Compressor stability & thermal decoupling — motor yacht 100m+

The hydraulic separator was unable to perform its intended buffering function because primary flow volume consistently exceeded secondary circuit demand. Cold supply water recirculated back to the chiller inlet without absorbing heat from the distribution side, creating a false signal that triggered continuous compressor operation. The root cause was a combination of fixed-speed primary pumping and inlet-based control logic. After adjusting the control strategy to respond to actual return temperatures and demand, the thermal buffer began functioning correctly and compressor cycling was eliminated.

The chiller control system was configured to respond to supply water inlet temperature rather than return temperature. This caused the system to interpret normal temperature fluctuations as demand signals, triggering rapid start/stop sequences. By shifting the control reference and introducing a wider operating bandwidth, the system response became proportional to actual load rather than short-term temperature noise. System COP stabilised at 7.18 following the adjustments.