Wyniki wyszukiwania - Biblioteka Nauki

1

Cena zakupu energii elektrycznej z niezależnego źródła na rynku liberalizowanym

100%

Beneš M. , Vastl J.

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2002

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tom Vol. 280, z. 51

57-62

EN

The paper deals with the methodology of the calculation of "trade" interval in case of power offered by an independent power producer (IPP) to power distributor or to wholesaler of power. The left side of the trade interval is defined as a minimum power price required by the producer to reach the adequate rate of return from the investment. The minimum price is calculated from equity of discounted amount of offered electric energy and net present value of expected expenditures. The income tax and financing of the project are taken into account. The righ side of the trade interval is derived on the basis of competitive offers and reflects the "parameters" of derivered power. The methodology is derived further in the paper under assumption that the major electricity supplier must be included among the competitors.

2

Numerical simulation of NO production in a pulverized coal fired furnace

80%

Straka R. , Makovička J. , Beneš M.

Environment Protection Engineering

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2011

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tom Vol. 37, nr 2

13-22

EN

Behaviour of air-coal mixture has been described using the Navier-Stokes equations for the mixture of air and coal particles, accompanied by the turbulence model. The undergoing chemical reactions are described by the Arrhenius kinetics (reaction rate proportional to exp(-E/RT) ). Heat transfer via conduction and radiation has also been considered. The system of partial difference equations is discretized using the finite volume method and the advection upstream splitting method as the Riemann solver. The resulting ordinary differential equations are solved using the 4th order Runge-Kutta method. Results of simulation for typical power production level are presented together with the air staging impact on NO production.

3

Heat flow through a thin cooled pipe filled with a micropolar fluid

80%

Beneš M. , Pažanin I. , Suárez-Grau F. J.

Journal of Theoretical and Applied Mechanics

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2015

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tom Vol. 53 nr 3

569--579

EN

In this paper, a non-isothermal flow of a micropolar fluid in a thin pipe with circular cross- -section is considered. The fluid in the pipe is cooled by the exterior medium and the heat exchange on the lateral part of the boundary is described by Newton’s cooling condition. Assuming that the hydrodynamic part of the system is provided, we seek for the micropolar effects on the heat flow using the standard perturbation technique. Different asymptotic models are deduced depending on the magnitude of the Reynolds number with respect to the pipe thickness. The critical case is identified and the explicit approximation for the fluid temperature is built improving the known result for the classical Newtonian flow as well. The obtained results are illustrated by some numerical simulations.

4

The Influence of Burner Locations in the Heating Furnace on the Charge Temperature Field

61%

Rywotycki M. , Szajding A. , Malinowski Z. , Telejko T. , Gołdasz A. , Beneš M.

Archives of Metallurgy and Materials

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2015

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tom Vol. 60, iss. 3A

1981--1985

EN

Charge heating in industrial furnaces is a difficult and complex process. There are many physical phenomena which influence heat transfer. At the charge surface heat transfer takes place by radiation and convection. In order to ensure correct operation of the technological system, it is necessary to achieve the required charge temperature in the whole volume and ensure its uniformity. The influence of selected burner locations inside the furnace on the charge temperature has been analysed. The temperature field and its uniformity in the round charge made of steel for hot open die forging have been analysed. The model and numerical calculations were performed with the ANSYS-Fluent 14.5 package.

PL

Nagrzewanie wsadu w piecach przemysłowych jest trudnym i złożonym procesem. Celem zapewnienia prawidłowej pracy ciągu technologicznego konieczne jest osiągnięcie przez wsad wymaganej temperatury w całej objętości, oraz zapewnienie odpowiedniej równomierności nagrzewania. W pracy określono wpływ sposobu nagrzewania wsadu w piecu komorowym dla wybranych wariantów usytuowania palników grzewczych. Analizie poddano pole temperatury i jego jednorodność w nagrzewanym wsadzie stalowym przeznaczonym do przeróbki plastycznej. Model i obliczenia wykonano pakietem numerycznym ANSYS-Fluent 14.5.