P15 Hybrid system for free cooling from compressor refrigeration systems
 frikyla_princip Project leader Björn Palm
Performer KTH

The project has been terminated due defection of co-financier

Refrigeration systems often use ambient air as heat sink. In temperate climates, part of the year it is possible to get sufficient cooling by free-cooling. This usually requires a separate free-cooling system. It is, however, possible to use the existing cooling system and allow it to act as a two-phase thermosyphon when the temperature conditions allow. Dantherm, our industrial partner, wants to develop this type of system for cooling radiobase stations. As the electronics in these cases accepts higher temperatures than 22C, free cooling will be useful more days per year than for comfort cooling. A good solution can, however, be used for several other applications. The solution requires bypass of the compressor and the expansion valve during free-cooling. The difficulty is to get good performance both in normal operation and in free-cooling. The project includes simulation of the system and practical tests to verify the simulation and to identify solutions which give good performance.