JP5449335B2 - Combustion facility control method using combination of resistance coefficient and flame front estimation - Google Patents

Description

  The present invention relates to a control method used in a combustion facility having a feeding device that feeds fuel to many moving grate, in which fuel is fed forward to continuously dry, ignite, burn, and burn out. Relates to a control method which is supplied from below the grate through a layer of fuel on the grate.

  In this type of combustion equipment, the speed of the feeder and possibly the moving grate are controlled based on the calculation of the resistance coefficient, for example on the basis of Bernoulli's principle, for the grate and the air flow and fuel passing therethrough. It is known to provide. A method of this kind is known from EP 955499.

European Patent No. 955499

  The object of the present invention is to provide a method of the kind related to the above, which allows a more precise control of the combustion. This method is achieved by a method of the type described above and, according to the invention, provides a correction of control based on the resistance coefficient using the estimated position of the flame front, provided by image analysis of the camera image of the combustion area. To do. In this apparatus, when it is detected that the position of the front surface of the flame is deviated from the optimum position, the set value or control signal of the resistance coefficient control apparatus can be corrected.

  In the following detailed description of the invention, the invention will be described in detail with reference to the embodiments of the inventive method shown in the following drawings.

1 schematically shows a configuration of a feed control device in which a set value of a resistance coefficient control device is additionally corrected (in the positive direction) by a flame front control signal. 1 schematically shows a configuration of a feed control device in which a set value of a resistance coefficient control device is measured by a flame front control signal. The flame front control signal directly shows the configuration of the feed control device that directly measures the set value of the feed control device.

  The control device shown in FIGS. 1 to 3 is a control device for each of the two parameters of the combustion facility, namely the speed 1 of the combustible fuel to the combustion chamber and the transport speed 2 on the continuous first combustion grate. It has. Each of the two controllers is shown as a PID controller, which is first controlled according to a grate velocity setpoint 3 based on the desired steam and energy production of the facility. Correction of the set value 3 of the grate velocity of the two control devices is performed by the resistance coefficient ζ on the combustion region. This resistance coefficient ζ is determined for the combustion region using, for example, the pressure on the opposite side of the combined combustion of the grate and the layer of combustible material thereon and the measurement of the flow rate, pressure and temperature of the combustion air. Calculated. The calculation of the resistance coefficient ζ is based on a variety of different equations. For example, there is the following formula.

ここで、Δρは火格子とその上の燃料上での圧力損失であり、ζは抵抗係数であり、ρは媒体（燃焼空気）の密度であり、νは媒体の速度であり、ｘは層流または乱流に依存する指数である。

Where Δρ is the pressure loss on the grate and the fuel above it, ζ is the resistance coefficient, ρ is the density of the medium (combustion air), ν is the speed of the medium, and x is the layer An index that depends on flow or turbulence.

ここで、ζ１は抵抗係数であり、Ｒは空気のガス定数（＝２８７．１ Ｊ／（ｋｇ Ｋ））であり、Ｔは空気の温度（Ｋ）であり、Ｐは空気の圧力（Ｐａ）であり、Δρは火格子とその上の燃料上での圧力損失であり、Ｖは空気の堆積流量（ｍ^３／ｓ）である。

Here, ζ1 is a resistance coefficient, R is a gas constant of air (= 287.1 J / (kg K)), T is an air temperature (K), and P is an air pressure (Pa). Δρ is the pressure loss on the grate and the fuel above it, and V is the air deposition flow rate (m ³ / s).

  Other formulas that give a resistance coefficient ζρν related to the thickness and density of the fuel on the grate may be employed.

  The resistance coefficient ζρν calculated in this way is necessary for the feed speeds 1 and 2 due to the fact that the resistance coefficient ζρν provides a good estimate of the thickness of the consumable layer in the combustion region. Gives excellent instructions for correction.

  According to the present invention, however, the resistance coefficient set value ζsp may be too high or too low and needs to be further corrected. This need for correction is solved according to the invention by the use of an estimated position Fpv of the flame front, which is solved by image analysis of the camera image of the combustion area. The camera is a red / green / blue (RGB) image camera in the preferred embodiment, but other cameras such as infrared cameras may be used.

  In the exemplary embodiment shown in FIG. 1, the flame front controller comprises a set value Fsp for the flame front and an estimated value Fpv for the flame front position, which is provided to the PID controller, The output from the PID controller for the flame front is to correct the control value and finally to correct the control of the transport speed 2 on the first combustion grate that is continuous with the speed 1 of the combustible fuel to the combustion chamber. Is added to the set value ζsp of the resistance coefficient control device.

  Similarly, FIG. 2 shows the corresponding device, where the output from the flame front control device is multiplied by the set value ζsp of the resistance coefficient control device.

  Further, FIG. 3 shows that the output signal from the flame front control device is multiplied by the set value 3 of the grate, and similarly, the output signal of the resistance coefficient control device is multiplied by the calculation result, and then to the combustion chamber. 2 shows an alternative configuration which is supplied to a PID control device for controlling a transport speed 2 on a first combustion grate continuous with a combustible fuel feed speed 1.

Claims (2)

Combustion equipment with a feeder that sends fuel to many moving grate, where the fuel is sent forward to cause continuous drying, ignition, combustion, and burnout, where the primary air for combustion is from below the grate A method for controlling the speed (1) of a feeder of a combustion facility adapted to be fed through a layer of fuel on a grate and the speed (2) of a first moving grate, the method comprising:
Calculating a resistance coefficient (ζρν) for the air flow and fuel through the combustion grate;
Controlling the speed (1) of the feeder of the combustion equipment and the speed (2) of the first moving grate based on the resistance coefficient (ζρν);
Providing a flame front position estimate (Fpv) by image analysis of the camera image of the combustion region;
Using the estimated position of the flame front to (Fpv), comprising the step of providing a correction control based on the resistance coefficient of the speed (2) of the speed (1) and the first moving grate feeder (Zetaronyu) ,
The method is characterized in that the correction of the control based on the resistance coefficient (ζρν) is made by introducing a feed forward of the estimated position (Fpv) of the flame front . Combustion equipment with a feeder that sends fuel to many moving grate, where the fuel is sent forward to cause continuous drying, ignition, combustion, and burnout, where the primary air for combustion is from below the grate A method for controlling the speed (1) of a feeder of a combustion facility adapted to be fed through a layer of fuel on a grate and the speed (2) of a first moving grate, the method comprising:
Calculating a resistance coefficient (ζρν) for the air flow and fuel through the combustion grate;
Controlling the speed (1) of the feeder of the combustion equipment and the speed (2) of the first moving grate based on the resistance coefficient (ζρν);
Providing a flame front position estimate (Fpv) by image analysis of the camera image of the combustion region;
Using the estimated position (Fpv) of the flame front to provide a control correction based on the resistance coefficient (ζρν) of the speed (1) of the feeder and the speed (2) of the first moving grate ,
The correction of the control based on the resistance coefficient (ζρν) is performed by introducing the estimated position (Fpv) of the flame front as a gain measurement factor, that is, by multiplying the set value (3) of the grate velocity. how to.

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