SU1100465A1 - Method of controlling feed of fuel of variable ash content to boiler furnace - Google Patents

Abstract

THE METHOD OF REGULATING THE SUPPLY OF FUEL OF VARIABLE BATTERY IN THE BOILER TOPOKU when using two fuels with different ash by changing the flow rate of each of them according to the temperature in the combustion chamber, characterized in that fuel of lower ash content is determined, the ash content of the mixture obtained is determined, it is compared with the target one, and the difference signal is used to regulate the flow of fuel of low ash content.

Description

The invention relates to thermal energy and can be used in the technology of preparation and compression of coal in boiler plants with liquid slag removal.

There is a known method of controlling the supply of variable ash to the boiler furnace when using two fuels with different ash contents by varying the flow rate of each of them according to the temperature in the combustion chamber 1.

The analysis of the operation experience of boilers for burning slag fuels by varying the ash content and the results of scientific research suggests that an increase in the ash content of fuel A in a certain range of its change leads to a significant increase in the temperature of the normal liquid slag slag fuel.

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melt ia.x, which dramatically affects the yield of liquid landings and reduces the reliability of the boiler. The use of the known method for regulating the supply of slagging fuels to the furnace results in fuel being supplied to the furnace with an increased t, and under conditions of a reduced flame temperature in the furnace. Thus, the disadvantages of this method are the deterioration of the liquid slag yield and the decrease in the reliability of the boiler operation.

The purpose of the invention is to increase the reliability of the boiler by improving the yield of liquid slag.

The goal is achieved by the fact that according to the method of controlling the supply of variable ash to the boiler furnace when using two fuels with different ash by changing the flow rate of each of them according to the temperature in the combustion chamber, lower ash content is added to the high ash fuel, the ash content determined mixture, compare it with a given and on the difference signal regulate the flow of fuel of low ash.

The drawing shows a schematic diagram of an installation for carrying out the proposed method.

The installation includes high-ash coal feed mechanisms 1 on the first conveyor 2, a crushing device 3 placed between the first 2 and second 4 conveyors, a raw coal bunker 5 attached to the dust-preparation unit 6 at the bottom, and the dust pipe 7 to the boiler burners. In addition, the installation contains mechanisms 8 for supplying low-ash coal to warehouse 9, mechanisms 10 for supplying this coal from a warehouse to the first conveyor 2 located in the lower part of the warehouse, the ash sensor 11 coal installed in the coal layer on the second conveyor and connected by a pulse line 12 with a regulator 13, an actuator 14 connected to the controller 13 and the mechanisms 10.

The method is carried out as follows.

The main stream of coal, the ash content of which is higher than the boundary, equal, for example, to 8–8.5% for Kansk-Achinsk coals, is fed by mechanisms 1 to the first conveyor 2, to the crushing device 3, to the second conveyor 4, from where it is dumped into the bunker 5 raw coal . From the bunker, the coal is fed to the dust preparation installation 6, where the coal is ground and the coal is ground. The resulting coal dust is fed through the dust line 7 to the burners of the boiler and burned. The mineral part of the fuel, which separates into the slag under the furnace, melts and flows through the slag tap into the slag-granulator bath, from which the cooled slag is evacuated outside the boiler. An additional flow of coal, the ash content of which is less than the boundary, is supplied by mechanisms 8 to the warehouse 9, from where the mechanisms 10 are fed to the first conveyor 2.

0 In the crushing device 3, in the process of crushing, this coal is mixed with the main stream of coal and then, in a mixture according to the above scheme, the preparatory unit 6 is fed into the dust, the burners of the boiler are burned. Low-ash fuel is added to the high ash to obtain the fuel mixture of the boundary ash content, which is determined at the point of minimum temperature of the normal liquid slag melt according to the schedule for the dependence of t on the ash content of the burned mixture.

Q To automatically provide the required proportion of mixed fuels in the example of a specific implementation of the proposed method, the sensor 11 outputs a continuous signal for the ash content of the coal mixture entering the hopper 5 and further into the furnace, and sends a control line 13 through the pulse line 12 to the regulator. and passes it to the executive mechanism 14, which acts on the mechanisms 10, turning them on or off. The regulator 13 is configured so that it gives "zero command

0 to the actuator 14, if the ash content of the incoming mixture is boundary. In this case, the number of enabled mechanisms 10, as well as their forcing, remain unchanged. If the ash content of the coal mixture begins to grow, the sensor 11 generates the appropriate signal and the control system includes one or several mechanisms 10, or increases their forcing by the consumption of coal. As a result, the consumption of coal from warehouse 9 to the conveyor 2 increases and the ash content of the mixture

0 coals are reduced. The autoregulation process continues until the ash content of the mixture becomes equal to the boundary ash content. If the ash content of the coal mixture is reduced, the autoregulation system affects the mechanisms 10

5 in the opposite direction, reducing their frsirovka or turning off one or more mechanisms, ultimately providing the boundary ash content of the feed mixture.

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Adding to the high-ash fuel an auto-regulation of the flow of low-ash light ash reduces the ash fuel provides stabilization

mixes. The process is carried out until the ash content of the fuel entering the boiler

until the ash content of the mixture becomes equal to the gra-at the boundary level corresponding to 1N., min.

a one that meets the minimum tempera- ture — it provides for the melting.

round of liquid slag removal 5 of slag formed from burning fuel

slag melt. Further adding to the firebox, which improves the entry of liquid slag

low ash fuel is terminated. This also increases the reliability of the boiler.

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Claims (1)

METHOD FOR REGULATING FUEL VARIABLE GOLD IN THE BOILER BOILER when using two fuels with different ash content by changing the flow rate of each of them according to the temperature in the combustion chamber, characterized in that, in order to increase the reliability of the boiler by improving the output of liquid slag, lower ash fuel is added to the high ash fuel, determine the ash content of the resulting mixture, compare it with the given one and use the differential signal to control the fuel supply of low ash content.