Experimental Characterization of Low NOx Micromix Prototype Combustors for Industrial Gas Turbine Applications

2011 ◽  
Author(s):  
H. H.-W. Funke ◽  
S. Boerner ◽  
W. Krebs ◽  
E. Wolf
Keyword(s):  
Gas Turbine ◽  
Nox Reduction ◽  
High Energy ◽  
Hydrogen Combustion ◽  
Combustion Stability ◽  
Nox Emissions ◽  
Depth Analysis ◽  
Low Nox Combustion ◽  
Industrial Gas Turbine ◽  
Combustion Of Hydrogen

The use of renewable discontinuous energy sources, such as wind- or solar-energy, raises the question of ensuring the continuous demand for energy. For future energy storage scenarios, hydrogen combustion systems play an important role. This offers new opportunities for alternative combustion processes with regard to efficient, safe and low NOx combustion of hydrogen. In addition hydrogen combustion technology will be in need of gas turbine technology for future IGCC power plant concepts. Against the background of ensuring a secure and low NOx combustion of hydrogen, the micromix burning principle is developed since years and was first investigated for the use in aircraft jet engines to significantly reduce NOx-emissions. This combustion principle is based on cross-flow mixing of air and gaseous hydrogen and burns in multiple miniaturized diffusion type flames. The two advantages of this principle are the inherent safety against flash back and the low NOx-emissions due to a very short residence time of reactants in the flame region of the micro-flames. The paper presents an experimental in depth analysis of the combustion principle with regards to low NOx-emissions for higher energy densities. Therefore several geometric variations were investigated and the burning principle was scaled and tested for higher energy densities up to 15 MW/(m2bar). For the different geometries and energy densities, combustion stability, flame anchoring behavior and associated NOx-emissions are tested under preheated atmospheric conditions. The experimental results show the successful scaling of the micromix principle for high energy densities. The general mapping of the test burners demonstrates a wide operating range. Flow phenomena influencing the flame lifting and flame anchoring position with respect to the resulting NOx-emission are analyzed. The investigations highlight further potential for NOx-reduction in industrial gas turbine applications.

Experimental and Numerical Study on Optimizing the Dry Low NOx Micromix Hydrogen Combustion Principle for Industrial Gas Turbine Applications

2016 ◽  
Vol 9 (2) ◽  
Author(s):  
Harald H. W. Funke ◽  
Jan Keinz ◽  
Karsten Kusterer ◽  
Anis Haj Ayed ◽  
Masahide Kazari ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Numerical Study ◽  
Renewable Energy Sources ◽  
Thermal Power ◽  
Flame Structure ◽  
High Energy ◽  
Hydrogen Combustion ◽  
Nox Emissions ◽  
Fuel Injectors ◽  
The Impact

Combined with the use of renewable energy sources for its production, hydrogen represents a possible alternative gas turbine fuel for future low-emission power generation. Due to the difference in the physical properties of hydrogen compared to other fuels such as natural gas, well-established gas turbine combustion systems cannot be directly applied to dry low NOx (DLN) hydrogen combustion. The DLN micromix combustion of hydrogen has been under development for many years, since it has the promise to significantly reduce NOx emissions. This combustion principle for air-breathing engines is based on crossflow mixing of air and gaseous hydrogen. Air and hydrogen react in multiple miniaturized diffusion-type flames with an inherent safety against flashback and with low NOx emissions due to a very short residence time of the reactants in the flame region. The paper presents an advanced DLN micromix hydrogen application. The experimental and numerical study shows a combustor configuration with a significantly reduced number of enlarged fuel injectors with high-thermal power output at constant energy density. Larger fuel injectors reduce manufacturing costs, are more robust and less sensitive to fuel contamination and blockage in industrial environments. The experimental and numerical results confirm the successful application of high-energy injectors, while the DLN micromix characteristics of the design point, under part-load conditions, and under off-design operation are maintained. Atmospheric test rig data on NOx emissions, optical flame-structure, and combustor material temperatures are compared to numerical simulations and show good agreement. The impact of the applied scaling and design laws on the miniaturized micromix flamelets is particularly investigated numerically for the resulting flow field, the flame-structure, and NOx formation.

Premixing Gas and Air to Reduce NOx Emissions With Existing Proven Gas Turbine Combustion Chambers

1986 ◽  
Author(s):  
B. Becker ◽  
P. Berenbrink ◽  
H. Brandner
Keyword(s):  
Gas Turbine ◽  
Nox Reduction ◽  
Combustion Process ◽  
Liquid Fuels ◽  
Nox Emissions ◽  
Combustion Chambers ◽  
Load Range ◽  
Usual Manner ◽  
Low Nox Combustion ◽  
Gas Turbine Combustion

In the case of the burners employed in KWU gas turbine combustion chambers, the entire primary air is supplied through the swirlers associated with the burners. It is thus relatively easy to add natural gas to this air uniformly before it enters the combustion zone. This results in a particularly low NOx combustion process provided that the air to fuel ratio is being maintained within a certain range. The supplementary equipment to premix the fuel and air does not affect the burner performance when the fuel is supplied in the conventional way by means of gas or oil nozzles. Consequently, the gas turbine will be started up and loaded in the usual manner. In the high load range the burners are then switched over to premixed combustion operation. A small amount of fuel through the central gas nozzle stabilizes the flame in the case of a sudden load decrease. Combustion chambers already in service can be retrofitted with the new premixing equipment to reduce NOx emissions to about one third of the original values. The combustors can be operated with liquid fuels together with steam or water for NOx reduction in the conventional way.

Numerical and Experimental Characterization of Low NOx Micromix Combustion Principle for Industrial Hydrogen Gas Turbine Applications

2012 ◽  
Author(s):  
H. H.-W. Funke ◽  
S. Boerner ◽  
J. Keinz ◽  
K. Kusterer ◽  
D. Kroniger ◽  
...  
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Momentum Flux ◽  
Cross Flow ◽  
Nox Emissions ◽  
Atmospheric Conditions ◽  
Flow Mixing ◽  
Low Nox Combustion ◽  
Combustion Of Hydrogen

The international effort to reduce the environmental impact of electricity generation, especially CO2-emissions requires considerations about alternative energy supply systems. An effective step towards low pollution power generation is the application of hydrogen as a possible alternative gas turbine fuel, if the hydrogen is produced by renewable energy sources, such as wind energy or biomass. The use of hydrogen and hydrogen rich gases as a fuel for industrial applications and power generation combined with the control of polluted emissions, especially NOx, is a major key driver in the design of future gas turbine combustors. The micromix combustion principle allows a secure and low NOx combustion of hydrogen and air and achieves a significant reduction of NOx-emissions. The combustion principle is based on cross-flow mixing of air and gaseous pure hydrogen and burns in multiple miniaturized diffusion-type flames. For the characterization of the jet in cross-flow mixing process, the momentum flux ratio is used. The paper presents an experimental analysis of the momentum flux ratio’s impact on flame anchoring and on the resultant formation of the NOx-emissions. Therefore several prototype test burner with different momentum flux ratios are tested under preheated atmospheric conditions. The investigation shows that the resultant positioning and anchoring of the micro flames highly influences the NOx-formation. Besides the experimental investigations, numerical simulations have been performed by the application of a commercial CFD code. The cold flow simulation results show the mixing of the air and hydrogen after the injection, in particular in the Counter Rotating Vortices (CRV). Furthermore, the hydrogen jet interacts also with another vortex system resulting from a wake flow area behind the combustor geometry. Furthermore, reacting flow simulations have been performed by the application of a Hybrid Eddy Break-Up (EBU) combustion model. The combustion pressure has been varied from atmospheric conditions up to a pressure of 16 bar. The experimental and numerical results highlight further potential of the micromix combustion principle for low NOx-combustion of hydrogen in industrial gas turbine applications.

Experimental and Numerical Study on Optimizing the DLN Micromix Hydrogen Combustion Principle for Industrial Gas Turbine Applications

2015 ◽  
Author(s):  
H. H.-W. Funke ◽  
J. Keinz ◽  
K. Kusterer ◽  
A. Haj Ayed ◽  
M. Kazari ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Numerical Study ◽  
Renewable Energy Sources ◽  
Thermal Power ◽  
Flame Structure ◽  
High Energy ◽  
Hydrogen Combustion ◽  
Nox Emissions ◽  
Fuel Injectors ◽  
The Impact

Combined with the use of renewable energy sources for its production, hydrogen represents a possible alternative gas turbine fuel for future low emission power generation. Due to the difference in the physical properties of hydrogen compared to other fuels such as natural gas, well-established gas turbine combustion systems cannot be directly applied to Dry Low NOx (DLN) hydrogen combustion. The DLN Micromix combustion of hydrogen has been under development for many years, since it has the promise to significantly reduce NOx emissions. This combustion principle for air-breathing engines is based on cross-flow mixing of air and gaseous hydrogen. Air and hydrogen react in multiple miniaturized diffusion-type flames with an inherent safety against flash-back and with low NOx-emissions due to a very short residence time of the reactants in the flame region. The paper presents an advanced DLN Micromix hydrogen application. The experimental and numerical study shows a combustor configuration with a significantly reduced number of enlarged fuel injectors with high thermal power output at constant energy density. Larger fuel injectors reduce manufacturing costs, are more robust and less sensitive to fuel contamination and blockage in industrial environments. The experimental and numerical results confirm the successful application of high energy injectors, while the DLN Micromix characteristics of the design point, under part load conditions and under off-design operation are maintained. Atmospheric test rig data on NOx emissions, optical flame structure and combustor material temperatures are compared to numerical simulations and show good agreement. The impact of the applied scaling and design laws on the miniaturized Micromix flamelets is particularly investigated numerically for the resulting flow field, the flame structure and NOx formation.

Field Conversion of a Low-Firing Frame 7B Gas Turbine Power Plant to Ultra-Low Emission Combustion

2015 ◽  
Author(s):  
Nicolas Demougeot ◽  
Jeffrey A. Benoit
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Energy Demand ◽  
Water Injection ◽  
Cost Benefit ◽  
High Energy ◽  
Nox Emissions ◽  
Environmental Controls ◽  
Low Emission ◽  
Technical Discussion

The search for power plant sustainability options continues as regulating agencies exert more stringent industrial gas turbine emission requirements on operators. Purchasing power for resale, de-commissioning current capabilities altogether and repowering by replacing or converting existing equipment to comply with emissions standards are economic-driven options contemplated by many mature gas turbine operators. NRG’s Gilbert power plant based in Milford, NJ began commercial operation in 1974 and is fitted with four (4) natural gas fired GE’s 7B gas turbine generators with two each exhausting to HRSG’s feeding one (1) steam turbine generator. The gas turbine units, originally configured with diffusion flame combustion systems with water injection, were each emitting 35 ppm NOx with the New Jersey High Energy Demand Day (HEED) regulatory mandate to reduce NOx emissions to sub 10 ppm by May 1st, 2015. Studies were conducted by the operator to evaluate the economic viability & installation of environmental controls to reduce NOx emissions. It was determined that installation of post-combustion environmental controls at the facility was both cost prohibitive and technically challenging, and would require a fundamental reconfiguration of the facility. Based on this economic analysis, the ultra-low emission combustion system conversion package was selected as the best cost-benefit solution. This technical paper will focus on the ultra low emissions technology and key features employed to achieve these low emissions, a description of the design challenges and solution to those, a summary of the customer considerations in down selecting options and an overview of the conversion scope. Finally, a technical discussion of the low emissions operational flexibility will be provided including performance results of the converted units.

A NOx Reduction Project for a GT11 Type Gas Turbine

2005 ◽  
Author(s):  
Lars O. Nord ◽  
David R. Schoemaker ◽  
Helmer G. Andersen
Keyword(s):  
Power Plant ◽  
Distribution System ◽  
Gas Turbines ◽  
Nox Reduction ◽  
Measurement Data ◽  
Combustion Stability ◽  
Study Phase ◽  
Nox Emissions ◽  
Ambient Conditions ◽  
Exhaust Temperature

A study was initiated to investigate the possibility of significantly reducing the NOx emissions at a power plant utilizing, among other manufacturers, ALSTOM GT11 type gas turbines. This study is limited to one of the GT11 type gas turbines on the site. After the initial study phase, the project moved on to a mechanical implementation stage, followed by thorough testing and tuning. The NOx emissions were to be reduced at all ambient conditions, but particularly at cold conditions (below 0°C) where a NOx reduction of more than 70% was the goal. The geographical location of the power plant means cold ambient conditions for a large part of the year. The mechanical modifications included the addition of Helmholtz damper capacity with an approximately 30% increase in volume for passive thermo-acoustic instability control, significant piping changes to the fuel distribution system in order to change the burner configuration, and installation of manual valves for throttling of the fuel gas to individual burners. Subsequent to the mechanical modifications, significant time was spent on testing and tuning of the unit to achieve the wanted NOx emissions throughout a major part of the load range. The tuning was, in addition to the main focus of the NOx reduction, also focused on exhaust temperature spread, combustion stability, CO emissions, as well as other parameters. The measurement data was acquired through a combination of existing unit instrumentation and specific instrumentation added to aid in the tuning effort. The existing instrumentation readings were polled from the control system. The majority of the added instrumentation was acquired via the FieldPoint system from National Instruments. The ALSTOM AMODIS plant-monitoring system was used for acquisition and analysis of all the data from the various sources. The project was, in the end, a success with low NOx emissions at part load and full load. As a final stage of the project, the CO emissions were also optimized resulting in a nice compromise between the important parameters monitored, namely NOx emissions, CO emissions, combustion stability, and exhaust temperature distribution.

Comparison of Numerical Combustion Models for Hydrogen and Hydrogen-Rich Syngas Applied for Dry-Low-NOx-Micromix-Combustion

2016 ◽  
Author(s):  
H. H.-W. Funke ◽  
N. Beckmann ◽  
J. Keinz ◽  
S. Abanteriba
Keyword(s):  
Reaction Mechanism ◽  
Gas Turbines ◽  
Combustion Process ◽  
Computational Effort ◽  
Hydrogen Combustion ◽  
Combustion Stability ◽  
Research Approach ◽  
Pure Hydrogen ◽  
Nox Emissions ◽  
Combustion Models

The Dry-Low-NOx (DLN) Micromix combustion technology has been developed as low emission combustion principle for industrial gas turbines fueled with hydrogen or syngas. The combustion process is based on the phenomenon of jet-in-crossflow-mixing. Fuel is injected perpendicular into the air-cross-flow and burned in a multitude of miniaturized, diffusion-like flames. The miniaturization of the flames leads to a significant reduction of NOx emissions due to the very short residence time of reactants in the flame. In the Micromix research approach, CFD analyses are validated towards experimental results. The combination of numerical and experimental methods allows an efficient design and optimization of DLN Micromix combustors concerning combustion stability and low NOx emissions. The paper presents a comparison of several numerical combustion models for hydrogen and hydrogen-rich syngas. They differ in the complexity of the underlying reaction mechanism and the associated computational effort. For pure hydrogen combustion a one-step global reaction is applied using a hybrid Eddy-Break-up model that incorporates finite rate kinetics. The model is evaluated and compared to a detailed hydrogen combustion mechanism derived by Li et al. including 9 species and 19 reversible elementary reactions. Based on this mechanism, reduction of the computational effort is achieved by applying the Flamelet Generated Manifolds (FGM) method while the accuracy of the detailed reaction scheme is maintained. For hydrogen-rich syngas combustion (H2-CO) numerical analyses based on a skeletal H2/CO reaction mechanism derived by Hawkes et al. and a detailed reaction mechanism provided by Ranzi et al. are performed. The comparison between combustion models and the validation of numerical results is based on exhaust gas compositions available from experimental investigation on DLN Micromix combustors. The conducted evaluation confirms that the applied detailed combustion mechanisms are able to predict the general physics of the DLN-Micromix combustion process accurately. The Flamelet Generated Manifolds method proved to be generally suitable to reduce the computational effort while maintaining the accuracy of detailed chemistry. Especially for reaction mechanisms with a high number of species accuracy and computational effort can be balanced using the FGM model.

Combustor Development and Engine Demonstration of Micro-Mix Hydrogen Combustion Applied to M1A-17 Gas Turbine

2021 ◽  
Author(s):  
Atsushi Horikawa ◽  
Kunio Okada ◽  
Masato Yamaguchi ◽  
Shigeki Aoki ◽  
Manfred Wirsum ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Electrical Power ◽  
Hydrogen Combustion ◽  
Hydrogen Gas ◽  
Air Pollution Control ◽  
Production Of Hydrogen ◽  
Fuel Staging ◽  
Power Generation Plant ◽  
Electrical Power Output ◽  
Industrial Gas Turbine

Abstract Kawasaki Heavy Industries, LTD. (KHI) has research and development projects for a future hydrogen society. These projects comprise the complete hydrogen cycle, including the production of hydrogen gas, the refinement and liquefaction for transportation and storage, and finally the utilization in a gas turbine for electricity and heat supply. Within the development of the hydrogen gas turbine, the key technology is stable and low NOx hydrogen combustion, namely the Dry Low NOx (DLN) hydrogen combustion. KHI, Aachen University of Applied Science, and B&B-AGEMA have investigated the possibility of low NOx micro-mix hydrogen combustion and its application to an industrial gas turbine combustor. From 2014 to 2018, KHI developed a DLN hydrogen combustor for a 2MW class industrial gas turbine with the micro-mix technology. Thereby, the ignition performance, the flame stability for equivalent rotational speed, and higher load conditions were investigated. NOx emission values were kept about half of the Air Pollution Control Law in Japan: 84ppm (O2-15%). Hereby, the elementary combustor development was completed. From May 2020, KHI started the engine demonstration operation by using an M1A-17 gas turbine with a co-generation system located in the hydrogen-fueled power generation plant in Kobe City, Japan. During the first engine demonstration tests, adjustments of engine starting and load control with fuel staging were investigated. On 21st May, the electrical power output reached 1,635 kW, which corresponds to 100% load (ambient temperature 20 °C), and thereby NOx emissions of 65 ppm (O2-15, 60 RH%) were verified. Here, for the first time, a DLN hydrogen-fueled gas turbine successfully generated power and heat.

Experimental Assessment of the Emissions Benefits of a Ceramic Gas Turbine Combustor

1996 ◽  
Author(s):  
K. O. Smith ◽  
A. Fahme
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Flow Distribution ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Experimental Assessment ◽  
Industrial Gas Turbine ◽  
Combustor Liner

Three subscale, cylindrical combustors were rig tested on natural gas at typical industrial gas turbine operating conditions. The intent of the testing was to determine the effect of combustor liner cooling on NOx and CO emissions. In order of decreasing liner cooling, a metal louvre-cooled combustor, a metal effusion-cooled combustor, and a backside-cooled ceramic (CFCC) combustor were evaluated. The three combustors were tested using the same lean-premixed fuel injector. Testing showed that reduced liner cooling produced lower CO emissions as reaction quenching near the liner wall was reduced. A reduction in CO emissions allows a reoptimization of the combustor air flow distribution to yield lower NOx emissions.

Kinetics Modeling on NOx Emissions of a Syngas Turbine Combustor Using RQL Combustion Method

2019 ◽  
Author(s):  
Haoyang Liu ◽  
Wenkai Qian ◽  
Min Zhu ◽  
Suhui Li
Keyword(s):  
Gas Turbine ◽  
Residence Time ◽  
Air Flow ◽  
Nox Reduction ◽  
Outlet Temperature ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Kinetics Modeling ◽  
The Rich ◽  
Nox Control

Abstract To avoid flashback issues of the high-H2 syngas fuel, current syngas turbines usually use non-premixed combustors, which have high NOx emissions. A promising solution to this dilemma is RQL (rich-burn, quick-mix, lean-burn) 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 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.

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