Ground heat exchanger thermal imbalance prevention using dynamic long-term ground temperature predictions

ABSTRACT

The authors present the development of a novel software and hardware package that dynamically predicts future ground heat exchanger temperatures to avoid thermal imbalance and future ground source heat pump system failure. In this study, an energy meter was installed on the ground heat exchanger of an office building and software was created on a remote server that collected the measured data. The future ground temperature was dynamically calculated, and the prototype was integrated with the building automation system to prevent future ground source heat pump system failure. The results showed that the building was cooling dominate and if the current mechanical system operation continued, the system would become inefficient in 16 years from high inlet temperatures to the heat pumps. A control sequence was developed for mitigating ground heat exchanger failure on the studied building. It was also determined by adjusting the set-point temperature of the make-up air unit from 12.8°C to 4.8°C, the amount of heating performed by the ground source heat pump system would increase to 49,230 kWh which maintained the calculated 20-year ground heat exchanger temperature below 32°C. The prototype developed in this paper is critical for maintaining an efficient ground source heat pump system and adequate ground heat exchanger temperatures. The outcome of this study provides the solution of ensuring a successful adoption of sustainable green technology on a large scale and eliminates ground source heat pump system failure due to thermal imbalance.

KEYWORDS:

• Sustainable energy technology
• ground source heat pump
• energy meter
• ground heat exchanger
• energy management

Acknowledgments

The authors thank Mark Mostowy and Bill Maughan from Steinbach Credit Union for providing access to their office building for the prototype installation. The authors would also like to thank Ian Lohrenz for assisting with the energy model development and Stephen Hak for assisting with the hardware installation.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.