Temat: lifetime - Katalog OPAC zbiorów

Skocz do pozycji: 106.

Tytuł:: Concept of advanced lifetime monitoring system for steam turbines
Koncepcja zaawansowanego systemu monitorowania żywotności turbin parowych
Autorzy:: Banaszkiewicz, Mariusz
Powiązania:: https://bibliotekanauki.pl/articles/1840894.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:: monitoring
steam turbines
lifetime assessment
low-cycle fatigue
creep
monitorowanie
turbina parowa
ocena żywotności
zmęczenie małocyklowe
pełzanie
Opis:: The increasing share of renewables in electricity production adversly affects the operation of thermal plants, including steam turbine units. Intermittency of renewable sources results in high variability of steam turbine operating conditions, which together with the inherent scatter of turbine operating parameters significantly complicates their lifetime assessment. The paper presents a concept of lifetime monitoring system in scope of creep-fatigue damage. The system is based on online and offline calculations, performs online analysis of measurement data and takes into account the results of material tests. Functionality of the system main modules is described and mathematical models suitable for online calculations are presented. A general concept of hardware configuration for the system is proposed as well.
Wzrastający udział odnawialnych źródeł energii w produkcji prądu ma niekorzystny wpływ na pracę elektrowni cieplnych, w tym bloków parowych. Niestabilność źródeł odnawialnych skutkuje dużą zmiennością warunków pracy turbin parowych, co w połączeniu z nieodłącznym rozrzutem parametrów pracy turbin w znaczący sposób komplikuje ocenę ich żywotności. W artykule przedstawiono koncepcję systemu monitorowania żywotności w zakresie zużycia zmęczeniowo-pełzaniowego. System ten oparty jest na obliczeniach w trybie online i offline, wykonuje na bieżąco analizę danych pomiarowych oraz uwzględnia wyniki badań materiałowych. Omówione zostały funkcje głównych modułów systemu wraz z propozycją modeli matematycznych odpowiednich do obliczeń w trybie online. Zaproponowano również ogólną koncepcję konfiguracji sprzętowej systemu.
Źródło:: Diagnostyka; 2021, 22, 1; 23-29
1641-6414
2449-5220
Pojawia się w:: Diagnostyka
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 107.

Tytuł:: Advanced lifetime assessment of steam turbine components based on long-term operating data
Autorzy:: Banaszkiewicz, M.
Radulski, W.
Dominiczak, K.
Powiązania:: https://bibliotekanauki.pl/articles/139746.pdf
Data publikacji:: 2018
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: steam turbine
lifetime assessment
creep
low cycle fatigue
turbina parowa
szacowanie cyklu życia
pełzanie
zmęczenie niskocyklowe
Opis:: The paper presents a new method of lifetime calculations of steam turbine components operating at high temperatures. Component life is assessed on the basis of creep-fatigue damage calculated using long-term operating data covering the whole operating period instead of representative events only. The data are analysed automatically by a dedicated computer program developed to handle big amount of process data. Lifetime calculations are based on temperature and stress analyses performed by means of finite element method and using automatically generated input files with thermal and mechanical boundary conditions. The advanced lifetime assessment method is illustrated by an example of lifetime calculations of a steam turbine rotor.
Źródło:: Archive of Mechanical Engineering; 2018, LXV, 4; 579-597
0004-0738
Pojawia się w:: Archive of Mechanical Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 108.

Tytuł:: Numerical investigation of creep behaviour of high-temperature steam turbine compone
Autorzy:: Banaszkiewicz, M.
Powiązania:: https://bibliotekanauki.pl/articles/175375.pdf
Data publikacji:: 2012
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: creep
lifetime assessment
steam turbine
Opis:: The paper presents a model for creep basing on the so-called characteristic creep strain. It illustrates its application in computations of old steam turbines components. The presented model is a modification of the Norton model which relates the stress exponent to the creep rupture strength and current stress. Creep strain is a function of the above two quantities, i.e., rupture strength and current stress, and acharacteristic creep strain which is material constant for a given time and temperature. Computational examples regard the rotating and pressure components analysed using the finite element method.
Źródło:: Transactions of the Institute of Fluid-Flow Machinery; 2012, 124; 5-15
0079-3205
Pojawia się w:: Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 109.

Tytuł:: A method for estimating the probability distribution of the lifetime for new technical equipment based on expert judgement
Autorzy:: Andrzejczak, Karol
Bukowski, Lech
Powiązania:: https://bibliotekanauki.pl/articles/2038033.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:: uncertainty
expert elicitation of lifetime
quantile function
Weibull distribution
Opis:: Managing the exploitation of technical equipment under conditions of uncertainty requires the use of probabilistic prediction models in the form of probability distributions of the lifetime of these objects. The parameters of these distributions are estimated with the use of statistical methods based on historical data about actual realizations of the lifetime of examined objects. However, when completely new solutions are introduced into service, such data are not available and the only possible method for the initial assessment of the expected lifetime of technical objects is expert methods. The aim of the study is to present a method for estimating the probability distribution of the lifetime for new technical facilities based on expert assessments of three parameters characterizing the expected lifetime of these objects. The method is based on a subjective Bayesian approach to the problem of randomness and integrated with models of classical probability theory. Due to its wide application in the field of maintenance of machinery and technical equipment, a Weibull model is proposed, and its possible practical applications are shown. A new method of expert elicitation of probabilities for any continuous random variable is developed. A general procedure for the application of this method is proposed and the individual steps of its implementation are discussed, as well as the mathematical models necessary for the estimation of the parameters of the probability distribution are presented. A practical example of the application of the developed method on specific numerical values is also presented.
Źródło:: Eksploatacja i Niezawodność; 2021, 23, 4; 757-769
1507-2711
Pojawia się w:: Eksploatacja i Niezawodność
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 110.

Tytuł:: Improvement of enzyme stability via non-covalent complex formation with dextran against temperature and storage lifetime
Autorzy:: Altikatoglu, M.
Kuzu, H.
Powiązania:: https://bibliotekanauki.pl/articles/778394.pdf
Data publikacji:: 2010
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:: stabilizacja termiczna
enzymy
dekstran
thermal stabilization
complex
enzyme
dextran
storage lifetime
Opis:: The optimal methodology to prepare the novel modified enzyme, polymer-enzyme complex, was developed to give a high catalytic activity in aqueous solution. The non-covalent complexes of two different enzymes (horseradish peroxidase and glucose oxidase) were prepared with various molar ratios (nD/nE 0,05; 0,1; 1; 5; 10; 15; 20) by using 75kDa dextran. The thermal stabilities of the obtained complexes were evaluated with the activities determined at different temperatures (25, 30, 35, 40, 50, 60, 70, 80°C) applying 60 minutes incubation time for pH 7. The complexes with the molar ratio nD/nHRP: 10 and nD/nGOD: 5 showed the highest thermal stability. Its activity was very high (ca. 1,5-fold higher activity than pure enzyme for HRP-dextran complexes) and almost the same between applying one hour incubation time and without incubation, and could also be measured at high temperatures (70, 80 °C). We finally succeeded in preparing dextran-enzyme complexes which showed higher activity than pure enzyme in aqueos solution at all temperatures for pH 7. In addition, the mentioned complexes at pH 7 had very long storage lifetime compared to purified enzyme at +4 °C; which is considered as a good feature for the usage in practice.
Źródło:: Polish Journal of Chemical Technology; 2010, 12, 1; 12-16
1509-8117
1899-4741
Pojawia się w:: Polish Journal of Chemical Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 111.

Tytuł:: Kompetencje relacyjne młodych dorosłych nieposiadających i posiadających partnera życiowego
Autorzy:: Adamczyk, Katarzyna
Powiązania:: https://bibliotekanauki.pl/articles/637382.pdf
Data publikacji:: 2012
Wydawca:: Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:: lifetime partner
partnered life
relational competences
single life
young adulthood
Opis:: The review of literature and studies let us suppose that a definite level of relational competences create greater or less possibilities to find a lifetime partner, and to maintain a relationship with him or her. In the article the findings of the research with 457 young single and partnered adults are presented. Their aim was to verify whether are there any differences between young single and partnered adults in the extent of level of relational competences, which indices were five six bonding behaviours (behaviours of psychic and physical closeness, impressive behaviours, behaviours on the behalf of a partner and a relationship, conciliatory behaviours, and sexual behaviours). Additionaly an association between level of relational competences and gender was analysed. It was assumed that lower level of competences will be characteristic of single adults. Moreover, it was hypothesized that females will possess a higher level of competences in comparison to males. Statistical analysis showed that the observed difference between single and partnered groups in the area of relational competences is statistically significant. Single individuals reveal a lower level of relational competences in the realm of the above-mentioned bonding behaviours. At the same time, gender showed to be a differentiating factor only in the area of competences concerned behaviours of psychic and physical closeness, and sexual behaviours.
Źródło:: Psychologia Rozwojowa; 2012, 17, 2; 87-100
1895-6297
2084-3879
Pojawia się w:: Psychologia Rozwojowa
Dostawca treści:: Biblioteka Nauki

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