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Engines (power generation and propulsion, electric vehicles)
The transient response of strained laminar-pre95/06377 mixed flames Petrov, C. and Ghoniem, A. F. Combusrion & Flame, Aug. 1995, 102, (3), 401-417. Modeling and simulation of turbulent combustion in premixed gases, for relatively large-scale and low-intensity turbulence, have traditionally been based on the assumption that the flame response to strain is instantaneous. In this paper, the authors revisit the validity of this assumption by examining the time-dependent response of a premixed laminar flame when subjected to a sudden change in strain and a periodic strain. They found that at unity Lewis number and for ste wise increase in strain, the settling time of the flame varies between the c! emical time, the flame time and the flow time as the Karlovitx number changes from low to intermediate to high values, respectively, over the entire range of flame temperatures.
95106363 Development of combined cycles In Asia Jonchere, J. P. Revue de I’Energie, Jul.-Sep. 1995, (470), 526-533. (In French) The economic situation and local circumstances have often served as explanation for Asia’s interest in combined-cycle electrical generation, as if tt was just chance that was running counter to a market that was not otherwise very lucrative. Actually, many countries of Asia are facing a situation of dire need for electricity, corresponding to their explostve growth. As this demand had to be satisfied quickly while making thrifty use of financial resources, the combined cycle (which was just emerging in the mid-eighties) was an indis nsable ally in meeting this difficult challenge. New players were also a!ele to enter the stage, as it was then possible to build small power plants of a few 100 megawatts that were competitive with the much larger nuclear and coal-fueled plants. A few examples are given, to illustrate the variety of existing situations.
Turbulent forced dlffuslon flames 95/06378 %;;$8’. S. and Li, C. Y. Combustion & Ftame, Jul. 1995, 102, (l),
95106384 An experimental lnvestlgatlon of Ll and SF, wick combustion yIi6K. Y. and Chen, L. D. Combustion & Flame, Jul. 1995, 102, (l),
For laminar diffusion flames, Spalding pioneered the evaluation of the skin friction and the burning rate in* terms of an integral approach, while Emmons obtained a similarity solution from a compressible boundary layer formualtion. Following Spalding and Emmons, the laminar theory has been extensively studied, and recent studies include also spread, wake, attachment, buoyancy, radiation, soot and geometry effects. To date, turbulent diffusion flames remained analytically untractable. It is the purpose of this study to introduce a turbulent microscale appropriate for forced diffusion flames and to propose models for fuel consumption and skin friction in terms of this scale.
10 ENGINES Power Generation and Propulsion, Electric Vehicles
Advanced turbines hold the key to economic IGCC 95106379 ModernPower Systems, Aug. 1995, t5, (8) 61, 63-64. Reports advanced IGCCS for the next dentury will utilize the next generation of advanced turbine systems to offer higher efficiencies and thus lower plant costs. For example, GE’s recently introducted H technology concept with its 60% efficiency can, according to GE, offer a nominal $100&W reduction in cost due to the twin effects of size and efficiency.
Comblned cycle Integrated wlth coal pyrolysis 95lO6360 lnstallatlon Chmielniak, T. er al., Gospod. Paliwami Energ., 1994,42, (lo), 7-10. (In Polish) The results of calculations of efficiency for coal gasification combined cycle power for different configurations of steam-gas cycle are presented.
Concepts and efflclencles of coal-flred cogenrraQSlO6361 tlon plants Wang, J. J. and Leithner, R. Brennst.-Waerme-Kraft, 1995,47, (1). 11-17. (In German) The paper discusses a comparison made of 10 coal-fired power station concepts which showed that the overall efficiency is influenced by the efficiencies of both the gas turbine and steam process. In particular, increasing the input temperature of the gas turbine gave the highest increase of overall efficiency.
95106362
Coproductlon of power, steam, and oxygen In coal or low quality fuel combustion systems Res. Disc/., 1995, 371, 181-183. The paper describes a coal gasification system and a fluid bed combustor integrated with a combined cycle gas and steam turbine power generation system. The coal is gasified with limestone and compressed air to produce a low-BTU gas which is burned in a gas turbine combustor. Additional coal is combusted with air and limestone in a fluid bed combustor to generate steam, the hot pressurized top gas from the fluid be combustor is sent to a gas turbine combustor with additional compressed air for further combustion, and the pressure energy of the resulting combustion product is recovered in the gas turbine.
- . An experimental study of a novel liquid-metal combustion system involving the reaction of lithium (Li; fuel species) and sulphur-hexafluoride (SF,; oxidizer species) is reported in this paper. The liquid-metal combustion system is also known as the SCEPS system (Stored Chemical Energy Propulsion Systems). The combustion products (LiF and Li,S) are soluble in liquid lithium. Two immiscible liquids, fuel-rich (or metal-rich) and product-rich (or salt rich) liquids are formed following the combustion. The density of the product-nch liquid is heavier than the fuel-rich (or pure lithium) liquid. This property allows for a closed-system operation. The system is unique in that it has a high energy density and a high specific energy, and that it yields condensed-phase products under normal operating conditions. 95106365
First Industrial scale CYMIC at Rauma
Modern Power Systems, Aug. 1995, 15, (S), 47, 49, 51, 53, 55-56.
Describes a 160 MW cogeneration plant which is being installed to provide recess steam and electricity for United Paper Mill’s Rauma pa er mill in $.Inland . The installation will be the first industrial scale adof!rcation of Tampella Power’s CYMIC space saving boiler. A key to the efficient operation of the plant is the use of a state-of-the-art distributed control system supplyed by Valmet Automation. High-temperature coatings for protectlon agalnst 95lO6366 turblno deterloratlon Tabakoff, W. et al., J. Eng. Gas Turbines Power, 1995,117, (l), 146-151. An investigation was conducted to study the fly ash particles associated with the erosion behaviour of alloys and coatings that-are widely used in gas and steam turbines. The erosion behaviour of alloys and protective coatings has been investigated experimentally at high temperatures using a specially designed wind erosion tunnel. The results obtained show the effect of velocity, temperature, and impact angle on the erosion rate. The Impacts of large scale use of rlectrlc vehicles 95106367 In southern Callfornla Ford. A. Energy & Build., 1995, 22, (3). 207-218. This-article summarizes a re ort to the Calfomia Institute for Energy Effrciency on The Impact of B lectric Vehicles on the Southern California Edison System. It then describes the assumptions adopted for eight scenarios with large scale use of electric vehicles in southern California. The article then exolains the likelv imoacts of these vehicles on Edison’s electric loads, its system operatioh, it; total revenue requirements and its average electric rate. The study confirms that electric vehicles can lead to im roved load shapes, improved efficiency of operations, and a possible re8uction in the average electric rate. Industry attitudes to combined cycle clean coal 95106366 technologies: Survey of current status Internatinoal Energy Agency, Coal Industry Advisory Boafd OECDIIEA,
2 Rue Andre Pascal, 75775 Paris Cedex 16, France, 40 pp. Outlines the current status of coal combined cycle technologies for power generation, which are approaching commercialisation. Gives a summary of the attitudes of the industry toward their development as expressed by senior executives of electricity utilities, coal producers, and combustion equipment manufacturers, most of whom are members of the Coal Industry Advisory Board. Inert gases to reduce emlsslons and Improve Inte95106369 grated gaslflcatlon combined cycle performance Griffiths, J. and Landaelv, I. Proc. Inst. Mech. Eng., IMechE Conf, UK, 1994, (7), 155-167. The paper examines a group of Integrated Gasification Combined Cycle (IGCC) flow schemes being incorporated in current power generation projects. The common feature is the injection or production of inert (nonflammable) gases to both reduce NO, and SO, emissions and, at the same time, to increase output and/or efficiency without an increase in unit investment.
Fuel and Energy Abstracts November 1995 451