Tehno-ekonomska analiza centraliziranog toplinskog sustava baziranog na geotermalnoj energiji

undergraduate thesis

• Title (english): Techno-economic analysis of a geothermal district heating system
• Author: Luka Herc
• Mentor: Neven Duić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2019-03-01, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

Geotermalna energija je idealna tehnologija za povećanje udjela obnovljivih izvora u proizvodnji električne i toplinske energije. Povijesno je bila ograničena na geološki aktivnija područja, ali se napretkom prvenstveno ORC tehnologije ostvaruje mogućnost primjene na izvorima s relativno niskom temperaturom termalne vode. Korištenje geotermalne energije u svrhu grijanja sve više postaje mogućnost čak i kod izvora s niskim temperaturama. Nove energetski visokoučinkovite zgrade ne zahtijevaju visoke temperature u sustavu grijanja pa se toplinske potrebe mogu zadovoljiti i iz niskotemperaturnih izvora. Ukoliko zgrade nisu niskoenergetske ili je kombinacija zgrada raznih energetskih karakteristika što je i najčešći slučaj, postoji mogućnost korištenja geotermalnih dizalica topline samostalno ili u kombinaciji s nekom drugom tehnologijom. U sklopu ovog rada su razmatrana moguća tehnička rješenja primjene geotermalne energije u svrhu proizvodnje električne i toplinske energije. Razmatrane su dvije lokacije (Rečica i Lanište) i za svaku je izrađeno nekoliko tehničkih rješenja. Prikazuje se proračun CTS-a i njegovih komponenata te geotermalnog binarnog ORC-a. Određivanje toplinskog opterećenja je provedeno stupanj – sat metodom, a radna karakteristika svake komponente sustava je modelirana pripadajućom funkcijom. Kako bi se odredila najbolja kombinacija instaliranih snaga pojedinih komponenata, provedena je tehno – ekonomska analiza. Za slučaj lokacije „Rečica“ su napravljene 4 varijante korištenja izvora: izgradnja binarnog ORC postrojenja i CTS-a u obližnjim naseljima, izgradnja binarnog ORC postrojenja i spoja na CTS grada Karlovca, samo opskrba CTS-a u Karlovcu te izgradnja samo ORC postrojenja. Na lokaciji „Lanište“ je napravljeno također 4 varijanta: izgradnja novog CTS-a i opskrba putem geotermalne dizalice topline, kombinacija geotermalne dizalice topline i kotla s električnim grijačem, kombinacija geotermalne dizalice topline i kotla na prirodni plin, kombinacija geotermalne dizalice topline i kotla na biomasu. Na lokaciji „Rečica“ su svi scenariji s izuzetkom scenarija izgradnje ORC-a i novog CTS-a u naseljima Rečica i Luka Pokupska profitabilni s unutarnjim stopama povrata iznad 20 %. Najprofitabilniji je scenarij izgradnje geotermalnog ORC postrojenja. Scenariji razmatrani na lokaciji Lanište nisu isplativi unutar 15 godina te je potrebno uložiti nepovratna sredstva ili povećati cijenu toplinske energije. Najbolji od projekata na toj lokaciji je kombinacija geotermalne dizalice topline koja radi u baznom opterećenju te kotla na prirodni plin koji pokriva vršna opterećenja.

Abstract (english)

Geothermal energy is reliable renewable energy source. It has historically been limited to usage only on geologically active locations, but with the advancements in ORC technology, it has become viable to use relatively low temperature heat sources. New highly energy efficient buildings do not require high water temperature in their heating systems. Therefore, it is possible to use lower temperature heat sources. The most common case when designing district heating network is combination of buildings with differing thermal properties. In that case, additional heat source may be required to provide desired temperature of heating water. This can be geothermal heat pump standalone or in combination with electric heater, natural gas boiler or biomass boiler. In this thesis, two possible locations (Rečica and Lanište) were analyzed for usage of geothermal energy in electricity and heat generation. Few technical solutions were made for each of them. This thesis describes the procedure of designing DH network with all of its components and geothermal binary ORC. Yearly heat load distributions were made by using the degree – hour method. Each component of the facility is described with mathematical function. For each scenario techno – economic analysis has been made. It shows which scenario is better and worth investing and also enables comparison between various scenarios. At the site “Rečica”, four scenarios were made: use of geothermal energy solely for electricity generation with ORC, combination of ORC and new district heating system in nearby towns Rečica and Luka Pokupska, combination of electricity generation in ORC and supply of existing district heating system in Karlovac City and only supply of DH in Karlovac. Four scenarios were also made for the second location, “Lanište”: New district heating system based on geothermal heat pump, on combination of geothermal heat pump and electric heater, combination with the natural gas boiler and combination with biomass boiler. All of the scenarios at the site “Rečica” with exception of new ORC and DH in Rečica and Luka Pokupska are profitable with internal return rate above 20 %. The most profitable scenario is the one which includes electricity generation in geothermal ORC facility. At the site “Lanište”, none of the scenarios are profitable within 15 years. However, they can be made profitable with the application for EU funding or by increasing heat prices. The best scenario at this site is combination of geothermal heat pump for covering the base load with natural gas boiler for peak demand.

• Keywords: ORC; Organski Rankineov ciklus; Binarni ORC; geotermalna energija; centralizirani toplinski sustav; obnovljivi izvori energije; dizalica topline; prirodni plin; biomasa; kotao
• Keywords (english): ORC; Organic Rankine cycle; binary ORC; geothermal energy; district heating; electricity generation; renewable energy sources; heat pump; natural gas; biomass; boiler
• Language: croatian
• URN:NBN: urn:nbn:hr:235:999490
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-23 00:07:40