SU767464A1 - Method for automatically controlling combustion conditions in steam generator - Google Patents

Description

one

This invention relates to the automation of the process of burning fuel in steam generators.

There is a known method for automatically adjusting the combustion process of a steam generator by changing the supply of fuel, air and the amount of flue gases removed by the reference signal, fuel consumption and air consumption, and adjusting the supply of air by the signal containing tO NIN oxygen in the exhaust gases, and the amount of flue gases removed by their consumption and vacuum in the furnace 1.

The disadvantage of the known method is the dependence of the dynamic and static-15 accuracy of maintaining the specified ratio of fuel and air consumption on the measurement error of these. costs, which is almost impossible to reduce.20

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

The goal is achieved by the fact that the signal of oxygen content in exhaust gases, taken with the opposite sign, 25 is additionally fed to the fuel supply correction, which is also affected by a signal proportional to the negative pressure in the furnace, and this signal is sent to the air supply correction , additionally also adjusted for the consumption of flue gases.

The imp is a block diagram of an automatic control system for the combustion process.

The fuel consumption regulator 1 is connected to the setting device 2, the fuel consumption sensor 3, the comparison unit 4 connected to the sensor 3, the air consumption sensor 5 and the corrective device 6 of the oxygen content in the exhaust gases, as well as to the adder 7, to the inlet of which the sensor 3, the sensor 8 of the flue gas consumption, and the device 9 mismatch of fuel consumption and flue gases from the set values. A control unit 2, a comparison unit 4, a sensor 5 and a measuring unit 11 with sensors 5 and 8 and a rarefaction sensor 12 are connected to the common air flow controller 10. A controller 2, an adder 7, a sensor 8, and a measuring unit 11 are connected to the controller 13 of the section 13.

The system works as follows.

When the setpoint changes, the signal from setpoint 2 simultaneously enters regulators 1, 10, and 13, which. Carry out proportional changes in fuel, air and flue gas flow rates. If the proportionality is violated (due to inaccurate measurement of fuel consumption, and exhaust gases or other causes), at the outputs of the comparison unit 4, the adder 7 and the measuring unit

11 signals are presented that adjust the operation of the regulators 1, 10 and 13.

The proportionality of the change in fuel and air consumption is provided by a correction device 6 of oxygen content in flue gases.

The proportional change in the flow rates of total air and exhaust gases provides a signal from the sensor.

12 rarely. The proportionality of changes in fuel and flue gas consumption provides a signal from the instrument. 9, characterization of the discrepancy between these costs.

Thus, this method improves the accuracy of controlling the combustion process due to the more accurate maintenance of the ratio of fuel consumption to air flow to flue gas flow.

Claims (1)

1. Automation of large thermal power plants. Under total ed. Ialanna M.P. M., Energie, 1974, p. 96 - 100.