The Chronological Development of the Cheng Cycle Steam Injected Gas Turbine During the Past 25 Years

Author(s):  
Dah Yu Cheng ◽  
Albert L. C. Nelson

The Cheng Cycle gas turbine has enjoyed its 25th anniversary since its conception. More than 100 sites around the world including the United States, Japan, Australia, Italy, Germany, and the Netherlands have used the Cheng Cycle. A chronology will be presented in this paper which will highlight the steps taken to develop the fully automated, load following power and cogeneration system. The Cheng cycle operates with a steam to air ratio trajectory that has its highest “peak efficiency” at the onset of a turbine’s operation. The peak efficiency point was coined as the Cheng point by Dr. Urbach [ref.1] of the US Navy’s David Taylor Research Center. Many thermodynamic and professional textbooks refer to the original Dual Fluid Cycle as the Cheng Cycle. Besides the high efficiency feature, the Cheng Cycle is mechanically simple and flexible in operation. It can put power on line faster than a combined cycle, and it has extremely clean emissions at low cost. The future performance of the Advanced Cheng Cycle will also be projected.

Author(s):  
Christian L. Vandervort ◽  
Mohammed R. Bary ◽  
Larry E. Stoddard ◽  
Steven T. Higgins

The Externally-Fired Combined Cycle (EFCC) is an attractive emerging technology for powering high efficiency combined gas and steam turbine cycles with coal or other ash bearing fuels. The key near-term market for the EFCC is likely to be repowering of existing coal fueled power generation units. Repowering with an EFCC system offers utilities the ability to improve efficiency of existing plants by 25 to 60 percent, while doubling generating capacity. Repowering can be accomplished at a capital cost half that of a new facility of similar capacity. Furthermore, the EFCC concept does not require complex chemical processes, and is therefore very compatible with existing utility operating experience. In the EFCC, the heat input to the gas turbine is supplied indirectly through a ceramic heat exchanger. The heat exchanger, coupled with an atmospheric coal combustor and auxiliary components, replaces the conventional gas turbine combustor. Addition of a steam bottoming plant and exhaust cleanup system completes the combined cycle. A conceptual design has been developed for EFCC repowering of an existing reference plant which operates with a 48 MW steam turbine at a net plant efficiency of 25 percent. The repowered plant design uses a General Electric LM6000 gas turbine package in the EFCC power island. Topping the existing steam plant with the coal fueled EFCC improves efficiency to nearly 40 percent. The capital cost of this upgrade is 1,090/kW. When combined with the high efficiency, the low cost of coal, and low operation and maintenance costs, the resulting cost of electricity is competitive for base load generation.


Author(s):  
Joseph Sinai ◽  
Chemi Sugarmen ◽  
Uriyel Fisher

Adapting a gas turbine to high-temperature solar receivers and solar tower technology constitutes real progress towards commercial solar power utilization with high efficiency combined cycle power system. Solar gas turbine systems can also be adapted to hybrid solar/fossil fuel operation, thanks to its high efficiency conversion, relatively small solar field, and quick response to load fluctuations, low CO2 emissions, easy start, and more effective equipment utilization. ORMAT initiated adaptation and modification of gas turbines for solar energy applications in the early 1990s in cooperation with the Weizmann Institute of Science and later with the Boeing Corporation, with the support of the United States Israel Science and Technology Foundation (USISTF). Ultimately, the concept reached its successful realization (2001–2004) in the solar tower Plataforma Solar de Almeria (Spain) which has three solar receivers and a receiving system designed and supplied by the German Aerospace Center DLR.


Author(s):  
Takao Sugimoto ◽  
Katsushi Nagai ◽  
Masanori Ryu ◽  
Ryozo Tanaka ◽  
Takeshi Kimura ◽  
...  

The L20A gas turbine is a newly developed 20 MW class single-shaft machine. With its high simple-cycle efficiency and high exhaust gas temperature, it is particularly suited for use in distributed power generation, cogeneration and combined cycle applications. A design philosophy has been adopted for the turbine which includes a high efficiency transonic axial-flow compressor with eight can-type combustors and a high inlet temperature of 1250°C. This results in a thermal efficiency of 35% and an overall thermal efficiency of 80% for cogeneration system. In addition, the NOx emissions from the combustor is low and the L20A has a long service life. These features permit long-term continuous operation under various environmental limitations. Due to the engine’s high efficiency and its low component totals, the lowest life cycle cost is achieved. Development testing has verified that the performance, the mechanical characteristics and the emission have satisfied the initial design goals. The engine has been in operation from November 2001 as the first operating unit in a co-generation system at Kawasaki Akashi Works.


2011 ◽  
Vol 133 (05) ◽  
pp. 30-33 ◽  
Author(s):  
Lee S. Langston

This article explores the increasing use of natural gas in different turbine industries and in turn creating an efficient electrical system. All indications are that the aviation market will be good for gas turbine production as airlines and the military replace old equipment and expanding economies such as China and India increase their air travel. Gas turbines now account for some 22% of the electricity produced in the United States and 46% of the electricity generated in the United Kingdom. In spite of this market share, electrical power gas turbines have kept a much lower profile than competing technologies, such as coal-fired thermal plants and nuclear power. Gas turbines are also the primary device behind the modern combined power plant, about the most fuel-efficient technology we have. Mitsubishi Heavy Industries is developing a new J series gas turbine for the combined cycle power plant market that could achieve thermal efficiencies of 61%. The researchers believe that if wind turbines and gas turbines team up, they can create a cleaner, more efficient electrical power system.


2013 ◽  
Vol 320 ◽  
pp. 768-773
Author(s):  
Tien Kuei Yu

A technical computer animation for dynamic film, animated short film production to Taiwan by customers to move to the development of the continent, a shrinking market worries. Visible the Taiwan in animation foundry (low-cost, high-quality, high-efficiency) industry, no longer is an advantage. The other hand, the industry has also been realized to cartoons of the United States and Japan and therefore positive efforts (toward the direction of home-made animation Fanmei Jun, 2004). Secondly, the computer animation at this stage of the development of animation industry in Taiwan is the weakest that is, the ability of the financial, legal, and international marketing. Due to the creation of the marketing practices of the finished product is difficult to both creators oriented (Hongfeng Yi, 2004). The research basis the Tsou-Hsiang Ju (2008) using conjoint analysis, analysis of four different preference cluster analysis, five kinds of film properties and their rights, grey relational analysis of dynamic video library field to be named; understand the Hall field the eyes of the average consumer selection situation, it is recommended to design products to meet consumer preferences, and to continue to innovate and reform, driven by the digital content industry to flourish in the international market and to keep pace with foreign manufacturers.


Author(s):  
R. Chacartegui ◽  
D. Sa´nchez ◽  
F. Jime´nez-Espadafor ◽  
A. Mun˜oz ◽  
T. Sa´nchez

The development of high efficiency solar power plants based on gas turbine technology presents two problems, both of them directly associated with the solar power plant receiver design and the power plant size: lower turbine intake temperature and higher pressure drops in heat exchangers than in a conventional gas turbine. To partially solve these problems, different configurations of combined cycles composed of a closed cycle carbon dioxide gas turbine as topping cycle have been analyzed. The main advantage of the Brayton carbon dioxide cycle is its high net shaft work to expansion work ratio, in the range of 0.7–0.85 at supercritical compressor intake pressures, which is very close to that of the Rankine cycle. This feature will reduce the negative effects of pressure drops and will be also very interesting for cycles with moderate turbine inlet temperature (800–1000 K). Intercooling and reheat options are also considered. Furthermore, different working fluids have been analyzed for the bottoming cycle, seeking the best performance of the combined cycle in the ranges of temperatures considered.


1974 ◽  
Author(s):  
N. R. Dibelius ◽  
George Touchton ◽  
Thomas Kane

This paper contains the calculated ground level concentrations of air pollutants from 11 gas turbine models. These calculations were made using Charlotte, N.C. meteorological data. Four of these are simple cycle machines covering a range of size from 5050 hp to 65 MW and four are regenerative machines. Another three are combined cycle (STAG) machines, two machines having unfired and one having a fired heat recovery steam generator. The calculations were made using a slightly modified version of the United States Environmental Protection Agencies Air Quality Display Model Computer Program.


Author(s):  
Stéphane Gayraud ◽  
Riti Singh

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.


Author(s):  
Mauro Reini

In recent years, a big effort has been made to improve microturbines thermal efficiency, in order to approach 40%. Two main options may be considered: i) a wide usage of advanced materials for hot ends components, like impeller and recuperator; ii) implementing more complicated thermodynamic cycle, like combined cycle. In the frame of the second option, the paper deals with the hypothesis of bottoming a low pressure ratio, recuperated gas cycle, typically realized in actual microturbines, with an Organic Rankine Cycle (ORC). The object is to evaluate the expected nominal performance parameters of the integrated-combined cycle cogeneration system, taking account of different options for working fluid, vapor pressure and component’s performance parameters. Both options of recuperated and not recuperated bottom cycles are discussed, in relation with ORC working fluid nature and possible stack temperature for microturbine exhaust gases. Finally, some preliminary consideration about the arrangement of the combined cycle unit, and the effects of possible future progress of gas cycle microturbines are presented.


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