Valve which is meant to siphon off a portion of the flow from another system.
A heavy-duty gas turbine employs compressor bleed valves to protect the axial compressor during start-up and shutdown against stalling and surging conditions. These valves are typically only open during acceleration to rated speed and deceleration from rated speed. Newer heavy-duty gas turbine with complex combustion system arrangements designed to limit emission of harmful gases also employ the compressor bleed valves during very light loading to limit the amount of air entering the combustor.
Compressor bleed valves discharge into the gas turbine exhaust duct. Compressor bleed valves are generally closed during normal operation (with the previous exception) since "dumping" axial compressor discharge into the exhaust reduces efficiency (but it's MANDATORY during start-up and acceleration to protect the compressor!). Compressor bleed valves are generally either fully open or fully closed; they are not modulated.
Heavy-duty gas turbines also employ inlet bleed heat valves to recirculate a portion of the axial compressor discharge back to the inlet of the axial compressor for a variety of functions. One application uses them to heat the inlet air to prevent icing on the compressor inlet (appropriately called anti-icing protection); another application uses inlet bleed heat to protect the axial compressor when the IGVs (axial compressor Inlet Guide Vanes) are closed below the "normal" operating conditions ("normal" being before complicated combustion systems designed to limit exhaust emissions were invented).
Inlet bleed heat control valves are modulated to control the amount of air recirculated back to the axial compressor inlet. Recirculating axial compressor discharge back to the inlet is also inefficient, but is generally limited to approximately 5% of rated air flow through the compressor--and necessary to protect the compressor at low IGV angles. Inlet bleed heat valves are generally closed before the unit reaches rated load (except for anti-icing protection) and should be closed during rated power output (Base Load) operation (except for anti-icing protection).
Bleed air in gas turbine engines is compressed air taken from within the engine, after the compressor stage(s) and before the fuel is injected in the burner
Inefficiencies in the compressor of a gas turbine cycle increase the back-work ratio and decrease the thermal efficiency of the gas turbine cycle, since they increase the compressor work.
GT compressor pulsation ?
At exhaust valve opening, pressurised gas reduces pressure by moving across the turbine blades and out of the exhaust pipe, the momentum of the moving gas is tapped by the turbine blades producing torque on the turbine shaft.
Rotating axial compressor.
GT compressor pulsation ?
Air compressor alone consumes about 50 to 60 % of energy generated by a gas turbine..
This relationship is the reason advances in turbines and axial compressors often find their way cutaway showing an axi-centrifugal compressor gas turbine.
where can i get a pilot valve for gas air compressor
self sustaining speed is output of a turbine= input into compressor
a gas compressor is a device that increases pressure and reduces its volume
Compressor Inlet Temperature sensorfor a Gas turbine engine.