Results 1 - 10 of 1233
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[en] The scope of this study was to determine the concentration and composition of atmospheric particulate matter of aerodynamic diameter < 10 μm (PM10) in the vicinity of coal-fired Ropar thermal power plant near Chandigarh, India. Two sampling sites, on inside the thermal plant and the other, outside the thermal plant were chosen. The elemental analysis was done using Proton Induced X-ray Emission (PIXE) technique. The elements detected at both the sites were common i.e. Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu and Zn however, their concentration vary at both the sampling sites. Also, Principal Component (PC) and Enrichment Factor (EF) analysis were done in order to identify the contributing elemental sources towards the particulate matter. Contributing sources to the elements were found not only the emission from the coal-fired thermal power plant but also from other activities like vehicular emissions, household cooking and natural soil dust etc. (author)
[en] Whenever the share of electro-nuclear generation in an electric power system is increased the work in the load following mode becomes more important. Failure of nuclear power stations to adapt with changes in the load, and with changes in the rotational reserve of the system, will cause constrains on the share of the system obtained from electro-nuclear generation. This paper presents a study of some aspects relevant to power system containing one or more of electro-nuclear stations, which is built around pressurized water reactors, and to operate the stations in the load following mode. The paper also covers the technical and economical effects of bringing the fuel life cycle closer to its end on the properties of the load following for the station. (author)
[en] The position of pellet fuel particles in a burner largely determines their combustion behaviour. This paper addresses the simulated motion of circles and spheres, equivalent to pellet, and their final position in a packed bed subject to a gravitational field confined inside rigid cylindrical walls. A simplified Monte Carlo statistical technique has been described and applied with the standard Metropolis method for the simulation of movement. This simplification provides an easier understanding of the method when applied to solid fuels in granular form, provided that they are only under gravitational forces. Not only have we contrasted one parameter, as other authors, but three, which are radial, bulk and local porosities, via Voronoi tessellation. Our simulations reveal a structural order near the walls, which declines towards the centre of the container, and no pattern was found in local porosity via Voronoi. Results with this simplified method are in agreement with more complex previously published studies.
[en] Gas turbines are widely used for power generation. In cogeneration system, the gas turbine generates electricity and the exhaust heat from the gas turbine is used to generate steam or chilled water. Besides enhancing the efficiency of the system, the process assists in reducing the emission of CO_2 to the environment. This study analyzes the amount of CO_2 emission by Universiti Teknologi Petronas gas fuelled cogeneration system using energy balance equations. The results indicate that the cogeneration system reduces the CO_2 emission to the environment by 60%. This finding could encourage the power plant owners to install heat recovery systems to their respective plants
[en] Issues on the electropower system development in Armenia are analysed. The basic prerequisites of the long-term development of the RA power sector are revealed in the context of regional integration. Ways of solving the considered problems are proposed
Research and development of methods and technologies for CO2 capture in fossil fuel power plants and storage in geological formations in the Czech Republic, stage E2: Methods of and technologies for CO2 capture from flue gas and a draft conceptual design of 2 selected variants of a CO2 capture system for a Czech coal fired power plant unit. Final report for Stage 2. Revision 0
[en] The following topics are summarised: Aim and scope of Stage 2. List of research reports developed within Stage 2. Stage 2.1: Methods of and technologies for post-combustion CO2 capture from the flue gas. Status of research and development worldwide. Stage 2.2: Oxyfuel method and technology. Status of research and development worldwide. Stage 2.3: Selection of a chemical absorption based method for post-combustion CO2 separation; and Stage 2.4: Conceptual proposals for a technological solution for the selected chemical absorption based method and for application of the oxyfuel method. (P.A.)
[en] Highlights: • The principles of power plant efficiency increase by coal pre-drying were revealed. • Formulation of impacts of coal pre-drying on units and plants’ performance. • Large energy amount of dried coal contribute the largest to the efficiency increase. • Larger initial moisture content induces greater power plant efficiency increase. - Abstract: A theoretical investigation of the principles of energy efficiency improvement in coal-fired power plants by removing a portion of the coal moisture content was performed. The relationship between the degree of pre-drying and coal’s energy flow rate, boiler efficiency and power auxiliary rate were comprehensively formulized and graphically presented. The performance of the coal pre-drying power plants using coals with different initial moisture content was also discussed. The results showed that, coal’s energy flow rate would increase by 0.6–1.5% as 0.1 kg moisture was removed per kg raw coal. The boiler efficiency would increase by 0.4–0.5% and the power auxiliary rate would slightly decrease by ∼0.2%. Eventually, the net efficiency of the power plant could increase in the range of 0.6–0.9%. Economic evaluation showed that the power plant performed more economically compared with the plant without coal pre-drying. This work provides a broadly applicable approach to formulaically revealing the principles of energy efficiency improvement in power plants by coal pre-drying.
[en] Highlights: • Thermodynamic analysis of thermal power plants with pressure gain combustion. • Time-resolved numerical model of rotating detonation combustor. • Method of characteristic model of supersonic turbines. • Guidance to select range of operation of gas turbines with pressure gain combustion. • Gas turbine design trade-off between deflagration and detonation combustors. - Abstract: A rotating detonation combustor is a form of “pressure gain combustion” where one or more detonations continuously travel around an annular channel. Pressure gain combustion is a prospective technology being explored to advance gas turbine power plants. These thermodynamic cycles could potentially deliver a performance increase of 20% beyond the current state of the art. However, the combustor operates at extremely unsteady harsh conditions, and the integration of the combustor with the turbomachinery represent unprecedented aero-thermo-structural challenges. At a given instant each stream line experiences a different compression process through the combustor. In contrast to conventional combustors, where a steady approach is valid, in rotating detonation engines the flow particles entering the compressor will be exposed to different processes depending on the relative position of the rotor shaft to the detonation front. Hence, the overall performance assessment requires the development of ad-hoc tools suitable for this new class of combustors, and the modeling of the turbine exposed to supersonic pulsating flows. This paper presents a numerical tool to evaluate precisely the thermodynamic and non-isentropic processes across the entire engine. The NASA’s Toolbox for the Modeling and Analysis of Thermodynamic Systems was used to implement new libraries to help us quantify the benefits of a rotating detonation engine versus the conventional technology equipped with constant pressure combustion. The new developed libraries, based on sets of physics-based principles, replicate the engine components performance. This model should allow the optimization of components with respect to energy availability to enable optimal engine sizing and operation. Finally, the paper presents the pressure ratios for which the rotating detonation based engine outperforms the conventional power plants based on the Brayton cycle.