Wyniki wyszukiwania - BazTech

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Investigation of climate effects on the performance of solar chimney power plants using numerical and analytical models: A case study for Chlef, Algeria

Nouar Hadda, Tahri Toufik, Benyoucef Djilali, Chaiba Younes, Denai Mouloud, Azizi Abdelghani

Przegląd Elektrotechniczny

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2021

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R. 97, nr 3

113--118

EN

In this work, a semi-empirical model and 2D numerical model were developed to evaluate the Solar Chimney Power Plant (SCPP) efficiency in Chlef, Algeria. The airflow through the solar chimney is treated as a compressible flow in contrast to the Boussinsq model. In addition, the pressure and temperature in the solar are considered not constant. Thus, modelling was carried by means of Renolds Averaged Navier-Stokes (RANS) equations coupled to the k-ε turbulence model. The meteorological parameters used in this study such as the temperature and the global solar radiation were measured in the Chlef region, Algeria, during 2018. The power output, updraft velocity and temperature were calculated and compared with the experimental results obtained from the Manzanares prototype to validate results of the compressible flow through the solar chimney obtained with the 2D numerical model are more accurate than those produced by Bossinsq model. The COMSOL Multiphysics software was used in this study to simulate the SCPP flow behaviour. Results demonstrate that the proposed numerical model derived from fundamental engineering calculations is reasonably accurate and can be effectively applied to investigate the SCPPs efficiency.

PL

Przedstawiono model solarnego kominowego źródła energii zaprojektowanego w Chief – Algeria. Przepływ nagrzanego powietrza przez komin uruchamia turbinę wiatrową. Do opisu wykorzystano równania Renolds Averaged Navier-Stokes. Do obliczeń wykorzystano typowe warunki atmosferyczne w Chief. Symulację przeprowadzono wykorzystując oprogramowanie COMSOL Multiphysics.

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Investigation of climate effects on the performance of solar chimney power plants using numerical and analytical models: A case study for Chlef, Algeria

Nouar Hadda, Tahri Toufik, Benyoucef Djilali, Chaiba Younes, Denai Mouloud, Azizi Abdelghani

Przegląd Elektrotechniczny

|

2021

|

R. 97, nr 3

113--118

EN

n this work, a semi-empirical model and 2D numerical model were developed to evaluate the Solar Chimney Power Plant (SCPP) efficiency in Chlef, Algeria. The airflow through the solar chimney is treated as a compressible flow in contrast to the Boussinsq model. In addition, the pressure and temperature in the solar are considered not constant. Thus, modelling was carried by means of Renolds Averaged Navier-Stokes (RANS) equations coupled to the k-ε turbulence model. The meteorological parameters used in this study such as the temperature and the global solar radiation were measured in the Chlef region, Algeria, during 2018. The power output, updraft velocity and temperature were calculated and compared with the experimental results obtained from the Manzanares prototype to validate results of the compressible flow through the solar chimney obtained with the 2D numerical model are more accurate than those produced by Bossinsq model. The COMSOL Multiphysics software was used in this study to simulate the SCPP flow behaviour. Results demonstrate that the proposed numerical model derived from fundamental engineering calculations is reasonably accurate and can be effectively applied to investigate the SCPPs efficiency.

PL

Przedstawiono model solarnego kominowego źródła energii zaprojektowanego w Chief – Algeria. Przepływ nagrzanego powietrza przez komin uruchamia turbinę wiatrową. Do opisu wykorzystano równania Renolds Averaged Navier-Stokes. Do obliczeń wykorzystano typowe warunki atmosferyczne w Chief. Symulację przeprowadzono wykorzystując oprogramowanie COMSOL Multiphysics.

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Numerical prediction of thermal performance of an electrocaloric device based on ceramic material

Kehileche Brahim, Chiba Younes, Tlemcani Abdelhalim, Henini Noureddine

Przegląd Elektrotechniczny

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2020

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R. 96, nr 9

38--42

EN

The main objective of this work is to efficiency prediction and parameter optimisation of an electrocaloric refrigeration system based on ceramic materials (BaTiO3) and nanofluids (Al2O3, CuO). For this purpose, an electrocaloric device is used and studied. The principle consists in the heating and cooling of the ceramic material under the application and removal of electrical field respectively. The nanoparticles suspended in water increase the heat thermal between solid electrocaloric material and carried fluid, so we have much faster heat exchanges that cause an increase in coefficient of performance (COP) and temperature span; the temperature difference between the cold heat exchanger (CHEX) and the hot heat exchanger (HHEX). Indeed, the performances of these systems are strongly dependent on the interactions between the thermal, the fluidic and the electricity in order to be able to evaluate and optimize these systems in terms of cooling power, and the observation is that there are very few current studies in this area. Finally, a parametric study effected by using the COMSOL Multiphysics identified the characteristic quantities that have a significant influence on thermal behavior in electrocaloric refrigeration systems based nanofluids and ceramic material.

PL

Tematem artykułu jest analiza i optymalizacja systemu chłodzenia bazującego na materiale ceramicznym BaTiO3 i nanocieczy Al2O3, CuO. W tym celu analizowano element elektrokaloryczny I współczynnik wymiany ciepła CCP. Przedstawiono wyniki badań elementu jak I całego systemu chłodzenia.

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Obliczenia numeryczne rozkładu temperatury w transformatorze dystrybucyjnym

Gościński P., Dombek G., Nadolny Z., Bródka B.

Przegląd Elektrotechniczny

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2016

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R. 92, nr 10

46--49

PL

W artykule przedstawiono porównanie wyników symulacji komputerowej i wyników pomiarów z próby nagrzewania transformatora dystrybucyjnego o mocy 10 MVA wypełnionego nowym olejem mineralnym. Następnie autorzy artykułu postanowili przeprowadzić symulację komputerową w celu porównania pola temperaturowego transformatora energetycznego wypełnionego nowym olejem mineralnym z polem temperaturowym transformatora tej samej mocy wypełnionego estrem syntetycznym.

EN

This article presents comparison between results of computer simulation and results of heat run test for 10 MVA power transformer which was filled with a new mineral oil. Later the authors of article decided to carry out computer simulation, in order to comparison the temperature field of 10 MVA power transformers which were filled a new mineral oil and a new synthetic ester.

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Modelowanie złożonej wymiany ciepła w procesie wytwarzania spieku 90W-7Ni-3Fe

Sypek J., Majewski T., Panas A.

Biuletyn Wojskowej Akademii Technicznej

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2011

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Vol. 60, nr 2

297-312

PL

Przedstawiono wyniki analizy numerycznej procesu wytwarzania metalu ciężkiego (spieku ciężkiego) 90W-7Ni-3Fe. Modelowano rzeczywisty układ stosowany do wytwarzania takiego materiału metodą nagrzewania rezystancyjnego. Do budowy modelu i wykonania obliczeń zastosowano pakiet Comsol Multiphysics. Analizę przeprowadzono przy założeniach upraszczających wynikających z ograniczonych możliwości środowiska obliczeniowego i braku pełnych charakterystyk materiałowych w całym analizowanym zakresie temperatury. W modelu odtworzono jednak wszystkie główne zjawiska i uzyskano możliwość jakościowej analizy przebiegu procesu spiekania, identyfikacji problemów technologicznych oraz optymalizacji procesu spiekania rezystancyjnego.

EN

Results of numerical analysis of 90W-7Ni-3Fe heavy alloy (WHA) production process were presented in the paper. Real system used for production of such material by resistance heating method was modelled applying Comsol Multiphysics FEM software. The analysis was focussed on complex, i.e., combined heat transfer phenomena including phase change effects. Despite some necessary simplifications, all the main phenomena were reconstructed in the numerical model. The numerical modelling enabled for qualitative and quantitative, in some aspect, analyses of the sintering processes and for identification of main technological problems. It also made possible optimisation of the analysed powder metallurgy production process.