US3922859A — Control system for a power producing unit

Claim 1

Independent Claim 186 words

In a control system for a power producing unit comprising a vapor generator and a turbine-generator supplied with vapor from said vapor generating unit, the combination comprising; a first means generating a first feed forward signal corresponding to the desired power output of the power producing unit, a second means responsive to said first feed forward signal generating a second feed forward signal proportional in value to said first feed forward signal modified by the difference between desired and actual power output of the power producing unit, a third means responsive to said second feed forward signal maintaining the rate of flow of vapor to the turbine proportional to said second feed forward signal, a fourth means responsive to said first feed forward signal maintaining the pressure of the vapor admitted to said turbine at a set point value varying in a first functional relationship to said first feed forward signal and a fifth means responsive to said first feed forward signal maintaining the pressure in said vapor generator at a set point value varying in a second functional relationship to said first feed forward signal.

Claim 2

Dependent Claim 186 words

In a control system for a power producing unit comprising a vapor generator and a turbine-generator supplied with vapor from said vapor generating unit, the combination comprising; a first means generating a first feed forward signal corresponding to the desired power output of the power producing unit, a second means responsive to said first feed forward signal generating a second feed forward signal proportional in value to said first feed forward signal modified by the difference between desired and actual power output of the power producing unit, a third means responsive to said second feed forward signal maintaining the rate of flow of vapor to the turbine proportional to said second feed forward signal, a fourth means responsive to said first feed forward signal maintaining the pressure of the vapor admitted to said turbine at a set point value varying in a first functional relationship to said first feed forward signal and a fifth means responsive to said first feed forward signal maintaining the pressure in said vapor generator at a set point value varying in a second functional relationship to said first feed forward signal.

Claim 3

Dependent Claim 37 words

In a control system as set forth in claim 1 wherein said fifth means includes means venting vapor from said vapor generator as required to inhibit the pressure in said Vapor generator from exceeding set point value.

Claim 4

Dependent Claim 60 words

In a control system as set forth in claim 1 wherein said vapor generator is provided with fuel and air supply means and wherein said fifth means includes means adjusting the rates of fuel and air supplied said vapor generator as required to maintain the pressure in said vapor generator in said second functional relationship to said first feed-forward signal.

Claim 5

Dependent Claim 59 words

In a control system as set forth in claim 1 wherein said fourth means includes manually adjustable means establishing an initial set point value, a final set point value and the desired rate of change in set point value with the magnitude of said first forward signal from said initial set point value to said final set point value.

Claim 6

Dependent Claim 131 words

In a control system as set forth in claim 1 wherein said vapor generator is provided with a primary superheater, a secondary super-heater and a control valve for regulating the flow of vapor from the primary to the secondary superheater and wherein said turbine is provided with admission valves for regulating the flow of vapor into said turbine and wherein said third means includes means adjusting said admission valves as required to maintain the rate of flow of vapor to the turbine proportional to said second feed forward signal and said fourth means includes means adjusting said control valve as required to maintain the pressure of the vapor on the inlet side of said admission valves at a set point value varying in functional relationship to said first feed forward signal.

Claim 7

Dependent Claim 150 words

In a start-up system for a power producing unit comprising a vapor generator provided with fuel and air supply means, a primary and a secondary superheater and a reheater, and a turbine-generator comprising a high pressure unit supplied vapor from said secondary superheater, a lower pressure unit supplied vapor from said reheater and a condenser condensing vapor discharged from said lower pressure unit, the combination comprising; means selecting the one of a plurality of measured conditions in said power producing unit having the greatest deviation from set point value generating a control signal varying in functional relationship with said deviation, means responsive to said control signal adjusting the rates of fuel and air supplied said vapor generator as required to maintain said selected one of the plurality of measured conditions at set point value and auxiliary instrumentalities maintaining the other of said plurality of measured conditions at set point values.

Claim 8

Dependent Claim 150 words

In a start-up system for a power producing unit comprising a vapor generator provided with fuel and air supply means, a primary and a secondary superheater and a reheater, and a turbine-generator comprising a high pressure unit supplied vapor from said secondary superheater, a lower pressure unit supplied vapor from said reheater and a condenser condensing vapor discharged from said lower pressure unit, the combination comprising; means selecting the one of a plurality of measured conditions in said power producing unit having the greatest deviation from set point value generating a control signal varying in functional relationship with said deviation, means responsive to said control signal adjusting the rates of fuel and air supplied said vapor generator as required to maintain said selected one of the plurality of measured conditions at set point value and auxiliary instrumentalities maintaining the other of said plurality of measured conditions at set point values.

Claim 9

Dependent Claim 97 words

In a start-up system as set forth in claim 6 wherein said vapor generator is provided with a vapor by-pass from the vapor inlet of said secondary superheater to said condenser, one of said plurality of conditions is the vapor pressure at the vapor outlet of said primary superheater and one of said auxiliary instrumentalities includes means responsive to the deviation in said vapor pressure above set point value and means responsive to said last named means adjusting the rate of flow of vapor through said vapor by-pass to reduce said vapor pressure to set point value.

Claim 10

Dependent Claim 103 words

In a start-up system as set forth in claim 6 wherein said vapor generator is provided with a vapor by-pass from the vapor inlet of said primary superheater to the vapor outlet of said secondary superheater, one of said plurality of conditions is the temperature of the vapor discharged from said secondary superheater and one of said auxiliary instrumentalities includes means responsive to the deviation in said vapor temperature above set point value, and means responsive to said last named means adjusting the rate of flow of vapor through said last named vapor by-pass to reduce said vapor temperature to set point value.

Claim 11

Dependent Claim 103 words

In a start-up system as set forth in claim 6 wherein said vapor generator is provided with a vapor by-pass from the vapor inlet of said primary superheater to the vapor outlet of said reheater, one of said plurality of conditions is the temperature or the vapor discharged from said reheater and one oF said auxiliary instrumentalities includes means responsive to the deviation in said reheated vapor temperature above set point value, and means responsive to said last named means adjusting the rate of flow of vapor through said last named vapor by-pass to reduce said reheated steam temperature to set point value.

Claim 12

Dependent Claim 79 words

In a start-up system as set forth in claim 6 wherein said vapor generator is provided with a valve in the vapor conduit between said primary and secondary superheaters and one of said auxiliary instrumentalities includes means responsive to the deviation in pressure of the vapor at the inlet to said high pressure turbine from set point value, and means responsive to said last named means adjusting said valve to maintain said last named pressure at set point value.

Claim 13

Dependent Claim 61 words

In a start-up control system as set forth in claim 8 wherein the set point value of the superheat steam is established by manually adjustable means establishing an initial set point value, a final set point value and the desired rate of change with time in set point value from said initial set point value to said final set point value.

Claim 14

Dependent Claim 73 words

In a start-up system as set forth in claim 6 wherein said plurality of measured conditions includes pressure of the vapor at the inlet to said high pressure turbine, temperature of the flue gas in said vapor generator between said secondary superheater and said reheater, pressure of the vapor is said vapor generator at the outlet of the primary superheater and temperature of the vapor at the inlet to said high pressure turbine.

Claim 15

Dependent Claim 95 words

In a start-up system as set forth in claim 6 wherein said one of a plurality of measured conditions is the temperature of the flue gas between said primary and secondary superheaters, means generating a feedforward signal varying in functional relationship with the energy demand from said power producing unit, means responsive to the temperature of the flue gas between said primary and secondary superheaters, and means under the joint control of said last two named means adjusting the fuel and air supplied said vapor generator to maintain said flue gas temperature at desired value.

Claim 16

Dependent Claim 121 words

In a control system as set forth in claim 6 wherein said one of a plurality of measured conditions is the temperature of the flue gas between said primary and secondary superheaters, means responsive to said temperature generating a control signal varying in accordance with changes in said flue gas temperature from set point, means generating a feedforward signal varying in functional relationship with the desired power output from said power producing unit, means responsive to said feedforward signal raising said set point in functional relationship with increases in said feedforward signal, and means responsive to said control signal adjusting the rates of fuel and air supplied said vapor generator as required to maintain said flue gas temperature at set point.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-12-01	1979-06-02	1979-12-02	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-12-01	1983-06-02	1983-12-02	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-12-01	1987-06-02	1987-12-02	$7700.00	Window Closed / Lapsed

Control system for a power producing unit

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