What is a surge prediction valve?

Anti-surge valve is a device to prevent surge in the operation of centrifugal gas compressor.

Centrifugal compressor will surge when the output pressure is constant and the flow rate decreases to a certain value. In order to prevent surge, it is necessary to prevent airflow from entering the surge zone. In the operation of compressor, when the resistance of pipeline system increases, the flow rate will decrease, which may be lower than the allowable value. The task of the anti-surge system is to automatically open the vent valve or the bypass valve flowing back to the inlet when the flow drops to a certain lower safety limit, so as to increase the flow through the air compressor and prevent it from entering the surge zone. Take the lower limit of flow safety as the specified value of the regulator. When the measured flow value is higher than the specified value, the exhaust valve is fully closed; When the measured value is lower than the specified value, the regulator outputs a signal to open the exhaust valve to increase the flow. The perfect anti-surge device should be controlled according to the two signals of compressor outlet pressure and flow.

In a gas engine, when the turbocharger works in a high pressurization state and the throttle valve is closed, a great back pressure will be generated between the turbocharger and the throttle valve, so that the compressor impeller of the turbocharger stops working or the turbocharger surges. When the engine suddenly decelerates, the low pressure behind the throttle valve is transmitted to the pressure feedback joint of the surge valve through the vent hose of the surge valve, and the surge valve is opened to stop the diaphragm in one direction, so as to balance the pressure before and after the supercharger compressor and avoid the supercharger surge.

Anti-surge valve is the protection device of turbocharged engine, which ultimately prevents the turbocharger components from accelerating wear and fatigue.