CN212361994U - Coal-fired boiler with main and auxiliary furnaces - Google Patents

Abstract

The utility model relates to a take coal fired boiler of main and auxiliary furnace, including the main furnace, auxiliary furnace and induced draft system, main furnace and auxiliary furnace set up respectively in combustion furnace and separated by middle barricade each other, main hood and main air distribution plate are located the top of main furnace plenum, vice hood, vice air distribution plate is located the top of auxiliary furnace plenum, the coal bed of burning usefulness is respectively at the top burning of main hood and vice hood, the part burning coal charge that is located main furnace crosses middle barricade entering auxiliary furnace in the effect of main furnace forced draught blower wind pressure and continues the burning, set up intercommunication main furnace and auxiliary furnace's inner loop channel on middle barricade, the inner loop channel mouth that is located auxiliary furnace side is higher than the inner loop channel mouth that is located main furnace side, make the burning coal charge that is located auxiliary furnace continue the burning in falling into main furnace through the inner loop channel is automatic. The utility model discloses regard as bed material with cold sediment to the charcoal ignites as the ignition source, reduces the ignition cost, improves the success rate of igniteing.

Description

Coal-fired boiler with main and auxiliary furnaces

Technical Field

The utility model belongs to the technical field of boiler combustion, in particular to coal fired boiler who takes main and auxiliary furnace.

Background

The ignition method of the existing common boiling boiler comprises the following steps: laying hot furnace slag on an air distribution plate, laying bamboo charcoal on the hot furnace slag, igniting to form a charcoal fire layer, generating a micro negative pressure of-10 Pa to 50Pa in a hearth, starting an air blower to enable the charcoal fire layer to slightly jump and not to be buried by the furnace slag, uniformly spreading crushed coal on the charcoal fire layer and gradually increasing air volume to enable the temperature of a material layer to rise. When the air output reaches the minimum air speed in normal operation, the temperature rising speed of the material layer is kept by the quantity of the scattered crushed coal; when the temperature of the material layer reaches 600-700 ℃, increasing the amount of crushed coal and the amount of supplied air to enable the air speed to exceed the minimum air speed within 5 s; when the temperature of the material layer reaches 750-800 ℃, keeping the adding amount of the crushed coal and the air supply amount unchanged to enable the temperature to rise stably; when the temperature of the material layer reaches 800-850 ℃, starting a coal feeder to feed coal normally, keeping the air supply quantity unchanged, and adjusting the combustion condition until the flame is stabilized in golden yellow.

The existing ignition method of the boiling boiler has the following defects:

1. the bottom needs to be paved by hot furnace slag, so that the difficulty is high for a small enterprise with only one boiler, and the potential safety hazard exists because the hot furnace slag needs to be fed manually when being paved on the air distribution plate;

2. the existing coal-fired boiler with a main furnace and an auxiliary furnace is characterized in that the main furnace is small, the auxiliary furnace is large, the problems of coking, extinguishing and the like are easily generated due to operation in the ignition process of the main furnace, and the coking phenomenon is easily generated due to unbalanced air volume control in the ignition process of the auxiliary furnace, so that the integral output of the boiler is influenced;

3. when the boiler is just started, the boiler is influenced by the boiling degree of a material layer, the actual temperature of the material layer has larger deviation with the temperature of an instrument, and for ignition, the problems of low-temperature extinguishing and high-temperature coking exist, and the temperature cannot be used as the only standard for adjusting air supply and coal supply.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a coal fired boiler of taking main and auxiliary furnace is provided, regard the bed material with cold sediment to the charcoal is as the ignition source, ignites the differential bed boiler of height, reduces the ignition cost, improves the success rate of igniteing.

The utility model is realized in such a way, the utility model provides a coal-fired boiler with a main furnace and an auxiliary furnace, which comprises a main furnace, an auxiliary furnace and an air inducing system, wherein the main furnace comprises a main furnace chamber, a main blast cap, a main air distribution plate, a main furnace chamber and a main furnace blower, the auxiliary furnace comprises an auxiliary furnace chamber, an auxiliary blast cap, an auxiliary air distribution plate, an auxiliary furnace chamber and an auxiliary furnace blower, a combustion furnace chamber enclosed by furnace walls is arranged in the coal-fired boiler, the main furnace chamber and the auxiliary furnace chamber are respectively arranged in the combustion furnace chamber and are separated by a middle retaining wall, the main furnace chamber is communicated with an external main furnace blower through a main furnace blast pipe, the main blast cap and the main air distribution plate are arranged at the top of the main furnace chamber, the auxiliary furnace chamber is communicated with the external auxiliary furnace blower through an auxiliary furnace blast pipe, the auxiliary blast cap and the auxiliary air distribution plate are arranged at the top of the auxiliary furnace chamber, a coal layer for combustion is respectively combusted at the top of the main blast cap and the auxiliary blast cap, partial combustion coal material in the main furnace chamber passes through the middle to, the furnace wall of the main furnace is respectively provided with a coal outlet and a main furnace door, the middle baffle wall is provided with an internal circulation channel for communicating the main furnace and the auxiliary furnace, the internal circulation channel positioned at the side of the auxiliary furnace is higher than the internal circulation channel positioned at the side of the main furnace, so that the combustion coal positioned at the auxiliary furnace automatically falls into the main furnace through the internal circulation channel to continue to burn, and a buried pipe internally containing a heating working medium is arranged in the auxiliary furnace.

Further, the coal fired boiler also includes a back flue separator for collecting fine particulate dust that is not burned out of the boiler flue gas.

Further, the main furnace further comprises a main furnace slag discharging pipe, the auxiliary furnace comprises an auxiliary furnace slag discharging pipe, the main furnace slag discharging pipe is communicated with the main hearth, the auxiliary furnace slag discharging pipe is communicated with the auxiliary hearth, and a material returning opening and an auxiliary furnace door are arranged on a furnace wall of the auxiliary hearth.

Furthermore, the main furnace is located on the left side of the combustion furnace, the auxiliary furnace is located on the right side of the combustion furnace, the coal feeding port is formed in a furnace wall on the left side of the main furnace, the main furnace door is respectively arranged on a front side furnace wall and/or a rear side furnace wall of the main furnace, the material returning port is arranged on a furnace wall on the right side of the auxiliary furnace, and the auxiliary furnace door is respectively arranged on a front side furnace wall and/or a rear side furnace wall of the auxiliary furnace.

Further, the height of the material returning opening is higher than that of the coal burning layer in the auxiliary hearth.

Further, the setting height of the coal outlet is higher than the height of the combustion coal layer in the main hearth.

Compared with the prior art, the utility model discloses a coal fired boiler of taking main and auxiliary furnace has following characteristics:

1. the cold slag is used as a bed material, so that the safety is improved;

2. charcoal is used as an ignition source, so that the ignition cost is reduced;

3. the success rate is improved by taking the color of the flame as the basis for finishing the ignition stage;

4. the wind distribution uniformity test and the cold test are carried out by using the same batch of bed materials, so that the labor is reduced;

5. the heat value of the ignition coal only needs about 5000 kilocalories, the heat value range of fuel supply is expanded, and the ignition cost is reduced;

6. in the process of igniting the furnace, the temperature of the furnace is controlled to fall and rise by using cold slag and crushed carbon, so that large-area coking caused by short circuit of air supply and extinguishing caused by too fast lifting of air supply of a hearth are avoided.

Drawings

FIG. 1 is a schematic structural view of a preferred embodiment of a coal-fired boiler with primary and secondary boilers according to the present invention.

Detailed Description

In order to make the technical problem, technical solution and advantageous effects to be solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to illustrate the present invention in further detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, the preferred embodiment of the coal-fired boiler with primary and secondary boilers of the present invention includes a primary boiler 1, a secondary boiler 2, and an air induction system (not shown). The main furnace 1 comprises a main hearth 3, a main hood 4, a main air distribution plate 5, a main furnace air chamber 6, a main furnace air feeder 7 and a main furnace slag discharge pipe 8, and the auxiliary furnace 2 comprises an auxiliary hearth 9, an auxiliary hood 10, an auxiliary air distribution plate 11, an auxiliary furnace air chamber 12, an auxiliary furnace air feeder 13 and an auxiliary furnace slag discharge pipe 14. The arrows in the figure show the direction of flow of the burning coal.

A combustion hearth 16 surrounded by furnace walls 15 is arranged in the coal-fired boiler, and the main hearth 3 and the auxiliary hearth 9 are respectively arranged in the combustion hearth 16 and are separated from each other by an intermediate retaining wall 17. The main furnace air chamber 6 is communicated with an external main furnace blower 7 through a main furnace air pipe 18, and the main air cap 4 and the main air distribution plate 5 are positioned at the top of the main furnace air chamber 6. The auxiliary furnace wind chamber 12 is communicated with an external auxiliary furnace blower 13 through an auxiliary furnace wind pipe 19, and an auxiliary wind cap 10 and an auxiliary wind distribution plate 11 are positioned at the top of the auxiliary furnace wind chamber 12. The coal layer A for combustion is combusted at the top of the main hood 4 and the secondary hood 10 respectively.

The partially combusted coal in the main hearth 3 passes through the intermediate retaining wall 17 under the action of the wind pressure of the main furnace blower 7 and enters the auxiliary hearth 9 for continuous combustion. The furnace wall 15 of the main furnace 3 is respectively provided with a coal outlet 20 and a main furnace door 21, the intermediate retaining wall 17 is provided with an internal circulation channel 22 communicating the main furnace 3 and the auxiliary furnace 9, and the internal circulation channel opening at the side of the auxiliary furnace 9 is higher than the internal circulation channel opening at the side of the main furnace 3, so that the burning coal at the auxiliary furnace 9 automatically falls into the main furnace 3 through the internal circulation channel 22 to continue burning.

A buried pipe 23 containing a heating working medium is arranged in the auxiliary hearth 9. The coal-fired boiler heats the working medium in the buried pipe 23.

Finer particles in the burning coal material of main furnace 3 cross middle retaining wall 17 under the effect of main furnace forced draught blower 7 wind pressure and get into and pile up in the auxiliary furnace 9 to the working medium in the pipe laying 23 heats, and the bed material of auxiliary furnace 9 reaches the fluidization state back under the effect of auxiliary furnace forced draught blower 13, can fall into main furnace 3 through inner circulation passageway 22 automatically and fully burn again, and the burning coal material accomplishes an inner loop at burning furnace 16.

The main furnace slag discharging pipe 8 is communicated with the main hearth 3, the auxiliary furnace slag discharging pipe 14 is communicated with the auxiliary hearth 9, and a material returning port 24 and an auxiliary furnace door 25 are arranged on a furnace wall 15 of the auxiliary hearth 9. The main furnace slag discharging pipe 8 is used for discharging burnt coal slag in the main furnace 3, and the auxiliary furnace slag discharging pipe 14 is used for discharging burnt coal slag in the auxiliary furnace 9.

The coal-fired boiler also comprises a rear flue separator 26 for collecting fine particle dust which is not burnt out in the boiler flue gas, and the fine particle dust collected by the rear flue separator 26 enters the auxiliary hearth 9 through the return port 24 to be continuously combusted and utilized. The process belongs to the external circulation of burning coal particles, so that the coal is fully utilized, and the coal resources are further saved.

As shown in fig. 1, in the present embodiment, the main furnace 3 is located at the left side of the combustion furnace 16, the auxiliary furnace 9 is located at the right side of the combustion furnace 16, the coal feeding port 20 is disposed on the furnace wall 15 at the left side of the main furnace 3, the main furnace doors 21 are respectively disposed on the front side furnace wall and/or the rear side furnace wall of the main furnace 3, the material returning port 24 is disposed on the furnace wall 15 at the right side of the auxiliary furnace 9, and the auxiliary furnace doors 25 are respectively disposed on the front side furnace wall and/or the rear side furnace wall of the auxiliary furnace 9.

Specifically, the height of the material returning opening 24 is higher than the height of the combustion coal layer a in the auxiliary hearth 9. The lower coal port 20 is higher than the combustion coal layer A in the main hearth 3.

The utility model also discloses a coal fired boiler's of taking main and auxiliary furnace ignition method as before, including following step:

step one, paving a base material in the main hearth 3, uniformly paving the cold slag on a main hood 4 at the bottom of the main hearth 3 to be used as the base material, wherein the paving thickness is 450-500 mm.

And (3) paving a base material, and completely removing ironware and slag between the main air caps 4 to avoid local fluidization state unbalance caused by blockage of the main air caps 4.

Wherein, the cold slag is the coal slag which is discharged from a high-low differential bed boiler and is sieved, the proportion of the granularity between 0.1mm and 8mm accounts for more than 85wt% of the total amount, and the maximum granularity does not exceed 10 mm.

The main furnace blower 7 is turned on to carry out the air distribution uniformity test and the cold test and then turned off. The boiling uniformity of the cold slag bed charge at each position in the main hearth 3 is checked by increasing the air output of the main furnace blower 7, and the boiling dead zone is eliminated. The critical cold-state boiling air volume is determined by reducing the air volume of the main furnace blower 7, so that the lowest air volume during hot-state operation is estimated, and the phenomenon that the air volume is too large during hot-state operation, so that the cold slag is covered with red carbon to cause extinguishment is avoided.

And step two, igniting the main hearth 3, opening the main furnace door 21, closing other furnace doors, and starting an induced draft system to ventilate the coal-fired boiler for 4-5 minutes so that the interior of the main hearth 3 is in a micro-negative pressure state. The match or the charcoal is placed in the main hearth 3 and ignited by the ignition material, after the match is burnt into the charcoal or the charcoal is burnt completely, the match or the charcoal is broken and laid on the base material, and the steps are repeated until the charcoal layer reaches the thickness of 80 mm-120 mm. Waiting for 15-25 minutes to allow the charcoal to be red. Wherein, the thickness of the matches or the charcoal is 30 mm-40 mm.

When the charcoal fire is ignited, the opening degree of the main furnace door 21 is adjusted to control the charcoal fire to burn, after the firewood is burnt into the charcoal fire or the charcoal is burnt completely, the rake is used for smashing the larger red charcoal, and the charcoal which is not burnt completely is cleaned out of the main furnace.

And step three, starting a main furnace blower 7, supplying micro wind according to the cold state test result of the step one, enabling the particles of the charcoal fire layer to slightly jump up and down, and adding fine coal to increase wind when the red fire waves are reduced in the particles of the charcoal fire in the furnace. However, at this time, the furnace temperature is not high, and the air volume is not too large, so that the ash particles can only jump up and down, and the ash particles are not suitable to tumble. In the initial stage of ignition, charcoal fire or ignited coal particles are easily submerged to cause extinguishment, so that the motion state of the furnace charge is carefully observed, sometimes, too many combustible fine particles are contained in the bottom material, the ignition is fast, the heat release in the furnace is large, the furnace is boiled and combusted at a lower wind speed to cause deflagration, the temperature rise is too fast, sometimes, the wind quantity is too large, the ignited fine particles and the heat in the furnace can be instantly and greatly flown out of the furnace, and the unburned coarse coal particles which are not flown away are covered by the bottom material, at the moment, if no measures are taken, the fire light disappears during turning, and the temperature is greatly reduced or even extinguished; on the contrary, if the air quantity of the main furnace is too small, floating coke is formed on the surface of the bed material, the continuous process of the exchange process of the material layer is influenced, when 'blow-out' or 'meteor' occurs in the furnace, the phenomenon of coking is often represented, a rake is used for removing coke blocks in time, and the opening degree of the furnace door is adjusted. When the furnace temperature rises slowly, the air can be continuously added to feed coal, and when the temperature of the material bed is not uniform, the material bed can be stirred manually. The fire waves jump more and more along with the ignition and combustion of the fine coal, which shows that the mass exchange of the coal in a boiling state gradually expands downwards, and the bottom bed charge starts to combust because of the strong heat exchange brought by the mass exchange of the upper and lower hot materials.

The heat value of the fine coal is 5000 +/-200 KJ/Kg, the proportion of the granularity between 0.1mm and 8mm accounts for more than 80 percent of the total amount, the maximum granularity is not more than 15mm, and the volatile matter is less than 11 percent.

When the furnace temperature of the main furnace 3 reaches 400-500 ℃, the flame is converted from dark red to apricot yellow, and the fine coal is added with wind, so that the added fine coal is quickly ignited and burnt, and the furnace temperature is also quickly increased.

When the furnace temperature of the main furnace 3 reaches 600-700 ℃, the flame is brighter and brighter, the material layers are apricot-yellow, the fluidization state of the fire coal reaches above 2/3 (the upper material layer is fluidized after 300 mm), the fluidization state is further expanded downwards, the mass exchange between the upper layer and the lower layer is further strengthened, the mass exchange in the horizontal direction is strengthened, the mass exchange is expanded to the whole main air distribution plate 5, and at the moment, the main furnace door 21 is closed. And starting the coal feeder, adding fine coal through the coal outlet 20, switching to the normal operation of 70% of coal feeding amount, and gradually increasing to normal according to the furnace temperature. Under the blowing action of the main furnace blower 7, the partially combusted coal which jumps up and down in the main hearth 3 continuously crosses the intermediate retaining wall 17 to enter the auxiliary hearth 9 to be accumulated and continuously combusted.

When the temperature of the main hearth rises to over 800 ℃, the flame is orange yellow, and when the temperature difference between the upper, middle and lower three points of the coal fluidized layer is less and less, the ignition of the main hearth 3 is finished. The rakes are used for swinging between bed materials, and if the swinging resistance is small and the rakes touch the main blast cap 4, the whole bed material of the main hearth 3 is in a fluidized state.

And step four, igniting the auxiliary furnace 2, enabling the main hearth 3 to stably run for 8 hours, starting an auxiliary furnace blower 13 when the bed material accumulation in the auxiliary hearth 9 reaches the height of the middle retaining wall 17, slowly increasing the air volume to be normal, burning the bed material in the auxiliary hearth 9 to be in a fluidized state, automatically dropping part of burning coal into the main hearth 3 through the internal circulation channel 22 to continue burning, and finishing the internal circulation of the burning coal. When the air quantity of the main hearth 3 and the current of the main furnace blower 7 do not fluctuate obviously, the success of the point furnace of the auxiliary furnace 2 is shown, the bed combination of the main hearth 3 and the auxiliary hearth 9 is successful, and the whole ignition process is finished.

After the combined bed of the main hearth and the auxiliary hearth is successfully and stably operated, unburnt fine particle dust in the boiler flue gas collected by the rear flue separator enters the auxiliary hearth through the return port to be continuously combusted and utilized, and the process is the external circulation of coal.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims (6)

1. A coal-fired boiler with a main furnace and an auxiliary furnace comprises a main furnace, the auxiliary furnace and an air induction system, and is characterized in that the main furnace comprises a main hearth, a main hood, a main air distribution plate, a main furnace air chamber and a main furnace air feeder, the auxiliary furnace comprises an auxiliary hearth, an auxiliary hood, an auxiliary air distribution plate, an auxiliary furnace air chamber and an auxiliary furnace air feeder, a combustion hearth surrounded by furnace walls is arranged in the coal-fired boiler, the main hearth and the auxiliary hearth are respectively arranged in the combustion hearth and are separated by a middle retaining wall, the main furnace air chamber is communicated with the external main furnace air feeder through a main furnace air pipe, the main hood and the main air distribution plate are positioned at the top of the main furnace air chamber, the auxiliary furnace air chamber is communicated with the external auxiliary furnace air feeder through an auxiliary furnace air pipe, the auxiliary hood and the auxiliary air distribution plate are positioned at the top of the auxiliary furnace air chamber, coal layers for combustion are respectively combusted at the tops of the main hood and the auxiliary hood, partial combustion coal materials in the main hearth enter the auxiliary hearth to continuously combust through the middle retaining wall under the action of, the furnace wall of the main furnace is respectively provided with a coal outlet and a main furnace door, the middle baffle wall is provided with an internal circulation channel for communicating the main furnace and the auxiliary furnace, the internal circulation channel positioned at the side of the auxiliary furnace is higher than the internal circulation channel positioned at the side of the main furnace, so that the combustion coal positioned at the auxiliary furnace automatically falls into the main furnace through the internal circulation channel to continue to burn, and a buried pipe internally containing a heating working medium is arranged in the auxiliary furnace.

2. A coal-fired boiler with primary and secondary boilers as claimed in claim 1, characterized in that the coal-fired boiler further comprises a back flue separator for collecting fine particulate dust that is not burned out of the boiler flue gases.

3. The coal-fired boiler with the main and auxiliary furnaces as claimed in claim 1, wherein the main furnace further comprises a main furnace slag discharging pipe, the auxiliary furnace comprises an auxiliary furnace slag discharging pipe, the main furnace slag discharging pipe is communicated with the main hearth, the auxiliary furnace slag discharging pipe is communicated with the auxiliary hearth, and a material returning port and an auxiliary furnace door are arranged on the furnace wall of the auxiliary hearth.

4. The coal-fired boiler with the main and auxiliary furnaces as claimed in claim 3, wherein the main furnace is located at the left side of the combustion furnace, the auxiliary furnace is located at the right side of the combustion furnace, the lower coal ports are provided on the wall at the left side of the main furnace, the main furnace doors are respectively provided on the front side wall and/or the rear side wall of the main furnace, the material returning ports are provided on the wall at the right side of the auxiliary furnace, and the auxiliary furnace doors are respectively provided on the front side wall and/or the rear side wall of the auxiliary furnace.

5. A coal-fired boiler with main and auxiliary furnaces as claimed in claim 3, characterized in that the level of the return port is set higher than the level of the layer of the combustion coal in the auxiliary furnace.

6. The coal-fired boiler with primary and secondary furnaces as claimed in claim 1, wherein the lower ports are provided at a height higher than that of the layer of the combustion coal in the main furnace.

Images