Variable Geometry, Lean, Premixed, Prevaporized Fuel Combustor Conceptual Design Study

1980 ◽  
Vol 102 (4) ◽  
pp. 896-902 ◽  
Author(s):  
A. J. Fiorentino ◽  
W. Greene ◽  
J. C. Kim ◽  
E. J. Mularz
Keyword(s):  
Conceptual Design ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Variable Geometry ◽  
Design Study ◽  
Flow Modulation ◽  
Lean Premixed ◽  
Unburned Hydrocarbons ◽  
And Performance

Four lean premixed prevaporized (LPP) combustor concepts have been identified which utilize variable geometry and/or other flow modulation techniques to control the equivalence ratio of the initial burning zone. Lean equivalence ratios are maintained at high power engine operating conditions for low NOx emissions, while near stoichiometric conditions are maintained at low power for good combustion efficiency and low emissions of carbon monoxide and unburned hydrocarbons. The primary goal of this program was to obtain a low level of NOx emissions (≤3 g/kg fuel) at stratospheric cruise conditions; additional goals are to achieve the currently proposed 1984 EPA emission standards over the landing/take off cycle and performance and operational requirements typical of advanced aircraft engines. Based on analytical projections made during this conceptual design study, two of the concepts offer the potential of achieving the emission goals. However, the projected operational characteristics and reliability of these concepts to perform satisfactorily over an entire flight envelope would require extensive experimental substantiation before an engine application can be considered.

Effects of Cycle Operating Conditions on Combustor Performance

1997 ◽  
Vol 119 (1) ◽  
pp. 45-49 ◽  
Author(s):  
N. T. Davis ◽  
V. G. McDonell ◽  
G. S. Samuelsen
Keyword(s):  
Cost Function ◽  
Duty Cycle ◽  
Load Condition ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Variable Geometry ◽  
Oxides Of Nitrogen ◽  
Mixing Processes ◽  
The Cost

To mitigate the environmental impact of next-generation gas turbine combustors, the emission performance at each condition throughout the load duty cycle must be optimized. Achieving this with a single combustor geometry may not be possible. Rather, the mixing processes and airflow splits must likely be modified as a function of load in order to (1) abate the emission of oxides of nitrogen, (2) maintain combustion efficiency, and (3) preclude lean blow-out over the entire duty cycle. The present study employs a model combustor to evaluate combustor performance as a function of load and explore the application of variable geometry to optimize performance at each condition. A parametric variation of flow splits is conducted at each load condition by independently adjusting the primary jet area and swirler choke area. The resultant impact on combustor performance is measured and quantified in terms of a cost function. The cost function is defined to increase with improving combustor performance (e.g., improving combustion efficiency and/or declining NOx emissions). Cycle operating conditions are found to alter the response mappings of efficiency and NOx. As a result, the optimal configuration of the combustor changes as the load is varied over the duty cycle. The results provide guidance on the application of active control.

Effects of Cycle Operating Conditions on Combustor Performance

1995 ◽  
Author(s):  
N. T. Davis ◽  
V. G. McDonell ◽  
G. S. Samuelsen
Keyword(s):  
Cost Function ◽  
Duty Cycle ◽  
Load Condition ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Variable Geometry ◽  
Oxides Of Nitrogen ◽  
Mixing Processes ◽  
The Cost

To mitigate the environmental impact of next generation gas turbine combustors, the emission performance at each condition throughout the load duty cycle must be optimized. Achieving this with a single combustor geometry may not be possible. Rather, the mixing processes and air flow splits must likely be modified as a function of load in order to (1) abate the emission of oxides of nitrogen, (2) maintain combustion efficiency, and (3) preclude lean blow out over the entire duty cycle. The present study employs a model combustor to evaluate combustor performance as a function of load and explore the application of variable geometry to optimize performance at each condition. A parametric variation of flow splits is conducted at each load condition by independently adjusting the primary jet area and swirler choke area. The resultant impact on combustor performance is measured and quantified in terms of a cost function. The cost function is defined to increase with improving combustor performance (e.g., improving combustion efficiency and/or declining NOx emissions). Cycle operating conditions are found to alter the response mappings of efficiency and NOx. As a result, the optimal configuration of the combustor changes as the load is varied over the duty cycle. The results provide guidance on the application of active control.

Engine Testing of a Natural Gas-Fired, Low-NOx, Variable Geometry Gas Turbine Combustor for a Small Gas Turbine

1996 ◽  
Author(s):  
Shigeru Hayashi ◽  
Hideshi Yamada ◽  
Kazuo Shimodaira
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Variable Geometry ◽  
Wide Range ◽  
Lean Premixed ◽  
Full Power ◽  
Engine Testing

The development of a variable geometry lean-premixed combustor is in progress at NAL. Engine testing has been cooducted by using a natural gas-fueled 210-kW gas turbine to demonstrate the capability of ultra-low NOx emissions over a wide range of eogine operation. This paper describes the effort of engine testing of the combustor to achieve NOx emissions of the 10-ppm level. Fuel was staged to the non-premixed pilot and premixed main burners. A butterfly valve air splitting system was employed to maintain both low NOx emissions and high efficieocy over a wide operating range of the engine. The engioe was operated in the lean-premixed, low NOx emissions mode from idle to full power. Over the whole operating conditions from idle to full power, NOx emissions were reduced to levels less than 25 ppm (15% O2 dry). The NOx emissions level for a nearly constant combustion efficiency decreased with increasing power or turbine inlet temperature. At operating conditions of 90% to full power, NOx emissions levels of 12 to 8 ppm (15% O2 dry) were measured with combustion efficiencies of 99.7 to 99.1%.

Combustion Characteristics of Small Size Gas Turbine Combustor Fueled by Biomass Gas Employing Flameless Combustion

2007 ◽  
Author(s):  
Masato Hiramatsu ◽  
Yoshifumi Nakashima ◽  
Sadamasa Adachi ◽  
Yudai Yamasaki ◽  
Shigehiko Kaneko
Keyword(s):  
Gas Turbine ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Flameless Combustion ◽  
Engine Exhaust ◽  
Micro Gas Turbine

One approach to achieving 99% combustion efficiency (C.E.) and 10 ppmV or lower NOx (at 15%O2) in a micro gas turbine (MGT) combustor fueled by biomass gas at a variety of operating conditions is with the use of flameless combustion (FLC). This paper compares experimentally obtained results and CHEMKIN analysis conducted for the developed combustor. As a result, increase the number of stage of FLC combustion enlarges the MGT operation range with low-NOx emissions and high-C.E. The composition of fuel has a small effect on the characteristics of ignition in FLC. In addition, NOx in the engine exhaust is reduced by higher levels of CO2 in the fuel.

scholarly journals Swirl-Can Combustor Performance to Near-Stoichiometric Fuel-Air Ratio

1976 ◽  
Author(s):  
L. A. Diehl ◽  
J. A. Biaglow
Keyword(s):  
Air Temperature ◽  
Combustion Efficiency ◽  
Oxides Of Nitrogen ◽  
Module Design ◽  
Air Temperatures ◽  
Nitrogen Emission ◽  
Unburned Hydrocarbons ◽  
Exit Temperature ◽  
And Performance ◽  
Emissions And Performance

Emissions and performance characteristics were determined for two full-annulus swirl-can modular combustors operated to near-stoichiometric fuel air ratios. The purposes of the tests were to obtain stoichiometric data at inlet-air temperatures up to 894 K and to determine the effect of module number by investigating 120 and 72 module swirl-can combustors. The maximum average exit temperature obtained with the 120-module swirl-can combustor was 2465 K with a combustion efficiency of 95 percent at an inlet-air temperature of 894 K. The 72-module swirl-can combustor reached a maximum average exit temperature of 2306 K with a combustion efficiency of 92 percent at an inlet-air temperature of 894 K. At a constant inlet air temperature, maximum oxides of nitrogen emission index values occurred at a fuel-air ratio of 0.037 for the 72-module design and 0.044 for the 120-module design. The combustor average exit temperature and combustion efficiency were calculated from emissions measurements. The measured emissions included carbon monoxide, unburned hydrocarbons, oxides of nitrogen, and smoke.

Investigation on Flowfield and Fuel/Air Premixing Uniformities of Low Swirl Injector for Lean Premixed Gas Turbines

2021 ◽  
Author(s):  
Fujun Sun ◽  
Jianqin Suo ◽  
Zhenxia Liu
Keyword(s):  
Penetration Depth ◽  
Residence Time ◽  
Gas Turbines ◽  
Structural Parameters ◽  
Combustible Mixture ◽  
Operating Conditions ◽  
Flame Stability ◽  
Nox Emissions ◽  
Auto Ignition ◽  
Lean Premixed

Abstract Based on the development trend of incorporating fuel holes into swirler-vanes and the advantages of wide operating conditions as well as low NOx emissions of LSI, this paper proposes an original lean premixed LSI with a convergent outlet. The influence of key structures on flowfields and fuel/air premixing uniformities of LSI is investigated by the combination of laser diagnostic experiments and numerical simulations. The flowfields of LSI shows that the main recirculation zone is detached from the convergent outlet and its axial dimensions are smaller than that of HSI, which can decrease the residence time of high-temperature gas to reduce NOx emissions. The fuel/air premixing characteristics show that the positions and diameters of fuel holes affect fuel/air premixing by changing the penetration depth of fuel. And when the penetration depth is moderate, it can give full play to the role of swirling air in enhancing premixing of fuel and air. In addition, the increase of the length of the premixing section can improve the uniformity of fuel/ar premixing, but it can also weaken the swirl intensity and increase the residence time of the combustible mixture within the LSI, which can affect flame stability and increase the risk of auto-ignition. Therefore, the design and selection of LSI structural parameters should comprehensively consider the requirements of fuel/air mixing uniformity, flame stability and avoiding the risk of auto-ignition. The results can provide the technical basis for LSI design and application in aero-derivative and land-based gas turbine combustors.

Development of a Natural Gas-Fired, Ultra-Low NOx Can Combustor for an 800 KW Gas Turbine

1991 ◽  
Author(s):  
K. O. Smith ◽  
A. C. Holsapple ◽  
H. K. Mak ◽  
L. Watkins
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Premixed Combustion ◽  
Experimental Results ◽  
Nox Emissions ◽  
Variable Geometry ◽  
Lean Premixed Combustion ◽  
Full Load ◽  
Primary Zone ◽  
Lean Premixed

The experimental results from the rig testing of an ultra-low NOx, natural gas-fired combustor for an 800 to 1000 kw gas turbine are presented. The combustor employed lean-premixed combustion to reduce NOx emissions and variable geometry to extend the range over which low emissions were obtained. Testing was conducted using natural gas and methanol. Testing at combustor pressures up to 6 atmospheres showed that ultra-low NOx emissions could be achieved from full load down to approximately 70% load through the combination of lean-premixed combustion and variable primary zone airflow.

scholarly journals Variable Geometry Fuel Injector for Low Emissions Gas Turbines

1999 ◽  
Author(s):  
K. Smith ◽  
R. Steele ◽  
J. Rogers
Keyword(s):  
Gas Turbines ◽  
Field Tests ◽  
Flow Distribution ◽  
Operating Conditions ◽  
Variable Geometry ◽  
Fuel Injector ◽  
System Variable ◽  
Lean Premixed Combustion ◽  
Stable Operating ◽  
Lean Premixed

To extend the stable operating range of a lean premixed combustion system, variable geometry can be used to adjust the combustor air flow distribution as gas turbine operating conditions vary. This paper describes the design and preliminary testing of a lean premixed fuel injector that provides the variable geometry function. Test results from both rig and engine evaluations using natural gas are presented. The variable geometry injector has proven successful in the short-term testing conducted to date. Longer term field tests are planned to demonstrate durability.

Quantifying Unmixedness in Lean Premixed Combustors Operating at High Pressure, Fired Conditions

1997 ◽  
Author(s):  
J. C. Barnes ◽  
A. M. Mellor
Keyword(s):  
High Pressure ◽  
Characteristic Time ◽  
Low Pressure ◽  
Companion Paper ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Time Model ◽  
Cold Flow ◽  
Lean Premixed ◽  
Consistent Method

Lean premixed combustor manufacturers require premixer concepts that provide homogeneity (mixedness) of the fuel which burns in the main flame. Ideally premixer evaluation would be conducted under realistic combustor operating conditions. However, current techniques typically are limited to cold—flow, low pressure (<14 atm) conditions or comparison of measured NOx emissions with others obtained in premixed systems. Thus, a simple, consistent method for quantifying unmixedness in lean premixed combustors operating at high pressure, fired operating conditions is proposed here, using the characteristic time model developed in the companion paper.

Preliminary design and performance analysis of a low emission aero-derived gas turbine combustor

2013 ◽  
Vol 117 (1198) ◽  
pp. 1249-1271 ◽  
Author(s):  
B. Khandelwal ◽  
A. Karakurt ◽  
V. Sethi ◽  
R. Singh ◽  
Z. Quan
Keyword(s):  
Gas Turbine ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Gas Turbine Combustor ◽  
Detailed Method ◽  
Low Emission ◽  
Heat Shields ◽  
Lean Fuel ◽  
Reduce Emissions ◽  
And Performance

Abstract Modern gas turbine combustor design is a complex task which includes both experimental and empirical knowledge. Numerous parameters have to be considered for combustor designs which include combustor size, combustion efficiency, emissions and so on. Several empirical correlations and experienced approaches have been developed and summarised in literature for designing conventional combustors. A large number of advanced technologies have been successfully employed to reduce emissions significantly in the last few decades. There is no literature in the public domain for providing detailed design methodologies of triple annular combustors. The objective of this study is to provide a detailed method designing a triple annular dry low emission industrial combustor and evaluate its performance, based on the operating conditions of an industrial engine. The design methodology employs semi-empirical and empirical models for designing different components of gas turbine combustors. Meanwhile, advanced DLE methods such as lean fuel combustion, premixed methods, staged combustion, triple annular, multi-passage diffusers, machined cooling rings, DACRS and heat shields are employed to cut down emissions. The design process is shown step by step for design and performance evaluation of the combustor. The performance of this combustor is predicted, it shows that NO x emissions could be reduced by 60%-90% as compared with conventional single annular combustors.

Sign in / Sign up

Export Citation Format

Share Document