SU1305493A1 - Method for controlling medium discharge from firing device built in straight-through boiler circuit - Google Patents

Abstract

The invention relates to a power system and allows for improved control accuracy. The actual value of the pressure drop (PD) on the throttle washer 18 installed in the steam line of the separator (C) 2 is measured. The predetermined value of the PD on the washer 18 is determined from the previously determined steam flow rate on the steam line C 12. L

Description

favor ratio of actual and given values of PD. The controller 4 generates an effect on the opening or closing of the valve 3, depending on the value of the power supply, which, in turn, causes an increase or decrease in steam leakage to the discharge line 1. The invention relates to the field of heat energy and can be used to regulate the starting conditions of a flow boiler.

The aim of the invention is to control accuracy.

The drawing shows the scheme of the method implementation /

On line 1 of the medium discharge from the pilot separator 2, a valve 3 is installed, controlled by regulator 4, Differential pressure sensors 5 at the throttle washer and medium temperature 6 before the separator are connected to the first and second inputs of the adder 7, the output of which is connected to the first input block 8 division. The pressure sensor 9 in the separator is connected to the inputs of nonlinear converters 10 and 11. The output of non-linear converter 11 is connected to the third inverting input of the adder 7, and the converter 10 to the second input of the dividing unit 8, the output of which is connected to the first inputs of the adder 12 and block 13 multiplying, a master is connected to the second inverting input of the summer, and 12 to the second input of the block 13. 14 relative non-L1-1CHINES of steam hopping to reset line 1. The output of block 13 is connected to the third input of the adder 12, the output of which is connected to the input of the quadrant 15 whose output is connected to the first input of block 16 of division. The second input of the latter is connected to the pressure sensor 9 in the separator, and the output is connected to the second input of the dividing unit 17, To the first input of the dividing unit 17, rO connected

differential sensor 18 on the throttle washer in the steam line after the separator. The output of block 17 is connected to the input of controller 4.

The booster 4 stops the effect on the valve 3 when, at a certain block 8, the dryness of the medium in C 12, the relative amount of steam leakage into line 1 corresponds to the signal of the setting device 14. silt

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 During the start-up of the boiler, the pressure upstream of the separator is kept constant by affecting the valve installed at the inlet of the medium to the separator, and the flow rate of the medium is stabilized by the boiler power regulator. At the beginning of start-up, the medium discharge valve 3 is fully open, and the valve installed in the steam line after the separator is completely closed. At the same time, the effect on heat generation in the furnace at a given speed increases the temperature of the medium in the evaporation tract. After increasing the enthalpy of the medium in front of the separator to the value at which the separation of the steam-water mixture begins, the pressure in the separator begins to grow. When the pressure in the separator rises to a predetermined value, the valve starts to open; Lenny in the steam line after the separator. Steam consumption increases the impact on the valve in the steam line so as to: provide a given heating rate of the superheater. After the steam valve is fully opened, the regulator 4 is discharged from the pilot separator. In this case, as in the known method, the sum of the signals from sensors 5 and 6 characterizes the enthalpy of the medium in front of the separator, the nonlinear converter 11 in accordance with the signal level of the sensor 9 of the pressure in the separator generates a signal proportional to the enthalpy of water in the separator, and the output signal of the adder 7 is proportional to the difference enthalpy medium in front of the separator and water in the separator.

Nonlinear converter 10 generates a signal proportional to the heat of conversion, and dividing block 8 signals the dryness of the medium in the separator. Unit 14 determines the relative value of the specified steam breakthrough to the discharge line 1 in parts of the mass flow rate of the medium in the discharge line. The difference between the signals of the setting device 14 and the multiplier 13 when the dryness of the medium in the separator increases from 0 to 100% linearly decreases from the maximum value to 0, i.e. according to the same dependence as the flow rate, the effect on the discharge valve 3 in the discharge line, measured in before — when at a certain block

decreases. At the moment when the signal of the block 16 becomes larger than the signal of the sensor measuring the difference on the throttle washer 18, the controller 4 begins to act on the valve cover 3, which causes a decrease in the steam supply to the discharge line 1 and a corresponding increase in steam consumption in the steam lines. The controller 4 stopped x from the flow of the medium into the separator. At the same time, this difference is proportional to the signal of the setting device 14 and, therefore, characterizes the amount of steam leakage at the discharge also in terms of the flow rate of the medium into the separator. Thus, the block 13 forms an amendment, the subtraction of which from the signal of the setting device 14 converts the specified value of the relative leakage of steam at the discharge into the value measured in dale from the flow rate of the medium to the separator. The adder 12 determines the specified value of steam consumption in the steam line as an algebraic sum of signals from dividing unit 8, multiplication unit 13 and setting unit 14. Quad 15 and dividing unit 16 convert the signal of a given steam consumption to a signal of a given difference in throttle washer 18 in the steam line . In this case, the quad 15 implements a quadratic dependence of the differential on the steam consumption, and the block 16 of the division takes into account the influence of the vapor pressure on the differential value. The dividing block 17 determines the ratio of the actual value of the pressure drop on the throttle washer 18 to the predetermined value of this difference, forming a decrease in its signal that the dividing unit 16 dividing it, and the regulator 4 by acting on the relief valve 3 maintains a constant signal value of the block 17 division. If at the moment the regulator 4 is turned on, the pressure drop on the washer 18 will be greater than that set by block 16, regulator 4 will affect the opening of valve 3, but since it registers the effect of regulating valve 3 closure. When set, setting unit 4 increases with 45 in the separator to 100% pa 3 to the complete closure of a constant gap throughput 1 reset in accordance with

Pan 3 at this moment is fully open, 50 signal setpoint 14.

the effect of controller 4 is blocked by valve limit switch 3.

As the dryness of the medium in the separator increases, the signal of dividing unit 8 increases and, accordingly, the signals of adder 12, quad 15 and dividing unit 16 increase. The signal unit 17 division

There is no impact on the reset valve 3 when, at a certain block

decreases. At the moment when the signal of the block 16 becomes larger than the signal of the sensor measuring the difference on the throttle washer 18, the controller 4 begins to act on the cover of the valve 3, which causes a decrease in steam leakage to the reset line 1 and a corresponding increase in the steam flow rate in the steam line. The regulator 4 stops the medium dryness in the separator and the relative amount of steam leaks into the reset line 1 .. corresponds to the signal of the setting device 14, which is controlled by the equality of the actual value of the differential on the throttle washer to the specified differential formed by the adder 12, the multiplication unit 13, the quad 15 and the division unit 16.

If it is necessary to increase the steam leakage to the reset line 1, the signal of the setting device 14 is increased, the signals at the output of the adder 12, at the output of the quad 15 and at the output of the dividing unit 16 are reduced, which leads to an increase in the signal at the output of the dividing unit 17. In this case, the regulator 4 acts on the relief valve 3 in the direction of opening until an increase in steam leakage into line 1 and a corresponding decrease in steam flow in the steam line cause a decrease in pressure drop on throttle washer 18 to the level specified by the reduced signal of block 16. If it is necessary to reduce steam leakage into the discharge line 1, the setter 14 acts to inhibit the effect of the regulator 4 on the cover of the valve 3. With the set position of the setter 14, the regulator 4 as the medium increases in dryness Arathor to 100% covers the valve 3 to complete closure, thus providing a relatively constant value in the slip line pair 1 in accordance with the reset value

The use of the differential pressure on the throttle washer in the steam line to control the operation of the separator provides a higher accuracy of control of the discharge of the medium.

Claims (1)

Invention Formula The method of controlling the discharge of the medium from the in-line flow cable 513054936 boiler kindling separator by that, in order to ensure accuracy measuring signals by adjusting temperature, measuring the actual the medium in front of the built-in valve, the ne-value of the pressure drop across the pressure drop at the throttle ball washer installed in the steam generator installed in front of the separator is 5 °. separator lines, and, by definition, “and according to the previously measured steam flow rate in the steam the dryness of the medium in the separator, the separator lines determine the specified setting the steam leakage value and the 6p-value of the pressure drop across the drosedelek by these values given by the assigned washer installed in the steam vapor flow in the steam line of the separator separator line, and Pa and subsequent changes in the position of the command signal use from the back of the valve reset command for actual and specified values a signal that has a differential pressure.