A Simple Gas Turbine Combustor NOx Correlation Including the Effect of Vitiated Air

1977 ◽  
Vol 99 (2) ◽  
pp. 145-152 ◽  
Author(s):  
D. A. Sullivan
Keyword(s):  
Gas Turbines ◽  
Laboratory Tests ◽  
Nox Reduction ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Gaseous Fuels ◽  
Fuel Flow ◽  
In Series ◽  
Data Points ◽  
Regenerative Cycle

A set of parametric laboratory tests are used to develop a simple NOx correlation. The correlation is then compared with over 100 data points from various gas turbines operating on liquid and gaseous fuels. The correlation agrees well with constant speed simple cycle and regenerative cycle NOx data. The effect of vitiated air on NOx emissions is also determined from full scale laboratory tests and machine data. The NOx correlation with vitiated air is used to demonstrate the NOx emissions from two combustors operated in series with a variable fuel flow split between them. The nonlinear effect of fuel-to-air ratio on NOx production is shown to be responsible for the NOx reduction which occurs when two combustors are operated in series as opposed to single combustor operation.

A NOx Reduction Project for a GT11 Type Gas Turbine

2005 ◽  
Author(s):  
Lars O. Nord ◽  
David R. Schoemaker ◽  
Helmer G. Andersen
Keyword(s):  
Power Plant ◽  
Distribution System ◽  
Gas Turbines ◽  
Nox Reduction ◽  
Measurement Data ◽  
Combustion Stability ◽  
Study Phase ◽  
Nox Emissions ◽  
Ambient Conditions ◽  
Exhaust Temperature

A study was initiated to investigate the possibility of significantly reducing the NOx emissions at a power plant utilizing, among other manufacturers, ALSTOM GT11 type gas turbines. This study is limited to one of the GT11 type gas turbines on the site. After the initial study phase, the project moved on to a mechanical implementation stage, followed by thorough testing and tuning. The NOx emissions were to be reduced at all ambient conditions, but particularly at cold conditions (below 0°C) where a NOx reduction of more than 70% was the goal. The geographical location of the power plant means cold ambient conditions for a large part of the year. The mechanical modifications included the addition of Helmholtz damper capacity with an approximately 30% increase in volume for passive thermo-acoustic instability control, significant piping changes to the fuel distribution system in order to change the burner configuration, and installation of manual valves for throttling of the fuel gas to individual burners. Subsequent to the mechanical modifications, significant time was spent on testing and tuning of the unit to achieve the wanted NOx emissions throughout a major part of the load range. The tuning was, in addition to the main focus of the NOx reduction, also focused on exhaust temperature spread, combustion stability, CO emissions, as well as other parameters. The measurement data was acquired through a combination of existing unit instrumentation and specific instrumentation added to aid in the tuning effort. The existing instrumentation readings were polled from the control system. The majority of the added instrumentation was acquired via the FieldPoint system from National Instruments. The ALSTOM AMODIS plant-monitoring system was used for acquisition and analysis of all the data from the various sources. The project was, in the end, a success with low NOx emissions at part load and full load. As a final stage of the project, the CO emissions were also optimized resulting in a nice compromise between the important parameters monitored, namely NOx emissions, CO emissions, combustion stability, and exhaust temperature distribution.

scholarly journals The Effect of Discrete Pilot Hydrogen Dopant Injection on the Lean Blowout Performance of a Model Gas Turbine Combustor

1999 ◽  
Author(s):  
Oanh Nguyen ◽  
Scott Samuelsen
Keyword(s):  
Gas Turbine ◽  
Atmospheric Pressure ◽  
Gas Turbines ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Lean Blowout ◽  
Lean Combustion ◽  
Attractive Option ◽  
Overall Performance ◽  
Model Gas Turbine Combustor

In view of increasingly stringent NOx emissions regulations on stationary gas turbines, lean combustion offers an attractive option to reduce reaction temperatures and thereby decrease NOx production. Under lean operation, however, the reaction is vulnerable to blowout. It is herein postulated that pilot hydrogen dopant injection, discretely located, can enhance the lean blowout performance without sacrificing overall performance. The present study addresses this hypothesis in a research combustor assembly, operated at atmospheric pressure, and fired on natural gas using rapid mixing injection, typical of commercial units. Five hydrogen injector scenarios are investigated. The results show that (1) pilot hydrogen dopant injection, discretely located, leads to improved lean blowout performance and (2) the location of discrete injection has a significant impact on the effectiveness of the doping strategy.

Kinetics Modeling on NOx Emissions of a Syngas Turbine Combustor Using RQL Combustion Method

2019 ◽  
Author(s):  
Haoyang Liu ◽  
Wenkai Qian ◽  
Min Zhu ◽  
Suhui Li
Keyword(s):  
Gas Turbine ◽  
Residence Time ◽  
Air Flow ◽  
Nox Reduction ◽  
Outlet Temperature ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Kinetics Modeling ◽  
The Rich ◽  
Nox Control

Abstract To avoid flashback issues of the high-H2 syngas fuel, current syngas turbines usually use non-premixed combustors, which have high NOx emissions. A promising solution to this dilemma is RQL (rich-burn, quick-mix, lean-burn) combustion, which not only reduces NOx emissions, but also mitigates flashback. This paper presents a kinetics modeling study on NOx emissions of a syngas-fueled gas turbine combustor using RQL architecture. The combustor was simulated with a chemical reactor network model in CHEMKIN-PRO software. The combustion and NOx formation reactions were modeled using a detailed kinetics mechanism that was developed for syngas. Impacts of combustor design/operating parameters on NOx emissions were systematically investigated, including combustor outlet temperature, rich/lean air flow split and residence time split. The mixing effects in both the rich-burn zone and the quick-mix zone were also investigated. Results show that for an RQL combustor, the NOx emissions initially decrease and then increase with combustor outlet temperature. The leading parameters for NOx control are temperature-dependent. At typical modern gas turbine combustor operating temperatures (e.g., < 1890 K), the air flow split is the most effective parameter for NOx control, followed by the mixing at the rich-burn zone. However, as the combustor outlet temperature increases, the impacts of air flow split and mixing in the rich-burn zone on NOx reduction become less pronounced, whereas both the residence time split and the mixing in the quick-mix zone become important.

Development of a Small-Scale Catalytic Gas Turbine Combustor

1982 ◽  
Vol 104 (1) ◽  
pp. 52-57 ◽  
Author(s):  
S. J. Anderson ◽  
M. A. Friedman ◽  
W. V. Krill ◽  
J. P. Kesselring
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Efficiency ◽  
Small Scale ◽  
Time Interval ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Opposed Jet

Catalytically supported thermal combustion can provide low NOx emissions with gaseous and distillate fuels while maintaining high combustion efficiency. For stationary gas turbines, catalytic combustion may be the only emerging technology that can cost effectively meet recent federal regulations for NOx emissions. Under EPA sponsorship, a small-scale, catalytic gas turbine combustor was developed to evaluate transient and steady state combustor performance. The combustor consisted of a multiple air-atomizing fuel injector, an opposed jet igniter, and a graded-cell monolithic reactor. System startup, including opposed jet ignition and catalyst stabilization, was achieved in 250 seconds. This time interval is comparable to conventional gas turbines. Steady state operation was performed at 0.505 MPa (5 atmospheres) pressure and 15.3 m/s (50 ft/s) reference velocities. Thermal NOx emissions were measured below 10 ppmv, while fuel NOx conversion ranged from 75 to 95 percent. At catalyst bed temperatures greater than 1422K (2100°F), total CO and UHC emissions were less than 50 ppmv indicating combustion efficiency greater than 99.9 percent. Compared with conventional gas turbine combustors, the catalytic reactor operates only within a relatively narrow range of fuel/air ratios. As a result, modified combustor air distribution or fuel staging will be required to achieve the wide turndown required in large stationary systems.

scholarly journals Evaluation of a Premixed, Prevaporized Gas Turbine Combustor for No. 2 Distillate

1977 ◽  
Author(s):  
D. P. Teixeira ◽  
D. J. White ◽  
M. E. Ward
Keyword(s):  
Heat Capacity ◽  
Gas Turbine ◽  
Air Temperature ◽  
Gas Turbines ◽  
Electric Utility ◽  
Nox Emissions ◽  
Pressure Condition ◽  
Control Potential ◽  
Gas Turbine Combustor ◽  
Current Generation

Results of a series of tests on a prevaporized, premixed combustor to evaluate its emissions control potential while operating on No. 2 distillate oil are presented. The concept utilized the heat capacity of the combustor inlet air to absorb the heat of vaporization of the fuel. Tests were conducted at combustor inlet temperatures and pressures characteristic of current generation electric utility gas turbines (345 C and 10 atm). NOx emissions in excess of proposed EPA gas turbine standards (75 ppm at 15 percent O) were observed at the 10 atm pressure condition and are believed to be the result of incomplete evaporation of the fuel Attempts to increase vaporization rates by increasing inlet air temperature were limited by autoignition of the mixture in the fuel preparation ports.

scholarly journals Influence of Residence Time on Fuel Spray Sauter Mean Diameter (SMD) and Emissions Using Biodiesel and its Blends in a Low NOx Gas Turbine Combustor

2016 ◽  
Author(s):  
Mohamed A. Altaher ◽  
Hu Li ◽  
Gordon E. Andrews
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Fuel Spray ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Gaseous Emissions ◽  
Low Carbon ◽  
Sauter Mean Diameter ◽  
Gas Turbine Combustor ◽  
Mean Diameter

Biodiesels have advantages of low carbon footprint, reduced toxic emissions, improved energy supply security and sustainability and therefore attracted attentions in both industrial and aero gas turbines sectors. Industrial gas turbine applications are more practical biodiesels due to low temperature waxing and flow problems at altitude for aero gas turbine applications. This paper investigated the use of biodiesels in a low NOx radial swirler, as used in some industrial low NOx gas turbines. A waste cooking oil derived methyl ester biodiesel (WME) was tested on a radial swirler industrial low NOx gas turbine combustor under atmospheric pressure, 600K air inlet temperature and reference Mach number of 0.017&0.023. The pure WME, its blends with kerosene (B20 and B50) and pure kerosene were tested for gaseous emissions and lean extinction as a function of equivalence ratio for both Mach numbers. Sauter Mean Diameter (SMD) of the fuel spray droplets was calculated. The results showed that the WME and its blends had lower CO, UHC emissions and higher NOx emissions than the kerosene. The weak extinction limits were determined for all fuels and B100 has the lowest value. The higher air velocity (at Mach = 0.023) resulted in smaller SMDs which improved the mixing and atomizing of fuels and thus led to reductions in NOx emissions.

scholarly journals A NOx Correlation Method for Gas Turbine Combustors Based on NOx Formation Assumptions

1974 ◽  
Author(s):  
Géza Vermes
Keyword(s):  
Gas Turbine ◽  
A Priori ◽  
Combustion Process ◽  
Correlation Method ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Nox Formation ◽  
Simple Method ◽  
Fuel Flow

Based on a simplified description of the combustion process in the primary zone of a can type gas turbine combustor, a generalized NOx versus fuel flow relationship is proposed. Using this relationship and considerations based on chemical kinetics, the effect of combustor inlet pressure, inlet temperature and air residence time on NOx formation is investigated in industrial and automotive type combustion chambers. Data reported in the literature and original test work is cited to substantiate the validity of the assumptions. Based on the findings, a simple method is presented to predict NOx emissions of a gas turbine combustor under conditions which differ substantially from those of the test run. The assumptions may be used to assemble a model for a priori prediction of NOx emissions in a given combustion geometry.

scholarly journals The Capability of Different Semianalytical Equations for Estimation of NOx Emissions of Gas Turbines

1994 ◽  
Author(s):  
T. Becker ◽  
M. A. Perkavec
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Coke Oven ◽  
Steam Injection ◽  
Nox Emissions ◽  
Operational Conditions ◽  
Inlet Conditions ◽  
The One ◽  
Turbine Design ◽  
Regenerative Cycle

The NOx emissions of gas turbines are depending on different influences. On the one side there are the effects fixed by the gas turbine design and on the other side the ambient effects, the fuel properties and the operational conditions. Because the NOx emissions are difficult to calculate by chemical reactions and flow calculations, some investigators developed semianalytical equations, which in their opinion contained the most important influencing factors together with some tuning factors for the actual gas turbine design and application. This paper shows the capability of those procedures, including a new one. It compares the calculated NOx emission with measured data. The comparisons were made for one gas turbine fired with different fuels (natural gas, propane, butane, coke oven gas), as well as for different combustor inlet conditions in case of simple and regenerative cycle operation. Reference is made also for some other gas turbine models. Also full and part load operation as well as the steam injection effects are included.

Adaptive and Efficient Ammonia Storage Distribution Control for a Two-Catalyst Selective Catalytic Reduction System

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Ming-Feng Hsieh ◽  
Junmin Wang
Keyword(s):  
Catalytic Reduction ◽  
Nox Reduction ◽  
Injection Rate ◽  
Nox Emissions ◽  
System A ◽  
Ammonia Slip ◽  
Ammonia Storage ◽  
In Series ◽  
Storage Distribution ◽  
Scr System

This paper presents an adaptive urea-SCR dosing control design for a two-catalyst SCR system. A novel SCR ammonia storage distribution control (ASDC) approach aiming to simultaneously increase the SCR NOx conversion efficiency and reduce the tailpipe ammonia slip was proposed and experimentally validated. Based on the insight into SCR operational principles, a high ammonia storage level at the upstream part of the catalyst can generally yield a higher NOx reduction efficiency while a low ammonia storage level at the downstream part of the catalyst can reduce the undesired tailpipe ammonia slip. To achieve such an ammonia storage distribution control, a two-catalyst (in series) SCR system with NOx and NH3 sensors was devised. Grounded in a newly developed SCR control-oriented model, an adaptive (with respect to the SCR ammonia storage capacity) controller was designed to control the urea injection rate for achieving different ammonia storages in the two catalysts. Experimental data from a US06 test cycle conducted on a medium-duty Diesel engine system showed that, with the similar total engine-out NOx emissions and NH3 (AdBlue) consumptions, the proposed ASDC strategy simultaneously reduced the tailpipe NOx emissions by 57% and the ammonia slip by 74% in comparison to those from a conventional controller.

scholarly journals Reduction of NOx Emission from Gas TURBINE COMBUSTOR Applying Fuel-Staged Combustion

2008 ◽  
Vol 2 (1) ◽  
pp. 61
Author(s):  
Mohammad Nazri ◽  
Mohd. Jaafar
Keyword(s):  
Carbon Monoxide ◽  
Gas Turbine ◽  
Main Stage ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Inside Diameter ◽  
Fuel Staging ◽  
In Series ◽  
The Rich

A two-stage lean/lean gas turbine combustor was developed with low NOx characteristics in each stage using a small radial swirler of 40-mm outlet diameter in the pilot stage. Both flame tubes were arranged in series with the smaller combustor (76 mm inside diameter) as the pilot stage and the larger combustor (140 mm inside diameter) as the main stage. The pilot stage was fuelled via vane passage fuel injector, while the main stage was fuelled around the wall of the exit plane of the pilot stage, using wall fuel injectors. Low NOx emissions were obtained when using fuel staging for methane fuel, as low as 6 ppm. A NO. reduction of more than 40 % was obtained at equivalence ratio of near 0.7, when using fuel staging compared to the non-fuel-staging test. Tests were conducted using methane as fuel. This was achieved at very small increase in carbon monoxide emissions especially near the rich region and with almost no increase at all in the unburned hydrocarbon emissions at the same equivalence ratio.Keywords: NOx emissions, fuel staging, carbon monoxide, swirler.

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