Parametric study for the long term energetic performance of geothermal energy piles

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Researchers

Research units

  • Tallinn University of Technology

Abstract

Geothermal energy constitutes an important renewable resource that will become increasingly prominent in future constructions. A common method of extraction and usage consists of installing, inside the foundation piles of buildings, U-shaped heat exchangers called "energy piles". In this paper such installations are addressed by means of a full parametric study, performed for a hall-type commercial building in a cold climate. By computing the transient heat transfer between energy piles and ground for a period of 20 years, guidelines for a preliminary sizing of the geothermal system as a whole are provided. These are valid for this specific building and climate, for a clay-type soil and without assuming thermal storage. A highly nonlinear behaviour of the expected yield in relation to pile separation and evaporator extraction power is observed. Furthermore, 15m-long piles are found to be more efficient than those with double length, a smaller extraction power seems to be more favourable and differences in the pile diameter have little impact for heat transfer. A geothermal system sizing guide, which is useful for a preliminary quantitative test prior to any installation, is introduced. Even though our specific results are valid only for a commercial hall-type building in Finland, our procedure is qualitatively general and can be utilized for any given building type and climate zone.

Details

Original languageEnglish
Title of host publication1st Nordic conference on Zero Emission and Plus Energy Buildings, 6-7 November 2019, Trondheim, Norway
Publication statusPublished - 1 Jan 2019
MoE publication typeA4 Article in a conference publication
EventNordic Conference on Zero Emission and Plus Energy Buildings - Trondheim, Norway
Duration: 6 Nov 20197 Nov 2019
Conference number: 1

Publication series

NameIOP Conference Series: Earth and Environmental Science
PublisherInstitute of Physics Publishing
Number1
Volume352
ISSN (Print)1755-1307

Conference

ConferenceNordic Conference on Zero Emission and Plus Energy Buildings
Abbreviated titleZEB+
CountryNorway
CityTrondheim
Period06/11/201907/11/2019

ID: 38943550