scholarly journals Coal-Fired Magnetohydrodynamic Power Plant With Zero-CO2 Atmospheric Emission

1997 ◽  
Author(s):  
E. Iantovski ◽  
R. Lhomme ◽  
Ph. Mathieu
Keyword(s):  
Power Plant ◽  
High Performance ◽  
Combustion Process ◽  
The Other ◽  
Working Fluid ◽  
Atmospheric Emission ◽  
Mhd Generator ◽  
Energy Consuming ◽  
The One ◽  
Cycle Efficiency

In this system, an MHD generator is used instead of a gas turbine. The cycle efficiency is reaching 50%. The system is based on a cycle using CO2 as the working fluid and oxygen as oxidant. The fuel is pulverized coal. All the pollutants, including the CO2 produced in the combustion process, are fully removed and diposed of. This highly pressurized excess CO2 is easily separated from the working fluid without any costly and energy consuming device and, being in liquid state, is ready for transportation and disposal or possibly reuse in other applications. The most important parameter determining the cycle efficiency is shown to be the isentropic effectiveness of the MHD expander. This latter is depending, on the one hand, on the design of the channel and on the other hand, on the conductivity of the gases which can be optimized with respect to the cycle parameters. In conclusion, the assets of the proposed system are high performance and no pollutant releases. As a consequence, MHD generators may be considered as viable options for coal-firing and possible competitors of advanced coal-based plants. One of the spin-off of this study is the possible revival of existing MHD facilities.

Analytical Study of the Effects of the Clogging of a Mechanical Precipitator Unit in Air Preheaters in a High-Performance Thermoelectric Power Plant Based on Available Data

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
J. M. Blanco ◽  
F. Peña
Keyword(s):  
Power Plant ◽  
Thermoelectric Power ◽  
High Performance ◽  
Gas Flow ◽  
Analytical Study ◽  
The Other ◽  
Analytical Analysis ◽  
The One ◽  
Very High ◽  
Thermoelectric Power Plant

Following a detailed study of two of the mechanical precipitators in the air preheaters of a thermoelectric power plant, a large amount of ash that was deposited on one of the inlet conduits was observed, obstructing the incoming gas flow. A comparison of the available data for the two most recent hopper cleaning operations revealed that, on the one hand, the amount of ash collected by the clogged precipitator (A) was significantly less than that collected by the other (B) and, on the other hand, the temperature of the ash in the former was noticeably lower than in the latter. Prior to the cleaning of the conduits, a certain amount of damage was caused to the boiler dome, which meant that subsequent cleaning required the use of a hydrolazer, where it was noted that inlet pressures were very high. All of this indicated that the cause of the clogging was not physical. This paper provides a comprehensive analytical analysis that explains what happened, as well as resolving the situation.

Performance Assessment of Semi-Closed Chemically Recuperated Gas Turbine Systems

2000 ◽  
Author(s):  
Giorgio Cau ◽  
Daniele Cocco
Keyword(s):  
Gas Turbine ◽  
System Analysis ◽  
Combustion Process ◽  
Pure Oxygen ◽  
Specific Power ◽  
Working Fluid ◽  
Exhaust Heat ◽  
And Performance ◽  
Polluting Emissions ◽  
Cycle Efficiency

The paper is concerned with thermochemical recuperation in semi-closed gas turbine systems. Semi-closed turbines use CO2 as the main working fluid and the combustion process takes place with pure oxygen, allowing the CO2 produced to be easily removed. On the other hand, the exhaust heat recovery through thermochemical recuperation offers interesting capabilities in terms of high conversion efficiency and low polluting emissions. System analysis and performance evaluation of the semi-closed, chemically recuperated gas turbine systems has been conducted and their performance assessed. A comparative analysis of semi-closed and open gas turbine cycles, with and without thermochemical recuperation, has been also carried out. The results of the analysis show that thermochemical recuperation in semi-closed gas turbine systems can allow to remove the CO2 with high cycle efficiency and specific power.

Zero-Emission MATIANT Cycle

1999 ◽  
Vol 121 (1) ◽  
pp. 116-120 ◽  
Author(s):  
P. Mathieu ◽  
R. Nihart
Keyword(s):  
Gas Turbines ◽  
Co2 Emission ◽  
Combustion Process ◽  
Advanced Materials ◽  
Working Fluid ◽  
Brayton Cycle ◽  
Combustion Chambers ◽  
Novel Technology ◽  
Technical Issues ◽  
Cycle Efficiency

In this paper, a novel technology based on the zero CO2 emission MATIANT (contraction of the names of the two designers MAThieu and IANTovski) cycle is presented. This latter is basically a gas cycle and consists of a supercritical CO2 Rankine-like cycle on top of regenerative CO2 Brayton cycle. CO2 is the working fluid and O2 is the fuel oxidizer in the combustion chambers. The cycle uses the highest temperatures and pressures compatible with the most advanced materials in the steam and gas turbines. In addition, a reheat and a staged compression with intercooling are used. Therefore, the optimized cycle efficiency rises up to around 45 percent when operating on natural gas. A big asset of the system is its ability to remove the CO2 produced in the combustion process in liquid state and at high pressure, making it ready for transportation, for reuse or for final storage. The assets of the cycle are mentioned. The technical issues for the predesign of a prototype plant are reviewed.

Prediction of the Lifetime of Acrylonitrile Butadiene Styrene (ABS), by Calculation of Damage by Two Methods: Damage Based on Residual Stresses and Damage by Stages Evolution

2019 ◽  
Vol 820 ◽  
pp. 203-211
Author(s):  
Fatima Sabah ◽  
Achraf Wahid ◽  
Fatimaezzahra Nassih ◽  
Mohamed El Ghorba ◽  
Hamid Chakir
Keyword(s):  
Experimental Study ◽  
High Performance ◽  
Elastic Limit ◽  
Mechanical Characteristics ◽  
Acrylonitrile Butadiene Styrene ◽  
The Other ◽  
Stress Maximum ◽  
The One ◽  
Geometrical Defects ◽  
Butadiene Styrene

The development of polymers has not stopped growing and taking more and more emphasis in our lives. From high-performance industries to mass-market industries, polymers are ubiquitous in every aspect of our lives, from where comes the pressing need to know their properties, characteristics, and behaviors more rigorously. This work is based on a study of the mechanical characterizations of thermoplastic polymers under the effects of damage. To serve this purpose, an experimental study was carried out on thermoplastic ABS (Acrylonitrile Butadiene Styrene) specimens. At first, we worked on altered specimens to define the mechanical characteristics of our material such as the elastic limit, the stress maximum, the breaking stress and the Young's modulus. On the one hand, and on the other hand we have created geometrical defects (discontinuity) on specimens in (ABS), to have the effect of defects on the mechanical characteristics of the material, afterwards a study of damage carried out by two methods to determine the critical fraction of life. To determine the lifetime of the ABS.

scholarly journals Improvement of Combustion Process of Spark-Ignited Aviation Wankel Engine

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2292 ◽  
Author(s):  
Lev Finkelberg ◽  
Alexander Kostuchenkov ◽  
Andrei Zelentsov ◽  
Vladimir Minin
Keyword(s):  
Cross Sections ◽  
High Performance ◽  
Laminar Flame ◽  
Combustion Process ◽  
Working Fluid ◽  
Piston Engine ◽  
Computational Region ◽  
Rotor Design ◽  
Wankel Engine ◽  
The Mathematical Model

This paper deals with the creation of modern high-performance aircraft power units based on the Wankel rotary piston engine. One of the main problems of Wankel engines is high specific fuel consumption. This paper solves the problem of improving the efficiency of this type of engine. The mathematical model of non-stationary processes of transfer of momentum, energy, mass, and the concentration of reacting substances in the estimated volume provides for the determination of local gas parameters in the entire computational region, which are presented as a sum of averaged and pulsation components. The k-ζ-f model is used as the turbulence model; the combustion is described by the coherent flame model (CFM) based on the concept of laminar flame propagation. As a result of the calculation, we obtained the values of temperature, pressure, and velocity of the working fluid in the working chamber cross-sections of a rotary–piston engine. Various options of the rotor recess shape are considered. Based on the data obtained, the rotor design was improved. The offered shape of the rotor recess has reduced emissions of both nitrogen oxides and carbon dioxide.

The Influence of Cr2O3 on the Sulfur Capture Efficiency of CaO in Pulverized Coal Combustion Process

2014 ◽  
Vol 997 ◽  
pp. 332-336
Author(s):  
Sheng Qin Zhang ◽  
Guang Jun Zhu ◽  
Neng Yun Deng ◽  
Yan Hong Gao
Keyword(s):  
Coal Combustion ◽  
Combustion Process ◽  
Pulverized Coal ◽  
Capture Efficiency ◽  
The Other ◽  
Pulverized Coal Combustion ◽  
Other Hand ◽  
The One ◽  
Sulfur Capture

The effects of Ca-based sulfur catcher on sulfur fixing were investigated by experiments. The results indicate that sulfur capture efficiency of CaO is the maximum when n(CaO)/n(S) ratio is equal to 2.5. Moreover, the influences of Cr2O3 on sulfur-fixing of CaO were studied when n(CaO)/n(S) ratio is equal to 2.5. The results indicate that addition of Cr2O3 can improve the sulfur capture efficiency of CaO, and efficiency of CaO is the best when Cr2O3 is added to 0.5%. This is because that Cr2O3 can be oxidized to CrO2. On the one hand, the oxides of chromium can catalyze the reaction of sulfur-fixing. On the other hand, CrO2 can react with SO2 to form Cr2(SO4)3. These also can improve the sulfur capture efficiency of Ca-based sulfur catchers.

Heat Exchanger Design Considerations for Gas Turbine HTGR Power Plant

1977 ◽  
Vol 99 (2) ◽  
pp. 237-245 ◽  
Author(s):  
C. F. McDonald ◽  
T. Van Hagan ◽  
K. Vepa
Keyword(s):  
Heat Exchanger ◽  
Power Plant ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Conversion ◽  
Structural Safety ◽  
Working Fluid ◽  
Closed Cycle ◽  
High Degree ◽  
Cycle Efficiency

The Gas Turbine High Temperature Gas Cooled Reactor (GT-HTGR) power plant combines the existing design HTGR core with a closed-cycle helium gas turbine power conversion system directly in the reactor primary circuit. Unlike open-cycle gas turbines where the recuperative heat exchanger is an optional component, the high cycle efficiency of the nuclear closed-cycle gas turbine is attributable to a high degree to the incorporation of the recuperator (helium-to-helium) and precooler (helium-to-water) exchangers in the power conversion loop. For the integrated plant configuration, a nonintercooled cycle with a high degree of heat recuperation was selected on the basis of performance and economic optimization studies. A recuperator of high effectiveness was chosen because it significantly reduces the optimum pressure ratio (for maximum cycle efficiency), and thus reduces the number of compressor and turbine stages for the low molecular weight, high specific heat, helium working fluid. Heat rejection from the primary system is effected by a helium-to-water precooler, which cools the gas to a low level prior to compression. The fact that the rejection heat is derived from the sensible rather than the latent heat of the cycle working fluid results in dissipation over a wide band of temperature, the high average rejection temperature being advantageous for either direct air cooling or for generation of power in a waste heat cycle. The high heat transfer rates in the recuperator (3100 MWt) and precooler (1895 MWt), combined with the envelope restraints associated with heat exchanger integration in the prestressed concrete reactor vessel, require the use of more compact surface geometries than in contemporary power plant steam generators. Various aspects of surface geometry, flow configuration, mechanical design, fabrication, and integration of the heat exchangers are discussed for a plant in the 1100 MWe class. The influence of cycle parameters on the relative sizes of the recuperator and precooler are also presented. While the preliminary designs included are not meant to represent final solutions, they do embody features that satisfy many of the performance, structural, safety, and economic requirements.

The Educational Project in the Context of High-Performance Sports

2020 ◽  
pp. 1-8
Author(s):  
Fabrice Burlot ◽  
Mathilde Desenfant ◽  
Helene Joncheray
Keyword(s):  
High Performance ◽  
The Other ◽  
Training Project ◽  
Educational Project ◽  
Other Hand ◽  
Social Balance ◽  
Adjustment Variable ◽  
The One ◽  
High Level

The requirements of performance sport are becoming more and more time-consuming for athletes. Based on the work of Rosa, the article looks into the ability of athletes to reconcile their training project and the increasing requirements of practice at a high level. To address this issue, we interviewed 63 high-level French athletes who train at the French Institute of Sport. The results show that although the training project appears to be time-consuming, it is nonetheless a source of social balance and a reassuring choice for their future professional retraining. In order to preserve this educational project in the time-consuming context of high-performance sports, athletes on the one hand implement strategies of arrangement in order to produce an acceptable timetable, and on the other hand use this temporality as an adjustment variable allowing them to better manage temporal emergencies. By giving athletes a voice, this work deconstructs the idea of the incompatibility of educational and sports projects and offers recommendations to sports institutions.

Finding the Semantic Relationship Between Wikipedia Articles Based on a Useful Entry Relationship

2020 ◽  
pp. 838-859
Author(s):  
Lin-Chih Chen
Keyword(s):  
High Performance ◽  
Semantic Analysis ◽  
Low Cost ◽  
Experimental Results ◽  
The Other ◽  
Semantic Relationship ◽  
Semantic Relationships ◽  
The One ◽  
Analysis Models ◽  
Cost Characteristics

Wikipedia is the largest online Internet encyclopedia, and everyone can create and edit different articles. On the one hand, because it contains huge amounts of articles and there are many different language versions, it often faces synonymous and polysemy problems. On the other hand, since some of the similar Wikipedia articles may have the same topic of discussion, it needs a suitable way to identify effectively the semantic relationships between articles. This paper first uses three well-known semantic analysis models LSA, PLSA, and LDA as evaluation benchmarks. Then, it uses the entry relationship between Wikipedia articles to design its model. According to the experimental results and analysis, its model has high performance and low cost characteristics compared with other models. The advantages of its model are as follows: (1) it is a good model for finding the semantic relationships between Wikipedia articles; (2) it is suitable for dealing with huge amounts of documentation.

scholarly journals FUNDING AND PERFORMANCE OF HIGH-LEVEL INDIVIDUAL SPORT IN BENIN

2020 ◽  
Vol 8 (11) ◽  
pp. 532-537
Author(s):  
Akouete Coffi David ◽  
◽  
Ahounouaïkpe Fifamin Judith ◽  
Hounsou Semako Julien ◽  
Dansou H. Pierre ◽  
...  
Keyword(s):  
High Performance ◽  
Public Funding ◽  
Research Work ◽  
The Other ◽  
Other Hand ◽  
And Performance ◽  
The One ◽  
High Level ◽  
Individual Sports

This research work entitled Financing of high performance individual sport in Benin aims to analyze on the one hand, the effects of insufficient funding of high performance athletes in Benin on the development of individual sport and support of their elites and, on the other hand, the type of funding that would be best suited to this situation in Benin. It focuses on three sources of funding for sport: public funding, self-funding and other sources of funding. The results of the study show that, on the one hand, the insufficiency of the budgets allocated to high-performance individual sports constitutes in part an obstacle to the development of this type of sport, and on the other hand, that public funding does not favor not the improvement of the performance of high performance individual athletes, compared to other sources of sport funding.

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