The cost of manufacturing, installing and maintaining heat pumps needs to come down to make environmentally-friendly heating systems more competitive. Furthermore, the F-Gas regulation of the European Union specifies that climate harmful refrigerants must be drastically reduced in appliances. This is the dual impetus behind a new project from the Fraunhofer Institute for Solar Energy Systems (ISE) that will develop refrigeration circuits for heat pumps to operate as efficiently as possible using the minimum amount of refrigerant.
The team will construct between 40 and 80 brine heat pump prototypes that use the climate-friendly refrigerant propane to transport heat from the cold to the warm side of the process. Working closely with industrial part suppliers, the team will test dozens of individual components assembled in a variety of configurations to determine the best arrangement for propane reduction.
The measurement tests will run in parallel for a year and will capture data at multiple operating points. The Technical University of Valencia is developing a predictive simulation tool to support the new designs. An automated system for charging and discharging the refrigerant will also be developed to eliminate the need for manual handling of volatile propane by trained specialists.
“This setup enables us and the project partners to acquire an extensive, multidimensional dataset in a comparatively short time, thus laying the foundation for the rapid market implementation of refrigeration circuits with significantly-reduced refrigerant charge," explains Dr Lena Schnabel, head of the Department of Heating and Refrigeration Technology at Fraunhofer ISE in a .
The project “LC150 – Development of a Refrigerant-reduced Heat Pump Module with Propane” is funded by the German Federal Ministry for Economic Affairs and Energy (BMWi).