):  
P. Donovan ◽  
T. Cackette
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Gas Turbine Engines ◽  
Correction Factors ◽  
Oxides Of Nitrogen ◽  
Ambient Conditions ◽  
Nitrogen Emission ◽  
Wide Range

A set of factors which reduces the variability due to ambient conditions of the hydrocarbon, carbon monoxide, and oxides of nitrogen emission indices has been developed. These factors can be used to correct an emission index to reference day ambient conditions. The correction factors, which vary with engine rated pressure ratio for NOx and idle pressure ratio for HC and CO, can be applied to a wide range of current technology gas turbine engines. The factors are a function of only the combustor inlet temperature and ambient humidity.

Development of a Lean-Premixed Two-Stage Annular Combustor for Gas Turbine Engines

1994 ◽  
Author(s):  
Fred C. Bahlmann ◽  
B. Martien Visser
Keyword(s):  
Gas Turbine ◽  
Turbine Engines ◽  
Emission Characteristics ◽  
Gas Turbine Engines ◽  
Two Stage ◽  
Low Emission ◽  
Lean Premixed ◽  
Annular Combustor

The development, from concept to hardware of a lean-premixed two-stage combustor for small gas turbine engines is presented. This Annular Low Emission Combustor (ALEC) is based on a patent of R.J. Mowill. Emission characteristics of several prototypes of this combustor under a variety of conditions are presented. It is shown that ultra-low NOx levels (< 10 ppm) can be reached with satisfactory CO levels (< 50 ppm).

scholarly journals Fuel Character Effects on J79 and F101 Engine Combustor Emissions

1980 ◽  
Author(s):  
C. C. Gleason ◽  
J. A. Martone
Keyword(s):  
Air Force ◽  
Hydrogen Content ◽  
Pollutant Emissions ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Oxides Of Nitrogen ◽  
Fuel Property ◽  
Fuel Atomization ◽  
Us Air Force ◽  
Point Data

Results of a program to determine the effects of fuel properties on the pollutant emissions of two US Air Force aircraft gas turbine engines are presented. Thirteen test fuels, including baseline JP-4 and JP-8, were evaluated in a cannular (J79) and a full annular (F101) combustor. The principal fuel variables were hydrogen content, aromatic structure, volatility, and distillation end point. Data analysis shows that fuel hydrogen content is a key fuel property, particularly with respect to high power emissions (oxides of nitrogen and smoke), and that low power emissions (carbon monoxide and hydrocarbons) are more dependent on fuel atomization and evaporation characteristics.

scholarly journals Approaches to the Prevaporized-Premixed Combustor Concept for Gas Turbines

1975 ◽  
Author(s):  
L. J. Spadaccini ◽  
E. J. Szetela
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Bluff Body ◽  
Porous Plate ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Operational Conditions ◽  
Lean Combustion

An experimental investigation was performed to evaluate a combustor concept which is applicable to gas turbine engines and is believed to offer valuable pollution control advantages relative to the conventional liquid-fuel-spray approach. It involves fuel prevaporization, premixing and lean combustion and may be applied to the design of combustors for aircraft, industrial or automotive powerplants. Two types of bluff-body flameholders, viz. porous-plate and drilled-plate, were evaluated for use as flame stabilizers within the combustor. Tests were conducted under sets of steady-state operational conditions corresponding, respectively, to applications in a low-pressure regenerative-cycle and high-pressure nonregenerative-cycle automobile gas turbine engines. The data acquired can be used to design gas turbine combustors having predicted performance characteristics which are better than those required to meet the most stringent automobile emissions regulations of the Federal “Clean Air Act.” Fuel prevaporization can be accomplished either externally, prior to admission into the engine airstream, or internally by the airstream itself. In support of the prevaporization concept, the feasibility of vaporizing No 2 fuel oil in a heat exchanger which is external to the engine was investigated. Tests conducted at representative operating conditions indicated that a deposit of 0.01 0-in. thickness was collected on the vaporizer wall after 50 hr of operation. A much shorter period of cleaning with hot air was sufficient to remove the deposit.

scholarly journals Dry Low Emissions Combustor Development

1998 ◽  
Author(s):  
Narendra D. Joshi ◽  
Hukam C. Mongia ◽  
Gary Leonard ◽  
Jim W. Stegmaier ◽  
Ed. C. Vickers
Keyword(s):  
Film Cooling ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Oxidation Reactions ◽  
Entire Family ◽  
Passive Devices ◽  
Key Characteristics ◽  
Lean Premixed ◽  
Fuel Staging ◽  
Full Power

Lower Emissions have become key characteristics of most new gas turbine engines over the last several years. The ‘lean premixed’ approach has been used in the development of the Dry Low Emissions (DLE) technology. The LM6000 and the LM2500 combustors employ a triple dome design with staging of fuel and air flows to achieve lean-premixed operation from light-off to full power. This technology permits the operator to run with reduced emissions of NOx as well as CO and UHC over a wide load setting. Emissions goals of 25 ppm have been successfully met at site rating conditions for the entire family of LM DLE products. The DLE combustor operates on the mid dome at light-off, the inner and the outer domes are brought on progressively, as the engine is loaded. The combustor utilizes a small quantity of air for dome and liner cooling as most of the combustor air is mixed with fuel in the premixers. Backside cooling enhancements permit the reduction of film cooling, which can cause quenching of CO oxidation reactions. Combustion acoustics are controlled by the use of passive devices on the exterior of the engine as well as by fuel staging within premixers and by the use of a control system which senses and alters the combustor operation to limit acoustics. The DLE technology meets the emissions and reliability needs of the industry with limited package modifications. This paper describes the DLE technology, developed to meet the needs of the industry. Critical design features including the Double Annular Counter-Rotating Swirler (DACRS) premixer, the triple annular dome design, the heat shield design and the staging sequence are discussed, in addition to the field experience gained on the LM2500 and LM6000 DLE models.

Dry Ultralow NOx “Green Thumb” Combustor for Allison’s 501-K Series Industrial Engines

1997 ◽  
Vol 119 (1) ◽  
pp. 93-101 ◽  
Author(s):  
R. Puri ◽  
D. M. Stansel ◽  
D. A. Smith ◽  
M. K. Razdan
Keyword(s):  
Fuel Injection ◽  
Combustion Efficiency ◽  
Mixing Efficiency ◽  
Oxides Of Nitrogen ◽  
Atmospheric Conditions ◽  
Swirl Angle ◽  
Lean Premixed ◽  
Air Mixing ◽  
Inlet Conditions ◽  
Engine Testing

This paper describes the progress made in developing an external ultralow oxides of nitrogen (NOx) “Green Thumb” combustor for the Allison Engine Company’s 501-K series engines. A lean premixed approach is being pursued to meet the emissions goals of 9 ppm NOx, 50 ppm carbon monoxide (CO), and 10 ppm unburned hydrocarbon (UHC). Several lean premixed (LPM) module configurations were identified computationally for the best NOx–CO trade-off by varying the location of fuel injection and the swirl angle of the module. These configurations were fabricated and screened under atmospheric conditions by direct visualization through a quartz liner; measurement of the stoichiometry at lean blow out (LBO); measurement of the fuel–air mixing efficiency at the module exit; and emissions measurements at the combustor exit, as well as velocity measurements. The influence of linear residence time on emissions was also examined. An LPM module featuring a radial inflow swirler demonstrated efficient fuel-air mixing and subsequent low NOx and CO production in extensive atmospheric bench and simulated engine testing. Measurements show the fuel concentration distribution at the module exit impacts the tradeoff between NOx and CO emissions. The effect of varying the swirl angle of the module also has a similar effect with the gains in NOx emissions reduction being traded for increased CO emissions. A uniform fuel-air mixture (±2.5 percent azimuthal variation) at the exit of the module yields low NOx (5–10 ppm) at inlet conditions of 1 MPa (~10 atm) and temperatures as high as 616 K (650°F). The combustion efficiency at these conditions was also good (>99.9 percent) with CO and UHC emissions below 76 ppm and 39 ppm, respectively. This LPM module was resistant to flashback, and stability was good as LBO was observed below φ = 0.50. Tests with multiple modules in a single liner indicate a strong intermodule interaction and show lower NOx and CO emissions. The close proximity of adjacent modules and lower confinement in the liner most likely reduces the size of the recirculation zone associated with each module, thereby reducing the NOx formed therein. The CO emissions are probably lowered due to the reduced cool liner surface area per module resulting when several modules feed into the same liner.

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