Wyniki wyszukiwania dla: STEAM
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Structural and electrical transport properties of Pr-doped SrTi0.93Co0.07O3-δ a novel SOEC fuel electrode materials
PublikacjaSolid Oxide Electrolyzer Cells (SOECs) are very promising electrochemical devices for the production of syngas (H2/CO) by H2O and CO2 co-electrolysis. The structure, microstructure and electrical properties of the fuel electrode material play a crucial role in the performance of the whole cell and efficiency of electrocatalytic reduction of steam into hydrogen. In the present work, a novel Co and Pr co-doped SrTiO3-δ material attracted...
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The Morphology, Structure, Mechanical Properties and Biocompatibility of Nanotubular Titania Coatings before and after Autoclaving Process
PublikacjaThe autoclaving process is one of the sterilization procedures of implantable devices. Therefore, it is important to assess the impact of hot steam at high pressure on the morphology, structure, and properties of implants modified by nanocomposite coatings. In our works, we focused on studies on amorphous titania nanotubes produced by titanium alloy (Ti6Al4V) electrochemical oxidation in the potential range 5–60 V. Half of the...
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Programowo-sprzętowa platforma symulacyjna - Hardware In the Loop - zaawansowanego układu sterowania poziomem wody w pionowej wytwornicy pary elektrowni jądrowej
PublikacjaW artykule przedstawiono koncepcję programowo-sprzętowej platformy symulacyjnej wykorzystującej technikę symulacji w pętli sprzętowej HIL (ang. Hardware In The Loop simulation), wykorzystanej dla potrzeb projektowania i weryfikacji w czasie rzeczywistym (ang. Real Time) zaawansowanych algorytmów sterowania poziomem wody w pionowej wytwornicy pary elektrowni jądrowej. Jej głównymi elementami są: środowisko czasu rzeczywistego Matlab/Simulink...
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Programowo-sprzętowa platforma symulacyjna - Hardware In the Loop - zaawansowanego układu sterowania poziomem wody w pionowej wytwornicy pary elektrowni jądrowej
PublikacjaW artykule przedstawiono koncepcję programowo-sprzętowej platformy symulacyjnej wykorzystującej technikę symulacji w pętli sprzętowej HIL (ang. Hardware In The Loop simulation), wykorzystanej dla potrzeb projektowania i weryfikacji w czasie rzeczywistym (ang. Real Time) zaawansowanych algorytmów sterowania poziomem wody w pionowej wytwornicy pary elektrowni jądrowej. Jej głównymi elementami sa: środowisko czasu rzeczywistego Matlab/Simulink...
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Extremal thermal loading of a bifurcation pipe
PublikacjaThe subject of considerations is a spherical bifurcation pipe of a live steam made of steel P91, which is an element of a block of coal-fired power plant working with a 18K370 turbine. As experience shows, it is a very sensitive element of the boiler pipelines. An extreme work scenario for such a block has been adopted, in which the turbine is shutting down to a warm state three times in 24 hours. This is an action dictated by...
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HIERARCHICAL CYCLES IN MODERN POWER SYSTEMS – EXERGY ANALYSIS UNDER PART LOADS
PublikacjaThe aim of the paper is to investigate thermodynamic efficiency of advanced hierarchic power cyclesunder partial loads by using of exergy analyze. Advanced hierarchical power systems arecomposed of few energy conversion cycles, most common are steam and gas cycles in various configurations, but they may contain fuel cells, ORC, lithium bromide absorption chillers and others. Moreover hierarchical cycles can be powered by several...
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Numerical simulation of temperature distribution of heat flow on reservoir tanks connected in a series
PublikacjaThe flow of temperature distribution through a medium in thermodynamic studies plays an important role in understanding physical phenomena in chemical science and petroleum engineering, while temperature distribution indicates the degree of reaction that must be undergone to obtain the final product. Therefore, this paper aims to present and apply the exponential matrix algorithm (EMA), differential transformation algorithm (DTA),...
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Modeling by finite element methods of impact of erosion on frequency of normal modes of L-0 blade
PublikacjaAfter some time of exploitation steam turbine rotors blades in energetic industry they are being eroded and also their frequency of normal modes is changed. Those changes can cause to unwanted shift of blades normal mode frequencies. It is necessary to find quick method of rating changes of frequency in connection of mass loss due erosion. The evaluation of this dependence was made by finite element modeling method using HyperWorks...
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Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion
PublikacjaThe efffciencies of the Organic Rankine Cycle (ORC) are not very high and only very seldom do they exceed 20%. The increase and optimization of initial parameters and certain modifications of the thermodynamic cycle make it possible to overcome these drawbacks. A new modified cycle has been described and analyzed in detail in the paper. Similarly to the Ericsson cycle for gas turbines, isothermal expansion in the turbine is suggested...
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Thermodynamic and economic analysis of nuclear power unit operating in partial cogeneration mode to produce electricity and district heat
PublikacjaThis paper presents the methodology of techno-economic analysis for a nuclear unit operating in partial cogeneration mode and its application for the case study: a nuclear power plant planned in Poland. The research objectives were: to propose EPR, AP1000 and ESBWR nuclear condensing-extraction turbine systems modifications required for operation in cogeneration, to determine optimal heat production and heat transport line (HTL)...
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Chlorine-free extraction and structural characterization of cellulose nanofibers from waste husk of millet (Pennisetum glaucum)
PublikacjaThis study aims to extract cellulose nanofibers (CNFs) from a sustainable source, i.e. millet husk, which is an agro-waste worthy of consideration. Pre-treatments such as mercerisation, steam explosion, and peroxide bleaching (chlorine-free) were applied for the removal of non-cellulosic components. The bleached millet husk pulp was subjected to acid hydrolysis (5% oxalic acid) followed by homogenization to extract CNFs. The extracted...
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On the internal efficiency of a turbine stage: classical and CFD definitions
PublikacjaAlmost entire fleet of steam turbines in Poland was designed between 1950 – 1980 with the use of the so-called zero dimensional (0D) calculation tools. For several years, design and modernization of the turbines occur in assistance with the state of the art methods that describe working fluid flow field based on 3D models and CFD codes. This cooperation between 0D and 3D codes requires exchange of overall, integral information...
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Investigations of Energy Conversion and Surface Effect for Laser-Illuminated Gold Nanorod Platforms
PublikacjaAchieving a quick temperature increase is a burning issue for biophysical applications, like germ inactivation and tumor ablation, and for energy performances, like solar collectors and steam generators. Based on the plasmon resonance phenomenon, noble metallic nanoparticles have emerged as promising weapons due to their very high biocompatibility, optical properties, and high surface-to-volume ratio, increasing energy conversion...
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Biowodór, „paliwo przyszłości”, dotychczasowe metody otrzymywania , porównanie metod otrzymywania
PublikacjaWodór jest ważnym pierwiastkiem w przemyśle chemicznym. Biowodór wydaje się być użytecznym odnawialnym nośnikiem energii, który mógłby zastąpić paliwa kopalne. Największym problemem wodoru jest jego rzadkie występowanie w czystej formie molekularnej H 2 . Dlatego otrzymanie biowodoru w objętościach opłacalnych ja ko surowiec czy biopaliwo wiedzie przez bioodpady „przesycone” wodorem. Każdy związek...
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IN VITRO PROPAGATION OF RHODODENDRON TOMENTOSUM - AN ENDANGERED ESSENTIAL OIL BEARING PLANT FROM PEATLAND
PublikacjaRhododendron tomentosum Harmaja (formerly Ledum palustre L.) is a medicinal peat bog plant native to northern Europe, Asia and North America. This plant has a distinctive aroma thanks to the presence of essential oil, to which it also owes its anti-inflammatory, analgesic, antimicrobial and insecticidal properties. However, in Europe R. tomentosum is classified as an endangered species, mainly due to degradation of peatlands. In...
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Advanced Turbine Cycles with Organic Media
PublikacjaOrganic Rankine Cycle (ORC) power plants have become very popular and have found their applications in systems with renewable sources of energy. So far their overall efficiencies are not very impressive and only for the upper temperature of about 300 °C do they exceed 20%. A drawback of these cycles is the limitation of the cycle upper temperature due to the heat exchanger technology and the materials used. However, it is possible...
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Organic Supercritical Thermodynamic Cycles with Isothermal Turbine
PublikacjaOrganic Rankine cycles (ORC) are quite popular, but the overall efficiencies of these plants are rather very low. Numerous studies have been conducted in many scientific centers and research centers to improve the efficiency of such cycles. The research concerns both the modification of the cycle and the increase in the parameters of the medium at the inlet to the turbine. However, the efficiency of even these modified cycles rarely...
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Fault detection in measuring systems of power plants
PublikacjaThis paper describes possibility of forming diagnostic relations based on application of the artifical neural networks (ANNs), intended for the identifying of degradation of measuring instruments used in developed power systems. As an example a steam turbine high-power plant was used. And, simulative calculations were applied to forming diagnostic neural relations. Both degradation of the measuring instruments and simultaneously...
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Jan Wajs dr hab. inż.
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Mathematical modeling and prediction of pit to crack transition under cyclic thermal load using artificial neural network
PublikacjaThe formation of pitting is a major problem in most metals, which is caused by extremely localized corrosion that creates small holes in metal and subsequently, it changes into cracks under mechanical load, thermo-mechanical stress, and corrosion process factors. This research aims to study pit to crack transition phenomenon of steel boiler heat tubes under cyclic thermal load, and mathematical modeling...
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Complex multidisciplinary optimization of turbine blading systems
PublikacjaThe paper describes the methods and results of direct optimization of turbine blading systems using a software package Opti_turb. The final shape of the blading is obtained from minimizing the objective function, which is the total energy loss of the stage, including the leaving energy. The current values of the objective function are found from 3D RANS computations (from a code FlowER) of geometries changed during the process...
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A novel concept of negative CO2 emission power plant for utilization of sewage sludge
PublikacjaCarbon Capture and Storage (CSS) technology is considered an important “bridge technology”, allowing effective abatement of CO2 emissions for power units using fossil fuels. However, if biomass is used in a power plant, equipped with CCS system, negative CO2 emissions can be achieved. In practice, wide development of such technologies would enable not only reduction of CO2 emissions, but also reversal of the harm done so far. In...
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Double-stage ORC system based on various temperature waste heat sources of the negative CO2 power plant
PublikacjaAnalysed is the modification of the thermodynamic cycle with the negative CO2 power plant concept by its combination with the organic Rankine cycle. The analysed power plant operates on a gas produced from the gasification of sewage sludge. The negative emission term comes from the aggregated CO2 balance resulting from the capture of the CO2, while the sewage sludge is one of the inevitable environmental sources of CO2 to be avoided....
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Cathodic Activation of Titania-Fly Ash Cenospheres for Efficient Electrochemical Hydrogen Production: A Proposed Solution to Treat Fly Ash Waste
PublikacjaFly ash (FA) is a waste product generated in huge amounts by coal-fired electric and steam-generating plants. As a result, the use of FA alone or in conjunction with other materials is an intriguing study topic worth exploring. Herein, we used FA waste in conjunction with titanium oxide (TiO2) to create (FA-TiO2) nanocomposites. For the first time, a cathodic polarization pre-treatment regime was applied to such nanocomposites...