SU1216568A1 - System of boiler automatic control with mills operating for groups of burners - Google Patents

Description

one.

The invention relates to the automatic regulation of the combustion processes of high-power multi-stream direct boilers, mainly with a furnace according to the direct injection scheme, divided into semi-furnaces.

The aim of the invention is to improve the accuracy of controlling the position of the flame in the boiler furnace.

FIG. a block diagram of the automatic control system is depicted; in fig. 2 is a block diagram of the connection of the primary air flow sensors.

The system contains regulators 1 of the secondary air flow connected to the actuators 2 with sensors 3 of the regulator 4 (regulating gates of the secondary air flow for a group of burners from one mill on the secondary air path 5 to the counter burners 6 and 7 of the lower rus and burners 8 and the upper rusa of the respective semi-furnaces The system is equipped with sensors 10 and 11 of the heat transmission of the water-vapor path, which are located in the corresponding semi-furnaces, for example, with steam temperature sensors in the middle of the water and steam tract, successively connected adders 12 and 13, nonlinear elements 14 and 15, integrators 16 and 17, control switching units 18 and 19, and output breeders 20 and 21. In addition, the system is equipped with corrective setting units 22 and 23 and sensors 24 - 27 primary air flow rate in half-mill mills, with sensors

24 characterize the flow of primary air in the mills operating on the burner 6 lower rus, sensors

25 is the primary air flow rate in mills operating on the counter burner 7 of the lower rus, sensors

26- on the burners 8 of the upper Russ, and sensors 27 on the counter burners 9 of the upper Russ of their half-shoes, respectively. In this case, the sensor 24 is connected to the controller 1, which changes the flow rate of the secondary air: ha

on the counter burners 7 of the lower rus, and the sensor 25 on the regulator 1, which changes the secondary air flow to the counter burners 6 of the same russ (Fig. 2). The sensors are connected in the same way 26

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and 27 to the regulators 1, which change the flow rate of secondary air to the counter burners B and 9 upper wheels. The sensor 10 of the heat sen sition is connected to the adder 12 with a sign, and to the adder 13 with the sign -, respectively, the sensor 1 of the heat prospect is connected to the adder 13 with the + sign, and to the adder 12 with

By means of the sign Correcting setting device 22 is connected by means of the control switching unit 18 and the breeder 20 to the regulators I of the secondary air flow rate of one semi-furnace

the boiler (semi-furnace A), and the adjusting unit 23 through the control switching unit 19 and the heater 21 to the regulators 1 of the other semi-furnace (semi-furnace B). The outputs of breeders 20 and 21 are connected to separate inputs of regulators operating on a group of burners of one semi-furnace.

The system works as follows.

Regulators 1 maintain a predetermined ratio of expenditures in the main (according to the position of the regulator) and the primary air supplied to

Since the flow of primary air into the mill characterizes the flow of the fuel-air mixture into the furnace of the boiler at its constant loading, the regulators 1 act as regulators of the fuel-air ratio in the counter-air flows. At the same time, the position of the torch is stabilized by the aerodynamic forces of the oppositely intersecting jets. If at the same time the number of mills operating in semi-furnaces turns out to be asymmetrical (or their performance is significantly different for different reasons), then heat spherical distortions along the water-steam paths occur. For example, in the semi-furnace A there are four mills, and in the semi-furnace B - three (or two). In this case, as a result of

when the heat skew is skewed, adders 12 and 13 receive signals from sensors IO and 11. Moreover, at adder I2, the signal increment will be positive (with a + sign), and at the accumulator 55 mate 13 - equal in magnitude to a negative (with a sign). When the deviation of heat overshoot is tolerated, the signals at the outputs of adders 12 and 13 exceed the permissible limits specified by nonlinear elements 14 and 15, and at the outputs of integrators 16 and 17, correction signals appear such that controllers 1 (heatsink A) increase the flow rate of secondary air to the burners of the semi-furnace A and, accordingly, reduce the flow of secondary and burned air to the burners of the semi-furnace B. The signals to the regulators 1 are fed through breeders 20 and 21 connected to the integrators through the switching blocks 18 and 19 laziness, which allow connecting regulators 1 and 22 to adjusting regulators 1. Simultaneously with the general correction of secondary air flow in the semifilters in accordance with the heat absorption of water-vapor flows, the regulators 1, which change the secondary air flow to the counter burners one Rusa, for example, on groups of burners 6 and 7, redistribute the secondary air flow inside the semi-furnace between counter burners of the same Rus according to signals from sensors 24 and 25, 26 and 27 according to the flow rate of the primary fuel hydrochloric mix on opposing burners. For example, when from

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The key mill for a group of burners 6 (FIG. 2), the regulator 4 on the path to the burners 6 changes its position according to the performance (in this scheme, the primary air flow) of the mill per group of burners 7, and the other body 4 on the counter burners 7 covers up to the position determined by the minimum flow of secondary air through the inactive burners, thus restoring the position of the torch in the boiler furnace by using aerodynamic forces of opposing t5 jets. Since the secondary air flow rate changes in accordance with the primary fuel-air mixture flow rate, along with the stabilization of aerodynamic processes, this leads to an improvement in the quality of the combustion process as a whole. As a result, flushing of heating surfaces and heat distortions along the water-vapor paths, hydraulic distortions and limitations on boiler performance with an asymmetrical number of dust systems operating in semitrails are eliminated, and the speed and accuracy of adjustment are 30%.

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Claims (1)

AUTOMATIC CONTROL SYSTEM OF THE BOILER WITH MILLS OPERATING FOR BURNER GROUPS, comprising heat sensing sensors of the steam and steam flow paths connected via adders and non-linear elements with integrators, output multipliers and primary air flow sensors, which differs in that, in order to increase the accuracy of regulation it is equipped with corrective adjusters, control switching units 1 and by the number of mills secondary air regulators with actuators, sensors positions and regulatory bodies, and the correcting adjusters are connected to control switching units connected between integrators and multipliers, the outputs of the latter are connected to the first inputs of the secondary air regulators, with the second inputs are the outputs of the position sensors, with the third - primary air flow sensors in the mill, operating on counter group of burners.