Rapid transient response chemical energy power plant apparatus and method
AssigneeThe Garrett Corporation
InventorDavid A. Bailey
Life of this patent
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Abstract
A chemical energy power plant includes control of steam temperature to prevent turbine damage while allowing throttling of the power output level and rapid response to commands for changed power output level.
Claims23
Power plant apparatus comprising:
- reaction chamber means for containing a reactive metallic fuel;
- boiler tube means in association with said reaction chamber means defining an inlet, an outlet, and being disposed in heat receiving relationship with said metallic fuel;
- phase change liquid working fluid source means for supplying said liquid working fluid pressurized to said inlet, first feed rate control valve means for selectively regulating the rate of supply of said working fluid to said inlet;
- conduit means for communicating the vapor of said pressurized working fluid from said outlet to a vapor pressure expanding motor;
- attemperating means for communicating liquid working fluid from said source thereof to said conduit;
- and second feed rate control valve means for selectively regulating the rate of communication of said liquid attemperating working fluid to said conduit, reactant source means for supplying an exothermically reactive reactant to said reaction chamber means, and third reactant feed rate control valve means for selectively regulating the rate of supply of said reactant to said reaction chamber, first sensor means for producing a first signal indicative of the power output of said vapor pressure expanding motor, second sensor means for producing a second signal analogous to temperature of pressurized vapor flowing via said conduit to said expanding motor, and third sensor means for producing a third signal analogous to temperature of said metallic fuel, control means for receiving said first, second, and third signals and providing respective fourth, fifth, and sixth control signals individually to said first, second, and third control valve means for selectively variably opening and closing the latter, wherein said control means comprises first summation means for receiving said fourth and said fifth control signals and producing a seventh signal analogous to a weighted summation thereof, and multiplier means for receiving said seventh signal along with an eight signal indicative of an error value between said third signal and a selected value therefor and providing the product of said seventh and eighth signals as a ninth signal productive of said sixth control signal.
Control apparatus for a chemical energy power plant comprising:
- first means for sensing a shaft power output of said power plant and producing a respective signal;
- second means for sensing a temperature of pressurized vapor supply to a vapor pressure expanding motor producing said shaft power output and producing a respective signal;
- third means for sensing a temperature analogous to reaction temperature of a metallic fuel mass of said power plant and producing a respective signal;
- first control means receiving said first signal and producing a first command of liquid working fluid supply to a vaporizer of said power plant;
- second control means receiving said second signal and producing a second command of liquid working fluid supply to attemperate said pressurized vapor supply to said vapor pressure expanding motor;
- third control means receiving said first command and said second command along with said third signal to produce a third command of reactant supply to said metallic fuel mass.
The method of operating a chemical energy power plant comprising a mass of metallic fuel, a supply of reactant exothermically reacting with said metallic fuel to produce heat, a boiler tube in heat receiving relation with said metallic fuel, a source of working liquid communicating with said boiler tube to produce pressurized vapor, and a vapor pressure expanding motor receiving said pressurized vapor and producing shaft power;
- said method comprising the steps of:
- maintaining said mass of metallic fuel in a molten reactive state at a substantially constant elevated temperature;
- attemperating said pressurized vapor flowing to said motor by supply of working liquid thereto to maintain a substantially constant temperature of said pressurized vapor;
- and
- contemporaneously varying the power output of said power plant by varying the rate of communication of working liquid with said boiler tube.
The method of control of a chemical energy power system comprising a mass of metallic fuel, a supply of reactant exothermically reacting with said metallic fuel to produce heat, a boiler tube in heat receiving relation with said metallic fuel, a source of working liquid communicating with said boiler tube to produce pressurized vapor, and a vapor pressure expanding motor receiving said pressurized vapor and producing shaft power;
- said method comprising the steps of:
- regulating the rate of communication of said working liquid with said boiler tube in accord with a power command signal;
- regulating the temperature of said pressurized vapor flowing to said vapor pressure expanding motor to a substantially constant value by attemperation with working liquid;
- regulating the rate of reaction of said reactant with said metallic fuel in accord with a weighted summation of working liquid flow to said motor via said boiler and via attemperation;
- and
- further regulating the rate of reaction of said reactant with said metallic fuel to maintain a substantially constant elevated temperature thereof.
The method of controlling a chemical energy power plant having a mass of molten metallic fuel exothermically reacting with a reactant so as to facilitate rapid transient response to a request for a changed power output level, said method comprising the steps of:
- maintaining the temperature of said molten fuel mass at a substantially constant level irrespective of power output level, maintaining the temperature of pressurized working fluid vapor generated by heat transfer from said fuel mass and communicating with a vapor pressure expanding motor also substantially constant irrespective of power output level, establishing a direct relationship between a quantity of crust of reaction products on a boiler tube of said power plant and said power output level, and utilizing the heat of fusion of said crust increasing with increasing power output level to thermally drive said power plant toward said increased power output level.
Control apparatus for a chemical energy power plant including a reaction chamber providing a flow of pressurized working fluid vapor, a mass of molten exothermically reactive metallic fuel within said reaction chamber, a vapor pressure expanding motor receiving said flow of pressurized working fluid vapor to produce shaft power, and means for attemperating said pressurized working fluid vapor intermediate said reaction chamber and said motor, said control apparatus comprising:
- first means providing a first signal indicative of a commanded power output level of said power plant;
- second means in association with said first means providing a second signal indicative of an actual power output level of said power plant;
- third means deriving from said first signal and said second signal a first error signal indicative of required change in power plant power output level;
- first proportional-plus-integral means providing in combination a first P-plus-I signal comprising a weighted value of said first error signal plus a time integral value thereof;
- corrective adder means adding to said first P-plus-I signal a time variant weighted value of said first signal to provide a corrected P-plus-I signal;
- sign maintaining squaring means receiving said corrected P-plus-I signal as a value x and producing a first output signal having the value of x multiplied by the absolute value of x, (x.multidot..vertline.x.vertline.);
- means for receiving the first output signal (x.multidot..vertline.x.vertline.) and responsively producing a selectively valued and limited signal, F.sub.W ;
- first valve means for receiving the signal F.sub.W and regulating the flow rate of pressurized working fluid vapor from said reaction chamber in accord therewith;
- fourth means providing a fourth signal indicative of a selected temperature of said pressurized working fluid vapor flow to said motor;
- fifth means providing a fifth signal indicative of actual temperature of said pressurized working fluid vapor flow to said motor;
- sixth means deriving from said fourth signal and said fifth signal a second error signal indicative of required change in temperature of said pressurized working fluid vapor flow to said motor;
- second proportional-plus-integral means providing in combination a second P-plus-I signal comprising a weighted value of said second error signal plus a time integral value thereof;
- inverting means receiving said second P-plus-I signal as a value x and producing a second output signal having the value of negative x, (-x);
- means for receiving the second output signal and responsively producing a selectively limited signal, ATEMP;
- second valve means for regulating an attemperating flow of liquid working fluid to said pressurized working fluid vapor intermediate said reaction chamber and said motor to effect said attemperation in accord with said ATEMP signal;
- seventh means providing a seventh signal indicative of a selected temperature of said molten metallic fuel;
- eighth means providing an eight signal indicative of actual temperature of said molten fuel;
- ninth means deriving from said seventh signal and said eight signal a third error signal indicative of required change in temperature of said molten fuel;
- third proportional-plus-integral means providing in combination a third P-plus-I signal comprising a weighted value of said third error signal plus a time integral value thereof;
- summation means receiving both said F.sub.W signal and said ATEMP signal and providing a weighted summation signal thereof designated .SIGMA.H.sub.2 O;
- multiplier means for receiving both said third P-plus-I signal and said .SIGMA.H.sub.2 O signal and providing a third output signal having a value substantially equal to the product of said received signals;
- means for receiving said third output signal and responsively producing a selectively valued and limited signal, REAC;
- third valve means for regulating a flow of exothermically reactive reactant to said metallic fuel in response to said REAC signal.
Dependencies are inferred from the claim text.