Compressor – Thermodynamics and acoustics
Hermetic refrigerant compressors have various sources of losses, including thermodynamic, mechanical, and electrical losses, with thermodynamic losses characterizing the major part of the losses . Approaches to increase efficiency often failed due to excessive pressure pulsations. Proven damping methods like Helmholtz resonators effectively minimize these pulsations at constant speeds, while innovative approaches aim to reduce pressure pulse sources through flow-acoustic optimization at variable speeds. In summary, there is a trade-off between thermodynamic efficiency and the transmission of pulsations and acoustic issues.
Acoustic emissions are addressed with innovative pressure pulse shielding and passive absorbers along the transfer path. These measures collectively improve efficiency and reduce noise without compromising system functionality.
Studies have shown that pulsation damping measures, such as symmetrical and asymmetrical nozzles, can reduce pressure fluctuations in gas flows. Therefore further investigations on a novel assisted valve system will be explored to improve compressor efficiency and acoustics. Initial tests with commercially available subsystems are promising, and further adaptations by research partners are planned.
