Danfoss has published a whitepaper highlighting the vibration reduction capabilities of BOCK HGX CO₂ compressors in a transcritical booster refrigeration system at a supermarket in Ohio, USA. The test, part of a retrofit installation, showed that the compressors reduced vibration significantly, supporting smoother and quieter operation. This reduction addresses one of the common challenges of CO₂ systems in food retail.
The system under evaluation included low-temperature (LT) and medium-temperature (MT) suction groups on a single rack, equipped with BOCK HGX compressors, a variable frequency drive (VFD), a gas cooler, high pressure valve, and flash gas bypass valve. Danfoss engineers conducted vibration measurements using a calibrated meter at multiple points on the rack, compressors, and common piping.
The test showed vibration reductions between 48.3% and 97.7% compared to previous compressors, with an average reduction of 83% across all capacity combinations and direction vectors. The lead compressor with the VFD enabled a wider operating frequency range of 35–70 Hz, compared to 40–60 Hz previously, expanding the system’s capacity range without increasing vibration.
Reduced vibration led to less noise, minimized shaking of piping and rack components, and improved working conditions for maintenance staff.
“We are encouraged by the test results that affirmed the operational and sustainability benefits of BOCK compressors for transcritical CO2 refrigeration systems,” said Chris Brown, application engineering manager at Danfoss.
