Sensors for measuring primary zone equivalence ratio in gas turbine combustors

1999 ◽  
Author(s):  
Ramarao V. Bandaru ◽  
Sean Miller ◽  
Jong-Guen Lee ◽  
Domenic A. Santavicca
Keyword(s):  
Gas Turbine ◽  
Equivalence Ratio ◽  
Gas Turbine Combustors ◽  
Primary Zone

scholarly journals Smoke Characteristics of Distillate and Residual Fuel Burning in Gas Turbine Combustors

1980 ◽  
Author(s):  
T. M. Liu ◽  
R. M. Washam
Keyword(s):  
Trace Metals ◽  
Chemical Analysis ◽  
Gas Turbine ◽  
Equivalence Ratio ◽  
Appreciable Amount ◽  
High Concentration ◽  
Gas Turbine Combustors ◽  
Fuel Burning ◽  
Distillate Fuel

During the development of a rich-lean staged dry low NOx combustor, the conventional trend of increasing smoke with increasing operating equivalence ratio was found when tests were run with distillate fuel (%H = 13.0). However, when tests were run with residual fuel (%H = 11.4), the trend was reversed. In addition, when the same combustor was run with blends of distillate fuel and residual fuel, a drastic improvement of smoke was observed when only 6 percent of residual fuel was mixed with distillate fuel, and for any blending of more than 10 percent of residual fuel the combustor was practically smoke free. A chemical analysis of fuel samples revealed an appreciable amount of trace metals in the residual fuel, giving rise to the suspicion that the smoke reduction may have been due in part to these trace metals. Of these elements found, vanadium is believed to be the most likely to cause smoke reduction because of its relatively high concentration.

The Influence of Film Cooling on Emissions for a Low NOx Radial Swirler Gas Turbine Combustor

2001 ◽  
Author(s):  
G. E. Andrews ◽  
M. N. Kim
Keyword(s):  
Mach Number ◽  
Gas Turbine ◽  
Flow Rate ◽  
Film Cooling ◽  
Equivalence Ratio ◽  
Air Flow ◽  
Gas Turbine Combustor ◽  
Cooling Flow ◽  
Full Coverage ◽  
Primary Zone

An experimental investigation was undertaken of the influence on emissions of full coverage discrete hole film cooling of a lean low NOx radial swirler natural gas combustor. The combustor used radial swirler vane passage fuel injection on the centre of the vane passage inlet. The test configuration was similar to that used in the Alstom Power Tornado and related family of low NOx gas turbines. The test conditions were simulated at atmospheric pressure at the flow condition of lean low NOx gas turbine primary zones. The tests were carried out at an isothermal flow Mach number of 0.03, which represents 60% of industrial gas turbine combustor airflow through the swirl primary zone. The effusion film cooling used was Rolls-Royce Transply, which has efficient internal cooling of the wall as well as full coverage discrete hole film cooling. Film cooling levels of 0, 16 and 40% of the primary zone airflow were investigated for a fixed total primary zone air flow and reference Mach number of 0.03. The results showed that there was a major increase in the NOx emissions for 740K inlet temperature and 0.45 overall equivalence ratio from 6ppm at zero film cooling air flow to 32ppm at 40% coolant flow rate. CO emissions increased from 25ppm to 75ppm for the same increase in film cooling flow rate. It was shown that the main effect was the creation of a richer inner swirler combustion with a surrounding film cooling flow that did not mix well with the central swirling combustion. The increase in NOx and CO could be predicted on the basis of the central swirl flow equivalence ratio.

Combustion Air Jet Influence on Primary Zone Characteristics for Gas-Turbine Combustors

2002 ◽  
Vol 18 (2) ◽  
pp. 407-416 ◽  
Author(s):  
S. Gogineni ◽  
D. Shouse ◽  
C. Frayne ◽  
J. Stutrud ◽  
G. Sturgess
Keyword(s):  
Gas Turbine ◽  
Gas Turbine Combustors ◽  
Air Jet ◽  
Primary Zone

Characteristic Time Model Correlation of NOx Emissions From Lean Premixed Combustors

1995 ◽  
Author(s):  
Donald M. Newburry ◽  
Arthur M. Mellor
Keyword(s):  
Gas Turbine ◽  
Diffusion Flame ◽  
Characteristic Time ◽  
Equivalence Ratio ◽  
Nox Emissions ◽  
Time Model ◽  
New Model ◽  
Gas Turbine Combustors ◽  
Ratio Data ◽  
Lean Premixed

The semi–empirical characteristic time model (CTM) has been used previously to correlate and predict emissions data from conventional diffusion flame, gas turbine combustors. The form of the model equation was derived for NOx emissions from laboratory flameholders and then extended to conventional gas turbine combustors. The model relates emissions to the characteristic times of distinct combustion subprocesses, with empirically determined model constants. In this paper, a new model is developed for lean premixed (LP) NOx emissions from a perforated plate flameholder combustor burning propane fuel. Several modifications to the diffusion flame CTM were required, including a new activation energy and a more complicated dependence on combustor pressure. Appropriate model constants were determined from the data, and the correlation results are reasonable. An attempt was made to validate the new model with LP NOx data for a different but geometrically similar flameholder operating at lower pressures. The predictions are good for the low equivalence ratio data. However, a systematic error in the reported equivalence ratios may be adversely affecting the predictions of the higher equivalence ratio data through the calculated adiabatic flame temperature.

Implication of Different Fuel Injector Configurations for Hydrogen Fuelled Micromix Combustors

2011 ◽  
Author(s):  
Bhupendra Khandelwal ◽  
Yingchun Li ◽  
Priyadarshini Murthy ◽  
Vishal Sethi ◽  
Riti Singh
Keyword(s):  
Gas Turbine ◽  
Thermal Energy ◽  
Combustion Zone ◽  
Equivalence Ratio ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Gas Turbine Combustors ◽  
The Impact

A design of a hydrogen fuelled micromix concept based combustor is proposed in this paper. The proposed micromix concept based combustor yields improved mixing, which leads to wider flammability range of the hydrogen-air flames compared to conventional kerosene and micromix concept based combustors. This improved mixing allows the combustion zone to operate at a much lower equivalence ratio than the conventional kerosene based and micromix concept based combustors considered in this study. Furthermore, when burning hydrogen the thermal energy radiated to the surroundings is lower (as the result of using lower equivalence ratio) than that of kerosene, consequently resulting in an increased liner life and lower cooling requirement. The aim of this paper is to highlight the impact of using hydrogen as a fuel in gas turbine combustors. It is perceived that this new micromix concept based combustor would also help in achieving low emissions and better performance. Possibilities for lowering NOx emissions when using hydrogen as a fuel in new designs of micromix combustor are also discussed.

Prediction of lean blowout performance on variation of combustor inlet area ratio for micro gas turbine combustor

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kirubakaran V. ◽  
Naren Shankar R.
Keyword(s):  
Gas Turbine ◽  
Mass Flow ◽  
Equivalence Ratio ◽  
Area Ratio ◽  
Gas Temperature ◽  
Gas Turbine Combustor ◽  
Content Type ◽  
Lean Blowout ◽  
Micro Gas Turbine ◽  
Primary Zone

Purpose This paper aims to predict the effect of combustor inlet area ratio (CIAR) on the lean blowout limit (LBO) of a swirl stabilized can-type micro gas turbine combustor having a thermal capacity of 3 kW. Design/methodology/approach The blowout limits of the combustor were predicted predominantly from numerical simulations by using the average exit gas temperature (AEGT) method. In this method, the blowout limit is determined from characteristics of the average exit gas temperature of the combustion products for varying equivalence. The CIAR value considered in this study ranges from 0.2 to 0.4 and combustor inlet velocities range from 1.70 to 6.80 m/s. Findings The LBO equivalence ratio decreases gradually with an increase in inlet velocity. On the other hand, the LBO equivalence ratio decreases significantly especially at low inlet velocities with a decrease in CIAR. These results were backed by experimental results for a case of CIAR equal to 0.2. Practical implications Gas turbine combustors are vulnerable to operate on lean equivalence ratios at cruise flight to avoid high thermal stresses. A flame blowout is the main issue faced in lean operations. Based on literature and studies, the combustor lean blowout performance significantly depends on the primary zone mass flow rate. By incorporating variable area snout in the combustor will alter the primary zone mass flow rates by which the combustor will experience extended lean blowout limit characteristics. Originality/value This is a first effort to predict the lean blowout performance on the variation of combustor inlet area ratio on gas turbine combustor. This would help to extend the flame stability region for the gas turbine combustor.

scholarly journals Combustion of Liquid Fuels in the Well Stirred Reactor

1996 ◽  
Author(s):  
J. Zelina ◽  
J. W. Blust ◽  
D. R. Ballal
Keyword(s):  
Gas Turbine ◽  
Equivalence Ratio ◽  
Equilibrium Concentration ◽  
Liquid Fuels ◽  
Jet Fuels ◽  
Stirred Reactor ◽  
Primary Zone ◽  
Appreciable Increase ◽  
Performance And Emissions ◽  
Industrial Gas Turbine

The design and development of low-emissions, lean premixed aero, or industrial gas turbine combustors is very challenging because of a need to satisfy conflicting requirements of combustion performance and emissions. A toroidal well stirred reactor (WSR) provides a laboratory idealization of an efficient, highly compact primary zone of a gas turbine combustor and facilitates the study of combustion and emissions. The WSR was used to study emissions from heptane and JP-7 fuels. It was found that the measured concentrations of CO2 and O2 agreed closely with the predictions of the equilibrium concentration. CO emissions for ϕ > 0.77 followed the equilibrium predictions reasonably well. But for ϕ < 0.77, the measured CO values were much higher than the equilibrium values. NOx emission increased as equivalence ratio approaches unity. Tests conducted at a constant equivalence ratio and residence time demonstrated an appreciable increase in CO and a modest increase in NOx with an increase in the (C/H) mole ratio. Therefore, a combustor designer should be concerned that jet fuels with lower hydrogen content will produce increased emissions of gaseous pollutants.

An Integrated Design Approach for Micro Gas Turbine Combustors: Preliminary 0-D and Simplified CFD Based Optimization

2006 ◽  
Author(s):  
Luca Fuligno ◽  
Diego Micheli ◽  
Carlo Poloni
Keyword(s):  
Gas Turbine ◽  
Integrated Design ◽  
Baseline Design ◽  
Pressure Losses ◽  
Gas Turbine Combustors ◽  
Novel Approach ◽  
Primary Zone ◽  
Lean Premixed ◽  
Integrated Design Process ◽  
Cfd Analyses

The present work presents a novel approach for the optimised design of small gas turbine combustors, that integrates a 0-D code. CFD analyses and an advanced game theory multi-objective optimization algorithm. The output of the 0-D code is a baseline design of the combustor, given the required fuel characteristics, the basic geometry (tubular or annular) and the combustion concept (i.e. lean premixed primary zone or diffusive processes). For the optimization of the baseline design a parametric CAD/mesher model is then defined and submitted to a CFD code. Free parameters of the optimization process are position and size of the liner holes arrays, their total area and the shape of the exit duct, while different objectives are the minimisation of NOx emissions, pressure losses and combustor exit Pattern Factor. As a first demonstrative example, the integrated design process was applied to a tubular combustion chamber with a lean premixed primary zone for a recuperative methane-fuelled small gas turbine of the 100 kW class.

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