Optimization of a Small Aircraft Combustor to Reduce NOx Emissions Under Practical Conditions

2007 ◽  
Author(s):  
Mitsumasa Makida ◽  
Hideshi Yamada ◽  
Kazuo Shimodaira ◽  
Takeshi Yamamoto ◽  
Shigeru Hayashi
Keyword(s):  
Pressure Ratio ◽  
Load Condition ◽  
Atmospheric Condition ◽  
Aircraft Engine ◽  
Civil Aviation ◽  
Nox Emissions ◽  
Lean Burn ◽  
Lean Blowout ◽  
Fuel Nozzle ◽  
The Rich

A series of research experiments under practical conditions has been conducted to develop a combustor for a small-class aircraft engine (with the pressure ratio of about 20). In the previous research experiments, including ignition and emission tests under atmospheric pressure, we applied a single airblast fuel nozzle and utilized the rich-burn quick-quench lean-burn (RQL) combustion approach. The combustor was tuned to show the behavior of the RQL under the atmospheric condition. In this paper, the results of single-sector combustor experiments under the practical temperature and pressure conditions are presented, in which RQL behavior is observed and NOx emissions in the ICAO (International Civil Aviation Organization) LTO (Landing and Take-Off) cycle are reduced to 45% of the ICAO CAEP4 (Committee on Aviation Environmental Protection 4) standard. Also the results of successive multi-sector combustor tests to optimize combustion performances with a more practical combustor configuration under the practical conditions are presented. The emission characteristics which are obtained are compared with those of the single-sector tests, and combustor size and configuration, air mass flow ratio and air hole positions are tuned through a series of multi-sector experiments. After the optimization, the combustor achieved the following performances; NOx emissions are reduced to less than 42% of the ICAO CAEP4 standard, CO and THC (Total Hydrocarbon) are reduced to those of 2% and 50% respectively, the lean blowout limit is kept over 220 AFR (Air to Fuel Ratio) at the idle condition and the exit temperature profile at the full load condition is sufficiently uniform (P.T.F.<0.15). The process of optimization will be discussed in this report.

Evaluation of Lean Axially Staged Combustion by Multi-Sector Combustor Tests Under LTO Cycle Conditions of a Small Aircraft Engine

2013 ◽  
Author(s):  
Takeshi Yamamoto ◽  
Kazuo Shimodaira ◽  
Yoji Kurosawa ◽  
Seiji Yoshida
Keyword(s):  
Technology Development ◽  
Pressure Ratio ◽  
Nox Reduction ◽  
Aircraft Engine ◽  
Development Project ◽  
Civil Aviation ◽  
Nox Emissions ◽  
Fuel Nozzle ◽  
Conducting Research ◽  
Combustion Tests

JAXA is conducting research and development on aircraft engine technologies to reduce environmental impact in the Technology Development Project for Clean Engines (TechCLEAN). As a part of the project, combustion technologies have been developed with an aggressive target that is an 80% reduction over the NOx threshold of the fourth Committee on Aviation Environmental Protection (CAEP/4) of the International Civil Aviation Organization (ICAO). Lean staged fuel nozzles have been developed and tested using a single-sector combustor under Landing and Take-off (LTO) cycle conditions of the target engine with a rated output of 40 kN and an overall pressure ratio of 25.8. A reduction of 82.2% in LTO NOx emissions relative to the ICAO CAEP/4 standard and drastic reductions in smoke and carbon monoxide (CO) emissions were resulted by single-sector combustor tests of a lean staged combustor with an additional premixed fuel nozzle (ECF: Emission Control Fuel nozzle). After the test, the pilot mixer of the single-sector combustor was improved and an additional 2.5% NOx reduction was achieved by combustion tests. As a next step, a multi-sector combustor with ECF was developed and tested. The test results show that the combustor enables a reduction of 82.2% in LTO NOx emissions relative to the ICAO CAEP/4 standard, though unburnt hydrocarbons (HC) and CO emissions are increased. Temperature distributions in the combustor exit plane were also evaluated.

scholarly journals Emission Reduction of Fuel-Staged Aircraft Engine Combustor Using an Additional Premixed Fuel Nozzle

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Takeshi Yamamoto ◽  
Kazuo Shimodaira ◽  
Seiji Yoshida ◽  
Yoji Kurosawa
Keyword(s):  
Technology Development ◽  
Pressure Ratio ◽  
Aircraft Engine ◽  
Development Project ◽  
Civil Aviation ◽  
Test Results ◽  
Technology Development Project ◽  
Fuel Nozzle ◽  
Conducting Research ◽  
Japan Aerospace Exploration Agency

The Japan Aerospace Exploration Agency (JAXA) is conducting research and development on aircraft engine technologies to reduce environmental impact for the Technology Development Project for Clean Engines (TechCLEAN). As a part of the project, combustion technologies have been developed with an aggressive target that is an 80% reduction over the NOx threshold of the International Civil Aviation Organization (ICAO) Committee on Aviation Environmental Protection (CAEP)/4 standard. A staged fuel nozzle with a pilot mixer and a main mixer was developed and tested using a single-sector combustor under the target engine's landing and takeoff (LTO) cycle conditions with a rated output of 40 kN and an overall pressure ratio of 25.8. The test results showed a 77% reduction over the CAEP/4 NOx standard. However, the reduction in smoke at thrust conditions higher than the 30% MTO condition and of CO emission at thrust conditions lower than the 85% MTO condition are necessary. In the present study, an additional fuel burner was designed and tested with the staged fuel nozzle in a single-sector combustor to control emissions. The test results show that the combustor enables an 82% reduction in NOx emissions relative to the ICAO CAEP/4 standard and a drastic reduction in smoke and CO emissions.

Verification of Low NOx Performance of Simple Primary Rich Combustion Approach by a Newly Established Full Annular Combustor Test Facility

2008 ◽  
Author(s):  
Mitsumasa Makida ◽  
Hideshi Yamada ◽  
Kazuo Shimodaira ◽  
Seiji Yoshida ◽  
Yoji Kurosawa ◽  
...  
Keyword(s):  
Pressure Ratio ◽  
Aircraft Engine ◽  
Test Facility ◽  
Nox Emissions ◽  
Temperature Profiles ◽  
Experimental Facility ◽  
Lean Combustion ◽  
Annular Combustor ◽  
Exit Temperature ◽  
The Rich

In the TechCLEAN project of JAXA, experimental research has been being conducted to develop a combustor for a small aircraft engine (with pressure ratio of about 20). The combustor was tuned to show the behavior of the Rich-Lean combustion through tests under atmospheric and practical conditions. And in 2006, by a designed multi-sector combustor, NOx emissions were reduced to lower than 42% of the ICAO CAEP4 standard. Based on the tuned combustor, full annular combustors were designed. In parallel, an experimental facility to test the full annular combustors under practical conditions was newly constructed in the spring of 2007. The inlet air conditions were set to the ICAO LTO cycle conditions of the target engine; 0.3–1.8MPa for pressure, 400–700K for temperature and 4–18kg/s for air mass flow rate. Through the full annular combustion experiments under practical conditions, the combustors were tuned to keep good combustion performance which was verified by the multi-sector combustors. The optimized full annular combustor finally achieved the following performance; NOx emissions were reduced to lower than 40% of the ICAO CAEP4 standard, maintaining low CO and THC emissions, good exit temperature profiles (P.T.F. = 0.19 at the take-off condition) and good lean blow-out performance (AFR>200 at the idle condition). The process of the optimization is discussed in this report.

Influence of Injection Ratio of Dual-Injection Type Air-Blast Fuel Nozzle on Emission Characteristics Applied to Rectangular Single-Sector Combustor Under Atmospheric Condition

2014 ◽  
Author(s):  
Mitsumasa Makida ◽  
Yoji Kurosawa ◽  
Hideshi Yamada
Keyword(s):  
Fuel Injection ◽  
Atmospheric Condition ◽  
Aircraft Engine ◽  
Inlet Temperature ◽  
Air Blast ◽  
Lean Combustion ◽  
Injection Type ◽  
Fuel Nozzle ◽  
The Rich ◽  
Injection Ratio

In the TechCLEAN project of JAXA, experimental research had been conducted to develop a combustor for a small aircraft engine. The combustor was tuned to show the behavior of the Rich-Lean combustion through tests under atmospheric and practical conditions. Finally, through full annular combustion experiments under practical conditions, the combustor was tuned to reduce NOx emissions to almost 40% of the ICAO CAEP4 standard, also sustaining low CO and THC emissions. In the developing process of above combustors, to simplify the combustor system, air blast type fuel nozzles with single fuel injection and dual swirlers were applied. Successively, in this report, the fuel nozzle is modified to dual fuel injection type with triple swirlers, aiming to control combustion performance under varying load conditions. Fuel is injected from inner and outer injection circuits, and the injection ratio between them is treated as one of the parameters. The combination of swirl direction of the three swirlers is selected at first through ignition and blowout tests. Secondly, spray patterns of the selected fuel nozzle are observed with different fuel injection ratios. Thirdly, the nozzle is applied to a rectangular single-sector combustor, and tested under atmospheric pressure with inlet temperature of 500K. NOx, CO, CO2, THC and O2 compositions in the exhaust gas are measured, and correlation among measured emissions data and fuel injection ratio is estimated to examine the influence of the injection ratio on combustion characteristics of the Rich-Lean type aero engine combustor.

Emission Reduction of Fuel Staged Aircraft Engine Combustor Using an Additional Premixed Fuel Nozzle

2012 ◽  
Author(s):  
Takeshi Yamamoto ◽  
Kazuo Shimodaira ◽  
Seiji Yoshida ◽  
Yoji Kurosawa
Keyword(s):  
Pressure Ratio ◽  
Aircraft Engine ◽  
Test Results ◽  
Drastic Reduction ◽  
Fuel Nozzle ◽  
Conducting Research ◽  
Japan Aerospace Exploration Agency ◽  
Co Emission ◽  
Fuel Burner ◽  
Additional Fuel

The Japan Aerospace Exploration Agency (JAXA) is conducting research and development on aircraft engine technologies to reduce environmental impact for the TechCLEAN project. As a part of the project, combustion technologies have been developed with an aggressive target that is an 80% reduction over the NOx threshold of the ICAO CAEP/4 standard. A staged fuel nozzle with a pilot mixer and a main mixer was developed and tested using a single-sector combustor under the target engine’s LTO cycle conditions with a rated output of 40 kN and an overall pressure ratio of 25.8. The test results showed a 77% reduction over the CAEP/4 NOx standard. A reduction in smoke was found under a higher thrust condition than the 30% MTO condition, and a reduction in CO emission was found under a lower thrust condition than the 85% MTO condition. In the present study, an additional fuel burner was designed and tested with the staged fuel nozzle in a single-sector combustor to control emissions. The test results show that the combustor enables an 82% reduction in NOx emissions relative to the ICAO CAEP/4 standard and a drastic reduction in smoke and CO emissions.

scholarly journals CFD Analysis of Jet Mixing in Low NOx Flametube Combustors

1991 ◽  
Author(s):  
M. V. Talpallikar ◽  
C. E. Smith ◽  
M. C. Lai ◽  
J. D. Holdeman
Keyword(s):  
Aspect Ratio ◽  
High Speed ◽  
Flux Ratio ◽  
Nox Emissions ◽  
Nasa Lewis Research ◽  
Lean Burn ◽  
Jet Mixing ◽  
Critical Technology ◽  
The Rich ◽  
Cfd Analyses

The Rich-burn/Quick-mix/Lean-burn (RQL) combustor has been identified as a potential gas turbine combustor concept to reduce NOx emissions in High Speed Civil Transport (HSCT) aircraft. To demonstrate reduced NOx levels, cylindrical flametube versions of RQL combustors are being tested at NASA Lewis Research Center. A critical technology needed for the RQL combustor is a method of quickly mixing by-pass combustion air with rich-burn gases. In this study, jet mixing in a cylindrical quick-mix section was numerically analyzed. The quick-mix configuration was five inches in diameter and employed twelve radial-inflow slots. The numerical analyses were performed with an advanced, validated 3-D Computational Fluid Dynamics (CFD) code named REFLEQS. Parametric variation of jet-to-mainstream momentum flux ratio (J) and slot aspect ratio was investigated. Both non-reacting and reacting analyses were performed. Results showed mixing and NOx emissions to be highly sensitive to J and slot aspect ratio. Lowest NOx emissions occurred when the dilution jet penetrated to approximately mid-radius. The viability of using 3-D CFD analyses for optimizing jet mixing was demonstrated.

Detailed Research on Rich-Lean Type Single Sector Combustor for Small Aircraft Engine Tested Under Practical Conditions Up to 3MPa

2012 ◽  
Author(s):  
Mitsumasa Makida ◽  
Hideshi Yamada ◽  
Kazuo Shimodaira
Keyword(s):  
Experimental Research ◽  
Aircraft Engine ◽  
Emission Characteristics ◽  
Nox Emissions ◽  
Additional Test ◽  
Lean Combustion ◽  
Test Conditions ◽  
The Rich ◽  
Combustion Tests ◽  
Small Aircraft

In the TechCLEAN project of JAXA, experimental research has been conducted to develop a combustor for a small aircraft engine. The combustor was tuned to show the behavior of the Rich-Lean combustion through tests under atmospheric and practical conditions. Finally, through full annular combustion experiments under practical conditions, the combustor was tuned to reduce NOx emissions to almost 40% of the ICAO CAEP4 standard, also sustaining low CO and THC emissions. To investigate the performance of the combustor in detail, parametric experiments were conducted with single-sector combustors under additional test conditions in addition to design conditions of the target engine. Also the performance as a combustor for higher-efficient aircraft engine is examined by increasing inlet air pressure and temperature up to 3MPa and 825K in combustion tests. Obtained results of emission characteristics are discussed in this report.

Kinetics Modeling on NOx Emissions of a Syngas Turbine Combustor Using Rich-Burn, Quick-Mix, Lean-Burn Combustion Method

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Haoyang Liu ◽  
Wenkai Qian ◽  
Min Zhu ◽  
Suhui Li
Keyword(s):  
Gas Turbine ◽  
Residence Time ◽  
Air Flow ◽  
Outlet Temperature ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Lean Burn ◽  
Kinetics Modeling ◽  
The Rich ◽  
Nox Control

Abstract To avoid flashback issues of the high-H2 syngas fuel, current syngas turbines usually use nonpremixed combustors, which have high NOx emissions. A promising solution to this dilemma is rich-burn, quick-mix, lean-burn (RQL) combustion, which not only reduces NOx emissions but also mitigates flashback. This paper presents a kinetics modeling study on NOx emissions of a syngas–fueled gas turbine combustor using RQL architecture. The combustor was simulated with a chemical reactor network (CRN) model in chemkin-pro software. The combustion and NOx formation reactions were modeled using a detailed kinetics mechanism that was developed for syngas. Impacts of combustor design/operating parameters on NOx emissions were systematically investigated, including combustor outlet temperature, rich/lean air flow split, and residence time split. The mixing effects in both the rich-burn zone and the quick-mix zone were also investigated. Results show that for an RQL combustor, the NOx emissions initially decrease and then increase with combustor outlet temperature. The leading parameters for NOx control are temperature-dependent. At typical modern gas turbine combustor operating temperatures (e.g., <1890 K), the air flow split is the most effective parameter for NOx control, followed by the mixing at the rich-burn zone. However, as the combustor outlet temperature increases, the impacts of air flow split and mixing in the rich-burn zone on NOx reduction become less pronounced, whereas both the residence time split and the mixing in the quick-mix zone become important.

scholarly journals CFD Analysis of Jet Mixing in Low NOx Flametube Combustors

1992 ◽  
Vol 114 (2) ◽  
pp. 416-424 ◽  
Author(s):  
M. V. Talpallikar ◽  
C. E. Smith ◽  
M. C. Lai ◽  
J. D. Holdeman
Keyword(s):  
Aspect Ratio ◽  
High Speed ◽  
Flux Ratio ◽  
Nox Emissions ◽  
Nasa Lewis Research ◽  
Lean Burn ◽  
Jet Mixing ◽  
Critical Technology ◽  
The Rich ◽  
Cfd Analyses

The Rich-burn/Quick-mix/Lean-burn (RQL) combustor has been identified as a potential gas turbine combustor concept to reduce NOx emissions in High Speed Civil Transport (HSCT) aircraft. To demonstrate reduced NOx levels, cylindrical flametube versions of RQL combustors are being tested at NASA Lewis Research Center. A critical technology needed for the RQL combustor is a method of quickly mixing bypass combustion air with rich-burn gases. In this study, jet mixing in a cylindrical quick-mix section was numerically analyzed. The quick-mix configuration was five inches in diameter and employed 12 radial-inflow slots. The numerical analyses were performed with an advanced, validated 3-D Computational Fluid Dynamics (CFD) code named REFLEQS. Parametric varation of jet-to-mainstream momentum flux ratio (J) and slot aspect ratio was investigated. Both nonreacting and reacting analyses were performed. Results showed mixing and NOx emissions to be highly sensitive to J and slot aspect ratio. Lowest NOx emissions occurred when the dilution jet penetrated to approximately midradius. The viability of using 3-D CFD analyses for optimizing jet mixing was demonstrated.

Suppression of NOx Emission of a Lean Staged Combustor for an Aircraft Engine

2011 ◽  
Author(s):  
H. Fujiwara ◽  
K. Matsuura ◽  
K. Shimodaira ◽  
S. Hayashi ◽  
M. Kobayashi ◽  
...  
Keyword(s):  
High Pressure ◽  
Fuel Injection ◽  
Laser Diagnostics ◽  
Pressure Ratio ◽  
Aircraft Engine ◽  
Elevated Pressure ◽  
Nox Emission ◽  
Fuel Spray ◽  
Nox Emissions ◽  
Joint Research

Due to the increasing demands for environment protection, the regulation of NOx emissions from aircraft engines specified by ICAO have become more stringent year by year. A combustor with lean staged fuel injectors is one of the effective methods to reduce NOx emissions. Kawasaki heavy industries Ltd GTBC and Japan Aerospace Exploration Agency (JAXA) have been conducting joint research on a lean staged concentric fuel nozzle for a high pressure ratio aero engine. High pressure combustion tests were performed to clarify the effect of the contour of the air flow passage of the main premix duct, the arrangement of the swilers and the fuel injection position on the NOx emission especially at high power. Visualization of the fuel spray at elevated pressure inside of the premix duct using a model with transparent walls and a laser diagnostics technique showed clear relationship between the distribution of the fuel spray and the NOx emission.

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