Coal-fired boiler

Abstract

The utility model relates to a coal-fired boiler, and relates to the technical field of industrial boilers, the coal-fired boiler comprises a separator communicated with a hearth, the top of the separator is communicated with a flue with a vertical tail, the tail end of the flue is sequentially connected with a dust remover and an induced draft fan, and the induced draft fan is provided with a flue gas recirculation mechanism used for circulating part of discharged flue gas into the hearth. The flue gas recycling mechanism comprises a circulating pipe, a gas inlet pipe and a gas outlet pipe, wherein the circulating pipe is used for discharging part of flue gas discharged by the induced draft fan into the hearth; the circulating fan is used for adjusting the flue gas flow and air pressure in the circulating pipe; and the anti-backflow assembly is used for preventing hearth bed materials and smoke thereof from flowing backwards into the circulating pipe. Part of flue gas in the induced draft fan is discharged back into the hearth through the circulating pipe by the circulating fan, so that the overall furnace temperature is kept balanced, and the combustion process of the whole boiler has the best efficient low-nitrogen combustion behavior; and meanwhile, when the circulating fan is closed, the anti-backflow assembly prevents bed materials in the hearth from entering the circulating pipe, and the temperature stability and the environment-friendly performance of the boiler are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial boilers, in particular to a coal-fired boiler. BACKGROUND

[0002] Coal-fired boilers are widely used in industrial production and residential heating, but under the background of increasing environmental pressure, traditional coal-fired boilers face many challenges. On the one hand, a large amount of pollutants such as sulfur dioxide, nitrogen oxides and dust are produced during the combustion process of coal-fired boilers, causing serious pollution to the environment; on the other hand, with the proposal of the national "carbon peak and carbon neutral" goal, traditional coal-fired boilers have been unable to meet the requirements of energy saving and emission reduction. Therefore, how to ensure the heating capacity while reducing environmental pollution has become a problem to be solved.

[0003] At present, in order to solve the above problems, the following methods are proposed:

[0004] 1. Biomass mixed combustion: biomass fuel is mixed with coal for combustion, which can reduce carbon dioxide emissions to a certain extent, but due to the low calorific value of biomass fuel, it is difficult to promote on a large scale;

[0005] 2. Flue gas purification technology: by increasing flue gas purification equipment such as desulfurization tower and dust remover to reduce pollutant emissions. However, the investment cost of these equipment is high, the maintenance is complex, and it cannot fundamentally solve the problem;

[0006] 3. Circulating fluidized bed technology: adopt circulating fluidized bed boiler, increase the proportion of solid waste fuel blending, improve the combustion efficiency and heat utilization rate. However, the existing circulating fluidized bed boiler still has some problems in design and operation, such as unstable furnace temperature control, easy damage of refractory materials, etc.

[0007] Although the above technical means improves the environmental performance of coal-fired boilers to a certain extent, there are still the following defects: the calorific value of biomass mixed combustion is unstable, affecting the stable operation of the boiler; the investment of flue gas purification equipment is high, the operation cost is large, and the economic benefit is poor; the design and operation parameters of circulating fluidized bed boiler are unreasonable, resulting in poor temperature stability inside the boiler and high concentration of nitrogen oxides emission. CONTENT OF THE INVENTION

[0008] In order to improve the stability of boiler temperature and environmental performance, the present application provides a coal-fired boiler.

[0009] The coal-fired boiler provided by the present application adopts the following technical scheme:

[0010] A coal-fired boiler comprises a separator in communication with a furnace, the furnace is provided with an air distribution plate near one side of the bottom, the bottom of the separator is in communication with the furnace through a return plate, the top of the separator is communicated with a tail vertical flue, the tail end of the flue is connected with a dust collector and an induced draft fan in sequence, the induced draft fan is provided with a flue gas recirculation mechanism for circulating part of the exhaust flue gas into the furnace, the flue gas recirculation mechanism comprises:

[0011] A circulating pipe is arranged on the induced draft fan exhaust port, and the circulating pipe is used for discharging part of the flue gas discharged by the induced draft fan into the furnace;

[0012] A circulating fan is arranged on the circulating pipe and is used for adjusting the flow and air pressure of the flue gas in the circulating pipe;

[0013] An anti-backflow assembly is arranged on the side of the circulating pipe close to the furnace and is used for preventing the bed material and its flue gas in the furnace from backflowing into the circulating pipe.

[0014] By adopting the above technical scheme, the fuel is burned in the furnace, the burned flue gas enters the separator for separation, the separated powder is discharged back into the furnace for recombustion after being preheated again, the separated flue gas enters the vertical flue, the flue gas is treated through the flue, and then is discharged into the dust collector for dust removal, and then enters the induced draft fan, the circulating fan discharges part of the flue gas in the induced draft fan back into the furnace through the circulating pipe, which facilitates the discharge of the flue gas in the circulating pipe into the air distribution plate, realizes the balance of the overall furnace temperature, and makes the combustion process of the whole boiler have the best high-efficiency low-nitrogen combustion behavior; at the same time, when the circulating fan is closed, the anti-backflow assembly prevents the bed material in the furnace from entering the circulating pipe, thereby improving the stability and environmental protection performance of the boiler temperature.

[0015] Further, the anti-backflow assembly comprises:

[0016] A sealing purge pipe in communication with the circulating pipe and used for discharging the flue gas in the circulating pipe into the furnace;

[0017] A damper rotatably arranged on the sealing purge pipe, the damper can rotate under the blowing of the flue gas;

[0018] A first limiting block arranged on the side wall of the sealing purge pipe and used for preventing the damper from rotating towards the circulating pipe, the sealing purge pipe is sealed when the damper abuts against the first limiting block;

[0019] A torsional spring arranged on the sealing purge pipe and used for driving the damper to rotate towards the first limiting block.

[0020] By adopting the above technical scheme, when the circulating fan is started, the flue gas in the circulating pipe enters the sealing blowing pipe, and then drives the air door to rotate under the blowing of the air and stores the torsional spring, so as to facilitate the flue gas in the circulating pipe to be discharged into the hearth, and the opening degree of the air door is controlled according to the amount of flue gas in the circulating pipe, when the circulating fan is closed, the torsional spring drives the air door to abut against the first limiting block and seals the sealing blowing pipe.

[0021] Further, the sealing blowing pipe is located on the upper part of the air distribution plate and is used for discharging the flue gas in the circulating pipe into the air distribution plate.

[0022] By adopting the above technical scheme, the sealing blowing pipe is used for discharging the flue gas in the circulating pipe into the air distribution plate, and the air distribution plate is strengthened.

[0023] Further, the rotating shaft of the air door is arranged on the top of the sealing blowing pipe and makes the air door always keep an inclined or vertical state, and a smooth layer is arranged on the side of the air door away from the circulating pipe, which facilitates the bed material on the air door to fall back into the hearth.

[0024] By adopting the above technical scheme, the air door always keeps an inclined or vertical state, which facilitates the bed material attached to the air door to fall back into the hearth, and the smooth layer reduces the probability of the bed material attached to the air door.

[0025] Further, a second limiting block is arranged on the sealing blowing pipe and is used for limiting the side of the air door away from the first limiting block, and the second limiting block is used for preventing the air door from rotating too large.

[0026] By adopting the above technical scheme, the second limiting block is used for preventing the air door from rotating too large, thereby improving the service life of the torsional spring and making the torsional spring always have good rotation.

[0027] Further, the side wall of the hearth is provided with a feeding assembly, and the feeding assembly comprises:

[0028] A coal pre-feeder system is used for providing coal;

[0029] A coal feeding port is arranged on the side wall of the hearth and is used for discharging the coal provided by the coal pre-feeder system into the hearth;

[0030] A solid waste pre-feeder system is used for providing solid waste fuel;

[0031] A solid waste feeding port is arranged on the side wall of the hearth and is used for discharging the solid waste provided by the solid waste pre-feeder system into the hearth.

[0032] By adopting the technical scheme, the coal-fired furnace front feeding system adds the coal into the furnace through the coal feeding port, the solid waste furnace front feeding system adds the solid waste into the furnace through the solid waste feeding port, and then the coal and the solid waste are mixed in the furnace through the air distribution plate, so that the mixed combustion of the coal and the solid waste is realized.

[0033] Further, the solid waste furnace front feeding system is provided with a deodorization assembly, the deodorization assembly is used for discharging the gas generated in the solid waste furnace front feeding system into the furnace, and the deodorization assembly comprises:

[0034] A deodorization pipe is arranged on the solid waste furnace front feeding system and communicates with the inside of the furnace;

[0035] A deodorization fan is arranged on the deodorization pipe and is used for discharging the gas in the solid waste furnace front feeding system into the furnace;

[0036] A one-way valve is arranged on the deodorization pipe and is used only for discharging the gas in the solid waste furnace front feeding system into the furnace by the deodorization pipe.

[0037] By adopting the technical scheme, the deodorization fan discharges the gas in the solid waste furnace front feeding system into the furnace through the deodorization pipe, and the one-way valve prevents the flue gas in the furnace from entering the solid waste furnace front feeding system, so that the gas in the solid waste furnace front feeding system is combusted and utilized and the pollution to the environment is reduced.

[0038] Further, the furnace is provided with a high-temperature screen-type superheater, and the heating surface tube of the high-temperature screen-type superheater is made of TP347 stainless steel.

[0039] By adopting the technical scheme, the high-temperature screen-type superheater made of TP347 stainless steel has strong high-temperature resistance, high-pressure resistance and corrosion resistance.

[0040] In summary, the present application has at least one of the following beneficial technical effects:

[0041] The coal and the solid waste fuel are put into the furnace through the coal feeding port and the solid waste feeding port for combustion, the flue gas after combustion is separated in the separator, the separated powder is discharged back into the furnace for re-combustion after being preheated again, the separated flue gas is discharged into the vertical flue, the flue gas is treated through the flue and then discharged into the dust collector for dust removal, and then into the induced draft fan, the circulating fan discharges part of the flue gas in the induced draft fan back into the furnace through the circulating pipe, and the flue gas in the circulating pipe blows the air door to open, so as to facilitate the discharge of the flue gas in the circulating pipe into the air distribution plate, realize the balance of the overall furnace temperature, and make the combustion process of the whole boiler have the best high-efficiency low-nitrogen combustion behavior; at the same time, when the circulating fan is closed, the torsional spring drives the air door to close, so as to prevent the bed material in the furnace from entering the circulating pipe, and improve the stability and environmental protection performance of the boiler temperature. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a schematic diagram of the structure of a coal-fired boiler of the present application;

[0043] Figure 2 is Figure 1 is a schematic diagram of the cross-section of A-A in FIG.

[0044] Figure 3 is Figure 2 is an enlarged schematic diagram of part B in FIG.

[0045] Figure 4 is a front view of a coal-fired boiler of the present application, wherein the coal-fired furnace front feeding system is not shown.

[0046] Reference signs: 1, furnace; 11, air distribution plate; 12, separator; 13, return plate; 14, flue; 15, dust collector; 16, induced draft fan; 2, flue gas recirculation mechanism; 21, circulation pipe; 22, circulation fan; 3, anti-backflow assembly; 31, sealing purge pipe; 32, damper; 33, first limit block; 4, second limit block; 5, feeding assembly; 51, coal-fired furnace front feeding system; 52, coal feeding port; 53, solid waste furnace front feeding system; 54, solid waste feeding port; 6, deodorization assembly; 61, deodorization pipe; 62, deodorization fan; 63, one-way valve. DETAILED DESCRIPTION

[0047] The following will be described in detail below with reference to the accompanying Figures 1-4 The present application will be described in further detail.

[0048] The present application discloses a coal-fired boiler.

[0049] Reference will be made to Figure 1 and Figure 2 A coal-fired boiler comprises a separator 12 in communication with a furnace 1, the furnace 1 is provided with an air distribution plate 11 near one side of the bottom, the bottom of the separator 12 is in communication with the furnace 1 through a return plate 13, the top of the separator 12 is in communication with a tail vertical flue 14, the tail end of the flue 14 is sequentially connected with a dust collector 15 and an induced draft fan 16, and the induced draft fan 16 is provided with a flue gas recirculation mechanism 2 for circulating part of the exhaust flue gas into the furnace 1.

[0050] Reference will be made to Figure 1 The furnace 1 is used for burning fuel, the flue gas after preliminary combustion and part of the fuel that is not completely combusted enters the separator 12, the flue gas and the powder are separated through the separator 12, the separated powder is discharged back into the furnace 1 after being preheated again for re-combustion, the separated flue gas enters the vertical flue 14, the flue gas is treated through the flue 14 and then discharged into the dust collector 15 for dust removal, and then enters the induced draft fan 16 to discharge the filtered flue gas.

[0051] ReferenceFigure 1 And Figure 2 , the flue gas recirculation mechanism 2 comprises a circulating pipe 21, a circulating fan 22 and an anti-backflow assembly 3, one end of the circulating pipe 21 is fixedly installed on the exhaust fan 16 discharge port, the circulating pipe 21 is used for discharging part of the flue gas discharged by the exhaust fan 16 into the furnace 1, by recirculating part of the flue gas discharged by the exhaust fan 16 back to the furnace 1, and then making the fuel in the furnace 1 burn in a relatively oxygen-deficient environment, the combustion of the fuel is inhibited, avoiding the case that the temperature inside the furnace 1 is too high, and realizing that the overall furnace temperature is balanced, at the same time, the flue gas discharged by the exhaust fan 16 back to the furnace 1 inhibits the combustion inside the furnace 1, and then makes the combustion process of the whole boiler have the best high-efficiency low-nitrogen combustion behavior, so as to reduce the probability of generating nitrogen oxides.

[0052] Referring to Figure 1 , the circulating fan 22 is fixedly installed on the circulating pipe 21, and the circulating fan 22 is used for adjusting the flue gas flow and air pressure in the circulating pipe 21, and then controlling the amount of flue gas entering the furnace 1, so as to control the degree of fuel combustion inside the furnace 1.

[0053] Referring to Figure 2 And Figure 3 , the anti-backflow assembly 3 is arranged on the side of the circulating pipe 21 close to the furnace 1, and the anti-backflow assembly 3 is used for preventing the bed material and its flue gas in the furnace 1 from flowing back into the circulating pipe 21, and the anti-backflow assembly 3 comprises a sealing purge pipe 31, a damper 32, a first limiting block 33 and a torsional spring, the sealing purge pipe 31 is fixedly installed on the furnace 1, and one end of the sealing purge pipe 31 away from the furnace 1 is sealingly connected with the circulating pipe 21, so as to discharge the flue gas in the circulating pipe 21 into the furnace 1, the sealing purge pipe 31 is located on the upper part of the air distribution plate 11, and the sealing purge pipe 31 is used for discharging the flue gas in the circulating pipe 21 into the air distribution plate 11, so as to make the back pressure at the gas outlet of the sealing purge pipe 31 smaller, and strengthen the fluidization of the air distribution plate 11; the damper 32 is rotatably installed on the sealing purge pipe 31, and the damper 32 can rotate under the action of the flue gas, the rotary shaft of the damper 32 and the sealing purge pipe 31 is located on the top of the sealing purge pipe 31, so as to make the damper 32 always keep an inclined or vertical state, and a smooth layer is fixedly installed on the side of the damper 32 away from the circulating pipe 21, the smooth layer has good heat resistance, and at the same time, the smooth layer is relatively smooth, so as to facilitate the bed material falling on the damper 32 to fall back into the furnace 1 in time, and then reduce the probability of the bed material in the furnace 1 entering the sealing purge pipe 31.

[0054] Referring to Figure 2 And Figure 3, the first limiting block 33 is fixedly installed on the side wall of the sealing and purging pipe 31, when the air door 32 abuts against the first limiting block 33, the first limiting block 33 is used for preventing the air door 32 from rotating towards the circulating pipe 21, at this time, the air door 32 seals the sealing and purging pipe 31, thereby preventing the bed material and the flue gas in the hearth 1 from entering the circulating pipe 21; the torsional spring is fixedly installed on the sealing and purging pipe 31, the movable end of the torsional spring is fixedly installed on the rotating shaft of the air door 32, the torsional spring is used for driving the air door 32 to rotate towards the first limiting block 33; specifically, when the circulating fan 22 discharges part of the flue gas in the induced draft fan 16 into the circulating pipe 21, the flue gas enters the sealing and purging pipe 31 and blows on the air door 32, the air door 32 rotates under the blowing of the flue gas and makes the torsional spring elastically deform, and the opening degree of the air door 32 is controlled according to the amount of the flue gas in the circulating pipe 21; when the circulating fan 22 stops, the pushing force of the flue gas on the air door 32 is smaller than the force of the torsional spring and the hearth 1 on the air door 32, the air door 32 rotates towards the first limiting block 33 and abuts against the first limiting block 33, at this time, the pressure in the sealing and purging pipe 31 is smaller than the air pressure in the hearth 1, thereby ensuring the sealing of the air door 32 on the sealing and purging pipe 31.

[0055] With reference to Figure 2 and Figure 3 , the second limiting block 4 is fixedly installed on the sealing and purging pipe 31, the second limiting block 4 is used for limiting the side of the air door 32 away from the first limiting block 33, the second limiting block 4 is used for preventing the air door 32 from rotating too large, thereby prolonging the service life of the torsional spring and making the torsional spring always have good rotation.

[0056] With reference to Figure 1 and Figure 2 , the side wall of the hearth 1 is provided with a feeding assembly 5, the feeding assembly 5 includes a coal pre-feeder system 51, a coal feeding port 52, a solid waste pre-feeder system 53 and a solid waste feeding port 54, the coal pre-feeder system 51 is used for treating the coal and providing the coal into the hearth 1; the coal feeding port 52 is fixedly installed on the side wall of the hearth 1 and located on the air distribution plate 11, the coal feeding port 52 discharges the coal provided by the coal pre-feeder system 51 into the hearth 1 at a certain speed; the solid waste pre-feeder system 53 is used for treating the solid waste and providing the solid waste fuel into the hearth 1; the solid waste feeding port 54 is fixedly installed on the side wall of the hearth 1 and located on the air distribution plate 11, the solid waste feeding port 54 discharges the solid waste fuel provided by the solid waste pre-feeder system 53 into the hearth 1 at a certain speed; thereby making the coal and the solid waste fuel burn in the hearth 1.

[0057] With reference to Figure 1 and Figure 4, solid waste furnace feed system 53 is provided with a deodorization assembly 6, because the solid waste is easy to produce combustible toxic gases such as ammonia and hydrogen sulfide in the treatment process, the gas generated in the solid waste furnace feed system 53 is discharged into the hearth 1 through the deodorization assembly 6, the deodorization assembly 6 includes a deodorization pipe 61, a deodorization fan 62 and a one-way valve 63, the deodorization pipe 61 is fixedly installed on the top of the solid waste furnace feed system 53, and the side of the deodorization pipe 61 away from the solid waste furnace feed system 53 is in communication with the inside of the hearth 1; the deodorization fan 62 is fixedly installed on the deodorization pipe 61, and is used for discharging the gas generated in the solid waste furnace feed system 53 into the hearth 1; the one-way valve 63 is fixedly installed on the side of the deodorization pipe 61 close to the hearth 1, and is used for discharging the gas in the solid waste furnace feed system 53 into the hearth 1 only through the deodorization pipe 61, so as to burn and utilize the gas in the solid waste furnace feed system 53 and reduce the pollution to the environment.

[0058] With reference to Figure 1 , the high-temperature screen-type superheater is arranged in the hearth 1, in order to improve the service life of the high-temperature screen-type superheater, the heat receiving surface pipe of the high-temperature screen-type superheater is made of TP347 stainless steel, thereby enhancing the high-temperature resistance, high-pressure resistance and corrosion resistance of the high-temperature screen-type superheater.

[0059] The working of the embodiment of the present application is as follows:

[0060] The coal and solid waste fuel are put into the hearth 1 through the coal feeding port 52 and the solid waste feeding port 54 for combustion, the flue gas after combustion is separated in the separator 12, the separated powder is discharged back into the hearth 1 after being preheated again for recombustion, the separated flue gas enters the vertical flue 14, the flue gas is treated through the flue 14 and then discharged into the dust collector 15 for dust removal, and then enters the induced draft fan 16, the circulating fan 22 discharges part of the flue gas in the induced draft fan 16 back into the hearth 1 through the circulating pipe 21, and the flue gas in the circulating pipe 21 drives the air door 32 to open, so as to facilitate the discharge of the flue gas in the circulating pipe 21 into the air distribution plate 11, realize the balance of the overall furnace temperature, and make the combustion process of the whole boiler have the best high-efficiency low-nitrogen combustion behavior; at the same time, when the circulating fan 22 is closed, the torsional spring drives the air door 32 to close, so as to prevent the bed material in the hearth 1 from entering the circulating pipe 21, and improve the stability of the boiler temperature and the environmental protection performance.

[0061] The above are the preferred embodiments of the present application, which do not limit the protection scope of the present application, therefore: any equivalent changes made on the structure, shape, working of the present application should be covered into the protection scope of the present application.

Claims

1. A coal-fired boiler comprising a separator (12) in communication with a furnace (1), the furnace (1) being provided with an air distribution plate (11) near one side of the bottom, the bottom of the separator (12) being in communication with the furnace (1) through a return plate (13), and a tail vertical flue (14) being in communication with the top of the separator (12), the end of the flue (14) being connected in turn to a dust collector (15) and an induced draft fan (16), characterized in that: The induced draft fan (16) is provided with a flue gas recirculation mechanism (2) for circulating part of the exhaust flue gas into the furnace (1), the flue gas recirculation mechanism (2) comprises: A circulating pipe (21) is arranged on the exhaust port of the induced draft fan (16), and the circulating pipe (21) is used for discharging part of the flue gas exhausted by the induced draft fan (16) into the furnace (1); A circulating fan (22) is arranged on the circulating pipe (21) and is used for adjusting the flow and pressure of the flue gas in the circulating pipe (21); A backflow prevention assembly (3) is arranged on the side of the circulating pipe (21) close to the furnace (1) and is used for preventing the bed material and flue gas in the furnace (1) from flowing back into the circulating pipe (21).

2. A coal-fired boiler according to claim 1, characterised in that: The backflow prevention assembly (3) comprises: A sealing purge pipe (31) is in communication with the circulating pipe (21) and is used for discharging the flue gas in the circulating pipe (21) into the furnace (1); A damper (32) is rotatably arranged on the sealing purge pipe (31), and the damper (32) can rotate under the action of the flue gas; A first limiting block (33) is arranged on the side wall of the sealing purge pipe (31) and is used for preventing the damper (32) from rotating towards the circulating pipe (21), and the damper (32) is sealed against the first limiting block (33) when the damper (32) abuts against the first limiting block (33); A torsional spring is arranged on the sealing purge pipe (31) and is used for driving the damper (32) to rotate towards the first limiting block (33).

3. A coal-fired boiler according to claim 2, characterised in that: The sealing purge pipe (31) is located on the upper part of the air distribution plate (11) and is used for discharging the flue gas in the circulating pipe (21) into the air distribution plate (11).

4. A coal-fired boiler according to claim 2, characterized in that: The rotation axis of the damper (32) is arranged on the top of the sealing purge pipe (31) and makes the damper (32) always keep an inclined or vertical state, and a smooth layer is arranged on the side of the damper (32) away from the circulating pipe (21), which facilitates the bed material on the damper (32) to fall back into the furnace (1).

5. A coal-fired boiler according to claim 2, characterized in that: A second limiting block (4) is arranged on the sealing purge pipe (31) and is used for limiting the side of the damper (32) away from the first limiting block (33), and the second limiting block (4) is used for preventing the damper (32) from rotating too much.

6. A coal-fired boiler according to claim 1, characterized in that: A feeding assembly (5) is arranged on the side wall of the furnace (1), and the feeding assembly (5) comprises: A coal pre-feeder system (51) is used for providing coal; A coal feeding port (52) is arranged on the side wall of the furnace (1) and is used for discharging the coal provided by the coal pre-feeder system (51) into the furnace (1); A solid waste pre-feeder system (53) is used for providing solid waste fuel; A solid waste feeding port (54) is arranged on the side wall of the furnace (1) and is used for discharging the solid waste provided by the solid waste pre-feeder system (53) into the furnace (1).

7. A coal-fired boiler according to claim 6, characterised in that: The solid waste pre-furnace feeding system (53) is provided with a deodorization assembly (6) for discharging the gas generated in the solid waste pre-furnace feeding system (53) into the furnace chamber (1), and the deodorization assembly (6) comprises: a deodorization pipe (61) arranged on the solid waste pre-furnace feeding system (53) and communicating with the inside of the furnace chamber (1); a deodorization fan (62) arranged on the deodorization pipe (61) and used for discharging the gas in the solid waste pre-furnace feeding system (53) into the furnace chamber (1); a one-way valve (63) arranged on the deodorization pipe (61) and only allowing the deodorization pipe (61) to discharge the gas in the solid waste pre-furnace feeding system (53) into the furnace chamber (1).

8. A coal-fired boiler according to claim 1, characterized in that: The furnace chamber (1) is provided with a high-temperature screen superheater, and the heating surface tube of the high-temperature screen superheater is made of TP347 stainless steel.

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