Intelligent Operation of Siemens (SGT-300) DLE Gas Turbine Combustion System Over an Extended Fuel Range With Low Emissions

2011 ◽  
Author(s):  
Ghenadie Bulat ◽  
Kexin Liu ◽  
Gavin Brickwood ◽  
Victoria Sanderson ◽  
Brian Igoe
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Intelligent Control ◽  
Control Algorithm ◽  
Landfill Gas ◽  
Stable Operation ◽  
Nox Emissions ◽  
Single Digit ◽  
Engine Operation ◽  
Wobbe Index

The use of an innovative, intelligent control algorithm applied to the Siemens SGT-300 DLE engine is described. The algorithm ensures stable operation and minimises emissions over a wide variation in fuel composition. The Siemens 8MW class SGT-300 gas turbine has been in operation at the University of New Hampshire (USA) since 2006. As well as operating on natural gas or diesel, the engine also operates on a gas processed from a landfill. These gases have a variable Wobbe Index (WI) covering the range 29.7 to 49 MJ/m3. No modifications have been required to the standard DLE combustion hardware. Introduction of the intelligent control algorithm has been instrumental in achieving this tri-fuel capability. Accumulation of more than 10 000 hours running on non-standard fuel has been achieved. The intelligent control algorithm exploits knowledge of the stable operating window through continual modification of the fuel schedule to avoid both lean blow out and high metal temperatures. Operationally, this results in a reduction in the NOx emissions, through controlling the unmixedness, and higher engine reliability, through the response of the algorithm to flame stability. Combining these advantages the control algorithm can deliver reliable engine operation on variable composition fuels when using standard combustion hardware achieving single digit NOx emissions not only on natural gas but also on processed landfill gas. This paper describes the control algorithm and presents results of the development from high pressure combustion rig and engine development test to field operation with both natural gas and processed landfill gas.

Application of Thermal Oxidation to a Recuperated Gas Turbine: The Path to PPB NOx Emissions

2013 ◽  
Author(s):  
Jeffrey Armstrong ◽  
Douglas Hamrin ◽  
Steve Lampe
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Fuel Injection ◽  
Landfill Gas ◽  
Premixed Combustion ◽  
Nox Emissions ◽  
Single Digit ◽  
Lean Premixed Combustion ◽  
Lean Premixed ◽  
Order Of Magnitude

Dry, low NOx emissions developments in the industrial gas turbine industry have focused on lean-premixed combustion to reduce NOx to single digit parts-per-million (ppmV) emissions. The reduction of thermal NOx is limited by the lowest lean-premix combustion temperatures. To overcome this limit, a thermal oxidizer is applied which can oxidize hydrocarbon fuels at temperatures below those of lean-premixed combustion in a Brayton cycle. This oxidation technique is explained in a combustion taxonomy model. This paper presents the historical development and demonstration of technology with two different recuperated gas turbines operating on landfill gas. A unique fuel-injection strategy was used to introduce the fuel into the inlet of the gas turbine’s air compressor. The technology demonstrated an order-of-magnitude reduction in the emissions of NOx to the parts-per-billion range.

Performance Prediction of Gas Turbine Under Different Strategies Using Low Heating Value Fuel

2013 ◽  
Author(s):  
Edson Batista da Silva ◽  
Marcelo Assato ◽  
Rosiane Cristina de Lima
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Equivalence Ratio ◽  
Safe Operation ◽  
Engine Operation ◽  
Heating Value ◽  
Gasification Process ◽  
Surge Margin ◽  
And Performance ◽  
Industrial Gas Turbine

Usually, the turbogenerators are designed to fire a specific fuel, depending on the project of these engines may be allowed the operation with other kinds of fuel compositions. However, it is necessary a careful evaluation of the operational behavior and performance of them due to conversion, for example, from natural gas to different low heating value fuels. Thus, this work describes strategies used to simulate the performance of a single shaft industrial gas turbine designed to operate with natural gas when firing low heating value fuel, such as biomass fuel from gasification process or blast furnace gas (BFG). Air bled from the compressor and variable compressor geometry have been used as key strategies by this paper. Off-design performance simulations at a variety of ambient temperature conditions are described. It was observed the necessity for recovering the surge margin; both techniques showed good solutions to achieve the same level of safe operation in relation to the original engine. Finally, a flammability limit analysis in terms of the equivalence ratio was done. This analysis has the objective of verifying if the combustor will operate using the low heating value fuel. For the most engine operation cases investigated, the values were inside from minimum and maximum equivalence ratio range.

Lean Blowout Limit and NOx-Production of a Premixed Sub-ppm NOx Burner With Periodic Flue Gas Recirculation

2004 ◽  
Author(s):  
Jochen R. Kalb ◽  
Thomas Sattelmayer
Keyword(s):  
Natural Gas ◽  
Flue Gas ◽  
Gas Content ◽  
Stable Operation ◽  
Reacting Flow ◽  
Nox Emissions ◽  
Lean Blowout ◽  
Fresh Mixture ◽  
Flue Gas Recirculation ◽  
Gas Recirculation

The technological objective of this work is the development of a lean-premixed burner for natural gas. Sub-ppm NOx emissions can be accomplished by shifting the lean blowout limit (LBO) to slightly lower adiabatic flame temperatures than the LBO of current standard burners. This can be achieved with a novel burner concept utilizing periodic flue gas recirculation: Hot flue gas is admixed to the injected premixed fresh mixture with a mass flow rate of comparable magnitude, in order to achieve self-ignition. The subsequent combustion of the diluted mixture again delivers flue gas. A fraction of the combustion products is then admixed to the next stream of fresh mixture. This process pattern is to be continued in a cyclically closed topology, in order to achieve stable combustion of e.g. natural gas in a temperature regime of very low NOx production. The principal ignition behavior and NOx production characteristics of one sequence of the periodic process was modeled by an idealized adiabatic system with instantaneous admixture of partially or completely burnt flue gas to one stream of fresh reactants. With the CHEMKIN-II package a reactor network consisting of one perfectly stirred reactor (PSR, providing ignition in the first place) and two plug flow reactors (PFR) has been used. The effect of varying burnout and the influence of the fraction of admixed flue gas have been evaluated. The simulations have been conducted with the reaction mechanism of Miller and Bowman and the GRI-Mech 3.0 mechanism. The results show that the high radical content of partially combusted products leads to a massive decrease of the time required for the formation of the radical pool. As a consequence, self-ignition times of 1 ms are achieved even at adiabatic flame temperatures of 1600 K and less, if the flue gas content is about 50%–60% of the reacting flow after mixing is complete. Interestingly, the effect of radicals on ignition is strong, outweighs the temperature deficiency and thus allows stable operation at very low NOx emissions.

Impact of Ethane, Propane, and Diluent Content in Natural Gas on the Performance of a Commercial Microturbine Generator

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Richard L. Hack ◽  
Vincent G. McDonell
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Fuel Composition ◽  
Nox Emissions ◽  
Heating Value ◽  
Designed Experiment ◽  
Methane Number ◽  
The Impact ◽  
Lean Conditions

The impact of fuel composition on the performance of power generation devices is gaining interest as the desire to diversify fuel supplies increases. In the present study, measurements of combustion performance were conducted on a commercial natural gas-fired 60kW gas turbine as a function of fuel composition. A statistically designed experiment was carried out and exhaust emissions were obtained for significant amounts of ethane and propane. In addition, a limited study of the effect of inerts was conducted. The results show that emissions of NOx, CO, and NOx∕NO are not well correlated with common descriptions of the fuel, such as higher heating value or methane number. The results and trends indicate that the presence of higher hydrocarbons in the fuel leads to appreciably higher NOx emissions for both test devices operating under similar lean conditions, while having less impact on CO emissions.

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.

Fuel Interchangeability for Lean Premixed Combustion in Gas Turbine Engines

2008 ◽  
Author(s):  
Don Ferguson ◽  
Geo. A. Richard ◽  
Doug Straub
Keyword(s):  
Natural Gas ◽  
Dynamic Response ◽  
Gas Turbine ◽  
Turbine Engines ◽  
Nox Emissions ◽  
Gas Turbine Engines ◽  
Lean Premixed Combustion ◽  
Combustion Dynamics ◽  
Rijke Tube ◽  
Fuel Blends

In response to environmental concerns of NOx emissions, gas turbine manufacturers have developed engines that operate under lean, pre-mixed fuel and air conditions. While this has proven to reduce NOx emissions by lowering peak flame temperatures, it is not without its limitations as engines utilizing this technology are more susceptible to combustion dynamics. Although dependent on a number of mechanisms, changes in fuel composition can alter the dynamic response of a given combustion system. This is of particular interest as increases in demand of domestic natural gas have fueled efforts to utilize alternatives such as coal derived syngas, imported liquefied natural gas and hydrogen or hydrogen augmented fuels. However, prior to changing the fuel supply end-users need to understand how their system will respond. A variety of historical parameters have been utilized to determine fuel interchangeability such as Wobbe and Weaver Indices, however these parameters were never optimized for today’s engines operating under lean pre-mixed combustion. This paper provides a discussion of currently available parameters to describe fuel interchangeability. Through the analysis of the dynamic response of a lab-scale Rijke tube combustor operating on various fuel blends, it is shown that commonly used indices are inadequate for describing combustion specific phenomena.

Lean Blowout Limit and NOx Production of a Premixed Sub-ppm NOx Burner With Periodic Recirculation of Combustion Products

2004 ◽  
Vol 128 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Jochen R. Kalb ◽  
Thomas Sattelmayer
Keyword(s):  
Natural Gas ◽  
Flue Gas ◽  
Combustion Products ◽  
Gas Content ◽  
Stable Operation ◽  
Reacting Flow ◽  
Nox Emissions ◽  
Current Standard ◽  
Lean Blowout ◽  
Fresh Mixture

The technological objective of this work is the development of a lean-premixed burner for natural gas. Sub-ppm NOx emissions can be accomplished by shifting the lean blowout limit (LBO) to slightly lower adiabatic flame temperatures than the LBO of current standard burners. This can be achieved with a novel burner concept utilizing spatially periodic recirculation of combustion products: Hot combustion products are admixed to the injected premixed fresh mixture with a mass flow rate of comparable magnitude, in order to achieve self-ignition. The subsequent combustion of the diluted mixture again delivers products. A fraction of these combustion products is then admixed to the next stream of fresh mixture. This process pattern is to be continued in a cyclically closed topology, in order to achieve stable combustion of, for example, natural gas in a temperature regime of very low NOx production. The principal ignition behavior and NOx production characteristics of one sequence of the periodic process was modeled by an idealized adiabatic system with instantaneous admixture of partially or completely burnt combustion products to one stream of fresh reactants. With the CHEMKIN-II package, a reactor network consisting of one perfectly stirred reactor (PSR, providing ignition in the first place) and two plug flow reactors (PFR) has been used. The effect of varying burnout and the influence of the fraction of admixed flue gas has been evaluated. The simulations have been conducted with the reaction mechanism of Miller and Bowman and the GRI-Mech 3.0 mechanism. The results show that the high radical content of partially combusted products leads to a massive decrease of the time required for the formation of the radical pool. As a consequence, self-ignition times of 1 ms are achieved even at adiabatic flame temperatures of 1600 K and less, if the flue gas content is about 50–60% of the reacting flow after mixing is complete. Interestingly, the effect of radicals on ignition is strong, outweighs the temperature deficiency and thus allows stable operation at very low NOx emissions.

Properties of Artificial Gaseous Mixtures for their Safe Use and Support the Natural Gas Supply Networks / Własności Sztucznych Mieszanin Gazowych do Bezpiecznego ich Użytkowania i Wspomagania Zasilania Sieci Gazu Ziemnego

2012 ◽  
Vol 57 (2) ◽  
pp. 351-362 ◽  
Author(s):  
Mariusz Łaciak
Keyword(s):  
Heat Exchange ◽  
Natural Gas ◽  
Landfill Gas ◽  
Gas Mixtures ◽  
Gaseous Mixtures ◽  
Household Appliances ◽  
The World ◽  
Wobbe Index ◽  
Gas Supply

Abstract The increase in natural gas consumption by the general public and industry development, in particular the petrochemical and chemical industries, has made increasing the world interest in using gas replacement for natural gas, both as mixtures of flammable gases and gas mixtures as LPG with air (SNG - Synthetic Natural Gas). Economic analysis in many cases prove that to ensure interchangeability of gas would cost less than the increase in pipeline capacity to deliver the same quantity of natural gas. In addition, SNG systems and installations, could be considered as investments to improve security and flexibility of gas supply. Known existing methods for determining the interchangeability of gases in gas gear based on Wobbe index, which determines the heat input and the burning rate tide, which in turn is related to flame stability. Exceeding the Wobbe index of a value increases the amount of carbon monoxide in the exhaust than the permissible concentration. Methods of determining the interchangeability of gases is characterized by a gas in relation to the above-described phenomena by means of quantitative indicators, or using diagrams interchangeability, where the gas is characterized by the position of a point in a coordinate system. The best known method for determining the interchangeability of gases is Delbourg method, in which the gas is characterized by the revised (expanded) Wobbe Index (Wr), the combustion potential, rate of soot formation (Ich) and the ratio of the formation of yellow ends (Ij). Universal way to determine the interchangeability of gas is also Weaver accounting method. It does not require determination of the reference gas. It is designed for utensils for household gas and gas pressure p = 1.25 kPa. The criteria and definition of gas interchangeability volatility in practice to the combustion in a gas gear. In the case of gas exchange in industrial furnaces, interchangeability criteria are usually not very useful because of other conditions of combustion and heat exchange. In industrial reheating furnace gas is combusted in a sealed combustion chambers. Air supply is regulated. The exhaust gases are discharged into canals and the chimney to the atmosphere. The temperature difference between load (fuel gas) and the flame is much less than in the case of gas household appliances. In the furnace heat exchange takes place mainly by radiation in 85% to 95%. The value of heat flux flowing from the gas to a heated charge is not proportional to the heat load burners. Interchangeability of gas is linked by adding to natural gas, a certain amount of gas that is a substitute for natural gas in meeting the criteria for substitution in order to ensure certainty of supply of natural gas to customers. Gases that can be used in the processes of blending and used as replacement gases are mainly a mixture of propane and propane - butane (LPG - Liquid Petroleum Gas), landfill gas or biogas (LFG - Landfill Gas) and dimethyl ether (DME). One of the more well-known gas mixtures used in many countries around the world to compensate for peak demands is a mixture containing about 75% of natural gas and approximately 25% propane / air (LPG / air). Also in Poland is prepared to amend the provisions in this regard (at this moment - oxygen in the gas network can not exceed 0.2%). In this paper, the calculations of interchangeability of gas mixtures LFG - LPG and LPG - air (SNG) for natural gas was made. It was determined whether the analyzed mixtures have similar stable flame zones regardless of the quality of LFG fuel and whether they may in whole or in part replace CH4, without any modification of equipment suction air for combustion. The obtained results will determine whether the fuel can be used as a replacement for natural gas used in such household appliances and, possibly, industrial burners. In connection with the possibility of changes in the quality of LFG, depending on such factors as storage time, as pre-treatment, will be determined the degree of interchangeability of LFG as a fuel mixed with regard to its quality.

Development of a Natural Gas-Fired, Ultra-Low NOx Can Combustor for an 800 KW Gas Turbine

1991 ◽  
Author(s):  
K. O. Smith ◽  
A. C. Holsapple ◽  
H. K. Mak ◽  
L. Watkins
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Premixed Combustion ◽  
Experimental Results ◽  
Nox Emissions ◽  
Variable Geometry ◽  
Lean Premixed Combustion ◽  
Full Load ◽  
Primary Zone ◽  
Lean Premixed

The experimental results from the rig testing of an ultra-low NOx, natural gas-fired combustor for an 800 to 1000 kw gas turbine are presented. The combustor employed lean-premixed combustion to reduce NOx emissions and variable geometry to extend the range over which low emissions were obtained. Testing was conducted using natural gas and methanol. Testing at combustor pressures up to 6 atmospheres showed that ultra-low NOx emissions could be achieved from full load down to approximately 70% load through the combination of lean-premixed combustion and variable primary zone airflow.

scholarly journals Analysis of NOx Formation in a Hydrogen Fueled Gas Turbine Engine

2008 ◽  
Author(s):  
Peter Therkelsen ◽  
Tavis Werts ◽  
Vincent McDonell ◽  
Scott Samuelsen
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Full Range ◽  
Gas Turbine Engine ◽  
System Level ◽  
Stable Operation ◽  
No Production ◽  
No Emission ◽  
Nox Formation ◽  
Turbine Engine

A commercially available natural gas fueled gas turbine engine was operated on hydrogen. Three sets of fuel injectors were developed to facilitate stable operation while generating differing levels of fuel/air premixing. One set was designed to produce near uniform mixing while the others have differing degrees of non-uniformity. The emissions performance of the engine over its full range of loads is characterized for each of the injector sets. In addition, the performance is also assessed for the set with near uniform mixing as operated on natural gas. The results show that improved mixing and lower equivalence ratio decreases NO emission levels as expected. However, even with nearly perfect premixing, it is found that the engine, when operated on hydrogen, produces a higher amount of NO than when operated with natural gas. Much of this attributed to the higher equivalence ratios that the engine operates on when firing hydrogen. However, even at the lowest equivalence ratios run at low power conditions, higher NO was observed. Analysis of the potential NO formation effects of residence time, kinetic pathways of NO production via NNH, and the kinetics of the dilute combustion strategy used are evaluated. While no one mechanism appears to explain the reasons for the higher NO, it is concluded that each may be contributing to the higher NO emissions observed with hydrogen. In the present configuration with the commercial control system operating normally, it is evident that system level effects are also contributing to the observed NO emission differences between hydrogen and natural gas.

Sign in / Sign up

Export Citation Format

Share Document