Compressor stall

With surge protection is called a measure that protects the turbo compressor from continued pumping when the surge control has failed. This second safety measure is important since the operation of the pump must be prevented in order to avoid destruction of the compressor.

Pump and compressor map

The compressor map is divided by the surge line in a stable and an unstable region. Pump occurs when the operating points of the compressor, advised by reducing the flow rate ( throughput) or by increase of discharge pressure ( head ) in the unstable region, the left in the map. Pump is characterized by cyclic pumping and return flow of the compressed medium, accompanied by high vibrations, pressure shocks and rapid temperature rise in the compressor. Possible consequences include warehousing, Rubbing, impeller or blade damage that can lead to operational failures. To avoid this, centrifugal compressors are equipped with appropriate safeguards.

Surge protection

Turbo compressors should be equipped with two independent systems for pump monitoring: The actual protection against the pump itself represents the surge control that keeps the capacity of the compressor on the minimum allowable value when approaching the surge line by opening a relief valve. Only in case of failure of this control or at very fast malfunctions occur, the anti-surge control is to intervene. This detects the first surge and prevents, for example by rapid opening of relief valves, or Abblaseklappe (s) further pumping. In addition, as soon as possible the power is reduced and, if available, as are the adjustable inlet guide vane are closed. For relief valves, the slotted disc valve has been found with an integrated pneumatic actuator as particularly advantageous anti-surge valve.

• Turbomachinery