Turn-Down Capability of Ansaldo Energia's GT26

2021 ◽  
Author(s):  
Ralf Jakoby ◽  
Jörg Rinn ◽  
Christoph Appel ◽  
Adrien Studerus
Keyword(s):  
Gas Turbines ◽  
Development Project ◽  
Combined Cycle ◽  
Operational Flexibility ◽  
Part Load ◽  
Fuel Flexibility ◽  
Single Feature ◽  
Low Load ◽  
Fast Start ◽  
Validation Tests

Abstract The operational flexibility of heavy-duty gas turbines is of increasing importance in today's power generation market. Fast start-up, fast loading, grid frequency support, fuel flexibility and turn-down capability are only some of the keywords that describe the challenges for GT manufacturers. This paper reports Ansaldo Energia's activities to further reduce the Minimum Environmental Load (MEL) of the GT26. The difficulties related to operation at very low loads and the solutions that were developed are explained. Furthermore, the results of engine validation tests of the new extended Low Load Operation (eLLO) and extended Low Part Load (eLPL) operation concepts are presented. The enhancement of the operational flexibility of the GT26 is in the focus of Ansaldo's development activities since many years. Its sequential combustion system is a very good basis for flexible and emission compliant operation down to very low loads. Ansaldo Energia's Low Part Load (LPL) and Low Load Operation (LLO) concepts are standard products in the GT26 flexibility portfolio and established in the market for many years. Ansaldo Energia has conducted a development project in the past two years in order to further reduce the minimum simple cycle and combined cycle loads. The extension of the LLO and LPL operating ranges and their combination into one single feature are the main targets of the project.

Turn-Down Capability of Ansaldo Energia’s GT26

2021 ◽  
Author(s):  
Ralf Jakoby ◽  
Jörg Rinn ◽  
Christoph Appel ◽  
Adrien Studerus
Keyword(s):  
Mass Flow ◽  
Gas Turbines ◽  
Development Project ◽  
Combined Cycle ◽  
Operational Flexibility ◽  
Part Load ◽  
Single Feature ◽  
Low Load ◽  
Fast Start ◽  
Base Load

Abstract The operational flexibility of heavy-duty gas turbines is of increasing importance in today’s power generation market. Fast start-up, fast loading, grid frequency support, fuel flexibility and turn-down capability are only some of the keywords that describe the challenges for GT manufacturers. This paper reports Ansaldo Energia’s activities to further reduce the Minimum Environmental Load (MEL) of the GT26. The difficulties related to operation at very low loads and the solutions that were developed are explained. Furthermore, the results of engine validation tests of the new extended Low Load Operation (eLLO) and extended Low Part Load (eLPL) operation concepts are presented. The enhancement of the operational flexibility of the GT26 is in the focus of Ansaldo’s development activities since many years. Its sequential combustion system is a very good basis for flexible and emission compliant operation down to very low loads. Ansaldo Energia’s Low Part Load (LPL) and Low Load Operation (LLO) concepts are standard products in the GT26 flexibility portfolio and established in the market for many years. Low Part Load (LPL) operation extends the standard operating range down to low loads by switching off individual burners in the second combustor (SEV combustor). The compressor mass flow can be varied between idle and base load levels. Low Load Operation is characterized by a combination of idle compressor mass flow and base load temperatures in the first Combustor (EV combustor). The SEV combustor is switched off. LLO is intended to be a “parking point”, where the plant can operate in combined cycle mode during times of low electricity demand. Ansaldo Energia has conducted a development project in the past two years in order to further reduce the minimum simple cycle and combined cycle loads. The extension of the LLO and LPL operating ranges and their combination into one single feature are the main targets of the project.

Part-Load Operation of Gas Turbines Induced by Co-Gasification of Coal and Biomass in an Integrated Gasification Combined Cycle Power Plant

2021 ◽  
Author(s):  
Silvia Ravelli
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Inlet Guide Vane ◽  
Inlet Temperature ◽  
Fuel Quality ◽  
Integrated Gasification Combined Cycle ◽  
Part Load ◽  
Wide Range ◽  
Integrated Gasification

Abstract This study takes inspiration from a previous work focused on the simulations of the Willem-Alexander Centrale (WAC) power plant located in Buggenum (the Netherlands), based on integrated gasification combined cycle (IGCC) technology, under both design and off-design conditions. These latter included co-gasification of coal and biomass, in proportions of 30:70, in three different fuel mixtures. Any drop in the energy content of the coal/biomass blend, with respect to 100% coal, translated into a reduction in gas turbine (GT) firing temperature and load, according to the guidelines of WAC testing. Since the model was found to be accurate in comparison with operational data, here attention is drawn to the GT behavior. Hence part load strategies, such as fuel-only turbine inlet temperature (TIT) control and inlet guide vane (IGV) control, were investigated with the aim of maximizing the net electric efficiency (ηel) of the whole plant. This was done for different GT models from leading manufactures on a comparable size, in the range between 190–200 MW. The influence of fuel quality on overall ηel was discussed for three binary blends, over a wide range of lower heating value (LHV), while ensuring a concentration of H2 in the syngas below the limit of 30 vol%. IGV control was found to deliver the highest IGCC ηel combined with the lowest CO2 emission intensity, when compared not only to TIT control but also to turbine exhaust temperature control, which matches the spec for the selected GT engine. Thermoflex® was used to compute mass and energy balances in a steady environment thus neglecting dynamic aspects.

Sequential Combustion in Ansaldo Energia Gas Turbines: The Technology Enabler for CO2-Free, Highly Efficient Power Production Based on Hydrogen

2020 ◽  
Author(s):  
Andrea Ciani ◽  
John P. Wood ◽  
Anders Wickström ◽  
Geir J. Rørtveit ◽  
Rosetta Steeneveldt ◽  
...  
Keyword(s):  
Power Generation ◽  
Free Energy ◽  
Gas Turbines ◽  
Carbon Capture ◽  
Power Plants ◽  
Carbon Capture And Storage ◽  
Combined Cycle ◽  
Fuel Flexibility ◽  
Combustion Technology ◽  
And Storage

Abstract Today gas turbines and combined cycle power plants play an important role in power generation and in the light of increasing energy demand, their role is expected to grow alongside renewables. In addition, the volatility of renewables in generating and dispatching power entails a new focus on electricity security. This reinforces the importance of gas turbines in guaranteeing grid reliability by compensating for the intermittency of renewables. In order to achieve the Paris Agreement’s goals, power generation must be decarbonized. This is where hydrogen produced from renewables or with CCS (Carbon Capture and Storage) comes into play, allowing totally CO2-free combustion. Hydrogen features the unique capability to store energy for medium to long storage cycles and hence could be used to alleviate seasonal variations of renewable power generation. The importance of hydrogen for future power generation is expected to increase due to several factors: the push for CO2-free energy production is calling for various options, all resulting in the necessity of a broader fuel flexibility, in particular accommodating hydrogen as a future fuel feeding gas turbines and combined cycle power plants. Hydrogen from methane reforming is pursued, with particular interest within energy scenarios linked with carbon capture and storage, while the increased share of renewables requires the storage of energy for which hydrogen is the best candidate. Compared to natural gas the main challenge of hydrogen combustion is its increased reactivity resulting in a decrease of engine performance for conventional premix combustion systems. The sequential combustion technology used within Ansaldo Energia’s GT36 and GT26 gas turbines provides for extra freedom in optimizing the operation concept. This sequential combustion technology enables low emission combustion at high temperatures with particularly high fuel flexibility thanks to the complementarity between its first stage, stabilized by flame propagation and its second (sequential) stage, stabilized by auto-ignition. With this concept, gas turbines are envisaged to be able to provide reliable, dispatchable, CO2-free electric power. In this paper, an overview of hydrogen production (grey, blue, and green hydrogen), transport and storage are presented targeting a CO2-free energy system based on gas turbines. A detailed description of the test infrastructure, handling of highly reactive fuels is given with specific aspects of the large amounts of hydrogen used for the full engine pressure tests. Based on the results discussed at last year’s Turbo Expo (Bothien et al. GT2019-90798), further high pressure test results are reported, demonstrating how sequential combustion with novel operational concepts is able to achieve the lowest emissions, highest fuel and operational flexibility, for very high combustor exit temperatures (H-class) with unprecedented hydrogen contents.

Expanding Fuel Flexibility in MHPS’ Dry Low NOx Combustor

2018 ◽  
Author(s):  
Katsuyoshi Tada ◽  
Kei Inoue ◽  
Tomo Kawakami ◽  
Keijiro Saitoh ◽  
Satoshi Tanimura
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Environmental Conservation ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Social Perspectives ◽  
Turbine Inlet ◽  
Fuel Flexibility

Gas-turbine combined-cycle (GTCC) power generation is clean and efficient, and its demand will increase in the future from economic and social perspectives. Raising turbine inlet temperature is an effective way to increase combined cycle efficiency and contributes to global environmental conservation by reducing CO2 emissions and preventing global warming. However, increasing turbine inlet temperature can lead to the increase of NOx emissions, depletion of the ozone layer and generation of photochemical smog. To deal with this issue, MHPS (MITSUBISHI HITACHI POWER SYSTEMS) and MHI (MITSUBISHI HEAVY INDUSTRIES) have developed Dry Low NOx (DLN) combustion techniques for high temperature gas turbines. In addition, fuel flexibility is one of the most important features for DLN combustors to meet the requirement of the gas turbine market. MHPS and MHI have demonstrated DLN combustor fuel flexibility with natural gas (NG) fuels that have a large Wobbe Index variation, a Hydrogen-NG mixture, and crude oils.

Gas Turbine Part Load Performance Testing: Comparison of Test Methodologies

2008 ◽  
Author(s):  
Thomas P. Schmitt ◽  
Herve Clement
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Guide Vane ◽  
Performance Testing ◽  
Load Level ◽  
Combined Cycle ◽  
Inlet Guide Vane ◽  
Performance Guarantee ◽  
Part Load ◽  
Advantages And Disadvantages

Current trends in usage patterns of gas turbines in combined cycle applications indicate a substantial proportion of part load operation. Commensurate with the change in operating profile, there has been an increase in the propensity for part load performance guarantees. When a project is structured such that gas turbines are procured as equipment-only from the manufacturer, there is occasionally a gas turbine part load performance guarantee that coincides with the net plant combined cycle part load performance guarantee. There are several methods by which to accomplish part load gas turbine performance testing. One of the more common methods is to operate the gas turbine at the specified load value and construct correction curves at constant load. Another common method is to operate the gas turbine at a specified load percentage and construct correction curves at constant percent load. A third method is to operate the gas turbine at a selected load level that corresponds to a predetermined compressor inlet guide vane (IGV) angle. The IGV angle for this third method is the IGV angle that is needed to achieve the guaranteed load at the guaranteed boundary conditions. The third method requires correction curves constructed at constant IGV, just like base load correction curves. Each method of test and correction embodies a particular set of advantages and disadvantages. The results of an exploration into the advantages and disadvantages of the various performance testing and correction methods for part load performance testing of gas turbines are presented. Particular attention is given to estimates of the relative uncertainty for each method.

CCPP Operational Flexibility Extension Below 30% Load Using Reheat Burner Switch-Off Concept

2015 ◽  
Author(s):  
Dirk Therkorn ◽  
Martin Gassner ◽  
Vincent Lonneux ◽  
Mengbin Zhang ◽  
Stefano Bernero
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Fast Response ◽  
Combined Cycle ◽  
Pollutant Emissions ◽  
Inlet Temperature ◽  
Operational Flexibility ◽  
Part Load ◽  
Combustion Technology ◽  
The Impact

Highly competitive and volatile energy markets are currently observed, as resulting from the increased use of intermittent renewable sources. Gas turbine combined cycle power plants (CCPP) owners therefore require reliable, flexible capacity with fast response time to the grid, while being compliant with environmental limitations. In response to these requirements, a new operation concept was developed to extend the operational flexibility by reducing the achievable Minimum Environmental Load (MEL), usually limited by increasing pollutant emissions. The developed concept exploits the unique feature of the GT24/26 sequential combustion architecture, where low part load operation is only limited by CO emissions produced by the reheat (SEV) burners. A significant reduction of CO below the legal limits in the Low Part Load (LPL) range is thereby achieved by individually switching the SEV burners with a new operation concept that allows to reduce load without needing to significantly reduce both local hot gas temperatures and CCPP efficiency. Comprehensive assessments of the impact on operation, emissions and lifetime were performed and accompanied by extensive testing with additional validation instrumentation. This has confirmed moderate temperature spreads in the downstream components, which is a benefit of sequential combustion technology due to the high inlet temperature into the SEV combustor. The following commercial implementation in the field has proven a reduction of MEL down to 26% plant load, corresponding to 18% gas turbine load. The extended operation range is emission compliant and provides frequency response capability at high plant efficiency. The experience accumulated over more than one year of successful commercial operation confirms the potential and reliability of the concept, which the customers are exploiting by regularly operating in the LPL range.

Part Load Operation of a Multiple-Injection Dry Low NOx Combustor on Hydrogen-Rich Syngas Fuel in an IGCC Pilot Plant

2015 ◽  
Author(s):  
Tomohiro Asai ◽  
Satoschi Dodo ◽  
Mitsuhiro Karishuku ◽  
Nobuo Yagi ◽  
Yasuhiro Akiyama ◽  
...  
Keyword(s):  
Power Systems ◽  
Pilot Plant ◽  
Gas Turbines ◽  
Combustion Efficiency ◽  
Combined Cycle ◽  
Multiple Injection ◽  
Load Range ◽  
Part Load ◽  
Combustion Of Hydrogen ◽  
Initial Staging

The successful development of coal-based integrated gasification combined cycle (IGCC) technology requires gas turbines capable of achieving the dry low-nitrogen oxides (NOx) combustion of hydrogen-rich syngas for low emissions and high plant efficiency. Mitsubishi Hitachi Power Systems, Ltd. (MHPS) has been developing a “multiple-injection combustor” to achieve the dry low-NOx combustion of hydrogen-rich syngas. This study suggests an advanced fuel staging comprising a hybrid partial combustion mode to improve the combustor’s part load performance. The purposes of this paper are to present the test results of the combustor with the advanced staging on a syngas fuel in an IGCC pilot plant, and to evaluate its performance. The syngas fuel produced in the plant contained approximately 50% carbon monoxide, 20% hydrogen, and 20% nitrogen by volume. In the test, the advanced staging reduced the maximum NOx at part load to 44 ppm (at 15% oxygen) compared with the initial staging with a maximum NOx of 75 ppm, and attained higher combustion efficiency above 98.7% over the part load range than the initial staging with combustion efficiency above 97.1%. In conclusion, the advanced staging improved the part load performance by achieving lower NOx emissions and higher combustion efficiency.

Flexible Combined Cycle Gas Turbine Power Plant Utilising Organic Rankine Cycle Technology

2016 ◽  
Author(s):  
Michael Welch ◽  
Nicola Rossetti
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Operational Flexibility

Historically gas turbine power plants have become more efficient and reduced the installed cost/MW by developing larger gas turbines and installing them in combined cycle configuration with a steam turbine. These large gas turbines have been designed to maintain high exhaust gas temperatures to maximise the power generation from the steam turbine and achieve the highest overall electrical efficiencies possible. However, in today’s electricity market, with more emphasis on decentralised power generation, especially in emerging nations, and increasing penetration of intermittent renewable power generation, this solution may not be flexible enough to meet operator demands. An alternative solution to using one or two large gas turbines in a large central combined cycle power plant is to design and install multiple smaller decentralised power plant, based on multiple gas turbines with individual outputs below 100MW, to provide the operational flexibility required and enable this smaller power plant to maintain a high efficiency and low emissions profile over a wide load range. This option helps maintain security of power supplies, as well as providing enhanced operational flexibility through the ability to turn turbines on and off as necessary to match the load demand. The smaller gas turbines though tend not to have been optimised for combined cycle operation, and their exhaust gas temperatures may not be sufficiently high, especially under part load conditions, to generate steam at the conditions needed to achieve a high overall electrical efficiency. ORC technology, thanks to the use of specific organic working fluids, permits efficient exploitation of low temperatures exhaust gas streams, as could be the case for smaller gas turbines, especially when working on poor quality fuels. This paper looks at how a decentralised power plant could be designed using Organic Rankine Cycle (ORC) in place of the conventional steam Rankine Cycle to maximise power generation efficiency and flexibility, while still offering a highly competitive installed cost. Combined cycle power generation utilising ORC technology offers a solution that also has environmental benefits in a water-constrained World. The paper also investigates the differences in plant performance for ORC designs utilising direct heating of the ORC working fluid compared to those using an intermediate thermal oil heating loop, and looks at the challenges involved in connecting multiple gas turbines to a single ORC turbo-generator to keep installed costs to a minimum.

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