Stall detector for a gas turbine engine

Stall detector for an axial flow gas turbine engine having a compressor, burner and turbine, in combination with a fuel control having a fuel metering valve regulating the flow of fuel to the burner and independent coordinating means providing a schedule for the minimum fuel flow metered by said fuel metering valve, said stall detector including means responsive to said minimum fuel flow schedule for producing a first signal whenever said fuel control is on the minimum fuel flow schedule, means responsive to the rate of change of pressure of said compressor for producing a second signal when the rate of pressure decay exceeds a predetermined value and means responsive to both said first signal and said second signal for producing a third signal indicative of stall solely when said first signal and said second signal are received.

Stall detector for an axial flow gas turbine engine having a compressor, burner and turbine, in combination with a fuel control having a fuel metering valve regulating the flow of fuel to the burner and independent coordinating means providing a schedule for the minimum fuel flow metered by said fuel metering valve, said stall detector including means responsive to said minimum fuel flow schedule for producing a first signal whenever said fuel control is on the minimum fuel flow schedule, means for sensing the temperature of the turbine, a second signal, a comparator means responsive to said turbine temperature comparing its value with a reference value to produce a second signal indicative of an abnormally high temperature and gate means responsive to both said first signal and said second signal for producing a third signal indicative of stall solely when said first signal and said second signal are received by said gate means.

Stall detector for an axial flow gas turbine engine having a compressor, burner and turbine, in combination with a fuel control having a fuel metering valve regulating the flow of fuel to the burner and independent coordinating means providing a schedule for the minimum fuel flow metered by said fuel metering valve, and independent coordinating means providing a schedule for engine acceleration by limiting the fuel metering valve, said stall detector including means responsive to said minimum fuel flow schedule for producing a first signal whenever said fuel control is on the minimum fuel flow schedule, means responsive to said acceleration schedule for producing a second signal when the fuel control is operating on or in proximity to the acceleration schedule and means responsive to both said first signal and said second signal for producing a third signal indicative of stall solely when said first signal and said second signal are received.

The method of detecting stall in a gas turbine axial flow engine which includes a fuel control that schedules engine operation and particularly the minimum fuel flow comprising the steps of:

• measuring the fuel control schedule so as to produce an output signal whenever the fuel metered to the engine is at the minimum value,
• measuring a parameter other than the minimum flow schedule which parameter would be abnormal relative to engine operation when the fuel control is on the minimum flow schedule to produce an output signal when that parameter is abnormal under those circumstances,
• combining both the output signals obtained in the steps of measuring to produce an output signal solely when both signals are present to indicate a stall condition which signal can be used as a warning or to initiate stall corrective action.

The method of detecting stall in a gas turbine axial flow engine which includes a fuel control that schedules engine operation and particularly the minimum fuel flow comprising the steps of:

• measuring the fuel control schedule so as to produce an output signal whenever the fuel metered to the engine is at a minimum value,
• measuring the air pressure at or in proximity to the compressor so as to produce an output signal whenever its decay rate of change reaches a predetermined value,
• combining both the output signals obtained in the steps of measuring to produce an output signal indicative of a stall condition which signal can be used as a warning or to initiate stall corrective action.

The method of detecting stall in a gas turbine axial flow engine which includes a fuel control that schedules engine operation and particularly the minimum fuel flow comprising the steps of:

• measuring the fuel control schedule so as to produce an output signal whenever the fuel metered to the engine is at the minimum value,
• measuring the temperature at or in proximity to the turbine so as to produce an output signal whenever its value reaches an abnormally high predetermined value,
• combining both the output signals obtained in the steps of measuring to produce an output signal indicative of a stall condition which signal can be used as a warning or to initiate stall corrective action.

The method of detecting stall in a gas turbine axial flow engine which includes a fuel control that schedules engine acceleration operation and the minimum fuel flow comprising the steps of:

• measuring the fuel control schedule so as to produce an output signal whenever the fuel metered to the engine is at the minimum value,
• measuring the fuel control schedule so as to produce an output signal whenever the fuel control is scheduling acceleration,
• combining both the output signals obtained in the steps of measuring to produce an output signal solely when both signal are present which indicates a stall condition which signal can be used as a warning or to initiate stall corrective action.