Wyniki wyszukiwania - Biblioteka Nauki

1

HTAC Boiler Fired with Pulverized Coal for Ecologic and Efficient Electricity Production

100%

Schaffel N. , Szlęk A. , Mancini M. , Weber R.

Archivum Combustionis

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2008

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tom Vol. 28 nr 1-2

105-112

EN

The authors propose a concept of HTAC technology application to the power boilers fired with pulverized coal. So far, HTAC technology was implemented mainly in industrial furnaces fired with gaseous fuels or light oils. In order to investigate the HTAC boiler, several series of numerical simulations have been performed using FLUENT code. A specially emphasis was placed on the main technical and ecological issues that must be considered wherever HTAC technology would be applied in real power station boilers fired with pulverized coal. Mathematical model validation has been done against the experiment performed at IFRF. As an effect of several numerical investigations a final design of the HTAC boiler has been found and the results are presented and discussed in this paper. The proposed HTAC boiler features following major advantages: small size, low harmful substances emission, mainly NOx, high and uniform heat fluxes and very simple construction of the burners. Overall, the present study confirmed that HTAC technology could be a practicable, efficient and clean technology for fossil fuel fired boilers. However, it has to be pointed out that the investigated boiler is only still a concept and before any industrial application much researches have to be done.

2

The study on the effect of selected parameters of coal on its mass loss during combustion in a two-phase flow of inert material

100%

Pełka P.

Archivum Combustionis

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2011

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tom Vol. 31 nr 1-2

97-109

EN

The inspiration behind this research is the attempt to explain the mechanism of the loss of the mass of coal particles during the process of their combustion in a circulating fluidized bed. The subject of research is related to various types of Polish bituminous and lignite coal. On the basis of research carried out up to now it is well known that the process of erosion plays a significant role in the process of burning coal by changing its mechanism, as well as generating additional loss of mass. The aim of this research is to define the impact of the basic parameters of coal, i.e.: volatile matter, fixed carbon, ash content, carbon content and additionally the Hardgrove grindability index on the erosive loss of mass of the burnt particles. The combustion process in a two-phase flow of inert material modelling the conditions of fast fluidization in the dilute upper zone of the combustion chamber has been carried out. Clear correlation of mass loss of the tested particles with chemical composition of coal especially with volatile matter and ash content have been observed. The impact of the Hardgrove grindability index on the process under analysis was not however noted.

3

Węgiel - surowiec przyszłości i tworzywo dla badań naukowych

80%

Zieliński H.

Chemik

|

2000

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tom Nr 1

13-15

PL

W artykule przedstawiono argumenty za racjonalnym wykorzystywaniem węgla jako surowca do produkcji paliw płynnych. Autor uważa za niezbędne podjęcie prac badawczych w dziedzinie przetwórstwa węgla, szczególnie wobec wzrastających cen ropy naftowej i wyczerpywania się jej światowych zasobów.

EN

The article presents arguments for reasonable utilization of a coal as a raw material for liquid fuels. The author finds it necessary to undertake research works on a coal processing, particularly in view of increasing proces of a crude oil and depleting its resources in the world.

4

Department of Economic and Mining Geology

80%

Mucha J.

Geology, Geophysics and Environment

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2016

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tom Vol. 42, no. 2

223--225

5

Outburts of gas and rocks in viev of laboratory experiments

80%

Wierzbicki M.

Bulletin of the Polish Academy of Sciences. Earth Sciences

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1999

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tom Vol. 47, nr 1

63-72

EN

The results presented in this paper are a successive contribution to investigations on the couse of gas and coal outbursts phenomena, initiated under laboratory conditions. The paper presents results of experiments carried out in order to assess the impact to pressure wave reflected from the open end of the pipe on the course of the outburst. Results of subsequent experiments were divergent. Installation of additional manometers revealed assymmetry of the outburst front despite axial symmetry of the experimental stand and coal briquette. The cause of this asymmetry was briquitte. An improved design of the head was described.

6

Study on coal microstructure for porosity levels assessment

80%

Miedzińska D. , Niezgoda T. , Małek E. , Zasada D.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2013

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tom Vol. 61, nr 2

499--505

EN

The problem of methane existence in coal beds has been known for many years. It was and still it is a danger to coalminers. The aim of the research, presented in the paper, is to show and assess the porosity structure (especially micro and nanoporosity) in accordance to the dimensions of carbon dioxide particle. The characteristic surface morphology of the sample and the disclosure of the carbon porous structure have been obtained using the scanning electron microscope (SEM). The presented study of the coal microstructure is a part of the coal demethanation method with the use of liquid CO2, that has been proposed by the Military University of Technology.

7

Kotły wielopaliwowe na węgiel z ręcznym załadunkiem

80%

Ojczyk G.

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2020

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tom T. 54, nr 4

9--14

PL

W Polsce największą liczbę zainstalowanych kotłów stanowią kotły na paliwa stałe z ręcznym załadunkiem paliwa, przy czym paliwem najczęściej spalanym w tych kotłach jest węgiel kamienny. Kotły te wyposażone są w nieruchomy ruszt, przy czym mogą być one również kotłami wielopaliwowymi, tzn. można w nich spalać zarówno węgiel, jak i drewno w kawałkach stosując różne techniki spalania: spalanie górne i spalanie dolne. W artykule omówiona budowę kotłów o różnej konstrukcji oraz szczegółowo opisano zasadę ich działania

EN

In Poland, most solid fuel boilers with manual fuel loading have been installed. Hard coal is the most frequently burned fuel. These boilers are equipped with a fixed grate. These bo- ilers are multi-fuel boilers. They can be used to burn coal and wood. Various combustion techniques can be used in these boilers. Top combustion and bottom combustion. The article discusses the construction of boilers of various designs. The principle of their operation was described in detail.

8

Poziomy innowacyjności systemowej infrastruktury zasilania, informatyki i automatyki w świetle perspektyw produkcji węgla

80%

Trenczek S. , Wojtas P.

Mechanizacja i Automatyzacja Górnictwa

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2008

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tom R. 46, nr 6

55-63

PL

Scharakteryzowano infrastrukturę systemową oraz jej segmenty: zasilanie, informatykę i automatykę. Określono wpływ uwarunkowań i innych czynników na poziom jakościowy elementów infrastruktury systemowej. Przedstawiono propozycję wielokryterialnej oceny poziomu innowacyjności elementów infrastruktury. Omówiono zakres badań przeprowadzonych w ramach projektu "foresight węglowy". Przedstawiono wyniki badań poziomu istotności tych elementów przeprowadzonych w trzech grupach: gronie ekspertów z zakresu infrastruktury, ekspertów branży górniczej oraz respondentów spoza branży. Podano najważniejsze kierunki badań umożliwiających dalszy rozwój infrastruktury w perspektywie możliwości produkcji węgla kamiennego.

EN

The system infrastructure including its elements like supply, informatics and automation has been characterized in the paper. The impact of conditions as well as other factors on the quality level of the elements included in the system infrastructure has been defined. A proposal of multicriterion evaluation of innovativeness level of infrastructure elements has been presented as well. A range of research works carried out within the project "coal foresight" has been discussed. The results of research on significance level of those elements have been presented to three groups i.e. experts within infrastructure, mining experts and respondents from outside the branch of the mining industry. The most important directions of research allowing the infrastructure to be further developed regarding a potential production of hard coal have been given in the paper.

9

Kompleksowa ocena potencjalnego samozagrzewania węgla

80%

Trenczek S.

Mechanizacja i Automatyzacja Górnictwa

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2008

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tom R. 46, nr 5

3-16

PL

W artykule przedstawiono przykłady wyników badań próbek węgla z różnych grup pokładów występujących w Polsce w Górnośląskim Zagłębiu Węglowym, które potwierdzają ich niestandardowe wartości wzajemnych korelacji pomiędzy standardową temperaturą zapłonu i wskaźnikiem Grahama. Wskazano znaczenie tych różnic dla poprawności oceny poziomu zagrożenia pożarami endogenicznymi. Określono wskaźnik korygujący wyniki badań laboratoryjnego utleniania węgla z wynikami utlenianie rzeczywistego. Przedstawiono nowy wskaźnik podatności węgla na samozapłon uwzględniający niejednorodność utleniania węgla, oraz nowy sposób oceny poziomu zagrożenia potencjalnego samozagrzewania węgla. Na koniec podano weryfikację tego sposobu na pożarach zaistniałych w badanych pokładach węgla.

EN

The paper refers to the model characteristics that describe the process of coal self-heating in the context of standardized parameters of the ignition temperature and the Graham.s coefficient. Based on the investigation of coal samples taken from the selected coal seams of different parameters, this study outlines the graphics that correspond to non-standard values of mutual correlations between temperatures and the Graham.s coefficients that are typical for the samples. The focus was put on the importance of such differences to correctly evaluate hazards, and the research made it possible to define a correcting factor enabling to map the results of laboratory examination of coal oxidation onto real oxidation in coal seams. Additionally, the coefficient that reflects coal vulnerability to self-ignition was developed with account to the inconsistency of the coal oxidation process. Finally, a new method to assess the hazard level is suggested. The method takes advantage of the index of possible self-heating of coal. The index is a merge of coal seams breakdown by groups of self-ignition tendency that is currently in use, and the index of coal vulnerability to self-ignition. The verification of the new evaluation method is carried out with use of fires that had occurred in the examined coal seams.

10

Experimental testing of methanol sorption on selected coal samples from Upper Silesian Basin

80%

Baran P. , Jodłowski G. S. , Krzyżanowski A. , Zaręba K.

Geology, Geophysics and Environment

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2014

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tom Vol. 40, no. 3

261--269

EN

This paper summarises the results of methanol sorption on three selected coal samples from Polish collieries. These coals differ in terms of their degree of metamorphism (coal rank), petrography and elemental composition. It was found out that during the sorption of methanol, the sorption capacity is closely related to the structure of the coal surface and the amount of sorbed polar substance tends to decrease with the higher degree of metamorphism. Experimental data were plotted as isotherms. Empirical measurements were supported by thermodynamic analysis of aliphatic hydrocarbons sorption. The procedure is based on the Multisorption Model (MSM) designed for describing small molecules sorption in different types of carbonaceous materials (hard coals, lignites, active carbons).

11

Theoretical analysis of support stability in large dip angle coal seam mined with fully-mechanized top coal caving

80%

Ji Y. , Zhang Y. , Huang Z. , Shao Z. , Gao Y.

Mining Science

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2020

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tom Vol. 27

73--87

EN

Support stability is critical to ensure fully-mechanized top coal caving of large dip angle coal seam. To obtain the relations between each factor and hydraulic support stability, the mechanic model of large dip angle coal seam along face dip and strike was built to analyze support stability, including antitoppling, anti-slip, and anti-rotation of supports. The result indicates: Along the face dip, the suport stability was negatively correlated with dip angle; Higher top caving means lower anti-rotation at suport tail; With initial support force and working resistance of supports enhanced, the anti-slip, and antirotation stability of supports can be risen significantly. Along the strike, the critical toppling angle was proportional to dip angle, mining height, support weight, support width and support force; The critica slip angle was positive correlation with support force, friction coefficient of roof and supports. According to the results of both mechanical analysis and engineering projects, support stability in large dip angle can be risen efficiently and supports slipping, toppling and rotation can be avoided by selecting proper technical methods and equipment, like enhancing initial support force appropriately.

12

Ocena zasadności wytwarzania substytutu gazu ziemnego (SNG) z węgla kamiennego w Polsce

80%

Stańczyk K. , Kapusta K. , Jędrysik E.

Przemysł Chemiczny

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2008

|

tom T. 87, nr 4

364-370

13

Cost of mining coal as an element of multi-criteria assessment using the development measure – a case study

80%

Sulik-Górecka A. , Korban Z.

Management Systems in Production Engineering

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2018

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tom nr 3 (26)

162--167

EN

The paper presents the possibilities of applying one of the multi-criteria assessment methods (the development measure method) in the processes of multi-variant design of technical and organizational solutions on the example of selecting equipment for a newly designed mine working in a hard coal mine. Using the case study, the authors proposed an alternative solution for decision-making problems in mining companies in relation to solutions based solely on unit costs of coal mining. The case study is preceded by the presentation of general principles regarding cost accounting in mining companies as well as the use of multi-criteria assessments.

14

Sorption of saturated and unsaturated hydrocarbons on selected coal sample from the Pniówek mine

80%

Baran P. , Cygankiewicz J. , Krzyżanowski A. , Zarębska K.

Geology, Geophysics and Environment

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2013

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tom Vol. 39, no. 4

341--349

EN

Type, amount and composition of gases which form in rocks and coals during a metamorphism process depend on a number of factors in particular genetic type of original matter, way and conditions of its gathering, temperature, pressure and geological time. Sorption tests were done by the volumetric method, with the use of adsorption micro-burettes. A major advantage of the measurement set-up is that the surplus amounts of adsorbate can be used in experiments, which is of particular importance when handling sorbents with heterogeneous structure, such as hard coals. Sorbates used in the test program were the vapours of hexane, hex-1-ene, heptane, hept-1-ene, octane and benzene. Measurement results seem to corroborate the hypothesis that sorption of polar substance vapours is chiefly a surface process. Polarity of hard coals, mostly associated with the presence of reactive oxygen groups (nitrogen and sulphuric groups), largely affects the sorption of polar substances and in a most characteristic manner controls the sorption of apolar ones. In the case of the latter, sorption is induced by the action of the dispersive interaction force between the coal surface and the sorbate's polar molecules. The pattern of sorption isotherms indicates that the presence of dual bond affects the sorbent-sorbate interactions and hence the sorption capacity of investigated coals.

15

Modelling of coal particle combustion in fluidized bed

80%

Pelka P.

Archivum Combustionis

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2015

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tom Vol. 35 nr 2

65--74

EN

In the article the analysis of issues of modelling of coal particle combustion in a fluidized bed was carried out. Moreover, the results of the validation of a new proposition of a mathematical model of single char particle combustion in a fluidized bed were presented in the paper. This model takes account of the mass loss resulting from the contact of the bed particle with the surface of a burning char particle. In the opinion of many authors, the contact of inert material with a char particle causes their fragmentation which in some conditions of combustion and hydrodynamics of bed leads to the elutriation of unburnt fine particles from the combustion chamber increasing the incomplete loss of combustion. During the model validation the mechanical coal properties i.e. Vickers hardness and fracture toughness were taken into account as presented in [2]. The wide range of experimental tests, on which basis of which the model validation allowed the determination of the possibility of the model application to predict a combustion rate in fluidized bed conditions, as well as the contribution of the erosion process to the total mass loss. It also indicated that the main reason for combustion intensification in the fluidized bed is the clearance (elimination) of ash from the surface of the burning char and the increase of mass transfer coefficient in the particle region.

16

Utilization of coal in the Czech Republic

80%

Roubicek V. , Kolat P.

Karbo

|

1999

|

tom Nr 8-9

295-298

EN

The annual output in the volume of 21 mIn tonnes of hard coal and 60 mIn tonnes of brown coal can be maintained for many years. The attention is brought to improvement of economics of coal mining industry, utilisatioin of coal and upgrading of the environment. The introduction of modern technologies is limited by investment possibilities. The artic presents numerical infomation on technological solutions.

PL

Produkcja roczna w wysokości 21 mln ton węgla kamiennego i 60 mln ton węgla brunatnego może być utrzymana przez wiele lat. Uwaga koncentruje się na poprawie ekonomiki górnictwa i użytkowania węgla oraz poprawie ochrony środowiska. Wprowadzenie nowoczesnych technologii jest limitowane możliwościami inwestycyjnymi. Przedstawiono informacje liczbowe dotyczące rozwiązań technologicznych.

17

Studies of catalytic coal gasification with steam

80%

Porada S. , Rozwadowski A. , Zubek K.

Polish Journal of Chemical Technology

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2016

|

tom Vol. 18, nr 3

97--102

EN

One of the promising processes, belonging to the so-called clean coal technologies, is catalytic coal gasification. The addition of a catalyst results in an increased process rate, in which synthesis gas is obtained. Therefore, the subject of this research was catalytic gasification of low-ranking coal which, due to a high reactivity, meets the requirements for fuels used in the gasification process. Potassium and calcium cations in an amount of 0.85, 1.7 and 3.4% by weight were used as catalytically active substances. Isothermal measurements were performed at 900°C under a pressure of 2 MPa using steam as a gasifying agent. On the basis of kinetic curves, the performance of main gasification products as well as carbon conversion degree were determined. The performed measurements allowed the determination of the type and amount of catalyst that ensure the most efficient gasification process of the coal ‘Piast’ in an atmosphere of steam.

18

Prognosticating fire hazards in goafs in Polish collieries

80%

Zarębska K. , Baran P. , Cygankiewicz J. , Dudzińska A.

AGH Drilling, Oil, Gas

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2012

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tom Vol. 29, no. 4

463--478

EN

The purpose of the study is to determine the sorption capacity of hard coals from Polish collieries with respect to several sorbets: ethane, ethylene, propane, propylene. The knowledge of the sorption capacity of coal with respect to a wide range of sorbates is essential to ensure the miners' safety and to allow for reliable forecasting fire hazard and self-heating of coal. The self-heating process is evaluated using specialist indicators based on hydrocarbon contents in mine air. Coal properties, such as porosity, coal rank, maceral content, moisture, ash and volatile matter contents as well as proportion of mineral substances are of key importance for understanding the processes taking place on the hard coal-gas interface. The quantitative analysis of these parameters supported by sorption tests will provide us information about the coal's structure's tendency to accumulate and release gases and vapours. It is important to determine the accessibility of the internal coal structure to gases and to investigate the influence of the micro- and submicro-porosity on the process of sorption. Concentrations of non-saturated hydrocarbons: ethylene and propylene are good indicators used to evaluate the scale of the self-heating process. Therefore, we need to reliably establish whether hydrocarbons present in mine air are released only through the self-heating process or whether they can be also accumulated in the coal structure and then desorbed when the conditions should change. Although preventive measures have been put place in Polish collieries, endogenous fire are still fairly frequent, so the hazard control based only on concentrations of non-saturated hydrocarbons may prove insufficient. It is also necessary to determine whether those hydrocarbons can be accumulated in coal, what factors will trigger this process and in what extent. Results of such tests will contribute to fire prevention and will help control other hazards associated with underground mining operations.

19

Main trends of development of clean coal technologies in Ukraine

80%

Pivnyak G. G. , Rogoza M. V.

Gospodarka Surowcami Mineralnymi

|

2006

|

tom T. 22, z. 2

5-13

EN

Taking into consideration the level of world economic development the analysis of contemporary world tendencies of fuel and power resources production and consumption is presented. The role of coal in electric powermindustry of Europe and Ukraine is shown. The results of establishment of innovative mining machines and mechanisms in Ukraine (mining mechanized complexes, winning and heading combines, transport equipment etc.) are laid down. The issues of the most effective using coal energetic capacity and complex exploitation of coal deposits for chemical industry including motor oil production are considered. Taking into account contemporary world tendencies and environmental aspects the substantiation of ways and technical decisions that allow the Ukraine avoid ineffective using natural gas in power industry is presented.

PL

W artykule przedstawiono analizę globalnych pierwotnych nośników energii, ich zasoby, produkcję i zużycie. Na tym tle omówiono rolę węgla do produkcji energii elektrycznej w Europie, jak również na Ukrainie. Szczególną uwagę zwrócono na sytuację w górnictwie węglowym Ukrainy. Wskazano na możliwości zastosowania węgla do produkcji paliw płynnych, mając na uwadze ochronę środowiska przyrodniczego w energetyce, przedstawiono możliwości zamiany węgla na gaz ziemny przy wytwarzaniu energii elektrycznej.

20

Wzbogacanie węgla kamiennego w polskich zakładach przeróbczych

80%

Szulik W.

Ochrona Powietrza i Problemy Odpadów

|

2007

|

tom Vol. 41 nr 6

176-181

PL

Przedstawiono przegląd technologii wzbogacania węgla, jakie stosowane są w zakładach przeróbczych w Polsce. Omówiono potrzebę wzbogacania węgla kamiennego w aspekcie ochrony środowiska. Wskazano, jaki rodzaj domieszek stanowi zbędny balast w węglu surowym, który podczas spalania jest źródłem tworzenia się zanieczyszczeń powietrza. Przedstawiono charakterystykę każdego z etapów wzbogacania węgla w całym zakresie ziarnowym.

EN

A review of technologies used for coal enrichment plants in Poland is presented. The need of coal enrichment is discussed in the aspect of environmental protection. Types of admixtures which are useless ballast in raw coal were indicated as a source of the air pollution in the coal combustion processes. The profiles of individual enrichment stages in the complete range of the coal grain-size were presented.