CN212057228U

CN212057228U - Gas and powder fuel dual-purpose boiler with front-section O-shaped horizontal and rear-section vertical hearths

Info

Publication number: CN212057228U
Application number: CN202020526475.5U
Authority: CN
Inventors: 黄成梠; 罗楠洋; 郭国海; 张榕杰; 张永恒
Original assignee: Fujian Eternal Energy Management Co ltd
Current assignee: Fujian Eternal Energy Management Co ltd
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2020-12-01
Anticipated expiration: 2030-04-10

Abstract

The utility model provides a gas and powder fuel dual-purpose boiler of a front segment O-shaped horizontal type and rear segment vertical type furnace chamber, which can reduce the ash accumulation on the heating surface, solve the coking in the furnace chamber and improve the fuel burnout rate, and comprises a boiler body, wherein the boiler body comprises a boiler barrel, a steam-water system, a burner, a furnace chamber and a flue, the boiler body is provided with a feed inlet, an ash falling port, a burnout air port and a flue gas outlet, a front horizontal type furnace chamber of a combustion area and a rear vertical type furnace chamber provided with the burnout area are arranged in the furnace chamber, the right end of the front horizontal type furnace chamber is communicated with the lower end of the rear vertical type furnace chamber, the burnout air port is arranged on the furnace wall of the rear vertical type furnace chamber and is communicated with the furnace chamber, the boiler barrel is arranged above the rear vertical type furnace chamber, the feed inlet is positioned on the left side of the front horizontal type, the gas inlet end of the flue is communicated with the rear vertical hearth, and the flue gas outlet is arranged at the gas outlet end of the flue.

Description

Gas and powder fuel dual-purpose boiler with front-section O-shaped horizontal and rear-section vertical hearths

Technical Field

The utility model relates to a boiler technical field, horizontal and the vertical furnace's of back end gas of anterior segment O type, dual-purpose boiler of powder fuel very much.

Background

The small and medium-sized industrial pulverized coal boiler is one of the most main coal equipment except the electric station boiler in China, compared with a chain boiler, the industrial pulverized coal boiler adopts a chamber combustion mode, ground pulverized coal particles are carried by air to enter a hearth for combustion, and the boiler has higher boiler thermal efficiency; however, the existing industrial pulverized coal boiler combustion device and technology are still not perfect enough, and the problems that the hearth is easy to coke, the content of fly ash combustible materials is high and the like exist.

SUMMERY OF THE UTILITY MODEL

Therefore, to the above-mentioned problem, the utility model provides a can reduce the heating surface deposition, coke in the solution furnace, improve horizontal and the vertical furnace's of back end gas of anterior segment O type, the dual-purpose boiler of powder fuel of fuel burn-off rate.

In order to realize the technical problem, the utility model adopts the solution that the dual-purpose boiler of gas and powder fuel of a front section O-shaped horizontal type and a rear section vertical type furnace chamber comprises a boiler body, the boiler body comprises a boiler barrel, a steam-water system, combustion equipment, a furnace chamber and a flue, the boiler body is provided with at least one feed inlet, a plurality of ash falling ports, a plurality of burnout air ports and a flue gas outlet, the boiler body is positioned in at least one feed inlet and is internally provided with the combustion equipment with the number corresponding to the number of the feed inlets one by one, the furnace chamber comprises a combustion area and a burnout area, the furnace chamber comprises a front horizontal type furnace chamber and a rear section vertical type furnace chamber, the right end of the front horizontal type furnace chamber is communicated with the lower end of the rear section vertical type furnace chamber, the combustion area is positioned in the front horizontal type furnace chamber, the burnout air port is arranged in the rear section vertical type furnace chamber, the boiler barrel is arranged above the rear vertical type hearth, the at least one feed inlet is located on the left side of the front horizontal type hearth, the combustion equipment comprises a gas-powder dual-purpose combustor, the combustor is obliquely arranged in the feed inlet, a plurality of ash falling ports are arranged at the lower end of the boiler body, the boiler body is provided with a gas locking device at the discharge end of the ash falling port, the flue is vertically arranged on the right side of the boiler body, the gas inlet end of the flue is communicated with the rear vertical type hearth, and a flue gas outlet is formed in the gas outlet end of the flue.

The further improvement is that: the steam-water system comprises a water wall tube, a convection tube bundle, a down tube, a lower header and an upper header, wherein the water wall tube is used for covering the hearth and is arranged outside the hearth, the upper header is arranged above the rear vertical hearth, the lower header is arranged below the front horizontal hearth and the rear vertical hearth, the convection tube bundle is positioned in the flue and is close to the rear vertical hearth, the convection tube bundle is communicated with the upper header and the lower header, and the down tube is communicated with the boiler barrel and the lower header.

The further improvement is that: the flue comprises a front flue and a rear flue, the convection bank is arranged in the front flue, an economizer and an air preheater are arranged in the rear flue, the air preheater is arranged behind the economizer, and the flue gas outlet is arranged behind the air preheater.

The further improvement is that: an outlet header is further arranged above the boiler body, a superheater is arranged above the burnout area in the rear vertical furnace, and the superheater is communicated with the outlet header.

The further improvement is that: and a scraper ash discharging machine is arranged below the discharge end of the ash falling port.

The further improvement is that: and a cleaning mechanism for preventing the ash falling openings from being blocked is arranged at the feed end of the boiler body, which is positioned at the ash falling openings.

The further improvement is that: the cleaning mechanism comprises a plurality of cleaning brushes for cleaning accumulated ash on the ash falling port, a transmission device for driving the cleaning brushes to rotate, a driving device for providing power for the transmission device to rotate and a fixing frame for fixing the transmission device, the fixing frame is detachably arranged on the boiler body, the transmission device is rotatably arranged on the fixing frame, the cleaning brushes are arranged at the feeding ends of the ash falling ports in a one-to-one correspondence mode, and the transmission device can drive the cleaning brushes to rotate radially at the feeding ends of the ash falling ports.

The further improvement is that: the front horizontal hearth is an O-shaped hearth.

The further improvement is that: the combustor is a low-nitrogen powder dual-purpose combustor.

The further improvement is that: the air locking device comprises an air locking ash discharger, the air locking ash discharger comprises a shell, an ash discharging pipe and an ash inlet pipe, the upper end of the ash inlet pipe is connected with the discharge end of an ash falling port, the lower end of the ash inlet pipe is fixedly arranged on the shell, the upper end of the ash discharging pipe is detachably connected below the shell, an air locking cavity is formed in the shell, the ash inlet pipe, the ash discharging pipe and the air locking cavity are communicated, an air locking baffle, a connecting rod and a balance block are arranged in the air locking cavity, one end of the air locking baffle is rotatably arranged on the shell through a bearing, a limiting block is arranged at the joint of the air locking cavity and the ash inlet pipe on the shell, the free end of the air locking baffle can abut against the lower part of the limiting block, one end of the connecting rod is fixedly connected to one side, far away from the air locking baffle, of the balance block is detachably arranged at the free end of.

By adopting the technical scheme, the beneficial effects of the utility model are that: the utility model discloses in set up the combustor in the forefront of boiler body, the combustion area in the furnace is in the forefront promptly in the horizontal furnace of anterior O type, reduces fuel ash and divides back end convection heating surface and afterbody heating surface, reduces the heating surface deposition, improves fuel burn-out rate and heat transfer, has solved convection heating surface deposition, has gone out the difficult scheduling problem of ash, improves boiler efficiency.

Further, utilize the principle that gas is heated and rises, effectively combine anterior O type horizontal furnace and the vertical furnace in rear portion, the fuel that does not burn to the greatest extent in the horizontal furnace of anterior O type can follow the flue gas and turn to vertical furnace and further burn, ensures the abundant burning of fuel, improves fuel utilization ratio, and the horizontal furnace of anterior O type makes with the vertical furnace's in rear portion setting simultaneously the utility model discloses combustible coal powder, living beings powder and three kinds of fuels of natural gas, the commonality is strong.

Furthermore, the heat exchanger is arranged at the upper end part of the rear vertical hearth, the flue space is effectively utilized, and the economizer and the air preheater are arranged in the flue, so that the exhaust gas temperature can be greatly reduced, the exhaust gas heat loss is reduced, and the high efficiency and the energy conservation are realized.

Further, the utility model discloses ash falling port has been set up in the combustion area below for fuel can directly fall naturally after the combustion area burns into the ash, can not pile up the heat transfer that influences heating surface and flue gas in furnace, has improved the burn-out rate, more has economic nature.

Further, the utility model discloses a main combustion area is anterior, and the use is the horizontal furnace of O type, the effectual height that reduces the boiler, and the consumptive material when having saved the boiler and making has reduced construction cost, has economic nature more.

Further, the utility model discloses can arrange one or more combustors according to boiler capacity for this market utility model uses more in a flexible way, and the commonality is high.

Further, the utility model discloses be provided with clearance mechanism at the feed end of ash falling port, can carry out the clearance at 360 no dead angles to the feed end of ash falling port, can effectively clear away the deposition of ash falling port feed end, prevent that ash falling port deposition from hardening to arouse the jam.

Drawings

FIG. 1 is a schematic structural view of a gas and powder fuel dual-purpose boiler with a front section O-shaped horizontal type and a rear section vertical type furnace chamber.

FIG. 2 is a side view of the gas and powder fuel dual-purpose boiler with front section O-shaped horizontal and rear section vertical hearths of the utility model.

Fig. 3 is a schematic view of a partial structure of a cleaning structure in an embodiment of the present invention.

Fig. 4 is a schematic structural diagram of an air-lock ash ejector in an embodiment of the present invention.

Detailed Description

The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 to 4, disclosed in the embodiment of the present invention is a gas and powder fuel dual-purpose boiler with a front-section O-shaped horizontal and rear-section vertical furnace, comprising a boiler body 1, wherein the boiler body 1 comprises a boiler barrel 2, a steam-water system, a low-nitrogen dual-purpose burner 9 (combustible pulverized coal, biomass powder and natural gas), a furnace 10 formed by combining a convection heating surface and a radiation heating surface, and a flue, the boiler body 1 is provided with a feed inlet 5, four ash discharge ports 6, four burned-out air ports 7 and a flue gas outlet 8, the low-nitrogen dual-purpose burner 9 (combustible pulverized coal, biomass powder and natural gas) is fixedly installed in the feed inlet 5, the burner 9 is arranged with the feed end inclined at the upper and lower discharge ends, the steam-water system comprises a water wall pipe 24, a convection pipe bundle 25, a down pipe 26, an upper header 3 and a lower header 4, the water wall tube 24 wraps the hearth 10 and covers the hearth 10, the down pipe 26 is arranged outside the hearth 10, the down pipe 26 has a water inlet end and a water outlet end, the water wall tube 24 has a water inlet end and a water outlet end, the water inlet end of the down pipe 26 is connected with the boiler barrel 2, the boiler barrel 2 and the upper header 3 are arranged above the hearth 10, the lower header 4 is arranged below the hearth 10, the water outlet end of the down pipe 26 extends into the hearth 10 and is communicated with the lower header 4, the water inlet end of the water wall tube 24 is communicated with the lower header 4, the water outlet end of the water wall tube 24 is communicated with the upper header 3, the upper header 3 is connected with the boiler barrel 2 through a pipeline, the convection tube bundle 25 is arranged closely attached to the water wall tube 24 on the right side of the rear vertical hearth 15, the lower end of the convection tube bundle 25 is communicated with the lower header 4, the upper end of the convection tube bundle 25 is communicated with the upper header 3, when the boiler is used, because, the water in the boiler barrel 2 naturally descends into the downcomer 26 without being heated, and enters the lower header 4 through the downcomer 26, the lower header 4 supplies water for the water wall tube 24, the water wall tube 24 is close to the hearth 10 and is influenced by heat radiation, the water in the water wall tube 24 is heated to be changed into steam-water mixture, the density of the steam-water mixture is less than that of the water, so the water automatically flows upwards in the water wall tube 24 and enters the upper header 3, and then flows back to the boiler barrel through the upper header 3 to form water circulation, the convection tube bundle 25 consists of a plurality of convection tubes and communicates the upper header 3 and the lower header 4, and the water in the tubes is changed into the steam-water mixture and flows upwards into the upper header 3 due to the close to the hearth 10 and is heated; the furnace 10 comprises a combustion area 12 and an burnout area 13, the furnace 10 comprises a front O-shaped horizontal furnace 14 and a rear vertical furnace 15, the right end of the front O-shaped horizontal furnace 14 is communicated with the lower end of the rear vertical furnace 15 to form an L shape, the combustion area 12 is positioned in the front O-shaped horizontal furnace 14, the burnout area 13 is positioned in the middle section of the vertical furnace 10, four burnout air ports 7 provide burnout air for the burnout area 13, the four burnout air ports 7 are all arranged on the furnace wall of the rear vertical furnace 15 and can be communicated with the furnace 10 at the lower end of the burnout area 13, a feed port 5 is arranged on the left side of the front O-shaped horizontal furnace 14 on the boiler body 1, the output end of a low-nitrogen dual-purpose burner 9 is aligned with the combustion area 12, the four ash falling ports 6 are all arranged on the lower end of the boiler body 1 and are positioned below a lower header 4, and the feed ports on the boiler body 1 positioned at the four ash falling ports 6 are provided with cleaning for preventing the ash falling ports The mechanism comprises four cleaning brushes 28 for cleaning cokes on the ash falling port 6, a worm 29, four worm wheels 30 meshed with the worm 29, a driving motor 31 and a fixing frame 32 for fixing the worm wheels and the worm, wherein the fixing frame 32 is transversely arranged in the boiler body 1 and is positioned above the feeding end of the ash falling port 6, two ends of the fixing frame 32 are detachably arranged on the boiler body 1 through bolts, a worm channel is arranged on the fixing frame 32, the worm 29 is arranged in the worm channel in a penetrating manner, the left end of the worm 29 penetrates out of the worm channel and is fixedly connected with a rotating shaft of the boiler body 1 and the driving motor 31 through a coupler, a shell of the driving motor 31 is fixedly arranged on the outer wall of the boiler body 1, four openings are arranged on the worm channel corresponding to the positions of the four ash falling ports 6, the four worm wheels 30 are arranged on the fixing frame 32 and are respectively meshed with the worm 29 in the worm channel through the four openings, the cleaning brush 28 comprises a brush holder 34 and a scraper 33, the scraper 33 is fixedly arranged at two sides of the lower end of the brush holder 34 and is in a straight shape, the upper end of the brush holder 34 is locked on a worm wheel 30 through a screw, the lower end of the brush holder 34 extends into the feeding end of the dust falling port 6, the scraper 33 at two sides is tangent to the inner wall of the dust falling port 6, the driving motor 31 drives the worm 29 to rotate when rotating, the worm 29 rotates the four worm wheels 30, and accordingly the four cleaning brushes 28 fixed on the worm wheels 30 rotate along with the worm wheels 30 in the radial direction, and the scraper 33 is tangent to the inner wall of the dust falling port 6, so that the scraper 33 can clean the feeding end of the dust falling port 6 in a 360-degree blind angle-free manner when the cleaning brush 28 rotates in the radial direction, thereby well scraping off the dust on the feeding end of the dust falling port 6, effectively preventing the dust falling port from blocking caused by dust accumulation and hardening, and because the scraper 33, The dust-locking type dust-removing device is in a straight line shape, when the driving motor 31 does not work, the scraper 33 does not block the dust falling port 6, the falling dust can still smoothly pass through the dust falling port 6 from the cleaning brush 28, the air-locking dust remover 16 is installed on the discharge ends of four dust falling ports 6, the air-locking dust remover comprises a shell 44, a dust outlet pipe 35 and a dust inlet pipe 36, the upper end of the dust inlet pipe 36 is connected with the discharge end of the dust falling port 6 through a flange, the lower end of the dust inlet pipe 36 is welded on one side of the upper end of the shell 44, the upper end of the dust outlet pipe 35 is connected below the shell 44 through a quick connector, an air-locking cavity 37 is formed in the shell 44, the dust inlet pipe 36 and the dust outlet pipe 35 are communicated with the air-locking cavity 37, an inclined plate 38 inclined towards the air-locking cavity 37 is arranged on one side of the lower end of the dust inlet pipe 36 far away from the air-locking cavity 37, the falling dust falls down to the inclined plate 38 and slides along the inclined direction of the inclined, The connecting rod 40 and the balance block 41, one end of the air-locking baffle 39 is rotatably arranged on the shell 44 through a bearing 43, a limit block 42 is arranged on the shell 44 at the joint of the air-locking chamber 37 and the inclined plate 38 at the lower end of the ash inlet pipe 36 in a protruding manner towards the air-locking chamber 37, the free end of the air-locking baffle 39 can abut against the lower part of the limit block 42, one end of the connecting rod 40 is fixedly connected to one side of the bearing 43 far away from the air-locking baffle 39, the free end of the connecting rod 40 is in threaded connection with the balance block 41, because the weight of the balance block 41 and the connecting rod 40 is greater than the natural weight of the air-locking baffle 39, the balance block 41 can give a downward force to the free end of the connecting rod 40 in a natural state, one end of the connecting rod 40 drives the bearing 43 to rotate, the bearing 43 drives the air-locking baffle 39 to lift up, when the free end of the air-locking baffle 39 abuts against the limit block 42, the, the gas coming from the ash discharge pipe 35 is separated and can not reversely enter the boiler through the ash inlet pipe 36, so as to achieve air locking, when the falling ash is accumulated on the air locking baffle 39 and the weight of the baffle side of the bearing 43 exceeds the weight of the side of the connecting rod 40, the air locking baffle 39 is pushed away by the falling ash, the ash inlet pipe 36 is communicated with the air locking cavity 37, the falling ash is rapidly and naturally dropped through the air locking cavity 37 by gravity and then is discharged from the ash discharge pipe 35, the air locking baffle 39 is restored to the natural state after the falling ash is discharged, the ash inlet pipe 36 is sealed, the scraper ash discharging machine 17 is arranged below the discharge end of the ash discharge port 6 (the scraper ash discharging machine mentioned in the utility model is a known product and can be directly applied to the utility model, the structure, installation and working mode of the scraper ash discharging machine are known and are not described in detail herein), the flue is vertically arranged on the right side of the boiler body 1, the flue comprises a front flue 27 and a rear flue 11, the front flue 27 and the rear flue 11 are both provided with an air inlet end and an air outlet end, the periphery of the front flue 27 is covered by a water wall tube 24, the air inlet end of the front flue 27 is at the upper part and the air outlet end is at the lower part, the air inlet end of the rear flue 11 is at the lower part and the air outlet end is at the upper part, the air inlet end of the front flue 27 is communicated with the upper end of the rear vertical furnace 15, the air inlet end of the rear flue 11 is communicated with the air outlet end of the front flue 27, a convection tube bundle 25 is arranged in the front flue 27, and an economizer 18 (the economizer mentioned in the utility model is a known product, can be purchased in the market and directly applied to the utility model, the structure and the installation and the working mode are known contents and are not described herein) and the air preheater 19 (the air preheater mentioned in the utility model is a known product, can be purchased in the market and directly applied to the utility model, the structure, installation and working mode of the coal economizer are known and are not described herein) an inlet and an outlet, wherein the inlet is externally connected with a blower through a pipeline, the outlet is connected with the low-nitrogen powder dual-purpose burner 9 through a pipeline, flue gas in a rear flue 11 is used for preheating air to be fed into the low-nitrogen powder dual-purpose burner 9 and providing secondary air for the low-nitrogen powder dual-purpose burner 9, so that the heat exchange performance of the boiler is improved, the energy consumption is reduced, a water inlet 20 is arranged at the upper end of the coal economizer 18, a water outlet 21 is arranged at the lower end of the coal economizer, the water outlet 21 is connected with the boiler barrel 2 through a pipeline, water is fed into the coal economizer 18 from the water inlet 20, the coal economizer 18 can absorb the heat of the flue gas in the rear flue 11 to heat the water, the heated water flows into the boiler barrel 2 from the water outlet 21 through the pipeline, the coal economizer 18 utilizes the waste heat, the energy is saved, the efficiency is improved, the superheater is arranged above the burnout zone 13 in the rear vertical furnace 15, the superheater comprises a serpentine superheater tube 22 and an outlet header 23, the serpentine superheater tube 22 is arranged at the upper part in the rear vertical furnace 15, the outlet header 23 is arranged outside the rear vertical furnace 15, the serpentine superheater tube 22 has a steam inlet end and a steam outlet end, the steam inlet end is communicated with the boiler barrel 2, the steam outlet end is communicated with the outlet header 23, steam in the boiler barrel 2 enters the serpentine superheater tube 22 from the steam inlet end of the serpentine superheater tube 22, and is subjected to transverse and longitudinal scouring of flue gas in the rear vertical furnace 15 in the serpentine superheater tube 22, and the steam is gradually heated in the serpentine superheater tube 22 to become superheated steam, and then flows into the outlet header 23 from the steam outlet end.

The working principle is as follows:

the low-nitrogen powder dual-purpose combustor 9 sprays fuel to a combustion area 12 located in a front O horizontal type hearth 10 at an inclined downward angle, the fuel is combusted in the combustion area 12, burnt-out furnace ash freely falls down and is discharged through an ash discharge port, the fuel which is not burnt out is transferred to a vertical hearth 10 along with a smoke belt to be further combusted, combustion-supporting air is arranged around a rear vertical hearth 15 and enters a burning-out area 13 through four burning-out air ports 7 to provide oxygen for the fuel to be completely combusted, the furnace ash falls down and is discharged through an ash discharge port 6 below after the fuel is burnt out, the furnace ash falls into a scraper ash discharging machine 17 after being discharged from the ash discharge port 6, the ash is discharged through the scraper ash discharging machine 17, and an air locking ash discharger 16 is arranged at the discharge end of the ash discharge port 6 to reduce the air leakage of the boiler in the ash discharging process.

Having shown and described the basic principles and essential features of the invention and its advantages, it will be understood by those skilled in the art that the present invention is not limited by the embodiments described above, which are merely illustrative of the principles of the invention, but is susceptible to various changes and modifications without departing from the spirit and scope of the invention, all of which are intended to be covered by the appended claims and their equivalents.

Claims

1. Horizontal and vertical furnace's of back end gas of anterior segment O type, dual-purpose boiler of powder fuel, including the boiler body, the boiler body includes a drum, steam-water system, combustion apparatus, furnace, flue, at least one feed inlet, a plurality of ash falling hole, a plurality of after-fire wind gap, exhanst gas outlet have been seted up on the boiler body, it is provided with the combustion apparatus with feed inlet number one-to-one to lie in at least one feed inlet on the boiler body, including combustion area and after-fire district, its characterized in that in the furnace: the hearth comprises a front horizontal hearth and a rear vertical hearth, the right end of the front horizontal hearth is communicated with the lower end of the rear vertical hearth, the combustion zone is positioned in the front horizontal hearth, the burnout zone is positioned in the rear vertical hearth, the burnout air port is arranged on the furnace wall of the rear vertical hearth and positioned at the lower end of the burnout zone and can be communicated with the hearth, the boiler barrel is arranged above the rear vertical hearth, the at least one feed inlet is positioned on the left side of the front horizontal hearth, the combustion equipment comprises a gas-powder dual-purpose burner, the burner is obliquely arranged in the feed inlet, the ash falling ports are all arranged at the lower end part of the boiler body, the discharge end of the ash falling port on the boiler body is provided with a gas locking device, the flue is vertically arranged on the right side of the boiler body, and the gas inlet end of the flue is communicated with the rear vertical hearth, the flue gas outlet is arranged at the gas outlet end of the flue.

2. The gas and powder fuel dual-purpose boiler with the front-section O-shaped horizontal and the rear-section vertical hearth according to claim 1, characterized in that: the steam-water system comprises a water wall tube, a convection tube bundle, a down tube, a lower header and an upper header, wherein the water wall tube is used for covering the hearth and is arranged outside the hearth, the upper header is arranged above the rear vertical hearth, the lower header is arranged below the front horizontal hearth and the rear vertical hearth, the convection tube bundle is positioned in the flue and is close to the rear vertical hearth, the convection tube bundle is communicated with the upper header and the lower header, and the down tube is communicated with the boiler barrel and the lower header.

3. The gas and powder fuel dual-purpose boiler with the front-section O-shaped horizontal and the rear-section vertical hearth according to claim 2, characterized in that: the flue comprises a front flue and a rear flue, the convection bank is arranged in the front flue, an economizer and an air preheater are arranged in the rear flue, the air preheater is arranged behind the economizer, and the flue gas outlet is arranged behind the air preheater.

4. The gas and powder fuel dual-purpose boiler with the front-section O-shaped horizontal and the rear-section vertical hearth according to claim 1, characterized in that: an outlet header is further arranged above the boiler body, a superheater is arranged above the burnout area in the rear vertical furnace, and the superheater is communicated with the outlet header.

5. The gas and powder fuel dual-purpose boiler with the front-section O-shaped horizontal and the rear-section vertical hearth according to claim 1, characterized in that: and a scraper ash discharging machine is arranged below the discharge end of the ash falling port.

6. The dual-purpose boiler of gas and powder fuel with front-segment O-shaped horizontal and rear-segment vertical hearths as claimed in claim 5, wherein: and a cleaning mechanism for preventing the ash falling openings from being blocked is arranged at the feed end of the boiler body, which is positioned at the ash falling openings.

7. The dual-purpose boiler of gas and powder fuel with front-segment O-shaped horizontal and rear-segment vertical hearths as claimed in claim 6, wherein: the cleaning mechanism comprises a plurality of cleaning brushes for cleaning accumulated ash on the ash falling port, a transmission device for driving the cleaning brushes to rotate, a driving device for providing power for the transmission device to rotate and a fixing frame for fixing the transmission device, the fixing frame is detachably arranged on the boiler body, the transmission device is rotatably arranged on the fixing frame, the cleaning brushes are arranged at the feeding ends of the ash falling ports in a one-to-one correspondence mode, and the transmission device can drive the cleaning brushes to rotate radially at the feeding ends of the ash falling ports.

8. The gas and powder fuel dual-purpose boiler with the front-section O-shaped horizontal and the rear-section vertical hearth according to claim 1, characterized in that: the front horizontal hearth is an O-shaped hearth.

9. The gas and powder fuel dual-purpose boiler with the front-section O-shaped horizontal and the rear-section vertical hearth according to claim 1, characterized in that: the combustor is a low-nitrogen powder dual-purpose combustor.

10. The gas and powder fuel dual-purpose boiler with the front-section O-shaped horizontal and the rear-section vertical hearth according to claim 1, characterized in that: the air locking device comprises an air locking ash discharger, the air locking ash discharger comprises a shell, an ash discharging pipe and an ash inlet pipe, the upper end of the ash inlet pipe is connected with the discharge end of an ash falling port, the lower end of the ash inlet pipe is fixedly arranged on the shell, the upper end of the ash discharging pipe is detachably connected below the shell, an air locking cavity is formed in the shell, the ash inlet pipe, the ash discharging pipe and the air locking cavity are communicated, an air locking baffle, a connecting rod and a balance block are arranged in the air locking cavity, one end of the air locking baffle is rotatably arranged on the shell through a bearing, a limiting block is arranged at the joint of the air locking cavity and the ash inlet pipe on the shell, the free end of the air locking baffle can abut against the lower part of the limiting block, one end of the connecting rod is fixedly connected to one side, far away from the air locking baffle, of the balance block is detachably arranged at the free end of.