Iskanje po katalogu digitalne knjižnice

Opis: Zbirka rešenih vaj predstavlja dodatno učno gradivo z rešenimi nalogami pri predmetu Tehnološko modeliranje energetskih procesov, ki je namenjeno predvsem študentom magistrskega študija na Fakulteti za energetiko Univerze v Mariboru. Gradivo zajema tri ključna poglavja, ki jih je v okviru predmeta potrebno razumeti in znati samostojno rešiti. Prvo poglavje predstavlja poenostavljanje bločnih diagramov, kjer je s pomočjo pravil algebre na primerih prikazan postopek poenostavljanja po posameznih korakih. Drugo poglavje zajema predstavitev bločnega diagrama iz diferencialne enačbe, kjer je iz pripadajoče diferencialne enačbe prikazana pretvorba v bločni diagram. Zadnje poglavje zajema metode za numerično reševanje diferencialnih enačb, kjer je na primeru diferencialne enačbe pri podanem začetnem pogoju s celotnim postopkom prestavljen izračun po analitični in Eulerjevi metodi ter metodi Runge Kutta 2. in 4. reda.
Ključne besede: bločni diagram, diferencialna enačba, numerično reševanje diferencialnih enačb, analitična metoda, Eulerjeva metoda, Runge Kutta 2. in 4. reda
Objavljeno v DKUM: 25.04.2022; Ogledov: 877; Prenosov: 87
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Opis: Zbirka laboratorijskih vaj je primarno namenjena študentom 1.letnika magistrskega študijskega programa na Fakulteti za energetiko Univerze v Mariboru, in sicer kot dodatno učno gradivo pri izvajanju laboratorijskih vaj v okviru učne enote Tehnološko modeliranje energetskih procesov. Kot taka se tudi direktno vsebinsko navezuje na pripadajoče računalniške vaje. Vaje so namenjene eksperimentiranju z različnimi sistemi oz. procesi, modeliranju in vrednotenju matematičnih modelov. Študentje na takšen način izboljšajo poznavanje in razumevanje mehanizmov delovanja obravnavanih procesov ter skozi praktično delo spoznajo celoten cikličen postopek modeliranja, ki vključuje izvedbo meritev, kot tudi izdelavo in uporabo matematičnih modelov. Zbirka laboratorijskih vaj v povezavi z računalniškimi vajami in predavanji povezuje obravnavano tematiko v zaključeno celoto.
Ključne besede: laboratorijske vaje, meritve, modeliranje, dinamični sistemi, elektromehanski sistemi
Objavljeno v DKUM: 25.04.2022; Ogledov: 817; Prenosov: 43
Celotno besedilo (3,91 MB)
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Opis: A dredging process is essential for the development of harbours and ports, allowing the functional daily operation of the port. The management of dredged material represents a worldwide challenge, especially considering unwanted deposition of material. Because of their chemical, petrographic, mineralogical and homogeneity composition, marine sediments could represent an appropriate raw material for the brick industry, particularly for the production of clay blocks, roofing and ceramic tiles. In this study dredged material from Port of Koper was tested for such use, thus various analyses were carried out in order to determine if the dredged material is environmentally friendly and suitable for use in the brick industry. These included: chemical analysis, mineralogical analysis, particle size analysis, chloride content analysis and tests of firing in a gradient furnace. Furthermore, tests of mechanical properties, as well as tests of the frost-resistance of the samples were carried out. On the basis of the primary analyses and samples prepared in a laboratory, it was confirmed that marine sediments from the Port of Koper, without any additives are only conditionally suitable as a source material for producing brick products, because without additives they exhibit too much shrinkage on drying and firing, as well as high water absorption, this can be improved by the incorporation of suitable additives, for example, virgin clay or other suitable waste material. The approach described herewith can also be followed to assess sediments from other ports and rivers regarding its potential use in clay brick sector.
Ključne besede: dredge marine sediment, recycling, clay bricks, mechanical properties, chemical analysis
Objavljeno v DKUM: 21.12.2017; Ogledov: 2107; Prenosov: 171
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Opis: Underground coal gasification (UCG) is a viable possibility for the exploitation of vast coal deposits that are unreachable by conventional mining and can meet the energy, economic and environmental demands of the 21st century. Due to the complexity of the process, and the site-specific coal and seam properties, it is important to acknowledge all the available data and past experiences, in order to conduct a successful UCG operation. Slovenia has huge unmined reserves of coal, and therefore offers the possibility of an alternative use of this domestic primary energy source. According to the available underground coal gasification technology, the energy and economic assessment for the exploitation of coal to generate electricity and heat was made. A new procedure for the estimation of the energy efficiency of the coal gasification process, which is also used to compare the energy analyses for different examples of coal exploitation, was proposed, as well as the technological schemes and plant operating mode in Velenje, and the use of produced synthetic coal gas (syngas). The proposed location for the pilot demonstration experiment in Velenje Coal Mine was reviewed and the viability of the underground coal gasification project in Velenje was determined.
Ključne besede: underground coal gasification, syngas, clean coal technology, energy analysis, economic analysis
Objavljeno v DKUM: 31.08.2017; Ogledov: 2509; Prenosov: 376
Celotno besedilo (1,32 MB)
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Opis: The exergy analysis of a Brayton cycle is performed in the paper. The four input variables: the ratio of the compressor exit and inlet pressures, the ratio of inlet temperature of gases in turbine and inlet temperature of air in compressor and the isentropic efficiencies of the compressor and turbine are analysed. The temperature ratio is varied in a way that the compressor inlet temperature of air is maintained constant, while the turbine inlet temperature of flue gases is varied from 900 to 1200°C. In the combustion chamber methane is completely combusted with excess air ratio which is determined by the temperature of flue gases at the turbine inlet. The analysis further includes variability of the molar heat capacities of air and flue gases with temperature and variability of their heat capacity ratios. The exergy destruction in turbine, compressor and combustion chamber and also total exergy efficiency of the cycle are considered in the analysis.
Ključne besede: Brayton cycle, variable physical properties, variable composition of working substance, maximum work output, maximum thermal efficiency
Objavljeno v DKUM: 12.07.2017; Ogledov: 1885; Prenosov: 325
Celotno besedilo (789,62 KB)
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