Factors Determining the Flame Configuration and Affecting Combustion Stability in Gas-Turbine Combustors

2020 ◽  
Vol 54 (4) ◽  
pp. 537-540
Author(s):  
L. A. Bulysova ◽  
A. G. Tumanovskii ◽  
M. N. Gutnik ◽  
V. D. Vasil’ev
Keyword(s):  
Gas Turbine ◽  
Combustion Stability ◽  
Gas Turbine Combustors

CFD Simulation of Noise in Gas Turbine Combustors by Means of Turbulence Refluctuation Method

2008 ◽  
Author(s):  
Stefano Tiribuzi
Keyword(s):  
Gas Turbine ◽  
Local Level ◽  
Computing Time ◽  
Combustion Noise ◽  
Qualitative Description ◽  
Combustion Stability ◽  
Medium Size ◽  
Pure Hydrogen ◽  
Computational Domain ◽  
Gas Turbine Combustors

The paper describes a numerical simulation methodology based on CFD for deriving and analyzing the spectral and spatial characteristics of combustion noise in industrial gas turbine combustors. ENEL is testing the combustion section of a medium size pure hydrogen-fed gas turbine, during which pressure fluctuation levels are also measured to asses the combustion stability. Pressure probes are located in colder zones only, but information on the fluctuations levels throughout the whole component are also desired. For this purpose, a simple empirical and, to the knowledge of the author, original method, based solely on CFD modelling, was developed for reproducing in a realistic way the spatial and transient characteristics of the acoustic flow field inside the combustor volumes. The method employs a sparse and persistent excitation on a wide frequency spectrum, by imposing a stochastic fluctuating component to the velocity computed on each grid node throughout the entire computational domain. The intensity of this additional component is proportional to the local level of the modelled turbulent velocity, so the method will be shortly designated as PRMT (Partial Refluctuation of Modelled Turbulence). This method requires that all the acoustically connected volumes be included in the computational domain and that transients be protracted for a time sufficient to provide meaningful spectral information. KIEN, an in-house low diffusive URANS code capable of simulating 3D reactive flows, was used. The adopted Very Rough Grid approach made it possible to protract the simulated transient for a long time, with an affordable computing time. Comparison with in-plant measured data shows that the refluctuation method provides a realistic qualitative description of the noise spectrum. The spatial distribution of computed acoustic field is also derived and analyzed.

scholarly journals Entropy and Vorticity Wave Generation in Realistic Gas Turbine Combustors

2019 ◽  
Vol 35 (4) ◽  
pp. 839-849 ◽  
Author(s):  
Bernhard Semlitsch ◽  
Tom Hynes ◽  
Ivan Langella ◽  
Nedunchezhian Swaminathan ◽  
Ann P. Dowling
Keyword(s):  
Gas Turbine ◽  
Wave Generation ◽  
Gas Turbine Combustors

Siemens SGT-800 Industrial Gas Turbine Enhanced to 50MW: Combustor Design Modifications, Validation and Operation Experience

2013 ◽  
Author(s):  
Daniel Lörstad ◽  
Annika Lindholm ◽  
Jan Pettersson ◽  
Mats Björkman ◽  
Ingvar Hultmark
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Cooling System ◽  
Good Condition ◽  
Combined Cycle ◽  
Combustion Stability ◽  
Combustion System ◽  
Design Work ◽  
Engine Operation ◽  
Cooling Air

Siemens Oil & Gas introduced an enhanced SGT-800 gas turbine during 2010. The new power rating is 50.5MW at a 38.3% electrical efficiency in simple cycle (ISO) and best in class combined-cycle performance of more than 55%, for improved fuel flexibility at low emissions. The updated components in the gas turbine are interchangeable from the existing 47MW rating. The increased power and improved efficiency are mainly obtained by improved compressor airfoil profiles and improved turbine aerodynamics and cooling air layout. The current paper is focused on the design modifications of the combustor parts and the combustion validation and operation experience. The serial cooling system of the annular combustion chamber is improved using aerodynamically shaped liner cooling air inlet and reduced liner rib height to minimize the pressure drop and optimize the cooling layout to improve the life due to engine operation hours. The cold parts of the combustion chamber were redesigned using cast cooling struts where the variable thickness was optimized to maximize the cycle life. Due to fewer thicker vanes of the turbine stage #1, the combustor-turbine interface is accordingly updated to maintain the life requirements due to the upstream effect of the stronger pressure gradient. Minor burner tuning is used which in combination with the previously introduced combustor passive damping results in low emissions for >50% load, which is insensitive to ambient conditions. The combustion system has shown excellent combustion stability properties, such as to rapid load changes and large flame temperature range at high loads, which leads to the possibility of single digit Dry Low Emission (DLE) NOx. The combustion system has also shown insensitivity to fuels of large content of hydrogen, different hydrocarbons, inerts and CO. Also DLE liquid operation shows low emissions for 50–100% load. The first SGT-800 with 50.5MW rating was successfully tested during the Spring 2010 and the expected performance figures were confirmed. The fleet leader has, up to January 2013, accumulated >16000 Equivalent Operation Hours (EOH) and a planned follow up inspection made after 10000 EOH by boroscope of the hot section showed that the combustor was in good condition. This paper presents some details of the design work carried out during the development of the combustor design enhancement and the combustion operation experience from the first units.

Extension of the Combustion Stability Range in Dry Low NOx Lean Premixed Gas Turbine Combustor Using a Fuel Rich Annular Pilot Burner

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
L. Rosentsvit ◽  
Y. Levy ◽  
V. Erenburg ◽  
V. Sherbaum ◽  
V. Ovcharenko ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Combustion Zone ◽  
Combustion Instability ◽  
Experimental Results ◽  
Nox Emission ◽  
Combustion Stability ◽  
Stability Range ◽  
Numerical Effort ◽  
Lean Premixed ◽  
Pilot Burner

The present work is concerned with improving combustion stability in lean premixed (LP) gas turbine combustors by injecting free radicals into the combustion zone. The work is a joint experimental and numerical effort aimed at investigating the feasibility of incorporating a circumferential pilot combustor, which operates under rich conditions and directs its radicals enriched exhaust gases into the main combustion zone as the means for stabilization. The investigation includes the development of a chemical reactors network (CRN) model that is based on perfectly stirred reactors modules and on preliminary CFD analysis as well as on testing the method on an experimental model under laboratory conditions. The study is based on the hypothesis that under lean combustion conditions, combustion instability is linked to local extinctions of the flame and consequently, there is a direct correlation between the limiting conditions affecting combustion instability and the lean blowout (LBO) limit of the flame. The experimental results demonstrated the potential reduction of the combustion chamber's LBO limit while maintaining overall NOx emission concentration values within the typical range of low NOx burners and its delicate dependence on the equivalence ratio of the ring pilot flame. A similar result was revealed through the developed CHEMKIN-PRO CRN model that was applied to find the LBO limits of the combined pilot burner and main combustor system, while monitoring the associated emissions. Hence, both the CRN model, and the experimental results, indicate that the radicals enriched ring jet is effective at stabilizing the LP flame, while keeping the NOx emission level within the characteristic range of low NOx combustors.

Study on the Use of HiCOP Fuel for Gas Turbine Combustors

2017 ◽  
Author(s):  
Hitoshi Fujiwara ◽  
Keiichi Okai ◽  
Mitsumasa Makida ◽  
Kazuo Shimodaira ◽  
Takuya Mizuno ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbine Combustors

A Critical Review of NOx Correlations for Gas Turbine Combustors

1975 ◽  
Author(s):  
D. A. Sullivan ◽  
P. A. Mas
Keyword(s):  
Experimental Data ◽  
Data Base ◽  
Gas Turbine ◽  
Critical Review ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Empirical Correlations ◽  
Gas Turbine Combustors ◽  
Semi Empirical ◽  
Adequate Data

The effect of inlet temperature, pressure, air flowrate and fuel-to-air ratio on NOx emissions from gas turbine combustors has received considerable attention in recent years. A number of semi-empirical and empirical correlations relating these variables to NOx emissions have appeared in the literature. They differ both in fundamental assumptions and in their predictions. In the present work, these simple NOx correlations are compared to each other and to experimental data. A review of existing experimental data shows that an adequate data base does not exist to evaluate properly the various NOx correlations. Recommendations are proposed to resolve this problem in the future.

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