Development of Ni-Based DS Superalloy with Excellent Oxidation Resistance and LCF Properties for Power-Generation Gas Turbines

2012 ◽  
pp. 255-263 ◽  
Author(s):  
Akira Yoshinari ◽  
Osam Tamura ◽  
Yoshinori Murata ◽  
Masahiko Morinaga
2020 ◽  
Vol 40 (9) ◽  
pp. 759-762
Author(s):  
V. M. Kraev ◽  
A. I. Tikhonov ◽  
M. V. Siluyanova

Author(s):  
Elliot Sullivan-Lewis ◽  
Vincent McDonell

Lean-premixed gas turbines are now common devices for low emissions stationary power generation. By creating a homogeneous mixture of fuel and air upstream of the combustion chamber, temperature variations are reduced within the combustor, which reduces emissions of nitrogen oxides. However, by premixing fuel and air, a potentially flammable mixture is established in a part of the engine not designed to contain a flame. If the flame propagates upstream from the combustor (flashback), significant engine damage can result. While significant effort has been put into developing flashback resistant combustors, these combustors are only capable of preventing flashback during steady operation of the engine. Transient events (e.g., auto-ignition within the premixer and pressure spikes during ignition) can trigger flashback that cannot be prevented with even the best combustor design. In these cases, preventing engine damage requires designing premixers that will not allow a flame to be sustained. Experimental studies were conducted to determine under what conditions premixed flames of hydrogen and natural gas can be anchored in a simulated gas turbine premixer. Tests have been conducted at pressures up to 9 atm, temperatures up to 750 K, and freestream velocities between 20 and 100 m/s. Flames were anchored in the wakes of features typical of premixer passageways, including cylinders, steps, and airfoils. The results of this study have been used to develop an engineering tool that predicts under what conditions a flame will anchor, and can be used for development of flame anchoring resistant gas turbine premixers.


Author(s):  
Illias Hischier ◽  
Pascal Leumann ◽  
Aldo Steinfeld

A high-temperature pressurized air-based receiver for power generation via solar-driven gas turbines is experimentally and theoretically examined. It consists of an annular reticulate porous ceramic (RPC) foam concentric with an inner cylindrical cavity-receiver exposed to concentrated solar radiation. Absorbed heat is transferred by combined conduction, radiation, and convection to the pressurized air flowing across the RPC. The governing steady-state mass, momentum and energy conservation equations are formulated and solved numerically by coupled Finite Volume and Monte Carlo techniques. Validation is accomplished with experimental results using a 1 kW solar receiver prototype subjected to average solar radiative fluxes in the range 1870–4360 kW m−2. Experimentation was carried out with air and helium as working fluids, heated from ambient temperature up to 1335 K at an absolute operating pressure of 5 bars.


Author(s):  
Matti Malkamäki ◽  
Ahti Jaatinen-Värri ◽  
Antti Uusitalo ◽  
Aki Grönman ◽  
Juha Honkatukia ◽  
...  

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.


Author(s):  
Mark A. Paisley ◽  
Donald Anson

The Biomass Power Program of the US Department of Energy (DOE) has as a major goal the development of cost-competitive technologies for the production of power from renewable biomass crops. The gasification of biomass provides the potential to meet his goal by efficiently and economically producing a renewable source of a clean gaseous fuel suitable for use in high efficiency gas turbines. This paper discusses the development and first commercial demonstration of the Battelle high-throughput gasification process for power generation systems. Projected process economics are presented along with a description of current experimental operations coupling a gas turbine power generation system to the research scale gasifier and the process scaleup activities in Burlington, Vermont.


Author(s):  
Wolfgang Kappis ◽  
Stefan Florjancic ◽  
Uwe Ruedel

Market requirements for the heavy duty gas turbine power generation business have significantly changed over the last few years. With high gas prices in former times, all users have been mainly focusing on efficiency in addition to overall life cycle costs. Today individual countries see different requirements, which is easily explainable picking three typical trends. In the United States, with the exploitation of shale gas, gas prices are at a very low level. Hence, many gas turbines are used as base load engines, i.e. nearly constant loads for extended times. For these engines reliability is of main importance and efficiency somewhat less. In Japan gas prices are extremely high, and therefore the need for efficiency is significantly higher. Due to the challenge to partly replace nuclear plants, these engines as well are mainly intended for base load operation. In Europe, with the mid and long term carbon reduction strategy, heavy duty gas turbines is mainly used to compensate for intermittent renewable power generation. As a consequence, very high cyclic operation including fast and reliable start-up, very high loading gradients, including frequency response, and extended minimum and maximum operating ranges are required. Additionally, there are other features that are frequently requested. Fuel flexibility is a major demand, reaching from fuels of lower purity, i.e. with higher carbon (C2+), content up to possible combustion of gases generated by electrolysis (H2). Lifecycle optimization, as another important request, relies on new technologies for reconditioning, lifetime monitoring, and improved lifetime prediction methods. Out of Alstom’s recent research and development activities the following items are specifically addressed in this paper. Thermodynamic engine modelling and associated tasks are discussed, as well as the improvement and introduction of new operating concepts. Furthermore extended applications of design methodologies are shown. An additional focus is set ono improve emission behaviour understanding and increased fuel flexibility. Finally, some applications of the new technologies in Alstom products are given, indicating the focus on market requirements and customer care.


2017 ◽  
Vol 1 ◽  
pp. K4MD26 ◽  
Author(s):  
Seyfettin C. Gülen

AbstractThis article evaluates the improvement in gas turbine combined cycle power plant efficiency and output via pressure gain combustion (PGC). Ideal and real cycle calculations are provided for a rigorous assessment of PGC variants (e.g., detonation and deflagration) in a realistic power plant framework with advanced heavy-duty industrial gas turbines. It is shown that PGC is the single-most potent knob available to the designers for a quantum leap in combined cycle performance.


2012 ◽  
Vol 6 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Marcio L. de Souza-Santos ◽  
Juan Villanueva Chavez

Following a preliminary study of power generation processes consuming sugar-cane bagasse; this second round indicates the possibility of almost doubling the current efficiency presently obtained in conventional mills. A combined cycle uses highly pressurized fluidized bed boiler to provide steam above critical temperature to drive steam-turbine cycle while the flue-gas is injected into gas turbines. The present round also shows that gains over usual BIG/GT (Biomass In-tegrated Gasification/Gas Turbine) are very likely mainly due to the practicality of feeding the biomass as slurry that can be pumped into the pressurized boiler chamber. Such would avoid the cumbersome cascade feeding of the fibrous bio-mass, usually required by other processes. The present stage assumes slurry with 50% added water. Future works will concentrate on thicker slurries, if those could be achieved. All studies apply a comprehensive simulator for boilers and gasifiers [CSFMB™ or CeSFaMB™] and a process simulator (IPES) to predict the main features of the steam and gas tur-bine branches.


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