Ground Moisture Condensation around the GSHP Borehole

Abstract

Presented in this article are the results of theoretical research carried out with financial support from the Ministry of Education and Science of the Russian Federation (contract ID RFMEFI57914X0026) and demonstrating the need to consider the changes in ground heat transfer properties in geothermal borehole heat modeling, due to moisture condensation/evaporation in the ground pores. It is our opinion that in GSHP systems design, the quantity of the boreholes is often overestimated and the associated parameters oversized while the extent of the ground heat transfer is underestimated. In most cases, in designing GSHP operation and performance, this is due to the incorrect assessment of the ground moisture content, which has a most tangible effect on the ground heat transfer properties. This article demonstrates the need to consider the ground moisture condensation/evaporation in GSHP systems design. Presented in the article is the mathematical simulation of the ground pore moisture condensation at the GSHP boreholes. Also presented is numerical data derived from the calculations to assess the effect of the ground pore moisture condensation on the borehole heat transfer efficiency. Through analysis and experimentation, it was determined that the ground pore moisture condensation have a substantial impact on the GSHP efficiency.

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