Energetska analiza punjenja i pražnjenja pozemnog skladišta prirodnog plina

master's thesis

• Title (english): Energy analysis of filling and emptying of underground natural gas storage
• Author: Tomislav Zelenika
• Mentor: Mislav Čehil (mentor)
• Committee member: Vladimir Soldo (predsjednik povjerenstva)
• Committee member: Igor Balen (član povjerenstva)
• Committee member: Mislav Čehil (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2021-12-17, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

Zbog svojeg manje štetnog utjecaja na okoliš u odnosu na ugljen i naftu, te određenih političkih i društvenih čimbenika, očekuje se rast potražnje za plinom u nadolazećim godinama. U toj potražnji za plinom javljaju se oscilacije zbog različitih klimatskih uvjeta zimi i ljeti te načina života ljudi. Stoga je razumno koristiti objekte poput skladišta plina, pomoću kojih se mogu pokrivati dnevne i sezonske fluktuacije u potražnji. Skladišta mogu biti nadzemna i podzemna. U ovome radu promatra se projekt vršnog podzemnog skladišta ''Grubišno Polje'', čija je izgradnja u tijeku. Na istoimenom eksploatacijom polju, dvije istražne bušotine su dale pozitivan rezultat o postojanju prirodnoga plin. Taj će se plin, u prvoj fazi projekta, djelomično iscrpiti i komprimirati u plinski transportni sustav Republike Hrvatske. Nakon iscrpljivanja, djelomično iscrpljeno ležište će se koristiti za privremeno spremanje plina iz sustava. Za procese početnog crpljenja plina te njegovog utiskivanja, koristi se kompresor pogonjen plinskim motorom. Radni volumen ležišta biti će oko 100 milijuna m3, a odlikovati će ga relativno veliki kapaciteti utiskivanja i povlačenja plina, što će omogućiti pokrivanje vršnih opterećenja u sustavu i sigurnost opskrbe plinom na području Republike Hrvatske. U sklopu matematičkog modela opisati će se najprije faza crpljenja ležišnog plina, a nakon toga i proces utiskivanja plina iz magistralnog plinovoda u ležište, s čime započinje faza skladištenja plina. U modelu se opisuju i pojave u kompresoru, što omogućuje određivanje ovisnosti potrebne snage plinskog motora o napunjenosti spremnika. Također, u sklopu matematičkog modela dana je usporedba rada skladišta kroz dva scenarija sa različitim razinama napunjenosti spremnika. Kada je razina napunjenosti spremnika visoka, tlak plina također doseže visoke vrijednosti pa povlačenje takvog plina znači energetski gubitak. Razlog za gubitak je u tome što se plin visokoga tlaka ne smije pustiti u plinovod čiji je tlak znatno niži, te je potrebno napraviti njegovu redukciju. Također, potrebna je veća snaga plinskog motora da bi se plin utiskivao u spremnik čija je razina napunjenosti visoka.

Abstract (english)

Due to its less harmful impact on the environment compared to coal and oil, and certain political and social factors, the demand for gas is expected to grow in the coming years. In gas demand, oscillations occur due to different climatic conditions in winter and summer and also people's way of life. Therefore, it is reasonable to use facilities such as gas storage facilities, which can cover daily and seasonal fluctuations in demand. Storages can be aboveground and underground. In this paper, the project of the peak underground gas storage "Grubišno Polje" is observed, the construction of which is in progress. In the Grubišno Polje field, two exploration wells gave a positive result on the existence of natural gas. In the first phase of the project, this gas will be partially depleted and compressed into the gas transport system of the Republic of Croatia. After depletion phase, the partially depleted reservoir will be used to temporarily store gas from the system. For the processes of initial gas extraction and its injection, a compressor driven by a gas engine is used. The working volume of the reservoir will be about 100 million m3, and it will be characterized by relatively large capacities of gas injection and withdrawal, which will cover the peak loads in the system and security of gas supply in the Republic of Croatia. The mathematical model will first describe the phase of extraction of gas, and then the process of injecting gas from the main gas pipeline into the reservoir, which begins the phase of gas storage. The model also describes the phenomena in the compressor, which allows to determine the dependence of the required power of the gas engine on the filling of the tank. Also, as part of the mathematical model, a comparison of storage operation is given through two scenarios with different levels of tank filling. When the tank filling level is high, the gas pressure also reaches high values, so withdrawing such gas means energy loss. The reason for the loss is that high-pressure gas must not be allowed into a gas pipeline whose pressure is significantly lower, and it is necessary to reduce it. Also, more gas engine power is required to inject gas into a tank whose charge level is high.

• Keywords: plin; ležište; podzemno skladište plina; kapacitet utiskivanja; kapacitet povlačenja; tlak; temperatura; kompresor; plinski motor; Grubišno Polje
• Keywords (english): gas; well; underground gas storage; injection capacity; deliverability; pressure; temperature; compressor; gas engine; Grubišno Polje
• Language: croatian
• URN:NBN: urn:nbn:hr:235:114382
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-12-08 10:53:44