NOx Reduction in a Swirl Combustor Firing Ammonia for a Micro Gas Turbine

2018 ◽  
Author(s):  
Norihiko Iki ◽  
Osamu Kurata ◽  
Takayuki Matsunuma ◽  
Takahiro Inoue ◽  
Taku Tsujimura ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Nox Reduction ◽  
Nox Removal ◽  
Test Rig ◽  
Regenerative Heat ◽  
Ammonia Gas ◽  
Swirl Combustor ◽  
Micro Gas Turbine ◽  
The Rich ◽  
Removal Equipment

Ammonia is expected to be a hydrogen carrier that has potential as a carbon-free fuel. Ammonia is known as a nonignitable fuel, and it is not easy to hold ammonia flames under atmospheric conditions. A demonstration test with the aim of showing the potential of ammonia-fired power plants was conducted using a micro gas turbine. A 50-kW-class turbine system firing kerosene was selected as a base model. More than 40 kW of power generation was achieved by firing ammonia gas or a mixture of ammonia and methane by modifying the combustor, the fuel control device, and the gas turbine startup sequence. The prototype bifuel combustor is a swirl combustor employing a non-premixed flame and a decreased air flow rate near a gas fuel injector for flame holding. Ammonia combustion in the prototype bifuel combustor was enhanced by supplying hot combustion air and by modifying the air inlets. However, the exhaust gases from the ammonia flames had high NOx concentrations. NOx removal equipment using selective catalytic reduction can reduce NOx emission levels to below 10 ppm from more than 1000 ppm (converted value of NOx to 15% O2) as already reported. However, downsizing of NOx removal equipment should be achieved for practical use. Therefore, a low NOx combustor was developed. As the first step of the development of the combustor, flame observation in the gas turbine combustor was tried. Although the observation area was limited, an inhomogeneous swirling orange flame of ammonia gas was observed. Then, a combustor test rig was prepared for a detailed observation of ammonia flame under various combustion conditions. The combustor test rig used a regenerative heat exchanger for heating combustion air, and it used an orifice for pressure drop instead of a turbine. Combustion air and cooling air were supplied from two air compressors. At startup of the combustor test rig, a spark plug was used to ignite non-premixed methane and air. After heating the regenerative heat exchanger, ammonia gas was supplied to the combustor instead of methane gas. The exhaust gases from the combustor were analyzed using FTIR (Fourier transform infrared spectroscopy) under various conditions, such as methane firing, methane–ammonia firing, and ammonia firing. Although there are several concepts for NOx reduction, a rich–lean combustion method was applied first for ammonia firing. The rich–lean combustor modified from the prototype bifuel combustor also could burn ammonia well in cases of both methane–ammonia firing and ammonia firing. The rich–lean combustor succeeded in reducing NOx emission from methane–ammonia combustion to half the value measured in the case of the prototype bifuel combustor.

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.

scholarly journals A Test Rig for the Experimental Investigation of a MGT/SOFC Hybrid Power Plant Based on a 3kWel Micro Gas Turbine

2019 ◽  
Vol 113 ◽  
pp. 02012
Author(s):  
Martina Hohloch ◽  
Melanie Herbst ◽  
Anna Marcellan ◽  
Timo Lingstädt ◽  
Thomas Krummrein ◽  
...  
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Electrical Power ◽  
Test Rig ◽  
Micro Gas Turbine ◽  
Hybrid Power ◽  
Hybrid Power Plant ◽  
Set Up ◽  
Electrical Power Output

A hybrid power plant consisting of a micro gas turbine (MGT) and a solid oxide fuel cell (SOFC) is a promising technology to reach the demands for future power plants. DLR aims to set up a MGT/SOFC hybrid power plant demonstrator based on a 3 kWel MTT EnerTwin micro gas turbine and an SOFC module with an electrical power output of 30 kWel from Sunfire. For the detailed investigation of the subsystems under hybrid conditions two separate test rigs are set up, one in which the MGT is connected to an emulator of the SOFC and vice versa. The paper introduces the set-up and the functionalities of the MGT based test rig. The special features are highlighted and the possibilities of the cyber physical system for emulation of a hybrid system are explained.

DESIGN OF COMBUSTOR FOR MICRO GAS TURBINE TEST RIG AND ITS PERFORMANCE PREDICTION

2015 ◽  
Vol 77 (8) ◽  
Author(s):  
Feng Xian Tan ◽  
Srithar Rajoo ◽  
Meng Soon Chiong ◽  
Cheng Tung Chong ◽  
Alessandro Romagnoli ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Performance Prediction ◽  
Test Rig ◽  
Fuel Price ◽  
Power Generator ◽  
Micro Gas Turbine ◽  
Backup System ◽  
Range Extender ◽  
Auxiliary Power ◽  
And Performance

Stringent emission rules, air pollution, fluctuation of fuel price and depletion of fossil fuel resources are driving the industry to seek for better alternative of power generation. Micro gas turbine (MGT) provides a promising potential to solve the facing problems. MGT could be used in many applications such as in range extender vehicle, auxiliary power generator, power backup system, combine heat and power system, etc. Combustor plays a very crucial role in MGT system as its performance directly affects the emission quality, power output and fuel consumption of the entire system. This paper demonstrates the literature review, design methodology and performance prediction of the combustor designed for a 14.5kW MGT test rig.

Experimental Investigation of the Performance of a Micro Gas Turbine Fueled With Mixtures of Natural Gas and Biogas

2013 ◽  
Author(s):  
Homam Nikpey ◽  
Mohsen Assadi ◽  
Peter Breuhaus
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Co2 Emissions ◽  
Fuel Mixture ◽  
Combined Heat And Power ◽  
Test Rig ◽  
Heating Value ◽  
Micro Gas Turbine ◽  
Fuel Mixtures ◽  
The Impact

Previously published studies have addressed modifications to the engines when operating with biogas, i.e. a low heating value (LHV) fuel. This study focuses on mapping out the possible biogas share in a fuel mixture of biogas and natural gas in micro combined heat and power (CHP) installations without any engine modifications. This contributes to a reduction in CO2 emissions from existing CHP installations and makes it possible to avoid a costly upgrade of biogas to the natural gas quality as well as engine modifications. Moreover, this approach allows the use of natural gas as a “fallback” solution in the case of eventual variations of the biogas composition and or shortage of biogas, providing improved availability. In this study, the performance of a commercial 100kW micro gas turbine (MGT) is experimentally evaluated when fed by varying mixtures of natural gas and biogas. The MGT is equipped with additional instrumentation, and a gas mixing station is used to supply the demanded fuel mixtures from zero biogas to maximum possible level by diluting natural gas with CO2. A typical biogas composition with 0.6 CH4 and 0.4 CO2 (in mole fraction) was used as reference, and corresponding biogas content in the supplied mixtures was computed. The performance changes due to increased biogas share were studied and compared with the purely natural gas fired engine. This paper presents the test rig setup used for the experimental activities and reports results, demonstrating the impact of burning a mixture of biogas and natural gas on the performance of the MGT. Comparing with when only natural gas was fired in the engine, the electrical efficiency was almost unchanged and no significant changes in operating parameters were observed. It was also shown that burning a mixture of natural gas and biogas contributes to a significant reduction in CO2 emissions from the plant.

Design and Characterization of an Inlet Duct for Mass Flow Measurement in a Micro Gas Turbine Test Rig

2014 ◽  
Author(s):  
C. Buratto ◽  
A. Carandina ◽  
M. Morini ◽  
C. Pavan ◽  
M. Pinelli ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Loss ◽  
Resistive Load ◽  
Test Rig ◽  
Micro Gas Turbine ◽  
Inlet Duct

In this paper, a test rig for experimentation on a micro gas turbine is presented. The test rig consists of a micro gas turbine Solar T-62T-32, which, coupled with a 50 kVA alternator, can supply electrical energy to a calibrated resistive load bank. Particular attention is paid to the design of the inlet duct for the mass flow rate measurement. The basic issue was to create the intake duct for a micro gas turbine (MGT) test rig, in order to provide precise data about the mass flow rate and the thermodynamic air characteristics in the MGT inlet section. The inlet duct is also designed in order to allow future tests on inlet cooling technologies. The MGT is incorporated in a chassis for noise reduction, the dimensions of which are 540 mm (height), 570 mm (width) and 940 mm (length). These small dimensions lead to problems with the insertion of the duct. Moreover, the intake of the compressor is not axial but radial, and this means that a volute must be foreseen to convey the flux into the MGT. Several shapes of volute are analyzed in this paper, considering the effects on the pressure loss and the induction of turbulence. The challenge was to develop a fluid-dynamically efficient duct with the hindrance of a very small available space between the compressor casing, the gearbox and the fuel pipes inside the narrow noise-reduction chassis. The mass flow rate will be computed by means of the differential static pressure between the upstream and the downstream section of a Venturi tube. The choice of a Venturi was due to the fact that it produces a pressure loss lower than any other device, such as orifice plates or other nozzle shapes. Furthermore, the expected mass flow rate would lead to high fluid speeds and, as a consequence, the diameter ratio between the duct and the throat of the Venturi was chosen to be as high as possible.

Operation and Flame Observation of Micro Gas Turbine Firing Ammonia

2017 ◽  
Author(s):  
Norihiko Iki ◽  
Osamu Kurata ◽  
Takayuki Matsunuma ◽  
Takahiro Inoue ◽  
Taku Tsujimura ◽  
...  
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Inlet Temperature ◽  
Exhaust Gas ◽  
No Emission ◽  
Ammonia Gas ◽  
Rotating Speed ◽  
Micro Gas Turbine ◽  
Low Nox Combustion ◽  
Swirling Flames

A demonstration test with the aim to show the potential of ammonia-fired power plant is planned using a micro gas turbine. 50kW class turbine system firing kerosene is selected as a base model. Over 40kW of power generation was achieved by firing ammonia gas only. Over 40kW of power generation was also achieved by firing mixture of ammonia and methane. However ammonia gas supply increases NOx in the exhaust gas dramatically. NOx concentration in the exhaust gas of gas turbine reached at over 600ppm. In the case of the gas turbine operation firing kerosene-ammonia with 31kW of power generation at 75,000rpm of rotating speed, the LHV (Lower Heating Value) ratio of ammonia to the total supplied fuel was changed from 0% to 100% in detail. NO emission increases rapidly to around 400ppm with ammonia at 7% of LHV ratio of ammonia. Then NO emission increases gradually to 600ppm with ammonia at 27% of LHV ratio of ammonia. NO emission has the peak around 60% of LHV ratio of ammonia. NO emission decreases below 500ppm at 100% of LHV ratio of ammonia. The gas turbine operation firing methane-ammonia with 31kW of power generation at 75,000rpm of rotating speed was also tried. NO emission increases rapidly to around 470ppm with ammonia at 7% of LHV ratio of ammonia. Then NO emission increases gradually to 600ppm with ammonia around 30% of LHV ratio of ammonia. NO emission has the peak at 65% of LHV ratio of ammonia. NO emission decreases below 500ppm at 100% of LHV ratio of ammonia. Since the ammonia flame in the prototype combustor seems to be inhomogeneous, ammonia combustion in the prototype combustor may have high NOx region and low NOx region. Therefore there is a possibility of low-NOx combustion. Flame observation was planned to know combustion state for improvement toward the low NOx combustor. Flame observation from the combustor exit was available by extending the combustor exit with the adaptor of the bent coaxial tubes and the quartz window. Swirling flames of ammonia, methane and methane-ammonia were observed near the center axis of the combustor. Flame observation at 39.1kW of power generation was succeeded. In the case of the flame observation, fuel consumption increased due to increase of the heat loss from the combustor. The emissions of NO and NH3 clearly depend on the combustion inlet temperature at 75,000rpm of rotating speed. The emissions of NO and NH3 in the case of the flame observation setting corresponds to the emission in the case of the normal setting at the condition that the power output is 11.2kW lower.

Experimental Investigation of a SOFC/MGT Hybrid Power Plant Test Rig: Impact and Characterization of a Fuel Cell Emulator

2016 ◽  
Author(s):  
Martina Hohloch ◽  
Andreas Huber ◽  
Manfred Aigner
Keyword(s):  
Fuel Cell ◽  
Power Plant ◽  
Gas Turbine ◽  
Electrical Power ◽  
Pressure Vessels ◽  
Test Rig ◽  
Micro Gas Turbine ◽  
Hybrid Power ◽  
Hybrid Power Plant ◽  
Plant Test

The main topic of the paper is the experimental investigation of a solid oxide fuel cell (SOFC) / micro gas turbine (MGT) hybrid power plant test rig. This comprises the proof of concept, the characterization of the operational range and the influence of the coupling on the MGT. The operational concept of the hybrid power plant is designed to reach a maximum flexibility in electrical power output. Therefore the power plant is operated at different MGT shaft speeds and electrical power outputs of the SOFC, thus leading to different SOFC temperatures. Instead of a real fuel cell an emulator was developed and built to emulate the fluid dynamic and thermodynamic behavior of a real SOFC. The test rig is based on a Turbec T100PH micro gas turbine. A specially designed interface connects the facility to the tubing system and the SOFC emulator. For the present investigation the SOFC emulator has been equipped with a gas preheater. It emulates the varying heat output of the fuel cell. The gas preheater is composed of a natural gas combustor based on the FLOX® technology, with a swirl-stabilized pilot stage and allows a wide range of emulating different SOFC outlet temperatures. In addition installations have been integrated into a pressure vessel, representing the SOFC cathode volume, to analyze the increase in residence time and pressure loss. Initially three different configurations of the test rig, no SOFC emulator – tube only, SOFC emulator with pressure vessels and fully equipped SOFC emulator (pressure vessels, installations and gas preheater) are compared regarding the influence of the different volumes, residence times and pressure losses. The operating range of the test rig equipped with gas preheater in cold (no fuel) as well as in hot conditions is investigated. As the velocity at the entrance of the gas turbine combustor increases with increased fuel cell outlet temperature the surge margin is strongly influenced. The operating range was determined for different shaft speeds and preheating (SOFC outlet) temperatures. Finally the transient behavior of the gas preheater and its impact on the MGT is analyzed. The results provide the required basis to implement a cyber physical system, in which the SOFC emulator is controlled by a SOFC model, as well as the basis for the real coupling of MGT and SOFC.

Combustion Simulation of an EGR Operated Micro-Gas Turbine

2008 ◽  
Author(s):  
Maria Cristina Cameretti ◽  
Renzo Piazzesi ◽  
Fabrizio Reale ◽  
Raffaele Tuccillo
Keyword(s):  
Gas Turbine ◽  
Nox Reduction ◽  
Point Of View ◽  
Cfd Analysis ◽  
Micro Gas Turbine ◽  
Recirculation System ◽  
Combustion Simulation ◽  
Nitric Oxide Emissions ◽  
Chemically Reacting ◽  
Micro Turbine

Following their recent experiences in the search of methods for reducing the nitric oxide emissions from a micro-gas turbine, the authors discuss in this paper the results of the combustion simulation under different conditions induced by the activation of an exhaust recirculation system. The theoretical approach starts with a matching analysis of the EGR equipped micro-turbine, and then proceeds with the CFD analysis of the combustor. Different combustion models are compared in order to validate the method for NOx reduction by the point of view of a correct development of the chemically reacting process.

Micro Gas Turbine Based Test Rig for Hybrid System Emulation

2007 ◽  
Author(s):  
Matteo Pascenti ◽  
Mario L. Ferrari ◽  
Loredana Magistri ◽  
Aristide F. Massardo
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Gas Turbine ◽  
Experimental Facility ◽  
Test Rig ◽  
Transient Model ◽  
Micro Gas Turbine ◽  
Preliminary Experimental Data ◽  
Critical Phases ◽  
And Control

The Thermochemical Power Group (TPG) is building at the laboratory of the University of Genoa, Italy, a new high temperature fuel cell - micro gas turbine physical emulator based on commercial machine technology. The aim of this new test rig is the experimental analysis of the coupling of commercial machines with fuel cell stacks focusing the attention on the critical phases of start-up, shutdown and load changes. The experimental facility is composed of a Turbec T100 micro gas turbine package modified for the fuel cell emulator connection, a set of pipes designed for by-pass, measurement or bleed reasons, and a high temperature volume designed for the RRFCS stack dimension physical emulation. This experimental approach is essential for model validations, and to test different transient operative procedures and control systems without any risk for an expensive real fuel cell stack. This paper shows the preliminary experimental data obtained with the machine in stand alone configuration, focusing the attention on the comparison of these results with the tests performed with the external pipes. Furthermore, a theoretical transient model of this new experimental facility has been developed with the TRANSEO tool. It is essential for the rig design and to perform preliminary results necessary to prevent dangerous conditions during the tests. This paper reports a preliminary verification of this model performed with the facility.

Micro Gas Turbine Firing Ammonia

2016 ◽  
Author(s):  
Norihiko Iki ◽  
Osamu Kurata ◽  
Takayuki Matsunuma ◽  
Takahiro Inoue ◽  
Taku Tsujimura ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Catalytic Reduction ◽  
Gas Diffusion ◽  
Diffusion Combustion ◽  
Exhaust Gas ◽  
Ammonia Gas ◽  
Micro Gas Turbine ◽  
New Facility ◽  
Gas Supply

A demonstration test with the aim to show the potential of ammonia-fired power plant is planned using a micro gas turbine. 50kW class turbine system firing kerosene is selected as a base model. A standard combustor is replaced by a prototype combustor which enables a bi fuel supply of kerosene and ammonia gas. Diffusion combustion is employed in the prototype combustor due to its flame stability. Demonstration test firing ammonia gas was achieved using a new facility of large amount of ammonia supply. The gas turbine started firing kerosene and increased its electric power output. After achievement of stable power output, ammonia gas was started to be supplied and its flow rate increased gradually. 41.8kW power output was achieved by firing ammonia gas only. Ammonia gas supply increases NOx in the exhaust gas dramatically. However post-combustion clean-up of the exhaust gas via Selective Catalytic Reduction can reduce NOx successfully.

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