What causes compressor to surge?
Surge occurs when there is no forward flow of gas through the compressor and a reversal of flow occurs. The gas that is being compressed gets pushed backward through the centrifugal compressor. When this surge (flow reversal) occurs, which can happen in milliseconds, the rotor is affected.
What is surge in compressor How do you detect and control it?
Essentially, energy accumulated in the compressed gas becomes greater than the energy level the rotating impeller of the compressor can sustain, and, as a result, the gas rapidly expands in an abnormal direction back through the compressor. …
What happens during compressor surge?
So, the compressor loses the ability to maintain the peak head when surge occurs and the entire system becomes unstable. A collection of surge points during varying compressor speed or varying inlet gas angle is fitted as surge line. In normal conditions, the compressor operates in the right side of the surge line.
What is stalling and surging?
In elementary terms, stall is a disturbance of the flow in the tangential direction, while surge is a disturbance in the axial direction. During stalled operation, the average flow rate through the compressor is steady, but during surge, the flow rate will pulse—sometimes so violently that reversed flow is induced.
What is surging choking and stalling?
Choking or stonewall The choking occurs in the compressor which operates at a low discharge pressure and maximum flow rate. Surge – Occur minimum flow rate, choking – at maximum flow rate. Stall – Localized fluid separation, Surge – complete fluid separation.
What is surging in pump?
Ltd. Pump surging is something similar to Pump Cavitation. i.e. When the suction side of the pump doesnot have enough liquid to suck then the temperature of the pump will increase and results in vapor burst of the liquid present in the pump.
What is surging of turbocharger?
Turbocharger surging may be defined as a high pitch vibration of audible level coming from the blower end or compressor end of the turbocharger.
What is stonewalling in a compressor?
A stonewall or choked flow condition occurs when sonic velocity is reached at the exit of a compressor wheel. When this point is reached, flow through the compressor cannot be increased even with further increase in suction pressure.
What is slip in compressor?
From Wikipedia, the free encyclopedia. In turbomachinery, the slip factor is a measure of the fluid slip in the impeller of a compressor or a turbine, mostly a centrifugal machine. Fluid slip is the deviation in the angle at which the fluid leaves the impeller from the impeller’s blade/vane angle.
What are the damages due to compressor choking?
Prolonged operation of a compressor at its choke point can lead to damaging the compressor parts. Compressor choking is not particularly damaging to single-stage centrifugal compressors but can cause serious damage to the rotors and blades of multistage centrifugal and axial compressors.
What is Stonewall condition?
Compressor choke or stonewall is an unstable operating condition, which occurs when the compressor is operating at low discharge pressure and high f low rate. This leads to increased gas velocity in the compressor.
What is non dimensional flow?
The third and fourth non-dimensional groups are defined as ‘non-dimensional mass flow’ and ‘non-dimensional rotational speed’ respectively. When the valve is shut and the mass flow rate is zero, the pressure ratio will have some value. Figure 8.2 indicates a theoretical characteristics curve ABC for a constant speed.
What is an example of steady flow?
A steady flow device is any device that will have a continuous flow of material through it. Some examples of steady flow devices include pipes, nozzles, diffusers, and pumps. Because the nozzle changes the velocity of the water as it exits the hose, it will take a force to hold the nozzle in place.
What is the difference between steady and unsteady flow?
A steady flow is one in which the conditions of velocity, pressure, and cross–section may differ from point to point but do not change with time. If at any point in the fluid, the conditions change with time, the flow is described as unsteady.