Pentane Rich Fuels for Standard Siemens DLE Gas Turbines

2011 ◽  
Author(s):  
Mats Andersson ◽  
Anders Larsson ◽  
Arturo Manrique Carrera
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Dynamics ◽  
Heating Value ◽  
Special Adaptation ◽  
Fuel Flexibility ◽  
Combustion Properties ◽  
Model Substance ◽  
Wobbe Index

Associated gases at oil wells are often rich in heavy hydrocarbons (HHC, here denoting hydrocarbons heavier than propane). HHC cause handling difficulties and the combustion properties are quite different from standard natural gas. For this and other reasons HHC rich associated gases are often flared or vented. This is an enormous waste of useable energy and a significant contribution to emissions of pollutants, global CO2 and other greenhouse gases. Siemens Industrial Turbomachinery AB in Finspong (SIT AB) recently tested a standard DLE 25 MW SGT-600 gas turbine and a standard 31 MW SGT-700 gas turbine with HHC rich natural gas. Pentane was chosen as a model substance for HHC. The tested gases had up to 30% of the fuel heating value from pentane. The unmodified standard DLE gas turbines proved to be very tolerant to the tested pentane rich gases. CO emissions were reduced with increasing pentane content in the fuel for the same power output. NOx was observed to increase linearly with the pentane content. Combustion dynamics was affected mildly, but noticeably by the pentane rich fuel. This result, together with earlier presented results for the same DLE engines on nitrogen rich natural gases, gives an accepted and tested total LHV range of 25–50 MJ/kg and Wobbe index range of 25–55 MJ/Nm3. No special adaptation of the gas turbines was necessary for allowing this wide fuel range. The benefit of increased and proven fuel flexibility is obvious as it allows the gas turbine owner to make full use of opportunity fuels and to supply power at low fuel cost.

Extension of Fuel Flexibility by Combining Intelligent Control Methods for Siemens SGT-400 Dry Low Emission Combustion System

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Kexin Liu ◽  
Phill Hubbard ◽  
Suresh Sadasivuni ◽  
Ghenadie Bulat
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Combustion System ◽  
Combustion Dynamics ◽  
Heating Value ◽  
Fuel Flexibility ◽  
Wide Range ◽  
Wobbe Index ◽  
Industrial Gas Turbine ◽  
The Impact

Extension of gas fuel flexibility of a current production SGT-400 industrial gas turbine combustor system is reported in this paper. A SGT-400 engine with hybrid combustion system configuration to meet a customer's specific requirements was string tested. This engine was tested with the gas turbine package driver unit and the gas compressor-driven unit to operate on and switch between three different fuels with temperature-corrected Wobbe index (TCWI) varying between 45 MJ/m3, 38 MJ/m3, and 30 MJ/m3. The alteration of fuel heating value was achieved by injection or withdrawal of N2 into or from the fuel system. The results show that the engine can maintain stable operation on and switching between these three different fuels with fast changeover rate of the heating value greater than 10% per minute without shutdown or change in load condition. High-pressure rig tests were carried out to demonstrate the capabilities of the combustion system at engine operating conditions across a wide range of ambient conditions. Variations of the fuel heating value, with Wobbe index (WI) of 30 MJ/Sm3, 33 MJ/Sm3, 35 MJ/Sm3, and 45 MJ/Sm3 (natural gas, NG) at standard conditions, were achieved by blending NG with CO2 as diluent. Emissions, combustion dynamics, fuel pressure, and flashback monitoring via measurement of burner metal temperatures, were the main parameters used to evaluate the impact of fuel flexibility on combustor performance. Test results show that NOx emissions decrease as the fuel heating value is reduced. Also note that a decreasing fuel heating value leads to a requirement to increase the fuel supply pressure. Effect of fuel heating value on combustion was investigated, and the reduction in adiabatic flame temperature and laminar flame speed was observed for lower heating value fuels. The successful development program has increased the capability of the SGT-400 standard production dry low emissions (DLE) burner configuration to operate with a range of fuels covering a WI corrected to the normal conditions from 30 MJ/N·m3 to 49 MJ/N·m3. The tests results obtained on the Siemens SGT-400 combustion system provide significant experience for industrial gas turbine burner design for fuel flexibility.

Extension of Fuel Flexibility in the Siemens Dry Low Emissions SGT-300-1S to Cover a Wobbe Index Range of 15 to 49 MJ/m3

2012 ◽  
Author(s):  
Kexin Liu ◽  
Varkey Alexander ◽  
Victoria Sanderson ◽  
Ghenadie Bulat
Keyword(s):  
Natural Gas ◽  
Nox Reduction ◽  
Operating Conditions ◽  
Combustion System ◽  
Combustion Dynamics ◽  
Fuel Supply ◽  
Supply Pressure ◽  
Fuel Flexibility ◽  
Wobbe Index ◽  
Standard Production

The extension of gas fuel flexibility in the Siemens SGT-300 single shaft (SGT-300-1S) is reported in this paper. A successful development programme has increased the capability of the Siemens Industrial Turbomachinery, Lincoln (SITL) dry low emissions (DLE) burner configuration to a fuel range covering a Wobbe Index (WI) from 15 to 49 MJ/m3. The standard SGT-300-1S SITL DLE combustion hardware allowed for gas and liquid fuels within a specified range typically associated with natural gas and diesel, respectively. Field operation of the standard production SGT-300-1S has confirmed the reliable operation with an extension to the fuels range to include processed land fill gas (PLG) from 32 to 49 MJ/m3. The further extension of the fuel range for the SGT-300-1S SITL DLE combustion system was achieved through high pressure testing of a single combustion system at engine operating conditions. The rig facility allowed for the actual fuel type to be tested using a mixing plant. The variations in fuel heating value were achieved by blending natural gas with diluent CO2 and/or N2. Various diagnostics were used to assess the performance of the combustion system including measurement of combustion dynamics, temperature, fuel supply pressure and emissions of NOx, CO and unburned hydrocarbon (UHC). The results of the testing showed that the standard production burner can operate for a fuel with WI as low as 23 MJ/m3 which corresponds to 35% CO2 (in volume) in the fuel. This range can be extended to 15 MJ/m3 (54.5% CO2 in the fuel) with only minor modification, to control losses through the burner and to maintain similar fuel injection characteristics. The SITL DLE combustion system is able to cover a WI range of 15 to 49 MJ/m3 in two configurations. The results of testing showed a lowering in WI, from diluting with CO2 and/or N2, a benefit in NOx reduction is observed. This decrease in WI may lead to an increased requirement in fuel supply pressure.

Gas Turbine Gas Fuel Composition Performance Correction Using Wobbe Index

2010 ◽  
Author(s):  
Bryan Li ◽  
Mike J. Gross ◽  
Thomas P. Schmitt
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Performance Test ◽  
Test Accuracy ◽  
Fuel Composition ◽  
Gas Composition ◽  
Fuel Gas ◽  
Heating Value ◽  
Performance Effects ◽  
Wobbe Index

Gas turbine thermal performance is dependent on many external conditions, including fuel gas composition. Variations in composition cause changes in output and heat consumption during operation. Measured performance must be corrected to specified reference conditions prior to comparison against performance specifications. The fuel composition is one such condition for which performance corrections are required. The methodology of fuel composition corrections can take various forms. One current method of correction commonly used is to characterize fuel composition effects as a function of heating value and hydrogen-to-carbon ratio. This method has been used in the past within a limited range of fuel composition variation around the expected composition, yielding relatively small correction factors on the order of +/− 0.1%. Industry trends suggest that gas turbines will continue to be exposed to broader ranges of gas constituents, and the corresponding performance effects will be much larger. For example, liquefied natural gas, synthesized low BTU fuel, and bio fuels are becoming more common, with associated performance effects of +/− 0.5% or greater. As a result of these trends, performance test results will bear a greater dependency on fuel composition corrections. Hence, a more comprehensive correction methodology is required to encompass a broader range of fuel constituents encountered. Combustion system behavior, specifically emissions and flame stability, is also influenced by variations in fuel gas composition. The power generation industry uses Wobbe Index as an indicator of fuel composition. Wobbe Index relates the heating value of the fuel to its density. High variations in Wobbe Index can cause operability issues including combustion dynamics and increased emissions. A new method for performance corrections using Wobbe Index as the correlating fuel parameter has been considered. Analytical studies have been completed with the aid of thermodynamic models to identify the extent to which the Wobbe Index can be used to correlate the response of the gas turbine performance parameters to fuel gas composition. Results of the study presented in this paper suggest that improved performance test accuracy can be achieved by using Wobbe Index as a performance correction parameter, instead of the aforementioned conventional fuel characteristics. Furthermore, a relationship between this method’s accuracy and CO2 content of fuel is established such that an additional correction yields results with even better accuracy. This proposed method remains compliant with intent of internationally accepted test codes such as ASME PTC-22, ASME PTC-46, and ISO 2314.

Enhanced Fuel Flexibility and Emissions Compliance for Gas Turbines Through Model Based Controls Technology

2013 ◽  
Author(s):  
Ranjith Malapaty ◽  
Suresh M. V. J. J.
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbines ◽  
Power Plants ◽  
Power Demand ◽  
Combustion Dynamics ◽  
Fuel Flexibility ◽  
Plant Operations ◽  
Lng Fuel ◽  
Alternate Fuels

The world is facing complex and mounting environmental challenges. Increased fuel costs and increased market capacity in power generation markets is driving a transformation in power plant operations. Power plants are seeking ways to maximize revenue potential during peak conditions and minimize operational costs during off-peak conditions. Although proven natural gas reserves have increased globally by nearly 50% over the last 20 years, much of this growth has been focused in select regions and countries. In parallel to the discovery of new reserves is the increase in power demand across the globe. However, there are many regions of the globe in which power demand is not being matched by increased local supplies of natural gas, or in infrastructure required to supply natural gas to power generation assets. Given these drivers, there is growing global interest in LNG & alternate fuels. This phenomenon is driving a trend to explore the potential of using LNG fuels which can be easily transported across the globe as an alternative for power generation. In a carbon-constrained environment, the technology trend is for combustion systems capable of burning LNG fuel in combination with delivering the required operability. This paper will focus on developments in GE’s heavy duty gas turbines that enable operation on fuels with varying properties, providing fuel flexibility for sustainable power generation and better emissions compliance. GE’s turbine control system employs physics-based models of gas turbine operability boundaries (e.g., emissions, combustion dynamics, etc.), to continuously estimate current boundary levels and make adjustments as required.

Effect of Change in Fuel Compositions and Heating Value on Ignition and Performance for Siemens SGT-400 Dry Low Emission Combustion System

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
Kexin Liu ◽  
Pete Martin ◽  
Victoria Sanderson ◽  
Phill Hubbard
Keyword(s):  
Natural Gas ◽  
Fuel Composition ◽  
Test Results ◽  
Combustion System ◽  
Combustion Dynamics ◽  
Heating Value ◽  
Fuel Flexibility ◽  
Low Emission ◽  
Burner Design ◽  
Industrial Gas Turbine

The influence of changes in fuel composition and heating value on the performance of an industrial gas turbine combustor was investigated. The combustor tested was a single cannular combustor for Siemens SGT-400 13.4 MW dry low emission engine. Ignition, engine starting, emissions, combustion dynamics, and flash back through burner metal temperature monitoring were among the parameters investigated to evaluate the impact of fuel flexibility on combustor performance. Lean ignition and extinction limits were measured for three fuels with different heat values in term of Wobbe Index (WI): 25, 28.9, and 45 MJ/Sm3 (natural gas). The test results show that the air fuel ratio at lean ignition/extinction limits decreases and the margin between the two limits tends to be smaller as fuel heat value decreases. Engine start tests were also performed with a lower heating value fuel and results were found to be comparable to those for engine starting with natural gas. The combustor was further tested in a high pressure air facility at real engine operating conditions with different fuels covering WIs from 17.5 to 70 MJ/Sm3. The variation in fuel composition and heating value was achieved in a gas mixing plant by blending natural gas with CO2, CO, N2, and H2 (for the fuel with WI lower than natural gas) and C3H8 (for the fuel with WI higher than natural gas). Test results show that a benefit in NOx reduction can be seen for the lower WI fuels without H2 presence in the fuel and there are no adverse impacts on combustor performance except for the requirement of higher fuel supply pressure, however, this can be easily resolved by minor modification through the fuel injection design. Test results for the H2 enriched and higher WI fuels show that NOx, combustion dynamics and flash back have been adversely affected and major change in burner design is required. For the H2 enriched fuel, the effect of CO and H2 on combustor performance was also investigated for the fuels having a fixed WI of 29 MJ/Sm3. It is found that H2 dominates the adverse impact on combustor performance. The chemical kinetic study shows that H2 has significant effect on flame speed change and CO has significant effect on flame temperature change. Although the tests were performed on the Siemens SGT-400 combustion system, the results provide general guidance for the challenge of industrial gas turbine burner design for fuel flexibility.

Effect of Change in Fuel Compositions and Heating Value on Ignition and Performance for Siemens SGT-400 Dry Low Emission Combustion System

2013 ◽  
Author(s):  
Kexin Liu ◽  
Pete Martin ◽  
Victoria Sanderson ◽  
Phill Hubbard
Keyword(s):  
Natural Gas ◽  
Fuel Composition ◽  
Test Results ◽  
Combustion System ◽  
Combustion Dynamics ◽  
Heating Value ◽  
Fuel Flexibility ◽  
Low Emission ◽  
Burner Design ◽  
Industrial Gas Turbine

The influence of changes in fuel composition and heating value on the performance of an industrial gas turbine combustor was investigated. The combustor tested was a single cannular combustor for Siemens SGT-400 13.4 MW dry low emission (DLE) engine. Ignition, engine starting, emissions, combustion dynamics and flash back through burner metal temperature monitoring were among the parameters investigated to evaluate the impact of fuel flexibility on combustor performance. Lean ignition and extinction limits were measured for three fuels with different heat values in term of Wobbe Index (WI): 25, 28.9 and 45 MJ/Sm3 (natural gas). The test results show that the air fuel ratio (AFR) at lean ignition/extinction limits decreases and the margin between the two limits tends to be smaller as fuel heat value decreases. Engine start tests were also performed with a lower heating value fuel and results were found to be comparable to those for engine starting with natural gas. The combustor was further tested in a high pressure air facility at real engine operating conditions with different fuels covering WIs from 17.5 to 70 MJ/Sm3. The variation in fuel composition and heating value was achieved in a gas mixing plant by blending natural gas with CO2, CO, N2 and H2 (for the fuel with WI lower than natural gas) and C3H8 (for the fuel with WI higher than natural gas). Test results show that a benefit in NOx reduction can be seen for the lower WI fuels without H2 presence in the fuel and there are no adverse impacts on combustor performance except for the requirement of higher fuel supply pressure, however, this can be easily resolved by minor modification through the fuel injection design. Test results for the H2 enriched and higher WI fuels show that NOx, combustion dynamics and flash back have been adversely affected and major change in burner design is required. For the H2 enriched fuel, the effect of CO and H2 on combustor performance was also investigated for the fuels having a fixed WI of 29 MJ/Sm3. It is found that H2 dominates the adverse impact on combustor performance. The chemical kinetic study shows that H2 has significant effect on flame speed change and CO has significant effect on flame temperature change. Although the tests were performed on the Siemens SGT-400 combustion system, the results provide general guidance for the challenge of industrial gas turbine burner design for fuel flexibility.

FlameSheet™ Combustor Engine and Rig Validation for Operational and Fuel Flexibility With Low Emissions

2016 ◽  
Author(s):  
Peter Stuttaford ◽  
Hany Rizkalla ◽  
Khalid Oumejjoud ◽  
Nicolas Demougeot ◽  
Justin Bosnoian ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Heavy Duty ◽  
Load Range ◽  
Fuel Gas ◽  
Combustion Dynamics ◽  
Operational Profile ◽  
Fuel Flexibility ◽  
The Future

Flexibility is key to the future success of natural gas fired power generation. As renewable energy becomes more widely used, the need for reliable, flexible generation will increase. As such, gas turbines capable of operating efficiently and in emissions compliance from extended low load to full load will have a significant advantage. A wider range of gas fuels, including shale gas and refinery/industrial byproduct gas, is becoming increasingly available, with the opportunity to further reduce the cost of electricity. A combustion system capable of operating with wider ranges of heavy hydrocarbons, hydrogen and inerts will have an advantage to accommodate the future fuel gas trends and provide value to gas turbine operators. The FlameSheet™ combustor incorporates a novel dual zone burn system to address operational and fuel flexibility. It provides low emissions, extended turndown and fuel flexibility. FlameSheetTM is simply retrofittable into existing installed E/F-class heavy duty gas turbines and is designed to meet the energy market drivers set forth above. The operating principle of the new combustor is described, and details of a full scale high pressure rig test and engine validation program are discussed, providing insight on rig and engine emissions, as well as combustion dynamics performance. The FlameSheetTM implementation and validation results on a General Electric 7FA heavy duty gas turbine operating in a combined cycle power plant is discussed with emphasis on operational profile optimization to accommodate the heat recovery steam generator (HRSG), while substantially increasing the gas turbine normal operating load range.

Alternate Fuels Capability of Gas Turbines in the Process Industry

1976 ◽  
Author(s):  
W. J. Hefner
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
Process Industry ◽  
Liquid Fuels ◽  
Status Report ◽  
Gasification Process ◽  
Fuel Flexibility ◽  
Combustion Properties ◽  
Performance And Emissions ◽  
Alternate Fuels

As we move into the latter 1970’s and early 1980’s, we can anticipate a period of continuing uncertainty in availability of fuel supplies for the process industry. Even though the overall picture is unclear, there are some aspects of the total problem that are predictable, with a reasonable degree of confidence. One of the developments that can be predicted on the domestic scene is the unavailability of natural gas as an industrial fuel. Short supplies of this resource have significantly limited the installation of new facilities utilizing natural gas as a fuel supply, as well as creating a need to convert existing equipment to use alternate supplies of fuel where uninterruptable sources of natural gas are no longer available. This paper discusses the fuel flexibility of heavy-duty gas turbines and is a status report on the capability of today’s equipment. In addition, techniques for evaluating alternate gas turbine fuels including requirements for cleanliness, combustion properties, physical properties, composition, performance and emissions characteristics, etc., are discussed. Fuels which are covered include: Gasification Process Derived Fuels, By-Product Gases, Distillate Oil, Crude Oil, Residual Oil, Vaporized Liquid Fuels, and Liquefied Coal Products.

Retrofittable Solutions to Keep Existing Gas Turbine Power Plants Viable and Profitable in an Increasingly Dynamic Power Generation Market: Validation of Low Pressure Drop FlameSheet™ Combustor

2019 ◽  
Author(s):  
Fred Hernandez ◽  
Hany Rizkalla
Keyword(s):  
Power Plant ◽  
Pressure Drop ◽  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Load Range ◽  
Pressure Losses ◽  
Fuel Flexibility

Abstract As renewable energy sources continue their global energy market penetration, new natural gas fired power plant installations have decreased significantly. The reduction in new installed capacity has increased pressure on operators to profitably maintain and expand their existing fleet capability. Retrofitting existing gas turbines to increase baseload power output, expand fuel flexibility and provide a wider operating load range are key natural gas fired power plant market demands. The FlameSheet™ combustor system addresses these considerations with a novel “dual-zone burn system” design that reduces emissions, increases fuel flexibility and reduces pressure losses to improve thermal cycle efficiency. The present work presents the results of FlameSheet™ installations into GE 7F.03 heavy duty gas turbines at two commercial sites. The first installation combined FlameSheet™ with PSM’s Gas Turbine Optimization Package (GTOP) to provide higher output through a combination of lower combustor pressure drop, higher mass flows and an increase in firing temperature, while maintaining sub-9ppm NOx emissions across the expanded operating range. Results are also presented for a second site on a unit that operates with up to 5% hydrogen blend into the baseline natural gas, where a reduction in NOx to sub-4 ppm levels at a typical 7F.03 baseload point has been safely and reliably achieved. Both results continue to demonstrate that fuel flexibility and expanded operational windows are possible to “future proof” existing gas turbine installations at a fraction of the cost of a new unit installation.

Experimental and Reactor Network Study of Nitrogen Dilution Effects on NOX Formation for Natural Gas and Syngas at Elevated Pressures

2013 ◽  
Author(s):  
Ivan R. Sigfrid ◽  
Ronald Whiddon ◽  
Robert Collin ◽  
Jens Klingmann
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Central Body ◽  
Negative Impact ◽  
Flame Temperature ◽  
Fourth Generation ◽  
Atmospheric Conditions ◽  
Experimental Conditions ◽  
Wobbe Index

Gas turbines emissions, NOX in particular, have negative impact on the environment. To limit the emissions gas turbine burners are constantly improved. In this work, a fourth generation SIT (Siemens Industrial Turbomachinery) burner is studied to gain information about the formation of NOX emissions. The gas mixtures for the full burner are limited to natural gas with different nitrogen dilutions. The dilutions vary from undiluted to Wobbe index 40 and 30 MJ/m3. In addition to the full burner, the central body (the RPL – Rich/Pilot/Lean) is investigated. Methane is used to characterize standard gas turbine operation, and a non-standard fuel is explored using a generic syngas (67.5 % Hydrogen, 22.5 % Carbon monoxide and 10 % Methane). Both these gases are also investigated after dilution with nitrogen to a Wobbe index of 15 MJ/m3. The experiments are performed in a high-pressure facility. The pressures for the central body burner are 3, 6 and 9 bar. For the full burner the pressures are 3, 4.5 and 6 bar. The combustion air is preheated to 650 K. The emission measurements are sampled with an emission probe at the end of the combustor liner, and analyzed in an emission rack. The results are compared with previous investigations made at atmospheric conditions. The burner is modeled using a PSR and plug flow network to show which reaction paths are important in the formation of emissions for the burner under the experimental conditions. The measurement results show that the NOX concentration increases with pressure and flame temperature. With increasing dilution the NOX concentration is decreased. For rich mixtures PSR calculations show that the NOX concentration decreases with pressure.

Sign in / Sign up

Export Citation Format

Share Document