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1.
Opis delovanja spodnjesavske verige hidroelektrarn in nadgradnja pomožne aplikacije za avtomatsko daljinsko vodenje hidroelektrarn z vključitvijo HE Vrhovo : magistrsko delo
Aljaž Prah, 2023, magistrsko delo

Opis: Magistrsko delo se osredotoča na lastnosti in obratovalne značilnosti hidroelektrarn na reki Savi, zlasti na hidroelektrarne na spodnji Savi, ki jih upravlja Center vodenja GEN. Opisana je tudi lastniška organiziranost hidroelektrarn v celotni dolžini reke v Sloveniji. Poleg omejitev obratovanja je hidrologija ključni dejavnik pri načrtovanju proizvodnje hidroelektrarn. Vključitev hidroelektrarne HE Vrhovo v aplikacijo za vodenje je pomembna zaradi njene čelne vloge v verigi hidroelektrarn na spodnji Savi. Z uporabo enoagregatnega modela, ki temelji na preteklih obratovalnih stanjih, je bilo v aplikacijo vključeno obratovanje HE Vrhovo. Nadgradnja aplikacije za avtomatsko daljinsko vodenje hidroelektrarn na spodnji Savi omogoča boljše planiranje in vpogled v dnevno obratovanje hidroelektrarne. Tako lahko dispečerji pripravijo natančen potek obratovanja HE Vrhovo in optimizirajo moč na celotni verigi hidroelektrarn na spodnji Savi. S tem se je povečal finančni izplen celotne verige v času višjih cen električne energije.
Ključne besede: hidroelektrarne, enoagregatni model, optimizacija vodenja
Objavljeno v DKUM: 15.01.2024; Ogledov: 91; Prenosov: 12
.pdf Celotno besedilo (6,03 MB)

2.
Influence of Numerical Mesh Type on Airfoil Aerodynamic Characteristics
Marko Pezdevšek, Matej Fike, Andrej Predin, Gorazd Hren, 2019, objavljeni znanstveni prispevek na konferenci

Opis: In this paper, we will examine how different mesh types affect the aerodynamic characteristic of an airfoil. The airfoil used for this paper was the NREL S809. Three different mesh types were created, a blocked structured mesh, an unstructured mesh and a hybrid mesh containing a blocked structured mesh near the surface of the airfoil and an unstructured mesh on the outside perimeter. Steady state simulations were performed for angles of attack between 0°and 22°. Lift and drag coefficient for all created meshes were compared to experimental results from literature. From angles of attack between 2° and 8° all three meshes predict similar lift and drag coefficients. We encountered problems with convergence for the unstructured mesh at angles of attack higher than 8°. Structured and hybrid mesh had similar lift and drag coefficients across all angles of attack.
Ključne besede: computational fluid dynamics, NREL S809, structured mesh, unstructured mesh, hybrid mesh
Objavljeno v DKUM: 04.12.2023; Ogledov: 154; Prenosov: 9
.pdf Celotno besedilo (18,06 MB)
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3.
Experimental and Numerical Research of Micro Wind Turbine for Low Wind Speeds
Matej Fike, Marko Pezdevšek, Andrej Predin, Gorazd Hren, 2019, objavljeni znanstveni prispevek na konferenci

Opis: In this paper, experimental and numerical study of micro wind turbine for low wind speeds is presented. Numerical simulations were performed for two turbines with different blades at various wind speeds. The first geometry was NTNU turbine and the second was modified NTNU turbine with shorter blades. Results from the numerical study showed that more efficient with higher power coefficient is turbine with modified blades.
Ključne besede: wind turbine, NREL S826, CFD, power coefficient, structured mesh
Objavljeno v DKUM: 04.12.2023; Ogledov: 144; Prenosov: 8
.pdf Celotno besedilo (18,06 MB)
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4.
Lost Energy of Water Spilled over Hydropower Dams
Andrej Predin, Matej Fike, Marko Pezdevšek, Gorazd Hren, 2021, izvirni znanstveni članek

Opis: The present paper presents a view of water spilled over hydropower plants as an energy loss. In the current climate conditions, flood events are becoming more frequent due to human impact on the environment; water spills are also more frequent, which means more and more energy is lost. How much water is spilled and, consequently, how much energy is lost is shown in the present article on the chain of power plants on the Sava River in the five years from 2015 to 2019. An analytical assessment of the current situation in the lock was carried out, which showed that the available water through the locks could be used efficiently. The paper presents a case study of one overflow event lasting 48 h. The calculated theoretical losses of energy (of spilled water) and possible technical implementation for capturing losses are given. The proposed technical implementation is based on established technology, so we could expect that the approach is feasible. The results show that the estimated spilled water energy potential reaches about 40% of the actual spilled water or energy lost.
Ključne besede: energy loss, spilled water energy, hydropower
Objavljeno v DKUM: 13.11.2023; Ogledov: 118; Prenosov: 8
.pdf Celotno besedilo (9,63 MB)
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5.
Energy source replacement in a thermal power plant
Matej Fike, Andrej Predin, 2022, izvirni znanstveni članek

Opis: In Slovenia, approximately one third of electricity is produced in thermal power plants. Electricity prices have risen sharply recently. There are several reasons for this. One of them is the large increase in the price of CO2 coupons that thermal power plants have to buy, since they emit large amounts of greenhouse gas into the environment during the production of electricity. Emissions of the greenhouse gas CO2 are the result of burning fossil fuels, in this case coal. We want to use renewable energy sources to replace fossil fuels and reduce greenhouse gas emissions. More than half of Slovenia is covered with forest, and as a result, wood biomass energy represents a great energy potential. One possibility is the use of wood biomass in a classic thermal power plant for the production of electricity. This contribution presents the energy potential of Slovenian forests, before evaluating the replacement of the energy source in the existing coal-based thermal power plant with wood biomass. It has been discovered that there is enough wood biomass in Slovenia, and that all the electricity that is currently produced from coal can be produced from wood biomass. The cost of wood biomass is higher than the cost of coal. By changing the energy source, we save on the purchase of CO2 coupons. Therefore, the use of wood biomass represents an economically justified energy source for the production of electricity.
Ključne besede: wood biomass, thermal power plant, electricity production
Objavljeno v DKUM: 30.10.2023; Ogledov: 262; Prenosov: 5
.pdf Celotno besedilo (308,95 KB)
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6.
Estimation of real driving emissions based on data from OBD
Matej Fike, Andrej Predin, 2022, objavljeni povzetek znanstvenega prispevka na konferenci

Ključne besede: vehicle, diesel engine, exhaust emission levels, real driving emissions
Objavljeno v DKUM: 30.10.2023; Ogledov: 211; Prenosov: 4
.pdf Celotno besedilo (14,78 MB)
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7.
Energy of water spilled over hydropower dams
Matej Fike, Marko Pezdevšek, Gorazd Hren, Andrej Predin, 2022, objavljeni povzetek znanstvenega prispevka na konferenci

Ključne besede: hydropower, spilled water energy, energy loss, hydropower dams
Objavljeno v DKUM: 30.10.2023; Ogledov: 193; Prenosov: 3
.pdf Celotno besedilo (14,78 MB)
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8.
Numerical prediction of cavitation erosion on a hydrofoil
Marko Pezdevšek, Andrej Predin, Matej Fike, Gorazd Hren, 2022, objavljeni povzetek znanstvenega prispevka na konferenci

Ključne besede: hydrofoil, cavitation, erosion, Ansys CFX
Objavljeno v DKUM: 30.10.2023; Ogledov: 158; Prenosov: 4
.pdf Celotno besedilo (14,78 MB)
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9.
Eksperimentalna, numerična in analitična določitev izkoristka horizontalne vetrne turbine
Andraž Roger, 2021, magistrsko delo

Opis: V magistrskem delu podrobneje pogledamo primerjavo med preračunom z BEM metodo, rezultati pridobljenimi s pomočjo numeričnih simulacij v programu Ansys CFX ter med rezultati meritev karakteristike koeficienta moči v odvisnosti od vrtilne hitrosti trolopatične horizontalne vetrne turbine modelske velikosti s premerom rotorja 640 mm in vetrnim profilom NREL S826, izmerjenih s pomočjo senzorja navora na posebej konstruiranem in izdelanem merilnem mestu. Osredotočili smo se na numerični del, torej na izdelavo modela za numerični preračun, kreiranje numerične mreže ter same simulacije. Kasneje pa še na pripravo in potek eksperimentalnih meritev ter vrednotenje rezultatov meritev. Rezultate bomo prikazali grafično in tabelarično ter jih primerno ovrednotili.
Ključne besede: Meritve, numerične simulacije, CFX, Ansys, ICEM, LDA, BEM
Objavljeno v DKUM: 03.12.2021; Ogledov: 1039; Prenosov: 82
.pdf Celotno besedilo (8,47 MB)

10.
Mala vetrna elektrarna z inovativnim generatorjem: Strategija razvoja in trženje
Lev Mijoč, 2012, diplomsko delo

Opis: V diplomskem delu je predstavljena strategija razvoja male vetrne elektrarne z inovativnim generatorjem kot projekt na ključ. V ta namen smo ovrednotili ekonomski in naravni (vetrni) potencial slovenskega ter evropskega trga za izgradnje malih vetrnih elektrarn, predstavili prednosti inovativnega generatorja v razvoju, izvedli analizo konkurenčnih vetrnih elektrarn v Sloveniji in tujini, pregledali zakonodajo, ki jo je potrebno upoštevati pri projektiranju in izgradnji manjših vetrnih elektrarn v Sloveniji, razčlenili projekte izgradnje za različna naročila izvedb in oblikovali kompleksnost izvedbe ter organizacijo inženiringa. Pripravili smo tudi načrt trženja in izvedli oceno ekonomske upravičenosti projekta za kupca ter za ponudnika vetrnih elektrarn.
Ključne besede: mala vetrna elektrarna, obnovljivi viri energije, inovativni generator, zelena energija, izkoriščanje vetra, izgradnja vetrne elektrarne, učinek strehe, energija vetra, projekt na ključ
Objavljeno v DKUM: 15.03.2021; Ogledov: 945; Prenosov: 79
.pdf Celotno besedilo (4,84 MB)

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