A model for annual simulation of standing column well ground heat exchangers

Standing column wells can be used as highly efficient ground heat exchangers in geothermal heat pump systems. This paper describes a computationally efficient numerical model of groundwater flow and heat transfer in and around standing column wells. An approach that utilizes an "enhanced" thermal conductivity to account for the natural groundwater movement, but which explicitly models the induced groundwater flow by "bleed," is proposed. This model has been validated with experimental data and a reference numerical model (Spitler et al. 2002; Rees et al. 2004; Deng 2004). This simplified model is intended for use in hourly simulation programs or design tools.