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


Wyświetlanie 1-10 z 10
Tytuł:
The analyzis of the stream-air mixture during a flow through a tube bank inside a condenser
Autorzy:
Krzyślak, P.
Joachimiak, M.
Powiązania:
https://bibliotekanauki.pl/articles/175261.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
condenser
pressure drop
steam-air mixture
water vapor condensation in a solution with air
partial pressure
Opis:
The paper presents the results of calculations related to the flow analysis of a tube bank taking into account the partial pressures of gases flowing through the condenser. Different mass share of the gas not condensing in the heat exchanger upstream to the first row of tubes and the partial pressures of water vapor and air have been taken into account. The value of the partial pressures of gases, pressures drop, temperature, velocity, Reynolds number, and air share in the subsequent rows of tubes have been calculated. This study is a basis for the analysis of heat exchange in the condenser considering the influence of the noncondensing gas. The increase in the share of air in the following rows of tubes results in an increase in the thermal resistance and condensation of increasingly lower mass of water vapor.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2014, 126; 131-140
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of the calculation process related to labyrinth sealing with extraction
Autorzy:
Joachimiak, D.
Joachimiak, M.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/955282.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
maszyna wirnikowa
maszyna przepływowa
uszczelnienie
labyrinth seals
turbomachines
fluid-flow machines
method of calculation labyrinth seals
Opis:
The work presents a calculation process enabling one-dimensional numerical calculations of labyrinth sealing. A DSV program determines the thermodynamic parameters of gas in the sealing chambers with extraction. The influence of the sealing length upon the stability of a matrix solution of the system of equations with the use of Cond(C) parameter is analysed. Next, the operation of the software extended with a module that enables determination of the initial pressure p0, to which the assumed mass flow for a set geometry and sealing length would correspond is discussed. The work analyzes Cond(C) and initial pressure values for various sealing lengths with an assumed leak value. The work also compares the values of static pressures on the extraction plane, as obtained from the measurements, to theoretically calculated values. The calculations and comparisons were made for various heights of incomplete sealing fissures.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 4; 1057-1066
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research and CFD calculations based investigations into gas flow in a short segment of a heavily worn straight through labyrinth seal
Autorzy:
Joachimiak, D.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/258744.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
labyrinth seals
turbomachines
fluid-flow machines
experiment
CFD
gas velocity
Opis:
Steam turbines are used as propulsion components in not only power plants but also on merchant and naval ships. The geometry of the steam turbine seals changes throughout the machine life cycle. The rate of deterioration of these seals, in turn, affects heavily the efficiency of the thermal machine. However, the literature overview does not provide any research reports on flow phenomena occurring in heavily deteriorated seals. The paper describes the course and results of investigations into a model straight through labyrinth seal composed of 4 discs, each with the slot height of 2 mm. The investigations have been conducted with air as the working medium. Changes of gas flow parameters due to wear were analysed. Based on the experimental data, more intensive leakage was observed as the result of the increased slot height. The static pressure distribution along the examined segment was measured. The experimentally recorded distribution differed remarkably from the theoretical assumptions. Another part of the experimental research focused on comparing the gas velocities at points situated upstream of the first and second seal disc. The velocity measurements were carried out using a constant temperature wire probe. This part of the investigations provided opportunities for analysing the influence of seal wear on gas flow conditions in the seal segment. The paper compares the results of the experimental research with those obtained using the CFX software. The presented results of velocity distributions provide a clear picture of the nature of the gas flow in the seal, which enables its analysis.
Źródło:
Polish Maritime Research; 2017, 2; 83-88
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of results of experimental research with numerical calculations of a model one-sided seal
Autorzy:
Joachimiak, D.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/239985.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
labyrinth seals
turbomachines
fluid-flow machines
uszczelnienia labiryntowe
maszyny wirnikowe
maszyny przepływowe
Opis:
Paper presents the results of experimental and numerical research of a model segment of a labyrinth seal for a different wear level. The analysis covers the extent of leakage and distribution of static pressure in the seal chambers and the planes upstream and downstream of the segment. The measurement data have been compared with the results of numerical calculations obtained using commercial software. Based on the flow conditions occurring in the area subjected to calculations, the size of the mesh defined by parameter y+ has been analyzed and the selection of the turbulence model has been described. The numerical calculations were based on the measurable thermodynamic parameters in the seal segments of steam turbines. The work contains a comparison of the mass flow and distribution of static pressure in the seal chambers obtained during the measurement and calculated numerically in a model segment of the seal of different level of wear.
Źródło:
Archives of Thermodynamics; 2015, 36, 2; 61-74
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparing N3-60 cascade exit angles obtained from tunnel measurements and numerical simulations
Autorzy:
Biernacki, R.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/259443.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
numerical calculations
profile characteristics
gas turbines
steam turbines
Opis:
The article compares the results of the measurements performed in the aerodynamic tunnel owned by the Czestochowa University of Technology and the numerical simulation done using the code FLUENT for a plane cascade of N3-60 profiles. The comparison study aims at assessing differences between the exit angles measured experimentally and those obtained from numerical calculations. Variable parameters in the measurements and the calculations were the relative pitch and the profile stagger angle. The measurements were performed in the flow of air. The same medium and having the same inlet parameters was assumed in the calculations. The calculations were performed in two dimensions for the compressible flow. The k-ĺ RNG turbulence model was used to complete the equation system. Comparing the measured and calculated results provides opportunities for assessing the range of differences between the experiment and the simulation. The obtained results and formulated conclusions will find the application not only in the power industry, but also in the shipbuilding industry for analysing the operation of steam and gas turbines used as main and auxiliary propulsion systems on both merchant vessels and battle ships.
Źródło:
Polish Maritime Research; 2010, 1; 51-56
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of energy potential of three ways of configuration of a condenser power plant thermal cycle
Autorzy:
Chmielniak, T.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/258540.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Comparative analysis of energy
condenser
power plant
thermal cycle
new regeneration
separation preheater
Opis:
A theoretical, comparative analysis of three configuration ways of a condenser power plant thermal cycle is shown in the work. A new regeneration & separation preheater and its application in a thermal cycle is presented. Results obtained allow to compare all three analysed configurations efficiencies.
Źródło:
Polish Maritime Research; 2008, 4; 30-36
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculations of labyrinth seals with and without diagnostic extraction in fluid-flow machines
Autorzy:
Kaszowski, P.
Dzida, M.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/259462.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
labyrinth seals
Fanno curve
diagnostic extraction
Opis:
Labyrinth seals are essential components of steam turbine unit constructions. Two types of labyrinth seals can be named, the first of which is the seal without diagnostic steam extraction, and the second – with extraction. The distribution of flow parameters along the packing is affected remarkably by the average seal clearance. The presence of diagnostic extraction leads to the equation system which is determinable and can be inversed to calculate the average seal clearance Si. Analysing the obtained results leads to the conclusion that the information about this parameter provides opportunities to monitor the current state of the packing in real time. The applied calculation procedure bases on the de Saint - Venant equation. The article also includes a brief description of both types of seals.
Źródło:
Polish Maritime Research; 2013, 4; 34-38
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of heat flow in a tube bank of a condenser considering the influence of air
Autorzy:
Joachimiak, M.
Joachimiak, D.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/240202.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
condensation
inert gas
mass share of gas noncondensing in water vapor
Dalton’s law
water vapor pressure
air partial pressure
kondensacja
gaz obojętny
Prawo Daltona
ciśnienie pary wodnej
ciśnienie parcjalne
Opis:
The pressure of wet water vapor inside a condenser has a great impact on the efficiency of thermal cycle. The value of this pressure depends on the mass share of inert gases (air). The knowledge of the spots where the air accumulates allows its effective extraction from the condenser, thus improving the conditions of condensation. The condensation of water vapor with the share of inert gas in a model tube bank of a condenser has been analyzed in this paper. The models include a static pressure loss of the water vapor/air mixture and the resultant changes in the water vapor parameters. The mass share of air in water vapor was calculated using the Dalton’s law. The model includes changes of flow and thermodynamic parameters based on the partial pressure of water vapor utilizing programmed water vapor tables. In the description of the conditions of condensation the Nusselts theory was applied. The model allows for a deterioration of the heat flow conditions resulting from the presence of air. The paper contains calculations of the water vapor flow with the initial mass share of air in the range 0.2 to 1%. The results of calculations clearly show a great impact of the share of air on the flow conditions and the deterioration of the conditions of condensation. The data obtained through the model for a given air/water vapor mixture velocity upstream of the tube bank allow for identification of the spots where the air accumulates.
Źródło:
Archives of Thermodynamics; 2017, 38, 3; 119-134
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model of gas flow with friction in a slotted seal
Autorzy:
Joachimiak, D.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/239930.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
slotted seals
annular slot
friction coefficient
gas flow
uszczelki szczelinowe
szczelina pierścieniowa
współczynnik tarcia
przepływ gazu
Opis:
The paper discusses thermodynamic phenomena accompanying the flow of gas in a slotted seal. The analysis of the gas flow has been described based on an irreversible adiabatic transformation. A model based on the equation of total enthalpy balance has been proposed. The iterative process of the model aims at obtaining such a gas temperature distribution that will fulfill the continuity equation. The model allows for dissipation of the kinetic energy into friction heat by making use of the Blasius equation to determine the friction coefficient. Within the works, experimental research has been performed of the gas flow in a slotted seal of slot height 2 mm. Based on the experimental data, the equation of local friction coefficient was modified with a correction parameter. This parameter was described with the function of pressure ratio to obtain a mass flow of the value from the experiment. The reason for taking up of this problem is the absence of high accuracy models for calculating the gas flow in slotted seals. The proposed model allows an accurate determination of the mass flow in a slotted seal based on the geometry and gas initial and final parameters.
Źródło:
Archives of Thermodynamics; 2016, 37, 3; 95-108
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method of diagnosing labyrinth seals in fluid-flow machines
Autorzy:
Krzyślak, P.
Winowiecki, M.
Powiązania:
https://bibliotekanauki.pl/articles/259824.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
labyrinth sealings
steam turbines
sealing diagnostics
Opis:
Steam turbines constitute fluid flow machines which are used for driving engines of power plants, merchant and naval ships. They are commonly applied in power industry to driving electric generators. One of the impotant elements which affect efficiency of steam turbines used in power industry and for ship propulsion is state of labyrinth sealings whose aim is to minimize losses associated with steam leakage within turbine casing. Until now to assess state of labyrinth sealings has been only possible after stopping the turbine and its dismantling in order to determine values of clearances in the sealings. This paper presents a method which makes it possible to assess state of labyrinth sealings without the necessity of stopping and dismantling the machine. This is the method which allows to assess on-line state of machine sealings during its operation.
Źródło:
Polish Maritime Research; 2008, 3; 38-41
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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