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.

Conjugate Simulation of the Effects of Oxide Formation in Effusion Cooling Holes on Cooling Effectiveness

2009 ◽  
Author(s):  
Dieter Bohn ◽  
Robert Krewinkel
Keyword(s):  
Gas Turbines ◽  
Power Plants ◽  
Gas Flow ◽  
Combined Cycle ◽  
Reference Case ◽  
Flow Area ◽  
Cooling Effectiveness ◽  
Hot Gas ◽  
Barrier Coating ◽  
Cooling Hole

Within Collaborative Research Center 561 “Thermally Highly Loaded, Porous and Cooled Multi-Layer Systems for Combined Cycle Power Plants” at RWTH Aachen University an effusion-cooled multi-layer plate configuration with seven staggered effusion cooling holes is investigated numerically by application of a 3-D in-house fluid flow and heat transfer solver, CHTflow. The effusion-cooling is realized by finest drilled holes with a diameter of 0.2 mm that are shaped in the region of the thermal barrier coating. Oxidation studies within SFB 561 have shown that a corrosion layer of several oxides with a thickness of appoximately 20μm grows from the CMSX-4 substrate into the cooling hole. The goal of this work is to investigate the effect this has on the cooling effectiveness, which has to be quantified prior to application of this novel cooling technology in real gas turbines. In order to do this, the influence on the aerodynamics of the flow in the hole, on the hot gas flow and the cooling effectiveness on the surface and in the substrate layer are discussed. The adverse effects of corrosion on the mechanical strength are not a part of this study. A hot gas Mach-number of 0.25 and blowing ratios of approximately 0.28 and 0.48 are considered. The numerical grid contains the coolant supply (plenum), the solid body for the conjugate calculations and the main flow area on the plate. It is shown that the oxidation layer does significantly affect the flow field in the cooling holes and on the plate, but the cooling effectiveness differs only slightly from the reference case. This seems to justify modelling the holes without taking account of the oxidation.

Through Flow Flange-to-Flange Turbine and Diffuser Analysis

2012 ◽  
Author(s):  
Andrei Granovskiy ◽  
Mikhail Kostege ◽  
Vladislav Krupa ◽  
Sergey Rudenko
Keyword(s):  
Gas Turbines ◽  
Power Plants ◽  
Gas Flow ◽  
Optimal Solution ◽  
Integrated Approach ◽  
Combined Cycle ◽  
Navier Stokes ◽  
Local Flow ◽  
Flow Angle ◽  
Part Load

At the present time an important aspect of power generation in combined cycle power plants is to keep part load performance of heavy duty gas turbines sufficiently high. Therefore it is a matter of importance to ensure the aerodynamic alignment between the turbine and exhaust diffuser, allowing potential increase in both turbine efficiency and diffuser pressure recovery. The benefit of such alignment could be noticed at numerical analysis accuracy of part-load conditions in particular due to the change in gas flow angle downstream of the turbine and resulting in an incidence on the diffuser struts. This incidence, in its turn, often causes local flow separation and an associated loss increase. This paper presents an integrated approach of the turbine and diffuser aerodynamic design by means of use of a single 3D Navier-Stokes CFD model. This model explores an automatic interface between the turbine and diffuser calculation domains. Furthermore, whilst gas turbine part load performance has been improved thanks to last stage turbine blade redesign, the above-mentioned integrated turbine & diffuser numerical modelling was used as working instrument to reach the optimal solution in terms of flange-to-flange efficiency in a broad operation range. Following test results, comparison against the numerical prediction fully proved the validity of chosen analytical approach.

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.

The Effect of Alternative Turbine Cooling Schemes on the Performance of Utility Gas Turbine Powerplants

1982 ◽  
Author(s):  
Arthur Cohn ◽  
Mark Waters
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Power Plants ◽  
Heat Rate ◽  
Combined Cycle ◽  
Specific Power ◽  
Cooling Effectiveness ◽  
Turbine Cooling ◽  
The Impact ◽  
Systems Studies

It is important that the requirements and cycle penalties related to the cooling of high temperature turbines be thoroughly understood and accurately factored into cycle analyses and power plant systems studies. Various methods used for the cooling of high temperature gas turbines are considered and cooling effectiveness curves established for each. These methods include convection, film and transpiration cooling using compressor bleed and/or discharge air. In addition, the effects of chilling the compressor discharge cooling gas are considered. Performance is developed to demonstrate the impact of the turbine cooling schemes on the heat rate and specific power of Combined–Cycle power plants.

300 MW Combined-Cycle Plant With Integrated Coal Gasification

1984 ◽  
Author(s):  
Rolf H. Kehlhofer
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbines ◽  
Power Plants ◽  
Coal Gasification ◽  
District Heating ◽  
Combined Cycle ◽  
Liquid Fuels ◽  
Combined Cycle Plant ◽  
The Individual

In the past 15 years the combined-cycle (gas/steam turbine) power plant has come into its own in the power generation market. Today, approximately 30 000 MW of power are already installed or being built as combined-cycle units. Combined-cycle plants are therefore a proven technology, showing not only impressive thermal efficiency ratings of up to 50 percent in theory, but also proving them in practice and everyday operation (1) (2). Combined-cycle installations can be used for many purposes. They range from power plants for power generation only, to cogeneration plants for district heating or combined cycles with maximum additional firing (3). The main obstacle to further expansion of the combined cycle principle is its lack of fuel flexibility. To this day, gas turbines are still limited to gaseous or liquid fuels. This paper shows a viable way to add a cheap solid fuel, coal, to the list. The plant system in question is a 2 × 150 MW combined-cycle plant of BBC Brown Boveri with integrated coal gasification plant of British Gas/Lurgi. The main point of interest is that all the individual components of the power plant described in this paper have proven their worth commercially. It is therefore not a pilot plant but a viable commercial proposition.

Graph Theoretic Analysis of Advance Combined Cycle Power Plants Alternatives With Latest Gas Turbines

2013 ◽  
Author(s):  
Nikhil Dev ◽  
Gopal Krishan Goyal ◽  
Rajesh Attri ◽  
Naresh Kumar
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Real Life ◽  
Combined Cycle ◽  
Turbine Engines ◽  
Steam Generation ◽  
Graph Theoretic ◽  
Early Decision

In the present work, graph theory and matrix method is used to analyze some of the heat recovery possibilities with the newly available gas turbine engines. The schemes range from dual pressure heat recovery steam generation systems, to triple pressure systems with reheat in supercritical steam conditions. From the developed methodology, result comes out in the form of a number called as index. A real life operating Combined Cycle Power Plant (CCPP) is a very large and complex system. Efficiency of its components and sub-systems are closely intertwined and insuperable without taking the effect of others. For the development of methodology, CCPP is divided into six sub-systems in such a way that no sub-system is independent. Digraph for the interdependencies of sub-system is organized and converted into matrix form for easy computer processing. The results obtained with present methodology are in line with the results available in literature. The methodology is developed with a view that power plant managers can take early decision for selection, improvements and comparison, amongst the various options available, without having in-depth knowledge of thermodynamics analysis.

Turning NGCC Into IGCC: Cycle Retrofitting Issues

2006 ◽  
Author(s):  
Juan Pablo Gutierrez ◽  
Terry B. Sullivan ◽  
Gerald J. Feller
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Integrated Gasification Combined Cycle ◽  
Water Steam ◽  
Power Block ◽  
Starting Point ◽  
Natural Gas Combined Cycle ◽  
Gas Plants

The increase in price of natural gas and the need for a cleaner technology to generate electricity has motivated the power industry to move towards Integrated Gasification Combined Cycle (IGCC) plants. The system uses a low heating value fuel such as coal or biomass that is gasified to produce a mixture of hydrogen and carbon monoxide. The potential for efficiency improvement and the decrease in emissions resulting from this process compared to coal-fired power plants are strong evidence to the argument that IGCC technology will be a key player in the future of power generation. In addition to new IGCC plants, and as a result of new emissions regulations, industry is looking at possibilities for retrofitting existing natural gas plants. This paper studies the feasibility of retrofitting existing gas turbines of Natural Gas Combined Cycle (NGCC) power plants to burn syngas, with a focus on the water/steam cycle design limitations and necessary changes. It shows how the gasification island processes can be treated independently and then integrated with the power block to make retrofitting possible. This paper provides a starting point to incorporate the gasification technology to current natural gas plants with minor redesigns.

Design of Fast and Reliable Steam Surface Condensers

2020 ◽  
Author(s):  
Ranga Nadig
Keyword(s):  
Steam Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Design Features ◽  
Surface Condenser ◽  
Combined Cycle Plant ◽  
Startup Time ◽  
On Line ◽  
To Come

Abstract Power plants operating in cyclic mode, standby mode or as back up to solar and wind generating assets are required to come on line on short notice. Simple cycle power plants employing gas turbines are being designed to come on line within 10–15 minutes. Combined cycle plants with heat recovery steam generators and steam turbines take longer to come on line. The components of a combined cycle plant, such as the HRSG, steam turbine, steam surface condenser, cooling tower, circulating water pumps and condensate pumps, are being designed to operate in unison and come on line expeditiously. Major components, such as the HRSG, steam turbine and associated steam piping, dictate how fast the combined cycle plant can come on line. The temperature ramp rates are the prime drivers that govern the startup time. Steam surface condenser and associated auxiliaries impact the startup time to a lesser extent. This paper discusses the design features that could be included in the steam surface condenser and associated auxiliaries to permit quick startup and reliable operation. Additional design features that could be implemented to withstand the demanding needs of cyclic operation are highlighted.

Overall Performance of Advanced H2/Air Cycle Power Plants Based on Coal Decarbonisation

2005 ◽  
Author(s):  
M. Gambini ◽  
M. Vellini
Keyword(s):  
Power Plant ◽  
Hydrogen Production ◽  
Power Plants ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Fuel Gas ◽  
Production Section ◽  
Pinch Technology ◽  
Energy Economy ◽  
Overall Performance

In this paper the overall performance of a new advanced mixed cycle (AMC), fed by hydrogen-rich fuel gas, has been evaluated. Obviously, hydrogen must be produced and here we have chosen the coal gasification for its production, quantifying all the thermal and electric requirements. At first, a simple combination between hydrogen production section and power section is performed. In fact, the heat loads of the first section can be satisfied by using the various raw syngas cooling, without using some material streams taken from the power section, but also without using part of heat, available in the production section and rejected into the environment, in the power section. The final result is very poor: over 34%. Then, by using the Pinch Technology, a more efficient, even if more complex, solution can be conceived: in this case the overall efficiency is very interesting: 39%. These results are very similar to those of a combined cycle power plant, equipped with the same systems and analyzed under the same hypotheses. The final result is very important because the “clean” use of coal in new power plant types must be properly investigated: in fact coal is the most abundant and the cheapest fossil fuel available on earth; moreover, hydrogen production, by using coal, is an interesting outlook because hydrogen has the potential to become the main energy carrier in a future sustainable energy economy.

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