Initial test campaign of an innovative dual source heat pump

Abstract

This paper describes the experimental setup and the test campaign performed on an innovative prototype of reversible dual source heat pump, with aerothermal and geothermal heat sources working with R32 as refrigerant. The addition of the air source allows the use each time of the most convenient source, hence leading to a considerably higher efficiency, as well as to dramatically reducing the size of the ground source heat exchanger so that the initial cost is much lower than the one of a full geothermal heat pump installation. The design and construction of this unit is the result of the research carried out under the frame of the GEOTeCH, project funded by the European Commission under the H2020 program. This paper first describes the employed experimental setup, and then presents the definition of the test matrix for the characterization of the heat pump performance under each operation mode, which has been based on the Design of Experiments methodology in order to minimize as much as possible the number of test points. 227 test points were acquired, what has allowed the characterization of the unit performance in all operation modes and a broad range of operating conditions, through adequate Response Surfaces. Finally, a comparison of the experimental performance results with the calculations performed with IMST-ART software is presented.