NOx Measurements for Combustor With Acoustically Controlled Primary Zone

1997 ◽  
Vol 119 (3) ◽  
pp. 559-565 ◽  
Author(s):  
P. J. Vermeulen ◽  
V. Ramesh
Keyword(s):  
Operating Conditions ◽  
Gas Temperature ◽  
Mixing Processes ◽  
Jet Mixing ◽  
Air Jets ◽  
Air Jet ◽  
A Value ◽  
Primary Zone ◽  
Turbine Design ◽  
Lean Conditions

Successful NOx measurements at the end of the primary zone of a small tubular combustor of conventional gas turbine design, employing acoustically controlled primary zone air-jet mixing processes, have been made at scaled 1/4 and 1/8 load operating conditions. Testing at 1/8 load significantly increased the effective strength of the acoustic drive, which strongly improved the mixing by the acoustically driven primary zone air-jets. The acoustic drive caused partial blockage of the combustor primary zone airflow. This increased the equivalence ratio and the gas temperature, and made the gas temperature distribution more uniform, except for lean conditions at 1/8 load, in the plane of the NOx measurements. This explained the measured greater NOx “with-drive,” and the distinctly more uniform NOx distribution, which confirmed that mixing was acoustically augmented. The acoustically produced changes were greater at 1/8 load. The acoustic drive significantly changed the combustor operating characteristic so far as mean NOx was concerned, and under lean conditions at 1/8 load mean NOx was reduced, indicating that a value of 10 ppm is possible (a 50 percent reduction).

scholarly journals NO x Measurements for Combustor With Acoustically Controlled Primary Zone

1996 ◽  
Author(s):  
Peter J. Vermeulen ◽  
Venkataramanayya Ramesh
Keyword(s):  
Operating Conditions ◽  
Gas Temperature ◽  
Mixing Processes ◽  
Jet Mixing ◽  
Air Jets ◽  
Air Jet ◽  
A Value ◽  
Primary Zone ◽  
Turbine Design ◽  
Lean Conditions

Successful NOx measurements at the end of the primary zone of s small tubular combustor of conventional gas turbine design, employing acoustically controlled primary zone air-jet mixing processes, have been made at scaled 1/4 and 1/5 load operating conditions. Testing at 1/5 load significantly increased the effective strength of the acoustic drive which strongly improved the mixing by the acoustically driven primary zone air-jets. The acoustic drive caused partial blockage of the combustor primary zone air flow. This increased the equivalence ratio and the gas temperature, and made the gas temperature distribution more uniform, except for lean conditions at 1/5 load, in the plane of the NOx, measurements. This explained the measured greater NOx, “with-drive”, and the distinctly more uniform NOx, distribution which confirmed that mixing was acoustically augmented. The acoustically produced changes were greater at 1/5 load. The acoustic drive significantly changed the combustor operating characteristic so far as mean NOx was concerned, and under lean conditions st 1/5 load mean NOx was reduced indicating that a value of 10 ppm is possible (a 50% reduction).

Acoustically Controlled Combustor NOx

1997 ◽  
Author(s):  
Peter J. Vermeulen ◽  
Venkataramanayya Ramesh
Keyword(s):  
Gas Turbine ◽  
Equivalence Ratio ◽  
Operating Conditions ◽  
Inlet Pipe ◽  
Air Inlet ◽  
A Value ◽  
Design Changes ◽  
Primary Zone ◽  
Turbine Design ◽  
Lean Conditions

Successful NOx measurements in the end plane of the primary zone of a small tubular gaseous fuelled combustor of conventional gas turbine design, employing acoustic driving of the combustor via the air inlet pipe, have been made at scaled 1/8 load operating conditions. The acoustic drive caused partial blockage of the combustor primary zone air flow which increased the equivalence ratio in the plane of the NOx measurements. The mixing was acoustically augmented which together with the blockage richening significantly changed the combustor mean NOx-mean equivalence ratio characteristic in the end plane of the combustor primary zone. Under lean-conditions at 1/8 load and “with-drive” at 246 Hz mean NOx was reduced indicating that a value of 10ppm (50% reduction) is possible, confirming previous results. Under rich-conditions NOx “with-drive” at 246 Hz might be reduced by 23%, relative to previous results, and even might reach the “no-drive” value of about 25ppm, which was possibly due to acoustic augmentation of the primary zone aerodynamics. The NOx at the combustor exhaust “with-drive” should be even lower than that measured “with-drive” because of normal dilution. Therefore, the technique has the potential to create a low NOx conventional combustor without requiring the complicated design-changes of current industry efforts.

Acoustically Controlled Combustor NOx

1998 ◽  
Author(s):  
Peter J. Vermeulen ◽  
Venkataramanayya Ramesh
Keyword(s):  
Gas Turbine ◽  
Equivalence Ratio ◽  
Operating Conditions ◽  
Inlet Pipe ◽  
Air Inlet ◽  
A Value ◽  
Design Changes ◽  
Primary Zone ◽  
Turbine Design ◽  
Lean Conditions

Successful NOx measurements in the end plane of the primary zone of a small tubular gaseous fuelled combustor of conventional gas turbine design, employing acoustic driving of the combustor via the air inlet pipe, have been made at scaled 1/8 load operating conditions. The acoustic drive caused partial blockage of the combustor primary zone air flow which increased the equivalence ratio in the plane of the NOx measurements. The mixing was acoustically augmented which together with the blockage richening significantly changed the combustor mean NOx–mean equivalence ratio characteristic in the end plane of the combustor primary zone. Under lean-conditions at 1/8 load and “with-drive” at 246 Hz mean NOx was reduced indicating that a value of 10ppm (50% reduction) is possible, confirming previous results. Under rich-conditions NOx “with-drive” at 246 Hz might be reduced by 23%, relative to previous results, and even might reach the “no-drive” value of about 25ppm, which was possibly due to acoustic augmentation of the primary zone aerodynamics. The NOx at the combustor exhaust “with-drive” should be even lower than that measured “with-drive” because of normal dilution. Therefore, the technique has the potential to create a low NOx conventional combustor without requiring the complicated design-changes of current industry efforts.

Mixing of an Acoustically Excited Air Jet With a Confined Hot Crossflow

1992 ◽  
Vol 114 (1) ◽  
pp. 46-54 ◽  
Author(s):  
P. J. Vermeulen ◽  
P. Grabinski ◽  
V. Ramesh
Keyword(s):  
Strouhal Number ◽  
Temperature Profiles ◽  
Measured Temperature ◽  
Mixing Zone ◽  
Wake Region ◽  
Mixing Processes ◽  
Jet Mixing ◽  
Air Jet ◽  
Percent Increase ◽  
Jet Structure

The mixing of an acoustically pulsed air jet with a confined hot crossflow has been assessed by temperature profile measurements. These novel experiments were designed to examine the effects of acoustic driver power and Strouhal number on jet structure, penetration, and mixing. The results showed that excitation produced strong changes in the measured temperature profiles. This resulted in significant increases in mixing zone size, penetration (at least 100 percent increase), and mixing, and the length to achieve a given mixed state was shortened by at least 70 percent. There was strong modification to the jet-wake region. The increase in jet penetration and mixing was saturating near 90 W, the largest driving power tested. The jet response as determined by penetration and mixing was optimum at a Strouhal number of 0.27. Overall, pulsating the jet flow significantly improved the jet mixing processes in a controllable manner.

Acoustic control of combustor primary zone air-jet mixing

1992 ◽  
Author(s):  
P. VERMEULEN ◽  
V. RAMESH ◽  
B. SANDERS ◽  
J. ODGERS
Keyword(s):  
Jet Mixing ◽  
Air Jet ◽  
Acoustic Control ◽  
Primary Zone

scholarly journals A Variable-Geometry Combustor Used to Study Primary and Secondary Zone Stoichiometry

1983 ◽  
Author(s):  
Daniel Briehl ◽  
Donald F. Schultz ◽  
Robert C. Ehlers
Keyword(s):  
Operating Conditions ◽  
Fuel Quality ◽  
Variable Geometry ◽  
Gas Temperature ◽  
Reference Velocity ◽  
Primary Zone ◽  
Wide Range ◽  
Secondary Zone ◽  
And Performance ◽  
Exhaust Gas Temperature

A combustion program is underway to evaluate fuel quality effects on gas turbine combustors. A rich-lean variable geometry combustor design was chosen to evaluate fuel quality effects over a wide range of primary and secondary zone equivalence ratios at simulated engine operating conditions. The first task of this effort, was to evaluate the performance of the variable geometry combustor. The combustor incorporates three stations of variable geometry to control primary and secondary zone equivalence ratio and overall pressure loss. Geometry changes could be made while a test was in progress through the use of remote control actuators. The primary zone liner was water cooled to eliminate the concern of liner durability. Emissions and performance data were obtained at simulated engine conditions of 80 percent and full power. Inlet air temperature varied from 611 to 665 K, inlet total pressure varied from 1.02 to 1.24 MPa, reference velocity was 18.0 m/sec and exhaust gas temperature was a constant 1400 K.

The Mechanics of Flame and Air Jets

1937 ◽  
Vol 137 (1) ◽  
pp. 11-72 ◽  
Author(s):  
R. F. Davis
Keyword(s):  
Axial Direction ◽  
Flame Length ◽  
Similar Process ◽  
Mean Velocity ◽  
Ignition Point ◽  
Jet Mixing ◽  
Air Jets ◽  
Air Jet ◽  
The Mean ◽  
Secondary Air

Consideration of the conditions existing within the turbulent zone formed by a free disperse jet mixing with fluid at rest surrounding it, leads to the conception of an equation for the mean velocity of the jet in an axial direction. Combining the latter equation with that for the upward drift velocity of the gases in a furnace, an expression is obtained for the trajectory of an overfire, or secondary air jet, projected into the furnace. By a similar process the method is extended to the case of a flame jet, taking into account its acceleration due to buoyancy. The mechanism of combustion is next considered, commencing with an examination of the factors controlling the position of the ignition point in a flame jet, and the derivation of an expression for its location in a powdered-fuel flame. This is followed by the development of a formula for the burning rate of powdered fuel suspended in air, which when combined with that for the mean velocity in a flame jet, enables a relationship to be established between the flame length and the particle size, for the ideal case of a uniform powder. Subsequently, the grading or non-uniform nature of actual powders is taken into account. A method is also described for plotting a flame characteristic, showing the effect of fineness of grinding, turbulence, and burner design on the losses due to unburnt combustible.

Low NOx Primary Zones Using Jet Mixing Shear Layer Combustion

1988 ◽  
Author(s):  
U. S. Abdul Hussain ◽  
G. E. Andrews ◽  
W. G. Cheung ◽  
A. R. Shahabadi
Keyword(s):  
Natural Gas ◽  
Shear Layer ◽  
Gas Turbines ◽  
Scale Up ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Jet Mixing ◽  
Primary Zone

An interacting radial and axial multi jet shear layer combustion system is described that has the rapid fuel and air mixing characteristics necessary for low NOx emissions. The radial jet has the fuel mixed with a proportion of the total primary zone flow and a 30% proportion was investigated. This radial jet was fuel rich at most primary zone operating conditions and ensured a flame stability far superior to the premixed situation. The scale up of the design from a 76mm to a 140mm diameter combustor was investigated. It was demonstrated that the distance the radial jet travelled before encountering the rapid mixing with the axial jets, had a strong influence on the combustion efficiency and NOx emissions. For both the 76 and 140mm combustors it was shown that the NOx emissions with propane were 50% greater than those for natural gas. It was also demonstrated that the low NOx emissions of the 76mm system were retained in the larger combustor with the same single central fuel injector design. There was a significant increase in NOx for some 140mm combustor configurations, but the emissions corrected to 15% oxygen below 10ppm were demonstratred, with a high combustion efficiency. The design thus demonstrated, in a practical combustor size, the potential for a dry solution to the NOx emissions problem of natural gas fired industrial gas turbines.

Mixing of an Acoustically Excited Air Jet With a Confined Hot Crossflow

1990 ◽  
Author(s):  
P. J. Vermeulen ◽  
P. Grabinski ◽  
V. Ramesh
Keyword(s):  
Strouhal Number ◽  
Temperature Profiles ◽  
Measured Temperature ◽  
Mixing Zone ◽  
Wake Region ◽  
Zone Size ◽  
Mixing Processes ◽  
Jet Mixing ◽  
Air Jet ◽  
Jet Structure

The mixing of an acoustically pulsed air jet with a confined hot crossflow has been assessed by temperature profile measurements. These novel experiments were designed to examine the affects of acoustic driver power and Strouhal number on jet structure, penetration and mixing. The results showed that excitation produced strong changes in the measured temperature profiles. This resulted in significant increases in mixing zone size, penetration (at least 100% increase), mixing, and the length to achieve a given mixed state was shortened by at least 70%. There was strong modification to the jet-wake region. The increase in jet penetration and mixing was saturating near 90 W the largest driving power tested. The jet response as determined by penetration and mixing was optimum at a Strouhal number of 0.27. Overall, pulsating the jet flow significantly improved the jet mixing processes in a controllable manner.

scholarly journals Reduction of soot carbon in the exhaust gases of a tractor gas-diesel engine

2021 ◽  
Vol 2094 (5) ◽  
pp. 052068
Author(s):  
A P Akimov ◽  
P L Lekomtsev ◽  
V A Likhanov ◽  
O P Lopatin ◽  
A O Vasiliev
Keyword(s):  
Natural Gas ◽  
Gas Phase ◽  
Turbulent Jets ◽  
Mixing Process ◽  
Mixing Processes ◽  
Carbon Particles ◽  
Air Jets ◽  
A Value ◽  
Soot Carbon ◽  
Gas Flame

Abstract The rate of oxidation of carbon (including its dispersed forms) has a value much higher than the rate of gasification. Therefore, in the initial part of the flame, when oxygen is still contained in the gas phase, the oxidation of soot will be the process on which the change in the size and concentration of dispersed carbon particles mainly depends. The intensity of oxidation and gasification of dispersed carbon in the flame largely depends on the development of the mixing process, determined by the aerodynamics of the fuel and air jets. The paper presents an analysis of the influence of mixing processes on the oxidation and gasification of dispersed carbon in a natural gas flame in the study of homogeneous flames and mixing of turbulent jets. The results of industrial studies of the mixing of fuel and air in a diffusion torch are taken into account. The results allow us to evaluate the influence of various aerodynamic factors on the processes occurring in the glowing flame of natural gas in the combustion chamber of gas diesel.

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