Ancillary Services Potential for Flexible Combined Cycles

2021 ◽  
Author(s):  
Alberto Vannoni ◽  
Jose Angel Garcia ◽  
Weimar Mantilla ◽  
Rafael Guedez ◽  
Alessandro Sorce
Keyword(s):  
Electricity Market ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Ancillary Services ◽  
Ancillary Service ◽  
Spinning Reserve ◽  
Service Market ◽  
Partial Load ◽  
Ancillary Services Market

Abstract Combined Cycle Gas Turbines, CCGTs, are often considered as the bridging technology to a decarbonized energy system thanks to their high exploitation rate of the fuel energetic potential. At present time in most European countries, however, revenues from the electricity market on their own are insufficient to operate existing CCGTs profitably, also discouraging new investments and compromising the future of the technology. In addition to their high efficiency, CCGTs offer ancillary services in support of the operation of the grid such as spinning reserve and frequency control, thus any potential risk of plant decommissioning or reduced investments could translate into a risk for the well-functioning of the network. To ensure the reliability of the electricity system in a transition towards a higher share of renewables, the economic sustainability of CCGTs must be preserved, for which it becomes relevant to monetize properly the ancillary services provided. In this paper, an accurate statistical analysis was performed on the day-ahead, intra-day, ancillary service, and balancing markets for the whole Italian power-oriented CCGT fleet. The profitability of 45 real production units, spread among 6 market zones, was assessed on an hourly basis considering local temperature, specific plant layouts, and off-design performance. The assessment revealed that net income from the ancillary service market doubled, on average, the one from the day-ahead energy market. It was observed that to be competitive in the ancillary services market CCGTs are required to be more flexible in terms of ramp rates, minimum environmental loads, and partial load efficiencies. This paper explores how integrating a Heat Pump and a Thermal Energy Storage within a CCGT could allow improving its competitiveness in the ancillary services market, and thus its profitability, by means of implementing a model of optimal dispatch operating on the ancillary services market.

Three Spool High Efficiency Small Scale Gas Turbine Concept

2017 ◽  
Author(s):  
Matti Malkamäki ◽  
Ahti Jaatinen-Värri ◽  
Antti Uusitalo ◽  
Aki Grönman ◽  
Juha Honkatukia ◽  
...  
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
Small Scale ◽  
Inlet Temperature ◽  
Substantial Impact ◽  
Electrical Efficiency ◽  
Partial Load ◽  
Reciprocating Engines

Decentralized electricity and heat production is a rising trend in small-scale industry. There is a tendency towards more distributed power generation. The decentralized power generation is also pushed forward by the policymakers. Reciprocating engines and gas turbines have an essential role in the global decentralized energy markets and improvements in their electrical efficiency have a substantial impact from the environmental and economic viewpoints. This paper introduces an intercooled and recuperated three stage, three-shaft gas turbine concept in 850 kW electric output range. The gas turbine is optimized for a realistic combination of the turbomachinery efficiencies, the turbine inlet temperature, the compressor specific speeds, the recuperation rate and the pressure ratio. The new gas turbine design is a natural development of the earlier two-spool gas turbine construction and it competes with the efficiencies achieved both with similar size reciprocating engines and large industrial gas turbines used in heat and power generation all over the world and manufactured in large production series. This paper presents a small-scale gas turbine process, which has a simulated electrical efficiency of 48% as well as thermal efficiency of 51% and can compete with reciprocating engines in terms of electrical efficiency at nominal and partial load conditions.

Solar Upgrading of Fuels for Generation of Electricity

2001 ◽  
Vol 123 (2) ◽  
pp. 160-163 ◽  
Author(s):  
Rainer Tamme ◽  
Reiner Buck ◽  
Michael Epstein ◽  
Uriyel Fisher ◽  
Chemi Sugarmen
Keyword(s):  
Gas Turbines ◽  
Large Scale ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Combined Cycle ◽  
Test Facility ◽  
Small Scale ◽  
Start Up ◽  
Efficiency Conversion ◽  
Solar Field

This paper presents a novel process comprising solar upgrading of hydrocarbons by steam reforming in solar specific receiver-reactors and utilizing the upgraded, hydrogen-rich fuel in high efficiency conversion systems, such as gas turbines or fuel cells. In comparison to conventionally heated processes about 30% of fuel can be saved with respect to the same specific output. Such processes can be used in small scale as a stand-alone system for off-grid markets as well as in large scale to be operated in connection with conventional combined-cycle plants. The complete reforming process will be demonstrated in the SOLASYS project, supported by the European Commission in the JOULE/THERMIE framework. The project has been started in June 1998. The SOLASYS plant is designed for 300 kWel output, it consists of the solar field, the solar reformer and a gas turbine, adjusted to operate with the reformed gas. The SOLASYS plant will be operated at the experimental solar test facility of the Weizmann Institute of Science in Israel. Start-up of the pilot plant is scheduled in April 2001. The midterm goal is to replace fossil fuels by renewable or non-conventional feedstock in order to increase the share of renewable energy and to establish processes with only minor or no CO2 emission. Examples might be upgrading of bio-gas from municipal solid waste as well as upgrading of weak gas resources.

Effective Decision Making in Simple and Combined Cycle Schemes at the Turn of the Millennium

1999 ◽  
Author(s):  
Stéphane Gayraud ◽  
Riti Singh
Keyword(s):  
Decision Making ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Market Potential ◽  
Load Following ◽  
Cost Planning ◽  
New Challenges ◽  
Effective Decision Making ◽  
Save Energy

The electricity supply industry is being restructured all over the world. Privatisation, with the emergence of Independent Power Projects (IPPs), especially in developing countries, and liberalisation of the power generation market are changing decision-making processes in a radical way. New challenges of deregulation and customer demands, and economic instabilities in south-east Asia, oblige electric utilities to face a double jeopardy: least-cost planning and least-risk investments. Consumers are encouraged to save energy and emission reduction policies are implemented to promote utilisation of high efficiency, clean power production technologies. The aim of this paper is to introduce the concept of life cycle risk management and Decision Support System (DSS) for open and combined cycle schemes, highlighting the market potential for Flexible Mid-size Gas Turbines (FMGT) in mid-merit applications. The DSS that has been developed at Cranfield University includes: plant simulation program, providing design and off-design performance, maintenance planning, component degradation, and load-following models. In addition several economic techniques based upon engineering finance and project accounting make power plant economic appraisals possible. The DSS also provides a Monte Carlo risk analysis in order to deal with technical and economic uncertainties in a very effective way. Case studies will stress several parameters that planners have to carefully assess when making decision in the context of the coming millennium, bringing all sorts of new challenges and areas of uncertainty that will be discussed in the paper.

Intercooled Advanced Gas Turbines in Coal Gasification Plants, With Combined or “HAT” Power Cycle

1997 ◽  
Author(s):  
Paolo Chiesa ◽  
Giovanni Lozza
Keyword(s):  
Gas Turbines ◽  
Coal Gasification ◽  
High Efficiency ◽  
Combined Cycle ◽  
Air Separation ◽  
Heavy Duty ◽  
Power Cycle ◽  
Efficiency Assessment ◽  
The One ◽  
Conversion Efficiencies

Due to their high efficiency and flexibility, aeroderivative gas turbines were often considered as a development basis for intercooled engines, thus providing better efficiency and larger power output. Those machines, originally studied for natural gas, are here considered as the power section of gasification plants for coal and heavy fuels. This paper investigates the matching between intercooled gas turbine, in complex cycle configurations including combined and HAT cycles, and coal gasification processes based on entrained-bed gasifiers, with syngas cooling accomplished by steam production or by full water-quench. In this frame, a good level of integration can be found (i.e. re-use of intercooler heat, availability of cool, pressurized air for feeding air separation units, etc.) to enhance overall conversion efficiency and to reduce capital cast. Thermodynamic aspects of the proposed systems are investigated, to provide an efficiency assessment, in comparison with mare conventional IGCC plants based on heavy-duty gas turbines. The results outline that elevated conversion efficiencies can be achieved by moderate-size intercooled gas turbines in combined cycle, while the HAT configuration presents critical development problems. On the basis of a preliminary cost assessment, cost of electricity produced is lower than the one obtained by heavy-duty machines of comparable size.

Gas Turbine Exhaust Expansion Joints, Diverter and Damper Designs for the New Generation of Higher Temperature, High Efficiency Gas Turbines

1989 ◽  
Author(s):  
Lothar Bachmann ◽  
W. Fred Koch
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Operating Conditions ◽  
High Mass ◽  
Expansion Joints ◽  
Gas Turbine Exhaust ◽  
New Generation ◽  
Turbine Exhaust

The purpose of this paper is to update the industry on the evolutionary steps that have been taken to address higher requirements imposed on the new generation combined cycle gas turbine exhaust ducting expansion joints, diverter and damper systems. Since the more challenging applications are in the larger systems, we shall concentrate on sizes from nine (9) square meters up to forty (40) square meters in ducting cross sections. (Reference: General Electric Frame 5 through Frame 9 sizes.) Severe problems encountered in gas turbine applications for the subject equipment are mostly traceable to stress buckling caused by differential expansion of components, improper insulation, unsuitable or incompatible mechanical design of features, components or materials, or poor workmanship. Conventional power plant expansion joints or dampers are designed for entirely different operating conditions and should not be applied in gas turbine applications. The sharp transients during gas turbine start-up as well as the very high temperature and high mass-flow operation conditions require specific designs for gas turbine application.

A Dry Low-NOx Gas-Turbine Combustor With Multiple-Injection Burners for Hydrogen-Rich Syngas Fuel: Testing and Evaluation of its Performance in an IGCC Pilot Plant

2013 ◽  
Author(s):  
Tomohiro Asai ◽  
Satoschi Dodo ◽  
Yasuhiro Akiyama ◽  
Akinori Hayashi ◽  
Mitsuhiro Karishuku ◽  
...  
Keyword(s):  
Pilot Plant ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Maximum Load ◽  
Combined Cycle ◽  
Multiple Injection ◽  
Injection Burner ◽  
Partial Load ◽  
Low Nox Combustion ◽  
Surrogate Fuel

Success of oxygen-blown integrated coal gasification combined cycle (IGCC) technology requires gas turbines capable of achieving dry low nitrogen oxides (NOx) combustion of hydrogen-rich syngas for low emissions and high plant efficiency. The authors have been developing a “multiple-injection burner” to achieve dry low-NOx combustion of such hydrogen-rich fuels using surrogate fuel composed of hydrogen, nitrogen, and methane. The purpose of this paper is to report test results of a multi-can combustor equipped with multiple-injection burners for a practical syngas fuel in an IGCC pilot plant and to evaluate its performance. The syngas fuel consisted of hydrogen, nitrogen, and carbon monoxide up to approximately half of its volume. In the test, the combustor achieved stable and reliable operation from ignition through partial load to the maximum load, and achieved NOx emissions of 15.1 ppm (at 15% oxygen) at the maximum load. These findings demonstrated that the combustor achieves dry low-NOx combustion of the syngas fuel in the IGCC pilot plant.

The Gas Turbine Family GT13E and GT13E2 Provides Reliable Power for Asia

1996 ◽  
Author(s):  
Gregor Gnädig
Keyword(s):  
Power Generation ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Operating Experience ◽  
Diesel Oil ◽  
Combined Cycle ◽  
Asian Countries ◽  
High Efficient ◽  
Prime Movers

Many Asian countries are experiencing economic growth which averages 5–10% per year. This environment has led to a privatization process in the power generation industry from typically state-run utilities to a system in which a federal agency oversees a market divided by private utilities and independent power producers (IPP) with the need for high efficiency, reliable power generation running on natural gas and diesel oil. In the 50 Hz market, modem, high efficient gas turbines of the type GT13E and GT13E2 have been chosen as prime movers in many combined cycle power plants in Asian countries. This paper includes a product description, and a general overview of GT13E and GT13E2 operating experience, well as an economic evaluation of a typical 500 MW combined cycle power plant.

scholarly journals Externally Fired Combined Cycles (EFCC): Part A — Thermodynamics and Technological Issues

1996 ◽  
Author(s):  
Stefano Consonni ◽  
Ennio Macchi ◽  
Francesco Farina
Keyword(s):  
Atmospheric Pressure ◽  
Gas Turbines ◽  
Large Scale ◽  
High Efficiency ◽  
Combined Cycle ◽  
Indirect Contact ◽  
Economic Issues ◽  
Combustion Gases ◽  
Combined Cycles ◽  
Gas Turbine Compressor

Externally Fired Combined Cycles (EFCC) are one of the options allowing the use of “dirty” fuels like coal, biomass or waste in conjunction with modern, high efficiency gas turbines. The plant concept comprises an indirect-contact ceramic heat exchanger where compressed air exiting the gas turbine compressor is heated by hot combustion gases; the combustor is placed downstream the turbine and operates at nearly atmospheric pressure. From a thermodynamic standpoint, the cycle is equivalent to a combined cycle with supplementary firing. Attainable efficiencies are higher than those achievable by steam cycles (even the most advanced ultra-supercritical), as well as those of most other coal-based technologies (PFBC and IGCC). These efficiency advantages must be weighted against the uncertainty (and risk) of the realization of high temperature ceramic heat exchangers, and the challenges for the design of the combustor. This two-part paper discusses thermodynamic, technological and economic issues crucial to the success of EFCCs, both for large scale utility service (3–400 MWe1 and more) and for medium/low scale applications (down to 30–50 MWe1). Part A addresses the most relevant thermodynamic and technological issues, performing comparisons with the technologies which will presumably dominate the coal-based power generation market of the next century.

Comparison of Externally Fired and Internal Combustion Gas Turbines Using Biomass Fuel

2001 ◽  
Vol 123 (4) ◽  
pp. 291-296 ◽  
Author(s):  
Sandro B. Ferreira ◽  
Pericles Pilidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
Internal Combustion ◽  
Combined Cycle ◽  
Maintenance Cost ◽  
Combustion Gas ◽  
Exhaust Temperature ◽  
Exergetic Analysis ◽  
Main Components

There is a difference of opinion regarding the relative merits of gas turbines using biomass fuels. Some engineers believe that the internal combustion gas turbine coupled to a gasifier will give a higher efficiency than the externally fired gas turbine using pretreated biomass that is not gasified. Others believe the opposite. In this paper, a comparison between these schemes is made, within the framework of the Brazilian perspective. The exergetic analysis of four cycles is described. The first cycle is externally fired (EFGT), the second uses gasified biomass as fuel (BIG/GT), each of them with a combined cycle as a variant (EFGT/CC and BIG/GTCC). These four are then compared to the natural gas turbine cycles (NGT and NGT/CC) in order to evaluate the thermodynamic cost of using biomass. The comparison is carried out in terms of thermal efficiency and in terms of exergetic efficiency and exergy destruction in the main components. The present analysis shows that the EFGT is quite promising. When compared to the NGT cycle, the EFGT gas turbine shows poor efficiency, though this parameter practically equals that of the BIG/GT cycle. The use of a bottoming steam cycle changes the figures, and the EFGT/CC—due to its higher exhaust temperature—results in high efficiency compared to the BIG/GTCC. Its lower initial and maintenance cost may be an important attraction.

Performance and Cost Analysis of Advanced Gas Turbine Cycles With Precombustion CO2 Capture

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
Stéphanie Hoffmann ◽  
Michael Bartlett ◽  
Matthias Finkenrath ◽  
Andrei Evulet ◽  
Tord Peter Ursin
Keyword(s):  
High Pressure ◽  
Power Plant ◽  
Natural Gas ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Co2 Separation ◽  
The Cost

This paper presents the results of an evaluation of advanced combined cycle gas turbine plants with precombustion capture of CO2 from natural gas. In particular, the designs are carried out with the objectives of high efficiency, low capital cost, and low emissions of carbon dioxide to the atmosphere. The novel cycles introduced in this paper are comprised of a high-pressure syngas generation island, in which an air-blown partial oxidation reformer is used to generate syngas from natural gas, and a power island, in which a CO2-lean syngas is burnt in a large frame machine. In order to reduce the efficiency penalty of natural gas reforming, a significant effort is spent evaluating and optimizing alternatives to recover the heat released during the process. CO2 is removed from the shifted syngas using either CO2 absorbing solvents or a CO2 membrane. CO2 separation membranes, in particular, have the potential for considerable cost or energy savings compared with conventional solvent-based separation and benefit from the high-pressure level of the syngas generation island. A feasibility analysis and a cycle performance evaluation are carried out for large frame gas turbines such as the 9FB. Both short-term and long-term solutions have been investigated. An analysis of the cost of CO2 avoided is presented, including an evaluation of the cost of modifying the combined cycle due to CO2 separation. The paper describes a power plant reaching the performance targets of 50% net cycle efficiency and 80% CO2 capture, as well as the cost target of 30$ per ton of CO2 avoided (2006 Q1 basis). This paper indicates a development path to this power plant that minimizes technical risks by incremental implementation of new technology.

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