2024-03-29T16:04:24Z
https://hrcak.srce.hr/ojs/index.php/rgn/oai
oai:ojs.pkp.sfu.ca:article/7423
2018-11-30T16:59:31Z
rgn:SI43
A method to evaluate the impact of urbanization on ground temperature evolution at regional scale
Tinti, Francesco
Kasmaee, Sara
The replacement of natural soil and vegetation by artificial surfaces increases temperatures of the surrounding air and subsurface throughout the year, because of indirect solar heating of urban structures, building heat losses and land use change. This phenomenon is called Urban Heat Island and it can be better perceived during night-time, when the city releases the heat accumulated during the day. During day-time, due to relatively small amounts of solar radiation received by urban surface, especially in high-density cities in arid and semi-arid climates, Urban Cool Island can be identified as well. The present work illustrates a mixed probabilistic-deterministic method to estimate ground temperature at shallow depth, starting from information on geology, hydrogeology, climate, but also urban presence, through correlations with global land cover and population density. A dedicated mapping on regular grid has been produced. Results have been compared with ground and aquifer temperature available in the literature, for some representative cities of Italian Peninsula and Alpine Zone. Preliminary validations are encouraging and can be taken as a starting point for more comprehensive mapping of ground temperature evolution at regional scale.
Faculty of Mining, Geology and Petroleum Engineering
2018-10-10
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Geothermal special issue, December 2018
application/pdf
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7423
10.17794/rgn.2018.5.1
Rudarsko-geološko-naftni zbornik; Vol. 33 No. 5 (2018): No. 43 (special issue)
1849-0409
0353-4529
eng
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7423/4685
Copyright (c) 2018 authors and journal
https://creativecommons.org/licenses/by/4.0
oai:ojs.pkp.sfu.ca:article/7442
2018-11-30T16:59:31Z
rgn:SI43
Heat pump system efficiency comparison of different renewable energy sources – A family house case study in Zagreb city area
Macenić, Marija
Kurevija, Tomislav
Kapuralić, Josipa
Wider Zagreb city area, capital city of Republic of Croatia, has significant potential for major implementation of geothermal heat pump systems in not just the residential sector, but in commercial sector as well. Geothermal heat pumps often cumulatively describes different earth energy heat exchanger installations, from groundwater up to shallow ground horizontal and borehole heat exchangers installations. Zagreb area has especially favourable both hydrogeological and thermogeological parameters, which allows implementation of different designs for residential and commercial heating and cooling. Analysis of comparative energy and economy advantages of heating and cooling with heat pump systems (air, ground or groundwater) was made for capital city of Zagreb. Since heat pump systems in residential area is always higher-class investment, there is often a need for whole year heating since projects increasingly incorporate outside swimming pool. Up till now, many authors investigated comparison of winter heating energy cost for different heat pump systems. However, outdoor swimming pool sometimes consumes as much heating energy during spring-summer-autumn season, as do house in autumn-winter-spring season. Since air temperatures during spring-summer season are much more favourable then sub-cooled ground or groundwater temperatures, air-source heat pumps when used in whole year round for heating, could offset economically unfavourable coefficient of performance (COP) during coldest days of winter. On a real residential home, currently in construction phase, techno-economic analysis was performed comparing seasonal performance factor (SPF) for different heat pump systems during whole year round heating.
Faculty of Mining, Geology and Petroleum Engineering
2018-10-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Geothermal special issue, December 2018
application/pdf
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7442
10.17794/rgn.2018.5.2
Rudarsko-geološko-naftni zbornik; Vol. 33 No. 5 (2018): No. 43 (special issue)
1849-0409
0353-4529
eng
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7442/4686
Copyright (c) 2018 authors and journal
https://creativecommons.org/licenses/by/4.0
oai:ojs.pkp.sfu.ca:article/7502
2018-11-30T16:59:31Z
rgn:SI43
Ground temperature monitoring for a coaxial geothermal heat exchangers field: practical aspects and main issues from the first year of measurements.
Tinti, Francesco
Kasmaee, Sara
Carri, Andrea
Valletta, Alessandro
Segalini, Andrea
Bonduà, Stefano
Bortolotti, Villiam
Ground temperature at shallow depth (< 50 m) is not stable, nor in space, neither in time, and its behaviour is the result of superimposition of effects of heat pulses of different origin: solar, geothermal and anthropic. The correct assessment of ground temperature is a crucial point when designing a shallow geothermal energy system. In geothermal closed loop projects, more the borehole heat exchangers are short, more the contribution of the ground temperature variability on the heat exchange is prominent. Monitoring ground temperature can be very useful to correctly understand the behaviour of a shallow geothermal reservoir subjected to heat extraction and/or injection by a ground source heat pump system. The present work illustrates the practical aspects and main issues occurred in the installation, testing and working phases of a monitoring system realised to record ground temperature in a geothermal application. The case study is a field of eight coaxial borehole heat exchangers, 30 m long, connected to a novel prototype of dual source (air and ground) heat pump.
Faculty of Mining, Geology and Petroleum Engineering
2018-11-08
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Geothermal special issue, December 2018
application/pdf
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7502
10.17794/rgn.2018.5.5
Rudarsko-geološko-naftni zbornik; Vol. 33 No. 5 (2018): No. 43 (special issue)
1849-0409
0353-4529
eng
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7502/4689
Copyright (c) 2018 authors and journal
https://creativecommons.org/licenses/by/4.0
oai:ojs.pkp.sfu.ca:article/7550
2018-11-30T16:59:31Z
rgn:SI43
Examining thermal conductivities of shallow subsurface materials for ground source heat pump utilization in the Pannonian part of Croatia
Borović, Staša
Urumović, Kosta
Terzić, Josip
Pavičić, Ivica
Thermogeological and hydrogeological properties of the shallow subsurface in the Croatian part of the Pannonian Basin System (PBS) were investigated in the context of its utilization for ground source heat pump (GSHP) systems installation. Detailed borehole core determinations, sampling and thermal conductivity measurements were conducted for seven boreholes at four locations in diverse geological settings. Results of 418 measurements conducted on 82 sediment and rock samples were compiled and analysed in the context of existing collections of thermal conductivities from Germany and Switzerland which are frequently utilized for borehole heat exchanger (BHE) dimensioning in other countries. Discrepancies have been detected between thermal conductivity data from different geographical regions and geological settings. These results imply that local data sets should be further developed to enable accurate BHE sizing. In four of the boreholes thermal response tests (TRTs) were also conducted so the results were compared to direct measurements on samples. The comparison demonstrated that in the environments with significant groundwater flow (coarser-grained sediments) the laboratory measurements systematically underestimated natural-scale thermal conductivities, while the discrepancies were low in finer-grained sedimentary environments. That is why in the presence of significant groundwater flow the TRTs are recommended for all installations, while at locations with low flow velocities the analogy to values cited in data collections can be used for small-scale installations. It is important to have the collection of measurements for local materials in cases when thermal response testing would not be economically feasible. The values reported in this paper can be a guideline for proper GSHP system dimensioning in order to achieve better performance, especially of small-scale systems in Croatia and other geologically comparable localities in the PBS area.
Faculty of Mining, Geology and Petroleum Engineering
2018-11-03
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Geothermal special issue, December 2018
application/pdf
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7550
10.17794/rgn.2018.5.3
Rudarsko-geološko-naftni zbornik; Vol. 33 No. 5 (2018): No. 43 (special issue)
1849-0409
0353-4529
eng
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7550/4687
Copyright (c) 2018 authors and journal
https://creativecommons.org/licenses/by/4.0
oai:ojs.pkp.sfu.ca:article/7575
2018-11-30T16:59:31Z
rgn:SI43
Identification of river Sava temperature influence on groundwater temperature of the Zagreb and Samobor-Zaprešić aquifer as a part of shallow geothermal potential
Kapuralić, Josipa
Posavec, Kristijan
Kurevija, Tomislav
Macenić, Marija
Based on the statistical analysis of the time series of data, the influence of the change of Sava River temperature and geothermal anomalies on the changes of the groundwater temperature of the Zagreb and Samobor-Zaprešić aquifers is described. In the analysis, data were used from daily measurements of the Sava River temperature and from the quarterly measurements of the groundwater temperature. Statistical methods of correlation, cross-correlation and linear regression were applied and the maximum, mean and minimum groundwater temperatures were analysed. Obtained results are presented in the form of statistical parameters, diagrams and maps of isotherms. This data is indispensable for development of shallow geothermal applications related to open loop groundwater heat pump systems. Since efficiency of the heat pump is directly dependent source temperature, presented analyses is necessary for prefeasibility study of geothermal projects and comparison between different designs. Furthermore, currently operating projects in the Zagreb and Samobor-Zaprešić are systematically elaborated, giving first approximation of energy consummation from this renewable energy resource.
Faculty of Mining, Geology and Petroleum Engineering
2018-11-20
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Geothermal special issue, December 2018
application/pdf
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7575
10.17794/rgn.2018.5.6
Rudarsko-geološko-naftni zbornik; Vol. 33 No. 5 (2018): No. 43 (special issue)
1849-0409
0353-4529
eng
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7575/4690
Copyright (c) 2018 authors and journal
https://creativecommons.org/licenses/by/4.0
oai:ojs.pkp.sfu.ca:article/7601
2018-11-30T16:59:31Z
rgn:SI43
Systematic review of research and utilization of shallow geothermal energy in Croatia
Macenić, Marija
Kurevija, Tomislav
Strpić, Kristina
Utilization of shallow geothermal energy is well known in several European countries. Even though large parts of Republic of Croatia show significant potential for it use, installation of ground source heat pump systems (heat pump and heat exchangers) is slowly progressing. Therefore, a short overview of so far published research concerning utilization and assessments of shallow geothermal potential for Croatia was done. In Croatia there is no agency or government department in charge of collecting and publishing data concerning installations of heat exchangers. Therefore, a study was done to collect available data of installed closed-loop heat exchangers either from scientific research or from personal contacts with drilling companies. Based on collected data a map was produced that shows general locations of installed heat exchangers. From obtained data of installed heat exchanger length, a first assessment of utilizing shallow geothermal potential in Croatia was given.
Faculty of Mining, Geology and Petroleum Engineering
2018-11-04
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Geothermal special issue, December 2018
application/pdf
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7601
10.17794/rgn.2018.5.4
Rudarsko-geološko-naftni zbornik; Vol. 33 No. 5 (2018): No. 43 (special issue)
1849-0409
0353-4529
eng
https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7601/4688
Copyright (c) 2018 authors and journal
https://creativecommons.org/licenses/by/4.0