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Surge Limit is the Minimum Flow Point ( in the compressor characteristic curve ) below which the compressor operation become instable. If the flow-rate is reduced, the pressure developed by the compressor decreases. Then, the pressure in the discharge line becomes greater , and the gas flow back into the compressor. As soon as the pressure in the discharge line drops to below that developed by the compressor, the gas again flows in the discharge line. Then, the cycle repeats. The oscillating pressure and flow rate will cause audible vibrations and shocks, and could damage the compressor blades, seals, and other components. Therefore, the compressor requires an antisurge control system to limit the flow rate at a minimum point, safely away from the surge limit.
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What is Surge in centrifugal compressor?
Surge is a flow instability that results in a global collapse of flow through the compressor. Compressors do not continue to operate or flow once surge has occurred. Surge should be avoided. Surge is not the rough operation, vibration, pulsation, or noise that develops at low flow conditions. Surging is a momentary reversal of flow.When the pressure in the centrifugal comp. increases,the mass flow rate decreases.There is a limit up to which the pressure can be increased,then after the flow becomes instable and momentary reversal of flow take place,vibrations are produced and mechanical damage occurs.
What is surging in compressor?
Centrifugal and axial compressors will surge when forward flow through the compressor can no longer be maintained, due to an increase in pressure across the compressor, and a momentary flow reversal occurs. Once surge occurs, the reversal of flow reduces the discharge pressure or increases the suction pressure, thus allowing forward flow to resume again until the pressure rise again reaches the surge point. This surge cycle will continue until some change is made in the process or compressor conditions.
Why use surge protecting resistor to generator rotor winding?
To limit the fault current used surge protective resistance in generator rotor winding to protect the rotor winding heavy damage.
Makeup gas compressor spill back valve function?
It is a quick response valve, which opens fully in 1.5-2 seconds. basically will be of fail open type. Its opening depends on the surge control.
What is surge in gas turbine?
Surging in gasturbine means that the pressure at the delivery end of the gas turbine compressor becomes very high (as a result of reduced flow at the compressor outlet). When this happens, the compressor pressure at the delivery end increases as the flow decreases upto an extent after which the pressure does not increase and there is a flow reversal. This flow reversal releases the sudden pressure that developed on account of reduced flow. The flow reversal is accomplanied with a loud noise and tremendous vibration. Surging affects the whole machine and if it is of high magnitude, the gas turbine can be ripped apart. Anti-surge devices (Bleed valves) are installed which do not allow the flow to reduce even on low speeds and keep a certain air flow from the compressor during times of low air requirement (startup and shutdown) Surging in gasturbine means that the pressure at the delivery end of the gas turbine compressor becomes very high (as a result of reduced flow at the compressor outlet). When this happens, the compressor pressure at the delivery end increases as the flow decreases upto an extent after which the pressure does not increase and there is a flow reversal. This flow reversal releases the sudden pressure that developed on account of reduced flow. The flow reversal is accomplanied with a loud noise and tremendous vibration. Surging affects the whole machine and if it is of high magnitude, the gas turbine can be ripped apart. Anti-surge devices (Bleed valves) are installed which do not allow the flow to reduce even on low speeds and keep a certain air flow from the compressor during times of low air requirement (startup and shutdown)
What does means surge on centrifugal compressor?
Surge is a point when compressor is not add enough energy to overcome system resistance.
How do you calculate surge in compressor?
fool
How do you find centrifugal compressor is in surge?
Normaly, every centrifugal type comprssors provided with an antisurge valve or surge control valve. when compressor handelled with surge, the proveded surge control valve will become open automatically and the cycle will repeated till the comprssor is in surge.
What is Surge in centrifugal compressor?
Surge is a flow instability that results in a global collapse of flow through the compressor. Compressors do not continue to operate or flow once surge has occurred. Surge should be avoided. Surge is not the rough operation, vibration, pulsation, or noise that develops at low flow conditions. Surging is a momentary reversal of flow.When the pressure in the centrifugal comp. increases,the mass flow rate decreases.There is a limit up to which the pressure can be increased,then after the flow becomes instable and momentary reversal of flow take place,vibrations are produced and mechanical damage occurs.
Can reciprocating compressor surge?
Compressor surge only occur in centrifugal compressors. reciprocating compressor don't as they increase pressure by volume reduction, unlike centrifugal compressors where they increase pressure by converting kinetic energy to potential energy (pressure).
Why does a compressor surge happen?
Compressor surges can happen when there is a line spike, during storms or when other equipment is plugged in on the same electrical line. An industrial surge protector can help eliminate power surges.
What is the cause of stall and surge in compressor?
stall and surge is caused when the flow in the compressor loses enthalpy and static energy so that it does not have enough power to approach the end of the axis; thus it remains in the annolus of the compressor and creates a stall cell. these cells gradually join each other and create stall zones which are rotating about the axis and are some times called rotating stall. if this stage does not get stopped, the stall cells will cover the whole annolus and will stop the fluid flow through the stages of the compressor and finally lead to surge. if surge happens, the compressor will be out of order.
What is surging in compressor?
Centrifugal and axial compressors will surge when forward flow through the compressor can no longer be maintained, due to an increase in pressure across the compressor, and a momentary flow reversal occurs. Once surge occurs, the reversal of flow reduces the discharge pressure or increases the suction pressure, thus allowing forward flow to resume again until the pressure rise again reaches the surge point. This surge cycle will continue until some change is made in the process or compressor conditions.
What is compressor turndown?
Turndown: The allowable operating range for the centrifugal compressor between the design point and the surge line at any given speed for a fixed compressor head.
Why does your 95 s10 4.3z surge with air compressor on?
The ac compressor may be on its way out and binding. Disconnect it before it fills the ac system with trash.
What is surging in axial compressors?
Surge is defined as the operating point at which the compressor peak head capability and minimum flow limit are reached. The compressor loses the ability to maintain the peak head when surge occurs and the entire system becomes unstable. Under normal conditions, the compressor operates to the right of the surge line. However, as fluctuations in flow rate occur, or under startup / emergency shutdown, the operating point will move towards the surge line because flow is reduced. If conditions are such that the operating point approaches the surge line, the impeller and diffuser begin to operate in stall and flow recirculation occurs. The flow separation will eventually cause a decrease in the discharge pressure and flow from suction to discharge will resume. This is defined as the surge cycle of the compressor.The surge cycle will repeat itself unless control systems are installed or operational changes are made to bring the compressor out of the surge cycle. The surge cycle may result in a small or large flow reversal period depending on the discharge gas volume and the pressure ratio. Chronic surge is characterized by intermittent periods of small flow reversal that may not cause severe damage to the machine. Acute surge is more pronounced, usually due to a rapid transition across the surge line. Any surge event can cause severe damage to the thrust bearings, seals, and the impeller.
Why could a turbocharger be surging?
Compressor surge is when the air pressure after the compressor is actually higher than what the compressor itself can physically maintain. This condition causes the airflow in the compressor wheel to back up, build pressure, and sometimes stall. Common conditions that result in compressor surge on turbocharger gasoline engines are: * A compressor bypass valve is not integrated into the intake plumbing between the compressor outlet and throttle body * The outlet plumbing for the bypass valve is too small or restrictive * The turbo is too big for the application
