SU922436A1 - Method of automatic regulation of burning in drum boiler fire box - Google Patents

Description

(SM METHOD FOR AUTOMATIC REGULATION OF THE COMBUSTION PROCESS IN THE TOP OF THE DRUM BOILER

I

The invention relates to the automatic regulation of the combustion process in furnaces of drum-type water-tube stationary boilers of low and medium pressure.,

A known method of automatically controlling the combustion in the furnace of a drum boiler, provided with a screen, by measuring air flow, oxygen content in exhaust gases and vapor pressure in the drum with a subsequent change in the fuel supply around the perimeter, which characterizes the heat generation in the furnace, and the pressure in the drum, and air supply - according to air consumption and oxygen content, in exhaust gases D.

In the quality of the parameter characterizing the heat dissipation in the furnace, in a known method, fuel consumption is used.

The disadvantage of the known method is the low quality of regulation, caused by the lack of sufficiently accurate and reliable methods for measuring the consumption of solid fuel.

In addition, an additional signal to the signal based on vapor pressure is needed in order to more accurately assess the degree of correspondence between the material and thermal balances in the Kotlas drum.

The purpose of the invention is to improve the accuracy of regulating the combustion process in the furnace of a boiler operating at a variable load.

Claims (3)

The goal is achieved by taking the second signal by steam pressure in the drum, differentiating it and adjusting the flow of fuel and air according to the received signal, as well as measuring the steam content of the coolant in the furnace screen and using this value as a parameter characterizing the heat dissipation in the furnace. The drawing shows a diagram of the device for implementing this capable. The system contains a main regulator 1 with a pressure sensor 2 in the boiler drum and a differentiator 3 connected to the sensor connected to it. 2. The outputs of the main controller 1 are connected to the controller k of the fuel and through the correction device 5 to the controller 6 of air. Sensors. 7, the steam content of the tetonumifier in the furnace screen, the oxygen content in the flue gases and the air flow rate 9 are connected respectively to the fuel controller, the corrective device 5 and the air regulator 6. The regulating authorities 10 for supplying fuel and air 11 are connected to the controllers and 6, respectively. The system works as follows. When the heat output in the boiler furnace changes, for example, due to reduced fuel consumption, changes in fuel calorific value, increase of suction cups into the furnace, etc., the signal from the steam carrier 7 sensor in the furnace screen decreases, which at a constant value of the reference signal the regulator 1 will lead to an increase in the fuel supply by the regulator 2, to a change in the oxygen content in the exhaust gases, corresponding to an increase in the signal from the sensor 8, to the supply of air into the furnace by the regulator 6 by means of the regulator 11 and restoring consequently, a given coefficient of excess air in the boiler furnace. If a change in steam pressure in the boiler drum occurs, caused by a change in steam consumption, then two signals are sent to the input of controller 1: steam pressure from sensor 2 and the rate of pressure change do not add steam to the drum from the differentiator 3. With small changes in the boiler load, these two signals sufficiently fully estimate the heat load of the boiler. The main regulator of the boiler 1 generates a command signal in accordance with the disappearing signal from the differential, which is fed to the fuel and air regulators 6 and 6 for corrective construction to regulators 10 and 11. As a result, the quality of regulation is improved. The invention The method of automatic control of the combustion process in the furnace of a drum boiler, provided with a screen, by measuring the air flow, oxygen content in exhaust gases and vapor pressure in the drum, followed by changing the fuel supply according to the parameter characterizing heat release in the furnace, and the pressure in the drum, and the air supply, in terms of air consumption and oxygen content in exhaust gases, is different. so that, in order to improve the quality of regulation, they take a second signal from the steam pressure in the drum, differentiate it and adjust the flow of fuel and air according to the received signal, and also measure the steam content of the coolant in the furnace screen and use this value as a parameter, characterizing the heat in the furnace. Sources of information taken into account in the examination 1. Fakacs. L. Improving the Efficiency of JndustriaV Bailers by; Mfcrqp.r, OEessor Control. Power, 1977 USA, Vol. 121, rr 11, p. 80-83v 6 n