Simulation of a domestic ground source heat pump system using a transient numerical borehole heat exchanger model

Common approaches to the simulation of Borehole Heat Exchangers (BHEs) assume heat transfer in circulating fluid and grout to be in a quasi-steady state and ignore fluctuations in fluid temperature due to transport of the fluid around the loop. However, in domestic ground source heat pump systems, the heat pump and circulating pumps switch on and off during a given hour; therefore the effect of the thermal mass of the circulating fluid and the dynamics of fluid transport through the loop has important implications for system design. This may also be important in commercial systems that are used intermittently. This paper presents transient simulation of a domestic Ground Source Heat Pump (GSHP) system with a single BHE using a dynamic three-dimensional numerical borehole heat exchanger model.