SU1483183A1 - Method of controlling combustion air supply - Google Patents

Abstract

The invention can be used in industrial areas associated with emissions of combustion products of fuel into the atmosphere, for example, in heat and power engineering and in public utilities. The task of reducing the harmful effects of flue gases on the environment, especially under adverse weather conditions to disperse harmful impurities in the atmosphere, is solved by changing the supply of combustion air. To do this, they measure the content of nitric oxide and carbon monoxide in exhaust gases, determine their relationship to environmental standards, taking into account the sulfuric anhydride toxicity coefficients and products of incomplete combustion established for correlation functions and environmental standards, determine the sum of these ratios and the latter adjusts the air supply, and the sign of the corrective action is determined by simultaneously increasing the amount and content of one of the measured components. 1 il.

Description

The invention relates to environmental protection and can be widely used in a number of industries associated with emissions of its products into the atmosphere.

The aim of the invention is to reduce the harmful effects of flue gases on the environment.

The drawing shows a block diagram of a system with which the proposed method is carried out.

The method is carried out as follows.

The task controller G according to the load determines the task for the air flow controller 2 in accordance with the required fuel-air ratios.

Computing device 3 receives signals from sensors 4 and 5 of carbon monoxide and nitrous oxide in the flue gases, determines their relationship to environmental standards, taking into account the carbon monoxide toxicity coefficient and toxicity coefficient established by correlation dependencies and environmental standards. of sulfuric anhydride on nitric oxide and in proportion to the sum of these relations forms a correction signal, to controller 2, associated with sensor 6 for air flow, the sign of which t for the simultaneous increase in the amount and content of one of the measured components.

J

00 OE

00 00

3 14831

Toxicity index

gases is determined by n,,

and - T - and - 4- and

i-t N ,.

where AJ is the content of the 1st substance

in exhaust gases, for example in bulk

percent or its concentration in

g / m3; 10

A d

L 1 V A b-i

And, respectively, the values of the concentrations of CO, S03 NOX;

N. - the environmental standard for the 1st substance, established, for example, on the emission from a source into the atmosphere or on the content in the atmospheric air and taking into account the degree of increase in the harmful effects of an increase in the content of the 1st substance above the limit values.

The entire set of harmful products of incomplete combustion of fuel, for example, fuel oil — carbon monoxide, soot, benzo (a) pyrene, and other components, some of which are currently not automatically controlled, can be taken into account by using the correlation functions f ,,, , .., f г св g, the bindings are the content of each, and these substances with the content of carbon monoxide (for the selected fuel). Similarly, the dependence of f ?, is established between the contents of nitric oxide and sulfuric anhydride with various excesses of air supplied for combustion.

To each measured value of carbon monoxide, the toxicity coefficient of products of incomplete combustion of fuel is assigned.

Јi

f-tl

to

and. e

I-. Ni

(2)

Similarly, for nitric oxide, the sulfuric anhydride toxicity coefficient

Bo,

i fi

Ј, N;

(3)

Formula (1) is written in a form suitable for its use in the operation of a computing device by two signals from the primary

sensors

P

and ЈГГ sokn.e + but-to in $,

(BUT)

0

5 0 5

0

five

0

five

83

. where CO and N0 are the concentrations of oxides of carbon and nitrogen.

A correction signal is generated in the computing device when the amount increases by simultaneously increasing the content in the exhaust gases of one of the measured components: CO to increase the air supply, N0 to decrease the air supply to fuel combustion.

Claims (1)

Invention Formula The method of controlling the air supply to the combustion of fuel, including the formation of a signal for setting the air flow rate in accordance with the heat load of the furnace, measuring the concentration of nitric oxide and carbon monoxide in exhaust flue gases, determining the ratio of these concentrations of gases to their maximum permissible values the ratio of the signal that corrects the air flow, the measurement of the actual air flow and its regulation in accordance with the sum of the signals for setting the air flow rate and the corrective Significantly, in order to reduce the harmful effects of flue gases on the environment under adverse weather conditions, the maximum permissible concentrations of nitric oxide and carbon monoxide are set in accordance with environmental standards for emissions of these gases or their content in the atmosphere, taking into account correlation between the concentrations of nitric oxide and carbon monoxide with the toxicity of the resulting combustion products is additionally determined separately for nitric oxide and carbon monoxide exceeding the concentrations of these gases above their maximum permissible values, with a simultaneous increase in the value of the correction signal and when the concentration of carbon monoxide exceeds the maximum permissible value, establish the sign of the correction signal corresponding to an increase in the air flow and with a simultaneous increase in the value of the nitrogen oxide at the maximum permissible the values set the sign of the correction signal corresponding to a decrease in air flow. J f3L