SU850995A1 - Method of automatic control of burning process in the fire box of gas-mazut steam boiler - Google Patents

Description

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The invention relates to the automatic control of the process of efficiency of combustion in gas-oil steam boilers with natural circulation of water and can be used in industrial heat power engineering.

There is a known method for automatically controlling the combustion process in a gas-oil steam boiler furnace by changing the air flow rates and the curing gases for fuel and air consumption and a correction signal proportional to the free oxygen content in the flue gas.

The disadvantage of this method is that it is not possible to minimize nitrogen oxides in the furnace, and consequently, to minimize emissions of nitrogen emissions to the environment under the conditions of change in the operating modes of the steam boiler.

The purpose of the invention is to reduce emissions of nitrogen oxides into the environment.

This goal is achieved by measuring the concentrations of nitrogen and fuel in the furnace and, by measuring the NELM signals, additionally correct the air and recirculated gas flow rates.

The drawing shows a diagram of a system that implements the proposed method.

The system contains a fuel consumption sensor 1, a total air consumption sensor 2, a sensor 3 of free oxygen in flue gases upstream of the water economizer, a sensor 4 for initial nitrogen concentration, a sensor 5 for the initial fuel concentration, a computing device 6, a setting 7 for estimating the efficiency of the combustion process , automatic regulator 8, directing the gas apparatuses 9 of the blower 15 fan and, directing the apparatuses 10 of the recirculation fan. The control object is the Heater 11 of the steam boiler.

The system works as follows. The signals of the sensors 1 and 2 of the flow come to the input of the automatic controller 8, the signals from the sensors 3-5 to the input of the computing device 6 "simultaneously with the signal from the setting device

Claims (1)

25 7 values of the evaluation of the combustion process, the signal from the output of the computing unit of unit 6 to the input of the automatic controller 8. The signal from the output of the automatic controller 8 performs a change in the direction of the apparatus 9 and 10 of the blower fan and the recirculation fan. With an increase in the sum of the signals at the input of the automatic controller 8, an increase in the signal at its output occurs. As a result of this, the position of the naphtha of the shoes of apparatus 9 and 10 is changed so that the flow of total air is reduced and the flow rate of the cooler gas increases. The signals measured additionally with respect to the initial concentrations of nitrogen and fuel significantly outpace the signal of the free oxygen content in the test gases in front of the iodine economizer and reduce the inertia. This ensures a reduction in emissions of nitrogen oxides into the environment. The invention The method of automatic control of the combustion process in the furnace of a gas-oil steam boiler by changing the flow rates of air and recirculating gases in terms of fuel and air consumption and a correction signal proportional to the content of free oxygen in the flue gases, so that , in order to reduce emissions of nitrogen oxides into the environment, the concentrations of nitrogen and fuel in the furnace are measured and, according to the measured signals, the flow of air and recirculating gases are additionally adjusted. Sources of information taken into account in the examination 1. Automation of large thermal power plants. Ed. MP, ShalEnergi mana, m., 1974, p. 105112. Toplibo air - t®-ffbifiottif gases // Recycling dyno9y9 gozi