Optimizacija zgorevanja v potisni peči s kisikom obogatenim zrakom : magistrsko delo

Bobnar, Matic (avtor), Kosec, Borut (mentor)

Jeklene slabe moramo pred procesom vročega valjanja ogreti v potisni peči na temperaturo preoblikovanja, kar je drag in energetsko potraten proces. Potisna peč v naši vroči valjarni predstavlja ozko grlo, zato smo z idejo, da bi povečali produktivnost peči, naredili model na osnovi računalniške dinamike tekočin (angleško computational fluid dynamics ali na kratko CFD), s katerim smo izračunali parametre, ki so za nas ključnega pomena, pri tem pa bi spreminjali vrsto goriva, ter delež kisika v zraku. Ti parametri so: temperatura plamena, emisije CO2, NOx ter delež saj. V magistrskem delu so bile narejene tri simulacije za vsako vrsto goriva. Kot prvo gorivo smo vzeli zemeljski plin, naš trenuten energent v potisni peči. Kot potencialno substitucijsko gorivo, smo vzeli propan, namreč sta cena in dobava zemeljskega plina v trenutni geopolitični situaciji vprašljiva. Kot drugo substitucijsko gorivo, pa smo vzeli vodik, namreč vodik predstavlja zeleno gorivo prihodnosti. Drug parameter, ki smo ga pa spreminjali, pa je bil delež kisika v zgorevalnem zraku. Prva prevzeta vrednost je bila 21%, torej atmosferska vrednost, druga prevzeta vrednost je bila 23% in tretja 25%. Iz rezultatov simulacij, smo glede na temperaturo plamena, preko toplotnotehničnih izračunov določili novo zmogljivost peči. Preko preračunane zmogljivosti peči, pa smo lahko tudi vrednotili emisije CO2, NOx in delež saj na tono. Nato smo naredili primerjavo emisij glede na sedanjo stanje in ocenili, ali je zgorevanje s povišanim deležem kisika v zraku ekološki proces. Za konec smo pa preko cene jekla na trgu, ter tržne cene tehnično čistega kisika naredili finančno bilanco, ali je zgorevanje s povišanim deležem kisika v zraku, tudi ekonomično rentabilen proces.

• Jezik: Slovenski jezik
• Ključne besede: jeklo, emisije, potisna peč, računalniška dinamika tekočin, optimizacija zgorevanja
• Vrsta gradiva: Magistrsko delo/naloga
• Tipologija: 2.09 - Magistrsko delo
• Organizacija: NTF - Naravoslovnotehniška fakulteta
• Kraj izida: Ljubljana
• Založnik: M. Bobnar
• Leto izida: 2024
• Št. strani: XIII, 49 f.
• PID: 20.500.12556/RUL-155928
• UDK: 669
• COBISS.SI-ID: 193684739
• Datum objave v RUL: 24.04.2024

BOBNAR, Matic, 2024, Optimizacija zgorevanja v potisni peči s kisikom obogatenim zrakom : magistrsko delo [na spletu]. Magistrsko delo. Ljubljana : M. Bobnar. [Dostopano 26 junij 2025]. Pridobljeno s: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=slv&id=155928

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Optimisation of burning in pusher type furnace with oxygen enriched air : master's thesis

Izvleček

We need to preheat the steel slabs before the hot rolling process in the pusher type furnace to the temperature suitable for hot rolling, which is an expensive and energy consuming process. The pusher type furnace in our hot rolling mill represents a bottleneck, so with the idea of increasing furnace productivity, we have created a model based on computational fluid dynamics (CFD), with which we have calculated parameters crucial to us, while varying the type of fuel and the oxygen content in the air. These parameters include flame temperature, CO2 emissions, NOx emissions and soot content. In the master’s thesis three simulations were performed for each type of fuel. Firstly we used natural gas as the fuel, which is also our current energy source in the pusher type furnace. As a potential substitute, we have considered propane, as the price and supply of natural gas is questionable in current geopolitical situation. As second substitute fuel, we chose hydrogen, as hydrogen represents the green fuel of the future. The other parameter which we were varying was the oxygen content in the combustion air. First assumed value was 21 %, which is atmospheric value. Second assumed value was 23 % and the third was 25 %. From the simulation results, we determined the new furnace capacity based on flame temperature through thermotehnical calculations. Using the calculated furnace capacity, we could also evaluate CO2 emissions, NOx emissions and soot content per ton. Then we compared emissions with the current state and assessed whether combustion with an increased oxygen content in the air is an environmentally friendly process. Finally, we conducted a financial evaluation by comparing the market price of still and the market price of technically pure oxygen to determine whether combustion with an increased oxygen content in the air is also economically viable.

• Ključne besede: steel, emissions, pusher type furnace, computational fluid dynamics, optimisation of burning