SU1455144A1 - Method of automatic regulation of drying capacity of pulverized coal direct injection system - Google Patents

Abstract

The invention relates to the automation of dust preparation plants for boiler units of thermal power plants and allows for greater control accuracy with restrictions on drying of the fuel by maintaining the maximum allowable temperature of the drying agent in the gas intake shaft. When restrictions arise on the drying of fuel, the temperature of the aerosime mill decreases and the temperature controller 4 of the drying agent connects the actuator t1 of the dm gas additive gate to its output and maintains the temperature of the gas agent in the gas intake shaft as permissible, and the output of the air mixture regulator 1 disconnected from actuator 1t during this period. With a further decrease in the air mixture temperature to the minimum value, the converter t4 operates and switches the switch 12 to the position in which the output of the regulator 1 is connected to the actuator 13 of the fuel supply device, and the output of the regulator 7 of the mill loading, thereby maintaining the temperature of the air mixture by changing fuel consumption. Keeping the temperature of the drying agent at the maximum permissible level, and the temperature of the air mixture behind the mill at the minimum permissible level, allows to improve the accuracy of controlling the drying performance of the dust system. 1 il. (

Description

The invention relates to automatic dust preparation installations of Boiler units of thermal power plants.

The purpose of the invention is to improve the control accuracy of the drying efficiency with limitations on

drying the fuel.

 The drawing shows the structure of an automatic system implementing the proposed method of automatic control.

The system contains a regulator 1 of the air mixture temperature, to the inputs of which the sensor 2 and unit 3 are connected. the mills, to the input of which the signal from the sensor of the mill loading 8 and the setting signal 9 are supplied. The output circuits of the regulators 1 and 4 are connected via the switching contacts of the remote switch 10 to the actuator 11 and flue gas additives, and the output circuits of regulators 1 and 7; through the switching contacts of the remote switch 12 to the executive mechanism 13, which controls the performance of the fuel supply unit. The control inputs of the remote switch 10 are co-; Dineny with outputs More regulators 1 and 4, and the control inputs of switch 12 - with an output Less regulator 7 and with the output of the analog relay converter 14, the input of which is connected to the sensor 2 of the mixture of the air mixture behind the mill.

A method for automatically controlling the drying capacity of the dust system is carried out as follows.

In normal operation of the pype-system, when there is a supply of drying capacity and the temperature of the drying agent below the maximum permissible value, controller 1 maintains the optimum drying temperature value of the air mixture at the mill by influencing the actuator 11 of the flue gas additive to the flue gases (control output torus 1 is connected to the executive mechanism 11). Regulator 7 under

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keys to the actuator 13 and maintains the required performance of the psysystem. The controller 4 is disconnected from the actuator 11 and operates on Less. When restrictions on the drying of the fuel occur, for example, due to an increase in the fuel supply or its initial humidity, the regulator 1, try to keep the set value of the air mixture temperature, reduces the addition of dm gases, which leads to an increase in the temperature of the drying agent. When the temperature of the drying agent increases to the maximum allowable value, the controller 4 triggers more and connects the actuator 11 to the output of the controller 4, which maintains the maximum allowable temperature value of the drying agent. The output of controller 1 during this period is disconnected from the actuators.

With a further decrease in the air mixture temperature to the minimum permissible value according to the conditions of fuel drying, the analog relay relays 14 and switches the remote switch 12 to a position in which the output of the regulator 1 is connected to the actuator 13 of the fuel supply device, and the output of the regulator 7 is disconnected. At the same time, the switch 12 changes the parameters of the dynamic setting and reduces the reference signal to the controller 1, ensuring the required quality of regulation in the mode of maintaining the minimum value of the air mixture temperature by affecting the change in fuel supply.

In this way, the performance of the dust system is maximized while ensuring the required degree of fuel drying. An increase in the load of the boiler in such a mode is achieved by increasing the productivity of other dust systems that have not yet reached the limitation on spar.

When the drying capacity is increased and the temperature of the air mixture is increased, the remote switch 12 (by the signal from the output of Less regulator 7) and switch 10 (by the signal from the output of More of regulator 1) are switched in reverse order.

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Claims (1)

Formula invented A method for automatically controlling the drying capacity of a direct dust injection dust system with a fuel supply device, a gas intake shaft and a pgber at gas drying of fuel by measuring the temperature of the slurry behind the mill and maintaining the desired value of the latter, in order to improve the accuracy of controlling the drying capacity with restrictions on drying top4 The temperature of the drying agent in the gas inlet shaft is measured and it is maintained with the maximum allowable effect of the drying agent temperature regulator on the actuator mechanism of the flue gas additive, and maintaining the temperature of the azromix behind the mill at the minimum acceptable level is made by changing the fuel consumption by the temperature regulator air mixtures, at the same time disconnect the output of the fuel regulator from the fuel supply device of the mill.