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Wyświetlanie 1-4 z 4
Tytuł:
A new method for optimum heating of pressure components in supercritical steam power blocks
Autorzy:
Rząsa, D.
Duda, P.
Powiązania:
https://bibliotekanauki.pl/articles/240145.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
kotły parowe
metody optymalizacji
wymiana ciepła
heat transfer
optimization methods
steam boilers
total stresses
Opis:
One of the major concerns of the power energy industries is a proper operation of steam power blocks. Pressurized working medium and high temperature cause very high stresses in the construction elements such as collectors, separators or steam valves. They are exposed to sudden temperature and pressure changes that cause high stresses at certain points. Additionally, the cyclic character of loading causes material fatigue, known as low-cyclic fatigue, which may lead to the formation of fracture. Thus, methodologies offered by many companies should ensure reliable and safe operation of steam power blocks. The advanced numerical solutions for determining time-optimum medium temperature changes are presented. They are based on Levenberg-Marquardt and nonlinear programming by quadratic Lagrangian methods. The methods allow us to find parameters for start-up and shut-down operation that can reduce total stresses to limits governed by European regulations. Furthermore, the heating and cooling operations are conducted in a shortest time possible.
Źródło:
Archives of Thermodynamics; 2012, 33, 3; 133-145
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical method for determining the allowable medium temperature during transient operation of a thick-walled boiler element in power plant
Autorzy:
Rząsa, D.
Duda, P.
Powiązania:
https://bibliotekanauki.pl/articles/240222.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
elektrownia
naprężenie cieplne
optymalizacja
wymiana ciepła
heat transfer
optimization
power plant
thermal stresses
Opis:
Secure and cost-effective power generation has become very important nowdays. Care must be taken while designing and operating modern steam power plants. There are regulations such as German boiler regulations (Technische Regeln fur Dampfkessel 301) or European Standards that guide the user how to operate the steam power plants. However, those regulations are based on the quasi-steady state assumption and one dimensional temperature distribution in the entire element. This simplifications may not guarantee that the heating and cooling operations are conducted in the most efficient way. Thus, it was important to find an improved method that can allow to establish optimum parameters for heating and cooling operations. The optimum parameters should guarantee that the maximum total stresses in the construction element are in the allowable limits and the entire process is conducted in the shortest time. This paper summarizes mathematical descriptions how to optimize shut down process of power block devices. The optimization formulation is based on the assumption that the maximum total stresses in the whole construction element should be kept within allowable limits during cooling operation. Additionally, the operation should be processed in the shortest time possible.
Źródło:
Archives of Thermodynamics; 2011, 32, 4; 91-99
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new method for determining allowable medium temperature during transient operation of thick-walled elements in a supercritical power plant
Autorzy:
Duda, P.
Rząsa, D.
Powiązania:
https://bibliotekanauki.pl/articles/240343.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
kocioł parowy
naprężenia całkowite
optymalizacja
wymiana ciepła
heat transfer
optimization
steam boilers
total stresses
Opis:
Construction elements of supercritical power plants are subjected to high working pressures and high temperatures while operating. Under these conditions high stresses in the construction are created. In order to operate safely, it is important to monitor stresses, especially during start-up and shut-down processes. The maximum stresses in the construction elements should not exceed the allowable stress limit. The goal is to find optimum operating parameters that can assure safe heating and cooling processes [1-5]. The optimum parameters should guarantee that the allowable stresses are not exceeded and the entire process is conducted in the shortest time. In this work new numerical method for determining optimum working parameters is presented. Based on these parameters heating operations were conducted. Stresses were monitored during the entire processes. The results obtained were compared with the German boiler regulations - Technische Regeln fur Dampfkessel 301.
Źródło:
Archives of Thermodynamics; 2010, 31, 3; 55-72
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical method for determining allowable medium temperature during operation of steam gate valve
Metoda numeryczna do wyznaczania dopuszczalnego przebiegu temperatury czynnika podczas pracy zasuwy parowej
Autorzy:
Duda, P.
Rząsa, D.
Powiązania:
https://bibliotekanauki.pl/articles/369077.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
naprężenia cieplne
kocioł parowy
transfer ciepła
optymalizacja
thermal stresses
steam boilers
heat transfer
optimization
Opis:
Construction elements of power blocks such as collectors, separators or steam valves work in hazardous environment. During start-up and shut-down operations they are exposed to sudden temperature and pressure changes, that cause high stresses at certain points. Additionally, the cyclic character of loading causes material fatigue, known as low-cyclic fatigue, which may lead to the formation of fracture. Manufacturers of steam boilers provide instructions for heating and cooling processes in order to operate safely. It is important to find the optimum parameters for heating and cooling operations, i.e. parameters that enable to conduct heating and cooling in the shortest time and keep the maximum stresses in the construction within allowable limits. Efforts are made to develop an appropriate method for determining optimum operating parameters during start-up and shut-down phase of the power units. In this paper two optimum parameters will be found. Based on these parameters heating and cooling processes will be carried out and compared with heating and cooling operations processed according to the German boiler regulations Technische Regeln fur Dampfkessel 301 (TRD).
W pracy przedstawiono metodę do wyznaczenia takiego przebiegu temperatury czynnika, aby maksymalne naprężenia cieplne powstające podczas rozruchu lub odstawiania bloku energetycznego nie przekraczały naprężeń dopuszczalnych. Przy założeniu liniowej postaci przebiegu temperatury czynnika poszukiwane są dwa parametry. Przebiegi naprężeń cieplnych uzyskane przy nagrzewaniu lub ochładzaniu, przeprowadzonych według zaproponowanej metody, porównane są z przebiegami uzyskanymi na podstawie Niemieckiej Normy Technische Regeln fur Dampfkessel 301 (TRD).
Źródło:
Mechanics and Control; 2010, 29, 3; 102-109
2083-6759
2300-7079
Pojawia się w:
Mechanics and Control
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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