A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Considering buried depth for vertical borehole heat exchangers in a borehole field with groundwater flow—An extended solution
Abstract The prediction of ground temperature is often necessary for the design and simulation of a borehole heat exchanger (BHE) system in its service life (which usually spans decades). A moving finite line source solution (MFLSD) calculates the ground temperature while considering the buried depth and groundwater flow for a single borehole. However, a BHE system normally comprises a borehole field containing multiple vertical boreholes in commercial (non-residential) applications to satisfy the intended heat demand of the project. Coupled with a spatial superpostion scheme, the MFLSD solution was extended from one single borehole to a borehole field. The MFLSD solution for borehole fields was numerically verified with an equivalent three-dimensional (3D) finite-element (FE) model developed in COMSOL Multiphysics. Then a sensitivity analysis was carried out to evaluate the effect of the buried depth on the heat transfer in borehole fields with groundwater flow. Results indicate that the negligence of buried depth leads to an over-prediction about the exploitable heat. This over-prediction is exacerbated by an increase in the number of boreholes in borehole fields, or by a decrease in the Peclet number. Considering the combined effect of buried depth and groundwater flow in a multiple borehole scenario, the extended MFLSD solution can help in a BHE system design for commercial applications.
Considering buried depth for vertical borehole heat exchangers in a borehole field with groundwater flow—An extended solution
Abstract The prediction of ground temperature is often necessary for the design and simulation of a borehole heat exchanger (BHE) system in its service life (which usually spans decades). A moving finite line source solution (MFLSD) calculates the ground temperature while considering the buried depth and groundwater flow for a single borehole. However, a BHE system normally comprises a borehole field containing multiple vertical boreholes in commercial (non-residential) applications to satisfy the intended heat demand of the project. Coupled with a spatial superpostion scheme, the MFLSD solution was extended from one single borehole to a borehole field. The MFLSD solution for borehole fields was numerically verified with an equivalent three-dimensional (3D) finite-element (FE) model developed in COMSOL Multiphysics. Then a sensitivity analysis was carried out to evaluate the effect of the buried depth on the heat transfer in borehole fields with groundwater flow. Results indicate that the negligence of buried depth leads to an over-prediction about the exploitable heat. This over-prediction is exacerbated by an increase in the number of boreholes in borehole fields, or by a decrease in the Peclet number. Considering the combined effect of buried depth and groundwater flow in a multiple borehole scenario, the extended MFLSD solution can help in a BHE system design for commercial applications.
Considering buried depth for vertical borehole heat exchangers in a borehole field with groundwater flow—An extended solution
Guo, Yunting (author) / Hu, Xincheng (author) / Banks, Jonathan (author) / Liu, Wei Victor (author)
Energy and Buildings ; 235
2021-01-03
Article (Journal)
Electronic Resource
English
Thermal response testing of compromised borehole heat exchangers
| Oxford University Press | 2013