Computational Modeling and Sensitivity Analysis of Horizontal Slinky Heat Exchangers for GSHPs

Ground source heat pump (GSHP) systems have a good environmental compatibility and also low impact on rooms reserved to heating and cooling systems in buildings. The choice of the GSHP has, anyway, to be justified by cost advantages in many applications, such as commercial and industrial buildings,. Vertical heat exchangers are very efficient, but expensive as drilling costs are highly dependent on ground composition. Horizontal slinky ground heat exchangers are an alternative solution and can represent a good compromise between efficiency and costs. This work verifies numerically, with the help of the CFD code Fluent, the operating conditions for horizontal slinky heat exchangers, placed under the ground level in the South of Italy, for a building which had to be provided with an air conditioning system for both winter and summer. In particular, the dependence of the efficiency of the system on the parameters like the spires step, the depth of installation and the water inlet velocity have been investigated.