AIR BYPASS CONTROL METHOD FOR COMPRESSOR OF TWO-SHAFT TWO-CIRCUIT GAS- TURBINE ENGINE Russian patent published in 1997 - IPC

FIELD: mechanical engineering; gas-turbine engines; stalling and surging protection. SUBSTANCE: order to close valves is formed when operating conditions change from low gas to maximum gas. At low gas conditions 1=1, 1₂= 0,1₄= 1 and OR unit 6 forms signal for opening air bypass valve according to logic of its operation. Air bypass valves are open (1_abv= 1) and output of unit 6 is direct connected with air bypass valve controls. By signal 1_abv= 1 output of unit 6 is connected with controls of air bypass valve and output of unit 9 is disconnected from controls of air bypass valves by means of switch 11. As operating conditions change to increase, 1 changes to 0, condition 1₁= 1₂= 1₄= 0, is fulfilled and air bypass valves close. By signal for closing (1_abv), control of air bypass valves is effected through unit 9. Output of unit 6 is connected with one of inputs of unit 9, and signal to open the valves passes from output of unit 9 connected to controls of air bypass valves through unit 11 by signal 1_abv= 0.. When h_a1 is reduced by value Δn_ap from initial value, order is formed to open air bypass valves. At maximum gas conditions 1₁= 1₂= 1₄= 0 air bypass valves are closed, and switch 10 provides control of air bypass valves from unit 9. When α_pch is shifted from maximum to low gas, signal 1₃= 1 appears, and unit 6 forms signal to open air bypass valves. Simultaneously conditions are changed for decrease, signal 1₃= 1 appears and order for to open air bypass valves is formed. Air bypass valves are opened by order from unit 9 connected to unit 11 by order 1_abv= 0. EFFECT: improved reliability. 2 dwg