Seasonal energy extraction and storage by deep coaxial borehole heat exchangers in a layered ground

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F24%3A10489458" target="_blank" >RIV/00216208:11320/24:10489458 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=j~BkmUM8pZ" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=j~BkmUM8pZ</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.renene.2024.121530" target="_blank" >10.1016/j.renene.2024.121530</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Seasonal energy extraction and storage by deep coaxial borehole heat exchangers in a layered ground

Popis výsledku v původním jazyce

Geothermal energy extraction and storage through boreholes have garnered significant attention, particularly regarding deep coaxial borehole heat exchangers. They can be modeled as linear systems if the water flow rate remains constant. The amplitude and phase shift of the transfer functions between the energy output of the exchanger and the thermal changes in the flowing water can be established analytically, provided that the operating regime is periodic over time. We begin by presenting a theoretical framework fora borehole situated in a homogeneous layer and subsequently extend the theory to a layered ground model using a matrix method. The applicability of our approach is demonstrated over operational periods of up to one year for typical exchangers with a radius of 0.2 m, reaching depths from several hundred meters to 1 km. Temperature variations of several degrees Kelvin in the inflowing water are associated with storage and extraction power amplitudes of several kilowatts fora 1 km deep borehole. We illustrate how the ratio between power and temperature amplitudes varies with changes in borehole radius and depth. Furthermore, we show that for very deep boreholes extending to a depth of 4 km, the borehole heat exchangers reach their maximum storage capacity.

Název v anglickém jazyce

Seasonal energy extraction and storage by deep coaxial borehole heat exchangers in a layered ground

Popis výsledku anglicky

Geothermal energy extraction and storage through boreholes have garnered significant attention, particularly regarding deep coaxial borehole heat exchangers. They can be modeled as linear systems if the water flow rate remains constant. The amplitude and phase shift of the transfer functions between the energy output of the exchanger and the thermal changes in the flowing water can be established analytically, provided that the operating regime is periodic over time. We begin by presenting a theoretical framework fora borehole situated in a homogeneous layer and subsequently extend the theory to a layered ground model using a matrix method. The applicability of our approach is demonstrated over operational periods of up to one year for typical exchangers with a radius of 0.2 m, reaching depths from several hundred meters to 1 km. Temperature variations of several degrees Kelvin in the inflowing water are associated with storage and extraction power amplitudes of several kilowatts fora 1 km deep borehole. We illustrate how the ratio between power and temperature amplitudes varies with changes in borehole radius and depth. Furthermore, we show that for very deep boreholes extending to a depth of 4 km, the borehole heat exchangers reach their maximum storage capacity.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10500 - Earth and related environmental sciences

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Renewable Energy

ISSN

0960-1481

e-ISSN

1879-0682

Svazek periodika

237

Číslo periodika v rámci svazku

October

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

16

Strana od-do

121530

Kód UT WoS článku

001341069900001

EID výsledku v databázi Scopus

2-s2.0-85206628918