P16 Comparative experimental investigation of performance and efficiency of ground collectors for vertical borehole applications

Project leader Saqib Javed
Performer Chalmers Tekniska Högskola AB

The number of heating and cooling systems using vertical boreholes is increasing rapidly in Sweden. Currently, there are over 400,000 installations, mostly using U-tube collectors. Many new collector types have been launched in recent years. This project will perform comparative investigations of these collectors. The aim is to test thermal and hydraulic performance of the collectors under similar conditions. Based on outcomes of the comparative analysis, best performing collector types, for different scenarios of operating modes, heat injection/extraction rates, temperature difference over the collector and flow rates, will be identified. Projected outcomes include significant reduction in pumping powers and improvements in energy performance of borehole systems. Substantial reductions in required borehole depths are also expected. The project is an important step towards development of an international centre for testing and certification of ground collectors from all over the world.