Optimisation of energypilots for using geothermal energy

Fortifying the potential of using the earth's heat and cold with piles for sustainable construction.

Moving our society towards Nearly Zero Energy Buildings (NZEB) requires the application of renewable sources of heat and cold that are cost-effective enough to be put into practice. A system for using the heat and cold of the earth to heat and cool buildings through thermally activated foundation piles - the so-called energopilot - has this potential. By equipping the foundation piles with a liquid circuit pipe, it allows, at low cost, to exploit the favourable and relatively stable ground temperature over time and, in combination with a heat pump, to achieve high heating and cooling factors compared to other energy sources. The energy yield and cost-effectiveness for a given foundation condition has to be designed and assessed individually in relation to the type of building and the way it is operated. For this purpose, a numerical model of heat transfer in the energy storage and surrounding soil must be developed, linked to a model of the building and its energy systems and appropriate optimisation methods applied. The implementation of enegopiles in the Czech Republic is limited, among other things, by the concerns of structural engineers, because the thermal activation of enegopiles affects the structural-mechanical function of foundation piles, in particular by their thermal expansion, which negatively affects the cladding friction and can thus reduce their load-bearing capacity and serviceability. In order to assess this influence, computer simulations and experimental measurements of the mechanically and thermally loaded piles should be carried out, and the results obtained should be processed into design software that will be an aid to building structural experts.

In December 2020, the project duration was extended until the end of 2022 The project results will be extended with new features during the extension.

Keywords

foundation piles; ground heat exchanger; optimization; computer modeling; energy efficiency of buildings; renewable energy

Project results

Energopilot thermal modelling software: this software will allow the evaluation and optimisation of the heat flux of energopilots with liquid circuit.

Software for structural-mechanical design of thermally loaded piles using the EpMPF 1.0 transfer function method: this software will enable the thermal-mechanical design of energy pilots. It will be applicable for the design of bearing capacity and settlement of piles with additional cyclic thermal loading.

Project partners