scholarly journals Experimental Investigation of an Atmospheric Rectangular Rich Quench Lean Combustor Sector for Aeroengines

1997 ◽  
Author(s):  
Peter Griebel ◽  
Michael Fischer ◽  
Christoph Hassa ◽  
Eggert Magens ◽  
Henning Nannen ◽  
...  
Keyword(s):  
Research Work ◽  
Nox Formation ◽  
Lean Combustion ◽  
Air Jets ◽  
Primary Zone ◽  
Low Emission ◽  
Measuring Techniques ◽  
Annular Combustor ◽  
High Turbulence ◽  
Secondary Air

In this research work the potential of rich quench lean combustion for low emission aeroengines is investigated in a rectangular atmospheric sector, representing a segment of an annular combustor. For a constant design point (cruise) the mixing process and the NOx formation are studied in detail by concentration, temperature and velocity measurements using intrusive and non-intrusive measuring techniques. Measurements at the exit of the homogeneous primary zone show relatively high levels of non-thermal NO. The NOx formation in the quench zone is very low due to the quick mixing of the secondary air achieved by an adequate penetration of the secondary air jets and a high turbulence level. The NOx and CO emissions at the combustor exit are low and the pattern factor of the temperature distribution is sufficient.

scholarly journals Mathematical Modelling of an Annular Gas Turbine Combustor

1993 ◽  
Author(s):  
K. Y. Sokolov ◽  
A. G. Tumanovskiy ◽  
M. N. Gutnik ◽  
A. V. Sudarev ◽  
Y. I. Zakharov ◽  
...  
Keyword(s):  
Reynolds Equation ◽  
Experimental Investigations ◽  
Diffusion Combustion ◽  
Operational Parameters ◽  
Gas Turbine Combustor ◽  
Nox Formation ◽  
Air Jets ◽  
Annular Combustor ◽  
Flow Heat ◽  
Swirled Flow

Mathematical model for description of axisymmetric swirled flow with diffusion combustion is based on numerical solution of Reynolds equation with k-W modell of turbulence. The results of numerical and experimental investigations of local and general characteristicse of flow, heat and mass transfer, combustion and NOx formation in annular combustor with opposite swirled air jets are presented. Satisfactory agreement between calculations and experiments is obtained. The dependences of combustor characteristics vs geometric and operational parameters are generalized.

scholarly journals Fundamental Study on Ammonia Low-NOx Combustion Using Two-Stage Combustion by Parallel Air Jets

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 23
Author(s):  
Kenta Kikuchi ◽  
Ryuichi Murai ◽  
Tsukasa Hori ◽  
Fumiteru Akamatsu
Keyword(s):  
Nox Reduction ◽  
Axial Direction ◽  
Two Stage ◽  
Fundamental Study ◽  
Lean Combustion ◽  
Air Jets ◽  
Stage Combustion ◽  
Low Nox Combustion ◽  
Secondary Air ◽  
Air Nozzle

Ammonia, which has advantages over hydrogen in terms of storage and transportation, is increasingly expected to become a carbon-free fuel. However, the reduction of fuel NOx emitted from ammonia combustion is an unavoidable challenge. There is the report that two-stage combustion with parallel independent jets could achieve Low-NOx combustion under ammonia/methane co-firing conditions. In order to further improve NOx reduction, we experimentally evaluated the effects of secondary air nozzle parameters, such as nozzle diameter and nozzle locations, on combustion characteristics in two-stage combustion of ammonia/natural gas co-firing using parallel independent jets. As a result of the experiments under various secondary air nozzle conditions, it was found that under the conditions where NOx was significantly reduced, the peak temperature in the furnace was observed at 300–500 mm in the axial direction from the burner, and then the temperature decreased toward the downstream of the furnace. We assumed that this temperature distribution reflected the mixing conditions of the fuel and secondary air and estimated the combustion conditions in the furnace. It was confirmed that the two-stage combustion was effective in reducing NOx by forming a fuel rich region near the downstream of the burner, and the lean combustion of the unburned portion of the first stage combustion with secondary air. We confirmed that the low NOx effects could be achieved by two-stage combustion using independent jets from the same wall under appropriate combustion and air nozzle conditions.

Mathematical Modeling of an Annular Gas Turbine Combustor

1995 ◽  
Vol 117 (1) ◽  
pp. 94-99 ◽  
Author(s):  
K. Y. Sokolov ◽  
A. G. Tumanovskiy ◽  
M. N. Gutnik ◽  
A. V. Sudarev ◽  
Y. I. Zakharov ◽  
...  
Keyword(s):  
Reynolds Equation ◽  
Experimental Investigations ◽  
Diffusion Combustion ◽  
Operational Parameters ◽  
Gas Turbine Combustor ◽  
Nox Formation ◽  
Air Jets ◽  
Annular Combustor ◽  
Flow Heat ◽  
Swirled Flow

A mathematical model for the description of axisymmetric swirled flow with diffusion combustion is based on numerical solution of the Reynolds equation with a k–W model of turbulence. The results of numerical and experimental investigations of local and general characteristics of flow, heat and mass transfer, combustion, and NOx formation in an annular combustor with opposite swirled air jets are presented. Satisfactory agreement between calculations and experiments is obtained. The dependences of combustor characteristics versus geometric and operational parameters are generalized.

NOx Reduction in Gas Turbine Combustors With Compact Non-Premixed Flame Front

2014 ◽  
Author(s):  
V. V. Tsatiashvili ◽  
V. G. Avgustinovich
Keyword(s):  
Flame Front ◽  
Gas Turbine ◽  
Nox Reduction ◽  
Premixed Flame ◽  
Nox Emission ◽  
Nox Formation ◽  
New Approach ◽  
Index Reduction ◽  
Primary Zone ◽  
Low Emission

This paper represents results of R&D efforts towards reducing a bypass turbofan engine NOx emission by 45 % compared with CAEP/6 to meet the ICAO NOx emission goal of 2020. To achieve ICAO NOx technology goal, a new approach is used based on the NOx emission reduction in combustors with non-premixed combustion well proved in operation. The new approach is represented by structured system of low emission combustion principles — a concept of combustor featuring compact non-premixed flame (CNPF). The essence of CNPF concept is in suppression of volume and surface NOx formation sources by flame front blocking in liner primary zone and by increasing of fuel effective burning rate. The paper represents the development of concept up to and including the 4th technology maturity level. It demonstrates CNPF concept independence and interaction with other up-to-date gas turbine low emission concepts. The paper indicates comparison of rig test results between in-service combustor and CNPF adopted combustors carried out on a single liner. A CNPF adopted combustor shows NOx emission index reduction by 35 …47 % at take-off engine conditions. Preliminary estimation shows that it is possible to reach the ICAO goal for NOx emission level of 2020.

Calculation of the Flow in a Sector of an Annular Combustor

1989 ◽  
Vol 203 (3) ◽  
pp. 187-193 ◽  
Author(s):  
W P Jones ◽  
M N Sodha ◽  
J J McGuirk
Keyword(s):  
Gas Turbines ◽  
Piecewise Linear ◽  
Turbulent Transport ◽  
Physical Domain ◽  
Measured Velocity ◽  
Acceptable Accuracy ◽  
Primary Zone ◽  
Domain Boundaries ◽  
Annular Combustor ◽  
Measured Flow

Calculations have been made of the isothermal flow field within a sector of an annular combustion chamber representative of the type to be found in small gas turbines. The complex combustor geometry is described using a Cartesian finite difference mesh within which the physical domain boundaries are represented in a piecewise linear fashion. The k-s turbulence model is used to describe turbulent transport. Overall the calculated and measured flow fields are found to be in reasonable agreement and in the primary zone measured velocity profiles are reproduced to within an acceptable accuracy.

Development of a Lean-Premixed Two-Stage Annular Combustor for Gas Turbine Engines

1994 ◽  
Author(s):  
Fred C. Bahlmann ◽  
B. Martien Visser
Keyword(s):  
Gas Turbine ◽  
Turbine Engines ◽  
Emission Characteristics ◽  
Gas Turbine Engines ◽  
Two Stage ◽  
Low Emission ◽  
Lean Premixed ◽  
Annular Combustor

The development, from concept to hardware of a lean-premixed two-stage combustor for small gas turbine engines is presented. This Annular Low Emission Combustor (ALEC) is based on a patent of R.J. Mowill. Emission characteristics of several prototypes of this combustor under a variety of conditions are presented. It is shown that ultra-low NOx levels (< 10 ppm) can be reached with satisfactory CO levels (< 50 ppm).

Experimental and computational investigations of flow dynamics in LPP combustor

2017 ◽  
Vol 121 (1240) ◽  
pp. 790-802 ◽  
Author(s):  
Y. W. YAN ◽  
Y. P. Liu ◽  
Y. C. Liu ◽  
J. H. Li
Keyword(s):  
Recirculation Zone ◽  
Swirling Flow ◽  
Mixing Layer ◽  
Experimental Tests ◽  
Flow Dynamics ◽  
Reynolds Stresses ◽  
Lean Combustion ◽  
Low Emission ◽  
Image Velocimetry ◽  
Combustion Technology

ABSTRACTA Lean Premixed Prevaporised (LPP) low-emission combustor with a staged lean combustion technology was developed. In order to study cold-flow dynamics in the LPP combustor, both experimental tests using the particle image velocimetry (PIV) to quantify the flow dynamics and numerical simulation using the commercial software (FLUENT) were conducted, respectively. Numerical results were in good agreement with the experimental data. It is shown from the observation of the results that: there is a Primary Recirculation Zone (PRZ), a Corner Recirculation Zone (CRZ) and a Lip Recirculation Zone (LRZ) in the LPP combustor, and the exchanges of mass, momentum and energy between pilot swirling flow and primary swirling flow are contributed by the velocity gradients, and the shear flow is transformed into a mixing layer exhibiting the higher Reynolds stresses, which suggests the mixing process is strictly affected by the Reynolds stresses.

Development of a Low-Emission Combustor for a 100-kW Automotive Ceramic Gas Turbine (II)

1996 ◽  
Vol 118 (1) ◽  
pp. 167-172 ◽  
Author(s):  
H. Kumakura ◽  
M. Sasaki ◽  
D. Suzuki ◽  
H. Ichikawa
Keyword(s):  
Gas Turbine ◽  
Gasoline Engine ◽  
Standard Test ◽  
Inlet Temperature ◽  
Performance Tests ◽  
Passenger Cars ◽  
Lean Combustion ◽  
Low Emission ◽  
Strength Tests ◽  
Combustion Tests

Performance tests were conducted on a low-emission combustor, which has a pre-vaporization–premixing lean combustion system and is designed for a 100 kW automotive ceramic gas turbine. The results of steady-state combustion tests performed at an inlet temperature of 1000–1200 K and pressure of 0.1–0.34 MPa indicate that the combustor would meet Japan’s emission standards for gasoline engine passenger cars without using an aftertreatment system. Flashback was suppressed by controlling the mixture velocity and air ratios. Strength tests conducted on rings and bars cut from the actual ceramic parts indicate that the combustor has nearly the same level of strength as standard test specimens.

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).

Coupled and Uncoupled CFD Prediction of the Characteristics of Jets From Combustor Air Admission Ports

2000 ◽  
Author(s):  
J. J. McGuirk ◽  
A. Spencer
Keyword(s):  
Internal Flow ◽  
Flow Conditions ◽  
Empirical Correlations ◽  
Weakly Coupled ◽  
Primary Zone ◽  
Annular Combustor ◽  
Alternative Approaches ◽  
Jet Characteristics ◽  
Fully Coupled ◽  
Core Flows

The paper focusses attention on alternative approaches for treating the coupling between the flow in the annulus supply ducts and the jets which enter combustor primary and dilution zones through air admission ports. Traditionally CFD predictions of combustor flows have modeled this in a very weakly-coupled manner, with the port flow conditions being derived from 1D empirical correlations and used as boundary conditions for an internal-flow-only combustor CFD prediction. Recent work by the authors and others has introduced the viewpoint that fully-coupled external-annulus/internal-combustor predictions is the way forward. Experimental data is gathered in the present work to quantify the strength of the interaction between annulus and core flows, which ultimately determines the jet characteristics at port exit. These data are then used to illustrate the improvement in the prediction of port exit jet characteristics which is obtained by adopting fully-coupled calculations compared to the internal-flow-only approach. As a final demonstration of the importance of a fully coupled approach, isothermal calculations are presented for a single sector generic annular combustor. These show that quite different primary zone flow patterns are obtained from the two approaches, leading to considerable differences in the overall mixing pattern at combustor exit.

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