Wyniki wyszukiwania - BazTech

1

Symulacja obliczeniowa mikroklimatu w klimatyzowanych budynkach zabytkowych na przykładzie Sukiennic

Sadłowska-Sałęga A., Radoń A., Gryc A.

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2018

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T. 49, nr 11

466--473

PL

Obliczeniowe symulacje cieplno-wilgotnościowe klimatyzowanych budynków są niezbędne do określenia kształtowania się warunków mikroklimatycznych oraz zużycia energii na poszczególne procesy uzdatniania powietrza przy różnych scenariuszach kontroli. Ze względu na specyfikę budynków historycznych wyniki obliczeń powinny zostać poddane walidacji porównawczej, najlepiej z wynikami pomiarów eksperymentalnych. Wymagana dokładność modelu definiowana jest przez konserwatorów. Wynika ona z określenia wrażliwości tzw. funkcji uszkodzeń kolekcji na parametry mikroklimatu pomieszczeń muzealnych lub przechowalniczych. Celem pracy jest przedstawienie możliwości i ograniczeń wyznaczenia kształtowania mikroklimatu budynku zabytkowego na drodze obliczeniowej. Cel ten jest osiągnięty przez pokazanie złożonego procesu walidacji modelu obliczeniowego na przykładzie Sukiennic. Obliczenia teoretyczne kształtowania się mikroklimatu oraz zużycia energii przeprowadzono za pomocą programu WUFI ®plus. Do walidacji modelu posłużyły dane pomiarowe zebrane w ramach projektu Heriverde: Efektywność energetyczna instytucji muzealnych i bibliotecznych. Pomimo wielu niepewności dotyczących warunków brzegowych oraz pracy systemów HVAC uzyskano, na drodze iteracyjnej kalibracji, co najmniej dopuszczalną dokładność modelu. Jednakże każdy budynek historyczny należy traktować jako studium przypadku.

EN

Hygrothermal simulations of air-conditioned buildings are necessary to determine the formation of microclimatic conditions and energy consumption for individual air treatment processes in various control scenarios. Due to the specificity of historical buildings, the results of calculations should be subject to comparative validation, preferably with the results of experimental measurements. The required accuracy of the model is defined by the conservators. It results from the determination of the sensitivity of the so- damage functions to the microclimate parameters of museum or storage rooms. The aim of the work is to present the possibilities and limitations of determining the microclimate of a historic building on a computational basis. This goal is achieved by showing a complex process of validation of the computational model on the example of the Sukiennice. Theoretical calculations of microclimate formation and energy consumption were carried out using the WUFI®plus program. The measurement data collected as part of the Heriverde project, were used to validate the model. Despite a series of uncertainties regarding the boundary conditions and operation of HVAC systems, it was obtained, by iterative calibration, at least the acceptable accuracy of the model. However, every historical building should be treated as a case study.

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The Microstructure of WE43 MMC Reinforced with SiC Particles

Dybowski B., Rzychoń T., Chmiela B., Gryc A.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 1

393--398

EN

It is well known that the properties of a metal matrix composites depend upon the properties of the reinforcement phase, of the matrix and of the interface. A strong interface bonding without any degradation of the reinforcing phase is one of the prime objectives in the development of the metal matrix composites. Therefore, the objective of this work is to characterize the interface structure of WE43/SiC particles composite. Magnesium alloys containing yttrium and neodymium are known to have high specific strength, good creep and corrosion resistance up to 250°C. The addition of SiC ceramic particles strengthens the metal matrix composite resulting in better wear and creep resistance while maintaining good machinability. In the present study, WE43 magnesium matrix composite reinforced with SiC particulates was fabricated by stir casting. The SiC particles with 15 μm, 45 μm and 250 μm diameter were added to the WE43 alloy. The microstructure of the composite was investigated by optical microscopy, scanning electron microscopy, scanning transmission electron microscopy and XRD analysis. YSi and Y2Si reaction products are observed at the interfaces between SiC particles and WE43 matrix in the composite stirred at 780°C. Microstructure characterization of WE43 MMC with the 45 μm, stirred at 720°C showed relative uniform reinforcement distribution. Moreover, the Zr-rich particles at particle/matrix interface were visible instead of Y-Si phases. In the case of composite with 15 μm particles the numerous agglomerates and reaction products between SiC particles and alloying elements were observed. The presence of SiC particles assisted in improving hardness and decreasing the tensile strength and plastic properties.

3

Characterisation of Microstructure of We43 Magnesium Matrix Composites Reinforced with Carbon Fibres

Gryc A., Rzychoń T.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2B

1075--1081

EN

In the paper the microstructures of WE43 matrix composites reinforced with carbon fibres have been characterised. The influence of reinforcement type and T6 heat treatment (a solution treatment at 525°C for 8 h, a hot water quench and a subsequent ageing treatment at 250°C for 16 h) on microstructure have been evaluated. The light microscope and scanning electron microscope investigations have been carried out. No significant differences in samples reinforced with non-coated textiles have been reported. The substantial changes in sample reinforced with nickel-coated textile have been observed. The segregation of alloying elements to the matrix-reinforcement layer has been identified. The T6 heat treatment caused the appearance of disperse precipitates of β phase, but the process cannot be considered as satisfactory (irregular distribution, low volume fraction, relatively large size).

4

Measurements and calculations of temperature in the ground and in assemblies adjacent to an intermittently heated basement

Gryc A., Radoń J., Nawalany G.

Czasopismo Techniczne. Budownictwo

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2015

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Y. 112, iss. 1-B

33--42

EN

Cellars of the main building of the University of Agriculture in Krakow are used as storage areas, laboratories and as classrooms. This article presents the results of many years of temperature measurements in one cellar room; internal and external air temperature as well as temperatures of the walls, the floor and adjacent ground were recorded. In the winter season, the examined room was intermittently heated. Using measured boundary conditions, transient, three-dimensional heat flow in the basement foundation interface was calculated. WUFI®Plus software was used for calculation. By means of statistical analysis, the calculated temperature distribution in assemblies and the ground was then compared with the measurement results. The analysis allowed for the determination of the accuracy of theoretical calculations of thermal conditions in the environment of the periodically heated cellar room.

PL

Piwnice w budynku głównym Uniwersytetu Rolniczego w Krakowie są używane jako magazyny, laboratoria oraz sale lekcyjne. Artykuł prezentuje wyniki wieloletnich pomiarów w pomieszczeniu piwnicznym; temperatury powietrza wewnętrznego i zewnętrznego, ścian, podłogi oraz w gruncie. W zimie piwnica była ogrzewana z przerwami. Obliczenia trójwymiarowego, niestacjonarnego przepływu ciepła wykonano, wykorzystując pomierzone warunki brzegowe. Do obliczeń zastosowano program WUFI®Plus. Wyniki pomiarów i obliczeń temperatury w przegrodach i gruncie porównano statystycznie. Wyniki pozwoliły określić dokładność obliczeń warunków termicznych wokół piwnicy okresowo ogrzewanej.

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Mechanical Properties and Microstructure of WE43 Magnesium Matrix Composite Reinforced SiC Particles

Rzychoń T., Dybowski B., Gryc A., Dudek M.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 1 spec.

99--102

EN

Magnesium alloys containing yttrium and neodymium are known to have high specific strength, good creep and corrosion resistance up to 250°C. The addition of ceramic particles strengthens the metal matrix composite resulting in better wear and creep resistance while maintaining good machinability. In the present study, WE43 magnesium matrix composite reinforced with SiC particles were fabricated by stir casting. The microstructure of the composite was investigated by optical microscopy, quantitative metallography, scanning electron microscope and XRD analysis. Microstructure characterization of WE43 MMC showed homogeneous reinforcement distribution and presence of the small amount of porosity at the interface. A thin layer consists of zirconium-rich particles was observed at the interface. In the microstructure, inclusions of the yttrium oxide were found. The presence of SiC particles assisted in improving hardness and in decreasing the ultimate tensile strength, yield tensile strength and elongation.

6

Ocena komfortu cieplnego pomieszczenia biurowego w piwnicy w świetle badań eksperymentalnych

Gryc A., Radoń J.

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2011

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T. 42, nr 5

217-219

PL

W artykule przedstawiono wyniki badań temperatury i wilgotności powietrza w piwnicy budynku Uniwersytetu Rolniczego w Krakowie, które wskazują, że pomimo odpowiedniej temperatury powietrza wewnętrznego, okresowo występuje uczucie zimna. Ten rodzaj dyskomfortu powodowany jest niską temperaturą powierzchni przegród, przylegających do gruntu.

EN

The paper presents the results of air temperature and humidity in the basement of the Agricultural University in Krakow. They indicate that despite adequate internal air temperature, there periodically appears a feeling of cold. This type of discomfort is caused by the low surface temperature of the compartments adjacent to the ground.