Surge protection
With surge protection refers to a measure that the turbo compressor from prolonged pump protect when the surge control has failed. This second safety measure is important because the pump mode of operation must be avoided in order to avoid the destruction of the compressor.
Pumps and compressor map
The compressor map is divided into a stable and an unstable area by the surge limit. Pumping occurs when the operating points of the compressor get into the unstable area on the left in the map due to a reduction in the delivery rate (throughput) or an increase in the final pressure (delivery head). Pumping is characterized by cyclical pumping and backflow of the compressed medium, accompanied by high vibrations, pressure surges and rapid temperature increases in the compressor . Possible consequences are bearing, rubbing, impeller or blade damage , which can lead to operational failures . To avoid this, turbo compressors are equipped with appropriate protective mechanisms.
Surge protection
Turbo compressors should be equipped with two independent systems for pump monitoring: The actual protection against pumping is provided by the anti-surge control , which, when the surge limit is approached, keeps the flow rate of the compressor at the minimum permissible value by opening a relief valve . The pump protection control should only intervene if this regulation fails or if faults occur very quickly. This detects the first pumping surge and prevents further pumping, for example by quickly opening the relief valve or blow-off flap (s). In addition, the output can be reduced as quickly as possible and, if available, the adjustable guide vane can also be closed. The slotted disc valve with an integrated pneumatic actuator has proven to be a particularly advantageous anti-surge valve for relief valves.