CN114413255A

CN114413255A - Fluidized bed boiler with water-cooling gas-solid separator and four-and seven-return water-cooling flues

Info

Publication number: CN114413255A
Application number: CN202210081387.2A
Authority: CN
Inventors: 王森
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-01-26
Filing date: 2022-01-24
Publication date: 2022-04-29
Also published as: CN112856396A

Abstract

The invention discloses a fluidized bed boiler with a water-cooling gas-solid separator and four and seven return water-cooling flues, which comprises a steam boiler, a forced circulation pipe frame type hot water boiler, a power station boiler and an ultra-large power station boiler, wherein the fluidized bed boiler comprises a hearth main combustion chamber, an auxiliary combustion chamber, a burnout chamber, a four return water-cooling flue, a seven return water-cooling flue and a water-cooling ceiling; the separator of the invention does not need any special device and separating element, thus saving the refractory heat-insulating material and steel frame support of all cyclone separators; the integrated structure can save the fireproof heat-insulating materials of the two transverse walls; the CFB boiler with the four-return-flue gas more than 75T and the CFB boiler with the seven-return-flue gas more than 600MW can respectively reduce the height of the boiler body by 30 percent and 40 percent, and respectively save 40 percent, 30 percent, 50 percent and 40 percent of the refractory heat-insulating material and the steel frame of the whole boiler; the ultra-low initial smoke emission and the wet structure of the furnace wall flue of the whole heating surface of the furnace body can eliminate the abrasion of the convection heating surface, greatly save the maintenance cost and prolong the service life of the boiler.

Description

Fluidized bed boiler with water-cooling gas-solid separator and four-and seven-return water-cooling flues

Technical Field

The invention discloses a fluidized bed boiler with a water-cooling gas-solid separator and four and seven return water-cooling flues, and relates to a circulating fluidized bed hot water boiler, a circulating fluidized bed steam boiler, a circulating fluidized bed cogeneration boiler and a circulating fluidized bed power station boiler; in particular to an ultra-large circulating fluidized bed power station boiler and an ultra-large circulating fluidized bed central heating boiler; relates to the energy-saving and emission-reducing transformation of various circulating fluidized bed boilers, pulverized coal boilers and grate firing chain boilers in use; to the upgrading of various circulating fluidized bed boilers in use; relates to a low-cost clean and efficient low-rank coal boiler, a grate firing chain boiler and a natural gas boiler.

Background

The circulating fluidized bed boiler has the characteristics of easy regulation of the mixing ratio of air and fuel and low-temperature circulating combustion in graded air supply, can burn all coal types, particularly low-rank coal, has high combustion efficiency, can realize high-efficiency removal of sulfur dioxide and original ultralow generation of nitrogen oxide in the circulating fluidized bed boiler at low cost, ensures that the pollutant emission of the circulating fluidized bed boiler can be comparable with that of a natural gas boiler, and ensures that the pollutant emission of the circulating fluidized bed boiler is lower than that of the natural gas boiler when power generation and heat supply are carried out. Circulating fluidized bed boilers have become a mature technology for clean and efficient utilization of coal at present.

However, the current fact is that circulating fluidized bed boilers have absolute advantages in market competition only when using low-grade coal and having special requirements on environmental protection; when the market is not limited by coal types and has no special requirements on environmental protection, the circulating fluidized bed boiler is in absolute disadvantage of market competition; this is caused by the ultra-high structure of the furnace body of the circulating fluidized bed boiler, the high energy consumption of raw materials of a core component 'cyclone separator', the high manufacturing and installation cost, the high failure rate, the high maintenance and repair cost, the easy abrasion of the convection heating surface and other pain points. If the technology has a great breakthrough and can be popularized in a large scale in the market, the technology has important strategic significance on energy conservation, consumption reduction, emission reduction and climate change response in China and even the world.

The fluidized bed boiler with the highest occupation rate and the most mature in the current Chinese market is a high-temperature heat-insulation cyclone fluidized bed boiler made of wear-resistant heat-insulation materials. The most popular fluidized bed boiler in the European and American markets at present is a circular steam (water) cooling cyclone fluidized bed boiler, and the common defects of the two boiler types are as follows: the framework furnace wall and the steam-water system of the boiler body are formed by mutually communicating three independent bodies, namely a hearth, a cyclone separator and a shaft flue, the consumption of the refractory heat-insulating material and a steel frame of the boiler body is large due to the fact that the independent wall surfaces are multiple and the boiler body is high, in addition, the structural forms of the boilers are the same, and only the sizes of the boiler types are different, so that the cost of the medium-sized boiler and the cost of the small-sized boiler are high, and particularly the cost of the small-sized boiler is ultrahigh.

The high-temperature heat-insulation cyclone separator is firstly seen, and the thickness of the wear-resistant heat-insulation material used by the separator is larger than 300mm, so that the raw material consumption of the separator is large, the manufacturing and installation cost is high, the defects of large thermal inertia and heat loss, high possibility of high-temperature coking of the separator, slow start and stop of a boiler, high failure rate, high maintenance and repair cost, easy abrasion of a convection heating surface and the like exist. The separator with the structure is composed of a steel shell, a heat insulation block, heat insulation refractory bricks, an anti-abrasion liner and a plurality of layers of fastening bricks, and has high requirements on construction process and refractory material selection.

Referring to the circular steam (water) cooling cyclone separator, although the separator reduces wear-resistant heat-insulating materials, overcomes the defects of large thermal inertia and heat loss, ensures that a boiler is not coked and is started and stopped quickly, the defects of high wind speed, large resistance, serious flying ash lifting entrainment, high power consumption of a draught fan, high initial emission concentration of smoke dust, easy abrasion of a convection heating surface and the like exist, particularly the structure of a membrane wall and a circular ring header of the separator is complex, the process requirement and the manufacturing cost are extremely high and the price is high, and once the wear-resistant castable falls off from the surface of a cyclone cylinder, a steam-water pipeline is quickly abraded to cause leakage.

In addition, a square water (steam) cooling cyclone separator fluidized bed boiler is provided, a separator membrane type water-cooled wall and a combustion chamber membrane type water-cooled wall are integrated, although the boiler structure is very compact; the fire-resistant and wear-resistant lining is thin, and the start and stop of the boiler are fast; the advantage of small heat dissipation losses, however, the separation efficiency and stability are significantly lower than that of round water

The (steam) cold cyclone separator has the characteristic of centrifugal force separation which is not matched with a square structure, so that the separation efficiency of the square water (steam) cold cyclone separator fluidized bed boiler is low normally; the efficiency and stability of gas-solid separation are directly related to the performance of the fluidized bed boiler, obviously, the boiler type has no market competitive advantage; therefore, although the square water (steam) cold cyclone fluidized bed boiler is reported as the third generation fluidized bed boiler, the square water (steam) cold cyclone fluidized bed boiler does not talk to market share even though the publicity has been in the past for many years.

Although the inertial gravity separator of the circulating fluidized bed boiler disclosed in the invention patent No. ZL201480002881.9 has many outstanding advantages compared with the above two kinds of cyclone separators, such as low flow resistance, power consumption of induced draft fan, water-cooled separator structure, wear-resistant high-temperature material saving, low emission of raw smoke, etc., there are significant drawbacks in the key technologies of high-temperature and gravity separation, such as the first key technology of the patent, whether the "one-stage 'high-temperature' inertial gravity water-cooled separator" described in the claims can achieve "high temperature" is difficult to guarantee; the second key technology of the patent is that according to the vertical structure form of the water cooling wall of the guide gas-solid two-phase direct-flushing storage bin in the scheme 6 in the attached drawing of the specification, the low flow resistance of the descending flue is not optimal; the third key technology of the patent seriously influences the gravity settling efficiency of the smoke dust and the ultralow emission of the original smoke dust according to the structural form of the water-cooled wall of the guide gas-solid two-phase direct flushing storage bin in the scheme 7 in the attached figure of the specification; many designs complicate and cost-prohibitive manufacturing and installation processes.

Disclosure of Invention

Based on the above, the invention provides the fluidized bed boiler with the water-cooling gas-solid separator and the four-and seven-return water-cooling flues, which not only solves the market competition short plate of the traditional cyclone separator and the ultrahigh short plate of the boiler body and solves the invention patent defect of ZL201480002881.9, but also comprehensively innovates in the new structure, the new process and the new high-temperature water-cooling gas-solid separator of the boiler body, so that the advantages of the invention are more prominent and have no substitution.

The upper part of the hearth is provided with the tapered section, so that the abrasion resistance of the heating surface under the conditions of high temperature and increased smoke velocity can be ensured; the two-return high-temperature accelerating descending reducing flue can accelerate high-temperature flue gas to enter the auxiliary combustion chamber with a large expansion space and a turning channel for full combustion.

Secondly, the upper part of the hearth is provided with a reducing section and a two-pass high-temperature accelerating descending reducing flue rear wall which moves forwards, so that the optimal design of different flow directions, different flow paths and different flow velocities of the dust-containing flue gas can be realized, and the performance advantage of gas-solid high-temperature inertial gravity separation is more stable and reliable.

Thirdly, the furnace walls and the flues of all the radiation convection heating surfaces of the boiler body of the invention all realize a water vapor cooling wet type structure, thereby greatly reducing the failure rate and the maintenance cost and prolonging the service life of the boiler.

And fourthly, the naturally enlarged burnout chamber (three-return-stroke upward flue) has the whole course of 3-5 m low flow velocity, so that the burnout degree of combustible substances can be improved, especially the ultralow emission of initial smoke dust is realized, the abrasion of a convection heating surface can be eliminated, and the problem which cannot be solved by a cyclone separator is really solved.

Compared with the traditional CFB boiler with a cyclone separator, the CFB boiler with the four-return water-cooled flue more than 75T can reduce the height of the boiler body by 30 percent, and only the boiler body can save raw materials of the boiler body by 30 percent.

And sixthly, compared with the traditional cyclone separator CFB boiler, the seven-return water-cooled flue of the ultra-large CFB boiler with more than 600MW can reduce the height of the boiler body by 40 percent, and only one can save raw materials of the boiler body by 40 percent.

The fluidized bed boiler with the water-cooling gas-solid separator and the four-return and seven-return water-cooling flues provided by the invention comprises: the device comprises a hearth, a hearth main combustion chamber, a tapered section at the upper part of the hearth, a two-return high-temperature accelerated downward tapered flue, an auxiliary combustion chamber (a large expansion space and a turning channel), a burnout chamber (a three-return upward flue), a four-return water-cooling flue, a seven-return full-steam cold heating surface, a water-cooling ceiling, a superheater and an economizer.

The four-return water-cooling flue comprises a return hearth main combustion chamber to a hearth flue gas outlet, a two-return high-temperature accelerated descending tapered flue, a three-return ascending flue, a boiler tail convection flue and a vertical shaft flue.

The seven-return water-cooling flue comprises a return hearth main combustion chamber to a hearth flue gas outlet, a two-return high-temperature accelerated descending tapered flue in front of the hearth, a two-return high-temperature accelerated descending tapered flue in back of the hearth, a three-return ascending flue in front of the hearth (upper burnout chamber), a three-return ascending flue in back of the hearth (upper burnout chamber), a vertical wet water vapor cooling flue in upper part of the hearth, a convection flue in tail part of the boiler, and the convection flue in tail part of the boiler is a vertical shaft flue.

The seven-return-stroke full-water-vapor cooling heating surface comprises seven cross-wall membrane water-cooled walls of a transverse and lower six return-stroke flue and two laterally symmetrical membrane water-cooled walls which are all water-cooled heating surfaces; the upper end of the longitudinal wet-type water vapor cooling flue at the upper part of the hearth is a water-cooling heated surface, the lower end high-temperature superheater of the longitudinal wet-type water vapor cooling flue at the upper part of the hearth is a steam-cooling heated surface, and the front, rear, left and right side ends of the longitudinal wet-type water vapor cooling flue at the upper part of the hearth are water-cooling heated surfaces.

The novel structure of the invention has the following remarkable beneficial effects:

the four-return water-cooling flue structure of the invention ensures that the flue gas flow of the CFB boiler with the height of more than or equal to 75T is still obviously longer than that of a cyclone separator under the condition of reducing the height of the boiler body by 30 percent, and only the flue gas flow can save 30 percent of wear-resistant heat-insulating materials and 30 percent of steel frames of the whole boiler. The integrated structure of the invention can save the heat insulation materials of the two transverse walls, which account for about 10 percent of the whole machine and about 5 percent of the steel frame; and the whole double faces of the three diaphragm wall type water cooling walls are heated, so that the heat transfer effect can be obviously improved. And the heating surface of the cyclone fluidized bed boiler is heated on one side.

The water-cooling gas-solid separation device does not need any special device and separation original, and the water-cooling high-temperature inertia gravity separator is naturally formed by the heating surface space, so that compared with the traditional fluidized bed boiler matched with a cyclone separator, the water-cooling high-temperature inertia gravity separator can save about 10 percent of wear-resistant heat-insulating materials and about 5 percent of steel frames of the whole machine. Therefore, each boiler of the CFB with the temperature of more than 75T can save about 50 percent of refractory and heat-insulating materials and about 40 percent of steel frames.

The seven-return water-cooling flue structure of the invention ensures that the flue gas flow of the supercritical CFB boiler with the height of more than 600MW is still obviously longer than that of a fluidized bed boiler with a cyclone separator under the condition of reducing the height of the boiler body by 40 percent, and only the flue gas flow can save 40 percent of wear-resistant heat-insulating materials and 40 percent of steel frames of the whole boiler; according to the structural rule of the four-return water-cooling flue: each boiler of the supercritical CFB with the power of more than 600MW can save about 60 percent of fireproof heat-insulating materials, about 50 percent of steel frames, and the whole double surfaces of the five cross wall membrane type water-cooled walls are heated, so that the heat transfer effect can be obviously improved.

The invention relates to a longitudinal wet steam cooling flue at the upper part of a hearth of an ultra-large power station boiler structure, wherein six surfaces of the upper part, the lower part, the front part, the rear part and two sides of the longitudinal wet steam cooling flue at the upper part of the hearth are all wet structures, namely the upper wall of the longitudinal wet steam cooling flue at the upper part of the hearth is a full-film water wall and heat insulation material, the lower wall of the longitudinal wet steam cooling flue at the upper part of the hearth is a high-temperature superheater covering six flues, the high-temperature superheater is sealed (sealing layer) by pouring refractory materials with a film-wall high-temperature superheater or a light tube high-temperature superheater, is abutted against an outlet of an ascending flue (an inlet of the longitudinal wet steam cooling flue at the front top part of the boiler) at the front three return strokes of the hearth and an outlet of an ascending flue (an inlet of the longitudinal wet steam cooling flue at the rear top part of the boiler) at the rear part of the hearth, and is abutted against a light tube high-temperature superheater, a high-temperature superheater and a heat tube, The distance between the light pipe high-temperature overheaters is the outlet of the front three return upward flues of the hearth and the outlet of the rear three return upward flues of the hearth; the high-temperature superheater is closely attached to the top of the vertical shaft flue, and the distance between the high-temperature superheater and the vertical shaft flue is equal to the distance between the high-temperature superheater and the vertical shaft flue; the front wall of the boiler top flue is a hearth front wall film type water-cooled wall and a heat insulation material, and the rear wall of the boiler top flue is a hearth rear wall film type water-cooled wall and a heat insulation material. Not only effectively protects the furnace wall and can prolong the service life of the flue by 5-7 years, but also increases the heating surface and can improve the thermal efficiency of the boiler. And the top flue of the cyclone separator fluidized bed boiler is poured by high-temperature refractory materials, so that the service life is short, and the heat dissipation loss is large.

The furnace upper part reducing section and the two-return high-temperature accelerating downward reducing flue of the invention bring three beneficial effects: the cross section of the whole process of the burnout chamber (three-return-stroke ascending flue) is favorably enlarged, the whole process low flow velocity of the exhaust flue is ensured, the burnout degree of combustible materials is favorably improved, and the entrainment of the air flow to the fly ash is reduced. And secondly, the smoke temperature and the smoke speed can be improved, and the smoke can timely enter an auxiliary combustion chamber with a large expansion space and a turning channel for full combustion and radiation heat transfer. Thirdly, the reducing section of the upper part of the hearth can improve the heat load of the upper part of the hearth, the normal high temperature of the upper part of the hearth can be met by natural secondary air or lower secondary hot air temperature, and the hot air is concentrated to meet the requirements of high temperature and low oxygen (flue gas recirculation) of primary air in a dense-phase region.

The cross sections of the auxiliary combustion chamber (large expansion space and turning channel) and the burnout chamber (three-return-stroke ascending flue) are all larger than the cross section of the hearth, so that full combustion and radiant heat transfer of combustible materials are facilitated, the carbon content of fly ash is reduced, and the heat efficiency is improved.

The fluidized bed boiler with the water-cooling gas-solid separator and the four-and seven-return water-cooling flues also comprises a water outlet, a gas collecting tank, an automatic exhaust valve and an economizer, wherein a four-in-one water-cooling ceiling is longitudinally arranged at the upper ends of a transverse collecting box on the front wall of a hearth, a transverse collecting box on the rear wall of the hearth, a transverse collecting box on the water-cooling wall of a guide smoke direct flushing bin, a transverse collecting box on the front wall of a vertical shaft and a transverse collecting box on the rear wall of the vertical shaft, the front end of the four-in-one water-cooling ceiling is communicated with the front transverse collecting box of the four-in-one water-cooling ceiling, the rear end of the four-in-one water-cooling ceiling is communicated with the rear transverse collecting box of the four-in-one water-cooling ceiling, the water outlet is communicated with the center of the upper part of the rear transverse collecting box of the four-in-one water-cooling ceiling, and exhaust pipes are communicated with the automatic exhaust valve through the four-in-one water-cooling ceiling; the superheater ceiling is longitudinally arranged at the upper ends of a transverse collecting box on the front wall of the hearth, a transverse collecting box on the rear wall of the hearth, a transverse collecting box on the water-cooled wall of a guide flue gas direct-flushing storage bin, a transverse collecting box on the front wall of the shaft and a transverse collecting box on the rear wall of the shaft, the front end of the superheater ceiling is communicated with a steam outlet, the rear end of the superheater ceiling is communicated with a reheater, and an air duct penetrates through the superheater ceiling and is communicated with an air guide main pipe.

The full-film water-cooled wall separator, the full-film water-cooled wall flue and the full-film water (steam) cooling ceiling have good sealing performance, are beneficial to protecting the furnace wall, greatly prolong the service life of the boiler and save the maintenance cost; but also can thoroughly solve the difficulty that the heating surface in the large circulating fluidized bed boiler bed can not be arranged; the defects that the overall arrangement mode of a combustion system, equipment and a boiler of a traditional fluidized bed external bed (external superheater) is complex can be thoroughly solved. The stage that the large circulating fluidized bed power station boiler depends on module superposition or amplification is thoroughly separated, and the larger the boiler is, the larger the saved refractory heat-insulating material and steel frame is.

Ultra-high heat transfer performance: the five cross wall membrane type water-cooled walls of the front wall membrane type water-cooled wall and the rear wall membrane type water-cooled wall of the hearth of the CFB boiler with the seven-return water-cooled flue, the dust-containing smoke direct flushing bin water-cooled wall, the front wall membrane type water-cooled wall of the vertical shaft and the rear wall membrane type water-cooled wall of the vertical shaft are heated on two sides. All of the cross-wall membrane walls of a conventional CFB boiler are heated on all of one side.

The water circulation flow resistance is little, easy access and maintenance, equipment operation safety and stability: all the headers of the membrane water-cooled wall of the separator are straight headers, and both ends of each header are provided with hand holes; the membrane water-cooled wall header of the water-vapor cold cyclone separator is a circular header, so that the water circulation flow resistance is high, and the maintenance is difficult once the scale deposition is serious due to management errors; and once the anti-abrasion castable on the surface of the cyclone cylinder falls off the steam-water pipeline, the steam-water pipeline is quickly abraded to cause leakage.

High-end structural design, furnace body gas tightness is super good, and performance is stable for a long time: the full-membrane type water-cooled wall hearth, the full-membrane type water-cooled wall separator, the full-membrane type water-cooled wall vertical shaft and the full-membrane type water-cooled wall ceiling can all be in a full-membrane type water-cooled wall integrated structure; the service life of the whole boiler can be prolonged. The hearth, the separator and the vertical shaft of the water-vapor-cooled circular cyclone fluidized bed boiler are all independent structures, and the more the number of the cyclones, the more the independent structures are. Some parts are difficult to realize the full-film water-cooled wall, but the pouring of the refractory material is adopted, so that the service life is influenced, the maintenance cost is increased, and the heat loss is increased.

The new process and the remarkable beneficial effects of the invention are as follows: the invention can adopt different design, manufacture and installation processes of the boiler body according to the size of the boiler.

1. The invention relates to a small boiler body; the components are assembled into a component in a factory, so that the manufacturing quality is ensured and the manufacturing efficiency is improved by utilizing the tool, and the whole machine can be assembled on the site in a split manner. The installation method can greatly reduce the field processing and installation amount, and is favorable for ensuring the installation quality and improving the installation efficiency.

2. The invention relates to a boiler body; the single components are processed in a factory and are communicated and assembled on a construction site through communicating pipes. The installation method can greatly reduce the field processing and installation amount and obviously improve the installation quality and the installation efficiency.

3. The invention is a large, large and ultra-large boiler body; the single components are processed in a piece mode in a factory, the single components are butt-welded and additionally welded to seal flat iron in a piece mode on a construction site, and the single components are communicated with the communicating pipe, the air guide pipe and the down pipe respectively. The field processing and installation amount is greatly reduced, and the installation quality is ensured and the installation efficiency is improved.

4. The structure is simple, the process is advanced: enterprises with 100% A-grade qualification of the full-mode wall high-end product can produce the full-mode wall high-end product, and most of enterprises with B-grade qualification can produce the full-mode wall high-end product, so that the manufacturing and installation cost is greatly saved. However, Chinese enterprises with 90% A-level qualification of the water-vapor cold circular cyclone separator have no capacity for production, only a few enterprises with A-level qualification can produce at present, the process is extremely complex, and the manufacturing and installation cost is extremely high; although the high-temperature water vapor cooling circular cyclone separator fluidized bed boiler has many advantages over the high-temperature adiabatic cyclone separator fluidized bed boiler, the market share in China is very low due to high manufacturing cost and high selling price.

The novel high-temperature water cold gas-solid separator has the following remarkable beneficial effects:

the key point of the novel high-temperature water cold gas-solid separator is that the membrane water-cooled wall of the rear wall of the hearth is bent forwards and upwards at the upper part of the hearth and extends to form a gradually-reduced sectional area with a large lower part and a small upper part, and the purpose is as follows: firstly, the sectional area of the upper hearth is reduced, the heat load of the upper hearth is improved by adding a tapered section on the upper part of the hearth, the water cooling degree is reduced, and the temperature and the smoke velocity entering a water-cooling separator are improved so as to facilitate the full combustion in a secondary combustion chamber with a large expansion space; secondly, the flue section of the descending flue is changed to be a tapered section with a large upper part (a flue gas inlet) and a small lower part (a flue gas outlet), so that the flow resistance is reduced, the expansion multiple of the descending tapered flue is enlarged, the dust-containing flue gas is suddenly enlarged and decelerated after accelerating the outlet of the descending tapered flue from a two-return high temperature, and the optimal gas-solid gravity separation effect is ensured; thirdly, not only the smoke velocity of the reducing flue at the upper part of the hearth is improved, but also the smoke velocity of the two-return-stroke high-temperature accelerating descending reducing flue is improved, the rear wall (guiding the dust-containing smoke to directly flush with the water cooling wall of the storage bin) of the two-return-stroke high-temperature accelerating descending reducing flue is also moved forwards, so that the section of the three-return-stroke ascending flue, namely the burnout chamber, is naturally enlarged, the smoke velocity is designed according to 3-less than 5m per second, the retention time of the combustible in the three-return-stroke ascending flue is prolonged, the combustible is favorably and fully burnt out, the Yangxi entrainment of the fly ash by airflow can be greatly reduced, and the initial emission concentration of the smoke dust is greatly reduced. Fourthly, the sectional area of the upper hearth is reduced, the heat load of the upper hearth is improved by adding the tapered section of the upper part of the hearth, the water cooling degree is reduced, the temperature of the outlet of the hearth can be stabilized by using natural wind for secondary wind, and the hot wind of the air preheater can be concentrated on primary wind to ensure that the temperature of the primary wind can reach 850-900 ℃ when a dense-phase region is anoxic; ensuring low oxygen and high temperature to realize the generation of ultra-low NOx.

The invention does not need any special device and separating element, and the two return strokes descend the reducing flue; an auxiliary combustion chamber (a large expansion space and a turning channel); the space of the heating surface of the burnout chamber (three return-stroke ascending flue) naturally forms a high-temperature water-cooling inertia gravity separator. The gas-solid two-phase efficient separation is realized by adopting the design of different flow velocities of the dust-containing flue gas in different flow directions from different sections behind the flue gas outlet of the hearth; namely, a dust-containing smoke guiding direct flushing bin water-cooling wall guiding gas-solid two-phase flow to a bin is arranged at a two-return smoke inlet (a hearth smoke outlet), the characteristic that solid particle combustible suspended on the upper part of a hearth is directly conveyed into the bin by airflow is formed, gas-solid two-phase flow is forced to directly flush a large expansion space from the 180-degree sharp turn of the hearth outlet and then flows to the bin, the first high-concentration solid particles directly and rapidly fall into the bottom of the bin through the centrifugal force and drag attraction of the sharp turn, then the gas-solid two-phase flow vertically and downwards in the same direction, the gravity of a body is strengthened by the blowing force of the airflow, then the gravity of the gravity and the vertical falling force from high to low make the falling flow velocity of the solid higher than the flow velocity of the airflow, most of the solid particles directly and rapidly fall into the bottom of the bin from the two-return high-temperature accelerated descending gradually-reducing flue outlet, one part of the solid fine particles are settled in the bin through the sudden expansion and deceleration gravity, and one part of the fine particles carried by the airflow are fully combusted in the secondary combustion chamber and the burnout chamber, a small amount of fine particles falling into the auxiliary combustion chamber are fully combusted continuously, and the airflow carries very limited fly ash to enter a vertical shaft flue through a flue gas outlet of the burnout chamber at a low flow speed of 3-5 meters. The gas-solid high-efficiency separation is realized without any special device and separation element.

The novel high-temperature water cold gas-solid separator has the following beneficial effects:

1. the energy consumption is ultralow, the separator does not need any special device and separation original, and the fireproof heat-insulating material and steel frame support of all cyclone separators can be saved.

2. Ultralow initial smoke and dust discharges, reduces the convection heating area deposition by a wide margin, reduces thermal resistance and flow resistance, and the operating efficiency is stable: the initial emission concentration of the smoke dust is 1800mg/m³---3000mg/m³. And the initial emission concentration of the smoke dust of the cyclone separator fluidized bed boiler is 15000mg/m³---50000mg/m³。

3. The power consumption of the induced draft fan is saved due to ultralow resistance: the local highest smoke velocity of the water-cooling inertial gravity separator is 10 meters. While the optimum flow rates for the adiabatic cyclone and the vapor-cooled circular cyclone are 25-30 meters.

4. Ultrahigh separation efficiency, and eliminating the abrasion of the convection heating surface: from the beginning of the inventionThe smoke emission concentration is 1800mg/m³---3000mg/m³(ii) a It can be concluded that eliminating the abrasion of convection heating surface is undoubted, and the service life of boiler can be prolonged.

5. Ultrahigh combustion efficiency, reduced carbon content in fly ash: the gas-solid two phases stay for a long time in the separator, and the smoke enters the auxiliary combustion chamber with a large expansion space to continuously and fully combust and burn out the combustible; and the smoke of the traditional CFB boiler enters the central cylinder in the second return cyclone cylinder, and the combustion is stopped.

The invention relates to a novel water-cooling gas-solid separation technology, which has the following inventive concept: according to the basic principle of gravity settling, the invention not only realizes the high-efficiency separation of gas and solid, but also realizes the full combustion of solid combustible in the auxiliary combustion chamber and the burnout chamber by changing the flow direction of the dust-containing flue gas from the outlet of the hearth and scientifically designing the flow velocity change of the dust-containing flue gas in different process sections.

The invention adopts a brand-new gas-solid separation principle and a brand-new water-cooling gas-solid separator structure, so that a core component of the circulating fluidized bed boiler, namely the water-cooling gas-solid separator, does not need any special device or separation element, and a high-temperature inertial gravity separator is naturally formed by a heating surface space. The breakthrough of the technology brings about all-round revolutionary change of the fluidized bed boiler, not only can greatly reduce the height of the boiler body and save the raw materials of the boiler body, but also has simple structure and advanced process; but also can solve all the pain points that the traditional fluidized bed boiler core component cyclone separator has high energy consumption of raw materials, high manufacturing and installation cost, high failure rate, high maintenance and repair cost and easy abrasion of the convection heating surface.

The technical scheme adopted by the invention for solving the technical problems in the prior art is as follows: the novel high-temperature water cold gas-solid separator consists of a two-return high-temperature accelerated downward tapered flue, an auxiliary combustion chamber, a burnout chamber (a three-return upward flue) and a material returning device; the front wall of the two-return-stroke high-temperature accelerated downward tapered flue is a forward bending point of a furnace cavity rear wall film water-cooled wall to a forward and upward bending inclined section of the furnace cavity rear wall film water-cooled wall, the rear wall of the two-return-stroke high-temperature accelerated downward tapered flue is a front wall of a dust-containing smoke direct-flushing storage bin water-cooled wall, two side walls of the two-return-stroke high-temperature accelerated downward tapered flue are symmetrical film water-cooled walls on two sides of the furnace cavity and symmetrical film water-cooled walls on two sides of the furnace cavity, the upper end of the two-return-stroke high-temperature accelerated downward tapered flue is a water-cooled ceiling or a superheater ceiling, and the lower end of the two-return-stroke high-temperature accelerated downward tapered flue is a lower transverse collecting box of the dust-containing smoke direct-flushing storage bin water-cooled wall; the front wall of the auxiliary combustion chamber is a film water-cooled wall of the rear wall of the hearth, the rear wall of the auxiliary combustion chamber is a front wall of a vertical shaft flue, and two side walls of the auxiliary combustion chamber are three-in-one bilateral symmetrical film water-cooled walls; the upper end of the auxiliary combustion chamber is the lower end of the water-cooled wall of the guide dust-containing smoke direct-flushing storage bin, and the lower end of the auxiliary combustion chamber is the upper end of the storage bin. The material returning device consists of a storage bin, a material leg, a material returning device and a material returning leg; the upper end of the bin is hermetically communicated with the lower end of the auxiliary combustion chamber, and the lower end of the bin is hermetically communicated with the upper end of the dipleg; the lower end of the dipleg is hermetically communicated with the upper end of the material returning valve; the lower end of the material returning valve is communicated with the upper end of the material returning leg in a sealing way; the lower end of the material returning leg is communicated with the film type water cooled wall of the back wall of the hearth in a sealing way.

The invention discloses a method for improving high-efficiency gas-solid separation of a novel high-temperature water cold gas-solid separator, which comprises the following steps: the smoke velocity at the outlet end of the descending tapered flue is accelerated by a large margin at high temperature in the two return strokes, the sudden expansion and deceleration speed multiplication entering the auxiliary combustion chamber is increased, the effect that the gravity of solid combustible matters is settled in the storage bin is enhanced, the full combustion in the auxiliary combustion chamber is facilitated, the smoke velocity of the burnout chamber is reduced by a large margin, the residence time of the combustible matters can be increased, the burnout degree entering the burnout chamber is improved, the Yangxi entrainment of fly ash by airflow can be reduced by a large margin, and the initial emission concentration of smoke dust is reduced by a large margin.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a front view of a scheme 1 of a four-return water-cooling flue and a water-cooling and superheater ceiling steam boiler body;

FIG. 2 is a front view of a 2 nd scheme of a four-pass water-cooled flue and water-cooled and superheater ceiling steam boiler body;

FIG. 3 is a front view of a 3 rd scheme of a four-return water-cooling flue and water-cooling ceiling steam boiler body;

FIG. 4 is a 4 th plan front view of a four-pass water-cooling flue and water-cooling ceiling steam boiler body;

FIG. 5 is a front view of a 5 th embodiment of a forced circulation tube rack type hot water boiler body with a four-pass water-cooled flue and a water-cooled ceiling;

FIG. 6 is a front view of a 6 th proposal of a four-return water-cooling flue and a superheater ceiling steam boiler body;

FIG. 7 is a front view of a 7 th proposal of a four-pass water-cooling flue and a superheated steam ceiling steam boiler body;

FIG. 8 is a front view of a double-combustion-chamber seven-return water-cooling flue and a super-heater ceiling ultra-large power station boiler body 1;

FIG. 9 is a sectional view A-A of the main body 1 of the ultra-large utility boiler of the present invention in a front view;

FIG. 10 is a 2 nd plan front view of a seven-pass water-cooled flue and superheater ceiling ultra-large utility boiler body;

FIG. 11 is a 3 rd plan front view of a seven-return water-cooling flue and a super-heater ceiling ultra-large utility boiler body;

FIG. 12 is a front view of a 1 st scheme of a direct-flow boiler body of a seven-return water-cooling flue and a super-heater ceiling ultra-large power station;

FIG. 13 is a 2 nd plan front view of a seven-return water-cooling flue and superheater ceiling ultra-large power station once-through boiler body;

FIG. 14 is a front view of a scheme 1 of a four-pass water-cooling flue and superheater ceiling once-through boiler body;

FIG. 15 is a front view of a scheme 2 of a four-pass water-cooling flue and a superheater ceiling once-through boiler body;

FIG. 16 is a front view of a water flow of a once-through boiler body with a four-pass water-cooling flue and a superheater ceiling;

FIG. 17 is a main view of a water flow of a direct-flow boiler body of a seven-return water-cooling flue and a superheater ceiling ultra-large power station;

FIG. 18 is a schematic view showing the working process of the new high-temperature water-cooled gas-solid separator according to the new structure and process of the present invention;

FIG. 19 is a schematic view showing the communication between the downcomer and the flue of the large, medium and small boilers according to the present invention;

FIG. 20 is a schematic view of the downcomer and draft tube communication of the ultra-large boiler of the present invention.

Wherein, 1-a lower transverse collecting box of a front wall of a hearth, 2-symmetrical lower longitudinal collecting boxes at two sides of the hearth, 3-a lower transverse collecting box of a rear wall of the hearth, 4-a membrane type water-cooled wall of a front wall of the hearth, 5-a membrane type water-cooled wall of a rear wall of the hearth, 6-a material returning leg, 7-a material returning valve, 8-a material returning leg, 9-a symmetrical membrane type water-cooled wall at two sides of the hearth, 10-a main combustion chamber of the hearth, 11-a material bin, 12-a symmetrical lower longitudinal collecting box at two sides (a lower flue, an ascending flue and a vertical flue), 13-a turning channel, 14-a forward bending point of the membrane type water-cooled wall of the rear wall of the hearth, 15-two-return high-temperature accelerated descending and gradually reducing flue outlets, 16-a lower transverse collecting box of a direct-flushing material bin for dust-containing flue gas, 17-a forward and upward bending inclined section of the membrane type water-cooled wall of the rear wall of the hearth, 18-a direct-flushing material bin wall for dust-containing flue gas, 19-two-return high-temperature accelerated downward tapered flue, 20-burnout chamber (three-return upward flue), 21-hearth rear wall upper transverse collecting tank, 22-communicating pipe, 23-hearth flue gas outlet, 24-hearth water-cooling ceiling (one-return water-cooling ceiling), 25-descending main pipe, 26-boiler barrel, 27-hearth two-side symmetrical upper longitudinal collecting tank, 28-hearth water-cooling ceiling upper transverse collecting tank, 29-downward flue water-cooling ceiling (two-return water-cooling ceiling), 30-superheater ceiling transverse collecting tank, 31-superheater communicating pipe, 32-superheater ceiling, 33-gas guide main pipe, 34-two-side symmetrical upper longitudinal collecting tank gas guide pipe, 35-three-in-one two-in-one (three-in-one: short for two-return high-temperature accelerated downward tapered flue 19, burnout chamber 20 and shaft flue 41), 36-transverse collecting box gas guide pipe, 37-vertical shaft front wall upper transverse collecting box, 38-economizer communicating pipe, 40-combustion chamber flue gas outlet, 41-vertical shaft flue, 42-vertical shaft flue rear wall and double hearth symmetrical front wall, 43-superheater, 44-auxiliary combustion chamber (large expansion space and turning channel), 45-vertical shaft flue front wall, 46-three-in-one bilateral symmetrical membrane water-cooling wall (three in one: two-return high-temperature acceleration descending gradual-shrinkage flue bilateral symmetrical membrane water-cooling wall, burnout chamber bilateral symmetrical membrane water-cooling wall, short for vertical shaft flue bilateral symmetrical membrane water-cooling wall), 47-steam outlet, 48-economizer, 49-water inlet, 50-vertical shaft rear wall lower transverse collecting box, 51-vertical shaft front wall lower transverse collecting box, 54-burnout chamber water-cooling ceiling (three-return water-cooling ceiling), 55-burnout chamber flue gas outlet, 56-two-in-one water-cooled ceiling upper transverse collection box (two-in-one: burnout chamber 20 and vertical shaft flue 41), 58-furnace front wall upper transverse collection box, 60-furnace water-cooled ceiling lower transverse collection box, 61-guide flue gas direct flushing storage bin water-cooled wall upper transverse collection box, 62-two-return high-temperature accelerated descending tapered flue water-cooled ceiling lower transverse collection box, 63-burnout chamber water-cooled ceiling lower transverse collection box, 67-vertical shaft water-cooled ceiling (four-return water-cooled ceiling), 68-vertical shaft water-cooled ceiling lower transverse collection box, 69-vertical shaft rear wall upper transverse collection box, 72-four-in-one water-cooled ceiling front transverse collection box, 73-partition plate, 74-furnace flue gas outlet upper transverse collection box, 75-water outlet, 76-gas collection tank, 79-superheater ceiling transverse collection box and various transverse collection boxes, 80-superheater transverse collecting box, 81-boiler front longitudinal gas guide header pipe, 82-boiler rear longitudinal gas guide header pipe, 85-descending header pipe, 87-bin rear wall transverse collecting box, 89-bin front wall transverse collecting box, 90-bin rear wall membrane water-cooled wall, 91-bin front wall membrane water-cooled wall, 92-bin rear wall lower transverse collecting box, 93-bin front wall lower transverse collecting box, 94-hearth front three-return upward flue outlet (boiler front top longitudinal wet steam cooling flue inlet), 95-high temperature superheater, 96-hearth upper longitudinal wet steam cooling flue, 97-front two-in-one two-side symmetric upper longitudinal collecting box, 98-membrane wall high temperature superheater or light tube high temperature superheater pouring refractory material seal (sealing layer), 99-two-middle-side symmetric upper longitudinal collecting box, 100-boiler top flue water-cooling ceiling, 101-furnace rear three-return upward flue outlet (boiler rear top longitudinal wet steam cooling flue inlet), 103-vertical shaft flue inlet, 104-front two-in-one bilateral symmetry lower longitudinal header, 105-furnace front wall circulating pipe, 106-furnace rear wall circulating pipe, 108-membrane water-cooling wall, 109-air distribution plate, 110-air chamber, 111-water cooling chamber bottom and primary air inlet, 112-two middle side symmetry lower longitudinal header, 113-bilateral symmetry membrane water-cooling wall, 114-bin side wall water-cooling wall lower transverse header, 115-bin side wall water-cooling wall, 116-bin side wall water-cooling wall upper transverse header, 117-four-in-one water-cooling ceiling rear transverse header, 118-four-in-one water-cooling ceiling (four-in-one: furnace main combustion chamber 10, two-return high temperature acceleration downward flue tapered 19, four-in-one water-cooling ceiling (four-in-one: furnace main combustion chamber 10, two-return high temperature acceleration downward flue tapered 19), The device comprises a burnout chamber (three-return-stroke ascending flue) 20, a vertical shaft flue 41), a 119-three-in-one superheater ceiling (a hearth, a hearth front two-return-stroke flue and a hearth rear two-return-stroke flue), a 122-six-in-one superheater ceiling (a hearth, a hearth front two-return-stroke flue, a hearth front three-return-stroke flue, a hearth rear two-return-stroke flue, a hearth rear three-return-stroke flue and a tail vertical shaft flue), a 123-transverse collecting box, a 124-hearth upper tapered section, a hearth upper tapered section of a 125-seven-return-stroke water-cooling flue, a 126-exhaust pipe, a 127-automatic exhaust valve, a 128-burnout chamber inlet, a 129-exhaust port, a 130-lower side symmetrical longitudinal collecting box, a 131-lower front-back symmetrical transverse collecting box, a 132-vertical shaft water-cooling ceiling and 133-front-back symmetrical combustion chambers.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1: referring to fig. 1, the boiler body of the present invention is two major parts of a "boiler" and a "furnace" in the conventional standard. The boiler is a pressed part for containing boiler water and steam, and comprises a closed steam-water system consisting of a boiler barrel, a water wall pipe, a membrane water wall, a convection tube bundle, a header tank, a superheater, an economizer and a pipeline, and the task of the closed steam-water system is to absorb heat energy released by fuel combustion and heat water into hot water or steam with specified temperature and pressure. "furnace" means a combustion apparatus including a plenum 110 (see fig. 10), a combustion chamber (furnace), a separator, an air preheater, a flue, and a steel frame, etc., which functions to provide a place and good conditions for fuel combustion. The "boiler" in this embodiment refers only to the drum, the membrane wall, the convection bank, the header, the superheater, the economizer and the piping. "furnace" refers only to hearths, separators, flues, etc. Other structures of the boiler can adopt the conventional boiler structure conforming to the national standard, and other parts of the boiler, such as a boiler wall, a steel frame and the like, are not described in detail.

The fluidized bed boiler with the water-cooling gas-solid separator and the four and seven return water-cooling flues comprises a hearth, a hearth main combustion chamber 10, a hearth upper tapered section 124, a two-return high-temperature accelerated downward tapered flue 19, an auxiliary combustion chamber (a large expansion space and a turning channel) 44, a burnout chamber (a three-return upward flue) 20, a return water-cooling ceiling (a hearth water-cooling ceiling) 24, a two-return water-cooling ceiling (a downward flue water-cooling ceiling) 29 and a superheater ceiling 32, a return water-cooling ceiling (a hearth water-cooling ceiling) 24, a return water-cooling ceiling (a downward flue water-cooling ceiling) 29, a three-return water-cooling ceiling (a burnout chamber water-cooling ceiling) 54 and a four-return water-cooling ceiling (a vertical shaft water-cooling ceiling) 67, the fluidized bed boiler comprises a four-in-one water cooling ceiling 118, a superheater ceiling 32, a vertical wet type steam cooling flue 96 at the upper part of a hearth, a four-return water cooling flue, a seven-return water cooling flue, an upper vertical header air duct 34, a horizontal header air duct 36 and an exhaust pipe 126 which are symmetrically arranged at two sides, and the novel high-temperature water cooling and fixing separator with the novel structure and the novel process of the various boiler bodies.

Referring to fig. 1, in the present embodiment, the fluidized bed boiler having a water-cooling gas-solid separator and four and seven return water-cooling flues further includes a water-cooling gas-solid separator, and the water-cooling gas-solid separator of the present embodiment includes a two-return high-temperature accelerated downward tapered flue 19, a burnout chamber (three-return upward flue) 20, an auxiliary combustion chamber 44, and a bunker 11; the material returning device of this embodiment includes material returning leg 6, material returning valve 7, dipleg 8.

The fluidized bed boiler with the water-cooling gas-solid separator and the four and seven return water-cooling flues also comprises a material returning device and a vertical shaft flue 41. The embodiment is a circulating fluidized bed boiler with an all-film water-cooled wall hearth, an all-film water-cooled wall ceiling, an all-film water-cooled wall separator and an all-film water-cooled wall shaft.

In this embodiment, an air distribution plate 109 is disposed at the bottom of the furnace, a main furnace chamber 10 is formed from the air distribution plate 109 at the bottom of the furnace to the lower end of the forward bending point 14 of the film-type water-cooled wall of the rear wall of the furnace at the middle upper part of the furnace, the four walls of the main furnace chamber 10 are composed of a front furnace wall film-type water-cooled wall 4, a rear furnace wall film-type water-cooled wall 5 and film-type water-cooled walls 9 symmetrical to the two sides of the furnace, the front wall of the main furnace chamber 10 is the front furnace wall film-type water-cooled wall 4, the rear wall of the main furnace chamber 10 is the rear furnace wall film-type water-cooled wall 5, and the two side walls of the main furnace chamber 10 are the film-type water-cooled walls 9 symmetrical to the two sides of the furnace.

The lower end of the film type water-cooled wall 4 of the front wall of the hearth is communicated with the lower transverse collecting box 1 of the front wall of the hearth, the upper end of the film type water-cooled wall 4 of the front wall of the hearth is bent backwards, inclined and extended upwards and is communicated with the upper transverse collecting box 28 of the water-cooled ceiling of the hearth in the radial direction to form a water-cooled ceiling 24 of the hearth, and the front end of the water-cooled ceiling 24 of the hearth is bent vertically and extended downwards and is communicated with the lower transverse collecting box 1 of the front wall of the hearth; the lower end of the film type water-cooled wall 5 of the hearth rear wall is communicated with the lower transverse collecting box 3 of the hearth rear wall, and the upper end of the film type water-cooled wall 5 of the hearth rear wall is bent forwards and upwards at a determined point and is communicated with the upper transverse collecting box 21 of the hearth rear wall; the rear end of the tapered section 124 at the upper part of the hearth is provided with a hearth flue gas outlet 23; the communicating pipes 22 at the lower end of the hearth flue gas outlet 23 are communicated with the upper transverse collecting tank 21 on the rear wall of the hearth, the communicating pipes 22 at the upper end of the hearth flue gas outlet 23 are communicated with the upper transverse collecting tank 28 on the water-cooled ceiling of the hearth, and the hearth flue gas outlet 23 is arranged on the inner sides of the two communicating pipes 22; the lower ends of the symmetrical membrane water-cooled walls 9 on the two sides of the hearth are communicated with the symmetrical lower longitudinal headers 2 on the two sides of the hearth, the upper ends of the symmetrical membrane water-cooled walls 9 on the two sides of the hearth are communicated with the symmetrical upper longitudinal headers 27 on the two sides of the hearth, heat-insulating layers are built outside the two side walls and the front wall of the hearth, and heat-insulating layers are built on the rear wall of the hearth except for a common wall. Specifically, in this embodiment, the furnace water-cooled ceiling upper horizontal collecting tank 28 is a two-in-one water-cooled ceiling upper horizontal collecting tank, and includes two horizontal collecting tanks, namely, a furnace water-cooled ceiling upper horizontal collecting tank 28 and a two-pass flue upper horizontal collecting tank.

The front wall of a two-pass high-temperature accelerated descending tapered flue 19 of the water-cooling gas-solid separator is a furnace hearth rear wall film type water-cooled wall forward and upward bending inclined section 17, the rear wall of the two-pass high-temperature accelerated descending tapered flue 19 is a guide dust-containing flue gas direct-flushing storage bin water-cooled wall 18, and two side walls of the two-pass high-temperature accelerated descending tapered flue 19 are a furnace hearth bilateral symmetry film type water-cooled wall 9 and a three-in-one bilateral symmetry film type water-cooled wall 46 respectively. In the embodiment, the lower end of the water-cooled wall 18 of the guide dust-laden gas direct flushing bunker is communicated with the lower transverse collecting box 16 of the guide dust-laden gas direct flushing bunker, the upper end of the water-cooled wall 18 of the guide dust-laden gas direct flushing bunker is bent forwards, inclined, extended upwards and radially communicated with the upper transverse collecting box 28 of the hearth water-cooled ceiling to form a down flue water-cooled ceiling 29 of the two-pass high-temperature accelerated down gradually-reduced flue 19, and the rear end of the down flue water-cooled ceiling 29 is vertically bent downwards and extends to be communicated with the lower transverse collecting box 16 of the guide dust-laden gas direct flushing bunker.

The front wall of a burnout chamber 20 of the water-cooling gas-solid separator is a water-cooling wall 18 for guiding dust-containing smoke to directly impact a storage bin, the rear wall of the burnout chamber 20 is a vertical shaft flue front wall 45, two side walls of the burnout chamber 20 are three-in-one bilateral symmetrical membrane type water-cooling walls 46, the upper end of the burnout chamber 20 is a superheater ceiling 32 or a water-cooling ceiling, and the lower end of the burnout chamber 20 is provided with a burnout chamber smoke outlet 40. The front wall of an auxiliary combustion chamber 44 of the water-cooling gas-solid separator is a furnace cavity rear wall membrane type water-cooling wall 5, the rear wall of the auxiliary combustion chamber 44 is a vertical shaft flue front wall 45, the upper end of the auxiliary combustion chamber 44 is provided with a two-return high-temperature acceleration descending tapered flue outlet 15 and a three-return ascending flue inlet (a burnout chamber flue gas inlet 128), the two-return high-temperature acceleration descending tapered flue outlet 15 is communicated with the three-return ascending flue inlet (the burnout chamber flue gas inlet 128), the lower end of the auxiliary combustion chamber 44 is the upper end of a storage bin 11, and two side walls of the auxiliary combustion chamber 44 are three-in-one bilateral symmetry membrane type water-cooling walls 46.

The stock bin 11 of the water-cooling gas-solid separator is composed of one or more trapezoid bodies with rectangular or square cross sections and large top and small bottom eccentric forward, the upper end of the front wall of the stock bin 11 is tightly sealed with the membrane type water-cooled wall 5 of the rear wall of the hearth, the upper end of the rear wall of the stock bin 11 is tightly sealed with the lower end of the front wall 45 of the shaft flue, the upper ends of two outer side walls of the stock bin 11 are tightly sealed with the three-in-one bilateral symmetry lower longitudinal header 12, the lower ends of the front wall and the rear wall of the stock bin 11 are inwards inclined and are separated by a partition plate of the stock bin 11 to form one or more trapezoid stock bins with rectangular or square cross sections and large top and small top and concentric or eccentric forward, and the lower end of the stock bin 11 is hermetically communicated with the upper ends of one or more stock legs 8. The lower end of the dipleg 8 is communicated with the upper end of the material returning valve 7 in a sealing way, the upper end of the material returning leg 6 is communicated with the lower end of the material returning valve 7 in a sealing way, and the lower end of the material returning leg 6 is communicated with the membrane type water cooled wall 5 of the back wall of the hearth in a sealing way.

The membrane type water-cooled wall 5 of the hearth rear wall at the upper part of the hearth is bent forwards and upwards to extend to the lower end of a hearth flue gas outlet 23 to be communicated with an upper transverse collecting box 21 of the hearth rear wall, a communicating pipe 22 at the upper end of the hearth flue gas outlet 23 is communicated with an upper transverse collecting box 74 of the hearth flue gas outlet, and a communicating pipe 22 at the lower end of the hearth flue gas outlet 23 is communicated with the upper transverse collecting box 21 of the hearth rear wall; the upper end of the furnace upper part tapered section 124 is provided with a four-in-one water cooling ceiling 118 or a superheater ceiling 32, the front wall of the furnace upper part tapered section 124 is a furnace front wall film type water-cooled wall 4, the rear wall of the furnace upper part tapered section 124 is provided with a furnace flue gas outlet 23, the middle lower part of the rear wall of the furnace upper part tapered section 124 is a furnace rear wall film type water-cooled wall forward and upward bending inclined section 17, and two side walls of the furnace upper part tapered section 124 are furnace bilateral symmetrical film type water-cooled walls 9.

The rear upper end of a return water-cooling ceiling 24 is communicated with the upper transverse collecting tank 28 of the hearth water-cooling ceiling in the radial direction, and the front end of the return water-cooling ceiling 24 is vertically bent downwards to extend to be communicated with the lower transverse collecting tank 1 of the front wall of the hearth.

The front end of the two-return water-cooling ceiling 29 is communicated with the upper transverse collecting box 28 of the hearth water-cooling ceiling in the radial direction, and the rear end of the two-return water-cooling ceiling 29 is vertically bent downwards to extend and is communicated with the lower transverse collecting box 16 of the guide dust-containing flue gas direct-flushing bin.

The fluidized bed boiler with the water-cooling gas-solid separator and the four-return and seven-return water-cooling flues further comprises a vertical shaft flue 41, wherein a superheater or a reheater is arranged in the vertical shaft flue 41, and superheater ceilings 32 are arranged at the top end of the burnout chamber 20 and the top end of the vertical shaft flue 41; one end of the superheater ceiling 32 communicates with the steam outlet 47, and the other end of the superheater ceiling 32 communicates with a superheater or reheater in the shaft flue 41.

The shaft flue 41 of the embodiment is composed of a shaft flue front wall 45, a shaft flue rear wall 42, a three-in-one bilateral symmetry membrane type water-cooled wall 46 and a superheater ceiling 32.

The lower end of the vertical shaft flue front wall 45 is communicated with the vertical shaft front wall lower transverse collecting box 51, and the upper end of the vertical shaft flue front wall 45 is communicated with the vertical shaft front wall transverse collecting box 37;

the lower end of the vertical shaft flue rear wall 42 is communicated with the vertical shaft rear wall lower transverse collecting box 50, and the upper end of the vertical shaft flue rear wall 42 is communicated with the vertical shaft rear wall transverse collecting box 69;

the lower extreme of the trinity bilateral symmetry membrane water-cooled wall 46 of the two side walls of the shaft flue 41 is communicated with the lower longitudinal header 12 of the trinity bilateral symmetry, and the upper end of the trinity bilateral symmetry membrane water-cooled wall 46 is communicated with the upper longitudinal header 35 of the trinity bilateral symmetry.

A superheater 32 or a reheater is arranged in a shaft flue 41 of the fluidized bed boiler, a superheater ceiling 32 is arranged at the top end of the burnout chamber 20 and the top end of the shaft flue 41, one end of the superheater ceiling 32 is communicated with a steam outlet 47, and the other end of the superheater ceiling 32 is communicated with a superheater 43 or a reheater in the shaft flue 41.

The novel high-temperature water-cooling gas-solid separation working process of the embodiment: fluidized bed combustion is a combustion of bed materials in a fluidized state, and the fuel can be fossil fuel, industrial and agricultural wastes, municipal domestic waste and various inferior fuels, biomass combustion or mixed combustion of biomass and coal. The coarse and heavy particles are burnt at the lower part of the main combustion chamber 10 of the hearth, the fine particles are burnt at the upper part of the main combustion chamber 10 of the hearth, the solid particles blown out of the flue gas outlet 23 of the hearth are forced to flow in the same direction under 180 DEG sharp rotation under the action of guiding the dust-containing flue gas to directly blow the water cooling wall 18 of the bin, the solid particles flow downwards through the two-pass high-temperature accelerated descending and reducing flue 19 to directly blow the bin 11, the first high-concentration solid particles directly and quickly fall into the bin bottom of the bin 11 at a speed higher than the air flow speed through the sharp rotation centrifugal force and drag attraction, particularly the gravity of the blowing force reinforcing body of the air flow, the attraction and the high-to-low direct falling force of the solid, the fine particles which do not fall into the bin bottom of the bin 11 are continuously burnt and subjected to radiation convection heat transfer in the secondary combustion chamber 44, the fly ash carried by the air flow is fully burnt to the smoke dust in the burning chamber 20, and the fly ash is fully burnt in the water-solid-cold gas separator under 180 DEG 2 times, The upward-turning inertial separation and the flushing collision inertial separation direct falling auxiliary combustion chamber 44 with the fork exhaust pipe bundle of the burnout chamber flue gas outlet 40 reach the stock bin 11, and are returned to the hearth main combustion chamber 10 through the dipleg 8, the material returning valve 7 and the material returning leg 6 for multiple cycles, and solid particles are fully combusted and heat transferred in the cycle process.

The smoke path of the embodiment: the flue gas passes through a hearth flue gas outlet 23, is turned sharply at 180 degrees and directly enters a two-return-stroke high-temperature accelerated downward reducing flue 19, passes through a two-return-stroke high-temperature accelerated downward reducing flue outlet 15, enters an auxiliary combustion chamber 44, passes through a turning channel 13 and enters a burnout chamber 20, the flue gas which is burned out through the burnout chamber 20 enters a vertical shaft flue 41 through a burnout chamber flue gas outlet 40, namely a water wall tube bundle fork exhaust gap at the upper end of a front wall 45 of the vertical shaft flue, passes through a flue gas outlet 43 and an economizer 48, is subjected to scouring and convection heat transfer, enters a dust remover through a smoke exhaust port 129, is subjected to flue gas staticizing, is exhausted to a chimney through an induced draft fan and enters the atmosphere.

The steam water path of the embodiment: the inlet water enters the coal economizer 48 from the water inlet 49 and enters the drum 26 through the coal economizer communicating pipe 38, the low-temperature water enters the hearth front wall lower transverse collecting tank 1, the hearth bilateral symmetrical lower longitudinal collecting tanks 2, the hearth rear wall lower transverse collecting tank 3, the three-in-one bilateral symmetrical lower longitudinal collecting tanks 12, the guide dust-laden flue gas direct flushing bin lower transverse collecting tank 16, the shaft front wall lower transverse collecting tank 51 and the shaft rear wall lower transverse collecting tank 50 through the descending branch pipes respectively, and then enters the hearth bilateral symmetrical membrane water cooling walls 9, the three-in-one bilateral symmetrical membrane water cooling walls 46, the hearth rear wall membrane water cooling walls 5, the guide dust-laden flue gas direct flushing bin water cooling walls 18, the shaft flue front walls 45 and the shaft flue rear walls 42 respectively, the hot water rises through radiation convection heat transfer, and enters the hearth two-side symmetrical upper longitudinal collecting tanks 27, the two-side symmetrical upper longitudinal collecting tanks 35, the hearth ceiling upper transverse collecting tank 28, the guide dust-laden flue gas direct flushing bin water cooling tank 28, The horizontal collecting box 37 on the front wall of the vertical shaft and the horizontal collecting box 69 on the rear wall of the vertical shaft enter the boiler barrel 26 through the air guide header pipe 33 and the air guide pipes 36 of the upper vertical collecting box and the horizontal collecting box which are symmetrical on two sides respectively, low-temperature water continues to descend and circulate, saturated steam enters the superheater ceiling 32 through the superheater communicating pipe 31, is close to the rear wall 42 of the vertical shaft flue, enters downwards from the upper end of the superheater 43 and is sent to a user through the steam outlet 47 at the lower end of the superheater 43.

Example 2: referring to fig. 2, the difference between the present embodiment and embodiment 1 is that the rear upper end of the furnace water-cooling ceiling 24 is in radial communication with the front lower portion of the drum 26, and the front upper end of the two-pass water-cooling ceiling 29 is in radial communication with the rear lower portion of the drum 26.

Example 3: referring to fig. 3, the difference between this embodiment and embodiment 1 is that the flue gas outlet 55 of the burnout chamber and the water-cooled ceiling 54 of the burnout chamber are provided, the flue gas burnt out by the burnout chamber 20 enters the shaft flue 41 through the flue gas outlet 55 of the burnout chamber (the gap between the tube bundles of the water-cooled wall at the vertical upper end of the burnout chamber 20), passes through the smoke outlet 129 of the economizer by flushing and convection heat transfer with the economizer 48, enters the dust remover, is subjected to flue gas staticization, and is discharged to the chimney by the induced draft fan to enter the atmosphere.

Another difference between this embodiment and embodiment 1 is the water-cooled ceiling 54 of the burnout chamber. The upper centers of the burnout chamber (three-pass flue) 20 and the vertical shaft flue 41 are provided with a two-in-one water-cooling ceiling upper transverse collecting box 56, the front of the two-in-one water-cooling ceiling upper transverse collecting box 56 is communicated with a burnout chamber water-cooling ceiling 54 which extends forwards to be abutted against the rear end of a down flue water-cooling ceiling 29, bends downwards for a certain distance by 90 degrees, bends backwards to form a dilution gap, extends to the position of a vertical shaft flue front wall 45, and then bends vertically downwards to extend to be communicated with a vertical shaft front wall lower transverse collecting box 51. The rear of the two-in-one water-cooled ceiling upper horizontal collecting box 56 is communicated with a shaft water-cooled ceiling 67, extends backwards to the position of the shaft flue rear wall 42, and then is vertically bent downwards to extend to be communicated with the shaft rear wall lower horizontal collecting box 50.

Example 4: referring to fig. 4, the present embodiment is different from embodiment 3 in that:

(1) the upper ends of the film type water cooled walls 4 of the front wall of the hearth are respectively communicated with an upper transverse collecting box 58 of the front wall of the hearth; the upper end of the membrane type water-cooled wall 18 of the guide dust-laden flue gas direct flushing storage bin is communicated with an upper transverse collecting box 61 of the water-cooled wall of the guide flue gas direct flushing storage bin; the upper end of the front wall 45 of the vertical shaft flue is communicated with a horizontal collecting box 37 on the front wall of the vertical shaft; the upper end of the shaft flue rear wall 42 is communicated with a shaft rear wall transverse header 69.

(2) The rear upper end of the hearth water-cooling ceiling 24 is radially communicated with the hearth water-cooling ceiling upper transverse collecting tank 28, and the front lower end of the hearth water-cooling ceiling 24 is communicated with the hearth water-cooling ceiling lower transverse collecting tank 60; the front end of the second-return water-cooling ceiling 29 is communicated with the upper transverse collecting tank 28 of the hearth water-cooling ceiling in the radial direction, and the rear end of the second-return water-cooling ceiling 29 is vertically bent downwards to extend and is communicated 62 with the lower transverse collecting tank of the second-return high-temperature accelerated descending gradually-reduced flue water-cooling ceiling; the rear upper end of the three-return water-cooled ceiling 54 is radially communicated with the two-in-one water-cooled ceiling upper transverse collecting tank 56, and the front lower end of the three-return water-cooled ceiling 54 is communicated with the burnout chamber water-cooled ceiling lower transverse collecting tank 63; the vertical shaft water-cooling ceiling 67 is longitudinally arranged at the upper ends of the upper transverse collecting box 58 of the hearth front wall, the upper transverse collecting box 21 of the hearth rear wall, the upper transverse collecting box 61 of the guide flue gas direct flushing storage bin water-cooling wall, the upper transverse collecting box 37 of the vertical shaft front wall and the upper transverse collecting box 69 of the vertical shaft rear wall, the front upper end of the vertical shaft water-cooling ceiling 67 is radially communicated with the upper transverse collecting box 28 of the hearth water-cooling ceiling, and the rear lower end of the vertical shaft water-cooling ceiling 67 is communicated with the lower transverse collecting box 68 of the vertical shaft water-cooling ceiling.

(3) The number of the communicating pipes 22 is multiple, the lower horizontal collecting box 60 of the hearth water-cooling ceiling is communicated with the upper horizontal collecting box 58 of the front wall of the hearth through the communicating pipes 22, the lower horizontal collecting box 62 of the two-pass high-temperature accelerated downward gradually-reduced flue water-cooling ceiling is communicated with the upper horizontal collecting box 61 of the water-cooling wall of the guide flue gas direct-flushing storage bin through the communicating pipes 22, and the lower horizontal collecting box 68 of the shaft water-cooling ceiling is communicated with the horizontal collecting box 69 of the rear wall of the shaft through the communicating pipes 22; the water-cooled ceiling lower horizontal header 63 of the burnout chamber is communicated with the vertical shaft front wall horizontal header 37 through a communicating pipe 22.

(4) A superheater 43 is installed at the upper end entrance of the shaft flue 41.

Example 5: referring to fig. 5, the present embodiment is a forced circulation tube rack type hot water boiler, which is different from embodiment 4: in the embodiment, an upper transverse collecting box 28 and a transverse collecting box air duct 36 of a hearth water-cooling ceiling are removed, a hearth water-cooling ceiling 24, a downward flue water-cooling ceiling 29, a lower transverse collecting box 68 of a vertical shaft water-cooling ceiling, a vertical shaft water-cooling ceiling 67, a lower transverse collecting box 60 of the hearth water-cooling ceiling, an upper transverse collecting box 61 of a water-cooling wall of a guide flue gas direct flushing storage bin, a lower transverse collecting box 63 of a burnout chamber water-cooling ceiling, a lower transverse collecting box 68 of the vertical shaft water-cooling ceiling and a superheater 43 are removed, the upper transverse collecting box 58 of the front wall of the hearth, the upper transverse collecting box 69 of the rear wall of the vertical shaft and the lower end of an upper longitudinal collecting box are removed, and the upper transverse collecting box 28 of the hearth water-cooling ceiling is replaced into an upper transverse collecting box 74 of a hearth flue gas outlet, an upper transverse collecting box 61 of the water-cooling wall of the guide flue gas direct flushing storage bin and a front transverse collecting box 72 of the four water-cooling ceiling; at the upper end of the upper longitudinal header, the water-cooled ceiling is replaced by a four-in-one water-cooled ceiling 118; secondly, a partition plate 73 is added; thirdly, the directions of circulating water paths of the coal economizer 48 are different; the four-in-one water-cooled ceiling rear transverse collecting tank 117 is replaced by the boiler barrel 26, the position of the four-in-one water-cooled ceiling rear transverse collecting tank 117 is arranged at the rear upper end of the boiler body, and the gas collecting tank 76 is additionally arranged, wherein the four-in-one water-cooled ceiling 118 is longitudinally arranged at the upper ends of the hearth front wall upper transverse collecting tank 58, the hearth rear wall upper transverse collecting tank 21, the guide smoke direct flushing bin water-cooled wall upper transverse collecting tank 61, the shaft front wall upper transverse collecting tank 37 and the shaft rear wall upper transverse collecting tank 69, the front end of the four-in-one water-cooled ceiling 118 is communicated with the four-in-one water-cooled ceiling front transverse collecting tank 72, the rear end of the four-in-one water-cooled ceiling 118 is communicated with the four-in-one water-cooled ceiling rear transverse collecting tank 117, the water outlet 75 is communicated with the upper center of the four-in-one water-cooled ceiling 117, the exhaust pipes 126 are communicated with the automatic exhaust valves 127 through the four-in-one water-cooled ceiling 118, and the hearth ceiling 32 is longitudinally arranged on the hearth front wall upper transverse collecting tank 58, The upper ends of the hearth rear wall upper transverse collecting box 21, the guide flue gas direct flushing bin water wall upper transverse collecting box 61, the vertical shaft front wall upper transverse collecting box 37 and the vertical shaft rear wall upper transverse collecting box 69 are arranged on the hearth rear wall, the front end of the superheater ceiling 32 is communicated with the steam outlet 47, the rear end of the superheater ceiling 32 is communicated with the reheater, and the air guide pipes penetrate through the superheater ceiling 32 and are communicated with the air guide main pipe 33.

In the forced circulation tube rack type hot water boiler of the embodiment, the front end of the four-in-one water-cooling ceiling 118 is communicated with the front horizontal collecting tank 72 of the four-in-one water-cooling ceiling, the rear end of the four-in-one water-cooling ceiling 118 is communicated with the rear horizontal collecting tank 117 of the four-in-one water-cooling ceiling, the water outlet 75 is communicated with the upper center of the rear horizontal collecting tank 117 of the four-in-one water-cooling ceiling, and the exhaust pipes 126 are communicated with the automatic exhaust valve 127 through the four-in-one water-cooling ceiling 118.

The water path of the forced circulation pipe rack type hot water boiler of the embodiment is as follows: the inlet water enters the economizer 48 from the water inlet 49, enters the vertical shaft back wall transverse collecting tank 69 through the communicating pipe 77, is distributed to the vertical shaft flue back wall 42 to descend into the vertical shaft back wall lower transverse collecting tank 50, then enters the three-in-one bilateral symmetry lower longitudinal collecting tank 12 through the communicating pipe 22, enters the three-in-one bilateral symmetry membrane type water-cooling wall 46 through the rear part of the partition plate 73, ascends into the rear part of the three-in-one bilateral symmetry upper longitudinal collecting tank 35 through the communicating pipe, then forcibly enters the vertical shaft flue front wall 45 through the rear part of the partition plate 73, descends into the vertical shaft front wall lower transverse collecting tank 51, then enters the three-in-one bilateral symmetry lower longitudinal collecting tank 12 through the communicating pipe 22, forcibly distributes to the guide dust-containing flue gas straight flushing storage bin 18 through the partition plate 73, ascends into the middle part of the three-in-two bilateral symmetry upper longitudinal collecting tank 35 through the partition plate 73, forcibly enters the guide flue gas straight flushing storage bin water-cooling wall upper transverse collecting tank 61 through the communicating pipe 22 through the partition plate 73, forcibly distributes to the guide dust-containing flue straight flushing storage bin 18 through the partition plate 73, descends into the guide straight flushing storage bin lower straight flushing storage bin The transverse collecting box 16 enters the front section of the three-in-one bilateral symmetric lower longitudinal collecting box 12 through the communicating pipes 22 at two ends, is forcibly distributed to the three-in-one bilateral symmetric membrane type water-cooled wall 46 to move upwards to enter the front section of the three-in-one bilateral symmetric upper longitudinal collecting box 35 through the partition plate 73, enters the two-side communicating pipes 22 through the partition plate 73, then enters the two-side communicating pipes 22, enters the upper transverse collecting box 21 of the rear wall of the hearth, is distributed to the inclined section 17 of the rear wall of the hearth, which is bent forwards and upwards, and the membrane type water-cooled wall 5 of the rear wall of the hearth, moves downwards to enter the lower transverse collecting box 3 of the rear wall of the hearth, enters the two-side symmetric lower longitudinal collecting box 2 of the hearth and the lower transverse collecting box 1 of the front wall of the hearth through the communicating pipes 22, forcibly moves upwards to the upper end through the upper longitudinal collecting boxes 27 of the two-side symmetric upper transverse collecting boxes of the hearth, the front wall 4 of the hearth, respectively enters the collecting box 58 through the communicating pipes 22, then enters the front transverse collecting box 72 of the four-in-one water-in-water-cooling ceiling 118, and then redistributes the front transverse collecting box 72 of the four-in-cooling ceiling 118 Enters a four-in-one water-cooling ceiling rear transverse collecting box 117 and is sent to a heating system through a gas collecting tank 76 and a water outlet 75 in sequence.

Example 6: referring to fig. 6, the present embodiment is different from embodiment 1 in that: in the embodiment, an upper transverse collecting box 28 of the hearth water-cooling ceiling is removed, the hearth water-cooling ceiling 24 and the two-return-stroke flue water-cooling ceiling 29 are removed, and the hearth water-cooling ceiling, the two-return-stroke flue water-cooling ceiling and the three-return-stroke flue water-cooling ceiling are changed into a three-in-one (hearth, two-return-stroke flue and three-return-stroke flue) superheated steam ceiling 32. The upper part of the three-return flue is additionally provided with a superheater 119; the ceiling of the shaft flue is a water-cooled ceiling 132.

Example 7: referring to fig. 7, the present embodiment is different from embodiment 1 in that: firstly, the hearth water-cooling ceiling 24 and the secondary return water-cooling ceiling 29 are changed into a superheater ceiling 32; secondly, the position of the drum 26 is changed into an eccentric position; thirdly, a longitudinal air guide header 81 at the front part of the boiler, a longitudinal air guide header 82 at the rear part of the boiler, a lower part of the boiler barrel 26 and a transverse collecting box 123 are communicated through a communicating pipe 22, and lower parts of two side ends of the transverse collecting box 123 are communicated with a descending header 85.

Example 8: referring to fig. 8, the present embodiment is an ultra-large utility boiler, which is different from embodiment 7 in that: firstly, the lower part of a hearth is respectively communicated with a lower transverse collecting box 1 on the front wall of the hearth and a lower transverse collecting box 3 on the rear wall of the hearth through the lower ends of a front symmetrical membrane wall tube bundle 108 and a rear symmetrical membrane wall tube bundle 108 of the hearth, the upper ends of the front symmetrical membrane wall tube bundle and the rear symmetrical membrane wall tube bundle are respectively communicated with a transverse collecting box 107 to respectively form an air chamber 110, a water-cooling air chamber bottom, a primary air inlet 111, an air distribution plate 109 and a front-rear symmetrical combustion chamber 133, and circulating tubes 105 and 106 are respectively communicated with an upper transverse collecting box 74 on a smoke outlet of the hearth; a group of new symmetrical high-temperature water-cooling gas-solid separators are added between the film water-cooled wall 4 on the front wall of the hearth and the film water-cooled wall 5 on the rear wall of the hearth; the new high-temperature water cold gas-solid separator comprises a two-return high-temperature accelerated descending tapered flue 19, an auxiliary combustion chamber (large expansion space and turning channel) 44, a burnout chamber (three-return ascending flue) 20, a front two-in-one upper longitudinal collecting box 97 with two symmetrical sides and a front two-in-one lower longitudinal collecting box 104 with two symmetrical sides; thirdly, a longitudinal wet-type water vapor cooling flue 96 which is communicated with the vertical shaft flue 41 and is arranged at the top of the boiler is added, specifically, the four-return water cooling flue comprises a return hearth main combustion chamber 10 to a hearth flue gas outlet 23, a two-return high-temperature accelerated descending reducing flue 19, a three-return ascending flue 20 and a boiler tail convection flue, the three-return-stroke ascending flue 20 is a burnout chamber, the convection flue at the tail part of the boiler is a vertical shaft flue 41, the seven-return water-cooling flue comprises a return hearth main combustion chamber 10 to a hearth flue gas outlet 23, a two-return high-temperature accelerated descending tapered flue 19 in front of the hearth, a two-return high-temperature accelerated descending tapered flue 19 in back of the hearth, a three-return ascending flue 20 in front of the hearth, a three-return ascending flue 20 in back of the hearth, a longitudinal wet-type water vapor cooling flue 96 in the upper part of the hearth and a convection flue at the tail part of the boiler, wherein the convection flue at the tail part of the boiler is a vertical shaft flue 41;

fourthly, the lower wall of the longitudinal wet-type water vapor cooling flue 96 at the upper part of the hearth is a high-temperature superheater 95, the upper wall of the longitudinal wet-type water vapor cooling flue 96 at the upper part of the hearth is a boiler top flue water-cooling ceiling 100, the side walls of the longitudinal wet-type water vapor cooling flue 96 at the upper part of the hearth are symmetrical membrane water-cooling walls 9, 113 and 46 at two sides of the hearth, and the front wall and the rear wall of the longitudinal wet-type water vapor cooling flue 96 at the upper part of the hearth are respectively the upper parts of the vertical shaft flue rear walls 42 which are symmetrical front and rear; fifthly, a front three-return-stroke ascending flue outlet 94 of the hearth and a rear three-return-stroke ascending flue outlet 101 of the hearth are symmetrical, and flue gas simultaneously enters a longitudinal wet-type water vapor cooling flue 96 at the upper part of the hearth from the front three-return-stroke ascending flue outlet 94 of the hearth and the rear three-return-stroke ascending flue outlet 101 of the hearth respectively and is discharged through a vertical shaft flue 41; sixthly, two sides of the bin side wall water-cooled walls 115 are added to the bin 11, the upper ends of the bin side wall water-cooled walls 115 are communicated with the upper cross collecting box 116 of the bin side wall water-cooled walls, the lower ends of the bin side wall water-cooled walls 115 are communicated with the lower cross collecting box 114 of the bin side wall water-cooled walls, and the three-in-one bilateral symmetry lower cross collecting box 12 is communicated with the upper cross collecting box 116 of the bin side wall water-cooled walls through the communicating pipe 22. The embodiment is suitable for being adopted when the depth of the furnace chamber in the ultra-large boiler is overlarge.

The upper end of a front three-return-stroke ascending flue (an upper burnout chamber) of a hearth in a burnout chamber 20 of the ultra-large power station boiler is a front three-return-stroke ascending flue outlet 94 of the hearth, the front three-return-stroke ascending flue outlet 94 of the hearth is an inlet of a longitudinal wet-type water vapor cooling flue at the front top of the boiler, a high-temperature superheater 95 is arranged at the position of the front three-return-stroke ascending flue outlet 94 of the hearth, the lower end of the front three-return-stroke ascending flue of the hearth is a front three-return-stroke flue inlet 128 of the hearth, the front three-return-stroke flue inlet 128 of the hearth is communicated with an outlet 15 of a two-return-stroke high-temperature accelerated descending tapered flue, the front end of the front three-return-stroke ascending flue of the hearth is a symmetrical vertical shaft flue rear wall 42, the rear end of the front three-return-stroke ascending flue of the hearth is a water cooling wall 18 for guiding dust-containing flue directly rushing the storage bin, and two side ends of the front three-return-stroke ascending flue of the hearth are bilaterally symmetrical membrane water cooling walls 113; the upper end of a three-return-stroke ascending flue (an upper burnout chamber) at the back of a hearth is a three-return-stroke ascending flue outlet 101 at the back of the hearth, the three-return-stroke ascending flue outlet 101 at the back of the hearth is a longitudinal wet-type water vapor cooling flue inlet at the top of a boiler, a high-temperature superheater 95 is arranged at the position of the three-return-stroke ascending flue outlet 101 at the back of the hearth, the lower end of the three-return-stroke ascending flue at the back of the hearth is a three-return-stroke flue inlet 128 at the back of the hearth, the three-return-stroke flue inlet 128 at the back of the hearth is communicated with a two-return-stroke high-temperature accelerating descending reducing flue outlet 15, the front end of the three-return-stroke ascending flue at the back of the hearth is a guide dust-containing flue direct-flushing storage bin water-cooling wall 18, the rear membrane type ascending flue at the back of the hearth is a vertical shaft flue front wall 45, and the two side ends of the three-stroke ascending flue at the back of the hearth are bilaterally symmetrical water-cooling walls 113.

Specifically, in this embodiment, the upper wall of the longitudinal wet steam cooling flue 96 on the upper portion of the furnace is a water-cooled ceiling 100 of a top flue of the boiler, the lower wall high-temperature superheater 95 of the longitudinal wet steam cooling flue 96 on the upper portion of the furnace is a light pipe high-temperature superheater (the gap between the pipe and the pipe is a flue gas channel) which is close to the front three-pass upward flue outlet 94 of the furnace, the rear three-pass upward flue outlet 101 of the furnace and the vertical flue inlet 103, the high-temperature superheater 95 is close to the top end of the furnace and the upper ends of the two-pass high-temperature accelerated downward tapered flues 19 which are symmetrical in the front and the rear are cast refractory material seals (sealing layers) 98 of the membrane wall high-temperature superheater or the light pipe high-temperature superheater, and two side walls of the longitudinal wet steam cooling flue 96 on the upper portion of the furnace are bilaterally symmetrical membrane water-cooled walls 113.

The flue of the ultra-large power station boiler of the embodiment: the flue gas simultaneously passes through two symmetrical front and back hearth flue gas outlets 23, enters two symmetrical front and back two-return high-temperature accelerated descending tapered flues 19 in a 180-degree sharp-turn straight-down manner, naturally settles a large amount of solid particles in the bin 11 through the sudden large expansion and deceleration of the two symmetrical front and back two-return high-temperature accelerated descending tapered flue outlets 15 of the hearth, continuously burns the fine particles which are not settled in the bin 11 in the two symmetrical front and back auxiliary combustion chambers 44 of the hearth, the fly ash carried by the airflow enters two symmetrical front and back burnout chambers 20 of the hearth, the flue gas continuously burnt out by the burnout chamber 20 enters the longitudinal wet-type water vapor cold flue 96 at the upper part of the hearth through the gap between the three return ascending flue outlets 94 of the front and back symmetrical hearth and the three return ascending flue outlets 101 of the back hearth through the high-temperature superheater 95, then enters the vertical flue 41 at the tail part, enters the dust remover through the smoke exhaust port 129 and the flue gas static heat transfer through the scouring and convection with the superheater 43 and the economizer 48, and the smoke remover The fan discharges to the chimney and enters the atmosphere.

The steam-water path of the ultra-large power station boiler of the embodiment comprises the following steps: inlet water enters the economizer 48 from a water inlet 49, the economizer 48 enters a flue water-cooling ceiling 100 at the top of the boiler through a communicating pipe and then enters the boiler barrel 26 through the communicating pipe, low-temperature water respectively enters the descending branch pipes through a descending header pipe 85, the low-temperature water respectively enters the lower longitudinal and transverse collecting boxes through the descending branch pipes and then enters the longitudinal and transverse membrane water-cooling walls to transfer heat through radiation convection, hot water rises and respectively enters the upper longitudinal and transverse collecting boxes, and then respectively enters the air guide branch pipes through the air guide pipes of the upper longitudinal and transverse collecting boxes and respectively enters the boiler barrel 26 through the air guide branch pipes, the low-temperature water continuously descends and circulates, and saturated steam enters the high-temperature superheater 95 and the superheater 43 through the communicating pipe and is sent to a user through a steam outlet 47.

FIG. 9 is a sectional view taken along line A-A; mainly in order to match with figure 8, the mutual position relationship of the drum 26, the longitudinal gas guide main pipe 82 at the rear part of the boiler, the communicating pipe 22, the transverse header 123, the descending main pipe 85, the upper longitudinal header gas guide pipes 34 at two sides and the transverse header gas guide pipes 36 is found out.

Example 9: referring to fig. 10, the present embodiment is different from embodiment 8 in that: the embodiment eliminates the horizontal header 123; the drum 26 is lengthened and the drum 26 is greater than the width of the boiler.

Example 10: referring to fig. 11, the present embodiment is different from embodiment 10 in that: in the present embodiment, superheaters 43 are respectively added to the upper parts of the two burnout chambers 20 which are symmetrical in front and back.

Example 11: referring to fig. 12, the present embodiment is different from embodiment 11 in that: the embodiment is a forced circulation once-through boiler, and a boiler barrel is removed. And example 11 is a drum type natural circulation boiler.

Example 12: referring to fig. 13, the present embodiment is different from embodiment 12 in that: in the present embodiment, superheaters 43 are respectively added to the upper parts of the two burnout chambers 20 which are symmetrical in front and back.

Example 13: referring to fig. 14, the present embodiment is different from embodiment 6 in that: the present embodiment is a drum-less forced circulation once-through boiler.

Example 14: referring to fig. 15, the present embodiment is different from embodiment 14 in that: in the embodiment, a three-in-one superheater ceiling 119 is additionally arranged in the three-return flue behind the hearth.

Example 15: referring to fig. 16, the present embodiment is different from embodiment 14 in that: the embodiment is a flow chart of a water vapor circuit of a forced circulation once-through boiler.

The once-through boiler steam circuit of the four-return water-cooling flue of the embodiment: inlet water enters the economizer 48 from a water inlet 49, enters the transverse collecting tank 123 through a communicating pipe 31, and then enters the symmetrical lower longitudinal collecting tanks 2 at the two sides of the hearth, the lower transverse collecting tank 1 at the front wall of the hearth and the lower transverse collecting tank 3 at the rear wall of the hearth through the communicating pipe 22 respectively. The water distribution of the symmetrical lower longitudinal header 2 at the two sides of the hearth is distributed to symmetrical membrane water walls 9 at the two sides of the hearth to ascend to symmetrical upper longitudinal headers 27 at the two sides of the hearth and then all the partition plates 73 go downwards to symmetrical upper longitudinal headers 27 at the two sides of the hearth and then all the partition plates go backwards to the three-in-one symmetrical lower transverse headers 12 and then go backwards to the rear end to be communicated with the vertical shaft rear wall lower transverse header 50 through the communicating pipe 22, part of superheated steam rises to the three-in-one symmetrical upper transverse header 35 at the two sides through the three-in-one symmetrical membrane water walls 46 and then is communicated with the superheater transverse header 79 through the communicating pipe 31, and part of superheated steam is distributed to the vertical shaft rear wall 42 to the vertical shaft rear upper transverse header 69 through the communicating pipe 31 and then is communicated with the transverse header 79 through the two communicating pipes, enters the superheater 43 through the two communicating pipes and goes downwards to be sent to required equipment through the steam outlet 47.

Water in the lower transverse collecting tank 1 on the front wall of the hearth and the lower transverse collecting tank 3 on the rear wall of the hearth is respectively distributed to the film-type water-cooled wall 4 on the front wall of the hearth and the film-type water-cooled wall 5 on the rear wall of the hearth and then respectively rises to the upper transverse collecting tank 58 on the front wall of the hearth and the upper transverse collecting tank 21 on the rear wall of the hearth; the upper transverse header 58 on the front wall of the hearth is communicated with the superheater ceiling header 79 through a communicating pipe 22; the upper transverse collecting tank 21 on the rear wall of the hearth is communicated with the superheater ceiling collecting tank 79 through a communicating pipe 22; two paths of water of the front and the rear collecting boxes of the hearth enter a superheater ceiling 122 through a communicating pipe 22 and then enter a transverse collecting box 79, the transverse collecting box 79 of the superheater is communicated with an upper transverse collecting box 61 of a guide smoke direct flushing bin through a superheater communicating pipe 31, the water is distributed to a bundle of the guide smoke direct flushing bin and then enters a lower transverse collecting box 16, the lower transverse collecting box 16 is communicated with a transverse collecting box 89 on the front wall of the bin through the communicating pipe 22 and is distributed to a membrane water-cooled wall 91 on the front wall of the bin to descend into a lower transverse collecting box 93 on the front wall of the bin, is communicated with a lower transverse collecting box 92 on the rear wall of the bin through the communicating pipe 31 and is distributed to a membrane water-cooled wall 90 on the rear wall of the feeding bin, then ascends into the transverse collecting box 87 on the rear wall of the bin, is communicated with a lower transverse collecting box 51 on the front wall of the shaft through the communicating pipe 22 and is distributed to a front wall 45, then ascends into the transverse collecting box 37 on the front wall of the shaft and is communicated with a superheater collecting box 79 through the communicating pipe 31 and is distributed to a superheater 43, and then down through the steam outlet 47 to the desired equipment.

The embodiment is a general steam flow path according to the rule of the forced circulation once-through boiler, and is only a directional scheme.

Example 16: referring to fig. 17, the present embodiment is different from embodiment 16 in that: the embodiment is a flow chart of a double-hearth forced circulation water steam circuit.

The water vapor path of the ultra-large power station boiler of the embodiment comprises: inlet water enters the economizer 48 from a water inlet 49, enters the transverse collecting tank 123 through a communicating pipe 31, and then enters the symmetrical lower longitudinal collecting tanks 2 at the two sides of the hearth, the lower transverse collecting tank 1 at the front wall of the hearth and the lower transverse collecting tank 3 at the rear wall of the hearth through the communicating pipe 22 respectively. The water distribution of the symmetrical lower vertical header 2 at the two sides of the furnace chamber is distributed to the symmetrical membrane water walls 9 at the two sides of the furnace chamber, ascends to the symmetrical upper vertical header 99 at the two sides of the furnace chamber, moves forward to the partition 73, redistributes to the symmetrical upper vertical header 46 at the two sides of the three-in-one, enters the symmetrical upper vertical header 97 at the two sides of the three-in-one, moves backward to the partition 73, redistributes to the symmetrical upper vertical header 35 at the two sides of the three-in-one, enters the symmetrical lower vertical header 12 at the two sides of the three-in-one, moves backward to the rear end, distributes to the symmetrical upper vertical header 35 at the two sides of the three-in-one, and then communicates with the superheater header 79 through the communication pipe 31, and redistributes to the superheater 43 and moves downward to the steam outlet 47.

Water in the lower transverse collecting box 1 on the front wall of the hearth and the lower transverse collecting box 3 on the rear wall of the hearth is respectively distributed to the membrane type water-cooled wall 4 on the front wall of the hearth, the membrane type water-cooled wall 5 on the rear wall of the hearth and the membrane type water-cooled wall 108 to rise to the upper transverse collecting box 21 on the front wall of the hearth and the upper transverse collecting box 21 on the rear wall of the hearth; the three-in-one superheater ceiling 119 is communicated and distributed to move forwards to enter the front transverse collecting box 79 of the superheater ceiling through a communicating pipe 31 and a rear transverse collecting box 79 of the superheater ceiling, and then communicated and distributed to move downwards to enter a lower transverse collecting box 16 of a guide smoke direct flushing bin through a communicating pipe 22 and a guide smoke direct flushing bin upper transverse collecting box 61 and then communicated with a bin rear wall transverse collecting box 87 through the communicating pipe 22; the silo rear wall horizontal collection box 87 is communicated with a silo rear wall lower horizontal collection box 50 through a communication pipe 31 and distributed to a silo flue rear wall and a double-hearth symmetrical front wall 42 to ascend into the silo rear wall horizontal collection box 69 and then communicated with a superheater ceiling horizontal collection box 79 through a communication pipe 22 and distributed to a three-in-one superheater ceiling 119 to ascend into the superheater ceiling rear horizontal collection box 79, communicated with a guide smoke direct flushing silo upper horizontal collection box 61 through a communication pipe 31 and distributed to a guide dust-containing smoke direct flushing silo water-cooling wall 18 to descend into a guide smoke direct flushing silo lower horizontal collection box 16, the silo lower horizontal collection box 16 is communicated with a silo front wall horizontal collection box 89 through a communication pipe 22, communicated with the silo front wall lower horizontal collection box 51 and the silo rear wall lower horizontal collection box 50 through a communication pipe 31 respectively and distributed to the silo flue wall 42 to ascend into the silo front wall upper horizontal collection box 37 and the silo rear wall upper horizontal collection box 69 through a communication pipe 31 and communicated with the superheater 79 to descend into the silo front wall horizontal collection box 79 through a communication pipe 31 respectively And a steam outlet 47.

FIG. 18 is a schematic view showing the working flow of the new high-temperature water-cooled gas-solid separator according to the new structure and new process of the present invention; the work flow has already been illustrated in example 1.

FIG. 19 is a schematic view showing the communication between the downcomer and the flue of the large, medium and small boilers according to the present invention; in the figure, A is a descending manifold, B is a descending branch, C is an airway tube, and E is an airway branch. The lower ends of the descending branch pipes B are respectively communicated with the lower longitudinal collecting box and the lower transverse collecting box, and the upper ends of the descending branch pipes B are respectively communicated with the descending main pipe A.

The lower end of the air duct C is respectively communicated with the longitudinal header and the transverse header, and the upper end of the air duct C is respectively communicated with the air duct branch pipe E.

FIG. 20 is a schematic view of the downcomer and draft tube communication of the ultra-large boiler of the present invention; in the figure, A is a descending main pipe, B is a descending branch pipe, C is an upper transverse header air duct, D is an upper longitudinal header air duct, and E is an air duct branch pipe. The lower ends of the descending branch pipes B are respectively communicated with the lower longitudinal collecting box and the lower transverse collecting box, and the upper ends of the descending branch pipes B are respectively communicated with the descending main pipe A.

The lower end of the upper transverse collecting tank air duct C is communicated with the upper transverse collecting tank, and the upper end of the upper transverse collecting tank air duct C is communicated with the air guide branch pipe E. The lower end of the upper longitudinal header air duct D is communicated with the upper longitudinal header, and the upper end of the upper longitudinal header air duct D is communicated with the air duct branch pipe E.

In the embodiments 1 to 16, the four wall surfaces of the downward tapered flue 19 need to be subjected to anti-abrasion treatment at the position of the four walls of the upper part of the hearth with the speed more than 5M and at the high temperature of two return strokes. The heat insulating layers are completely added on the four walls of the secondary combustion chamber 44 and the three return flues 20 of the burnout chamber from the four walls of the tapered section 17 at the upper part of the hearth to the four walls of the two return downward tapered flues.

The water-cooled wall 18 of the dust-laden flue gas guiding direct-flushing storage bin in the embodiments 1 to 16 can be any one of a full-film water-cooled wall structure, a semi-film water-cooled wall structure, a full-light-tube pouring refractory material structure and a dry refractory wall structure, and the internal and external structures of the water-cooled gas-solid separator can be rectangular or square; the four walls of the hearth main combustion chamber 10 can be any one of a full-film water-cooled wall structure, a semi-film water-cooled wall structure and a full-light tube pouring refractory material structure, and the inner and outer structures can be rectangular and square; the four walls of the shaft flue 41 may be any one of a full-film water-cooled wall structure, a semi-film water-cooled wall structure, a full-light-tube poured refractory material structure, and a dry refractory wall structure.

The fuel inlet, the desulfurizer inlet, the slag discharge port, the circulating material inlet, the air distribution plate, the primary air inlet, the secondary air inlet, the hearth flue gas outlet, the furnace door, the explosion door, the observation hole, the measuring hole, the access hole and the like in the embodiments 1 to 16 are designed according to the standard of the prior art.

The furnace water wall tube water circulation, the separator water wall tube water circulation, the shaft water wall tube water circulation, the steel frame and the heat insulation of the embodiments 1 to 16 are designed according to the existing general technical standard.

The rear wall of the tapered section 124 of the upper part of the hearth of the four-return water-cooling flue is the forward bending point 14 to the top end of the film-type water-cooling wall of the rear wall of the hearth, the front wall of the tapered section 124 of the upper part of the hearth of the four-return water-cooling flue is the front wall of the hearth, and the two side walls of the tapered section 124 of the upper part of the hearth of the four-return water-cooling flue are the symmetrical film-type water-cooling walls 9 on the two sides of the hearth; the front wall of the tapered section 125 of the upper part of the hearth of the seven-return water-cooling flue is the forward bending point 14 of the membrane water-cooling wall of the rear wall of the hearth to the top end, and the rear wall of the tapered section 125 of the upper part of the hearth of the seven-return water-cooling flue is the forward bending point 14 of the membrane water-cooling wall of the rear wall of the hearth to the top end.

The upper parts of the boiler barrels 26 of the steam boiler and the power station boiler are communicated with an air guide pipe, the lower parts of the boiler barrels 26 are communicated with a downcomer, all the lower longitudinal collecting boxes and the transverse collecting boxes are communicated with the matched downcomer, and all the upper longitudinal collecting boxes and the transverse collecting boxes are communicated with the matched air guide pipe. The fluidized bed boiler with the water-cooling gas-solid separator and the four-and seven-return water-cooling flues respectively comprises water-cooling ceilings and superheater ceilings 32 which are reserved with pipe through holes correspondingly matched with a steam guide pipe and an exhaust pipe, and the boiler barrel can be arranged at the front end and the rear end of the top end of the boiler body and at any position longitudinally beneficial to arranging a downcomer. The hot water boiler is designed according to the prior general technology.

All the different structures and different parts of the embodiments 1 to 16 can be mutually adopted and mutually optimized to form a new furnace type.

While the foregoing has described the principles of the invention and its preferred embodiments, it is to be understood that this invention is not limited to the disclosed embodiments, which are presented by way of illustration and not of limitation, but rather can be embodied in many forms without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The fluidized bed boiler with the water-cooling gas-solid separator, the four-return-stroke water-cooling flues and the seven-return-stroke water-cooling flues comprises a hearth, a main hearth chamber (10), a tapered section (124) at the upper part of the hearth, a two-return-stroke high-temperature accelerating downward tapered flue (19), an auxiliary hearth chamber (44), a burnout chamber (20), a one-return-stroke water-cooling ceiling (24), a two-return-stroke water-cooling ceiling (29), a superheater ceiling (32), a one-return-stroke water-cooling ceiling (24), a two-return-stroke water-cooling ceiling (29), a three-return-stroke water-cooling ceiling (54) and a four-return-stroke water-cooling ceiling (67), a four-in-one water-cooling ceiling (118) and a superheater ceiling (32), a six-in-one superheater ceiling (122), A longitudinal wet type water vapor cooling flue (96) at the upper part of the hearth, a four-return water cooling flue, a seven-return water cooling flue, an upper longitudinal header gas guide pipe (34), a transverse header gas guide pipe (36) and an exhaust pipe (126) which are symmetrically arranged at two sides; the fluidized bed boiler is characterized in that the water-cooling gas-solid separator and the four-and seven-return water-cooling flues also comprise the water-cooling gas-solid separator, and the water-cooling gas-solid separator comprises a two-return high-temperature accelerated descending tapered flue (19), an auxiliary combustion chamber (44), a burnout chamber (20) and a storage bin (11).

2. A fluidized bed boiler with a water-cooled gas-solid separator and four and seven return water-cooled flues as claimed in claim 1, wherein the bottom of the furnace chamber is provided with an air distribution plate (109), and the main combustion chamber (10) of the furnace chamber is formed from the air distribution plate (109) at the bottom of the furnace chamber to the lower end of the forward bending point (14) of the film-type water-cooled wall at the middle upper part of the furnace chamber; a hearth flue gas outlet (23) is arranged at the rear end of the tapered section (124) at the upper part of the hearth, the front wall of the main hearth combustion chamber (10) is a hearth front wall film type water-cooled wall (4), the rear wall of the main hearth combustion chamber (10) is a hearth rear wall film type water-cooled wall (5), and the two side walls of the main hearth combustion chamber (10) are hearth bilateral symmetrical film type water-cooled walls (9);

the membrane type water-cooled wall (5) of the hearth rear wall at the upper part of the hearth is bent forwards and upwards to extend to the lower end of a hearth flue gas outlet (23) to be communicated with an upper transverse collecting box (21) of the hearth rear wall, a communicating pipe (22) at the upper end of the hearth flue gas outlet (23) is communicated with an upper transverse collecting box (74) of the hearth flue gas outlet, and a communicating pipe (22) at the lower end of the hearth flue gas outlet (23) is communicated with the upper transverse collecting box (21) of the hearth rear wall; the upper end of the hearth upper part tapered section (124) is provided with a four-in-one water cooling ceiling (118) or a superheater ceiling (32), the front wall of the hearth upper part tapered section (124) is a hearth front wall film type water-cooled wall (4), the upper part of the rear wall of the hearth upper part tapered section (124) is provided with a hearth flue gas outlet (23), the middle lower part of the rear wall of the hearth upper part tapered section (124) is a hearth rear wall film type water-cooled wall forward upper bending inclined section (17), and two side walls of the hearth upper part tapered section (124) are hearth bilateral symmetrical film type water-cooled walls (9);

the upper end of the auxiliary combustion chamber (44) is provided with a two-return-stroke high-temperature accelerated descending tapered flue outlet (15) and a burnout chamber flue gas inlet (128), and the two-return-stroke high-temperature accelerated descending tapered flue outlet (15) is communicated with the burnout chamber flue gas inlet (128); the lower end of the auxiliary combustion chamber (44) is the upper end of the storage bin (11), the front wall of the auxiliary combustion chamber (44) is a hearth rear wall membrane type water-cooled wall (5), the rear wall of the auxiliary combustion chamber (44) is a vertical shaft flue front wall (45), and two side walls of the auxiliary combustion chamber (44) are three-in-one bilateral symmetry membrane type water-cooled walls (46);

the upper end of the burnout chamber (20) is a water-cooling ceiling or a superheater ceiling (32), the lower end of the burnout chamber (20) is provided with a burnout chamber flue gas inlet (128), the front wall of the burnout chamber (20) is a water-cooling wall (18) for guiding dust-containing flue gas to directly flush a storage bin, the rear wall of the burnout chamber (20) is a vertical shaft flue front wall (45), and two side walls of the burnout chamber (20) are three-in-one bilateral symmetrical membrane water-cooling walls (46);

the upper wall of the longitudinal wet steam cooling flue (96) at the upper part of the hearth is a water-cooling ceiling (100) of a boiler top flue, the lower wall high-temperature superheater (95) of the longitudinal wet steam cooling flue (96) at the upper part of the hearth abuts against the front three-return upward flue outlet (94) of the hearth, the rear three-return upward flue outlet (101) of the hearth and the vertical shaft flue inlet (103) are light pipe high-temperature superheaters, the high-temperature superheater (95) abuts against the top end of the hearth, the upper end of the front two-return high-temperature accelerated downward tapered flue (19) of the hearth and the upper end of the rear two-return high-temperature accelerated downward tapered flue (19) of the hearth are membrane wall high-temperature superheaters or light pipe high-temperature superheater cast refractory material seals (98), and two side walls of the longitudinal wet steam cooling flue (96) at the upper part of the hearth are bilateral symmetrical membrane walls (113).

3. A fluidized bed boiler with a water-cooled gas-solid separator and four and seven return water-cooled flues according to claim 1, characterized in that in the one return water-cooled ceiling (24), the two return water-cooled ceiling (29) and the superheater ceiling (32),

the rear upper end of the return water-cooling ceiling (24) is radially communicated with the upper transverse collecting box (28) of the hearth water-cooling ceiling, and the front end of the return water-cooling ceiling (24) is vertically bent downwards to extend to be communicated with the lower transverse collecting box (1) of the front wall of the hearth;

the front end of the two-return-stroke water-cooling ceiling (29) is radially communicated with the upper transverse collecting box (28) of the hearth water-cooling ceiling, and the rear end of the two-return-stroke water-cooling ceiling (29) vertically bends downwards to extend and is communicated with the lower transverse collecting box (16) of the guide dust-containing flue gas direct flushing bin;

the fluidized bed boiler with the water-cooling gas-solid separator and the four and seven return water-cooling flues further comprises a vertical shaft flue (41), wherein a superheater (43) or a reheater is arranged in the vertical shaft flue (41), and superheater ceilings (32) are arranged at the top end of the burnout chamber (20) and the top end of the vertical shaft flue (41); one end of the superheater ceiling (32) is communicated with the steam outlet (47), and the other end of the superheater ceiling (32) is communicated with a superheater or a reheater in the shaft flue (41).

4. A fluidized bed boiler with a water-cooled gas-solid separator and four and seven return water-cooled flues according to claim 1, characterized in that in the first return water-cooled ceiling (24), the second return water-cooled ceiling (29), the third return water-cooled ceiling (54) and the four return water-cooled ceiling (67),

the rear upper end of the return water-cooling ceiling (24) is radially communicated with the upper transverse collecting box (28) of the hearth water-cooling ceiling, and the front end of the return water-cooling ceiling (24) is vertically bent downwards to extend and is communicated with the lower transverse collecting box (60) of the hearth water-cooling ceiling;

the front end of the two-return-stroke water-cooling ceiling (29) is communicated with the upper transverse collecting box (28) of the hearth water-cooling ceiling in a radial direction, and the rear end of the two-return-stroke water-cooling ceiling (29) is vertically bent downwards to extend and is communicated with the lower transverse collecting box (62) of the two-return-stroke high-temperature accelerated descending tapered flue water-cooling ceiling;

the rear upper end of the three-return water-cooled ceiling (54) is radially communicated with the two-in-one water-cooled ceiling upper transverse collecting tank (56), and the front lower end of the three-return water-cooled ceiling (54) is communicated with the burnout chamber water-cooled ceiling lower transverse collecting tank (63);

the front upper end of the four-return water-cooling ceiling (67) is communicated with the upper transverse collecting box (28) of the hearth water-cooling ceiling, and the rear lower end of the four-return water-cooling ceiling (67) is communicated with the lower transverse collecting box (68) of the vertical shaft water-cooling ceiling.

5. The fluidized bed boiler with the cold water-solid separator and the four-and seven-return water-cooling flues as claimed in claim 1, wherein the fluidized bed boiler with the cold water-solid separator and the four-and seven-return water-cooling flues further comprises a water outlet (75), a gas collecting tank (76), an automatic exhaust valve (127), a steam outlet (47) and an economizer (48)),

the four-in-one water-cooling ceiling (118) is longitudinally arranged at the upper ends of a transverse collecting box (58) on the front wall of the hearth, a transverse collecting box (21) on the rear wall of the hearth, a transverse collecting box (61) on the water-cooling wall of a guide smoke direct-flushing storage bin, a transverse collecting box (37) on the front wall of the shaft and a transverse collecting box (69) on the rear wall of the shaft, the front end of the four-in-one water-cooling ceiling (118) is communicated with a transverse collecting box (72) on the front wall of the four-in-one water-cooling ceiling, the rear end of the four-in-one water-cooling ceiling (118) is communicated with a transverse collecting box (117) on the rear wall of the shaft, a gas collecting tank (76) is communicated with the upper center of the transverse collecting box (117) on the rear wall of the four-in-one water-cooling ceiling, exhaust pipes (126) are communicated with automatic exhaust valves (127), and a superheater (32) is longitudinally arranged on the front wall of the hearth, the transverse collecting box (58) on the upper end of the front wall of the hearth, the transverse collecting box (21) on the rear wall of the guide smoke direct-flushing storage bin, The vertical shaft front wall upper transverse collecting box (37) and the vertical shaft rear wall upper end of the transverse collecting box (69), the front end of the superheater ceiling (32) is communicated with the steam outlet (47), the rear end of the superheater ceiling (32) is communicated with the reheater, and the air guide pipe penetrates through the superheater ceiling (32) and is communicated with the air guide main pipe (33).

6. The fluidized bed boiler with the water-cooled gas-solid separator and the four-and seven-return water-cooled flues as claimed in claim 1, wherein the four-return water-cooled flues comprise a return hearth main combustion chamber (10) to a hearth flue gas outlet (23), a two-return high-temperature accelerated descending tapered flue (19), a three-return ascending flue and a boiler tail convection flue, the three-return ascending flue is a burnout chamber (20), the boiler tail convection flue is a vertical shaft flue (41), the seven-return water-cooled flues comprise a return hearth main combustion chamber (10) to a hearth flue gas outlet (23), a two-return high-temperature accelerated descending tapered flue (19) in the front of the hearth, a two-return high-temperature accelerated descending tapered flue (19) in the back of the hearth, a three-return ascending flue (20) in the front of the hearth, a three-return ascending flue (20) in the back of the hearth, a longitudinal wet water-vapor cold flue (96) in the upper part of the hearth and a boiler tail convection flue, the convection flue at the tail part of the boiler is a vertical shaft flue (41).

7. The fluidized bed boiler with the cold water-solid separator and the four-and seven-return water-cooling flues as claimed in claim 1, wherein the forced circulation tube rack type hot water boiler has a water path: the inlet water enters the coal economizer (48) from the water inlet (49), enters the vertical shaft rear wall transverse collecting tank (69) through the communicating pipe (22), is distributed to the vertical shaft flue rear wall (42) to move downwards to enter the vertical shaft rear wall lower transverse collecting tank (50), then enters the three-in-one bilateral symmetry lower longitudinal collecting tank (12) through the communicating pipe (22), enters the three-in-one bilateral symmetry membrane type water cooling wall (46) through the rear part of the partition plate (73), moves upwards to enter the rear part of the three-in-one bilateral symmetry upper longitudinal collecting tank (35), then forcibly enters the vertical shaft flue front wall (45) through the rear part of the partition plate (73), moves downwards to enter the vertical shaft front wall lower transverse collecting tank (51), then enters the bilateral symmetry lower longitudinal collecting tank (12) through the communicating pipe (22), and forcibly moves upwards to enter the middle part of the three-in-one bilateral symmetry upper longitudinal collecting tank (35) through the partition plate (73), forcibly enters a guide smoke direct-flushing bin water-cooled wall upper transverse collecting tank (61) through a partition plate (73), is forcibly distributed to a guide dust-containing smoke direct-flushing bin water-cooled wall (18) through the partition plate (73) to descend into a guide dust-containing smoke direct-flushing bin lower transverse collecting tank (16), then enters the front sections of the three-in-one bilateral symmetry lower longitudinal collecting tanks (12) through two-end communicating pipes (22), is forcibly distributed to a three-in-one bilateral symmetry membrane water-cooled wall (46) through the partition plate (73) to ascend into the front sections of the three-in-one bilateral symmetry upper longitudinal collecting tanks (35), enters the hearth bilateral symmetry upper longitudinal collecting tanks (27) through the communicating pipes (22), is forcibly distributed to a hearth rear wall upper transverse collecting tank (21) through the partition plate (73), is distributed to a hearth rear wall membrane water-cooled wall forward upper bending inclined section (17) and a hearth rear wall membrane water-cooled wall (5), the furnace hearth front wall film type water-cooling ceiling enters a furnace hearth rear wall lower transverse collecting tank (3) in a downward mode, enters a furnace hearth bilateral symmetry lower longitudinal collecting tank (2) and a furnace hearth front wall lower transverse collecting tank (1) through a communicating pipe (22), is forced to ascend to the upper end through a furnace hearth bilateral symmetry film type water-cooling wall (9) and a furnace hearth front wall film type water-cooling wall (4) respectively and enter a furnace hearth front wall upper transverse collecting tank (58) respectively, then enter a four-in-one water-cooling ceiling front transverse collecting tank (72) to be redistributed to a four-in-one water-cooling ceiling (118) through the communicating pipe (22), then enter a four-in-one water-cooling ceiling rear transverse collecting tank (117), and are sent to a heat supply system through a gas collecting tank (76) and a water outlet (75) in sequence.

8. The fluidized bed boiler with the four-return and seven-return water-cooling flues and the water-cooling solid separator as claimed in claim 6, wherein the upper end of the membrane water-cooling wall (4) on the front wall of the hearth of the main combustion chamber (10) of the hearth of the ultra-large power station boiler is bent backwards and upwards to be communicated with the upper transverse collecting box (58) on the front wall of the hearth, the communicating pipe (22) at the lower end of the flue gas outlet (23) of the hearth is communicated with the upper transverse collecting box (58) on the front wall of the hearth, and the communicating pipe (22) at the upper end of the flue gas outlet (23) of the hearth is communicated with the upper transverse collecting box on the front wall of the hearth; the upper end of a membrane water-cooled wall (5) on the rear wall of a hearth is bent forwards and upwards to be communicated with an upper transverse collecting box (21) on the rear wall of the hearth, a communicating pipe (22) at the lower end of a flue gas outlet (23) of the hearth is communicated with the upper transverse collecting box (21) on the rear wall of the hearth, the communicating pipe (22) at the upper end of the flue gas outlet (23) of the hearth is communicated with the upper transverse collecting box on the rear wall of the hearth to form a tapered section (124) on the upper part of the hearth, the upper end of a front three-pass upward flue of the hearth in a burnout chamber (20) of the ultra-large power station boiler is a front three-pass upward flue outlet (94) of the hearth, the front three-pass upward flue of the hearth refers to the upper part of the burnout chamber (20), the outlet (94) of the front three-pass upward flue of the hearth is a longitudinal wet-type water vapor cooling flue inlet at the top of the boiler, a high-temperature superheater (95) is arranged at the upper outlet (94) of the front three-pass upward flue of the hearth, and the lower end of the front three-pass upward flue of the hearth is a front three-pass upward flue gas return inlet (128) of the hearth, the front ends of the front three return-stroke ascending flues of the hearth are symmetrical vertical shaft flue rear walls (42), the rear ends of the front three return-stroke ascending flues of the hearth are guide dust-containing flue gas direct flushing bunker water cooling walls (18), and two side ends of the front three return-stroke ascending flues of the hearth are bilateral symmetrical membrane water cooling walls (113);

the upper end of the three-return-stroke ascending flue behind the hearth is provided with a three-return-stroke ascending flue outlet (101), the three-return-stroke ascending flue behind the hearth refers to the lower part of the burnout chamber (20), the three-return-stroke ascending flue outlet (101) behind the hearth is an inlet of a longitudinal wet water-vapor cooling flue at the top of the rear part of the boiler, a high-temperature superheater (95) is arranged at the position of the three-return-stroke ascending flue outlet (101) behind the hearth, the lower end of the three-return-stroke ascending flue behind the hearth is a three-return-stroke flue inlet (128) behind the hearth, the front end of the three-return-stroke ascending flue behind the hearth is a guide dust-containing flue direct-flushing bin water-cooling wall (18), the rear end of the three-return-stroke ascending flue behind the hearth is a vertical shaft flue front wall (45), and the two side ends of the three-return-stroke ascending flue behind the hearth are bilaterally symmetrical membrane water-cooling walls (113).

9. The fluidized bed boiler with the cold water-solid separator and the four-and seven-return water-cooling flues of the claim 8, wherein the flue of the ultra-large utility boiler is as follows: the flue gas enters two-return high-temperature accelerating descending reducing flue (19) which is symmetrical in the front and the back through two symmetrical hearth flue gas outlets (23) at the same time and is turned down at 180 degrees sharply, solid particles naturally settle in a bin (11) through the large expansion and deceleration of two-return high-temperature accelerating descending reducing flue outlets (15) which are symmetrical in the front and the back of the hearth, fine particles which do not settle in the bin (11) continue to burn in two symmetrical auxiliary combustion chambers (44) in the front and the back of the hearth, fly ash carried by the airflow enters two symmetrical burnout chambers (20) in the front and the back of the hearth, the burned flue gas which continues to burn out through the burnout chambers (20) enters a longitudinal wet-type water vapor cooling flue (96) at the upper part of the hearth through a front and a back symmetrical three-return ascending flue outlets (94) of the front and the back of the hearth and an ascending flue outlet (101) in the back of the hearth and then travels to the tail part to enter a vertical shaft flue (41), the flue gas enters a dust remover through a smoke outlet (129) by scouring and convection heat transfer with a superheater (43) and an economizer (48), is subjected to flue gas staticization and then is discharged to a chimney by a draught fan to enter the atmosphere;

the steam-water path of the ultra-large power station boiler comprises: inlet water enters the economizer (48) from a water inlet (49), the economizer (48) enters a flue water-cooling ceiling (100) at the top of the boiler through a communicating pipe (22), then enters a boiler barrel (26) through the communicating pipe (22), low-temperature water respectively enters a descending branch pipe through a descending main pipe (85), the low-temperature water respectively enters a lower longitudinal water-cooling branch pipe and a transverse collecting box and then enters a longitudinal water-cooling wall (108) and a transverse membrane water-cooling wall (108) to transfer heat through radiation convection through the descending branch pipe, hot water rises and respectively enters the upper longitudinal water-cooling box and the transverse collecting box, then respectively enters an air guide branch pipe through the air guide pipes of the upper longitudinal water-cooling box and the transverse collecting box and respectively enters the boiler barrel (26) through the air guide branch pipe, the low-temperature water continuously descends and circulates, and saturated steam enters a high-temperature superheater (95) and a superheater (43) through the communicating pipe (22) and is sent to a user through a steam outlet (47).

10. The fluidized bed boiler with the water-cooled gas-solid separator and the four-and seven-return water-cooled flues as claimed in claim 1, wherein the once-through boiler steam path of the four-return water-cooled flues comprises: inlet water enters the economizer (48) from the water inlet (49) and enters the transverse collecting tank (123) through the superheater communicating pipe (31), and then enters the lower longitudinal collecting tank (2) symmetrically arranged on two sides of the hearth, the lower transverse collecting tank (1) on the front wall of the hearth and the lower transverse collecting tank (3) on the rear wall of the hearth through the communicating pipe (22). The water of the symmetrical lower longitudinal header tanks (2) at the two sides of the hearth is distributed to the symmetrical membrane water walls (9) at the two sides of the hearth to ascend to the symmetrical upper longitudinal header tanks (27) at the two sides of the hearth and then all the backwardly moving partition plates (73) at the symmetrical lower transverse header tanks (12) at the two sides of the three-in-one and then all the backwardly moving partition plates start to descend to the symmetrical lower transverse header tanks (12) at the two sides of the three-in-one and then all the backwardly moving partition plates start to move backwardly to the rear end to be communicated with the vertical shaft rear wall lower transverse header tank (50) through the communicating pipe (22), part of superheated steam is distributed to the vertical shaft flue rear wall (42) through the vertical shaft rear wall lower transverse header tank (50) and ascends to the vertical shaft rear upper transverse header tank (69) and then is communicated with the transverse superheater header tank (79) through the communicating pipe (31), enters a superheater (43) through a two-way communicating pipe (22) and descends to be sent to required equipment through a steam outlet (47).

Water in the lower transverse collecting tank (1) on the front wall of the hearth and the lower transverse collecting tank (3) on the rear wall of the hearth is respectively distributed to the film-type water-cooled wall (4) on the front wall of the hearth and the film-type water-cooled wall (5) on the rear wall of the hearth and then respectively rises to the upper transverse collecting tank (58) on the front wall of the hearth and the upper transverse collecting tank (21) on the rear wall of the hearth; an upper transverse header (58) on the front wall of the hearth is communicated with a superheater ceiling header (79) through a communicating pipe (22); an upper transverse header (21) on the rear wall of the hearth is communicated with a superheater ceiling header (79) through a communicating pipe (22); two paths of water of a front collecting box and a rear collecting box of a hearth enter a superheater ceiling (122) through a communicating pipe (22) and then enter a transverse collecting box (79), the superheater transverse collecting box (79) is communicated with an upper transverse collecting box (61) of a guide smoke direct flushing bin through a superheater communicating pipe (31), the water is distributed to a tube bundle of the guide smoke direct flushing bin and then enters a lower transverse collecting box (16), the lower transverse collecting box (16) is communicated with a transverse collecting box (89) on a front wall of the bin through the communicating pipe (22), the transverse collecting box (89) on the front wall of the bin is distributed to a membrane water-cooled wall (91) on the front wall of the bin and then enters a lower transverse collecting box (93) on the front wall of the bin, then is communicated with a lower transverse collecting box (92) on a rear wall of the bin through the superheater communicating pipe (31) and distributed to a membrane water-cooled wall (90) on the rear wall of the bin, then enters a transverse collecting box (87) on the rear wall of the bin and then is communicated with a vertical shaft lower transverse collecting box (51) through the communicating pipe (22), the lower transverse collecting box (51) of the vertical shaft front wall is distributed to the front wall (45) of the vertical shaft flue, then the lower transverse collecting box ascends into the upper transverse collecting box (37) of the vertical shaft front wall and is communicated with a superheater collecting box (79) through a superheater communicating pipe (31), the superheater collecting box (79) is distributed to a superheater (43), and then the lower transverse collecting box descends through a steam outlet (47) and is sent to required equipment.

11. The fluidized bed boiler with the cold water-solid separator and the four-and seven-return water-cooling flues as claimed in claim 1, wherein the water vapor path of the seven-return water-cooling flue ultra-large power station direct-flow boiler is as follows: inlet water enters the economizer (48) from the water inlet (49) and enters the transverse collecting tank (123) through the superheater communicating pipe (31), and then enters the lower longitudinal collecting tank (2) symmetrically arranged on two sides of the hearth, the lower transverse collecting tank (1) on the front wall of the hearth and the lower transverse collecting tank (3) on the rear wall of the hearth through the communicating pipe (22). The water distribution of the symmetrical lower longitudinal header (2) at the two sides of the hearth is distributed to the symmetrical membrane water walls (9) at the two sides of the hearth to ascend to the symmetrical upper longitudinal header (99) at the two middle sides and move forward to the partition plate (73) to be distributed to the symmetrical membrane water walls (46) at the two sides of the three-in-one to descend to the symmetrical lower longitudinal header (104) at the two sides of the three-in-one, then to the symmetrical upper longitudinal header (35) at the two sides of the three-in-one to move forward to be distributed to the symmetrical membrane water walls (46) at the two sides of the three-in-one to ascend to the symmetrical upper longitudinal header (12) at the two sides of the three-in-one to move backward to the symmetrical upper longitudinal header (35) at the two sides and then to be distributed to the symmetrical upper longitudinal header (46) at the two sides of the three-in-one to the partition plate (73) to be distributed to the symmetrical water walls (46) at the two sides of the three-in-one to move backward to be distributed to the symmetrical upper longitudinal header (35) at the two sides of the two sides and distributed to the superheater (43) to move downward to be distributed to the three-in-one by communicating pipe (31) and distributed to the superheater (79) at the three-in-one sides of the three-one sides A steam outlet (47).

Water in the lower transverse collecting box (1) on the front wall of the hearth and the lower transverse collecting box (3) on the rear wall of the hearth is respectively distributed to the membrane type water-cooled wall (4) on the front wall of the hearth, the membrane type water-cooled wall (5) on the rear wall of the hearth and the membrane type water-cooled wall (108) to rise to the upper transverse collecting box (21) on the front wall of the hearth and the upper transverse collecting box on the rear wall of the hearth; the device is communicated with a rear transverse collecting box (79) of a superheater ceiling through a superheater communicating pipe (31) and is distributed to a three-in-one superheater ceiling (119) to move forwards to enter a front transverse collecting box (79) of the superheater ceiling, and then is communicated with an upper transverse collecting box (61) of a guide smoke direct flushing bunker through a communicating pipe (22) and is distributed to a water-cooled wall (18) of the guide dust-containing smoke direct flushing bunker to move downwards to enter a lower transverse collecting box (16) of the guide smoke direct flushing bunker and then is communicated with a transverse collecting box (87) on a bunker rear wall through the communicating pipe (22); the horizontal collecting box (87) on the rear wall of the storage bin is communicated with a symmetrical horizontal collecting box (50) through a superheater communicating pipe (31) and is distributed to a rear wall of a shaft flue and a symmetrical front wall (42) of a double-hearth to go upwards to enter the rear wall of the shaft through the symmetrical horizontal collecting box (69) and then is communicated with the horizontal collecting box (79) of the ceiling of the superheater through a communicating pipe (22) and is distributed to a ceiling of a three-in-one superheater (119) and then goes into the horizontal collecting box (79) behind the ceiling of the superheater, then is communicated with the upper horizontal collecting box (61) of a guide smoke direct flushing storage bin through the superheater communicating pipe (31) and is distributed to the water cooling wall (18) of the guide smoke direct flushing storage bin to go downwards to the lower horizontal collecting box (16) of the guide smoke direct flushing storage bin, the lower horizontal collecting box (16) of the storage bin is communicated with the horizontal collecting box (89) on the front wall of the storage bin through the communicating pipe (22), and is respectively communicated with the lower horizontal collecting box (51) of the front wall of the shaft through the communicating pipe (31) and the lower horizontal collecting box (50) and is distributed to the front wall (45) of the flue and the rear wall (42) The upward flows respectively enter a horizontal collecting box (37) on the front wall of the vertical shaft and a horizontal collecting box (69) on the rear wall of the vertical shaft, and are respectively communicated with a horizontal collecting box (79) of the superheater through a superheater communicating pipe (31) and then descend to a steam outlet (47).

12. The upper furnace tapered section of a fluidized bed boiler with four-return and seven-return water-cooling flues and a water-cooling gas-solid separator as claimed in claim 1, wherein the rear wall of the upper furnace tapered section (124) of the four-return water-cooling flue is the forward bending point (14) of the membrane water-cooling wall of the rear wall of the furnace to the top end, the front wall of the upper furnace tapered section (124) of the four-return water-cooling flue is the front wall of the furnace, and the two side walls of the upper furnace tapered section (124) of the four-return water-cooling flue at the forward bending point of the membrane water-cooling wall of the rear wall of the furnace are the symmetrical membrane water-cooling walls (9) at two sides of the furnace; the front wall of the reducing section (125) at the upper part of the hearth of the seven-return water-cooling flue is the forward bending point (14) of the membrane water-cooling wall at the rear wall of the hearth to the top end, and the rear wall of the reducing section (125) at the upper part of the hearth of the seven-return water-cooling flue is the forward bending point (14) of the membrane water-cooling wall at the rear wall of the hearth to the top end.

13. The fluidized bed boiler with the cold water solid separator and the four-and seven-return water-cooling flues as claimed in claim 1, wherein pipe through holes correspondingly matched with the steam guide pipe and the exhaust pipe are reserved on each water-cooling ceiling and each superheater ceiling of the fluidized bed boiler with the cold water solid separator and the four-and seven-return water-cooling flues, and the boiler barrel can be arranged at the front end and the rear end of the top end of the boiler body and at any position which is favorable for arranging a descending pipe in the longitudinal direction.