Compact Laser-Based Sensors for Monitoring and Control of Gas Turbine Combustors

Compact Laser-Based Sensors for Monitoring and Control of Gas Turbine Combustors PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781721575411
Category :
Languages : en
Pages : 34

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Book Description
Research is reported on the development of sensors for gas turbine combustor applications that measure real-time gas temperature using near-infrared water vapor absorption and concentration in the combustor exhaust of trace quantities of pollutant NO and CO using mid-infrared absorption. Gas temperature is extracted from the relative absorption strength of two near-infrared transitions of water vapor. From a survey of the water vapor absorption spectrum, two overtone transitions near 1800 nm were selected that can be rapidly scanned in wavelength by injection current tuning a single DFB diode laser. From the ratio of the absorbances on these selected transitions, a path-integrated gas temperature can be extracted in near-real time. Demonstration measurements with this new temperature sensor showed that combustor instabilities could be identified in the power spectrum of the temperature versus time record. These results suggest that this strategy is extremely promising for gas turbine combustor control applications. Measurements of the concentration of NO and CO in the combustor exhaust are demonstrated with mid-infrared transitions using thermo-electrically cooled, quantum cascade lasers operating near 5.26 and 4.62 microns respectively. Measurements of NO are performed in an insulated exhaust duct of a C2H4-air flame at temperatures of approximately 600 K. CO measurements are performed above a rich H2-air flame seeded with CO2 and cooled with excess N2 to 1150 K. Using a balanced ratiometric detection technique a sensitivity of 0.36 ppm-m was achieved for NO and 0.21 ppm-m for CO. Comparisons between measured and predicted water-vapor and CO2 interference are discussed. The mid-infrared laser quantum cascade laser technology is in its infancy; however, these measurements demonstrate the potential for pollutant monitoring in exhaust gases with mid-IR laser absorption. Hanson, Ronald K. and Jeffries, Jay B. Ames Research Center

Compact Laser-Based Sensors for Monitoring and Control of Gas Turbine Combustors

Compact Laser-Based Sensors for Monitoring and Control of Gas Turbine Combustors PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781721575411
Category :
Languages : en
Pages : 34

Get Book Here

Book Description
Research is reported on the development of sensors for gas turbine combustor applications that measure real-time gas temperature using near-infrared water vapor absorption and concentration in the combustor exhaust of trace quantities of pollutant NO and CO using mid-infrared absorption. Gas temperature is extracted from the relative absorption strength of two near-infrared transitions of water vapor. From a survey of the water vapor absorption spectrum, two overtone transitions near 1800 nm were selected that can be rapidly scanned in wavelength by injection current tuning a single DFB diode laser. From the ratio of the absorbances on these selected transitions, a path-integrated gas temperature can be extracted in near-real time. Demonstration measurements with this new temperature sensor showed that combustor instabilities could be identified in the power spectrum of the temperature versus time record. These results suggest that this strategy is extremely promising for gas turbine combustor control applications. Measurements of the concentration of NO and CO in the combustor exhaust are demonstrated with mid-infrared transitions using thermo-electrically cooled, quantum cascade lasers operating near 5.26 and 4.62 microns respectively. Measurements of NO are performed in an insulated exhaust duct of a C2H4-air flame at temperatures of approximately 600 K. CO measurements are performed above a rich H2-air flame seeded with CO2 and cooled with excess N2 to 1150 K. Using a balanced ratiometric detection technique a sensitivity of 0.36 ppm-m was achieved for NO and 0.21 ppm-m for CO. Comparisons between measured and predicted water-vapor and CO2 interference are discussed. The mid-infrared laser quantum cascade laser technology is in its infancy; however, these measurements demonstrate the potential for pollutant monitoring in exhaust gases with mid-IR laser absorption. Hanson, Ronald K. and Jeffries, Jay B. Ames Research Center

Real-Time Optical Fuel-To-Air Ratio Sensor for Gas Turbine Combustors

Real-Time Optical Fuel-To-Air Ratio Sensor for Gas Turbine Combustors PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781721179701
Category :
Languages : en
Pages : 24

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Book Description
The measurement of the temporal distribution of fuel in gas turbine combustors is important in considering pollution, combustion efficiency and combustor dynamics and acoustics. Much of the previous work in measuring fuel distributions in gas turbine combustors has focused on the spatial aspect of the distribution. The temporal aspect however, has often been overlooked, even though it is just as important. In part, this is due to the challenges of applying real-time diagnostic techniques in a high pressure and high temperature environment. A simple and low-cost instrument that non-intrusively measures the real-time fuel-to-air ratio (FAR) in a gas turbine combustor has been developed. The device uses a dual wavelength laser absorption technique to measure the concentration of most hydrocarbon fuels such as jet fuel, methane, propane, etc. The device can be configured to use fiber optics to measure the local FAR inside a high pressure test rig without the need for windows. Alternatively, the device can readily be used in test rigs that have existing windows without modifications. An initial application of this instrument was to obtain time-resolved measurements of the FAR in the premixer of a lean premixed prevaporized (LPP) combustor at inlet air pressures and temperatures as high as 17 atm at 800 K, with liquid JP-8 as the fuel. Results will be presented that quantitatively show the transient nature of the local FAR inside a LPP gas turbine combustor at actual operating conditions. The high speed (kHz) time resolution of this device, combined with a rugged fiber optic delivery system, should enable the realization of a flight capable active-feedback and control system for the abatement of noise and pollutant emissions in the future. Other applications that require an in-situ and time-resolved measurement of fuel vapor concentrations should also find this device to be of use. Nguyen, Quang-Viet and Mongia, Rajiv K. and Dibble, Robert W. Glenn Research Center NASA/TM

ASME 71-GT-63

ASME 71-GT-63 PDF Author: W. R. Lynn
Publisher:
ISBN:
Category : Automotive gas turbines
Languages : en
Pages : 8

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State-of-the-art Laser Gas Sensing Technologies

State-of-the-art Laser Gas Sensing Technologies PDF Author: Yufei Ma
Publisher: MDPI
ISBN: 3039283987
Category : Technology & Engineering
Languages : en
Pages : 278

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Book Description
Trace gas sensing technologies are widely used in many applications, such as environmental monitoring, life science, medical diagnostics, and planetary exploration. On the one hand, laser sources have developed greatly due to the rapid development of laser media and laser techniques in recent years. Some novel lasers such as solid-state, diode, and quantum cascade lasers have experienced significant progress. At present, laser wavelengths can cover the range from ultraviolet to terahertz, which could promote the development of laser gas sensing technologies significantly. On the other hand, some new gas sensing methods have appeared, such as photothermal spectroscopy and photoacoustic spectroscopy. Laser spectroscopy-based gas sensing techniques have the advantages of high sensitivity, non-invasiveness, and allowing in situ, real-time observation. Due to the rapid and recent developments in laser source as well as the great merits of laser spectroscopy-based gas sensing techniques, this book aims to provide an updated overview of the state-of-the-art laser gas sensing technologies.

Diode-laser Absorption Sensor System for Combustion Monitoring and Control Applications

Diode-laser Absorption Sensor System for Combustion Monitoring and Control Applications PDF Author: R. M. Mihalcea
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Development of an Optical Sensor for Active Control of a Gas Turbine Combustor

Development of an Optical Sensor for Active Control of a Gas Turbine Combustor PDF Author: L. Chen
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Applications of Laser-based Diagnostics to High Pressure Rocket and Gas Turbine Combustor Studies

Applications of Laser-based Diagnostics to High Pressure Rocket and Gas Turbine Combustor Studies PDF Author: R. J. Santoro
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Development and Application of Laser-based Sensors for Harsh Combustion Environments

Development and Application of Laser-based Sensors for Harsh Combustion Environments PDF Author: Daniel W. Mattison
Publisher:
ISBN:
Category :
Languages : en
Pages : 316

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LASER STABILIZATION FOR NEAR ZERO NO(subscript X) GAS TURBINE COMBUSTION SYSTEMS.

LASER STABILIZATION FOR NEAR ZERO NO(subscript X) GAS TURBINE COMBUSTION SYSTEMS. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 61

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Book Description
Historically, the development of new industrial gas turbines has been primarily driven by the intent to achieve higher efficiency, lower operating costs and lower emissions. Higher efficiency and lower cost is obtained through higher turbine operating temperatures, while reduction in emissions is obtained by extending the lean operating limit of the combustor. However reduction in the lean stability limit of operation is limited greatly by the chemistry of the combustion process and by the occurrence of thermo-acoustic instabilities. Solar Turbines, CFD Research Corporation, and Los Alamos National Laboratory have teamed to advance the technology associated with laser-assisted ignition and flame stabilization, to a level where it could be incorporated onto a gas turbine combustor. The system being developed is expected to enhance the lean stability limit of the swirl stabilized combustion process and assist in reducing combustion oscillations. Such a system has the potential to allow operation at the ultra-lean conditions needed to achieve NO(subscript x) emissions below 5 ppm without the need of exhaust treatment or catalytic technologies. The research effort was focused on analytically modeling laser-assisted flame stabilization using advanced CFD techniques, and experimentally demonstrating the technology, using a solid-state laser and low-cost durable optics. A pulsed laser beam was used to generate a plasma pool at strategic locations within the combustor flow field such that the energy from the plasma became an ignition source and helped maintain a flame at ultra lean operating conditions. The periodic plasma generation and decay was used to nullify the fluctuations in the heat release from the flame itself, thus decoupling the heat release from the combustor acoustics and effectively reducing the combustion oscillations. The program was built on an existing technology base and includes: extending LANL's existing laser stabilization experience to a sub-scale combustor rig, performing and validating CFD predictions, and ultimately conducting a full system demonstration in a multi-injector combustion system at Solar Turbines.

Multiple Gas Specie Detection Using a Tunable Diode Laser Sensor for Combustion Process Monitoring

Multiple Gas Specie Detection Using a Tunable Diode Laser Sensor for Combustion Process Monitoring PDF Author: William Von Drasek
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :

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