An iterative numerical method to determine g-functions of borehole fields with the boundary condition of uniform temperature and time-constant surface-averaged heat flux is proposed. The method employs boundary conditions of uniform time-dependent temperature that converge to time-constant surface-averaged heat flux. Two simulations are sufficient for technical purposes, while additional simulations yield very precise g-functions with the desired boundary condition. The method is applied to analyze the overestimation of the g-function yielded by the condition of uniform and constant heat flux and the effects of the buried depth and of the spacing between boreholes on the g-function, for a 3 × 2 borehole field.
Naldi, C., Zanchini, E. (2019). A new numerical method to determine isothermal g-functions of borehole heat exchanger fields. GEOTHERMICS, 77, 278-287 [10.1016/j.geothermics.2018.10.007].
A new numerical method to determine isothermal g-functions of borehole heat exchanger fields
Naldi, Claudia
;Zanchini, Enzo
2019
Abstract
An iterative numerical method to determine g-functions of borehole fields with the boundary condition of uniform temperature and time-constant surface-averaged heat flux is proposed. The method employs boundary conditions of uniform time-dependent temperature that converge to time-constant surface-averaged heat flux. Two simulations are sufficient for technical purposes, while additional simulations yield very precise g-functions with the desired boundary condition. The method is applied to analyze the overestimation of the g-function yielded by the condition of uniform and constant heat flux and the effects of the buried depth and of the spacing between boreholes on the g-function, for a 3 × 2 borehole field.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
