Fuel control for a gas turbine having auxiliary air bleed

Claim 2

A control for regulating the rate of fuel flow to the burners of a gas turbine having a compressor discharge section and having a valved bleed passage communicating with said compressor discharge section to deliver a variable amount of air from said compressor discharge section for auxiliary use, said control comprising a fuel regulating element displaceable to different positions to control the rate of fuel flow to said burners, and means for detecting the weighted difference between the pressure P3 in said compressor discharge section and the pressure PB in said bleed passage and for causing said fuel regulating element to be displaced as a predetermined function of changes in said weighted difference.

Claim 3

A control as defined in claim 1 in which said function is linear.

Claim 4

A control as defined in claim 1 in which said means cause said displacement to vary according to changes in the relationship P3K - PB(K - 1) where K is a constant.

Claim 5

A control as defined in claim 1 in which said means comprise a first chamber communicating with said compressor discharge section, a second chamber communicating with said bleed passage, each of said chambers having a wall which is moved in response to pressure changes in the respective chambers, and means connected to said walls and operable to cause displacement of said fuel regulating element in response to movement of said walls.

Claim 6

A control as defined in claim 4 in which said walls are located so as to cause movement of said connected means in one direction in response to an increase in pressure in one of said chambers and in the opposite direction in response to an increase in pressure in the other of said chambers.

Claim 7

A control as defined in claim 5 in which said walls have different effective areas against which the respective pressures act.

Claim 8

The combination of, a gas turbine having burners, and a control having a fuel regulating element displaceable to different positions to control the rate of fuel flow to said burners, said turbine having a compressor discharge section and having a valved bleed passage communicating with said compressor discharge section to deliver a variable amount of air from said compressor discharge section for auxiliary use, the improvement in said combination comprising, means for detecting the weighted difference between the pressure P3 in said compressor discharge section and the pressure PB in said bleed passage and for causing said fuel regulating element to be displaced as a predetermined function of changes in said weighted difference, said means comprising first and second chambers communicating with said compressor discharge section and said bleed passage, respectively, said first chamber having a wall which is movable in one direction in response to an increase in pressure in said compressor discharge section, said second chamber havIng a wall which is movable in said one direction in response to a decrease in pressure in said bleed passage, and means connected to said walls and operable to cause displacement of said fuel regulating element in response to movement of said walls.

Claim 9

The combination of, a gas turbine having burners, and a control having a fuel regulating element displaceable to different positions to control the rate of fuel flow to said burners, said turbine having a compressor discharge section and having a valved bleed passage communicating with said compressor discharge section to deliver a variable amount of air from said compressor discharge section for auxiliary use, the improvement in said combination comprising, means for detecting the weighted difference between the pressure P3 in said compressor discharge section and the pressure PB in said bleed passage and for causing said fuel regulating element to be displaced as a predetermined function of changes in said weighted difference, said means comprising first and second chambers communicating with said compressor discharge section and said bleed passage, respectively, said first chamber having a wall which is movable in one direction in response to an increase in pressure in said compressor discharge section, said second chamber havIng a wall which is movable in said one direction in response to a decrease in pressure in said bleed passage, and means connected to said walls and operable to cause displacement of said fuel regulating element in response to movement of said walls.

Claim 10

The combination of, a gas turbine having burners, and a control having a fuel regulating element displaceable to different positions to control the rate of fuel flow to said burners, said turbine having a compressor discharge section and having a valved bleed passage communicating with said compressor discharge section to deliver a variable amount of air from said compressor discharge section for auxiliary use, the improvement in said combination comprising, means for sensing the pressure in said compressor discharge section and the pressure in said bleed passage and for causing displacement of said fuel regulating element in response to a change in either pressure, said means comprising first and second chambers communicating with said compressor discharge section and said bleed passage, respectively, said first chamber having a wall which is movable in one direction in response to an increase in pressure in said compressor discharge section, said second chamber having a wall which is movable in said one direction in response to a decrease in pressure in said bleed passage, and means connected to said walls and operable to cause displacement of said fuel regulating element in response to movement of said walls.

Claim 11

The combination of, a gas turbine having burners, and a control having a fuel regulating element displaceable to different positions to control the rate of fuel flow to said burners, said turbine having a compressor discharge section and having a valved bleed passage communicating with said compressor discharge section to deliver a variable amount of air from said compressor discharge section for auxiliary use, the improvement in said combination comprising, means for sensing the pressure in said compressor discharge section and the pressure in said bleed passage and for causing displacement of said fuel regulating element in response to a change in either pressure, said means comprising first and second chambers communicating with said compressor discharge section and said bleed passage, respectively, said first chamber having a wall which is movable in one direction in response to an increase in pressure in said compressor discharge section, said second chamber having a wall which is movable in said one direction in response to a decrease in pressure in said bleed passage, and means connected to said walls and operable to cause displacement of said fuel regulating element in response to movement of said walls.

Claim 12

A control for regulating the rate of fuel flow to the burners of a gas turbine having a compressor discharge section and having a valved bleed passage communicating with said compressor discharge section to deliver a variable amount of air from said compressor discharge section for auxiliary use, said control comprising a fuel regulatingg element displaceable to different positions to control the rate of fuel flow to said burners, means for detecting the pressure P3 in said compressor discharge section and the pressure PB in said bleed passage and for causing displacement D of said fuel regulating element in response to a change in either pressure, said means causing said displacement D to change as a linear function of changes in PB/P3 whereby a given change in PB/P3 will produce a constant percentage change in D regardless of the value of P3.

Claim 13

A control for regulating the rate of fuel flow to the burners of a gas turbine having a compressor discharge section and having a valved bleed passage communicating with said compressor discharge section to deliver a variable amount of air from said compressor discharge section for auxiliary use, said control comprising a fuel regulatingg element displaceable to different positions to control the rate of fuel flow to said burners, means for detecting the pressure P3 in said compressor discharge section and the pressure PB in said bleed passage and for causing displacement D of said fuel regulating element in response to a change in either pressure, said means causing said displacement D to change as a linear function of changes in PB/P3 whereby a given change in PB/P3 will produce a constant percentage change in D regardless of the value of P3.