Geothermal helical heat exchangers: Coupling with a reversible heat pump in western Europe

摘要

This paper presents a computational analysis of geothermal heat pump used to assess the thermal needs of a 120 m(2) low-energy house. Helical heat exchangers are used to extract or inject heat into shallow subsoil. Two 2D-axisymmetric models of helical heat exchangers are compared. The frozen of the subsoil such as its thermal relaxation during the summer are analysed. The performance of the exchangers is being studied over a 10-year period. The impact of the heat-pump operating modes (short cycles vs. long cycle) on the system efficiency is assessed, and the influences of the subsoil properties and of the geometry of the geothermal exchangers are further studied. A sizing law relating the number of exchangers to be used and their height/diameter is proposed. (C) 2015 Elsevier Ltd. All rights reserved.