Dual Injection Distributed Combustion for Gas Turbine Application

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Ahmed E. E. Khalil ◽  
Ashwani K. Gupta
Keyword(s):  
Gas Turbine ◽  
High Performance ◽  
Fuel Injection ◽  
Scale Up ◽  
Low Noise ◽  
Dual Injection ◽  
Efficient Combustion ◽  
Pollutants Emission ◽  
Improved Performance ◽  
The Impact

Distributed combustion has been shown to provide significantly improved performance with near zero emissions for stationary gas turbine applications. Characteristics of distributed combustion include uniform thermal field in the entire combustion chamber (improved pattern factor), ultra-low emissions of NOx and CO, low noise, enhanced stability, and higher efficiency. Distributed combustion with swirl have been investigated to determine the beneficial aspects of such flows on clean and efficient combustion under simulated gas turbine combustion conditions with ultra-low NOx emissions. Results are presented here on the impact of employing dual injection of air and fuel in contrast to single injection. Dual and multi-injection is of great importance for combustor design scale up as to maintain flow similarities. Results showed that careful implementation of dual injection can result in emissions as low as single air/fuel injection method. With adequate fuel injection strategy, further reduction in emissions has been demonstrated. Results obtained on pollutants emission with dual injection and different fuel injection strategies at various equivalence ratios showed ultra-low emission (<5 PPM NO and <15 PPM CO) and high performance. OH* chemiluminescence revealed relative position of the flame within the combustor under various conditions for further improvements in distributed combustion conditions and to further reduce NOx emission.

Dual Injection Distributed Combustion for Gas Turbine Application

2013 ◽  
Author(s):  
Ahmed E. E. Khalil ◽  
Ashwani K. Gupta
Keyword(s):  
Gas Turbine ◽  
High Performance ◽  
Fuel Injection ◽  
Scale Up ◽  
Low Noise ◽  
Dual Injection ◽  
Efficient Combustion ◽  
Pollutants Emission ◽  
Improved Performance ◽  
The Impact

Distributed Combustion has been shown to provide significantly improved performance with near zero emissions for stationary gas turbine applications. Characteristics of distributed combustion include uniform thermal field in the entire combustion chamber (improved pattern factor), ultra low emissions of NOx and CO, low noise, enhanced stability and higher efficiency. Distributed combustion with swirl have been investigated to determine the beneficial aspects of such flows on clean and efficient combustion under simulated gas turbine combustion conditions with ultra-low NOx emissions. Results are presented here on the impact of employing dual injection of air and fuel in contrast to single injection. Dual and multi injection is of great importance for combustor design scale up as to maintain flow similarities. Results showed that careful implementation of dual injection can result in emissions as low as single air/fuel injection method. With adequate fuel injection strategy, further reduction in emissions has been demonstrated. Results obtained on pollutants emission with dual injection and different fuel injection strategies at various equivalence ratios showed ultra-low emission (<5PPM NO and <15PPM CO) and high performance. OH* chemiluminescence revealed relative position of the flame within the combustor under various conditions for further improvements in distributed combustion conditions and to further reduce NOx emission.

Fuel Flexible Distributed Combustion for Gas Turbine Engines

2012 ◽  
Author(s):  
Ahmed E. E. Khalil ◽  
Ashwani K. Gupta
Keyword(s):  
Gas Turbine ◽  
High Performance ◽  
Low Noise ◽  
Liquid Fuels ◽  
Low Emission ◽  
Wide Range ◽  
Efficient Combustion ◽  
Pollutants Emission ◽  
Significant Performance ◽  
Reduction Of Nox

Distributed Combustion provides significant performance improvement of gas turbine combustors including uniform thermal field in the entire combustion chamber (improved pattern factor), ultra low emission of NOx and CO, low noise, enhanced stability and higher efficiency. Distributed combustion with swirl have been investigated to determine the beneficial aspects of such flows on clean and efficient combustion under simulated gas turbine combustion conditions with close focus on NOx emission. Near Zero emissions of NO and CO have been demonstrated using methane under distributed combustion conditions with heat release intensities commensurable to gas turbine applications. In this paper, distributed combustion is further investigated using both gaseous and liquid fuels with emphasis on pollutants emission and combustor performance with each fuel. Performance evaluation with the different fuels is established to outline the flexibility of the combustor in handling a wide range of fuels with different calorific values and phases with focus on ultra-low pollutants emission. Results obtained on pollutants emission and OH* chemiluminescence for the specific fuels examined at various equivalence ratios are presented. Near distributed combustion conditions with less than 5 PPM of NO emission were demonstrated under novel premixed conditions for the various fuels tested thus outlining the combustor ability to handle different fuels with high performance. Further reduction of NOx can be made with true distributed combustion condition.

Jet Shear Layer Size and Number Influences on Grid Plate Direct Fuel Injection Shear Layer Mixing Low NOx Gas Turbine Combustion With Fuel Staging for Power Turn Down

2008 ◽  
Author(s):  
Gordon E. Andrews ◽  
S. A. R. Ahmed
Keyword(s):  
Shear Layer ◽  
Gas Turbine ◽  
Fuel Injection ◽  
Scale Up ◽  
Shear Layers ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Round Jet ◽  
Fuel Staging ◽  
Four Levels

The scale up of jet shear layer low NOx concepts for compact gas turbine applications is considered using natural gas as the fuel with all experiments at one atmosphere pressure and 600K air inlet temperature. A 76mm diameter cylindrical combustor with 4 round jet shear layers was compared with a near double scale combustor with 140mm diameter and 4 round jet shear layers with the same total blockage as for the smaller combustor. This is compared with 16 round jet shear layers of the same diameter as for the smaller combustor. The shear layer air holes were fuelled by eight radial inward fuel injection holes in each shear layer jet. All three designs had acceptable combustion efficiencies, but the NOx emissions were considerably higher for the 4 shear layer design in the larger combustion. When the same shear layer hole size was used and the number increased in the larger combustor the NOx emissions were identical. Changing the shape of the hole from circulat to slot for the same area, considerably reduced the NOx in the four hole 76mm combustor, but had little effect on the 16 hole 140mm combustor. Fuel staging within the array of shear layers was successfully demonstrated for four levels of fuel staging. There was some intermixing of air from the unfuelled jets, but this had only a small effect on the combustion efficiency and flame stability. A practical range of simulated power turndown was demonstrated with little NOx penalty. This was achieved with no wall between the staged shear layer regions and hence leads to very compact combustor designs.

scholarly journals Implementasi Kebijakan Absensi Biometrik Terhadap Disiplin Dan Kinerja Aparatur Sipil Negara Pada Biro Umum Sekretariat Daerah Provinsi Kalimantan Tengah

2020 ◽  
Vol 7 (1) ◽  
pp. 22-28
Author(s):  
Erry Apriyanti ◽  
Nicodemus Nicodemus ◽  
Milka Milka
Keyword(s):  
Public Policy ◽  
Policy Implementation ◽  
High Performance ◽  
Government Regulation ◽  
Working Environment ◽  
Attendance Policy ◽  
The Hours ◽  
Improved Performance ◽  
And Performance ◽  
The Impact

This research aims to determine the implementation of biometric absence policy and its impact on the discipline and performance of civil state apparatus at the General Bureau of Central Kalimantan Provincial secretariat based on government regulation Number 53 the year 2010 about civil servants ' discipline. This study examined the policy implementation of the researchers using the Model implementation theory of Donald Van Metter and Carl Van Horn's policy (Agustino,2016:133). The Top-Down approach Model in this theory is a performance of a policy implementation that is essentially intentionally done to achieve a high performance implementation of public policy that takes place in a relationship with six Variables that affect the performance of the policy implementation are the size and objectives of policies, resources, the characteristics of implementing agents, attitudes or tendencies (disposition) of executives, communication between organizations and implementing activities and Economic, social and political environment by relying on that policy implementation runs linearly from available political decisions, executor and public policy performance. The type of research used is qualitative descriptive. Data collection techniques use observations, conduct interviews, and documentation, and then data is analyzed by reduction, data presentation and verification. From the results showed that the application of the biometric attendance policy has been performed well this is seen from the improvement of the discipline and performance of ASN which is already meet the hours of entry (morning apple) and hours of office, HR has character Discipline, communication between leaders and subordinates is always established at all times in a level, the working environment shows a conducive atmosphere. The impact of policy implementation of biometrics absent discipline increases and is coupled with improved performance.

Mixture Preparation Effects on Distributed Combustion for Gas Turbine Applications

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Ahmed E. E. Khalil ◽  
Ashwani K. Gupta ◽  
Kenneth M. Bryden ◽  
Sang C. Lee
Keyword(s):  
Gas Turbine ◽  
Fuel Injection ◽  
Hot Spot ◽  
Turbine Blades ◽  
Active Species ◽  
Low Noise ◽  
Spontaneous Ignition ◽  
Air Cooling ◽  
Nox Emissions ◽  
Mixing Process

Distributed combustion is now known to provide significantly improved performance of gas turbine combustors. Key features of distributed combustion include uniform thermal field in the entire combustion chamber for significantly improved pattern factor and avoidance of hot-spot regions that promote thermal NOx emissions, negligible emissions of hydrocarbons and soot, low noise, and reduced air cooling requirements for turbine blades. Distributed combustion requires controlled mixing between the injected air, fuel, and hot reactive gasses from within the combustor prior to mixture ignition. The mixing process impacts spontaneous ignition of the mixture to result in improved distributed combustion reactions. Distributed reactions can be achieved in premixed, partially premixed, or nonpremixed modes of combustor operation with sufficient entrainment of hot and active species present in the combustion zone and their rapid turbulent mixing with the reactants. Distributed combustion with swirl is investigated here to further explore the beneficial aspects of such combustion under relevant gas turbine combustion conditions. The near term goal is to develop a high intensity combustor with ultralow emissions of NOx and CO, and a much improved pattern factor and eventual goal of near zero emission combustor. Experimental results are reported for a cylindrical geometry combustor for different modes of fuel injection with emphasis on the resulting pollutants emission. In all the cases, air was injected tangentially to impart swirl to the flow inside the combustor. Ultra low NOx emissions were found for both the premixed and nonpremixed combustion modes for the geometries investigated here. Results showed very low levels of NO (∼10 ppm) and CO (∼21 ppm) emissions under nonpremixed mode of combustion with air preheats at an equivalence ratio of 0.6 and a moderate heat release intensity of 27 MW/m3-atm. Results are also reported on lean stability limits and OH* chemiluminescence under different fuel injection scenarios for determining the extent of distribution combustion conditions. Numerical simulations have also been performed to help develop an understanding of the mixing process for better understanding of ignition and combustion.

scholarly journals The Role of Fuel Preparation in Low Emissions Combustion

1995 ◽  
Author(s):  
A. H. Lefebvre
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Fuel Injection ◽  
Flame Temperature ◽  
Pollutant Emissions ◽  
Alternative Methods ◽  
Nox Emissions ◽  
Oxides Of Nitrogen ◽  
Lean Burn ◽  
The Impact

The attainment of very low pollutant emissions, in particular oxides of nitrogen (NOx), from gas turbines is not only of considerable environmental concern but has also become an area of increasing competitiveness between the different engine manufacturers. For stationary engines, the attainment of ultra-low NOx has become the foremost marketing issue. This paper is devoted primarily to current and emerging technologies in the development of ultra-low emissions combustors for application to aircraft and stationary engines. Short descriptions of the basic design features of conventional gas turbine combustors and the methods of fuel injection now in widespread use are followed by a review of fuel spray characteristics and recent developments in the measurement and modeling of these characteristics. The main gas turbine generated pollutants and their mechanisms of formation are described, along with related environmental risks and various issues concerning emissions regulations and recently-enacted legislation for limiting the pollutant levels emitted by both aircraft and stationary engines. The impact of these emissions regulations on combustor and engine design are discussed first in relation to conventional combustors and then in the context of variable-geometry and staged combustors. Both these concepts are founded on emissions reduction by control of flame temperature. Basic approaches to the design of “dry” low NOx and ultra-low NOx combustors are reviewed. At the present time lean, premix, prevaporize, combustion appears to be the only technology available for achieving ultra-low NOx emissions from practical combustors. This concept is discussed in some detail, along with its inherent problems of autoignition, flashback, and acoustic resonance. Attention is also given to alternative methods of achieving ultra-low NOx emissions, notably the rich-bum, quick-quench, lean-burn and catalytic combustors. These concepts are now being actively developed, despite the formidable problems they present in terms of mixing and durability. The final section reviews the various correlations which are now being used to predict the exhaust gas concentrations of the main gaseous pollutant emissions from gas turbine engines. Comprehensive numerical methods have not yet completely displaced these semi-empirical correlations but are nevertheless providing useful insight into the interactions of swirling and recirculating flows with fuel sprays, as well as guidance to the combustion engineer during the design and development stages. Throughout the paper emphasis is placed on the important and sometimes pivotal role played by the fuel preparation process in the reduction of pollutant emissions from gas turbines.

scholarly journals Optimal Design and Noise Analysis of High-Performance DBR-Integrated Lateral Germanium (Ge) Photodetectors for SWIR Applications

2021 ◽  
Author(s):  
Harshvardhan Kumar ◽  
Ankit Kumar Pandey ◽  
Chu-Hsuan Lin
Keyword(s):  
Dark Current ◽  
High Speed ◽  
High Performance ◽  
Noise Analysis ◽  
Equivalent Circuit Model ◽  
Low Noise ◽  
Telecommunication Networks ◽  
Bragg Reflector ◽  
Distributed Bragg Reflector ◽  
The Impact

Abstract This work presents the high-performance Si/SiO2distributed Bragg reflector (DBR)-integrated lateral germanium (Ge) p-i-n photodetectors (PDs) for atmospheric gas sensing and fiber-optic telecommunication networks in the short-wave infrared (SWIR) regime. In addition, this study also proposes an opto-electronic compact small-signal noise equivalent circuit model (SSNECM) of the designed device to compute the signal-to-noise ratio (SNR) at the output of the detector. Various figure-of merits including current under dark and illumination, responsivity, detectivity, 3dB bandwidth, and the SNR of the proposed device are estimated at the room-temperature (RT) for an incident optical power of 0.5 μW. Furthermore, the impact of scaling of rib waveguide (WG) width and height on dark current, responsivity, and 3dB bandwidth are investigated to optimize the proposed device. The validation of the proposed model is done by comparing various parameters including dark current, responsivity, and detectivity of the designed device with other Ge PDs. The estimated results show the reduced trade-off between responsivity and 3dB bandwidth of the designed device. At λ=1550 nm, the proposed device achieves the high detectivity and SNR of >2X1011 Jones and 120 dB (up to 3 THz), respectively, with the bias voltage of -2V. These encouraging results pave the path for the future development of low noise and high-speed detectors for SWIR applications.

scholarly journals A Review of Small Gas Turbine Combustion System Development

1979 ◽  
Author(s):  
J. A. Saintsbury ◽  
P. Sampath
Keyword(s):  
Gas Turbine ◽  
Fuel Injection ◽  
System Development ◽  
Turbine Engines ◽  
Reduction Techniques ◽  
Emission Regulations ◽  
Gas Turbine Combustion ◽  
Alternate Source ◽  
Injection Technology ◽  
The Impact

The EPA aircraft emission regulations were promulgated in 1973 and resulted in urgent investigations of many approaches aimed at reducing gas turbine emissions with minimum penalties to normal combustion performance. The impact of this work on small aircraft gas turbine engines is discussed, and emission reduction techniques and data are presented. Unique problems experienced with smaller gas turbine combustion systems are reviewed as are the potential difficulties of developing higher performance small combustors in the future, without the benefit of the complex and costly mechanical approaches which are applicable to the larger engines. The impact of relaxed fuel specifications and alternate-source gas turbine fuels is discussed in terms of altered fuel properties and development of fuel injection technology.

scholarly journals Conditioning and Detailed Analysis of Biomass Derived Fuel Gas Ongoing and Planned Work by Battelle

1999 ◽  
Author(s):  
Don Anson ◽  
Mark A. Paisley ◽  
M. A. Ratcliff
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Low Cost ◽  
Paper Industry ◽  
Scale Up ◽  
Laboratory Scale ◽  
Department Of Energy ◽  
Second Phase ◽  
Fuel Gas ◽  
The Impact

Gas turbine based power and cogeneration schemes are likely to become more favored as turbine efficiencies improve, but the economics of local power generation may depend on the use of low cost fuels other than natural gas. Opportunities may arise in the application of gas turbines in the pulp and paper industry and the wider use of biomass derived fuels in general. These fuels, as produced, typically contain inorganic impurities originating from ash forming substances and other minor constituents of the feedstock. Also, depending on the biomass treatment process, they contain varying amounts of complex organic derivatives, commonly referred to as tars, and some simpler condensable vapors. The Department of Energy is sponsoring work aimed at providing realistic data on low level constituents and impurities in gas derived by indirect gasification of wood, some of which may have disproportionately severe effects on turbine operation, durability, and emissions performance. It is planned to sample gas from both laboratory scale (up to 20 tons/day) and pilot scale (200 tons/day) installations and to assess the effectiveness of wet scrubbing procedures and catalytic reforming of condensables in cleaning up the gases. This paper discusses the rationale for this work, experimental approach, and analytic procedures that will be used. The work will include the operation of a small (220-kWe) gas turbine to provide direct information on the impact of using the final biomass derived gas delivered by the system. The laboratory scale work is currently under way, with a planned completion date in mid 2000. The second phase is dependent on arrangements for integration of the R&D effort with the operation of the pilot plant.

Dietary Vitamin and Stability of Oral Anticoagulation: Proposal of a Diet with Constant Vitamin K1 Content

1997 ◽  
Vol 77 (03) ◽  
pp. 504-509 ◽  
Author(s):  
Sarah L Booth ◽  
Jacqueline M Charnley ◽  
James A Sadowski ◽  
Edward Saltzman ◽  
Edwin G Bovill ◽  
...  
Keyword(s):  
Dietary Intake ◽  
Vitamin K ◽  
High Performance ◽  
Case Reports ◽  
Food Composition ◽  
Dietary Guidelines ◽  
Dietary Vitamin ◽  
Vitamin K1 ◽  
The Stability ◽  
The Impact

SummaryCase reports cited in Medline or Biological Abstracts (1966-1996) were reviewed to evaluate the impact of vitamin K1 dietary intake on the stability of anticoagulant control in patients using coumarin derivatives. Reported nutrient-drug interactions cannot always be explained by the vitamin K1 content of the food items. However, metabolic data indicate that a consistent dietary intake of vitamin K is important to attain a daily equilibrium in vitamin K status. We report a diet that provides a stable intake of vitamin K1, equivalent to the current U.S. Recommended Dietary Allowance, using food composition data derived from high-performance liquid chromatography. Inconsistencies in the published literature indicate that prospective clinical studies should be undertaken to clarify the putative dietary vitamin K1-coumarin interaction. The dietary guidelines reported here may be used in such studies.

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