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Wyszukujesz frazę "Ziolkowski, P." wg kryterium: Autor


Wyświetlanie 1-9 z 9
Tytuł:
Analysis of possible application of high-temperature nuclear reactors to contemporary large-output steam power plants on ships
Autorzy:
Kowalczyk, T.
Głuch, J.
Ziółkowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/258948.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship power plants
steam turbines
nuclear reactors
PWR
HTR
variable operational conditions
Opis:
This paper is aimed at analysis of possible application of helium to cooling high-temperature nuclear reactor to be used for generating steam in contemporary ship steam-turbine power plants of a large output with taking into account in particular variable operational parameters. In the first part of the paper types of contemporary ship power plants are presented. Features of today applied PWR reactors and proposed HTR reactors are discussed. Next, issues of load variability of the ship nuclear power plants , features of the proposed thermal cycles and results of their thermodynamic calculations in variable operational conditions, are presented.
Źródło:
Polish Maritime Research; 2016, 2; 32-41
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergy analysis of the Szewalski cycle with a waste heat recovery system
Autorzy:
Kowalczyk, T.
Ziółkowski, P.
Badur, J.
Powiązania:
https://bibliotekanauki.pl/articles/240278.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Szewalski cycle
binary vapour cycle
exergy analysis
waste heat
idea Szewalskiego
analiza egzergii
ciepło odpadowe
Opis:
The conversion of a waste heat energy to electricity is now becoming one of the key points to improve the energy efficiency in a process engineering. However, large losses of a low-temperature thermal energy are also present in power engineering. One of such sources of waste heat in power plants are exhaust gases at the outlet of boilers. Through usage of a waste heat regeneration system it is possible to attain a heat rate of approximately 200 MWth, under about 90°C, for a supercritical power block of 900 MWel fuelled by a lignite. In the article, we propose to use the waste heat to improve thermal efficiency of the Szewalski binary vapour cycle. The Szewalski binary vapour cycle provides steam as the working fluid in a high temperature part of the cycle, while another fluid – organic working fluid – as the working substance substituting conventional steam over the temperature range represented by the low pressure steam expansion. In order to define in detail the efficiency of energy conversion at various stages of the proposed cycle the exergy analysis was performed. The steam cycle for reference conditions, the Szewalski binary vapour cycle as well as the Szewalski hierarchic vapour cycle cooperating with a system of waste heat recovery have been comprised.
Źródło:
Archives of Thermodynamics; 2015, 36, 3; 25-48
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hierarchical cycles in the modern power system – exergy analysis under partial loads
Autorzy:
Kowalczyk, T.
Ziółkowski, P.
Kornet, S.
Powiązania:
https://bibliotekanauki.pl/articles/175484.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hierarchical cycles
partial loads
combine cycles
Opis:
The aim of this paper is to investigate thermodynamic efficiency of hierarchical thermodynamic cycles under partial loads by using of exergy analysis. Advanced hierarchical cycles are composed of few energy conversion systems, which can be powered by several different sources of energy jointly. This kind of cooperation gives opportunities to provide high efficient and clean conversion of fossil fuels to electricity. Moreover, power plant consisting of few traditional power system gives new possibilities of optimization under partial loads.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2015, 129; 3-23
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhanced energy conversion as a result of fluid-solid interaction in micro- and nanoscale
Autorzy:
Badur, J.
Ziółkowski, P.
Kornet, S.
Kowalczyk, T.
Banaś, K.
Bryk, M.
Ziółkowski, P. J.
Stajnke, M.
Powiązania:
https://bibliotekanauki.pl/articles/281383.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
enhanced energy conversion
micro- and nanomechanics
fluid-solid interaction
pressure and thermally driven flow
Opis:
It is known that nano- and micromechanics require new approaches to right describing of surface-like phenomena which lead to an enhanced energy conversion. In this work, a general form of surface forces that consist of a contribution from both the friction and mobility components has been extended to collect the effects of bulk and surface motion of a fluid. Quite similar impact can be observed for a solid-fluid mixture, where the principle of effective stress for this new type of approach should be considered from the very beginning. The second motivation of our work is to present the multiscale domain of fluid-solid interaction which describes some “emergence effects” for materials with especially high volumetric surface densities.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 1; 329-332
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The problem of thermal unit elasticity under the conditions of dynamic RES development
Problem elastyczności bloków cieplnych w warunkach dynamicznego rozwoju OZE
Autorzy:
Kowalczyk, T.
Badur, J.
Ziółkowski, P.
Kornet, S.
Banaś, K.
Ziółkowski, P. J.
Stajnke, M.
Bryk, M.
Powiązania:
https://bibliotekanauki.pl/articles/397195.pdf
Data publikacji:
2017
Wydawca:
ENERGA
Tematy:
energy storage
operational flexibility
steam turbine
gas turbine
SOEC
hydrogen technologies
machine monitoring
magazyn energii
elastyczność pracy
turbina parowa
turbina gazowa
technologie wodorowe
monitoring maszyn
Opis:
The paper is an overview of selected ways of increasing the operational flexibility of steam units, which are predominant in the Polish power system. These studies were prompted by the dynamic changes in the structures of installed capacity and generation output in the National Power System due to a rapid increase in the number of wind turbines in the country. The methods of thermal unit operational flexibility improvement are divided into two groups. The first group comprises solutions with heat and mass storage as well as chemical energy storage. These are solutions to manage the auxiliary load of units regardless of system load. The second group consists of methods for an off-design increase in the safe level of thermal energy machine design stress. The development of numerical tools using complex methods of thermal stress determination, such as Burzyński-Pęcherski’s theory, combined with advanced on-line machine diagnostics, allows for an extension in the operational range of a machine, beyond the original safe operation limit without risk of damage or loss of service life, in other words.
W pracy przedstawiono przegląd wybranych sposobów zwiększania elastyczności pracy bloków parowych, które stanowią największą siłę wytwórczą w polskim systemie elektroenergetycznym. Motywacją do podjęcia prac w tym kierunku są dynamiczne zmiany w strukturze mocy zainstalowanej i energii wytwarzanej w Krajowym Systemie Elektroenergetycznym związane z szybkim wzrostem liczby siłowni wiatrowych na terenie kraju. Metody poprawy elastyczności pracy bloków cieplnych podzielono na dwie grupy. Pierwszą grupę stanowią rozwiązania wykorzystujące magazyny ciepła i masy oraz magazyny energii chemicznej. Są to rozwiązania pozwalające kształtować obciążenie potrzeb własnych bloku niezależnie od obciążenia systemu. Drugą grupę stanowią metody pozwalające na pozaprojektowe wytężanie konstrukcji maszyn cieplnych. Rozwój narzędzi numerycznych wykorzystujących złożone metody wyznaczania naprężeń cieplnych, takie jak np. teoria Burzyńskiego–Pęcherskiego, w połączeniu z zaawansowanymi systemami diagnostyki maszyn online, umożliwiają wychodzenie z pracą maszyn poza granice tzw. bezpiecznej pracy bez ryzyka uszkodzeń lub utraty żywotności.
Źródło:
Acta Energetica; 2017, 2; 116-121
2300-3022
Pojawia się w:
Acta Energetica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The thermodynamic analysis of the Szewalski hierarchic vapour cycle cooperating with a system of waste heat recovery
Autorzy:
Ziółkowski, P.
Kowalczyk, T.
Hernet, J.
Kornet, S.
Powiązania:
https://bibliotekanauki.pl/articles/175466.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
binary cycle
waste heat
ORC
thermodynamical analysis
numerical
analysis
CFM (computational flow mechanics)
Opis:
In this paper, thermodynamic analysis of the Szewalski hierarchic vapour cycle cooperating with a system of waste heat recovery from exhaust gases are presented. According to that purpose, the CFM (computation flow mechanics) approach has been used correctly. In this paper, traditional steam cycle, the bottoming organic Rankine cycle (ORC) and a system of waste heat recovery with use of water with temperature 90 ◦C have been analyzed. The Szewalski binary vapour cycle is providing steam as the working fluid in the high temperature part of the cycle, while another fluid – organic working fluid – as the working substance substituting conventional steam over the temperature range represented by the low pressure steam expansion. The steam cycle for reference conditions, the Szewalski binary vapour cycle, and the Szewalski hierarchic vapour cycle cooperating with a system of waste heat recovery have been comprised. Four working fluids in the low temperature part of binary cycle such as ammonia, propane, isobutene and ethanol have also been investigated. Moreover, the Szewalski cycle is a good resolution for proper using heat flux received from the exhaust gases heat regeneration system.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2015, 129; 51-75
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the effectiveness of the turbine condenser air extraction system using hydro ejectors
Autorzy:
Badur, J.
Kowalczyk, T.
Ziółkowski, P.
Tokarczyk, P.
Woźniak, M.
Powiązania:
https://bibliotekanauki.pl/articles/175162.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
condensation
steam condenser
Venturi nozzle
Dalton’s law
partial pressure
Opis:
The aim of the paper is to investigate the effectiveness of the 18K380 steam turbine condenser air extraction system using hydro ejectors. Motivation for the analysis was a need of improvement of the energy conversion ratio of the power plant. To achieve this goal it was necessary to establish efficiency of each subsystem of the energy cycle. The air extraction system is not a highly power consuming system but it has great impact on the steam cycle efficiency by influence on the condensation temperature. The air extraction system effectiveness depends on a weather conditions, exactly on the ambient temperature, which raises the question whether it is worth to modernize the hydro ejectors or replace them by a centrifugal vacuum pumps. To establish the vacuum system effectiveness a new innovative mass flow measuring system has been implemented to measure an air-steam mixture flow and the fraction of the air mass in the mixture. The measuring system is based on a Venturi nozzle supplemented with a temperature drop during the mixture expansion.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 131; 41-53
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of zero-dimensional model of SOFC with internal fuel reforming for complex hybrid energy cycles
Autorzy:
Badur, J.
Lemański, M.
Kowalczyk, T.
Ziółkowski, P.
Kornet, S.
Powiązania:
https://bibliotekanauki.pl/articles/184970.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fuel cell
SOFC
mathematical model
experiment
verification
ogniwo paliwowe
model matematyczny
eksperyment
weryfikacja
Opis:
The article presents a zero-dimensional mathematical model of a tubular fuel cell and its verification on four experiments. Despite the fact that fuel cells are still rarely used in commercial applications, their use has become increasingly more common. Computational Flow Mechanics codes allow to predict basic parameters of a cell such as current, voltage, combustion composition, exhaust temperature, etc. Precise models are particularly important for a complex energy system, where fuel cells cooperate with gas, gas-steam cycles or ORCs and their thermodynamic parameters affect those systems. The proposed model employs extended Nernst equation to determine the fuel cell voltage and steadystate shifting reaction equilibrium to calculate the exhaust composition. Additionally, the reaction of methane reforming and the electrochemical reaction of hydrogen and oxygen have been implemented into the model. The numerical simulation results were compared with available experiment results and the differences, with the exception of the Tomlin experiment, are below 5%. It has been proven that the increase in current density lowers the electrical efficiency of SOFCs, hence fuel cells typically work at low current density, with a corresponding efficiency of 45–50% and with a low emission level (zero emissions in case of hydrogen combustion).
Źródło:
Chemical and Process Engineering; 2018, 39, 1; 113--128
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A role of the heat and work uncompensated transformations in the balance of entropy and the turbomachinery efficienc
Autorzy:
Kowalczyk, T.
Ziółkowski, P.
Sławiński, D.
Cisak, M.
Badur, J.
Powiązania:
https://bibliotekanauki.pl/articles/175450.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
entropy balance
entropy sources
uncompensated transformations
isentropic efficiency
polytropic efficiency
eulerian fluid
turbine stage
Puzyrewski number
Opis:
The notion of heat uncompensated transformation has early been introduced by Clausius in 1854 and next, after fifty years of forgetting, in 1904 Duhem has revalorized it and combined it with a new notion of work uncompensated transformation [3]. In this way the so-called ClausiusDuhem inequality has been established. In our paper we wish to present a novelized procedure of estimating the role of the uncompensated transformations of heat and work within the flow of viscous and heat conducting working fluid like water stream. The original procedure was introduced by Puzyrewski and it is essential in expressing of a local, in time and space, balance of entropy. Futhermore, this unique approach leads to redefinition of the efficiency notion, as is usually applied to fluid-flow machineries, to a new one important in computational fluid dynamics (CFD) three-dimensional modeling. As a result, it is shown that usage of the polytropic efficiency, instead of the isentropic efficiency, is more convenient and seems to be natural in CFD approach. Helpfully, we have also found a correlation between those two efficiency definitions with usage of proposed new dimensionless (criterion) number.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2017, 135; 11-27
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

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