Analiza različitih plinova za primjenu tehnologije podzemnih skladišta energije

master's thesis

• Title: Analiza različitih plinova za primjenu tehnologije podzemnih skladišta energije : diplomski rad
• Title (english): The analysis of application of various gases for the implementation of underground energy storage technologies : master's thesis
• Author: Ivan Bikić
• Mentor: Domagoj Vulin (mentor)
• Mentor: Maja Arnaut (pomoć pri izradi, neposredni voditelj)
• Committee member: Domagoj Vulin (predsjednik povjerenstva)
• Committee member: Luka Perković (član povjerenstva)
• Committee member: Daria Karasalihović Sedlar (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mining, Geology and Petroleum Engineering; (Department of Petroleum and Gas Engineering and energy); Zagreb
• Defense date and country: 2020-01-17, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mining, Petroleum and Geology Engineering; Petroleum Mining

Abstract

Sustavi pohrane energije komprimiranim zrakom (engl. Compressed Air Energy Systems- CAES) primjenjuju se za pohranu viška električne energije u obliku potencijalne energije komprimiranog zraka skladištenog u podzemlju. Osnovne komponente CAES tehnologije čine kompresor, koji koristi višak energije proizveden vjetroelektranama za komprimiranje radnog plina, turbine, koje omogućuju ponovnu pretvorbu u električnu energiju uslijed proizvodnje radnog plina iz ležišta i njegove ekspanzije te podzemno skladište radnog plina. Kao konvencionalni radni plin koristi se zrak, no razmatraju se i drugi plinovi tj. tehnologija se promatra u kontekstu primjene bilo kojeg stlačenog plina u podzemlju (engl. Underground Compressed Gas Energy Storage, UCGES). Osnovni cilj ovog diplomskog rada bio je odrediti mogućnost primjene CO2 kao radnog plina u odnosu na zrak, kao i odrediti mogućnost korištenja dubokih akvifera kao skladišta energije za CAES sustave. Simulacijski slučajevi izrađeni su za ležišta poroznosti 20 % u svrhu određivanja ukupne efikasnosti sustava tijekom utiskivanja i proizvodnje zraka i CO2. CO2 pri uvjetima tlaka od 180·105 Pa i temperature 305,15°K tijekom utiskivanja, te 100·105 Pa tijekom proizvodnje, ima 4,3 puta veću gustoću od zraka što dovodi do mogućnosti proizvodnje veće količine električne energije. Iako je količina proizvedene energije veća u slučaju CO2, ukupna efikasnost sustava, koja je izražena kao omjer proizvedene i utrošene energije je značajno manja nego u slučaju proizvodnje zraka. Ukupna efikasnost sustava tijekom korištenja CO2 ne prelazi 20%, dok efikasnost zraka u svim simulacijskim slučajevima prelazi 50%, iako je ukupno proizvedena električna energija u slučaju zraka značajno manja. Kao mogući razlog manje efikasnosti CO2 su veći maseni protoci tijekom utiskivanja, koji iziskuju veći utrošak energije tijekom komprimiranja.

Abstract (english)

CAES is used for storage of surplus electrical energy produced by wind farms in the form of the potential energy of compressed gas stored underground. Fundamental components of CAES technology are: compressor, which uses surplus electric energy to compress the working gas; turbines, which enable electricity generation by the expansion of the producing gas and underground storage of working gas. Air is used as a conventional working gas for CAES systems, but other gases are also considered, broadening the technology to so called Underground Compressed Gas Energy Storage (UCGES). The main goal of this Master’s thesis is to evaluate the possible application of CO2 as a working fluid. The purpose of all of the simulation cases, in which the total porosity of aquifer was 20 %, was to determine the round trip efficiency of the CAES system during the injection and production cycles of air and CO2. At operating pressure of 180·105 Pa and temperature of 305,15°K during injection, and during the production at of 100·105 Pa, the CO2 has approximately 4,3 times higher density than the air at stated conditions, which leads to higher electricity production, in the case of CO2. Although the generated power is higher for CO2, the round trip efficiency, calculated as the ratio of produced energy and energy used for compression of the gas, is considerably lower than in the case of air. The round trip efficiency of the system in which the CO2 is used as a working gas never exceeds 20 %, while in simulated cases where air was used as a working gas, the efficiency is above 50 %, although the total production of electricity is considerably lower. The possible reason for this phenomenon is higher mass flow rates in the case of CO2 as a working fluid, which requires more energy for the compression of CO2.

• Keywords: CAES; CO2; komprimirani zrak; kompresija; retencija CO2; ekspanzija; stupanj efikasnosti
• Keywords (english): CAES; CO2; air; compression; CO2 retention; expansion; efficiency
• Language: croatian
• URN:NBN: urn:nbn:hr:169:951758
• Study programme: Title: Petroleum engineering; specializations in: Petroleum engineering, Energy production and supply, Environmental protection in petroleum engineering; Course: Petroleum engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka naftnog rudarstva (magistar/magistra inženjer/inženjerka naftnog rudarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-02-21 13:41:08