Paper No 535 – Development and application of a new calculation method for double spiral ground heat exchangers – 14th IEA Heat Pump Conference, Chicago, USA
This study provides a new calculation method for double spiral ground heat exchangers (GHEs) and involves the combination of the analytical infinite line source (ILS), and infinite cylindrical source (ICS) models with the capacity resistance model (CaRM). Method adopts the concept of fin efficiency, enabling it to calculate underground temperature change easily and accurately, followed by integration into a simulation tool for ground source heat pump (GSHP) systems. Verification was done by comparing the simulation results with actual operating data, measured from a zero-energy building (ZEB) in Sapporo, Japan. Under conditions of instantaneous large heat injection, significant differences were observed between the simulation the actual measurements during initial 50 h. the number of temperature nodes in the network was increased to effectively reduce the error between simulations and measurements.