Effect of borehole short-time-step performance on long-term dynamic simulation of ground-source heat pump system

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • C. K. Lee

Detail(s)

Original languageEnglish
Pages (from-to)238-246
Journal / PublicationEnergy and Buildings
Volume129
Publication statusPublished - 1 Oct 2016

Abstract

Despite many studies that were found in the literature regarding the modelling of the short-time-step (STS) behaviour of the borehole ground heat exchangers, reported investigations of its effect on the long-term dynamic simulation of a ground-source heat pump (GSHP) system were sparse. Hence, in this study, the dynamic performances of a GSHP system applied to an office zone in Hong Kong over a period of 10 years were compared with both the long-time-step (LTS) and STS approaches for the boreholes. It was found that with the adoption of the more appropriate STS approach, the simulated fluid temperature leaving the ground heat exchanger borefield was lower by at most 1.62 °C over a range of ground and grout thermal conductivities investigated. This also allowed the design borehole length to be reduced by at most 14.4% while the resulting energy consumption was still better than those based on the LTS approach. In this regard, the STS approach should be employed in the long-term dynamic simulation of GSHP systems.

Research Area(s)

  • Borehole, Dynamic system simulation, Ground heat exchanger, Ground-source heat pump, Short-time-step