SU1588995A1 - Method and apparatus for automatic control of combustion of pulverulent coal fuel - Google Patents

Abstract

The invention relates to automatic control of combustion in furnaces, predominantly energy generators, using coal as a fuel with a low yield of volatile substances and low calorie content, and allows increasing the technical resource of the furnace and the reliability of slag discharge. This is achieved by varying the consumption of pulverized coal by the temperature of the walls of the furnace by a command signal and the redistribution of fuel oil in the additional bottom nozzles. The flow rate of the G N nozzles is determined by the formulas G N = 0.23G m (C ± S) [1- * 98N (C ± S)] / (1 + R), N = 1.2

G N = 0.23G m (C ± S) * 98N (C ± S) / (1 + R), N = 3.4, where the plus sign for nozzles is N = 1.3

R = (3-4) √ Σ V I

C = 2V 1-V 2-V 3

S = √3 (V 2-V 3)

G m - the total consumption of fuel oil, t / h

I = 1 R-degree flare offset

C, S are the cosine and sine guides of the plume displacement in furnaces relative to thermocouples with a reduced temperature V I

I = 1,2,3. In the device, thermocouples 2,3 and 4 and nozzles 17, 18, 19 and 20 are placed in the wall of the furnace evenly on the respective circles centered on the axis of the furnace 1. Signals are recalculated in the microprocessor 6. In the D / A converter 7 and logic elements 13 and 14 are formed the commands controlling the control valve 10 and the spools 12, 15 and 16 connected to the injectors 17, 18, 19 and 20. 2 sec. f-ly, 1 ill.

Description

35

The invention relates to the automatic control of burning in the top, - oh, mainly steam generators, using pulverized fuel with a scarlet yield of volatile substances and a calorie content.

The purpose of the invention is to increase the technical resource of the furnace unit and increase the reliability of the discharge of the donkey.

The drawing shows an electrohydraulic functional arrangement of the device for automatic control of the combustion of pulverized coal.

The device for automatic regulation of the burning of pulverized coal consists of thermocouples 2, 3 and A mounted on the walls of the furnace 1, connected to the decision block, containing its analog-to-digital converter 5 connected to a microprocessor 6, connected to a digital-analogue converter. Telem 7, to the control inputs of which timer 8 is connected and the output of which is connected via proportional integral link 9 to control valve 45, 10 through relation detector 11 with electric actuator of spool 12 of fuel oil divider, and through logs Elements 13, 14 are with electric drives 15, 16 of two-position spools connected to pairs of opposite nozzles 17, 18 and 20, 19. Flare angle oi is measured from the first thermocouple 2 in the direction of increasing the numbering of the thermocouples (as well as the nozzles). The angle between the first thermocouple and the nozzle is 45 °. The power supply units and electric control valve and spools are not shown in the drawing

 55

five

0 5

about

45

five

The method is as follows. The temperature of the walls of the furnace is measured by three thermocouples 2 placed on a horizontal circle with a center in the middle of the furnace, relative to the temperature Tr of the external medium.

The coordinates of the torch deviation from the vertical axis of the furnace are calculated — the degree of the torch displacement (g) and the direction of J o (the cosine of C) and the sine of the angle

displacement according to the formulas:

I g J „

 - l2l / - ;; C 2V -V2-Vj; S (

where v; (T - T) reduced the temperature of the walls of the furnace (relative to the external environment;

T, T are, respectively, the temperature of the walls of the furnace at the points (i 1,2,3) of measurement and the average temperature relative to the external environment; K 3 - 4 - coefficient taking into account the effect of the screen and lining on the wall temperature.

Calculate the consumption of additional nozzles Sf by the known total consumption of fuel oil Sdd and the position of four additional nozzles installed in the furnace walls evenly on a circle centered on its vertical axis in a form that minimizes consumption C (p Od, -C / 3 (1 + g).

 An estimated amount of fuel oil is diverted to the additional nozzles by means of a control valve installed on the common fuel oil line.

The allocated fuel oil flow rate G for additional nozzles is redistributed to the corresponding nozzles, and the individual valves are controlled to the governor according to the equations:

g, 0.71 Gcp (1 + S / C) (1-I2 (C + S)); g 0.71 Gcp 1 + S / C) - l (C + 5)

for the first pair of opposing nozzles,

g2 0.71 Gcp (1-S / C) (1-g (C-S)); g. 0.71 Cm (1-S / C). )

tI

for the second cross lay of a pair of nozzles,

where I (C + S) is a single step function.

The device for automatic control of the combustion of a pulverized fire works as follows.

When the torch deviates from its position on the vertical axis of the furnace 1 in three thermocouples 2, 3 and 4, mutually unequal thermoel, proportional to the wall temperatures, generates the propulsive forces supplied to the digital-to-analog converter 5 of the decision block. Microprocessor 6 according to the programmed in it Adequate to the equations in the claims, calculates the coordinates of the plume - the degree of displacement r and the directional cosine C and the sine S of the displacement angle relative to the direction of the first thermocouple 2.

At the same time, the microprocessor 6, by a signal about the total consumption of fuel oil in the furnace G, also arrives at the analog-digital converter e, and the calculated coordinates of the flame determines

integrating element 9 consisting of. integrators and adder, to the electric drive of the control valve 10, which, by this command, sets the required total fuel oil consumption for additional nozzles 17-20.

At the same time, the sum and difference of the cosine and sine ci

10 torch displacements arrive at a relationship detector 11, where an electrical command signal is converted, proportional to the flow ratio (g "+ g3) and (g 2. B 4.) opposite junction pair J5 knob, controlling the electric actuator of the spool 12 by the fuel oil divider, and logic elements And, the controllers of electric drives 15 and 16 of two-position golders.

20 At the same time, the spool 12 of the fuel oil divider 12 connected to the detector 11 redistributes the flow rate G between the nozzle pairs in relation to

25

g (

g3

g

84C + S

C - S

a two-position spools alternately, at a signal from the logical elements And, include one of the opposite

30 nozzles 17, 18 and 19, 20, shifting the flare of the axis of the furnace. In this way, the stabilized flame in the center of the firebox provides a more favorable scaling conditions, which, in its turn, allows lowering the temperature of the hearth, while maintaining reliable liquid slag removal with a minimum removal of fuel oil from the main supply line of the main fuel oil nozzles.

Claims (2)

1. A method for automatically controlling the burning of coal coal by changing the consumption of fuel oil in minimized fuel oil consumption at the end of the total fuel oil line, consumption of additional nozzles 17-20. The calculation of torch coordinates and the amount of fuel oil consumption is made periodically upon a command from timer 8. After the calculation results are completed, they are in the form of analog G Secondly, according to the command signal, determined by the measured temperature, the degree of the firebox and the supply of fuel oil to the additional nozzles, about 50L and h with the fact that, in order to increase the reliability of slag discharge and increase the technical resource of the furnace, simultaneously measure the temperature of the  .,. . Firebox at three points, evenly emits them into an electrical analog signal- "Placed around a circle having , "", "" "G, og, o center on the vertical axis of the firebox, crushing, retaining its value to barely , - oh gig n, the torch coordinates are read by the formatting command from the timer o. signal G (B comes from digital-analog pre-lam., Former 7 through proportional-g; . Phases and sums and differences of the cosine (C) and sine (S) guides of the bias angle oi are fed to a digital-to-analog converter 7, which converts the integrating link 9 consisting of. integrators and adder, to the electric drive of the control valve 10, which, by this command, sets the required total fuel oil consumption for additional nozzles 17-20. At the same time, the sum and difference of the cosine and sine ci the torch displacements arrive at a relationship detector 11, where an electrical command signal is transformed, proportional to the flow ratio (g + + g3) and (g 2. 4. 4.) pairs of opposite nozzles, controlling the electric drive of the spool 12 of the fuel oil divider, and the logic elements AND, control electric drives 15 and 16 two-position golders. At the same time, the spool 12 of the fuel oil divider 12 connected to the relationship detector 11 redistributes the flow rate G between the nozzle pairs with respect to g ( g3 g 84C + S C - S a two-position spools alternately, at a signal from the logical elements And, include one of the opposite 30 nozzles 17, 18 and 19, 20, shifting the flare of the axis of the furnace. In this way, the stabilized flame in the center of the firebox provides a more favorable scaling conditions, which, in its turn, allows lowering the temperature of the hearth, while maintaining reliable liquid slag removal with a minimum removal of fuel oil from the main supply line of the main fuel oil nozzles. 4p Formula of the invention 1. A method for automatically controlling the burning of coal coal by changing the consumption of fuel oil in 2V, V 3 s -J (V2- vO, de  g: uh g is the degree of flame displacement from the axis of the furnace, s; K 3 - 4 is the coefficient taking into account the influence of the screen and Q Q obur holes on the wall temperature; i 1,2,3 - numbers of measurement points; re (, 4)),   given rate, 5 and fuel oil consumption in additional odds 8995 .8 (1 + S / C) 1- (CtS); , 71Gcp (1tS / C) (C + S), where en additional nozzle; . i7 (C + S) is a single step function (plus sign refers to the first pair of opposite nozzles (, 3), minus sign h To another para- re (, 4)), additional 20 heat sink walls of the furnace relative to the external environment; T- is the temperature of the walls of the furnace at the measurement points; T is the ambient temperature; S is the cosine and sine guides of the flame displacement angle 25 relative to the first point, at which the temperature of the firebox wall 30 is measured, and received; for the origin, according to the calculated torch coordinates, the known total fuel oil consumption and the known position of the additional fuel oil nozzles, placed Hbix on the furnace walls evenly around the circumference, which has a center on the furnace axis, calculate the total fuel oil consumption in the additional burners by the ratio 35 40 & f (1 + g). where Sf - the total consumption of fuel oil in the additional burner;  The consumption of fuel oil, the removal of fuel oil into additional burners and distribute it to additional burners according to the ratios m: 0 50 five 0 five dunks are used as a command signal to control the consumption of fuel oil, 2. A device for automatic regulation of the capped coal fuel containing temperature sensors of the walls of the furnace, made in the form of thermocouples connected to the decision block, logic elements AND, flow control valve installed in the common line, characterized in that, in order to increase the reliability of slag discharge and technical resource of the furnace, which has four additional nozzles, it additionally contains a sensor for the total consumption of fuel oil, a proportional-integrating element, a ratio detector, a spool separator, two The position spools and timer, the thermocouples and additional nozzles are evenly placed around the circumference, having the center on the vertical axis of the furnace, the fuel oil flow sensor and the timer are connected to the decision block, which is connected via a proportional-integrating element to the control valve, and the relationship detector to the spool fuel oil divider ,, and through logical elements I - with double-position spools connected to the chains of the opposite additional nozzles.