|Publikationstitel:||Langzeiterfahrungen mit Erdwärmesonden-Systemen in der Schweiz - Schlussbericht|
|Projekt:||103022 - Langzeiterfahrungen mit Erdwärmesonden-Systemen in der Schweiz
Alle Publikationen zu diesem Projekt anzeigen ARAMIS-Projektbeschreibung
|Datum der Veröffentlichung:||19.03.2010|
|Auftragnehmer/in:||Geowatt AG | Dohlenweg 28 | 8050 Zürich|
|Autoren/innen:||Sarah Signorelli | Geowatt AG | firstname.lastname@example.org
Sabin Imhasly | Geowatt AG | email@example.com
Ernst Rohner | Geowatt AG | firstname.lastname@example.org
Ladislaus Rybach | Geowatt AG | email@example.com
|Verfügbare Dokumente:||000000290319 ( de, 1174 kb )|
|Abstract:||Borehole heat exchanger (BHE) systems are widely-used in Switzerland and they provide an economically and ecologically reasonable alternative to other heating systems. In this project, experiences with BHE systems that have been operating for decades in Switzerland were registered and evaluated. The analysis allows the assessment of the long-term production’s sustainability.
As a first project step, „old“ facilities were investigated and a survey was conducted among the owners. The focus was on finding out how well the borehole heat exchangers operate on the long run and how satisfied the owners are with their system. The analysis of the survey showed that practically all facilities are still operating. About 90 % of the owners are satisfied or very satisfied and would choose such a system again.
Most facilities still operate faultlessly. The few problems that arose could mostly be linked to the heat pump or the borehole heat exchanger. Half of the problems concerning the borehole heat exchanger are due to underdimensioned BHE length. It is recommended to pay attention to the professional design of the borehole heat exchanger.
The survey also shows that borehole heat exchangers can be overloaded, if an old heat pump is replaced by a new one with a higher COP. Therefore for any replacement, it should be clarified that the existing borehole heat exchanger is adequate to the evaporator capacity. The heat pump and the borehole heat exchanger have to be adjusted to each other. Important information about the professional dimensioning and operation of BHE are included in the SIA 384/6 norm.
The general satisfaction of owners of ground-source heat pump systems has also been shown by two studies recently published in Germany; Most constructors would choose a ground heat solution again. Yet the timescale of these studies is essentially smaller than the timescale for the data presented herein.
In a second project step, data of two facilities has been analyzed and resimulated numerically. Forward modelling of both facilities for an operation period of 50 years shows that the operation of BHE systems is sustainable. Furthermore, by analyzing the operating data it could be shown that the heat generation costs are clearly competitive.
In general, the facilities proved to be reliable in the long run, too, which guarantees sustainability of productivity. This result is also remarkable by international comparison, since this evidence has been provided for the first time on the basis of data from operating facilities.