Fuel Switchover at High Load, Integration Into an Engine Operation Concept

2014 ◽  
Author(s):  
Susanne Schell ◽  
Ghislain Singla
Keyword(s):  
Power Output ◽  
Gas Turbines ◽  
High Load ◽  
Combined Cycle ◽  
Fuel Oil ◽  
Load Range ◽  
Engine Operation ◽  
Fuel Gas ◽  
Standard Operation ◽  
Secondary Fuel

The capability to switch online from a main to a back-up fuel is a necessity for dual fuel gas turbines. The switching procedure is itself challenging; fuel gas, fuel oil and supporting systems need to be operated in parallel, with the safe start-up and shut-down of each system having to be ensured. Additionally, the requirements of gas turbine and combined cycle have to be considered; with the target to provide fast reliable fuel switching, without a major effect on the power output. Alstom’s GT26/GT24 High Load Fuel Switchover (HLFSW) fulfils these requirements. HLFSW is a concept which allows switching back and forth between fuel gas and fuel oil in the load range of base load down to 60 % relative GT load. A key feature of the HLFSW is the stable load during the complete duration of the fuel switchover process, ensuring nearly constant power output in combined cycle mode from the moment the fuel switchover is triggered until standard operation is achieved on the secondary fuel. In this paper the integration of the HLFSW into the engine operation concept is presented. It is shown, how the sequential combustion of the Alstom GT26/GT24 is transferred from primary to secondary fuel by sequential fuel switchover. The focus is on how the high load fuel switchover concept is embedded into the gas turbine’s engine operation concept, allowing a smooth transfer between the fuel gas standard operation concept and the fuel oil standard operation concept and vice-versa, resulting in a fuel switchover concept without any significant disturbances to the heat recovery steam generator (HRSG).

Recent Experimental Results on Gasification and Combustion of Low BTU Gas for Gas Turbines

1974 ◽  
Author(s):  
W. B. Crouch ◽  
W. G. Schlinger ◽  
R. D. Klapatch ◽  
G. E. Vitti
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Electrical Power ◽  
Combined Cycle ◽  
Experimental Results ◽  
Fuel Oil ◽  
Cooperative Research ◽  
Fuel Gas ◽  
Gasification Process ◽  
Cycle System

A proposed system is presented for low pollution power generation by means of a combined cycle gas turbine system using low Btu fuel gas produced from high sulfur residual oil and solid fuel. Experimental results and conclusions are presented from a cooperative research program involving Texaco Inc. and Turbo Power and Marine Systems, Inc. whereby high sulfur crude oil residue was partially oxidized with air to produce a 100 to 150 Btu/scf sulfur-free fuel gas for use in a turbine combustor. An FT4 gas turbine combustion chamber test demonstrated that low Btu gas can be efficiently burned with a large reduction in NOx emissions. Gas turbine modifications required to burn low Btu gas are described and projected NOx emission compared to No. 2 fuel oil and natural gas are shown for an FT4 gas turbine. Integration of the gas turbine combined cycle system to a low Btu gasification process is described. The system provides an efficient method of generating electrical power from high sulfur liquid fuels while minimizing emission of air and water pollutants.

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.

HRSG Duct Firing Revisited

2018 ◽  
Author(s):  
S. Can Gülen
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Fossil Fuel ◽  
Heat Rate ◽  
Combined Cycle ◽  
Efficiency Improvement ◽  
Combined Cycle Power Plant

Duct firing in the heat recovery steam generator (HRSG) of a gas turbine combined cycle power plant is a commonly used method to increase output on hot summer days when gas turbine airflow and power output lapse significantly. The aim is to generate maximum possible power output when it is most needed (and, thus, more profitable) at the expense of power plant heat rate. In this paper, using fundamental thermodynamic arguments and detailed heat and mass balance simulations, it will be shown that, under certain boundary conditions, duct firing in the HRSG can be a facilitator of efficiency improvement as well. When combined with highly-efficient aeroderivative gas turbines with high cycle pressure ratios and concomitantly low exhaust temperatures, duct firing can be utilized for small but efficient combined cycle power plant designs as well as more efficient hot-day power augmentation. This opens the door to efficient and agile fossil fuel-fired power generation opportunities to support variable renewable generation.

Optimization Concerns for Combined Cycle Power Plants: II — Optimum Fuel Gas Heating

2003 ◽  
Author(s):  
Walter I. Serbetci
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Heat Rate ◽  
Combined Cycle ◽  
Hot Water ◽  
Fuel Temperature ◽  
General Electric ◽  
Fuel Gas ◽  
Gas Heating ◽  
Overall Efficiency

As the second study in a sequence of studies conducted on the optimization of combined cycle plants [Ref. 1], this paper presents the effects of fuel gas heating on plant performance and plant economics for various 1×1×1 configurations. First, the theoretical background is presented to explain the effects of fuel gas heating on combustion turbine efficiency and on the overall efficiency of the combined cycle plant. Then, *CycleDeck-Performance Estimator™ and *GateCycle™ computer codes were used to investigate the impact of fuel gas heating on various 1×1×1 configurations. The configurations studied here are: 1) GE CC107FA with three pressure/reheat HRSG and General Electric PG7241(FA) gas turbine (Fig. 1), 2) GE CC106FA with three pressure/reheat HRSG and General Electric PG6101(FA) gas turbine and, 3) GE CC 107EA with three pressure/non-reheat HRSG with General Electric PG7121(EA) gas turbine. In all calculations, natural gas with high methane percentage is used as a typical fuel gas. Hot water from the outlet of IP economizer is used to heat the fuel gas from its supply temperature of 80 °F (27 °C). Heating the fuel gas to target temperatures of 150 °F, 200 °F, 250° F, 300 °F, 350 °F, 375 °F, 400 °F and 425 °F ( 66, 93, 121, 149, 177, 191, 204 and 218 °C), the combustion turbine power output, the combustion turbine heat rate and the plant power output and the corresponding heat rate are determined for each target fuel temperature. For each configuration, the heat transfer surface required to heat the fuel gas to the given target temperatures are also determined and budgetary price quotes are obtained for the fuel gas heaters. As expected, as the fuel temperature is increased, the overall efficiency (therefore the heat rate) improved, however at the expense of some small power output loss. Factoring in the fuel cost savings, the opportunity cost of the power lost, the cost of the various size performance heaters and the incremental auxiliary power consumption (if any), a cost-benefit analysis is carried out and the economically optimum fuel temperature and the corresponding performance heater size are determined for each 1×1×1 configuration.

scholarly journals Conceptual Mean-Line Design of Single and Twin-Shaft Oxy-Fuel Gas Turbine in a Semiclosed Oxy-Fuel Combustion Combined Cycle

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Majed Sammak ◽  
Egill Thorbergsson ◽  
Tomas Grönstedt ◽  
Magnus Genrup
Keyword(s):  
Mach Number ◽  
Gas Turbine ◽  
Mass Flow ◽  
Rotational Speed ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Fuel Gas ◽  
Power Turbine ◽  
Exit Mach Number ◽  
Line Design

The aim of this study was to compare single- and twin-shaft oxy-fuel gas turbines in a semiclosed oxy-fuel combustion combined cycle (SCOC–CC). This paper discussed the turbomachinery preliminary mean-line design of oxy-fuel compressor and turbine. The conceptual turbine design was performed using the axial through-flow code luax-t, developed at Lund University. A tool for conceptual design of axial compressors developed at Chalmers University was used for the design of the compressor. The modeled SCOC–CC gave a net electrical efficiency of 46% and a net power of 106 MW. The production of 95% pure oxygen and the compression of CO2 reduced the gross efficiency of the SCOC–CC by 10 and 2 percentage points, respectively. The designed oxy-fuel gas turbine had a power of 86 MW. The rotational speed of the single-shaft gas turbine was set to 5200 rpm. The designed turbine had four stages, while the compressor had 18 stages. The turbine exit Mach number was calculated to be 0.6 and the calculated value of AN2 was 40 · 106 rpm2m2. The total calculated cooling mass flow was 25% of the compressor mass flow, or 47 kg/s. The relative tip Mach number of the compressor at the first rotor stage was 1.15. The rotational speed of the twin-shaft gas generator was set to 7200 rpm, while that of the power turbine was set to 4800 rpm. A twin-shaft turbine was designed with five turbine stages to maintain the exit Mach number around 0.5. The twin-shaft turbine required a lower exit Mach number to maintain reasonable diffuser performance. The compressor turbine was designed with two stages while the power turbine had three stages. The study showed that a four-stage twin-shaft turbine produced a high exit Mach number. The calculated value of AN2 was 38 · 106 rpm2m2. The total calculated cooling mass flow was 23% of the compressor mass flow, or 44 kg/s. The compressor was designed with 14 stages. The preliminary design parameters of the turbine and compressor were within established industrial ranges. From the results of this study, it was concluded that both single- and twin-shaft oxy-fuel gas turbines have advantages. The choice of a twin-shaft gas turbine can be motivated by the smaller compressor size and the advantage of greater flexibility in operation, mainly in the off-design mode. However, the advantages of a twin-shaft design must be weighed against the inherent simplicity and low cost of the simple single-shaft design.

Operating Experience With the Latest Upgrade of Alstom’s Sequential Combustion GT26 Gas Turbine

2010 ◽  
Author(s):  
Matthias Hiddeman ◽  
Peter Marx
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Operating Experience ◽  
Business Case ◽  
Combined Cycle ◽  
Fuel Gas ◽  
Power Generators ◽  
Additional Degree ◽  
Performance Improvements ◽  
Main Driver

The GT26 gas turbine provides an additional degree of flexibility as the engine operates at high efficiencies from part load to full load while still maintaining low NOx emissions. The sequential combustion, with the EV burner as the basis for this flexibility also extends to the ability to handle wide fluctuations in fuel gas compositions. Increased mass flow was the main driver for the latest GT26 upgrade, resulting in substantial performance improvements. In order to ensure high levels of reliability and availability Alstom followed their philosophy of evolutionary steps to continuously develop their gas turbines. A total of 47 engines of this upgrade of the GT26 gas turbine have been ordered worldwide to date (Status: January 2010) enhancing the business case of power generators by delivering superior operational and fuel flexibility and combined cycle efficiencies up to and beyond 59%.

Daesan Combined Cycle Power Plant: Successful Operating Experience on Low Sulphur Waxy Residual Fuel Oil

2001 ◽  
Author(s):  
Koen-Woo Lee ◽  
Hwan-Doo Kim ◽  
Sung-Il Wi ◽  
Jean-Pierre Stalder
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Capital Expenditure ◽  
Operating Experience ◽  
Combined Cycle ◽  
Fuel Oil ◽  
Heat Recovery Boiler ◽  
Particulate Emissions ◽  
Combined Cycle Power Plant ◽  
Residual Fuel Oil

This paper presents and discusses the successful operating experience and the issues related to burning low sulphur waxy residual (LSWR) fuel oil at the 507 MW IPP Daesan Combined Cycle Power Plant. The power plant was built and is operated by Hyundai Heavy Industries (HHI). It comprises four Siemens-Westinghouse 501D5 engines, each with a heat recovery boiler including supplementary firing and one steam turbine. This plant, commissioned in 1997, is designed to burn LSWR fuel oil. LSWR fuel oil was selected because of the lower fuel cost as compared to LNG and other liquid fuels available in Korea. By adding a combustion improver to the LSWR fuel oil it is possible for HHI to comply with the tight Korean environmental regulations, despite the tendency for heavy smoke and particulate emissions when burning this type of fuel oil. The successful operating experience, availability, reliability and performance achieved in Daesan, as well as the commercial viability (which by far offsets the additional capital expenditure and the additional related O&M costs) demonstrate that LSWR fuel oil firing in heavy duty gas turbines is rewarding. This is especially important in view of the growing disposal problems of residuals at refineries around the world.

Development of a Three-Staged Low Emissions Combustor for Industrial Small-Size Gas Turbines

1999 ◽  
Author(s):  
Hiroshi Sato ◽  
Toshiji Amano ◽  
Yoshihiro Iiyama ◽  
Masaaki Mori ◽  
Tsuneaki Nakamura
Keyword(s):  
Gas Turbines ◽  
Gas Flow ◽  
Superior Performance ◽  
Staged Combustion ◽  
Engine Operation ◽  
Fuel Gas ◽  
Low Emission ◽  
Lean Premixed ◽  
Development Temperature ◽  
Combustor Liner

This paper describes the development of an ultra-low emission single-can combustor applicable to 200 kW to 3 MW size natural gas-driven gas turbines for cogeneration systems. The combustor, called a three-staged combustor, was designed by applying the theory of lean premixed staged combustion. The combustor comprises two sets of premixing injector tubes located around the combustor liner downstream of the premixing nozzle equipped with a pilot diffusion nozzle in the center. The combustor controls engine output solely by varying the fuel gas flow without the need for complex variable geometry, such as inlet guide vanes, for combustion airflow control. Reliability, response to load variation and retrofit capability have been greatly improved along with wide low-emission operating range. As the result of the atmospheric rig tests, the three-staged combustor has demonstrated superior performance of 3.5 ppm NOx (O2 = 15%) and 7 ppm CO (O2 = 15%) at full load. Assuming the relationship between NOx emission and pressure and taking into account sequential CO oxidation occurring in the scroll, the performance of the combustor at engine operation is expected to be less than 9 ppm NOx (O2 = 15%) and 50 ppm CO (O2 = 15%) emissions between 25% and 100% engine load. During the development, temperature distribution in the atmospheric combustion was measured in detail to gain comprehensive understanding of the low emissions combustion phenomena. The results of the measurement were compared with the theory of lean premixed staged combustion. Employing the concept of effective mixing ratio, the theory of lean premixed staged combustion has proved to be a powerful method to design a lean premixed staged combustor.

Planning for Extensive Validation of the Siemens H-Class Gas Turbine SGT5-8000H at the Power Plant Irsching

2009 ◽  
Author(s):  
S. Abens ◽  
F. Eulitz ◽  
I. Harzdorf ◽  
M. Jaenchen ◽  
W. Fischer ◽  
...  
Keyword(s):  
Power Plant ◽  
Data Acquisition ◽  
Gas Turbine ◽  
Gas Turbines ◽  
World Wide ◽  
Product Line ◽  
Combined Cycle ◽  
Engine Operation ◽  
Test Execution ◽  
Evolutionary Innovation

In response to the increasing world-wide need for reliable, lowest-cost and environmentally compatible generation of energy, Siemens Energy has developed a new generation of H-class gas turbines with a power of 530+ MW and an efficiency of more than 60% in combined-cycle. The SGT5-8000H has been developed based on an evolutionary innovation concept which can be characterized by a technology platform strategy and prior component pre-validation. To ensure that the new product line can be brought to market with extensive testing and operation experience under real power plant conditions, a comprehensive validation program was launched in December 2007 at the prototypical power plant in Irsching. The 18 month validation program consists of multiple measurement campaigns, covering the full operation range starting from the hot commissioning to a final endurance test in single-cycle configuration. To gain the required data for the validation, the SGT5-8000H prototype has been equipped with close to 3000 measuring sensors and an extensive data acquisition system. For the realization of the largest gas turbine validation program ever conducted by Siemens, innovation in various aspects of test execution and evaluation had to be realized. Dedicated teams are operating and monitoring the engine operation from on-site and from the world-wide engineering locations utilizing real-time data acquisition, monitoring and evaluation methods. This paper describes the infrastructure and settings of the validation program in terms of the testing scope, facilities, methods and tools.

A Fuel Gas System Transient Study for Combined Cycle Plants

2014 ◽  
Author(s):  
Yizhou Yan
Keyword(s):  
Gas Turbines ◽  
Power Plants ◽  
Gas Flow ◽  
Pressure Control ◽  
Combined Cycle ◽  
Transient Model ◽  
Fuel Gas ◽  
Gas System ◽  
Set Up ◽  
Loop Tuning

Fuel gas for many Combined Cycle Power Plants is supplied directly by the gas provider’s regulator station in locations where the gas pipeline pressure is sufficient without further compression. Other locations require one or more onsite compressors to boost the fuel gas pressure. A rising concern is the fuel gas system transient response immediately after a significant reduction in the plant fuel gas consumption. Transient analysis models have been developed for typical fuel gas systems of combined cycle plants to ensure that the system is configured to respond appropriately to unplanned disturbances in fuel gas flow such as when a gas turbine trip occurs. Pressure control (regulator) and booster compressor control loop tuning parameters based on quantitative transient model results could be applied to set up targets for use in specifying and commissioning the fuel gas system. Case studies are presented for typical large combined cycle plants with two gas turbines taking fuel from a common plant header. This is done for designs without or with fuel gas booster compressors.

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