SU1765626A1 - Boiler burner fuel supply automatic regulator - Google Patents

Description

one

(21) 4772635/06

(22) 12.22.89

(46) 09/30/92. Bul Number 36

(71) State Research Institute of Power Engineering. G.M. Krzhizhanovskogo

(72) M.I. Saparov, V.V.Ermakov, S.A. Fadeev, I.A.Strelchenko, A.V.Bugasov

(56) USSR Author's Certificate No. 1702109, cl. F 23 N 1/08, 1988. (54) A DEVICE FOR AUTOMATIC REGULATION OF FEEDING A COMBUSTIBLE MIXTURE IN THE BURNER OF THE BOILER

(57) The invention relates to a power system and makes it possible to increase the control accuracy by introducing the sensor 6 of the position of the regulator 5, which determines the activation of the key 7 in a fixed period of time. This eliminates the occurrence of an error in the hysteresis of the flow characteristic, since the measurement of the air flow is made only with an increase (or decrease) in the flow rate of the latter in the additional pipeline 1. 1 sludge.

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The invention relates to a power system and can be used in automatic control systems of a boiler.

The aim of the invention is to improve the accuracy of regulation.

The drawing shows a diagram of the device.

The device contains an additional pipeline 1 in the chute 2 of the hopper 3, an air flow sensor 4 in the additional pipeline in which the regulator 5 is installed with a position sensor 6, an electronic switch 7, a quad 8, two multipliers 9, 10, a memory element 11, a divider 12 , the square-root calculation element 13, a parametric generator 14, an input connected to a coal dust density sensor 15, two threshold elements 16, 17, and outputs connected to a regulator servomotor 18.

The operation of the device is as follows.

The outflow of the coal dust fluidized in the bunker through the chute 2 is accompanied by the entry of coal dust into the open end of the output end of the additional 1 pipeline. Moreover, the level of the aforementioned intake depends on the amount of air flow through the pipeline, which is regulated by the servomotor 5. The entry of coal dust particles into the additional pipeline 1 is determined by their speed of movement and weight, balanced by the velocity air pressure in the pipeline with the servo motor 5. The regulating member of the servomotor 5 sets air flow in the additional piping 1. The minimum air flow rate is chosen from the condition of exclusion of coal dust at its maximum flow area in the measurement sensor 4, a maximum value of the air flow conditions are selected from eliminating coal dust emission from the additional conduit 1 at its minimum flow rate. According to experimental data, the calibration characteristics obtained with a decrease and an increase in the consumption of coal dust have a different character, in one case the shape is concave, in the other case it is convex. The maximum measurement error due to the hysteresis of these characteristics reaches ± 4%.

To eliminate this error, the air flow in the additional pipe 1, measured by sensor 4, is measured only at the moment when it exceeds its value over the coal dust consumption. This moment is formed by the regulatory body.

servomotor 5, which can be performed, for example, in the form of a Cam mechanism, overlapping the effective cross-section of the pipeline 1 according to the sawtooth law.

The position sensor 6 is triggered in this case at the maximum flow rate (upper saw point), which determines the activation of the switch 7, which passes the output signal from the flow sensor 4.

From the condition of equality of speed (dynamic) air pressure in the additional pipeline 1 and coal dust

15

Tvo v vo py v 22

should ratio:

vy

VI

WHO

BUT

where Vy and VB03 - respectively, the speed of coal dust and air;

/ OuI / Eoos - according to density

coal dust and air.

From the expression obtained, it follows that the velocity of the coal dust in the additional pipeline depends on the air flow rate and the density of the coal dust, which are measured by sensors 4, 15. The output signal from sensor 4 (for example, a rotameter with electrical signal output) after conversion in quadrant 8 and multiplier 9 is divided in divider 12 by an output from generator 14 proportional to the density of the coal dust. After conversion, the output of element 13 receives a signal corresponding to the value of the velocity Vy of the coal dust, which, after multiplying by

the multiplier 10 is converted to a mass flow rate by the density value of the latter. This parameter is regulating for the threshold elements 16, 17, which are set to the maximum and minimum values of the required consumption of coal dust in the drain 2.

Thus, the device regulates the consumption of coal dust by a parameter corresponding to its

the absolute value, at measurements of which the influence of the flow characteristic hysteresis is excluded.

Claims (1)

Apparatus of the Invention A device for automatically controlling the supply of a combustible mixture to a boiler burner having a coal dust bin with a drain, containing a fuel flow sensor in a drain, a regulating device connected to the regulator servomotor, a second regulator, an additional pipeline connecting the air supply pipe to the flow sensor, the end of the additional pipeline, located in estrus, is directed vertically upwards, and the regulating device is designed as a parametric generator Two threshold elements connected to the servomotor of the regulator, characterized in that, in order to increase the control accuracy, it additionally contains sensors for the density of coal dust and the position of the servomotor of the regulator in the additional pipeline, and the air flow sensor in the additional pipeline , an electronic key with control and signal inputs, a quad, two multipliers, a divider, memory elements and square root calculations, with the parametric input the generator is connected to the coal dust density sensor, and the output is connected to the first inputs of the first multiplier and divider, the output of which is connected through the square root calculating element to the second input of the first multiplier, the output of the threshold elements connected to the inputs, the output of the position sensor is connected to the control input of the electronic key, the signal input of which is connected to the output of the air flow sensor, and the output through a quad with the first input of the second multiplier, the second input connected to the output of the memory element and second input divider.