摘要:
A dual centrifugal compressor refrigeration system has one evaporator for both compressors. The evaporator provides the centrifugal compressors with refrigerant vapor through separate suction connections for each compressor. Each suction connection has a protrusion that extends into the evaporator vessel to disturb the axial flow of refrigerant vapor in the evaporator vessel. The disturbance of the axial flow of refrigerant vapor in the evaporator vessel permits a surging compressor to draw refrigerant vapor in order to recover from the surge condition.
摘要:
A control system is provided to maintain stable operating conditions for centrifugal compressors operating in parallel when one of the centrifugal compressors enters into an unstable operating condition. The control system determines an unstable operating condition in response to signals indicating the motor current or power consumption of each compressor and the position of the pre-rotation vanes of the compressors. Once an unstable operating condition is determined, the control system closes the pre-rotation vanes to each compressor until the unstable operating condition has been corrected.