Thermo-Mechanical Behavior Analysis of Heat Exchanger Piles by Numerical Modelling

Using renewable energy sources instead of fossil fuels is a fundamental way to reduce environmental pollution caused by greenhouse gases. Geothermal energy is available all over the world and has an important role in the supply of renewable energy. In order to collect geothermal energy various heat exchanger systems have been developed in recent years that thermal activated piles (energy piles) are one most of them. Reinforced concrete piles have been widely used as a geothermal heat exchanger to access the relatively constant temperature of the ground for efficient heating and cooling of buildings. Energy piles are heat capacity systems that have been increasingly exploited to provide both supplies of energy and structural support to civil structures (Batini et al., 2015). Concrete has a good thermal conductivity and thermal storage capacity, which makes it an ideal medium as an energy absorber (heat exchanger). To use these properties for energy foundations, high-density polyethylene plastic pipes have to be installed within the concrete. The plastic piping can be fixed to the reinforcement cages of the energy foundation in a plant or on the site (Fig. 1).