Fuel Type Recognition and/or Fuel Quantity Control and/or Air Volume Control

Abstract

Various embodiments include a method for estimating a flow value for fuels of different compositions supplied to a combustion device using a mass flow sensor. An example method includes: recording a first temperature of the fuel using a first resistor element; determining a compensable value with a heat output signal of a heating element; and estimating a flow value for the fuel supply by compensation of the value compensable as a function of the first temperature and/or as a function of the fuel composition and/or as a function of the fuel gas composition on the basis of at least one saved mapping rule dependent on the first temperature and/or on the fuel composition and/or on the fuel gas composition and on the basis of a calibration characteristic curve saved for a reference gas.

1 . A method for estimating a flow value for fuels of different compositions supplied to a combustion device via a fuel supply channel, wherein the combustion device comprises a mass flow sensor in fluid connection with the fuel, the method comprising:
 recording a first temperature signal indicating a first temperature of the fuel using a first resistor element of the mass flow sensor;   processing the first temperature signal to yield a first temperature;   determining a compensable value by recording a heat output signal indicating a heat output of a heating element of the mass flow sensor;   processing the heat output signal to yield a heat output;   determining the compensable value as heat output; and   estimating a flow value for the fuel supply by compensation of the value compensable as of a function the first temperature and/or as a function of the fuel composition and/or as a function of the fuel gas composition on the basis of at least one saved mapping rule dependent on the first temperature and/or on the fuel composition and/or on the fuel gas composition and on the basis of a calibration characteristic curve saved for a reference gas.   
     
     
         2 . The method as claimed in  claim 1 , wherein:
 the combustion device comprises a closed- and/or open-loop control unit and a plurality of first mapping rules for selectable fuels and dependent on the first temperature and a plurality of second mapping rules for selectable fuels and dependent on the first temperature are saved in the closed- and/or open-loop control unit, the method comprising:   establishing a plurality of first estimated flow values for the fuel supply by compensating the heat output as a function of the first temperature and/or as a function of the fuel composition and/or as a function of the fuel gas composition, on the basis of at least one mapping rule of the plurality of first, saved mapping rules and saved a first, calibration characteristic curve;   recording a second temperature signal and/or a third temperature signal;   processing the second temperature signal to yield a second temperature and/or the third temperature signal to yield a third temperature;   determining the temperature difference between two different temperatures selected from: the first temperature, the second temperature, and the third temperature;   establishing a plurality of second estimated flow values supply by compensating for the fuel the temperature difference as a function of the first temperature and/or as a function of the fuel composition and/or as a function of the fuel gas composition, on the basis of at least one mapping rule of the plurality of second, saved mapping rules and a second, saved calibration characteristic curve; and   estimating the type of fuel on the basis of the plurality of first estimated flow values and the plurality of second estimated flow values.   
     
     
         3 . The method as claimed in  claim 2 , the method comprising:
 forming distances between flow values of the plurality of first estimated flow values and the plurality of second estimated flow values;   selecting the smallest distance from the distances formed; and   estimating the type of fuel by assigning the smallest distance to a fuel.   
     
     
         4 . The method as claimed in  claim 2 , wherein a plurality of third mapping rules for selectable fuels and dependent on the first temperature are saved in the closed- and/or open-loop control unit, the method comprising:
 recording a fourth temperature signal indicating a fourth temperature of the fuel on the basis of a fourth resistor element of the mass flow sensor, wherein the fourth resistor element is different from the first resistor element and from the second resistor element and wherein the fourth resistor element is arranged opposite the second resistor element;   processing the fourth temperature signal to yield a fourth temperature;   calculating a second temperature difference between two different temperatures, selected from: the first temperature, the second temperature, and the fourth temperature;   establishing a plurality of third estimated flow values for the fuel supply by compensating the second temperature difference as a function of the first temperature and/or as a function of the fuel composition and/or as a function of the fuel gas composition, on the basis of at least one mapping rule of the plurality of third, saved mapping rules and on the basis of a third, saved calibration characteristic curve; and   estimating the type of fuel on the basis of the plurality of first estimated flow values and on the basis of the plurality of second estimated flow values and/or on the basis of the basis of the plurality of third estimated flow values.   
     
     
         5 . The method as claimed in  claim 4 , the method comprising:
 forming first distances between flow values of the plurality of first estimated flow values and the plurality of second estimated flow values;   forming first squared distances by squaring the first distances;   forming second distances between flow values of the plurality of first estimated flow values and the plurality of third estimated flow values;   forming second squared distances by squaring the second distances;   forming third distances between flow values of the plurality of second estimated flow values and the plurality of third estimated flow values;   forming third squared distances by squaring the third distances;   forming sum values by summing in each case a first squared distance selected from the first squared distances formed, in each case a second squared distance selected from the second squared distances formed and in each case a third squared distance selected from the third squared distances formed;   selecting the smallest sum value from the sum values formed; and   estimating the type of fuel by assigning the smallest sum value to a fuel.   
     
     
         6 . The method as claimed in  claim 2 , the method comprising selecting a value as a measure of a flow of the fuel from the plurality of first estimated flow values and from the plurality of second estimated flow values. 
     
     
         7 . The method as claimed in  claim 6 , the method comprising selecting a value as a measure of a flow of the fuel from the plurality of first estimated flow values and from the plurality of second estimated flow values as a function of numerical values of the first estimated flow values from the plurality of first estimated flow values and numerical values of the second estimated flow values from the plurality of second estimated flow values. 
     
     
         8 . The method as claimed in  claim 2 , the method comprising:
 assigning the estimated type of fuel to a minimum air requirement; and   controlling at least one air actuator of the combustion device as a function of the assigned minimum air requirement.   
     
     
         9 . The method as claimed in  claim 2 , the method comprising:
 assigning the estimated type of fuel to a calorific value;   establishing a correction factor from the assigned calorific value and a set calorific value of the combustion device; and   correcting an air supply of the combustion device on the basis of at least one air actuator of the combustion device or on the basis of the at least one air actuator of the combustion device in proportion to the correction factor.   
     
     
         10 . The method as claimed in  claim 2 , the method comprising:
 correcting an operating characteristic curve on the basis of the estimated type of fuel, wherein the operating characteristic curve is selected from: a first operating characteristic curve between temperature-compensated heat output and fuel supply, or a second operating characteristic curve between temperature-compensated difference and fuel supply;   determining a current fuel supply and/or a current fuel gas supply on the basis of the corrected operating characteristic curve and on the basis of a further variable selected from: the temperature-compensated heat output, or the temperature-compensated difference; and controlling at least one fuel actuator of the combustion device as a function of the current fuel supply and/or the current fuel gas supply.   
     
     
         11 . The method as claimed in  claim 2 , the method comprising:
 assigning the estimated type of fuel to a calorific value;   correcting an operating characteristic curve on the basis of the assigned calorific value, wherein the operating characteristic curve is selected from: a first operating characteristic curve between temperature-compensated heat output and fuel supply, or a second operating characteristic curve between temperature-compensated difference and fuel supply;   determining a current fuel supply on the basis of the corrected operating characteristic curve and on the basis of a further variable selected from: the temperature-compensated heat output, or the temperature-compensated difference; and   controlling at least one fuel actuator of the combustion device as a function of the current fuel supply.   
     
     
         12 . The method as claimed in  claim 1 , wherein the combustion device comprises a closed- and/or open-loop control unit with an operator control unit and wherein a plurality of mapping rules for selectable fuels and dependent on the first temperature are saved in the closed- and/or open-loop control unit, the method comprising, on setting the combustion device, selecting the saved mapping rules, dependent on the first temperature and/or on the fuel composition, from the plurality of mapping rules with the assistance of the operator control unit. 
     
     
         13 . A combustion device comprising:
 a combustion chamber;   a fuel supply channel for supply of a fuel to the combustion chamber;   a mass flow sensor in or on the fuel supply channel; and   a closed- and/or open-loop control unit in communicative connection with the mass flow sensor;   wherein the mass flow sensor comprises a heating element, a first resistor element, and a second resistor element different from the first resistor element, and/or a third resistor element different from the first resistor element and/or a fourth resistor element different from the first and second resistor elements opposingly relative to the second resistor element, wherein the closed- and/or open-loop control unit is configured to:   record a first temperature signal indicating a first temperature of the fuel using a first resistor element of the mass flow sensor;   process the first temperature signal to yield a first temperature;   determine a compensable value by recording a heat output signal indicating a heat output of a heating element of the mass flow sensor;   process the heat output signal to yield a heat output;   determine the compensable value as heat output; and   estimate a flow value for the fuel supply by compensation of the value compensable as a function of the first temperature and/or as a function of the fuel composition and/or as a function of the fuel gas composition on the basis of at least one saved mapping rule dependent on the first temperature and/or on the fuel composition and/or on the fuel gas composition and on the basis of a calibration characteristic curve saved for a reference gas.