SU1765612A1 - Boilers capacity control method - Google Patents

Abstract

Use: automatic control system of boilers with a common steam manifold. Summary of the invention: with automatic control of the performance of a group of boilers by determining the upper and lower limits of performance, vacuum, fuel consumption of air and water of each boiler. using these limits as limiting parameters, measuring the pressure in the collector and regulating the supply of fuel to one of the boilers until one of the limiting parameters reaches one of the limits for varying the steam capacity of each boiler, determining the efficiency of each boiler as a function of steam capacity and slope of both branches these dependencies and the switching of the regulating effect to the other boiler, additionally determine the efficiency of the group of boilers, the deviations from the last efficiency of each boiler, neither the latter and the steam output of the respective boiler, the sum of certain relations with the steepness of the efficiency depending on the steam output of the respective boilers, depending on the amount received. 1 silt, (L S

Description

The invention relates to the field of automation of thermal processes and can be used on stations with a common steam collector.

The closest to the proposed technical essence is a method of automatic control of boilers with a common steam manifold by determining the upper and lower limits of the steam capacity, discharge, consumption of fuel, air and water of each boiler, using these limits as limiting parameters, measuring the vapor pressure in the collector and regulating the fuel supply in one of the boilers until one of the limiting parameters reaches one of the limits and then switching the regulating affecting another boiler, determining the dependence of the efficiency of each boiler on the steam capacity and the steepness of both branches of these dependencies, measuring the steam capacity of each boiler, comparing it with the optimum value and switching the regulating effect to another boiler depending on the slope of the dependencies of the boiler efficiency on the steam capacity, when changing the steam production in the direction of the optimum value, they regulate the flow of fuel to the boiler with greater steepness, and with a change in the steam output in the direction from the optimal value - to the boiler with the lowest steepness.

VJ ON SL

ABOUT

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The disadvantage of the method is the low accuracy of the control process due to the fact that when connecting the regulating effect on the boilers, the efficiency of the group of boilers is not taken into account, which determines the efficiency of operation of all the boilers, connected to the common controller, especially the variation in the steam output of boilers with the same steepness of the dependences of the efficiency of the boilers on the steam output, but different levels of the values of the efficiency to Each boiler.

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

The goal is achieved in that according to the method of automatic control of boilers with a common steam manifold by determining the upper and lower limits of performance, discharge, consumption of fuel, air and water of each boiler, using these limits as limiting parameters, measuring the pressure in the collector and regulating the fuel supply in one of the boilers until one of the limits is reached by any limiting parameter, measuring the steam capacity of each boiler, determining the dependence the efficiency of each boiler from the steam capacity and the steepness of both branches of these dependencies and the switching of the regulating effect to the other boiler, additionally determine the efficiency of the group of boilers, the deviations from the last efficiency of each boiler, the ratio of the latter to the steam capacity of the corresponding boiler depending on the efficiency of the steam output of the respective boilers, and switch regulating iruyuschee impact on another boiler, depending on the amount received.

The implementation of the inventive method is illustrated in the drawing, which shows a block diagram of an automatic control system for boilers with a common steam manifold.

The automatic control system of boilers with a common steam line contains boilers 1 operating on a common steam manifold 2, to which steam consumers 3 are connected, individual heat load regulators 4 that control fuel supply regulator 5, the signal is switched to the setters 6 in the desired sequence

the main controller 7. The signals 8 of fuel, air and water and the signals 9 of the steam capacity DI of each boiler are fed to an analog-discrete device 10, which

taking into account the state of priority block 11 by the sum of the steepness mi of the dependence of the efficiency rfi of each boiler on its steam production and the deviation of the boiler efficiency on the efficiency of the boiler group fj, related to the steam capacity of boiler 9, defined in block 12, switches the main signal regulator 7.

The dependences of the 13 efficiency on the steam capacity and the value of 14 optimum steam capacities of each boiler are set in advance from the outside according to the results of commissioning works.

The method is carried out as follows.

Signals of the main regulator 7 for increasing (decreasing) steam generating capacity

An analog-to-discrete device 10 is supplied, to which, in addition, signals 8 on technological limitations, signals 9 on the current steam output of each boiler are supplied. The analog-discrete device 10 selects a group of boilers whose technological parameters do not reach maximum (minimum) limits, compares the steam capacity of these boilers with their optimal steam capacity, and from the same group chooses boilers whose current steam capacity is less (more) than their optimum, and together with block 11 priorities for the sum of the steepness t, and the deviations of the efficiency of the boilers relative to the efficiency of all the boilers referred to the steam generating capacity

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i 1 J 1

 m .. (Pl + D2 + ... + D, Q

Hi b Pz-. + Dl u rft ..... + D n J i V. ./n - T

working on a common steam line (rj - j /) / Dj, selects the boiler with the highest priority on the left (right), to the motor setting unit 6 of which connects the signal of the main regulator 7, and, with the same slope, the dependences of the efficiency factors of the boilers on

steam generating capacity and different levels of efficiency values of each boiler analog-discrete device 10 together with the unit

11 priorities chooses the boiler with the highest priority on the left (right) according to the relative deviation of the efficiency of the boiler from the efficiency of the group of boilers

(y, - rj) / D, on whose motor setting device 6 connects the signal of the main regulator 7, which increases the efficiency of the group of boilers by 0.5-1.5%.

In the absence of boilers whose steam output is less (more) than optimal. Analog-discrete device 10 together with priority block 11 connects the signal of the main regulator 7 to the motor setting device 6, which changes the setting of the individual heat load regulator 4 that changes fuel supply to the selected boiler 1 through the regulatory authority 5.

The priority in terms of the sum of the steepness and the deviations of the boilers 'efficiency from the boilers' efficiency of each boiler, related to the steam generating capacity, are generated in a block

Claims (1)

12 on the basis of signals 9 on the current steam capacity of boilers and the dependence of 13 efficiency on the steam capacity of each boiler according to the results of thermal tests of boilers during commissioning tests, the invention The method of automatic control of boilers with a common steam manifold by determining the upper and lower performance limits, vacuum, the cost of fuel, air and water of each boiler, using these limits as limiting parameters, measuring lagging in the collector and regulating the supply of fuel to one of the boilers until any limiting parameter reaches one of the limits, measuring the performance of each boiler, determining the dependence of the efficiency of each boiler on the steam capacity and the steepness of both branches of this dependence, and switching the regulating effect to the other boiler that, in order to increase accuracy, the efficiency of the group of boilers is additionally determined, the deviations from the last efficiency of each boiler, the ratio of the latter to the steam capacity the corresponding boiler, the sum of a certain relationship with the steepness of the efficiency depending on the steam output of the respective boilers, and the regulating effect is switched to another boiler depending on the amount received.