Energy analysis of the cascade use of geothermal water in the greenhouse production at the Lunjkovec - Kutnjak field : master's thesis

Ulaskom u Europsku uniju, Republika Hrvatska preuzela je obvezu ispunjenja određenih energetskih ciljeva između kojih su i smanjenje stakleničkih plinova te poboljšanje gospodarskih prilika korištenjem obnovljivih izvora energije. Prva konkretna realizacija navedenih ciljeva je puštanje u rad prve geotermalne elektrane Velika Ciglena. Jedna od gospodarskih mogućnosti koje se mogu poboljšati uz iskorištavanje obnovljivih izvora energije je opskrba poljoprivrednih gospodarstava toplinskom energijom povoljne prodajne cijene budući da se veliki udio BDP-a Hrvatske temelji na poljoprivredi. Na temelju karakteristika istražnog lokaliteta Lunjkovec – Kutnjak i planiranog projekta izgradnje elektrane i proizvodnje i distribucije transformiranih oblika energije iz geotermalne energije izrađen je dinamički model iskorištavanja geotermalne energije. Geotermalna energija bi se iskorištavala za grijanje staklenika čije su toplinske potrebe određene na temelju vanjskih temperatura zraka u vremenskom periodu od 1999. do 2013. godine. Grijanje staklenika izvedeno je putem dva termotehnička rješenja: sustava direktnog iskorištavanja geotermalne energije koristeći ventilokonvektore i kaskadnog hibridnog sustava gdje se nakon direktnog iskorištavanja geotermalne vode protok usmjerava na sljedeći sustav direktnog iskorištavanja ventilokonvektorima ili na dizalice topline, ovisno o temperaturi geotermalne vode.By joining the European Union, the Republic of Croatia has undertaken the obligation to fulfill certain energy goals, which include reducing greenhouse gases and improving economic opportunities through the use of renewable energy sources. The first concrete realization of these goals is the commissioning of the first geothermal power plant at Velika Ciglena. One of the economic opportunities that can be improved with the use of renewable energy sources is the supply of farms and greenhouses with heat energy at a reasonable selling price, since a large share of Croatia's GDP is based on agriculture. Based on the characteristics of the Lunjkovec - Kutnjak geothermal field and the planned project for the construction of a geothermal power plant as well as the production and distribution of transformed forms of energy from geothermal energy, a dynamic model of utilization of geothermal energy from the waste heat of geothermal water was created. Geothermal energy could be used to heat greenhouses whose heat needs were determined based on outdoor air temperatures from 1999 to 2013. Greenhouse heating was performed through two thermo-technical solutions: a system of direct use of geothermal energy using a fan coil and a cascade hybrid system where, after the direct use of geothermal water, the flow is directed towards fan-coils or heat pumps, depending on the temperature of geothermal water

Energy analysis of the cascade use of geothermal water in the greenhouse production at the Lunjkovec - Kutnjak field : master's thesis

Ulaskom u Europsku uniju, Republika Hrvatska preuzela je obvezu ispunjenja određenih energetskih ciljeva između kojih su i smanjenje stakleničkih plinova te poboljšanje gospodarskih prilika korištenjem obnovljivih izvora energije. Prva konkretna realizacija navedenih ciljeva je puštanje u rad prve geotermalne elektrane Velika Ciglena. Jedna od gospodarskih mogućnosti koje se mogu poboljšati uz iskorištavanje obnovljivih izvora energije je opskrba poljoprivrednih gospodarstava toplinskom energijom povoljne prodajne cijene budući da se veliki udio BDP-a Hrvatske temelji na poljoprivredi. Na temelju karakteristika istražnog lokaliteta Lunjkovec – Kutnjak i planiranog projekta izgradnje elektrane i proizvodnje i distribucije transformiranih oblika energije iz geotermalne energije izrađen je dinamički model iskorištavanja geotermalne energije. Geotermalna energija bi se iskorištavala za grijanje staklenika čije su toplinske potrebe određene na temelju vanjskih temperatura zraka u vremenskom periodu od 1999. do 2013. godine. Grijanje staklenika izvedeno je putem dva termotehnička rješenja: sustava direktnog iskorištavanja geotermalne energije koristeći ventilokonvektore i kaskadnog hibridnog sustava gdje se nakon direktnog iskorištavanja geotermalne vode protok usmjerava na sljedeći sustav direktnog iskorištavanja ventilokonvektorima ili na dizalice topline, ovisno o temperaturi geotermalne vode.By joining the European Union, the Republic of Croatia has undertaken the obligation to fulfill certain energy goals, which include reducing greenhouse gases and improving economic opportunities through the use of renewable energy sources. The first concrete realization of these goals is the commissioning of the first geothermal power plant at Velika Ciglena. One of the economic opportunities that can be improved with the use of renewable energy sources is the supply of farms and greenhouses with heat energy at a reasonable selling price, since a large share of Croatia's GDP is based on agriculture. Based on the characteristics of the Lunjkovec - Kutnjak geothermal field and the planned project for the construction of a geothermal power plant as well as the production and distribution of transformed forms of energy from geothermal energy, a dynamic model of utilization of geothermal energy from the waste heat of geothermal water was created. Geothermal energy could be used to heat greenhouses whose heat needs were determined based on outdoor air temperatures from 1999 to 2013. Greenhouse heating was performed through two thermo-technical solutions: a system of direct use of geothermal energy using a fan coil and a cascade hybrid system where, after the direct use of geothermal water, the flow is directed towards fan-coils or heat pumps, depending on the temperature of geothermal water

Energy analysis of the cascade use of geothermal water in the greenhouse production at the Lunjkovec - Kutnjak field : master's thesis

Ulaskom u Europsku uniju, Republika Hrvatska preuzela je obvezu ispunjenja određenih energetskih ciljeva između kojih su i smanjenje stakleničkih plinova te poboljšanje gospodarskih prilika korištenjem obnovljivih izvora energije. Prva konkretna realizacija navedenih ciljeva je puštanje u rad prve geotermalne elektrane Velika Ciglena. Jedna od gospodarskih mogućnosti koje se mogu poboljšati uz iskorištavanje obnovljivih izvora energije je opskrba poljoprivrednih gospodarstava toplinskom energijom povoljne prodajne cijene budući da se veliki udio BDP-a Hrvatske temelji na poljoprivredi. Na temelju karakteristika istražnog lokaliteta Lunjkovec – Kutnjak i planiranog projekta izgradnje elektrane i proizvodnje i distribucije transformiranih oblika energije iz geotermalne energije izrađen je dinamički model iskorištavanja geotermalne energije. Geotermalna energija bi se iskorištavala za grijanje staklenika čije su toplinske potrebe određene na temelju vanjskih temperatura zraka u vremenskom periodu od 1999. do 2013. godine. Grijanje staklenika izvedeno je putem dva termotehnička rješenja: sustava direktnog iskorištavanja geotermalne energije koristeći ventilokonvektore i kaskadnog hibridnog sustava gdje se nakon direktnog iskorištavanja geotermalne vode protok usmjerava na sljedeći sustav direktnog iskorištavanja ventilokonvektorima ili na dizalice topline, ovisno o temperaturi geotermalne vode.By joining the European Union, the Republic of Croatia has undertaken the obligation to fulfill certain energy goals, which include reducing greenhouse gases and improving economic opportunities through the use of renewable energy sources. The first concrete realization of these goals is the commissioning of the first geothermal power plant at Velika Ciglena. One of the economic opportunities that can be improved with the use of renewable energy sources is the supply of farms and greenhouses with heat energy at a reasonable selling price, since a large share of Croatia's GDP is based on agriculture. Based on the characteristics of the Lunjkovec - Kutnjak geothermal field and the planned project for the construction of a geothermal power plant as well as the production and distribution of transformed forms of energy from geothermal energy, a dynamic model of utilization of geothermal energy from the waste heat of geothermal water was created. Geothermal energy could be used to heat greenhouses whose heat needs were determined based on outdoor air temperatures from 1999 to 2013. Greenhouse heating was performed through two thermo-technical solutions: a system of direct use of geothermal energy using a fan coil and a cascade hybrid system where, after the direct use of geothermal water, the flow is directed towards fan-coils or heat pumps, depending on the temperature of geothermal water

Two-Stage Geothermal Well Clustering for Oil-to-Water Conversion on Mature Oil Fields

There are numerous oil fields that are approaching the end of their lifetime and that have great geothermal potential considering temperature and water cut. On the other hand, the oil industry is facing challenges due to increasingly stringent environmental regulations. An example of this is the case of France where oil extraction will be forbidden starting from the year 2035. Therefore, some oil companies are considering switching from the oil business to investing in geothermal projects conducted on existing oil wells. The proposed methodology and developed conversions present the evaluation of existing geothermal potentials for each oil field in terms of water temperature and flow rate. An additional important aspect is also the spatial distribution of existing oil wells related to the specific oil field. This paper proposes a two-stage clustering approach for grouping similar wells in terms of their temperature properties. Once grouped on a temperature basis, these clusters should be clustered once more with respect to their spatial arrangement in order to optimize the location of production facilities. The outputs regarding production quantities and economic and environmental aspects will provide insight into the optimal scenario for oil-to-water conversion. The scenarios differ in terms of produced energy and technology used. A case study has been developed where the comparison of overall fields and clustered fields is shown, together with the formed scenarios that can further determine the possible conversion of petroleum assets to a geothermal assets

Investigation of Steady-State Heat Extraction Rates for Different Borehole Heat Exchanger Configurations from the Aspect of Implementation of New TurboCollector™ Pipe System Design

When considering implementation of shallow geothermal energy as a renewable source for heating and cooling of buildings, special care should be taken in the hydraulic design of the borehole heat exchanger system. Laminar flow can occur in pipes due to the usage of glycol mixtures at low temperature or inadequate flow rates. This can lead to lower heat extraction and rejection rates of the exchanger because of higher thermal resistance. Furthermore, by increasing the flow rate to achieve turbulent flow and satisfactory heat transfer rate can lead to an increase in the pressure drop of the system and oversizing of the circulation pump which leads to impairment of the seasonal coefficient of performance at the heat pump. The most frequently used borehole heat exchanger system in Europe is a double-loop pipe system with a smooth inner wall. Lately, development is focused on the implementation of a different configuration as well as with ribbed inner walls which ensures turbulent flow in the system, even at lower flow rates. At a location in Zagreb, standard and extended thermal response tests were conducted on three different heat exchanger configurations in the same geological environment. With a standard TRT test, thermogeological properties of the ground and thermal resistance of the borehole were determined for each smooth or turbulator pipe configuration. On the other hand, extended Steady-State Thermal Response Step Test (TRST) incorporates a series of power steps to determine borehole extraction rates at the defined steady-state heat transfer conditions of 0/−3 °C. When comparing most common exchanger, 2U-loop D32 smooth pipe, with novel 1U-loop D45 ribbed pipe, an increase in heat extraction of 6.5% can be observed. Also, when the same comparison is made with novel 2U-loop D32 ribbed pipe, an increase of 18.7% is achieved. Overall results show that heat exchangers with ribbed inner pipe wall have advantages over classic double-loop smooth pipe designs, in terms of greater steady-state heat extraction rate and more favorable hydraulic conditions

Slagalica nasljeđa : priručnik za opismenjavanje iz medicinske genetike

"Slagalica nasljeđa" - priručnik za opismenjavanje iz medicinske genetike ima tri namjene. Prije svega, on je edukativna slikovnica za studente, liječnike i pacijente, ali i druge zainteresirane pojedince jer su u njoj kroz ilustracije objašnjene osnove genetike čovjeka, kao i osnove medicinske genetike. Od toga kako prepoznati osobu s genetičkim poremećajem, kako nastaju i koje vrste genetičkih poremećaja postoje pa sve do toga na koji ih način možemo dijagnosticirati. Nadalje, nakon svake ilustracije na pojedinoj stranici nalaze se definicije 79 pojmova iz medicinske genetike koje čine tezaurus za studente, liječnike i pacijente koji se na bilo koji način susreću s genetičkim poremećajima. Naposljetku, ova knjiga sadrži i primjere rečenica u koje su ubačeni stručni pojmovi iz medicinske genetike, a koji su namijenjeni studentima prilikom savladavanja komunikacijskih vještina na kolegiju Medicinska genetika, ali i liječnicima prilikom informiranja svojih pacijenata o (mogućem) genetičkom poremećaju. Uz kreatoricu ideje i urednicu izdanja, doc. dr. sc. Ninu Perezu, autori izdanja su studenti šeste godine Integriranog preddiplomskog i diplomskog sveučilišnog studija Medicina i prof. dr. sc. Saša Ostojić

Slagalica nasljeđa : priručnik za opismenjavanje iz medicinske genetike

"Slagalica nasljeđa" - priručnik za opismenjavanje iz medicinske genetike ima tri namjene. Prije svega, on je edukativna slikovnica za studente, liječnike i pacijente, ali i druge zainteresirane pojedince jer su u njoj kroz ilustracije objašnjene osnove genetike čovjeka, kao i osnove medicinske genetike. Od toga kako prepoznati osobu s genetičkim poremećajem, kako nastaju i koje vrste genetičkih poremećaja postoje pa sve do toga na koji ih način možemo dijagnosticirati. Nadalje, nakon svake ilustracije na pojedinoj stranici nalaze se definicije 79 pojmova iz medicinske genetike koje čine tezaurus za studente, liječnike i pacijente koji se na bilo koji način susreću s genetičkim poremećajima. Naposljetku, ova knjiga sadrži i primjere rečenica u koje su ubačeni stručni pojmovi iz medicinske genetike, a koji su namijenjeni studentima prilikom savladavanja komunikacijskih vještina na kolegiju Medicinska genetika, ali i liječnicima prilikom informiranja svojih pacijenata o (mogućem) genetičkom poremećaju. Uz kreatoricu ideje i urednicu izdanja, doc. dr. sc. Ninu Perezu, autori izdanja su studenti šeste godine Integriranog preddiplomskog i diplomskog sveučilišnog studija Medicina i prof. dr. sc. Saša Ostojić