Possible ground energy uses in zones with anomalous gradient of temperature

In this paper, vertical ground heat exchangers in geothermal anomaly zones are investigated. In these contexts the ground can be used only as a source for heating and not for injecting heating during summer due to the high temperatures which might be reached. The aim of this study is the evaluation of the possibility to use the direct coupling between the building heating system and the borehole heat exchangers. In the North of Italy there are some places where thermal anomaly condition of the ground is present; the ground temperature can reach 70-85°C, therefore the mean temperature on a depth of 100 m below the ground can be around 30-35°C instead of usual values which are about 13-15°C. In the present study the energy analysis of a residential building has been carried out by means of the simulation tool TRNSYS, coupled with the CaRM model, developed by authors, which is able to consider in detail the thermal behaviour of the ground heat exchangers. Several thermal plant solutions have been analyzed.