Modeling of pollutant emission from the combustion chamber of a stationary gas turbine drive

2014 ◽  
Vol 57 (3) ◽  
pp. 283-290
Author(s):  
I. A. Zaev ◽  
B. V. Potapkin ◽  
S. A. Fedorov ◽  
V. V. Kuprik
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Pollutant Emission ◽  
Turbine Drive

Further Studies of Alternative Jet Fuels

2009 ◽  
Author(s):  
Christopher J. Mordaunt ◽  
Seong-Young Lee ◽  
Vickey B. Kalaskar ◽  
Amy Mensch ◽  
Robert J. Santoro ◽  
...  
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Fuel Injection ◽  
Combustion Instability ◽  
Combustion Efficiency ◽  
Liquid Fuels ◽  
Pollutant Emission ◽  
Fischer Tropsch ◽  
Mixing Processes

Future gas turbine technology may require that liquid fuels play an additional role as a coolant over a wide range of combustion-chamber operating conditions. Additionally, in order to satisfy greater efficiency and performance goals, gas turbine operating temperatures and pressures are steadily increasing. Given the desire to reduce dependence on foreign fuels and that current hydrocarbon fuels, such as JP-8, are prone to thermal or catalytic decomposition at such elevated conditions, there is great interest in utilizing alternatively-derived liquid fuels. The successful development of a versatile, multiple-use fuel must achieve the desired operational characteristics of high combustion efficiency, excellent combustion stability, acceptable pollutant emission levels, and compatibility with current engine seals. Combustion instability represents a critical area of concern for future gas turbine engines that may burn alternative fuels. Combustion instability is characterized by large, unsteady combustion-chamber pressure oscillations which occur at the characteristic frequencies associated with the acoustic modes of the combustor. The occurrence of combustion-driven instabilities is closely tied to the details of the injection and fuel-air mixing processes, the heat release characteristics, and the degree to which heat release rate couples with the acoustics of the combustor. Additionally, the efficiency and emissions characteristics are also largely determined by the fuel injection, atomization, and mixing processes associated with combustion. As fuel properties and composition vary, effects on combustion efficiency and emissions, especially the formation of nitrogen oxides (NOx) and soot, can be expected. Therefore, changes in these processes attributed to differing fuel properties can have a dramatic affect on the combustion characteristics and require careful consideration through a well-coordinated combustion research program. The current study investigates whether a coal-based aviation fuel, JP-900, which has the required thermal stability attributes, also satisfies the engine combustion requirements. Additionally, a Fischer-Tropsch fuel and a volumetric 50/50 blend of JP-8 and the Fischer-Tropsch fuel are studied. Previous studies of coal-based fuels have shown that soot production can be a significant problem due to the higher aromatic content than found in conventional fuels. However, improvements in the fuel refinement processes have helped reduce this problem. Experiments included in this current research effort involve studying the combustion instability patterns, the pollutant emission levels, and sooting propensity of coal-based and Fischer-Tropsch fuels as compared to JP-8. The experimental setup consists of an optically-accessible model gas turbine dump combustor, with provisions for laser extinction measurements, which utilizes a Delavan hollow-cone pressure atomizer for fuel injection.

Performance and Emission Levels in Gas Turbine Plants

1994 ◽  
Vol 116 (1) ◽  
pp. 53-62 ◽  
Author(s):  
F. Bozza ◽  
R. Tuccillo ◽  
G. Fontana
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Carbon Dioxide Emissions ◽  
Coal Gasification ◽  
Pressure Ratio ◽  
Nox Reduction ◽  
Steam Injection ◽  
Pollutant Emission ◽  
Accurate Analysis ◽  
Performance And Emission

The rise in gas turbine combustion chamber temperatures requires optimal choices to be made with regard not only to performance parameters but also with a view to resolving pollutant emission problems. For this reason, the authors have set up a gas turbine cycle model, which performs an accurate analysis of several processes, in terms of operating fluid chemical and thermodynamic properties. The model also enables prediction of NOx formation based upon chemical kinetics and is able to relate the amount of pollutants to a number of operating parameters (e.g., cycle pressure ratio, fuel-to-air equivalence ratio, residence time in combustion chamber, etc.). It can also predict the effect of most usual NOx reduction systems, such as water or steam injection. A comparison of several possible choices for the gas and combined cycles is then presented, in terms of thermodynamic performance (e.g., first and second law analysis) and nitric and carbon dioxide emissions. In order to find the best compromise between performance improvement and limitation of pollutant emission, enhanced gas cycles are also considered, such as STIG or intercooled-reheat cycles. Examples also refer to medium or low Btu gases, obtained from coal gasification, in order to show not only the possible advantages in terms of thermal NOx reduction, but also the significant amounts of “fuel NOx” that can arise from ammonia contained in the fuel.

scholarly journals Effects of Swirling Strength of the Premixed Gas Flow on Pollutant Emission in a Heavy-Duty Gas Turbine

2019 ◽  
Vol 118 ◽  
pp. 04038
Author(s):  
Huanhuan Gao ◽  
Zaiguo Fu ◽  
Zhuoxiong Zeng ◽  
Jiang Liu ◽  
Peifen Weng
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Flow ◽  
Swirling Flow ◽  
Combustion Process ◽  
Side Wall ◽  
Pollutant Emission ◽  
Heavy Duty ◽  
Average Mass ◽  
Heavy Duty Gas Turbine

The combustion process and pollutant emission of an annular combustion chamber for a heavy-duty gas turbine were investigated by numerical method. The realizable k-ε model and finite rate/eddy dissipation model were adopted for calculations of turbulence and combustion. The effects of different swirling numbers of the double-swirler inlet on the temperature distribution and the thermal NOx formation in the combustion chamber were analyzed. The results show that the change of the swirling number of the outer swirling flow has a greater influence on the generation of the thermal NOx when compared with that of the inner swirling flow. The maximum average temperature of the central cross section of the combustor does not exceed 1760K. The average mass fraction of the generated thermal NOx at the exit decreases with the increasing outer swirling number. When the outer swirling number is less than 0.8, the generation of the thermal NOx is severe at the side wall of the combustion chamber.

Experimental and Numerical Study on Emission Characteristics of the Double Annular Swirler Under Different Pilot Fuel Ratios

2018 ◽  
Author(s):  
Chao Zong ◽  
Yaya Lyu ◽  
Desan Guo ◽  
Chengqin Li ◽  
Tong Zhu
Keyword(s):  
Nitrogen Oxides ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Numerical Study ◽  
Nox Emission ◽  
Pollutant Emission ◽  
Emission Characteristics ◽  
Micro Gas Turbine ◽  
Pilot Fuel

Micro gas turbine is one of the ideal prime movers for small-distributed energy systems. It can effectively reduce the emission of greenhouse gases and nitrogen oxides. Moreover, the use of micro gas turbines will contribute to burning fossil fuels in a much cleaner way. The staged combustion technology is the favorite way for low pollution combustion chamber such like. Therefore, the influence of the proportion of pilot fuel in the combustion chamber on pollutant emission deserves further study. The object of this research is the Double annular swirler (Das), which was applied to a 100 kW micro gas turbine combustion chamber. The combustion performance and emission characteristics under different Pilot Fuel Ratios (PFR) were obtained in prototype experimental system. Under the experimental conditions, Computational fluid dynamics (CFD) method was applied to research the reacting flow field and the formation of NOx in the combustion chamber and then analyze the influences of PFRs on combustion process. Experimental results show that the NOx emission of Das decreased at first and then increased with the augment of PFR. When PFR was near to 11%, the per unit NOx emission concentration reached its minimum. The numerical simulation agreed well with the experimental data. Further analysis of the simulation results indicate that there is a strong correlation between Φlocal and NOx concentration. When it is lower than a certain value, the number of nitrogen oxides will be significantly reduced. The value has a lot to do with the inlet air temperature and the pressure of the combustion chamber under the design condition, and it needs to be confirmed by calculating the adiabatic temperature. Simultaneously, we also find that although the percentage of total air flowing into the combustor remains unchanged, the increase of PFR would reduce the airflow ratio in inner swirler. This implies that for some particular combustion chambers, special attention should be paid to the changes in air allocation caused by PFR.

Performance and Emission Levels in Gas Turbine Plants

1992 ◽  
Author(s):  
Fabio Bozza ◽  
Raffaele Tuccillo ◽  
Gustavo Fontana
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Carbon Dioxide Emissions ◽  
Coal Gasification ◽  
Pressure Ratio ◽  
Nox Reduction ◽  
Steam Injection ◽  
Pollutant Emission ◽  
Accurate Analysis ◽  
Performance And Emission

The rise in gas turbine combustion chamber temperatures requires optimal choices to be made with regard not only to performance parameters but also with a view to resolving pollutant emission problems. For this reason, the authors have set up a gas turbine cycle model which performs an accurate analysis of several processes, in terms of operating fluid chemical and thermodynamic properties. The model also enables prediction of NOx formation based upon chemical kinetics and is able to relate the amount of pollutants to a number of operating parameters (e.g. cycle pressure ratio, fuel to air equivalence ratio, residence time in combustion chamber, etc.). It can also predict the effect of the most usual NOx reduction systems, such as water or steam injection. A comparison of several possible choices for the gas and combined cycles is then presented, in terms of thermodynamic performance (e.g. first and second law analysis) and nitric and carbon dioxide emissions. In order to find the best compromise between performance improvement and limitation of pollutant emission, enhanced gas cycles are also considered, such as STIG or intecooled-reheat cycles. Examples also refer to medium or low BTU gases, obtained from coal gasification, in order to show not only the possible advantages in terms of thermal NOx reduction, but also the significant amounts of “fuel NOx“ which can arise from ammonia contained in the fuel.

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.

BASIC POSITIONS OF THE ENTHALPY-ENTROPY METHODOLOGY OF THERMODYNAMIC ANALYSIS OF GAS TURBINE POWER PLANTS

2017 ◽  
Author(s):  
Gennadii Liubchik ◽  
◽  
Nataliia Fialko ◽  
Aboubakr Regragui ◽  
Nataliia Meranova ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Thermodynamic Parameters ◽  
Thermodynamic Analysis ◽  
Thermodynamic Modeling ◽  
Power Plants ◽  
Regression Equations ◽  
Thermal Entropy ◽  
Nodal Points ◽  
Computational Diagnostics

The basic positions of the enthalpy-entropy methodology of thermodynamic modeling of processes in gas turbine units (GTUs) and combined power plants on basis GTUs are presented. The main requirements and conditions of this methodology are formulated, they allows the construction of a sequential (without iterations) algorithm for the computational diagnostics of the thermodynamic parameters of the GTU cycle, which includes the calculation blocks for the compressor, combustion chamber, turbine, and exhaust tube of the GTU. The obtained regression equations are presented. The use of these equations simplifies of the procedure for evaluating the thermodynamic parameters of the components at the nodal points of the cycle. The advantages of the proposed methodology in comparison with the traditional thermal-entropy methodology are indicated.

Effect of Divergence Angle on Flow Through Inlet Section of Diffuser of a Gas Turbine Combustion Chamber: The CFD Approach

2006 ◽  
Author(s):  
Digvijay B. Kulshreshtha ◽  
S. A. Channiwala ◽  
Jitendra Chaudhary ◽  
Zoeb Lakdawala ◽  
Hitesh Solanki ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Total Pressure ◽  
Divergence Angle ◽  
Velocity Head ◽  
Turbine Engine ◽  
Inlet Velocity ◽  
Pressure Losses ◽  
Flow Through ◽  
Mach Numbers

In the combustor inlet diffuser section of gas turbine engine, high-velocity air from compressor flows into the diffuser, where a considerable portion of the inlet velocity head PT3 − PS3 is converted to static pressure (PS) before the airflow enters the combustor. Modern high through-flow turbine engine compressors are highly loaded and usually have high inlet Mach numbers. With high compressor exit Mach numbers, the velocity head at the compressor exit station may be as high as 10% of the total pressure. The function of the diffuser is to recover a large proportion of this energy. Otherwise, the resulting higher total pressure loss would result in a significantly higher level of engine specific fuel consumption. The diffuser performance must also be sensitive to inlet velocity profiles and geometrical variations of the combustor relative to the location of the pre-diffuser exit flow path. Low diffuser pressure losses with high Mach numbers are more rapidly achieved with increasing length. However, diffuser length must be short to minimize engine length and weight. A good diffuser design should have a well considered balance between the confliction requirements for low pressure losses and short engine lengths. The present paper describes the effect of divergence angle on diffuser performance for gas turbine combustion chamber using Computational Fluid Dynamic Approach. The flow through the diffuser is numerically solved for divergence angles ranging from 5 to 25°. The flow separation and formation of wake regions are studied.

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