ISE Team develop refrigeration circuits for heat pumps

The Fraunhofer Institute for Solar Energy Systems ISE is developing refrigeration circuits for heat pumps which shall operate as efficiently as possible with low amounts of the climate-friendly refrigerant propane. This research is carried out in project “LC150 – Development of a Refrigerant-reduced Heat Pump Module with Propane”.

The Fraunhofer ISE team is developing a system for automatic refrigerant charging and discharging to avoid the time-consuming task of manually handling the propane by trained specialists.

During the tests, sensors record temperature, pressure, power consumption and volume flows in the prototypes, and the data is automatically loaded into the evaluation software. With this data, the seasonal efficiency of each heat pump assembly with its respective refrigeration circuit can be estimated. Furthermore, the quantity and type of oil in the compressor are being varied.

Based on the measurement results, the Fraunhofer ISE researchers will select the component combinations, which show the most promise for further reducing the amount of propane, to undergo long-term tests.

From the acquired database, the researchers aim to derive methodical correlations which can be used to design refrigerant-reduced heat pumps with less effort in the future.