A study of the thermal response of a borehole field in winter and summer
2013 (English)In: : ICAE2013-524, 2013Conference paper (Refereed)
A Ground Source Heat Pump system is a well-known technology used to provide space heating and cooling in residential and commercial buildings. For large energy demands, a number of boreholes, which can vary between tens and hundreds, may be required. The boreholes can be arranged in linear, square, rectangular, or any other configuration not necessarily symmetric. The heat exchangers in the boreholes are typically connected in parallel. Recently, the idea of a more flexible configuration of multiple Borehole Heat Exchangers (BHEs) has been introduced in commercial applications, enabling the system to operate in a more versatile manner, dividing the ground into different thermal zones. In this new arrangement, the BHEs are connected into thermal sub-groups allowing them to operate separately as sub-systems, depending on the building energy needs and the seasonal periods.
In this project, the temperature response of a multiple BHE configuration is obtained from simulations in a numerical model using FEM software, Comsol Multiphysics© under different operational conditions. First, the loads are imposed under the usual conditions so that all boreholes are operated to provide heating in winter and cooling in summer. The results of this study show that our numerical model presents a good agreement with the ones generated from EED when the system is balanced. Moreover, some hypothetical scenarios with respect to the BHEs arrangement and the operational mode are performed thanks to the flexibility of our numerical model. The hypothetical scenarios provide a first approach about the thermal behavior of the boreholes and their interactions within the field with respect to its wall temperature, previous operation and thermal storage. Further work will be devoted to study more realistic scenarios.
Place, publisher, year, edition, pages
ground source heat pump, borehole heat exchanger, g-function, numerical model, long term performance
IdentifiersURN: urn:nbn:se:kth:diva-131439OAI: oai:DiVA.org:kth-131439DiVA: diva2:656234
International Conference on Applied Energy ICAE Jul 1-4, 2013, Pretoria, South Africa
QC 201310222013-10-152013-10-152016-09-23Bibliographically approved