Long-Term Detailed Monitoring and Energy Performance Evaluation of a Ground Source Heat Pump System. A Study Case in Catalonia

Abstract

An exhaustive data analysis was undertaken in a remotely monitored shallow geothermal energy (SGE) installation. The system operates since 2012 as the heating and cooling facility of an office building located in Tremp (Lleida, Spain). The performance parameters recorded by its monitoring system account basically for the flow rates and flow temperatures, heating, domestic hot water production and cooling, electrical energy consumption and compressor operation time of the ground source heat pump (GSHP). Through the proper selection of the sampling frequency (minute-resolved) and a smart data processing, it was demonstrated the potential of continuous monitoring plus data analysis as an effective and efficient tool for diagnostics and fault-detection in GSHPs operating under real conditions. In particular, a faulty 3 way valve was identified thanks to the analysis of the data, and a progressive degradation in performance was identified and quantified. This fact motivated extra physical inspection that brought up new maintenance needs. The results of the analysis were supported by simulations carried out under Ground Loop Design software environment, and several sensitivity analyses were carried out to evaluate the influence of key parameters of the installation on its seasonal performance. As a result, this work opened new opportunities for the optimization of GSHP seasonal performance.