Optimization methodology for GSHP installations based on the circulation pumps frequency variation

Abstract

Geocool plant was the result of a EU project whose main purpose was to adapt ground source heat pump technology to cooling dominated areas. The installation was finally built by the end of year 2004 and it has been monitored since February 2005 until nowadays. In April 2011, in the framework of another European project, Ground-med, the old heat pump (ON/OFF compressor) located at the Geocool plant was replaced by a new more efficient design with two compressors (ON/OFF) of the same capacity working in tandem. In order to optimize the energy performance of the installation, a new methodology based on the frequency variation of the circulation pumps was developed for both systems: Geocool (1 compressor ON/OFF) and Ground-med (2 compressor ON/OFF in tandem), so that it is possible to experimentally determine the optimal frequencies for the circulation pumps as a function of the thermal energy demand of the building along the day for both systems. This work presents the optimisation methodology for both systems.