CN111349463A

CN111349463A - Entrained-flow bed gasification system and method for dry pulverized coal

Info

Publication number: CN111349463A
Application number: CN201811585208.9A
Authority: CN
Inventors: 刘臻; 方薪晖; 彭宝仔; 冯子洋; 索娅; 安海泉; 李烨
Original assignee: China Energy Investment Corp Ltd; National Institute of Clean and Low Carbon Energy
Current assignee: China Energy Investment Corp Ltd; National Institute of Clean and Low Carbon Energy
Priority date: 2018-12-24
Filing date: 2018-12-24
Publication date: 2020-06-30
Anticipated expiration: 2038-12-24
Also published as: CN111349463B

Abstract

The invention relates to the technical field of coal gasification, and discloses an entrained flow bed gasification system and method for dry coal powder. The system comprises: the system comprises a material conveying unit (1), a gasification unit (2) and a steam unit (4); the gasification unit (2) comprises a flat flame type gasification burner (21), a gasification chamber (22), a first heat exchange unit (23) and a slag collecting chamber (24) which are sequentially communicated, and the first heat exchange unit (23) is communicated with the steam unit (4); the flat-flame type gasification burner (21) comprises a burner unit (25) arranged at the top of the gasification unit (2), the flat-flame type gasification burner (21) enables a gasification agent and dry coal powder to collide in the gasification chamber (22) and be ignited to form flat flame, and the number of the burner units (25) is more than or equal to 3. When the system is used for the entrained flow gasification process of dry pulverized coal, the thermal efficiency of the system can be obviously improved, and the specific oxygen consumption and the specific coal consumption are reduced.

Description

Entrained-flow bed gasification system and method for dry pulverized coal

Technical Field

The invention relates to the technical field of coal gasification, in particular to an entrained flow bed gasification system and method for dry pulverized coal.

Background

Energy is an important basis for human survival and development, and the energy structure of 'lack of oil and gas' forces China to consume huge cost to purchase a large amount of gas-liquid fuel abroad every year so as to meet the development requirements of domestic economy and society, so that the energy safety of China is difficult to guarantee, on the other hand, China is a relative 'coal-rich' country, the coal exploration reserve of China already accounts for 13.3% of the global exploration reserve, and the unique energy structure determines the country which consumes coal as the main energy of China. Coal gasification is taken as a key technology and a common technology for green, efficient and clean conversion of coal, and the development of the technology plays a crucial role in economic development of China. Coal gasification refers to the gasification reaction of coal and gasifying agent to generate CO and H under a certain temperature and pressure₂The process of (1).

CN107033968A discloses an entrained flow gasification system and a gasification method, wherein the entrained flow gasification system comprises: the gasification furnace comprises a gasification furnace and a radiation waste boiler, the gasification furnace is provided with a feed inlet and an oxygen inlet, and the radiation waste boiler is provided with a first water inlet, a first steam outlet, a crude gas outlet and a slag outlet; the steam drum is provided with a first water outlet, a first steam inlet and a steam discharge port, the first water outlet is communicated with the first water inlet so as to exchange heat with the radiation waste boiler through water in the steam drum, and the first steam inlet is communicated with the first steam outlet; and the gas washing tower is provided with a crude gas inlet and a crude gas discharge port, and the crude gas inlet is communicated with the crude gas outlet so that the gas washing tower washes the crude gas discharged by the gasification furnace. The entrained flow bed gasification system adopts the radiation waste boiler and the gas washing tower to fully recover the sensible heat of coal gas in the coal gasification process, so that the energy utilization is more sufficient. However, the system also has several problems: (1) the crude gas generated by the system directly enters a convection waste boiler or a gas washing tower after passing through a radiation waste boiler. Because the raw gas generated by the gasification reaction contains a large amount of fly ash, blockage or increase of the burden of downstream equipment can be easily caused without primary dust removal, so that the system is easy to operate unstably; (2) the system does not describe the state of the fed material (dry powder or coal slurry) and the characteristics of the burner, in this case coal slurry or dry powder is generally understood, and the burner is a single burner. However, because the single burner, especially the coal water slurry single burner, has slow gasification reaction speed, long reaction residence time and small generated heat flux, if the system is adopted, the equipment investment and the operation cost are increased, and the applicability is not strong.

CN106753569A discloses a low-pressure dry pulverized coal gasification process, which comprises the steps of feeding pulverized coal into a gasification furnace for gasification to obtain synthesis gas, chilling the synthesis gas by lower-section water of the gasification furnace, feeding the synthesis gas into a washing tower for washing, discharging the synthesis gas from the top of the washing tower, and feeding the synthesis gas into a subsequent process, wherein a mixture of the pulverized coal and oxygen is sprayed into the gasification furnace through a vertical nozzle at the top of the gasification furnace and a plurality of lateral nozzles on the side wall of the upper section of the gasification furnace and is instantly ignited, formed flames are in a confluent state, and the pulverized coal is gasified at high temperature to generate synthesis gas; the synthetic gas enters a right-angle elbow in the washing tower through the air inlet, the synthetic gas is fully mixed with water mist sprayed by the blocking spray head at the outlet of the right-angle elbow and is cooled, the unaeromized water flows into the lower section of the washing tower along a drain pipe at the bottom of the right-angle elbow, and the washed synthetic gas is discharged from the top of the washing tower. The process is mainly characterized in that the gasification efficiency is improved by an overhead vertical nozzle and a plurality of lateral nozzles on the side wall of the upper section. However, the process is simple, but the thermal efficiency is not high because the process employs water chilling to chill and deashing the raw synthesis gas.

CN104498101B discloses a coal gasification device and a process; the system comprises a coal gasification generating system, a circulating gas system, a circulating water system and a heat energy recovery and steam generating system, wherein the coal gasification generating system comprises a gasification furnace, a cyclone separator connected with the gasification furnace, a plurality of waste heat boilers connected with the cyclone separator and a water washing tower connected with the waste heat boilers; the circulating gas system comprises a circulating gas compressor, one end of the circulating gas compressor is connected with a synthetic gas outlet pipeline of the water washing tower, and the other end of the circulating gas compressor is connected with a chilling ring inside the gasification furnace. The process is mainly characterized in that a plurality of nozzles are arranged at the top for feeding, the high-temperature crude synthesis gas generated after gasification is subjected to compression chilling by using circulating gas after a water washing tower, and then is subjected to dust removal by a cyclone separator and exchanges heat with a plurality of waste heat boilers. But the adoption of the recycle gas for chilling needs compression, thereby increasing the energy consumption of the system; and then the waste heat boiler is connected with a plurality of waste heat boilers for heat exchange, so that the equipment investment and the operation cost are increased.

Disclosure of Invention

The invention aims to solve the problems of poor coal type adaptability, low heat utilization efficiency of a gasification system, low heat value of generated coal gas and the like in the prior art, and provides an entrained flow bed gasification system and a method for gasifying dry coal powder by using the same.

The inventor of the invention invents an entrained flow gasification system and a method of dry pulverized coal by research, the system adopts a flat flame type gasification burner, the used flat flame type gasification burner comprises a plurality of burner units, each burner unit mixes a gasification agent with the dry pulverized coal from a material conveying unit by collision and ignites the mixture, and the number of the burner units is more than or equal to 3. Because set up a plurality of nozzle units in flat flame type gasification nozzle, compare with the gasification unit including a plurality of nozzles in the prior art, the tiling arrangement mode of a plurality of nozzle units makes gasification process have characteristics such as gasification reaction rate is fast, flame is short, reaction dwell time is short, the process heat is high, so can show improvement coal type adaptability.

When the flat flame type gasification burner is used in the entrained flow gasification system of the dry coal powder, the dry coal powder passes through the flat flame type gasification burner and is mixed with a gasification agent in a gasification chamber to generate high-temperature crude synthesis gas and molten slag through gasification reaction, the high-temperature crude synthesis gas is subjected to heat exchange and cooling through a heat exchange unit to generate a byproduct steam, the byproduct steam enters a steam unit, the residual steam is output to other downstream processes except for the requirement of the flat flame type entrained flow gasification system, the generated coal gas has high heat value, the heat efficiency of the system can be obviously improved, and the specific oxygen consumption and the specific coal consumption are reduced.

In order to achieve the above object, a first aspect of the present invention provides an entrained flow gasification system for dry pulverized coal, comprising:

the gasification unit comprises a flat flame type gasification burner, a gasification chamber and a first heat exchange unit which are arranged from top to bottom in sequence; the flat flame type gasification burner introduces a gasification agent and dry coal powder into the gasification chamber, and the dry coal powder and the gasification agent are subjected to gasification reaction in the gasification chamber to generate crude synthesis gas and molten slag; the first heat exchange unit carries out heat exchange and temperature reduction on the crude synthesis gas and the slag to obtain a first crude synthesis gas and the cooled slag, and a byproduct of steam;

the steam unit is communicated with the water inlet and the water outlet of the first heat exchange unit and can perform centralized treatment and distribution on the water inlet of the first heat exchange unit and the byproduct steam;

the flat flame type gasification burner comprises a plurality of burner units arranged at the top of the gasification unit, the flat flame type gasification burner enables a gasification agent and dry coal powder to collide in the gasification chamber and be ignited to form flat flame, and the number of the burner units is more than or equal to 3.

In a second aspect, the present invention provides a method for dry coal fines gasification in a system according to the first aspect of the invention, the method comprising:

s1, respectively introducing a gasifying agent and dry coal powder into a gasification unit through a flat flame type gasification burner, enabling the gasifying agent and the dry coal powder to collide in a gasification chamber of the gasification unit and ignite to form flat flame, and enabling the gasifying agent and the dry coal powder to generate gasification reaction to generate crude synthesis gas and molten slag;

s2, cooling the crude synthesis gas and the slag in the first heat exchange unit to obtain a first crude synthesis gas and the cooled slag, and generating steam as a byproduct;

and S3, collecting the steam by-produced in the step S2 and the heat exchange medium used for heat exchange, and carrying out centralized treatment and distribution.

Through the technical scheme, the technical scheme provided by the invention has the following advantages:

I. the flat flame type gasification burner has the characteristics of high gasification reaction speed, short flame, short reaction retention time, high process heat and the like, so that the adaptability of coal types can be obviously improved;

II, because the flame length and the reaction residence time are both short, the requirement on gasification reaction space is low, thereby reducing the overall investment and the operation cost of the whole system;

and III, multiple heat exchange is adopted, so that the heat utilization efficiency of the system can be effectively improved.

Drawings

FIG. 1 is a schematic flow diagram of one embodiment of the present invention;

FIG. 2 is a schematic view of a flat flame type gasification burner incorporating a distributor according to the present invention;

FIG. 3 is a schematic view of a flat flame type gasification burner in accordance with the present invention;

FIG. 4 is a top view of a burner unit according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of the impingement of a burner unit of one embodiment of the present invention;

FIG. 6 is a schematic view of one embodiment of a unified feed for burner units according to the present invention;

FIG. 7 is a schematic view of an embodiment of the burner unit of the present invention fed independently;

FIG. 8 is a schematic view of the structure of a dispenser according to an embodiment of the present invention;

FIG. 9 is a cross-sectional view of a dispenser according to an embodiment of the present invention;

FIG. 10 is a cross-sectional view taken along D-D of FIG. 9;

FIG. 11 is a partial view of the structure of a dispenser according to an embodiment of the present invention;

FIG. 12 is a schematic structural view of a dispensing can according to an embodiment of the invention;

fig. 13 is a schematic structural view of a dispensing can according to another embodiment of the present invention.

Description of the reference numerals

1. Material conveying unit 2, gasification unit 4 and steam unit

5. Slag water treatment unit 6, washing unit 7 and wastewater treatment unit

8. Dust removal unit 11, storage bin 12 and pulverized coal locking bucket

20 material-sending tank 21, flat flame type gasification burner 22 and gasification chamber

23. First heat exchange unit 24, slag collecting chamber 25 and burner nozzle unit

30. Dry coal powder distributing and conveying pipeline 100, distributor 110 and main pipe

111. A feed inlet 112, a discharge outlet 113 and a contraction section

114. Constant cross section segment 115, expanding segment 120, cover plate

121. Distribution hole 122, distribution portion 130, purge tube

131. Purge chamber 132, purge gas inlet 133, filter layer

140. Distribution member 150, partition 210, and can

211. Containing chamber 212, dry coal powder chamber 213, fluidizing chamber

214. Air inlet 220, fluidization plate 221, upper surface

222. Conical section 223, cylindrical section 230, discharge tube

231. Horizontal segment 232, transition segment 233 and vertical segment

240. Material distributing boss

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

As previously mentioned, a first aspect of the present invention provides an entrained flow gasification system for dry coal fines, the system comprising:

the gasification unit 2 comprises a flat flame type gasification burner 21, a gasification chamber 22 and a first heat exchange unit 23 which are arranged from top to bottom in sequence; the flat flame type gasification burner 21 introduces a gasification agent and dry coal powder into the gasification chamber 22, and the dry coal powder and the gasification agent are subjected to gasification reaction in the gasification chamber 22 to generate crude synthesis gas and molten slag; the first heat exchange unit 23 is used for carrying out heat exchange and cooling on the crude synthesis gas and the slag to obtain a first crude synthesis gas and cooled slag and byproduct steam;

the steam unit 4 is communicated with the water inlet and the water outlet of the first heat exchange unit 23 and can perform centralized treatment and distribution on the water inlet of the first heat exchange unit 23 and the byproduct steam;

the flat flame type gasification burner 21 comprises a burner unit 25 arranged at the top of the gasification unit 2, the flat flame type gasification burner 21 enables a gasification agent and dry coal powder to collide in the gasification chamber 22 and be ignited to form flat flame, and the number of the burner units 25 is more than or equal to 3.

According to the invention, the flat flame type burner 21 can realize the collision and mixing of the dry coal powder and the gasifying agent outside the port of the burner unit 25, the formed collision points are substantially positioned on the same plane, the number of clusters of the flames formed after the collision and ignition is equal to the number of the burner units 25, and the flames of each cluster are parallel to each other, namely the flat flames are formed. Specifically, the flat flame formation may be achieved by controlling a distance CP of the impact point from the end surface of the flat flame type gasification burner 21 and a distance OC of the flow of the gasification agent to the flow of the dry pulverized coal at the end surface of the burner unit 25.

In the present invention, preferably, the burner unit 25 includes at least one dry coal powder channel and at least one gasifying agent channel, and a distance CP between an impact point of the dry coal powder flow and the gasifying agent flow and an end surface of the burner unit 25 is 1.0 to 10 times, preferably 3 to 6 times, a distance OC between the gasifying agent flow and the dry coal powder flow at the end surface of the burner unit 25.

As shown in fig. 4 and 5, the dry coal powder channel is arranged in the center of the burner unit 25, and 3 gasifying agent channels are arranged around the dry coal powder channel, and the distance OC from the gasifying agent flow to the dry coal powder flow at the end surface of the burner unit 25 refers to the distance from the intersection point of the center line and the end surface of the dry coal powder channel to the intersection point of the center line and the end surface of the gasifying agent channel.

According to one embodiment of the present invention, the dry coal powder channel and the gasifying agent channel are designed to be coaxial, for example, the gasifying agent channel is arranged at the center of the burner unit 25, the dry coal powder channel is an annular channel enclosing the gasifying agent channel at the center, the gasifying agent flow is ejected vertically and downwards, and the annular dry coal powder fluid can be ejected inwards and downwards, for example, in an inverted cone fluid surface, and forms impact with the gasifying agent flow at point P, so as to achieve the purposes of gas-solid mixing and gasification combustion. At this time, the distance OC between the gasification agent flow and the pulverized coal flow at the end face of the burner refers to the distance from the middle line between the inner ring and the outer ring of the annular channel at the end face of the burner to the central line of the gasification agent channel.

An entrained flow gasification system for dry pulverized coal provided in a first aspect of the present invention is described in detail below with reference to fig. 1 to 7.

As shown in FIG. 1, according to a preferred embodiment of the present invention, the entrained flow gasification system includes

The system comprises a material conveying unit 1, a gasification unit 2, a steam unit 4, a slag water treatment unit 5, a washing unit 6 and a wastewater treatment unit 7.

The gasification unit 2 comprises a flat flame type gasification burner 21, a gasification chamber 22, a first heat exchange unit 23 and a slag collecting chamber 24 which are arranged from top to bottom in sequence. Specifically, the gasification agent from the gasification agent pipeline and the dry coal powder from the material conveying unit 1 are collided and mixed outside the port of the burner unit 25, and gasification reaction is carried out in the gasification chamber 22, so that products such as crude synthesis gas and slag are produced. The product stream leaves the gasification chamber 22 in a downward direction, and primary heat exchange, such as water-cooling heat exchange and radiation waste boiler heat exchange, is performed in the first heat exchange unit 23 to obtain a first crude synthesis gas and cooled slag, and meanwhile, steam is byproduct in the first heat exchange unit 23.

Preferably, the temperature of the first crude synthesis gas is 600-750 ℃, and the pressure of the byproduct steam of the first heat exchange unit 23 is 3.3-5 MPa.

According to the present invention, the molten slag preferably descends and is chilled to form solid slag in the slag trap 24.

In the present invention, the term "impingement mixing" refers to that the dry coal powder and the gasifying agent enter the burner unit 25 through different pipelines, and impinge and mix outside the port of the burner unit 25, that is, the dry coal powder and the gasifying agent do not enter the burner unit 25 after mixing, and there is no mixing of the dry coal powder and the gasifying agent in any form in the burner unit 25.

According to the invention, the scrubbing unit 6 is adapted to scrub the first raw synthesis gas to obtain clean synthesis gas and grey water. Preferably, the washing unit 6 is a tray washing device.

The slag water processing unit 5 is communicated with the slag collecting chamber 24 of the gasification unit 2 to process solid slag and slag water from the slag collecting chamber 24.

The waste water treatment unit 7 is communicated with the washing unit 6 and the slag water treatment unit 5, and is used for purifying the grey water from the washing unit 6 and the slag water from the slag water treatment unit 5 to obtain washing water, and returning the washing water to the washing unit 6 for washing. The wastewater treatment unit 7 can be the existing equipment for treating the coal chemical industry wastewater, as long as the requirement that the solid content of the wastewater is less than 200mg/L can be met.

It can be understood that, according to a preferred embodiment of the present invention, the slag chamber 24, the slag water treatment unit 5, the waste water treatment unit 7 and the scrubbing unit 6 together form a water circulation loop, that is, the chilling water becomes slag water after chilling the slag, the slag water becomes clean scrubbing water after treating the waste water, the scrubbing water becomes grey water after scrubbing and dedusting the first raw syngas, at least part of the grey water is directly introduced into the slag chamber 24 of the gasification unit 2 as chilling water to chill the slag, and the rest of the grey water can be sent to the waste water treatment unit 7 for treatment and then returned to the scrubbing unit 6 for recycling. Therefore, the invention can finish the chilling and washing of the crude synthesis gas under the condition of not additionally introducing chilling water and/or washing water, does not need to discharge waste water, and is beneficial to reducing the cost of waste water treatment.

The steam unit 4 is communicated with the water-cooled wall of the gasification chamber 22 and the water inlet (or steam inlet) and the water outlet (or steam outlet) of the first heat exchange unit 23, and is used for centralized treatment and distribution of the respective cooling media (water) of the gasification chamber 22 and the first heat exchange unit 23 and the byproduct steam, and the redundant steam can be used by the system or downstream processes.

In the present invention, the lining of the gasification chamber 22 may be refractory bricks and/or a water wall, preferably the water wall is a coil or tube array structure, and more preferably the water wall is a membrane water wall of a tube array structure.

According to a preferred embodiment of the present invention, the inner wall of the gasification chamber 22 is provided with a membrane water wall, the water outlet (or steam outlet) of which is connected to the water inlet (or steam inlet) of the steam unit 4, and the water inlet (or steam inlet) of which is connected to the water outlet (or steam outlet) of the steam unit 4, so that the heat carried by the circulating medium (such as steam) in the membrane water wall can be absorbed by the steam unit 4.

Similarly, the water inlet (or steam inlet) of the first heat exchange unit 23 is communicated to the water outlet (or steam outlet) of the steam unit 4, and the water outlet (or steam outlet) is communicated with the water inlet (or steam inlet) of the steam unit 4, so that the steam unit 4 can absorb heat carried by the medium (e.g. steam) discharged by the first heat exchange unit 23. The residual steam of the steam unit 4 can be used for heat tracing, pipeline heat preservation, gasifying agent and the like in the system or can be conveyed out of the system for downstream processes, such as power generation of a steam turbine of a power plant and the like.

Preferably, a dust removal unit 8 is provided between the gasification unit 2 and the washing unit 6. Further preferably, the dust removal unit 8 is communicated with the first heat exchange unit 23, so that the raw synthesis gas leaving the gasification unit 2 enters the washing unit 6 for washing after being subjected to dust removal by the dust removal unit 8.

Preferably, the dust removing unit 8 is a high-temperature cyclone dust remover, a high-temperature filter medium dust remover or a combined dust remover thereof, and the high-temperature filter medium can be a high-temperature resistant ceramic filter element, a metal filter element or a mixed filter element thereof.

As shown in fig. 2 and 3, according to a preferred embodiment of the present invention, the flat flame type gasification burner 21 includes a plurality of burner units 25 arranged parallel to the central axis of the gasification unit 2.

Each burner unit 25 is provided with a dry coal powder channel, which can be located at the center or arranged around the gasification agent channel, i.e. the coal powder stream is enclosed by the gasification agent airflow or the gasification agent stream is enclosed by the coal powder stream. For example, the burner unit 25 includes: a dry coal powder channel and a plurality of gasifying agent channels arranged around the dry coal powder channel; or a gasifying agent channel and a plurality of dry coal powder channels arranged around the gasifying agent channel. The dry coal powder passage and the gasifying agent passage may be coaxially provided, for example, the burner unit 25 includes: a dry pulverized coal passage provided in the center of the burner unit 25 and an annular gasifying agent passage provided around the dry pulverized coal passage; or a gasifying agent passage arranged at the center of the burner unit 25 and an annular dry coal powder passage arranged around the gasifying agent passage. However, in any arrangement, it is necessary that each of the burner units 25 can collide the dry coal powder and the gasifying agent at a certain distance outside the end surface of the burner unit 25 and burn the dry coal powder and the gasifying agent, so that the collision points of the dry coal powder and the gasifying agent of each of the burner units 25 are substantially located on the same plane to form the flat flame.

To better achieve the above object, as shown in fig. 4 and 5, the forming of the flat flame preferably includes controlling an angle α between the center lines of the dry pulverized coal passage and the gasifying agent passage in the burner unit 25 to be greater than 0 degrees to less than 90 degrees, preferably 15 degrees to 45 degrees, and most preferably 30 degrees, and more preferably, the velocity of the gasifying agent flow at the outlet of the burner unit 25 is 2 to 10 times the velocity of the dry pulverized coal.

According to the invention, the number of clusters of the flames formed after collision and ignition is equal to that of the burner units 25 by adopting the system provided by the invention, and the flames of each cluster are parallel to each other, the length of each flame is 5-30 times, preferably 7-15 times, that of CP, and the diameter of each flame is about 2-3 times, preferably 2 times, that of OC. Compared with the multi-nozzle material flow collision type gasification technology in the prior art, the flat flame type gasification technology has the characteristics of high gasification reaction speed, short flame, short reaction residence time, high process heat and the like, so that the coal adaptability can be obviously improved, and moreover, because the flame length and the reaction residence time are both short, the requirement on gasification reaction space is low, so that the overall investment and the operation cost of the whole system are reduced.

According to the present invention, it is preferable that the number of the burner units 25 is 3 to 10.

As shown in fig. 2, according to a preferred embodiment of the present invention, a distributor 100 may be further included in the flat-flame gasification burner 21. Specifically, a dry pulverized coal (as shown in fig. 6) from the material conveying unit 1 is uniformly divided into a plurality of streams by the distributor 100, and the streams are respectively conveyed to the corresponding burner units 25. That is, one-half of the dry pulverized coal is completed in the flat-flame type gasification burner 21.

The dispenser 100 according to the present invention will be described in detail with reference to fig. 8 to 11.

As shown in fig. 8, according to a preferred embodiment of the present invention, the dispenser 100 includes a main pipe 110 and a cover plate 120. The main pipe 110 has a feed port 111 and a discharge port 112. The cover plate 120 is disposed on the main pipe 110, and the cover plate 120 covers the discharge hole 112. The cover plate 120 is provided with a plurality of distribution holes 121, and the plurality of distribution holes 121 are communicated with the plurality of dry pulverized coal channels in a one-to-one correspondence manner. In other words, the number of distribution holes 121 is equal to the number of dry coal powder passages, and one distribution hole 121 communicates with one dry coal powder passage.

The dry pulverized coal passage and the gasifying agent passage may constitute one burner unit 25, and therefore the flat-flame gasification burner 21 of the present invention has a plurality of the burner units 25, that is, the flat-flame gasification burner 21 of the present invention can integrate a plurality of the burner units 25.

Compared with the prior art with a single burner, the flat flame type gasification burner 21 provided by the invention integrates a plurality of burner units 25, so that the flame length can be reduced, and the temperature is more uniformly distributed near the flat flame type gasification burner 21. This reduces the peak temperature value, and thus prolongs the service life of the flat-flame gasification burner 21.

Because the included angle between each gasifying agent channel and the corresponding dry coal powder channel is more than 15 degrees and less than 45 degrees, each gasifying agent channel is neither perpendicular to nor parallel to the corresponding dry coal powder channel. The oxygen-containing gasifying agent injected from each gasifying agent passage and the dry pulverized coal injected from the corresponding dry pulverized coal passage collide with each other below the flat-flame type gasification burner 21 (when the flat-flame type gasification burner 21 is mounted on the gasification chamber), so that the oxygen-containing gasifying agent and the dry pulverized coal can be mixed more quickly and uniformly, and the gasification reaction rate can be increased.

Tests prove that by controlling the distance CP from the impact point to the end face of the burner unit 25, the distance OC from the gasifying agent flow to the dry pulverized coal flow and the speeds of the gasifying agent flow and the dry pulverized coal flow, the width and the length of flame which is combusted downwards after the gasifying agent flow and the dry pulverized coal flow collide can be adjusted, slag adhering is ensured, and meanwhile, the inner wall of a gasification chamber is prevented from being damaged by explosive flame. The flame cluster formed by fully mixing the multiple gasification agent flows and the dry pulverized coal flows downwards while burning, so that the gasification agent flows in each flame burn more fully, and the reaction rate is obviously improved.

Because the gasifying agent channel is positioned in the dry coal powder channel, a feeding mode of coal-in-gas can be formed. The feeding mode of the coal-in-gas is not only beneficial to adjusting the flame length, but also can utilize the oxygen-containing gasifying agent provided by the gasifying agent channel to be quickly mixed with the dry coal powder provided by the dry coal powder channel, thereby ensuring that the temperature distribution of the high-temperature zone of the gasification chamber is more uniform, namely the temperature distribution near the flat-flame type gasification burner 21 is more uniform.

Moreover, by arranging the distributor 100, the dry pulverized coal can be uniformly conveyed into the gasification chamber only by arranging a conveying pipeline for conveying the dry pulverized coal to the flat-flame type gasification burner 21, so that the investment cost (the investment of equipment and a monitoring system of a conveying pipeline) and the operation cost of conveying the dry pulverized coal can be greatly reduced. Therefore, by providing the distributor 100, dry pulverized coal can be supplied to a plurality of dry pulverized coal passages without increasing investment cost and operation cost, so that a plurality of burner units 25 can be provided on the gasification chamber.

Therefore, the flat-flame type gasification burner 21 has the advantages of long service life and the like, and the flat-flame type gasification burner 21 can enhance the gas-solid mixing rate, further improve the gasification reaction efficiency, reduce the short circuit condition of solid particles in the gasification chamber, reduce the volume of the gasification chamber, reduce the manufacturing cost of the gasification chamber and reduce the operation cost of the gasification chamber.

As shown in fig. 9, according to a preferred embodiment of the present invention, the distributor 100 includes a main pipe 110 and a plurality of dry pulverized coal distribution pipes 30. The main tube 110 has a convergent section 113, a constant section 114 and an divergent section 115 connected in series. The contraction section 113 is adjacent to the inlet 111, and the expansion section 115 is adjacent to the outlet 112, that is, among the contraction section 113, the constant section 114 and the expansion section 115, the inlet 111 is closest to the contraction section 113, and the outlet 112 is closest to the expansion section 115. In other words, along the direction from the inlet 111 to the outlet 112, there are a contraction section 113, a constant section 114, and an expansion section 115 in this order. That is, the contraction section 113 is located between the inlet 111 and the constant section 114, and the expansion section 115 is located between the constant section 114 and the outlet 112.

The cross-sectional area of the contraction section 113 decreases in the direction from the inlet 111 to the outlet 112, the cross-sectional area of the constant section 114 does not change in the direction from the inlet 111 to the outlet 112, and the cross-sectional area of the expansion section 115 increases in the direction from the inlet 111 to the outlet 112. Wherein, the direction from the feed port 111 to the discharge port 112 is the flow direction of the dry pulverized coal.

The dry pulverized coal enters the main pipe 110 through the feed inlet 111, namely enters the distributor 100, and sequentially passes through the contraction section 113, the constant section 114 and the expansion section 115 in the main pipe 110. Wherein, the contraction section 113 is used for accelerating the dry pulverized coal particles, the constant section 114 is used for stabilizing the velocity field of the dry pulverized coal particles so as to avoid uneven distribution of the dry pulverized coal particles at the downstream caused by large fluctuation of the flow of the dry pulverized coal particles, and the expansion section 115 is used for evenly distributing the dry pulverized coal particles at each distribution hole 121 according to the velocity inertia.

That is, the dry pulverized coal particles are accelerated in the contraction section 113, enter the expansion section 115 after being stabilized by the constant cross section 114, and finally enter the dry pulverized coal sub-conveying pipes 30 through the distribution holes 121, so that the dry pulverized coal particles are uniformly distributed.

According to the present invention, the distributor 100 is provided with the contraction section 113, the constant section 114 and the expansion section 115 which are connected in sequence, so that the velocity field of the dry pulverized coal particles can be stabilized, and the dry pulverized coal particles can be evenly distributed into the plurality of distribution holes 121 according to the velocity inertia.

According to the present invention, the flat-flame type gasification burner 21 can uniformly distribute dry pulverized coal into a plurality of strands by providing the distributor 100. This further reduces the flame length, and makes the temperature distribution more uniform in the vicinity of the flat-flame gasification burner 21, and thus further reduces the peak temperature value, so that the service life of the flat-flame gasification burner 21 can be further extended.

According to the present invention, the flat flame type gasification burner 21 can uniformly distribute dry pulverized coal particles into a plurality of dry pulverized coal passages communicating with the plurality of distribution holes 121 in a one-to-one correspondence by providing the distributor 100. Therefore, only one main dry coal powder conveying pipeline for conveying dry coal powder to the distributor 100 is needed to be arranged (the main dry coal powder conveying pipeline can be connected with the feeding hole 111 of the main pipe 110 of the distributor 100), so that the dry coal powder can be uniformly conveyed into the gasification chamber, and the investment cost (the investment of equipment and a monitoring system of a conveying pipeline) and the operation cost of conveying the dry coal powder can be greatly reduced. That is, when the flat-flame type gasification burner 21 has a plurality of burner units 25, N-1 conveying pipes for conveying dry pulverized coal to the burner units 25 and a monitoring system for monitoring the conveying pipes can be omitted by providing the distributor 100, where N is the number of the burner units 25.

Specifically, the distributor 100 may be disposed at the upper part of the gasification chamber, and the upper end of the main pipe 110 of the distributor 100 may be connected to the main dry coal powder conveying pipe by a flange, a ferrule, welding, or other connection means. The inner diameter at the interface of the main pipe 110 may be the same as that of the main dry pulverized coal conveying pipe, and a portion of the main dry pulverized coal conveying pipe adjacent to the main pipe 110 may be maintained in a straight pipe state to avoid a sudden change in pipe resistance. The main dry coal powder conveying pipeline can be connected with a material sending tank.

The plurality of distribution holes 121 may be connected to the plurality of dry coal powder pipes through the plurality of dry coal powder branch conveyance pipes 30 in a one-to-one correspondence. That is, the dry coal powder may exit the dispenser 100 through a plurality of distribution holes 121 at the discharge port 112.

The dry coal powder is distributed by the distributor 100 and uniformly distributed into the dry coal powder distribution and transportation pipelines 30, and then enters the dry coal powder channels through the dry coal powder distribution and transportation pipelines 30.

Specifically, each dry coal powder sub-delivery pipe 30 may be connected to the cover plate 120 by a flange, a ferrule, welding, or other connection means. The plurality of dry pulverized coal distribution pipes 30 may be symmetrical with respect to a center line of the distributor 100.

As shown in fig. 9, the upper end of the constant-section 114 may be connected to the lower end of the contraction section 113, and the lower end of the constant-section 114 may be connected to the upper end of the expansion section 115. Preferably, the main tube 110 may be circular in cross-section, the constant section segment 114 may be cylindrical, and each of the convergent segment 113 and divergent segment 115 may be frustoconical. Thereby making the structure of the dispenser 100 more rational.

The ratio of the maximum cross-sectional area to the minimum cross-sectional area of the contraction section 113 may be 1.05-4.5:1, and the ratio of the maximum cross-sectional area to the minimum cross-sectional area of the expansion section 115 may be 1.1-5: 1. Preferably, the ratio of the maximum cross-sectional area to the minimum cross-sectional area of the contraction section 113 may be 1.25 to 2:1, and the ratio of the maximum cross-sectional area to the minimum cross-sectional area of the expansion section 115 may be 1.5 to 2.5: 1.

Preferably, the sum of the cross-sectional areas of the plurality of distribution holes 121 may be equal to or greater than the cross-sectional area of the feed port 111, the sum of the cross-sectional areas of the plurality of distribution holes 121 may be equal to or greater than the cross-sectional area of the main dry coal powder conveying pipe, the sum of the cross-sectional areas of the plurality of sub-dry coal powder conveying pipes 30 may be equal to or greater than the cross-sectional area of the main dry coal powder conveying pipe, and the sum of the cross-sectional areas of the plurality of sub-dry coal powder conveying. The cross-sectional area of the feed port 111 is equal to or greater than the cross-sectional area of the main dry pulverized coal conveying pipe.

More preferably, the sum of the cross-sectional areas of the plurality of distribution holes 121 may be equal to the cross-sectional area of the feed port 111, the sum of the cross-sectional areas of the plurality of distribution holes 121 is equal to the cross-sectional area of the main dry coal powder conveying pipe, the sum of the cross-sectional areas of the plurality of sub-dry coal powder conveying pipes 30 is equal to the cross-sectional area of the main dry coal powder conveying pipe, and the sum of the cross-sectional areas of the plurality of sub-dry coal powder conveying pipes 30 is equal to the cross. The cross-sectional area of the feed port 111 is equal to the cross-sectional area of the main dry pulverized coal conveying pipe.

As shown in fig. 8 and 9, in a specific embodiment of the present invention, the dispenser 100 may further include a purge pipe 130. The purge tube 130 may be sleeved on the main tube 110, and the purge tube 130 may be opposite to at least one of the contraction section 113, the constant-section 114, and the expansion section 115 in a radial direction of the main tube 110. In other words, the purge tube 130 may be sleeved on at least one of the constricted section 113, the constant section 114, and the expanded section 115.

An annular purge cavity 131 may be formed between the purge tube 130 and the main tube 110. The purge pipe 130 may be provided with a purge gas inlet 132 communicating with the purge chamber 131, and a wall surface of at least one of the contraction section 113, the constant-section 114, and the expansion section 115 may be provided with a through hole communicating with the purge chamber 131.

Wherein purge gas can enter the purge chamber 131 through the purge gas inlet 132 and then enter the main pipe 110 through the through hole. By purging the dry pulverized coal particles in the main pipe 110 with the purge gas, not only can accumulation of the dry pulverized coal particles on the inner wall of the main pipe 110 be avoided, but also the dry pulverized coal particles near the wall surface of the main pipe 110 can be accelerated to make the flow of the dry pulverized coal particles in the main pipe 110 close to the plug flow, and particularly to make the dry pulverized coal particles close to the plug flow distribution in the constant-section 114 and the expanded section 115.

That is, by externally covering the main pipe 110 with the purge pipe 130, it is possible to prevent clogging due to accumulation of dry pulverized coal particles on the wall surface of the main pipe 110 or unstable flow of the dry pulverized coal particles, and accelerate the dry pulverized coal particles near the wall surface of the main pipe 110.

Preferably, the purge tube 130 may be radially opposite the constant cross-section 114 from the main tube 110. Specifically, the upper end of the purge tube 130 may be flush with the upper end of the constant-section 114 and the lower end of the purge tube 130 may be flush with the lower end of the constant-section 114, so as to keep the dry coal dust particles in a purged state throughout the constant-section 114. The length of the purge pipe 130 can thereby be reduced while substantially ensuring the purge effect described above.

Further, the upper end of the purge pipe 130 may be higher than the upper end of the constant-section 114, and the lower end of the purge pipe 130 may be lower than the lower end of the constant-section 114, i.e., the purge pipe 130 may be opposed to at least a portion of the contraction section 113 and at least a portion of the expansion section 115 in the radial direction of the main pipe 110. Therefore, the pressure jump caused by the sudden change of the sectional area of the pipeline where the dry pulverized coal particles flow through the main pipe 110 (the pressure jump easily causes the accumulation and blockage of the dry pulverized coal particles) can be avoided.

As shown in FIG. 9, the distributor 100 may further comprise a filter layer 133, and the filter layer 133 may be provided between the purge gas inlet 132 and the through-hole. In other words, the filter layer 133 may be fitted over the main pipe 110, and the filter layer 133 may be located between the purge pipe 130 and the equal-section 114, and the purge gas may be introduced into the main pipe 110 through the purge gas inlet 132, the filter layer 133, and the through hole in this order. Whereby the sweep gas entering the main pipe 110 can be filtered by the filter layer 133. Specifically, the filter layer 133 may be made of sintered metal.

Preferably, the purge gas inlet 132 may be plural, and the through hole may be plural. The plurality of purge gas inlets 132 may be equally spaced in the circumferential direction of the purge pipe 130Provided on the purge pipe 130, a plurality of the through holes may be provided on the main pipe 110 at equal intervals in the circumferential and radial directions of the main pipe 110. This makes it possible to introduce the purge gas into the main pipe 110 more uniformly, and the purge effect can be further improved. The purge gas may be N₂、CO₂The conveying gas for conveying the dry pulverized coal can also be a gas medium such as synthesis gas generated by a gasification chamber, so that the influence on effective gas components in the synthesis gas obtained by gasifying the dry pulverized coal is reduced.

As shown in fig. 10 and 11, a plurality of dispensing holes 121 may be provided in the cap plate 120 at equal intervals in the circumferential direction of the main pipe 110. That is, a plurality of dispensing holes 121 may be provided on the lid plate 120 at equal intervals in the circumferential direction of the lid plate 120. Therefore, the distributor 100 can distribute dry coal powder into the distribution holes 121 more uniformly and further into the dry coal powder distribution conveying pipelines 30, and the dry coal powder distribution conveying pipelines 30 are respectively communicated with the dry coal powder channels of the corresponding burner units 25.

An angle between the center line of each dispensing hole 121 and the center line of the main tube 110 may be 2 degrees or more and 60 degrees or less. Preferably, the angle between the center line of each dispensing hole 121 and the center line of the main tube 110 may be 20 degrees or more and 45 degrees or less. Preferably, the plurality of dispensing holes 121 may be symmetrical with respect to a center line of the dispenser 100 (i.e., a center line of the main pipe 110).

As shown in fig. 11, in one example of the present invention, the dispenser 100 may further include a distribution member 140, the distribution member 140 may be provided on the cap plate 120, and the distribution member 140 may be located inside the main pipe 110. Wherein the cross-sectional area of the distribution member 140 may increase in a direction from the inlet port 111 to the outlet port 112. Specifically, the distribution member 140 may be provided on an upper surface of the cover plate 120, and the cross-sectional area of the distribution member 140 may increase from top to bottom.

Since the cross-sectional area of the distribution member 140 may decrease in a direction from the discharge port 112 to the feed port 111, that is, the cross-sectional area of the distribution member 140 may decrease from bottom to top, the distribution member 140 has a wedge effect on the dry pulverized coal particles flowing therethrough so as to divide the dry pulverized coal particles. The distribution member 140 thus distributes the dry coal fines along the annulus, thereby avoiding distribution differences that may result from uneven distribution of the dry coal fines at the axial center of the main tube 110 and near the wall surfaces (particularly at the axial center of the expanding section 115 and near the wall surfaces). Wherein the annulus space may be the space between distribution member 140 and the wall of main tube 110 (expanding section 115). The dispensing member 140 may be considered a plug having a plugging effect.

Preferably, the distribution member 140 may be conical or pyramid-shaped. The dry coal dust particles can thus be better tapered so that they can be more evenly spatially distributed along the ring system. The dispensing member 140 may be welded to the cover plate 120, and the dispensing member 140 may be coupled to the cover plate 120 by a screw or a flange.

In a specific example of the present invention, the distance between the center line of the distributing member 140 and the center line of the main pipe 110 (the center line of the expanding section 115) in the horizontal direction is equal to or less than the second preset value. The centerline of the distributing member 140 may thereby be positioned adjacent to the centerline of the main tube 110 so that the dry coal fines particles may be divided along the centerline adjacent to the main tube 110 so that the dry coal fines may be more evenly distributed along the annular system space.

Preferably, the centerline of the distribution member 140 coincides with the centerline of the main tube 110. The dry coal fines particles can thereby be divided along the centerline of the main tube 110, resulting in a more uniform distribution of the dry coal fines along the annulus.

As shown in fig. 10 and 11, a partition 150 is provided between two adjacent distribution holes 121, the partition 150 is provided on the lid plate 120, and the partition 150 extends from the lid plate 120 in a direction adjacent to the feed opening 111. Specifically, the partition 150 is provided on the upper surface of the cap plate 120, and the partition 150 extends upward from the cap plate 120. Whereby adjacent two dispensing apertures 121 may be separated by a partition 150.

By providing the partitioning member 150 between the two adjacent distribution holes 121, the partitioning member 150 may be plural, and the plural partitioning members 150 may be provided at equal intervals in the circumferential direction of the main pipe 110, so that not only the dry pulverized coal may be primarily distributed by the partitioning member 150, but also the flow of the dry pulverized coal flowing to each distribution hole 121 may be restricted, so as to reduce flow fluctuation of the dry pulverized coal flowing to the distribution holes 121 due to the mixed flow of the dry pulverized coal in the tangential direction of the main pipe 110 (the expanding section 115).

More preferably, the inner ends of the plurality of partitions 150 are connected to each other, i.e., the plurality of partitions 150 may be radial. Thereby making the structure of the dispenser 100 more rational.

As shown in fig. 10 and 11, in an embodiment of the present invention, the dispenser 100 may further include the above-described dispensing member 140 and the partition 150. Wherein a portion of the first edge of the partition 150 is connected to the cover plate 120, and the remaining portion of the first edge of the partition 150 is connected to the circumferential surface of the distribution member 140. Specifically, a portion of the lower edge of the partition 150 is connected to the cover plate 120, and the remaining portion of the lower edge of the partition 150 is connected to the circumferential surface of the distribution member 140.

The distribution member 140 and the partition member 150 can perform primary distribution of the dry pulverized coal more uniformly, and the partition member 150 can perform flow restriction of the dry pulverized coal flowing to each distribution hole 121 more uniformly, so as to further reduce flow fluctuation of the dry pulverized coal flowing to the distribution holes 121 due to the mixed flow of the primarily distributed dry pulverized coal in the tangential direction of the main pipe 110 (the expanded section 115).

Preferably, an inner end of a first rim of the partition 150, an inner end of a second rim of the partition 150, which is opposite to the first rim, and a top end of the dispensing member 140 coincide. Specifically, the first edge is a lower edge of the separator 150, and the second edge is an upper edge of the separator 150. Thereby making the structure of the dispenser 100 more rational.

As shown in fig. 11, the second edge of the partition 150 is configured to be streamlined as being recessed toward the cover plate 120. It is possible to prevent the separator 150 from having an edge whose structure is abruptly changed, so that generation of eddy current can be prevented. Wherein, when the second edge of the partition member 150 is viewed from the top down, the second edge of the partition member 150 is recessed toward the cap plate 120, i.e., the second edge of the partition member 150 is recessed downward. When the second edge of the partition member 150 is viewed from below to above, the second edge of the partition member 150 protrudes toward the cover plate 120, that is, the second edge of the partition member 150 protrudes downward.

Preferably, as shown in fig. 11, the cover plate 120 may have a plurality of distribution portions 122 recessed in a direction away from the feed opening 111, the plurality of distribution portions 122 being provided at intervals in the circumferential direction of the main pipe 110, each distribution portion 122 being provided with one distribution hole 121. This makes it possible to make the distribution holes 121 higher around than the distribution holes 121, thereby preventing the dry pulverized coal from accumulating around the distribution holes 121 and not flowing.

Wherein the distribution portion 122 is recessed downward when the cover plate 120 is viewed from above. When the cover plate 120 is viewed from below to above, the distribution portion 122 protrudes downward.

Preferably, the dispensing hole 121 may be located at the bottom of the dispensing part 122. Thereby, it is possible to further prevent dry coal powder from accumulating and not flowing around the distribution holes 121. The portion of the cover plate 120 between the adjacent two distribution parts 122 may constitute a partition 150. Thereby making the structure of the dispenser 100 more rational.

As shown in fig. 3, it is preferable that the flat-flame type gasification burner 21 does not have a distributor. A plurality of strands of dry pulverized coal (shown in fig. 7) from the material conveying unit 1 are conveyed to the corresponding burner units 25, respectively. That is, one minute more of the dry pulverized coal is completed in the material transporting unit 1.

According to the present invention, the system preferably further comprises a material conveying unit 1, said material conveying unit 1 being adapted to convey said dry coal powder to a gasification unit 2.

Preferably, the material conveying unit 1 comprises a silo 11, a pulverized coal lock hopper 12 and a material sending tank 20.

According to the invention, the discharge mode of the material conveying unit 1 according to the invention can be designed according to the structure of the flat-flame gasification burner 21.

In order to better achieve stable discharge of the dry pulverized coal, the invention provides a particularly preferred embodiment, so that the material sending tank 20 can better achieve stable discharge of the dry pulverized coal.

Referring now to fig. 12 and 13, the dispensing can 20 of the present invention is described in detail, and the dispensing can 20 may include a can body 210, a fluidization plate 220, and a discharge pipe 230.

The can 210 has a receiving cavity 211 therein. The fluidization plate 220 is provided in the receiving chamber 211 to divide the receiving chamber 211 into a dry pulverized coal chamber 212 and a fluidization chamber 213, the fluidization chamber 213 being located below the dry pulverized coal chamber 212, the fluidization chamber 213 being communicated with the dry pulverized coal chamber 212. An air inlet 214 is provided on a side wall surface of the fluidizing chamber 213.

The sidewall surface of the dry pulverized coal chamber 212 is provided with a plurality of through holes, and the plurality of through holes are arranged at intervals along the circumferential direction of the dry pulverized coal chamber 212. Preferably, a plurality of the through holes are provided on a side wall surface of the dry pulverized coal chamber 212 at equal intervals in a circumferential direction of the dry pulverized coal chamber 212.

The plurality of discharging pipes 230 are provided, and the first portions of the plurality of discharging pipes 230 pass through the plurality of through holes in a one-to-one correspondence so as to extend into the dry coal powder chamber 212. That is, the number of tappets 230 may be equal to the number of via holes through which the first portion of a tapper 230 passes.

Because the dry pulverized coal is stressed equally in the horizontal direction, the dry pulverized coal can easily enter the plurality of discharge pipes 230 in a suspension flow mode, so that the dry pulverized coal can be stably output, and the flow inequality of the dry pulverized coal of each discharge pipe 230 is avoided. This allows the dry coal fines to enter the plurality of outlet pipes 230 uniformly, so that a uniform distribution of the dry coal fines is achieved.

The distance between the feed inlet of the discharge pipe 230 and the upper surface 221 of the fluidization plate 220 in the vertical direction is less than or equal to the second preset value and greater than or equal to the third preset value. By making the distance between the inlet opening of the discharge pipe 230 and the upper surface 221 of the fluidization plate 220 in the vertical direction greater than or equal to the third preset value, a sufficient space between the discharge pipe 230 and the fluidization plate 220 can be provided to accommodate the dry pulverized coal.

The distance between the feed inlet of the discharge pipe 230 and the upper surface 221 of the fluidization plate 220 in the vertical direction is smaller than or equal to the second preset value, so that the fully fluidized dry coal powder can rapidly enter the discharge pipe 230, and further can rapidly enter the substantially horizontally arranged part of the discharge pipe 230, namely, the dry coal powder can enter the substantially horizontally arranged part of the discharge pipe 230 at a flow velocity higher than the settling velocity, so that the stability of conveying the dry coal powder can be improved, and the discharge stability of the material sending tank 20 can be further improved.

Wherein, the distance between the feed inlet of the discharge pipe 230 and the upper surface 221 of the fluidization plate 220 in the vertical direction is: the inlet opening of the outlet pipe 230 is located opposite a first part of the upper surface 221 of the fluidization plate 220 in the vertical direction, and the distance between the inlet opening of the outlet pipe 230 and this first part of the upper surface 221 of the fluidization plate 220 in the vertical direction is the distance between the inlet opening of the outlet pipe 230 and the upper surface 221 of the fluidization plate 220 in the vertical direction.

As shown in fig. 13, the fluidizing plate 220 has a peripheral edge connected to a side wall surface of the accommodating chamber 211, and the fluidizing plate 220 is provided with a plurality of through holes (not shown) through which the dry coal powder chamber 212 communicates with the fluidizing chamber 213. Thus, by uniformly providing a plurality of the through holes on the fluidization plate 220, the fluidization air is uniformly introduced into the dry pulverized coal chamber 212, so that the dry pulverized coal in the dry pulverized coal chamber 212 is more sufficiently fluidized and more uniformly distributed.

Preferably, the fluidization plate 220 may be a sintered metal plate. The pore size of the sintered metal sheet may be 1/3-2/3 of the average particle size of the dry coal fines, thereby ensuring that the dry coal fines enter the fluidization chamber and do not clog the sintered metal sheet.

According to a specific embodiment, as shown in fig. 13, the upper surface 221 of the fluidization plate 220 has a beveled portion with an outer edge below an inner edge of the beveled portion. That is, the slope portion is inclined downward in the inward-outward direction. Wherein, the direction near the middle of the accommodating cavity 211 is inward, and the direction far away from the middle of the accommodating cavity 211 is outward.

By providing the upper surface 221 of the fluidization plate 220 with the slope portion, the dry pulverized coal can flow downward and outward along the slope portion under its own weight, i.e., toward the side wall surface of the dry pulverized coal chamber 212. Therefore, the fluidity of the dry coal powder can be improved, the dry coal powder can be more sufficiently fluidized, and the dry coal powder can more easily enter the discharge pipe 230.

Preferably, the beveled portion is opposite to the first portion of the tapping pipe 230 in the inner and outer directions. This makes it easier for dry coal to enter the discharge pipe 230. The inside-outside direction is shown by an arrow D in fig. 13.

Preferably, the included angle between the inclined plane part and the horizontal plane is more than 0 degree and less than or equal to 20 degrees. More preferably, the included angle between the inclined surface part and the horizontal plane is greater than 0 degree and less than or equal to 15 degrees. Therefore, the flowability of the dry coal powder can be further improved, the dry coal powder is prevented from being deposited on the fluidization plate 220, the dry coal powder is more sufficiently fluidized, and the dry coal powder can more easily enter the discharge pipe 230.

According to a specific embodiment, the upper surface 221 of the fluidization plate 220 is conical. As shown in fig. 13, the fluidization plate 220 includes a conical portion 222 and a cylindrical portion 223, and a lower surface of the conical portion 222 is connected to an upper surface of the cylindrical portion 223, i.e., the conical portion 222 is provided on the upper surface of the cylindrical portion 223. The circumferential surface of the cylindrical portion 223 is continuous with the side wall surface of the accommodation chamber 211, and the circumferential surface (side surface) of the conical portion 222 constitutes the inclined surface portion. The up-down direction is shown by arrow C in fig. 13.

Preferably, the edge (lower edge) of the conical portion 222 is flush with the edge of the cylindrical portion 223, whereby the dry pulverized coal can be made to flow to the side wall surface of the dry pulverized coal chamber 212, so that the dry pulverized coal can be more sufficiently fluidized, so that the dry pulverized coal can be more easily introduced into the discharge pipe 230. Preferably, the included angle between the generatrix of the conical portion 222 and the horizontal plane is greater than 0 degree and equal to or less than 20 degrees. More preferably, an angle between a generatrix of the conical portion 222 and a horizontal plane is greater than 0 degrees and equal to or less than 15 degrees.

According to a specific embodiment, the fluidization plate 220 includes a circular table portion and a cylindrical portion, and a lower surface of the circular table portion is connected to an upper surface of the cylindrical portion, i.e., the circular table portion is provided on the upper surface of the cylindrical portion. Wherein the peripheral surface of the cylindrical portion is connected to the side wall surface of the accommodation chamber 211, and the peripheral surface (side surface) of the circular truncated cone portion constitutes the inclined surface portion.

Preferably, the lower edge of the circular truncated cone portion is flush with the edge of the cylindrical portion, so that the dry pulverized coal can flow to the side wall surface of the dry pulverized coal chamber 212, and the dry pulverized coal can be more sufficiently fluidized, so that the dry pulverized coal can be more easily introduced into the discharge pipe 230. Preferably, the included angle between the generatrix of the circular truncated cone and the horizontal plane is greater than 0 degree and less than or equal to 20 degrees. More preferably, an included angle between a generatrix of the circular truncated cone portion and a horizontal plane is greater than 0 degree and equal to or less than 15 degrees.

As shown in fig. 13, the hair spray can 20 further includes a distribution boss 240, and the distribution boss 240 is provided at the middle of the upper surface 221 of the fluidization plate 220. Through the arrangement of the distributing boss 240, the dry pulverized coal can be primarily distributed by the distributing boss 240, so that the dry pulverized coal can be prevented from being accumulated in the middle of the fluidization plate 220, and the dry pulverized coal is more sufficiently fluidized.

Preferably, the upper surface of the material separating boss 240 is a portion of a spherical surface. Therefore, the distributing boss 240 can better perform primary distributing on the dry pulverized coal.

As shown in fig. 13, in some embodiments of the invention, this first portion of the tapping pipe 230 comprises a vertical section 233, the lower mouth of the vertical section 233 constituting the feed opening of the tapping pipe 230. Wherein, the length-diameter ratio of the vertical section 233 is less than or equal to a first preset value. In particular, the vertical section 233 may be arranged vertically, i.e. the vertical section 233 may extend in a vertical direction, when the hair canister 20 is in use.

By making the aspect ratio of the vertical section 233 equal to or less than the first preset value, the length of the vertical section 233 can be made smaller. From this, the dry pulverized coal sufficiently fluidized can pass through the vertical section 233 quickly, so that the dry pulverized coal can enter the substantially horizontally disposed part of the discharge pipe 230 quickly, that is, the dry pulverized coal can enter the substantially horizontally disposed part of the discharge pipe 230 at a flow rate higher than the settling velocity, so that the stability of conveying the dry pulverized coal can be improved, that is, the discharge stability of the material dispensing tank 20 can be further improved.

Preferably, the first preset value is less than or equal to 2. More preferably, the first preset value is 1.7 or less. Most preferably, the first preset value is less than or equal to 1.3. This can further improve the discharge stability of the material dispensing can 20.

Preferably, the length of the vertical section 233 may be 50 cm or less. More preferably, the length of the vertical section 233 may be 40 cm or less. Further preferably, the length of the vertical section 233 may be 30 cm or less. Most preferably, the length of the vertical section 233 may be 20 cm or less.

Preferably, the distance between the lower end surface (lower surface) of the vertical section 233 and the upper surface 221 of the fluidization plate 220 in the up-down direction is less than or equal to the second preset value and greater than or equal to the third preset value. Therefore, not only can enough space be reserved between the vertical section 233 (the discharge pipe 230) and the fluidization plate 220 to accommodate the dry pulverized coal, but also the stability of conveying the dry pulverized coal can be improved, that is, the discharge stability of the material sending tank 20 can be further improved.

Wherein, the distance between the lower end surface of the vertical section 233 and the upper surface 221 of the fluidization plate 220 in the up-down direction is: the lower end face of the vertical section 233 is opposed to the first portion of the upper surface 221 of the fluidization plate 220 in the up-down direction, and the distance between the lower end face of the vertical section 233 and the first portion of the upper surface 221 of the fluidization plate 220 in the up-down direction is the distance between the lower end face of the vertical section 233 and the upper surface 221 of the fluidization plate 220 in the up-down direction.

More preferably, the second preset value is 20 cm; further preferably, the second preset value is 10 cm. More preferably, the third preset value is 1 cm; further preferably, the third preset value is 2 cm.

As shown in FIG. 13, according to a specific embodiment, the tapping pipe 230 comprises a horizontal section 231, a transition section 232 and a vertical section 233. A portion of the horizontal section 231 passes through the through hole and extends into the dry coal powder chamber 212, and an end of a portion of the horizontal section 231 is connected to an upper end of the vertical section 233 through the transition section 232.

That is, the portion of the horizontal segment 231, the transition segment 232, and the vertical segment 233 are located within the dry coal powder chamber 212. When the hair pot 20 is in use, the horizontal section 231 may be horizontally disposed, i.e., the horizontal section 231 may extend in a horizontal direction.

Therefore, the fully fluidized dry pulverized coal can rapidly pass through the vertical section 233 and the transition section 232, so that the dry pulverized coal can rapidly enter the horizontal section 231, that is, the dry pulverized coal can enter the horizontal section 231 at a flow velocity higher than the settling velocity, so that the stability of conveying the dry pulverized coal can be improved, and the discharge stability of the material sending tank 20 can be further improved.

Preferably, the transition 232 may be a 90 ° bend, thereby making the construction of the hair styling pot 20 more rational.

According to the invention, during operation of the dispensing can 20: fluidizing air enters the fluidizing chamber 213 through the air inlet 214 and into the dry coal powder chamber 212. The dry coal powder enters the dry coal powder chamber 212 and flows downward in the dry coal powder chamber 212 under its own weight. The fully fluidized dry coal fines enter the discharge pipe 230.

Since the dry coal powder chamber 212 is located above the fluidizing chamber 213, the fluidizing air blows the dry coal powder upward, whereby compaction of the dry coal powder in the dry coal powder chamber 212 can be avoided, and discharge instability and discharge interruption can be avoided.

Since a first portion of the discharge pipe 230 passes through a sidewall surface of the dry coal cavity 212 so as to protrude into the dry coal cavity 212, the dry coal powder is discharged (away from the dry coal cavity 212) in a substantially horizontal (near-horizontal) direction. Therefore, the continuous reduction of the flow velocity of the dry pulverized coal under the action of the gravity of the dry pulverized coal can be avoided, the blockage of the dry pulverized coal can be avoided, and the problem of intermittent discharging can be further solved.

In addition, in the horizontal direction, the dry coal powder is equally stressed, so that the dry coal powder can easily enter the discharge pipe 230 in a suspension flow mode, and the dry coal powder can be stably output.

According to the material sending tank 20 for the gasification system, the material outlet pipe 230 penetrating through the side wall surface of the dry coal powder cavity 212 is arranged, and the dry coal powder cavity 212 is positioned above the fluidization cavity 213, so that the dry coal powder in the dry coal powder cavity 212 can be prevented from being compacted, the flow rate of the dry coal powder can be prevented from being reduced, and the stable discharging of the dry coal powder can be realized.

As shown in fig. 6, if the feeding manner of the flat-flame type gasification burner 21 is to uniformly feed all the burner units 25, the feed tank 20 of the material feeding unit 1 is provided with only one outlet, and the outlet is communicated with the dry coal powder inlet of the flat-flame type gasification burner 21 to feed the dry coal powder to the flat-flame type gasification burner 21. On the other hand, as shown in fig. 7, if the flat flame type gasification burners 21 are fed independently for each burner unit 25, the feed tank 20 of the material feed unit 1 has a plurality of discharge ports corresponding to the number of burner units 25, and a plurality of strands of dry pulverized coal flows through the respective discharge ports into the respective burner units 25.

Preferably, according to a specific embodiment of the present invention, the pressure in the gasification chamber 2 is 4.0MPa, so that the dry pulverized coal needs to be transported under pressure in the material transportation unit 1, and therefore, a pulverized coal lock 12 is preferably disposed between the silo 11 and the material sending tank 20, although other pressure buffer vessels can be used to transport the material under pressure.

According to the invention, the dry coal fines have an average residence time t in the gasification chamber 22 provided with a single nozzle, with the same gasification chamber volume_m4.41s, and 72.54% of the particles leave the gasification chamber before the average residence time, which shows that the gasification chamber provided with the single nozzle has the defects of serious short circuit and low gas-solid mixing efficiency; the dry coal dust has an average residence time t in the gasification chamber 22 provided with the flat-flame type gasification burner 21_m16.09s and the smallest dimensionless variance σ θ 2 is 0.2, while only 58.57% of the particles leave the gasification chamber before the mean residence time. Thus, the gasification chamber provided with the flat-flame type gasification burner 21 has a more uniform particle residence time distribution, higher mixing efficiency, and a larger residence time for the same gasification chamber volume. Comparing the temperature fields of the two in the gasification chamber 22, the flat-flame type gasification burner 21 has a shorter flame length, the temperature is more uniformly distributed near the flat-flame type gasification burner 21, and the peak value of the temperature is reduced, which contributes to the improvement of the life of the flat-flame type gasification burner 21.

Since the average residence time of the gasification chamber provided with the flat-flame type gasification burner 21 is four times as long as that of the gasification chamber provided with a single nozzle, the volume of the gasification chamber provided with the flat-flame type gasification burner 21 can be 1/4 of the volume of the gasification chamber provided with a single nozzle with the same average residence time. Thus, even if the volume of the gasification chamber provided with the flat-flame type gasification burner 21 is reduced, the reaction requirement can be satisfied, and the volume of the gasification chamber can be reduced, thereby reducing the manufacturing cost of the gasification chamber.

Preferably, the aspect ratio of the vaporizing chamber 22 is (0.5-10): 1, more preferably (1-3): 1, more preferably (1-2): 1.

s1, respectively introducing a gasifying agent and dry coal powder into a gasification unit 2 through a flat flame type gasification burner 21, enabling the gasifying agent and the dry coal powder to collide in a gasification chamber 22 of the gasification unit 2 and ignite to form flat flame, and enabling the gasifying agent and the dry coal powder to perform gasification reaction to generate crude synthesis gas and molten slag;

s2, cooling the crude synthesis gas and the slag in the first heat exchange unit 23 to obtain a first crude synthesis gas and cooled slag, and generating steam as a byproduct;

According to the invention, the number of clusters of the flames formed after collision and ignition is preferably equal to the number of the burner units 25, and the flames of each cluster are parallel to each other, the length of each flame cluster is 5-30 times, preferably 7-15 times, the distance between the collision point and the end face of the burner unit 25, and the diameter of each flame cluster is about 2-3 times of OC.

According to the invention, preferably, the method further comprises the steps of dedusting the first raw synthesis gas by a dedusting unit 8, and then washing the first raw synthesis gas in a washing unit 6; further preferably, the dedusting process is carried out at 500-850 ℃.

In the present invention, the gasification agent is not particularly limited, and may be one that is well known in the art and can be used for dry pulverized coal gasification, and for example, oxygen and/or air may be used.

According to the present invention, preferably, the reaction conditions of the gasification comprise: the reaction pressure is 0-4.0MPa, and the reaction temperature is 1200-1500 ℃.

According to the present invention, preferably, the temperature of the first raw synthesis gas is 600-;

according to the invention, the pressure of the steam byproduct generated in the primary heat exchange in the step S2 is preferably 3.3-5 MPa.

The method according to the second aspect of the invention can be carried out in the system according to the first aspect of the invention.

The method for performing dry pulverized coal gasification in the system according to the first aspect of the present invention will be described in detail with reference to fig. 1 to 7.

Dry coal powder is conveyed to a material conveying unit 1, the dry coal powder is generally carried by inert gas such as nitrogen and the like and is output to a gasification unit 2 in a dense phase conveying mode, and in the conveying unit 1, the dry coal powder can sequentially pass through a storage bin 11, a fine coal lock hopper 13 and a material sending tank 20 to form a dry coal powder material flow with specific pressure, speed and gas-solid ratio. The one or more dry coal powder streams leaving the material transfer unit 1 are then passed through a flat flame type gasification burner 21 together with one or more gasification agent streams and introduced into a gasification chamber 22 of the gasification unit 2 where gasification takes place.

By virtue of the unique structural design of the flat flame type gasification burner 21, the dry pulverized coal flow and the corresponding gasification agent flow can be violently collided in the gasification chamber 22, and the collision can cause the dry pulverized coal and the gasification agent to be immediately ignited and form the flat flame which is called in the invention. The raw synthesis gas and the slag generated by the gasification reaction flow downwards by means of inertia, and exchange heat with water in the first heat exchange unit 23 to reduce the temperature, so as to obtain the first raw synthesis gas with the temperature of 600-750 ℃ and the cooled slag, and the water in the first heat exchange unit 23 is heated and output in the form of steam. The cooled slag continuously flows downwards to enter a slag collecting chamber 24, further cooling is realized through spraying of chilling water to form solid slag, then the solid slag and the chilling water are discharged out of the gasification unit 2 together and enter a slag water treatment unit 5, and solid-liquid separation treatment is carried out on the solid slag and slag water in the slag water treatment unit 5.

The first crude synthesis gas is directly led out of the gasification unit 2, enters the dust removal unit 8 for dust removal treatment, and enters the washing unit 6 for washing after dust removal, so as to obtain clean synthesis gas with the temperature of 100-200 ℃. Specifically, in the scrubbing unit 6, solid particles entrained by the first raw synthesis gas are wetted by the scrubbing with water, and further separated from the synthesis gas to form a precipitate at the bottom of the tower, and clean synthesis gas moves upwards and is led out from the scrubbing unit 6.

The grey water discharged from the scrubbing unit 6 is divided into two streams, one being pumped into the gasification unit 2 for use as quench water for quenching the slag and one being fed to a waste water treatment unit 7. The waste water treatment unit 7 also receives the slag water from the slag water treatment unit 5, the slag water and the grey water are pumped into the washing unit 6 as washing water after being purified in the waste water treatment unit 7, and the temperature of the clean synthesis gas is 100-200 ℃.

The steam unit 4 is used for uniformly treating and distributing inlet water and outlet water of units/devices with heat exchange functions in the system, specifically, inlet water of the first heat exchange unit 23 comes from the steam unit 4, water is heated in the first heat exchange unit 23 and is converted into steam, and the steam is also sent into the steam unit 4. If the lining of the furnace wall of the gasification unit 22 is a water-cooled wall, the inlet water of the water-cooled wall comes from the steam unit 4, and the outlet water of the water-cooled wall is also communicated with the steam unit 4. The steam unit 4 may also be provided with a cold water inlet to introduce feed water from outside the system to the first heat exchange unit 23 and/or the water wall, and the steam may or may not exchange heat with water in the steam unit 4, depending mainly on the demand for steam by the processes within or downstream of the system.

According to the entrained-flow bed gasification system and method for dry pulverized coal, the characteristics of high gasification reaction speed, short reaction retention time and high process heat are combined with the flat flame type gasification technology, the size and the structural complexity of a gasification reactor are not increased basically while the process heat of the gasification reaction is reasonably utilized through the first heat exchange unit and the steam unit, and slag water, grey water and chilling water of the system can be directly recycled in the system.

The present invention will be described in detail below by way of examples.

In the following examples, the thermal efficiency = (gas calorific value + first heat exchange unit heat draw)/dry coal fines calorific value; the gas calorific value (MJ) is obtained by calculating the composition calorific value of the synthesis gas.

The dry coal dust used in the following examples and comparative examples had an average particle size of 75 μm.

Example 1

In this example, referring to fig. 1, table 1 shows coal quality analysis data of the dry pulverized coal used in this example.

In this example, the operating conditions of the gasification unit were: the pressure is 4.0MPa, and the reaction temperature is 1400 ℃; the height-diameter ratio of the gasification chamber 22 is 2: 1; the treatment capacity of the gasification unit is 2000 tons/day; the flat flame type gasification burner comprises three burner units which are uniformly arranged at intervals along the circumferential direction, and each burner unit is provided with a dry pulverized coal channel arranged in the center and 3 gasification agent channels arranged around the dry pulverized coal channel; the distance (CP) between the impact point and the end face of the flat flame type gasification burner 21 is 25.68mm, and the distance (OC) between the center of the burner gasification agent and the center of the dry pulverized coal outlet is 12.5 mm; the speed of the dry coal powder leaving the burner unit is 9m/s, and the speed of the gasification agent leaving the burner unit is 80 m/s; the inner wall of the gasification chamber 22 is provided with a membrane type water-cooled wall, a first heat exchange unit is arranged below the gasification chamber 22, and a slag collecting chamber is arranged below the first heat exchange unit.

Through a flat flame type gasification burner 21, pure oxygen is used as a gasification agent to be collided and mixed with dry pulverized coal from a material conveying unit 1 and ignited, then the mixture enters a gasification chamber 22 with a water-cooled wall in a tube structure to carry out gasification reaction, a product obtained by gasification is subjected to primary radiation heat exchange through a first heat exchange unit 23 to obtain first crude synthesis gas and molten slag, and the molten slag is conveyed to a slag collecting chamber 24;

the steam pressure of the first heat exchange unit 23 by-product of the primary radiation heat exchange is 4.0 MPa;

the first crude synthesis gas is dedusted by a dedusting unit 8 and then is conveyed to a washing unit 6 for washing to obtain clean synthesis gas and grey water;

wherein the dust removal process is to use a high-temperature cyclone separator to remove dust at 600 ℃; the temperature of the first crude synthesis gas is 700 ℃, and the temperature of the clean synthesis gas is 150 ℃;

part of the grey water generated by the washing unit 6 is conveyed to the slag collecting chamber 24, the slag is chilled to generate solid slag and slag water, the generated solid slag and slag water are conveyed to the slag water processing unit 5, and the solid slag is recycled by the slag water processing unit 5;

conveying the other part of grey water and slag water to a wastewater treatment unit 7 for purification treatment to obtain washing water, and returning the washing water to a washing unit 6 for washing;

and concentrating the steam by-produced by the water-cooled wall and the primary radiation heat exchange into a steam unit for the system to use or a downstream process. After continued steady operation, the system was analyzed and the results are shown in Table 2.

TABLE 1

Example 2

The system and process of this example are the same as example 1, but wherein the aspect ratio of the gasification chamber is 0.5: 1.

table 1 shows the coal quality analysis data of the dry pulverized coal used in this example. After continued steady operation, the system was analyzed and the results are shown in Table 2.

Example 3

The system and process of this example are the same as example 1, but with a burner unit number of 10.

Example 4

The system and method of this example are the same as example 3, but the system of this example is not provided with a dust removal unit.

Comparative example 1

The system and process of this comparative example are the same as example 1 except that the gasification unit is provided with an overhead burner unit comprising a centrally located dry coal dust channel and a gasification agent channel coaxial with the dry coal dust channel.

Table 1 shows the coal quality analysis data of the dry pulverized coal used in this comparative example. After continued steady operation, the system was analyzed and the results are shown in Table 2.

Comparative example 2

The system and method of this comparative example are the same as example 1, except that three burner units are provided on the top of the gasification unit, each burner unit comprises a dry pulverized coal passage provided in the center and a gasification agent passage provided coaxially with the dry pulverized coal passage, and the dry pulverized coal and the gasification agent sprayed from the three burner units collide with each other on the axis of the gasification unit.

Comparative example 3

The system and method of this comparative example are the same as example 4 except that 10 burner units are provided parallel to each other at the top of the gasification unit, each burner unit comprising a dry pulverized coal passage provided at the center and a gasification agent passage provided coaxially with the dry pulverized coal passage.

Table 1 shows the coal quality analysis data of the dry pulverized coal used in this comparative example. After the continuous stable operation for a period of time, the pipeline is seriously blocked and the operation is stopped. The system was analyzed and the results are shown in table 2.

TABLE 2

It can be seen from the results in table 2 that when the flat flame entrained flow coal gasification system and the gasification method thereof are used for gasification of dry pulverized coal, the thermal efficiency of the system can reach 84.7%, and the specific oxygen consumption and the specific coal consumption are also obviously reduced.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. An entrained flow gasification system for dry coal fines, the system comprising:

the gasification unit (2) comprises a flat flame type gasification burner (21), a gasification chamber (22) and a first heat exchange unit (23) which are arranged from top to bottom in sequence; the flat flame type gasification burner (21) introduces a gasification agent and dry coal powder into the gasification chamber (22), and the dry coal powder and the gasification agent are subjected to gasification reaction in the gasification chamber (22) to generate crude synthesis gas and molten slag; the first heat exchange unit (23) is used for carrying out heat exchange and cooling on the crude synthesis gas and the slag to obtain a first crude synthesis gas, cooled slag and byproduct steam;

the steam unit (4) is communicated with the water inlet and the water outlet of the first heat exchange unit (23), and can perform centralized treatment and distribution on the water inlet of the first heat exchange unit (23) and the byproduct steam;

the flat flame type gasification burner (21) comprises a plurality of burner units (25) arranged at the top of the gasification unit (2), the flat flame type gasification burner (21) enables a gasification agent and dry coal powder to collide in the gasification chamber (22) and be ignited to form flat flames, and the number of the burner units (25) is more than or equal to 3.

2. A system according to claim 1, wherein the burner unit (25) comprises at least one dry coal powder channel and at least one gasifying agent channel, the impact point of the dry coal powder flow and the gasifying agent flow being at a distance CP from the end face of the burner unit (25) which is 1.0-10 times, preferably 3-6 times, the distance OC from the gasifying agent flow to the dry coal powder flow at the end face of the burner unit (25).

3. The system of claim 2, wherein the gasifying agent stream and the coal dust stream are impinged at an angle α of greater than 0 degrees to less than 90 degrees, preferably 15 degrees to 45 degrees, and most preferably 30 degrees.

4. A system according to claim 3, wherein the burner unit (25) comprises:

a dry coal powder channel and a plurality of gasifying agent channels arranged around the dry coal powder channel; or

A gasifying agent channel and a plurality of dry coal powder channels arranged around the gasifying agent channel.

5. A system according to claim 3, wherein the burner unit (25) comprises:

a dry pulverized coal channel arranged in the center of the burner unit (25) and an annular gasifying agent channel arranged around the dry pulverized coal channel; or

A gasifying agent channel arranged at the center of the burner unit (25) and an annular dry coal powder channel arranged around the gasifying agent channel.

6. The system according to claim 1, wherein the gasification chamber (22) is lined with a water wall, the water outlet and the water inlet of which are both in communication with the steam unit (4).

7. The system of any one of claim 1, wherein the gasification chamber (22) has an aspect ratio of (0.5-10): 1, preferably (1-3): 1, more preferably (1-2): 1.

8. the system of any one of claim 1, further comprising: a slag collecting chamber (24), a washing unit (6), a wastewater treatment unit (7) and a dust removal unit (8);

the washing unit (6) is communicated with a first heat exchange unit (23) and is used for washing the first crude synthesis gas to obtain clean synthesis gas and grey water;

the slag collecting chamber (24) is communicated with the slag water processing unit (5) and the washing unit (6) and is used for collecting the cooled slag, the ash water is used for chilling the slag, the generated solid slag and slag water are conveyed to the slag water processing unit (5), and the solid slag is recycled by the slag water processing unit (5);

the waste water treatment unit (7) is communicated with the washing unit (6) and the slag water treatment unit (5) and is used for purifying grey water and slag water to obtain washing water, and the washing water is returned to the washing unit (6) for washing;

the dust removal unit (8) is communicated with the first heat exchange unit (23) and the washing unit (6) and is used for enabling the first crude synthesis gas to enter the washing unit (6) for washing after being subjected to dust removal by the dust removal unit (8).

9. The system according to any one of claims 1-8, wherein the flat flame type gasification burner (21) further comprises a distributor (100), the distributor (100) comprising:

a main pipe (110), wherein the main pipe (110) is provided with a feeding hole (111) and a discharging hole (112); and

the cover plate is arranged on the main pipe (110), the cover plate covers the discharge hole (112), a plurality of distribution holes (121) are formed in the cover plate, and the distribution holes (121) are communicated with the dry pulverized coal channels of the burner units (25) in a one-to-one correspondence mode.

10. The system of claim 9, wherein the main pipe (110) has a converging section (113), a constant cross-sectional section (114) and an expanding section (115) connected in series, wherein the converging section is adjacent to the inlet (111) and the expanding section is adjacent to the outlet (112), the cross-sectional area of the converging section decreases in a direction from the inlet (111) to the outlet (112), the cross-sectional area of the constant cross-sectional section is constant in a direction from the inlet (111) to the outlet (112), and the cross-sectional area of the expanding section increases in a direction from the inlet (111) to the outlet (112).

11. The system according to claim 10, wherein the main tube (110) is circular in cross-section, the constant section (114) is cylindrical and each of the convergent section (113) and the divergent section (115) is frustoconical, preferably the ratio of the maximum cross-sectional area to the minimum cross-sectional area of the convergent section (113) is 1.05-4.5:1, the ratio of the maximum cross-sectional area to the minimum cross-sectional area of the divergent section (115) is 1.1-5:1, more preferably the ratio of the maximum cross-sectional area to the minimum cross-sectional area of the convergent section (113) is 1.25-2:1 and the ratio of the maximum cross-sectional area to the minimum cross-sectional area of the divergent section (115) is 1.5-2.5: 1.

12. The system according to claim 10, wherein the distributor (100) further comprises a purge tube (130), the purge tube (130) is sleeved on the main tube (110), the purge tube (130) is opposite to at least one of the contraction section (113), the constant-section (114) and the expansion section (115) in the radial direction of the main tube (110), wherein an annular purge cavity (131) is formed between the purge tube (130) and the main tube (110), a purge gas inlet (132) communicated with the purge cavity (131) is arranged on the purge tube (130), a through hole communicated with the purge cavity (131) is arranged on the wall surface of the at least one of the contraction section (113), the constant-section (114) and the expansion section (115), preferably, the distributor (100) further comprises a filter layer (133), the filter layer (133) is provided between the purge gas inlet (132) and the through-hole.

13. System according to claim 9, wherein the distributor (100) further comprises a distributor piece (140), the distributor piece (140) being provided on the cover plate (120), the distributor piece (140) being located within the main tube (110), wherein the cross-sectional area of the distributor piece (140) increases in the direction from the feed opening (111) to the discharge opening (112) of the main tube (110), preferably the distributor piece (140) is conical or pyramidal, preferably the distance in the horizontal direction between the centre line of the distributor piece (140) and the centre line of the main tube (110) is smaller than or equal to a second predetermined value, more preferably the centre line of the distributor piece (140) coincides with the centre line of the main tube (110).

14. The system according to any of claims 1-8, wherein the system further comprises a material conveying unit (1), the material conveying unit (1) being adapted to convey the dry coal fines to a gasification unit (2);

preferably, the material conveying unit (1) comprises a storage bin (11), a pulverized coal locking hopper (12) and a material sending tank (20), wherein the material sending tank (20) is provided with a plurality of discharge holes communicated with the burner units (25) in a one-to-one correspondence manner.

15. The system of claim 14, wherein the dispensing canister (20) comprises:

the tank body (210), wherein the tank body (210) is internally provided with a containing cavity (211);

the fluidization plate (220) is arranged in the containing cavity (211) so as to divide the containing cavity (211) into a dry pulverized coal cavity (212) and a fluidization cavity (213), the fluidization cavity (213) is positioned below the dry pulverized coal cavity (212), the fluidization cavity (213) is communicated with the dry pulverized coal cavity (212), a plurality of through holes are formed in the side wall surface of the dry pulverized coal cavity (212), and an air inlet (214) is formed in the wall surface of the fluidization cavity (213); and

a plurality of discharge pipes (230), wherein first parts of the plurality of discharge pipes (230) correspondingly penetrate through the plurality of through holes one by one and extend into the dry pulverized coal cavity (212), and discharge holes of the plurality of discharge pipes (230) correspondingly communicate with the plurality of dry pulverized coal channels one by one;

preferably, the distance between the feed inlet of the discharge pipe (230) and the upper surface (221) of the fluidization plate (220) in the vertical direction is less than or equal to a second preset value and greater than or equal to a third preset value;

preferably, the periphery of the fluidization plate (220) is connected with the side wall surface of the accommodating cavity (211), a plurality of through holes are arranged on the fluidization plate (220), the dry coal powder cavity (212) is communicated with the fluidization cavity (213) through the plurality of through holes, and more preferably, the fluidization plate (220) is a sintered metal plate.

16. A system according to claim 15, wherein the upper surface (221) of the fluidization plate (220) has a beveled portion with an outer edge below an inner edge of the beveled portion, preferably opposite the first portion of the plurality of discharge pipes (230) in a medial-lateral direction;

more preferably, the upper surface (221) of the fluidization plate (220) is a conical surface, preferably, the fluidization plate (220) comprises a conical portion (222) and a cylindrical portion (223), the lower surface of the conical portion (222) is connected with the upper surface of the cylindrical portion (223), wherein the peripheral surface of the cylindrical portion (223) is connected with the side wall surface of the accommodating cavity (211), and the peripheral surface of the conical portion (222) forms the inclined surface portion;

more preferably, the fluidization plate (220) includes a circular table portion and a cylindrical portion, a lower surface of the circular table portion being connected to an upper surface of the cylindrical portion, wherein a circumferential surface of the cylindrical portion is connected to a side wall surface of the accommodation chamber, and a circumferential surface of the circular table portion constitutes the inclined surface portion;

preferably, the included angle between the inclined plane part and the horizontal plane is less than or equal to 20 degrees, and more preferably, the included angle between the inclined plane part and the horizontal plane is less than or equal to 15 degrees.

17. A method of performing dry coal fines gasification in the system of any one of claims 1-16, the method comprising:

s1, respectively introducing a gasifying agent and dry pulverized coal into a gasification unit (2) through a flat flame type gasification burner (21), enabling the gasifying agent and the dry pulverized coal to collide in a gasification chamber (22) of the gasification unit (2) and ignite to form flat flame, and enabling the gasifying agent and the dry pulverized coal to generate gasification reaction to generate crude synthesis gas and molten slag;

s2, cooling the crude synthesis gas and the slag in the first heat exchange unit (23) to obtain a first crude synthesis gas and the cooled slag, and generating steam as a byproduct;

18. A method according to claim 17, wherein the number of clusters of flames formed after collision and ignition is equal to the number of burner units (25), and the length of each cluster of flames is 5-30 times the distance CP of the collision point from the end face of the burner unit (25), and the diameter is 2-3 times, preferably 2 times the distance OC of the gasifying agent flow to the dry pulverized coal flow at the end face of the burner unit (25).

19. The method of claim 18, wherein the gasifying agent stream and the coal dust stream are impinged at an angle α of greater than 0 degrees to less than 90 degrees, preferably 15 degrees to 45 degrees, and most preferably 30 degrees;

preferably, at the outlet of the burner unit (25), the velocity of the gasification agent flow is 2-10 times the velocity of the dry coal powder flow.

20. The method according to any one of claims 17-19, further comprising subjecting the first raw synthesis gas to dust removal by a dust removal unit (8) and then to washing by a washing unit (6);

preferably, the dedusting process is carried out at 500-850 ℃.

21. The method of any one of claims 17-20, wherein the gasification reaction conditions comprise: the reaction pressure is 0-4.0MPa, and the reaction temperature is 1200-1500 ℃;

preferably, the temperature of the first crude synthesis gas is 600-750 ℃, and the temperature of the clean synthesis gas is 100-200 ℃;

preferably, the pressure of the byproduct steam in S2 is 3.3-5 MPa.