Method for fuel flow determination and improving thermal efficiency in a fossil-fired power plant

Claim 1

A method for improving thermal efficiency of a fossil-fired power plant system comprising a boiler cycle in which a fossil fuel is supplied at a flow rate to be combusted to heat a working fluid, the combustion of the fuel producing effluents in an exhaust, and a turbine cycle in which the working fluid does work, the method comprising the following steps: analyzing the fuel for its dry base chemical composition, measuring at a gas exit boundary of the power plant system, in the exhaust of the combustion process, the temperature, concentrations of CO 2 and H 2 O effluents to an accuracy of at least ±0.5% molar, and concentrations of O 2 with an accuracy at least comparable to zirconium oxide detection, measuring the net energy deposition to the working fluid being heated by the combustion process, determining, independently of the fuel flow rate, a combustion efficiency based on a stoichiometric balance of a combustion equation and a boiler absorption efficiency based on determination of non-stack losses, combining the combustion efficiency and the boiler absorption efficiency to obtain a boiler efficiency, determining an efficiency of the turbine cycle, combining the boiler efficiency and the turbine cycle efficiency to obtain the power plant system efficiency, determining in response to obtaining the boiler efficiency and the power plant system efficiency if either is degraded from predetermined parameters, and adjusting operation of the system to improve its boiler efficiency and/or its system efficiency.

Claim 2

A method for improving thermal efficiency of a fossil-fired power plant system comprising a boiler cycle in which a fossil fuel is supplied at a flow rate to be combusted to heat a working fluid, the combustion of the fuel producing effluents in an exhaust, and a turbine cycle in which the working fluid does work, the method comprising the following steps: analyzing the fuel for its dry base chemical composition, measuring at a gas exit boundary of the power plant system, in the exhaust of the combustion process, the temperature, concentrations of CO 2 and H 2 O effluents to an accuracy of at least ±0.5% molar, and concentrations of O 2 with an accuracy at least comparable to zirconium oxide detection, measuring the net energy deposition to the working fluid being heated by the combustion process, determining, independently of the fuel flow rate, a combustion efficiency based on a stoichiometric balance of a combustion equation and a boiler absorption efficiency based on determination of non-stack losses, combining the combustion efficiency and the boiler absorption efficiency to obtain a boiler efficiency, determining an efficiency of the turbine cycle, combining the boiler efficiency and the turbine cycle efficiency to obtain the power plant system efficiency, determining in response to obtaining the boiler efficiency and the power plant system efficiency if either is degraded from predetermined parameters, and adjusting operation of the system to improve its boiler efficiency and/or its system efficiency.

Claim 7

A method for determining and improving thermal efficiency of a fossil-fired power plant system comprising a boiler cycle in which a fossil fuel is supplied at a flow rate to be combusted to heat a working fluid, the combustion of the fuel producing effluents in an exhaust, and a turbine cycle in which the working fluid does work, comprising the following steps: analyzing the fuel for its dry base chemical composition, measuring in the exhaust of the combustion process at the gas exit boundary of the power plant system the temperature, concentrations of CO 2 and H 2 O effluents to at least an accuracy of ±0.5% molar by utilizing an emissions spectral radiometer, and concentrations of O 2 with an accuracy at least comparable to zirconium oxide detection, measuring the net energy deposition to the working fluid being heated by the combustion process, determining, independently of the fuel mass flow rate, both a combustion efficiency as based on a stoichiometric balance of a combustion equation and a boiler absorption efficiency based on determination of non-stack losses, combining combustion efficiency and boiler absorption efficiency to obtain the boiler efficiency, repetitiously adjusting assumed water concentration in the fuel until consistency is obtained between the measured CO 2 and H 2 O effluents and those determined by stoichiometries based on the chemical concentration of the fuel for establishing validity for a calculated fuel mass flow rate and boiler efficiency, determining whether degradations from predetermined parameters are occurring in the fuel-air mixing equipment, the differential boiler fuel flows, the heat content of the fuel, and whether stack losses are increasing by detecting decreases in iterative combustion efficiency calculations, determining whether degradations from predetermined parameters are occurring due to increased radiation and convection losses, heat content remaining in the coal rejects, heat exchanger water/steam leaks, heat exchanger loss of effectiveness, and increases in other non-stack losses by detecting decreases in iterative boiler absorption efficiency calculations, and adjusting operation of the power plant system to improve its thermal efficiency and/or its system efficiency.

Claim 8

A method for determining and improving thermal efficiency of a fossil-fired power plant system comprising a boiler cycle in which a fossil fuel is supplied at a flow rate to be combusted to heat a working fluid, the combustion of the fuel producing effluents in an exhaust, and a turbine cycle in which the working fluid does work, comprising the following steps: analyzing the fuel for its dry base chemical composition, measuring in the exhaust of the combustion process at the gas exit boundary of the power plant system the temperature, concentrations of CO 2 and H 2 O effluents to at least an accuracy of ±0.5% molar by utilizing an emissions spectral radiometer, and concentrations of O 2 with an accuracy at least comparable to zirconium oxide detection, measuring the net energy deposition to the working fluid being heated by the combustion process, determining, independently of the fuel mass flow rate, both a combustion efficiency as based on a stoichiometric balance of a combustion equation and a boiler absorption efficiency based on determination of non-stack losses, combining combustion efficiency and boiler absorption efficiency to obtain the boiler efficiency, repetitiously adjusting assumed water concentration in the fuel until consistency is obtained between the measured CO 2 and H 2 O effluents and those determined by stoichiometries based on the chemical concentration of the fuel for establishing validity for a calculated fuel mass flow rate and boiler efficiency, determining whether degradations from predetermined parameters are occurring in the fuel-air mixing equipment, the differential boiler fuel flows, the heat content of the fuel, and whether stack losses are increasing by detecting decreases in iterative combustion efficiency calculations, determining whether degradations from predetermined parameters are occurring due to increased radiation and convection losses, heat content remaining in the coal rejects, heat exchanger water/steam leaks, heat exchanger loss of effectiveness, and increases in other non-stack losses by detecting decreases in iterative boiler absorption efficiency calculations, and adjusting operation of the power plant system to improve its thermal efficiency and/or its system efficiency.

Claim 9

A method for determining the fuel flow rate and pollutant flow rates of a fossil-fired steam generator system having a working fluid by monitoring the operation of the steam generator system and making calculations which are derived from data obtained from the analysis of the chemical composition of the dry component of the fuel, the concentrations of the common pollutants produced from combustion, and the concentrations of CO 2 and superheated water produced from combustion and the fuel, comprising analyzing the fuel for its dry base chemical composition, measuring at a gas exit boundary of the steam generator system in the exhaust of the combustion process the temperature, concentrations of CO 2 and H 2 O effluents to an accuracy of at least ±0.5% molar, and concentrations of O 2 with an accuracy at least comparable to zirconium oxide detection, measuring the net energy deposition to the working fluid being heated by the combustion process, calculating, independently of the fuel flow rate, a combustion efficiency based on the stoichiometric balance of a combustion equation and a boiler absorption efficiency based on determination of non-stack losses, combining the combustion efficiency and the boiler absorption efficiency to obtain a boiler efficiency, and determining the fuel flow rate from the boiler efficiency.

Claim 10

A method for determining the fuel flow rate and pollutant flow rates of a fossil-fired steam generator system having a working fluid by monitoring the operation of the steam generator system and making calculations which are derived from data obtained from the analysis of the chemical composition of the dry component of the fuel, the concentrations of the common pollutants produced from combustion, and the concentrations of CO 2 and superheated water produced from combustion and the fuel, comprising analyzing the fuel for its dry base chemical composition, measuring at a gas exit boundary of the steam generator system in the exhaust of the combustion process the temperature, concentrations of CO 2 and H 2 O effluents to an accuracy of at least ±0.5% molar, and concentrations of O 2 with an accuracy at least comparable to zirconium oxide detection, measuring the net energy deposition to the working fluid being heated by the combustion process, calculating, independently of the fuel flow rate, a combustion efficiency based on the stoichiometric balance of a combustion equation and a boiler absorption efficiency based on determination of non-stack losses, combining the combustion efficiency and the boiler absorption efficiency to obtain a boiler efficiency, and determining the fuel flow rate from the boiler efficiency.

Claim 18

A method for determining fuel flow, pollutant flow rates, and improving thermal efficiency of a fossil-fired steam generator power plant system comprising a boiler cycle in which a fossil fuel is supplied at a flow rate to be combusted to heat a working fluid, the combustion of the fuel producing effluents in an exhaust, and a turbine cycle in which the working fluid does work, the method comprising the following steps: analyzing the fuel for its dry base chemical composition, measuring at a gas exit boundary of the power plant system, in the exhaust, the temperature, the concentrations of CO 2 and H 2 O effluents to a predetermined accuracy, and O 2 with an accuracy at least comparable to zirconium oxide detection, measuring the net energy deposition to the working fluid being heated by the combustion process, determining, independently of the fuel flow rate, a combustion efficiency based on a stoichiometric balance of a combustion equation and a boiler absorption efficiency based on determination of non-stack losses, combining the combustion efficiency and the boiler absorption efficiency to obtain a boiler efficiency, determining an efficiency of the turbine cycle, combining the boiler efficiency and the turbine cycle efficiency to obtain the power plant system efficiency, determining in response to obtaining the boiler efficiency and the power plant system efficiency if either is degraded from predetermined parameters, and adjusting operation of the power plant system to improve its boiler efficiency and/or its system efficiency.

Claim 19

A method for determining fuel flow, pollutant flow rates, and improving thermal efficiency of a fossil-fired steam generator power plant system comprising a boiler cycle in which a fossil fuel is supplied at a flow rate to be combusted to heat a working fluid, the combustion of the fuel producing effluents in an exhaust, and a turbine cycle in which the working fluid does work, the method comprising the following steps: analyzing the fuel for its dry base chemical composition, measuring at a gas exit boundary of the power plant system, in the exhaust, the temperature, the concentrations of CO 2 and H 2 O effluents to a predetermined accuracy, and O 2 with an accuracy at least comparable to zirconium oxide detection, measuring the net energy deposition to the working fluid being heated by the combustion process, determining, independently of the fuel flow rate, a combustion efficiency based on a stoichiometric balance of a combustion equation and a boiler absorption efficiency based on determination of non-stack losses, combining the combustion efficiency and the boiler absorption efficiency to obtain a boiler efficiency, determining an efficiency of the turbine cycle, combining the boiler efficiency and the turbine cycle efficiency to obtain the power plant system efficiency, determining in response to obtaining the boiler efficiency and the power plant system efficiency if either is degraded from predetermined parameters, and adjusting operation of the power plant system to improve its boiler efficiency and/or its system efficiency.