Browsing by Author "Branny, Marian"

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Access status: Open Access ,
Air flow measurements through the laboratory stand of the crossing of the long wall and ventilation gallery for CFD code validation
(2012) Branny, Marian; Karch, Michał; Wodziak, Waldemar; Szmyd, Janusz; Jaszczur, Marek; Nowak, Remigiusz
W pracy prezentowane są wyniki badań eksperymentalnych i numerycznych przepływu powietrza przez układ przewodów wentylacyjnych (wyrobisk) w kształcie litery T. Model laboratoryjny jest pewnym uproszczeniem układu wyrobisk skrzyżowania ściany z chodnikiem wentylacyjnym. Uproszczenia dotyczą zarówno geometrii obiektu jak i warunków przepływu. Stanowisko laboratoryjne składa się z kanału dolotowego (końcowy fragment ściany), wnęki i kanału wylotowego (chodnik wentylacyjny) na którego końcu zainstalowano wentylator pracujący w trybie ssącym. Celem przeprowadzonych badań jest próba oszacowania dokładności z jaką symulacje numeryczne odwzorowują przepływ fizyczny. Pomiary prędkości wykonywano metodą PIV (Particle Image Velocimetry). Istota pomiaru polega na statystycznym oszacowaniu ruchu cząstek wskaźnikowych wymieszanych z powietrzem, których ruch rejestrowany jest przez kamerę cyfrową. Cyfrowa rejestracja i korelacja obrazów cząstek umożliwia określenie składowych wektora prędkości w całym obszarze przepływu. Symulację numeryczną przepływu powietrza, dla warunków identycznych jak w badaniach eksperymentalnych wykonano metodą CFD (Computational Fluid Dynamics) przy użyciu programu FLUENT. W pracy testowano dwa modele turbulencji: standardowy k-epsilon i jego modyfikację model RNG k-epsilon. Pomiary wykonano dla średniej prędkości przepływu równej 9,85 m/s czyli przy liczbie Reynoldsa wynoszącej 148 600. Wyniki eksperymentalne porównano z wynikami symulacji numerycznych. Wykonane badania pozwalają na ocenę dokładności z jaką symulacje numeryczne odwzorowują przepływ rzeczywisty. Największe różnice między zmierzonym i obliczonym polem prędkości występują w strefie wnęki. W tej części obszaru przepływu model k-epsilon lepiej niż RNG k-epsilon przybliża warunki rzeczywistego przepływu. Pole prędkości w kanale dolotowym jak i na początku kanału wylotowego obliczane jest z zadawalającą dokładnością jakkolwiek w strefie przepływu wtórnego różnice pomiędzy pomiarami i obliczeniami są znaczące. Dobrą zgodność pomiarów z obliczeniami w tym fragmencie obszaru przepływu uzyskuje się przy użyciu modelu RNG k-epsilon.
Access status: Restricted ,
Analiza pola prędkości metodą PIV za łopatkami nawiewnika
(Data obrony: 2017-01-25) Gołda, Paweł
Wydział Energetyki i Paliw
Access status: Open Access ,
Analiza pola prędkości w wyrobiskach przewietrzanych przez dyfuzję
(Wydawnictwa AGH, 2010) Branny, Marian; Filipek, Wiktor; Karch, Michał
Ventilation of short blind heading caused by through road air velocity is considered. A series of numerical tests was performed to determine the effect of different through air velocities on airflow patterns. The velocities ranged between 0,65 m/s and 2,1 m/s. 3D velocity fields was calculated using a finite-volume CFD computer code FLUENT 6.1. Two turbulence models (standard k- and RNG k-) as well as two near-wall models (wall function and enhanced wall treating) were tested. Numerical results were compared with experimental data.
Access status: Restricted ,
Badania chłodziarki powietrza z poślizgiem temperatury czynnika chłodniczego i wewnętrznym wymiennikiem ciepła
(Data obrony: 2012) Życzkowski, Piotr
Wydział Górnictwa i Geoinżynierii
In a dissertation a mathematical description of work of air indirect refrigerator type TS-450P in steady state with temperature glide during phase change of the refrigerant R407C and the presence of an internal heat exchanger was presented. Created mathematical model includes following equations: the power equations of heat exchangers, isenthalpe equation for the expansion valve and refrigerant vapour compression equation with the isentropic efficiency. Proving linear variation of isobars during phase change of refrigerant R407C, the phenomenon of temperature glide was included in the calculation of evaporator. Thermodynamic and transport properties of R407C refrigerant were described by 23 relationships for the subcooled region, saturated liquid, two-phase region, saturated vapour and superheated vapour. Obtained results were compared with in situ measurements of the refrigerator parameters. The results of the dissertation can be used in practice, not only in the description of the TS-450P refrigerators parameters, but also in calculations, which require knowledge of the thermodynamic and transport properties of R407C refrigerant.
Access status: Open Access ,
Badania modelowe hydrodynamicznych własności ośrodków porowatych zbudowanych z sieci komórek elementarnych
(2010-03-04) (Data obrony: 2012) Filipek, Wiktor
Wydział Górnictwa i Geoinżynierii
The author presents an original concept of modelling the flow of viscous fluid through a porous medium. In the method developed in this doctoral dissertation, the movement of fluid in the medium which is made of identical spheres has been presented by analyzing the flow in the model formed from so-called 'elementary cells' - virtual creations, to which, by assumption, the pore space of real medium was divided. The correctness of this model has been verified by experimental tests carried out by the author personally. The obtained compatibility of computational model with empirical results is important in this case and justifies the application of the formulated theoretical and computational model to situations that could not be tested experimentally. Although the method seems to be universal, nevertheless, the research area has been limited to laminar flow only and the porous medium to the one made of identical spheres. However, there are no significant obstacles to the application of the method to the porous media of a different structure, such as the medium whose frame is constructed of triaxial ellipsoids of the same shape. It is an important achievement of the research project to demonstrate - on the basis of simulation calculations - a direct relationship between the intensity of fluid motion vorticity and the size of the deviation from the Darcy's formula which expresses the linear relationship between the filtration rate and pressure gradient.
Access status: Open Access ,
Chłodzenie powietrza w wyrobiskach chłodziarką sprężarkową o działaniu bezpośrednim
(Wydawnictwa AGH, 2011) Branny, Marian; Filek, Krzysztof; Swolkień, Justyna
Problem of air-cooling in blind headings with duct, exhausting systems of ventilation is considered. Performance of two types of compression refrigerators were tested. Calculations were made for different volume flows of air through evaporator and for different air temperatures in heading. Parameters of cooled air and cooling power of evaporators were calculated using mathematical model of compression refrigerator developed in [1]. The results of calculations are presented in the form of plots and tables. Cooling power of evaporators and its division on sensible and latent part was shown on diagrams.
Access status: Open Access ,
Dwufazowy przepływ powietrza i wody w pionowych wyrobiskach górniczych
(2008) Branny, Marian; Filek, Krzysztof; Nowak, Bernard; Ptaszyński, Bogusław
The article describes examples of two-phase flows in mining excavations and its impact on ventilation systems. Author discusses some of flows features, parameters and its theoretical models. The article presents computational model of two-phase flows in vertical expiratory shaft, using Euler-Lagrange's method. Numerical simulations were performed with the discrete phase model implemented using computational fluid dynamics (CFD) software- Fluent. Calculations results presented in the form of graphs are enclosed.
Access status: Restricted ,
Koszty zużywanej energii w obiekcie mieszkalnym i metody ich obniżenia
(Data obrony: 2011-06-21) Łysak, Przemysław
Wydział Górnictwa i Geoinżynierii
Access status: Open Access ,
Kształt pola prędkości w wyrobiskach przewietrzanych wentylatorami wolnostrumieniowymi - symulacja numeryczna przy użyciu lepkościowych modeli turbulencji
(Wydawnictwa AGH, 2010) Branny, Marian; Filek, Krzysztof; Nowak, Bernard
Room and pillar headings are frequently ventilated with the use of jet fans. The range of penetration of an air stream generated by the jet fan is determined by several parameters; the major determinants being the initial stream parameters and the place of fan's installation. The paper presents a method of calculation 3D velocity fields in room and pillar headings. Results obtained with the use of three turbulence models, it is two equations model k-l i k-u SST and one equation of Spalart-Allmaras. Calculation were compared with measurements [Meyer 1993].
Access status: Restricted ,
Metoda oceny efektywności pracy górniczych chłodziarek bezpośredniego działania na przykładzie typoszeregu TS
(Data obrony: 2012) Łuczak, Rafał
Wydział Górnictwa i Geoinżynierii
In a dissertation, an assessment of work effectiveness of mining direct TS type refrigerators was made by using results of measurements attained on the laboratory stand and in mine excavations. In view of using effectiveness of cooling power, the air cooling efficiencies of TS-300 and TS-350 refrigerators were studied. The assessment of these systems work was performed on the basis of created criterial equations. Indicated equations include the influence of cooling air parameters and condenser cooling water parameters on a heat power of refrigerant evaporators. To their indication the methods of Multiple Regression and linear estimate were used. Moreover, the linear and non-linear statistical models evaluate the work efficiency of each system. Subsequent models in simple form were created by using a modification of coefficient and exponent values at independent variables, but in a manner as not to affect the quality of mathematical description. Obtained results were compared to measurements and determined the absolute and relative deviation of evaporator power. On the basis of indicated statistical equations with modified coefficient and exponent values, the temperature and humidity prediction of cooling air was performed. The proposed criterial equations allow correctly select the heat power of refrigerants during the designing and respond to possible irregularities in work during their exploitation.
Access status: Open Access ,
Model fazy dyskretnej przepływu powietrza z wykropleniem pary wodnej
(Wydawnictwa AGH, 2010) Branny, Marian; Nowak, Bernard; Ptaszyński, Bogusław; Kuczera, Zbigniew; Łuczak, Rafał; Życzkowski, Piotr
The paper describes the use of the discrete phase model to describe the movement of air in the vertical ventilation shafts with condensation of water vapor. Conditions under which discrete phase model can be used were verified and the results of performed calculations were presented. The results were obtained fo vertical movement up to the drops of water in the shaft.
Access status: Open Access ,
Możliwości ograniczenia szkodliwego wpływu wód dołowych na stan rurociągów kolektora Olza i środowisko rzeki Odry
(2006-02-02) (Data obrony: 2008) Swolkień, Justyna
Wydział Górnictwa i Geoinżynierii
The doctoral thesis describes issues related with possibilities of reduction of mine waters harmful influence on an environment of Odra river. This waters come from south-western part of the Upper Silesian Coal Basin and are transported directly do the river through the interceptor sewer called "Olza". The studies of strongly contaminated mine waters (mostly with chlorides, sulphates, barium and suspension) allowed to prepare a computer program called "Dyspozytor". It helps to determine what kind of water class is possible to be obtain taking into consideration river flow and its earlier contamination. It also allows to optimize pump stations functioning. The second issue concerns problems of precipitation of $BaSO_4$ inside the pipelines during transportation through the interceptor sewer. BaSO4 sediment comes from mixing chemically different waters. Using Computational Fluid Dynamics methods it was possible to describe efficiency of $BaSO_4$ sedimentation in settling tank. This knowledge allows to prevent BaSO4 sedimentation in the pipelines which is important due to their technical condition.
Access status: Open Access ,
Numeryczna symulacja procesu wentylacji w wyrobiskach ślepych
(Wydawnictwa AGH, 2005) Branny, Marian
The study explores the potential of numerical modelling of airflow in blind headings. The main focus is forecasting the ventilation parameters in headings and galleries characteristic of copper mines belonging to the LGOM Corporation. The fundamentals of mathematical modelling of turbulent flows are provided. The model makes use of 3D continuity and Rynolds equations, the equation of turbulent transport of chemical components and the equations of the k-$\epsilon$ model (kinetic energy of turbulence, the rate of kinetic energy dissipation). The discretisation procedure involved the control volume method and the technique UPWIND. The developed numerical codes employ the hybrid schemes and power-law techniques. Nonlinear systems of discrete equations were solved with the use of SIMPLER procedures. 3D velocity fields and gas concentrations calculated for galleries are provided. The chief objective is to eliminate the hazardous conditions caused by the presence of gas pollutants emitted by diesel-powered engines in machines and produced in the course of blasting operations. The results of numerical solutions of steady-state velocity field and the time-space field of concentration of gaseous pollutant emitted by lumped or distributed gas sources are presented. The accuracy of numerical representation is evaluated by comparing the prognosticated values with measurements. The obtained physical fields by way of numerical procedures portray the real fields sufficiently well for practical purposes
Access status: Restricted ,
Planowane!
Ocena skuteczności odpylania powietrza w wyrobiskach drążonych kombajnami w warunkach zagrożenia metanowego
(Data obrony: 2006) Krzykowski, Ryszard
Wydział Górnictwa i Geoinżynierii
W pracy przeprowadzono ocenę zagrożenia pyłami szkodliwymi dla zdrowia w wyrobiskach drążonych kombajnami chodnikowymi. Scharakteryzowano czynniki wpływające na stan zapylenia powietrza. Wskazano na istotne problemy wynikające z braku poprawnej współpracy wentylacji kombinowanej z instalacją odpylającą w warunkach wysokiej metanowości wyrobisk chodnikowych. Stwierdzono, że stosowanie instalacji odpylającej w polskich kopalniach węgla kamiennego pozwala na obniżenie stężenia pyłu na stanowiskach pracy do wartości maksymalnie czterokrotności przekroczenia Najwyższych Dopuszczalnych Stężeń pyłu węglowego. Na podstawie przeprowadzonych pomiarów kopalnianych w 15 wyrobiskach z wentylacją kombinowaną z zasadniczym lutniociągiem tłoczącym stwierdzono, że o skuteczności redukcji stężenia pyłu w powietrzu decyduje nie tylko skuteczność urządzenia odpylającego ale również zachowanie proporcji pomiędzy strumieniem powietrza doprowadzanego do przodka a wydajnością odpylacza. Zwiększenie udziału powietrza w strefie zazębiania jest korzystne z uwagi na stężenie metanu lecz wpływa niekorzystanie na skuteczność redukcji zapylenia powietrza. Wzrost głębokości prowadzenia robót górniczych wymaga także zwiększenia strumienia powietrza doprowadzanego do przodka z uwagi na warunki klimatyczne, nawet w polach niemetanowych. Dla ograniczenia strumienia powietrza w strefie zazębiania w wyrobiskach drążonych w polach niemetanowych lub o małej metanowości niezbędne byłoby wprowadzenie płynnej regulacji strumienia powietrza w lutniociągu zasadniczym. Na podstawie prowadzonych badań zaproponowano opracowanie i wdrożenie odpylaczy o większych wydajnościach.
Access status: Open Access ,
Ocena stanu zagrożenia metanowego w południowo-wschodniej części Górnośląskiego Zagłębia Węglowego
(2007-12-20) (Data obrony: 2009) Sporysz, Grzegorz
Wydział Górnictwa i Geoinżynierii
In this paper methane hazard degree in the coal seam in south-eastern part of Upper Silesian Coal Basin was estimated by means of such parameters as: methanebearing capacity determined by the direct method and methane desorption intensity rate and pressure of methane in coal deposit specified by desorbometric methods. Analysis treated 1680 findings concerning methane hazard degree parameters as appearing in the area of mining "Brzeszcze II" and 376 findings from the mining area "Czechowice II". Statistical relationships between these parameters were estimated as well as the impact on them of such factors as: geological structure of the region, seam depth, volatile content, ash content, moisture content, existing state of gas relations in the deposit. A high correlation has been stated between methanebearing capacity, and pressure of methane in coal deposit and also methane desorption intensity rate. Geological disturbances, especially tectonic faults form a path of methane migration in the deposit. They create the degassing zone of methane and thereby reduce the risk status of methane in the case of the meridional faults and the accumulation of methane and higher state of threat in the vicinity of the parallel faults. A comparative analysis has also been made concerning average methane absolute emission obtained in the course of wall exploitation and the forecast method developed by CBiDGP.
Access status: Open Access ,
Próba opisu zjawiska prądów wstecznych metodami CFD
(2006) Branny, Marian; Broda, Krzysztof; Filek, Krzysztof; Mikołajczyk, Władysław
An attempt to describe the reverse flow phenomena through numerical simulation was undertaken in this paper. The flow domain creates a 150 m long declined gallery with 15 degrees angle of inclination. The airflow is descending in isotropic conditions. In 10 m long gallery's section a hihger temperature of foor and roof than on remining rock surfaces was assumed. The cosidered problem is described by a system of equations of continuity, Navier-Stokes and energy together with k-epsylon turbulence model. The calculations were performed for different wall temperatures of heated gallery's section. The flow field patterns, characterizing the respective stages of reverse flow expasion are analyzed. CFD code validation based on the experimental data were performed. The numerical calculations by the programme FLUENT 6.1 have been supported.
Access status: Open Access ,
Prognozowanie temperatury powietrza w przodkach wyrobisk ślepych przewietrzanych wentylacją lutniową - 3D symulacja komputerowa
(Wydawnictwa AGH, 2009) Branny, Marian; Filipek, Wiktor; Karch, Michał
The solution is supported by equations and simulation programs utilizing the CFD approach. The description of wall boundary conditions utilizes the modify wall function. The temperature of side walls was obtained from the solution of a substitute problem. This temperature is a result of the solution of equation of heat conduction with boundary conditions describing the exchange of heat between the rock and the flowing air. The influence of evaporating water on air temperature was taken into consideration. The volumetric source of heat (negative) was defined in energy equation. The source terms were located in group of cells adjacent to the wall. Calculation data are presented in the form of velocity field and air temperature images in the face zone of a working with a force-exhaust overlap system of ventilation.
Access status: Open Access ,
Prognozowanie warunków klimatycznych dla ścian o wysokiej koncentracji wydobycia
(2005-01-27) (Data obrony: 2011) Kapusta, Mariusz
Wydział Górnictwa i Geoinżynierii
The doctoral dissertation presents scientific research aiming at forecasting temperature and humidity at the outlet of longwall excavation with high exploitation concentration. The object of the research are air thermodynamical parameters and the alterations of the air stream which flows along a longwall excavation. Appropriate assessment of the temperature hazard has underground exploitation excavations. Measurements of the air parameters demonstrated the change of the distribution of the air stream in the wall directly associated with the applied system of airing the excavation. The method of determining the quantity of heat originating from the abandoned workings, which was classified as an additional source of heat, was proposed. The impact of the heat from the abandoned workings on the alteration of the temperature and humidity when forecasting the heat conditions was determined. The research conducted during the operation and stoppage of electrical appliances made it possible to examine the inflow of heat from the energomechanical appliances and machines. When calculating the quantity of overt and latent heat flowing from the appliances to the air, the impact of that factor on the temperature and humidity in the wall was determined. The results of the research enabled to modify the method of forecasting the temperature and humidity in longwall excavations with high exploitation concentration. Considering in the assessment the additional heat inflow from the abandoned workings and appropriate calculation of the heat transmitted from electrical appliances makes it possible to reflect the actual process of heat and humidity exchange in a longwall excavation.
Access status: Open Access ,
Sposób wykonywania obudowy szybu odcinkami z góry w dół w zamrożonym górotworze opis patentowy nr 208175
(Urząd Patentowy Rzeczypospolitej Polskiej, 2011-03-31) Czaja, Piotr; Hydzik-Wiśniewska, Joanna; Branny, Marian; Akademia Górniczo-Hutnicza im. Stanisława Staszica (Kraków)
Access status: Open Access ,
Wartości współczynników wymiany ciepła i masy w wentylatorowej wyparnej chłodnicy wody
(Wydawnictwa AGH, 2010) Nowak, Bernard; Filek, Krzysztof; Branny, Marian
Results of experimental studies of the performance of fan evaporative type of water coolers are presented in this paper. Tests were conducted with two types of coolers - RK-450 and CWW-420. Parameters of cooled and spray water and of the air were measured. On the base of data collected during laboratory experiments, coefficients of heat and mass exchange were calculated for both tested coolers. Among this coefficient are: overall heat-transfer coefficient through membrane (k), convective heat-transfer coefficient (alpha) and coefficient of mass exchange (P) between spray water and the air. There were determined regression lines and coefficients of linear correlation for k and a in dependence of inlet water temperature. The results of experiments and calculations are presented in the form of plots and tables.