CN111349462A

CN111349462A - Entrained-flow bed gasification system and method for coal water slurry

Info

Publication number: CN111349462A
Application number: CN201811584099.9A
Authority: CN
Inventors: 方薪晖; 彭宝仔; 刘臻; 索娅; 冯子洋; 李烨; 安海泉
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: CN111349462B

Abstract

The invention relates to the technical field of coal gasification, and discloses an entrained flow bed gasification system and method for coal water slurry. The system comprises: the device comprises a material conveying unit (1), a gasification unit (2), a second heat exchange unit (3) 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 coal water slurry 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 the coal water slurry, 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 coal water slurry

Technical Field

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

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).

CN104017606A discloses a coal water slurry gasification process system. The coal water slurry gasification process system comprises: a gasification unit comprising a coal gasifier; the heat recovery unit comprises a heat exchanger and a cooling device, wherein an air inlet of the heat exchanger is connected with a first air outlet of the coal gasifier, an air inlet of the cooling device is connected with an air outlet of the heat exchanger, the heat exchanger and the cooling device are respectively provided with a heat exchange tube, a cooling medium is communicated in the heat exchange tubes of the heat exchanger and the cooling device, and the cooling medium recovers heat carried by synthesis gas flowing through the heat exchanger and the cooling device. The system mainly solves the problem of heat recovery in the coal water slurry gasification process, and does not describe the characteristics of a burner of the gasification process, wherein the burner is generally understood to be a single burner in this case. 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.

CN107151567A discloses a coal water slurry gasification system and a process thereof, relating to the technical field of coal gasification. The system comprises a gasification unit, a gasification furnace and an ash lock hopper, wherein the gasification unit comprises the gasification furnace and the ash lock hopper; the gasifier comprises a lower section main reaction zone, an upper section auxiliary reaction zone and an ash chilling chamber which are communicated, and the ash chilling chamber is connected with an ash lock hopper; the separation unit comprises a cyclone separator and a first ash collecting tank; the heat recovery unit comprises a coal gas waste boiler, a steam drum and a second ash collecting tank; the steam drum is communicated with a tube nest in the waste gas boiler; the gas outlet of the cyclone separator is communicated with the gas inlet of the waste gas boiler; the waste gas boiler is provided with an exhaust port; one part of the superheated steam generated by the coal gas waste boiler is introduced into the inlet of the upper two-section auxiliary reaction zone, and the other part of the superheated steam is communicated with the outside. Because the process adopts a water chilling mode to chill and deashing the crude synthesis gas, the process still has the defects of high water consumption and low heat utilization efficiency.

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 coal water slurry by using the same.

The inventor of the invention invents an entrained flow bed gasification system and a method of coal water slurry 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 coal water slurry from a material conveying unit through 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 coal water slurry, the coal water slurry 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 temperature reduction through a heat exchange unit to generate a byproduct steam, the byproduct steam enters a steam unit, the residual steam is conveyed to other downstream processes except for the requirements 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 a coal water slurry entrained flow gasification system, 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 coal water slurry into the gasification chamber, and the coal water slurry 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 second heat exchange unit is communicated with the gasification unit and used for receiving the first crude synthesis gas from the gasification unit, exchanging heat and cooling the first crude synthesis gas to obtain a second crude synthesis gas and byproduct steam; and

the steam unit is communicated with the water inlets and the water outlets of the first heat exchange unit and the second heat exchange unit respectively, and can perform centralized treatment and distribution on water entering the first heat exchange unit and the second heat exchange unit and byproduct steam;

the flat flame type gasification burner comprises a plurality of burner units arranged at the top of the gasification unit, the gasification agent and coal water slurry can collide in the gasification chamber and be ignited to form flat flame by the flat flame type gasification burner, 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 gasifying a coal-water slurry in the system according to the first aspect of the present invention, the method comprising:

s1, respectively introducing a gasifying agent and the coal water slurry into a gasification unit through a flat flame type gasification burner, enabling the gasifying agent and the coal water slurry to collide in a gasification chamber of the gasification unit and ignite to form flat flame, and enabling the gasifying agent and the coal water slurry 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 to obtain a first crude synthesis gas and the cooled slag, and generating steam as a byproduct;

s3, cooling the first crude synthesis gas in the second heat exchange unit to obtain a second crude synthesis gas and byproduct steam;

s4, collecting the steam by-produced in the step S3 and the step S4 and the heat exchange medium used for heat exchange for centralized disposal 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 structural view of a dispenser according to an embodiment of the present invention.

Description of the reference numerals

1. Material conveying unit 2, gasification unit 3 and second heat exchange unit

4. Steam unit 5, slag water treatment unit 6 and washing unit

7. Wastewater treatment unit 8, dust removal unit 12 and water-coal slurry tank

20 high-pressure coal slurry pump 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. Coal water slurry distribution and transportation 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. Dispensing member 150, separator

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.

In the present invention, unless explicitly stated, neither "first" nor "second" represent a sequential order, but merely to distinguish, for example, the "first" and "second" in "first raw synthesis gas" and "second raw synthesis gas" merely to distinguish that these are two different streams.

As previously mentioned, a first aspect of the present invention provides a coal water slurry entrained flow gasification 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 coal water slurry into the gasification chamber 22, and the coal water slurry 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 second heat exchange unit 3 is communicated with the gasification unit 2, and the second heat exchange unit 3 receives the first crude synthesis gas from the gasification unit 2, exchanges heat and cools the first crude synthesis gas to obtain a second crude synthesis gas and byproduct steam; and

the steam unit 4 is communicated with the water inlets and the water outlets of the first heat exchange unit 23 and the second heat exchange unit 3 respectively, and can perform centralized treatment and distribution on water entering the first heat exchange unit 23 and the second heat exchange unit 3 and by-product 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 coal water slurry 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 impact and mixing of the coal water slurry and the gasifying agent outside the ports of the burner unit 25, the formed impact points are substantially positioned on the same plane, the number of clusters of flames formed after the impact and the 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 can be formed by controlling the distance CP between the impact point and the end surface of the flat flame type gasification burner 21 and the distance OC between the flow of the gasification agent and the flow of the water-coal slurry at the end surface of the burner unit 25.

In the present invention, preferably, the burner unit 25 includes at least one coal water slurry channel and at least one gasifying agent channel, and a distance CP between an impact point of the coal water slurry 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 coal water slurry flow at the end surface of the burner unit 25.

As shown in fig. 4 and 5, the coal-water slurry channel is disposed in the center of the

burner unit

25, and 3 gasifying agent channels are disposed around the coal-water slurry channel, and the distance OC from the gasifying agent flow to the coal-water slurry flow at the end surface of the burner unit 25 refers to the distance from the intersection point of the center line of the coal-water slurry channel and the end surface to the intersection point of the center line of the gasifying agent channel and the end surface.

According to an embodiment of the present invention, the coal-water slurry 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 coal-water slurry channel is an annular channel enclosing the gasifying agent channel at the center, the gasifying agent flow is ejected vertically and downwardly, and the annular coal-water slurry flow can be ejected inwardly and downwardly, for example, in the shape of 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 water-coal slurry 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.

The entrained-flow gasification system for coal water slurry provided by the first aspect of the 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 second heat exchange unit 3, 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 gasifying agent from the gasifying agent pipeline and the coal water slurry from the material conveying unit 1 are impacted and mixed outside the port of the burner unit 25, and gasification reaction is carried out in the gasification chamber 22, so as to generate products such as crude synthesis gas and slag. 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 invention, the impact mixing means that the coal water slurry and the gasifying agent enter the burner unit 25 through different pipelines and impact and mix outside the port of the burner unit 25, that is, the coal water slurry and the gasifying agent do not mix and then enter the burner unit 25, and the coal water slurry and the gasifying agent do not mix in any form in the burner unit 25.

The second heat exchange unit 3 is communicated with the first heat exchange unit 23 and is used for exchanging heat for the first crude synthesis gas to obtain a second crude synthesis gas and byproduct steam.

Preferably, the temperature of the second crude synthesis gas is 200-300 ℃, and the pressure of the byproduct steam of the second heat exchange unit 3 is 3.3-5 MPa.

According to a preferred embodiment of the present invention, the second heat exchange unit 3 can exchange heat with other medium, such as coal gas (H) by indirect heat exchange with coal slurry, or by using high pressure steam as a byproduct of waste heat boiler convection, according to actual needs₂、CO、CH₄Etc.), the inner shell of the heat exchanger is high-pressure synthesis gas, and the outer shell is normal-pressure coal slurry, thereby improving the yield of the synthesis gas.

The washing unit 6 is communicated with the second heat exchange unit 3 and is used for washing the second crude 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 second 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, the water inlet (or steam inlet) and the water outlet (or steam outlet) of the first heat exchange unit 23 and the second heat exchange unit 3, and is used for centralized treatment and distribution of the cooling medium (water) of the gasification chamber 22, the first heat exchange unit 23 and the second heat exchange unit 3, and the byproduct steam, and the redundant steam can be used by the system or a downstream process.

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 (such as steam) discharged by the first heat exchange unit 23; the water inlet (or steam inlet) of the second heat exchange unit 3 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 heat of the heat exchange medium (such as steam) can be absorbed by the steam unit 4. 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 second heat exchange unit 3. Further preferably, the dust removal unit 8 is communicated with the first heat exchange unit 23 and the second heat exchange unit 3, so that the raw synthesis gas leaving the gasification unit 2 enters the second heat exchange unit 3 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 coal water slurry channel, and the coal water slurry channel can be positioned at the central position and can also be arranged at the periphery of the gasifying agent channel around the gasifying agent channel, namely, the coal water slurry material flow can be enclosed by the gasifying agent airflow, and the gasifying agent material flow can also be enclosed by the coal water slurry material flow. For example, the burner unit 25 includes: the coal water slurry gasification device comprises a coal water slurry channel and a plurality of gasification agent channels arranged around the coal water slurry channel; or one gasifying agent channel and a plurality of coal water slurry channels arranged around the gasifying agent channel. The coal-water slurry passage and the gasifying agent passage may also be coaxially arranged, for example, the burner unit 25 includes: a coal water slurry channel arranged in the center of the burner unit 25 and an annular gasifying agent channel arranged around the coal water slurry channel; or a gasifying agent channel arranged in the center of the burner unit 25 and an annular water-coal-slurry channel arranged around the gasifying agent channel. However, no matter what the arrangement mode is, it is required that each burner unit 25 can collide the coal water slurry and the gasifying agent at a certain distance outside the end face of the burner unit 25 and burn the coal water slurry and the gasifying agent, so that the collision points of the coal water slurry and the gasifying agent of each burner unit 25 are substantially located on the same plane to form the flat flame.

In order to better achieve the above object, as shown in fig. 4 and 5, the formation of the flat flame preferably includes controlling an included angle α between center lines of the coal-water slurry passage and the gasifying agent passage in the burner unit 25 to be greater than 0 degree and less than 90 degrees, preferably 15 degrees and 45 degrees, and most preferably 30 degrees, and more preferably, the speed of the gasifying agent flow at the outlet of the burner unit 25 is 2 to 20 times, preferably 5 to 15 times, the speed of the coal-water slurry.

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 coal water slurry (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 minute more of the coal water slurry 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 distribution holes 121 are communicated with the coal water slurry channels in a one-to-one correspondence manner. In other words, the number of distribution holes 121 is equal to the number of coal-water slurry passages, and one distribution hole 121 communicates with one coal-water slurry passage.

The coal-water slurry channel and the gasifying agent channel can form one burner unit 25, so that the flat-flame gasification burner 21 of the invention is provided with a plurality of burner units 25, namely, the flat-flame gasification burner 21 of the invention can integrate a plurality of burner units 25 together.

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 coal water slurry channel is more than 15 degrees and less than 45 degrees, each gasifying agent channel is neither vertical to nor parallel to the corresponding coal water slurry channel. Therefore, the oxygen-containing gasifying agent injected from each gasifying agent channel and the coal water slurry injected from the corresponding coal water slurry channel 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 coal water slurry can be mixed and dispersed more quickly and uniformly, and the gasification reaction rate can be increased. Moreover, since the coal-water slurry and the oxygen-containing gasifying agent are supplied into the gasification chamber through the plurality of burner units 25, the oxygen-containing gasifying agent and the coal-water slurry can be mixed more quickly and more uniformly, so that 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 water-coal slurry flow and the speeds of the gasifying agent flow and the water-coal slurry flow, the width and the length of flame which is combusted downwards after the gasifying agent flow and the water-coal slurry flow collide can be adjusted, slag adhering is ensured, and meanwhile, the explosion type flame is prevented from damaging the inner wall of the gasification chamber. The flame cluster formed by fully mixing a plurality of strands of gasifying agent flows and water-coal slurry flows downwards while burning, so that the water-coal slurry flows in each flame burn more fully, and further the reaction rate is obviously improved.

Because the gasifying agent channel is positioned in the coal water slurry 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 coal water slurry provided by the coal water slurry channel, thereby enabling the temperature distribution of the high-temperature area of the gasification chamber to be more uniform, namely enabling the temperature distribution near the flat-flame type gasification burner 21 to be more uniform.

Moreover, by arranging the distributor 100, the coal water slurry can be uniformly delivered into the gasification chamber only by arranging a delivery pipeline for delivering the coal water slurry to the flat flame type gasification burner 21, so that the investment cost (investment of equipment and a monitoring system of the delivery pipeline) and the operation cost of delivering the coal water slurry can be greatly reduced. Therefore, by arranging the distributor 100, the coal water slurry can be provided for a plurality of coal water slurry channels under the condition of not increasing investment cost and operation cost, so that a plurality of burner units 25 are arranged 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 coal-water slurry 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 inlet 111 to the discharge outlet 112 is the flowing direction of the coal water slurry.

The coal water slurry 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. The contraction section 113 is used for accelerating the coal-water slurry material flow, the uniform cross section 114 is used for stabilizing the speed field of the coal-water slurry material flow so as to avoid uneven distribution of the coal-water slurry material flow at the downstream due to large fluctuation of the flow of the coal-water slurry material flow, and the expansion section 115 is used for evenly distributing the coal-water slurry material flow at each distribution hole 121 according to the speed inertia.

That is to say, the coal-water slurry stream accelerates in the contraction section 113, enters the expansion section 115 after passing through the constant-cross-section 114 and enters the plurality of coal-water slurry branch conveying pipelines 30 through the plurality of distribution holes 121, so as to realize the uniform distribution of the coal-water slurry stream.

According to the invention, the distributor 100 is provided with the contraction section 113, the constant section 114 and the expansion section 115 which are sequentially connected, so that the velocity field of the coal water slurry material flow can be stabilized, and the coal water slurry material flow can be uniformly distributed into the distribution holes 121 according to the velocity inertia.

According to the present invention, the flat flame type gasification burner 21 can uniformly distribute the coal water slurry 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 invention, the flat flame type gasification burner 21 can uniformly distribute the coal water slurry material flow into a plurality of coal water slurry channels which are communicated with a plurality of distribution holes 121 in a one-to-one correspondence manner by arranging the distributor 100. Therefore, the coal water slurry can be uniformly conveyed into the gasification chamber only by arranging a coal water slurry main conveying pipeline for conveying the coal water slurry to the distributor 100 (the coal water slurry main conveying pipeline can be connected with the feeding hole 111 of the main pipe 110 of the distributor 100), so that the investment cost (the investment of equipment and a monitoring system of a conveying pipeline) and the operation cost of the coal water slurry conveying can be greatly reduced. That is, when the flat-flame type gasification burner 21 has a plurality of burner units 25, N-1 delivery pipes for delivering the coal water slurry to the burner units 25 and a monitoring system for monitoring the delivery 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 coal water slurry main conveying pipe by a flange, a ferrule, welding or other connection means. The inner diameter of the joint of the main pipe 110 can be the same as that of the main coal-water slurry conveying pipeline, and the part of the main coal-water slurry conveying pipeline adjacent to the main pipe 110 can keep a straight pipe state so as to avoid sudden change of pipeline resistance. The main coal-water slurry transport conduit may be connected to a high pressure coal slurry pump 20.

The distribution holes 121 can be connected with the water-coal-slurry pipes through the water-coal-slurry branch conveying pipes 30 in a one-to-one correspondence manner. That is, the coal-water slurry may exit the distributor 100 through a plurality of distribution holes 121 located at the discharge port 112.

Therefore, the coal water slurry is distributed by the distributor 100 and uniformly distributed into the coal water slurry branch conveying pipelines 30, and then enters the coal water slurry channels through the coal water slurry branch conveying pipelines 30.

Specifically, each coal-water slurry distribution pipe 30 may be connected to the cover plate 120 by a flange, a ferrule, a weld, or other connection means. The plurality of coal-water slurry distribution pipes 30 may be symmetrical with respect to the 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 larger 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 larger than the cross-sectional area of the main coal-water-slurry conveying pipe, the sum of the cross-sectional areas of the plurality of sub-coal-slurry conveying pipes 30 may be equal to or larger than the cross-sectional area of the main coal-water-slurry conveying pipe, and the sum of the cross-sectional areas. The cross-sectional area of the feed port 111 is equal to or greater than the cross-sectional area of the main coal-water slurry conveying pipeline.

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 coal-water-slurry conveying pipe, the sum of the cross-sectional areas of the plurality of sub-coal-slurry conveying pipes 30 is equal to the cross-sectional area of the main coal-water-slurry conveying pipe, and the sum of the cross-sectional areas of the plurality of sub-coal. The cross-sectional area of the feed port 111 is equal to the cross-sectional area of the main coal-water slurry 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 coal-water slurry flow in the main pipe 110 with the purge gas, not only can the coal-water slurry flow be prevented from accumulating on the inner wall of the main pipe 110, but also the coal-water slurry flow near the wall surface of the main pipe 110 can be accelerated so as to make the flow of the coal-water slurry flow in the main pipe 110 approach to the piston flow, and particularly make the coal-water slurry flow approach to the piston flow distribution in the constant cross section 114 and the expansion section 115.

That is, by externally covering the purge pipe 130 on the main pipe 110, it is possible to prevent clogging or unstable flow of the coal-water slurry stream due to accumulation of the coal-water slurry stream on the wall surface of the main pipe 110, and to accelerate the coal-water slurry stream 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 cross-section 114, and the lower end of the purge tube 130 may be flush with the lower end of the constant cross-section 114, so as to purge the entire flow of coal-water slurry within the constant cross-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 coal water slurry material flows through the main pipe 110 (the pressure jump easily causes the accumulation and blockage of the coal water slurry material flow) 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. A plurality ofThe purge gas inlets 132 may be provided on the purge pipe 130 at equal intervals in the circumferential direction of the purge pipe 130, and 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 used for conveying the coal water slurry 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 after the coal water slurry is gasified 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 the coal water slurry into the distribution holes 121 more uniformly and further into the coal water slurry distribution and transportation pipelines 30, and the coal water slurry distribution and transportation pipelines 30 are respectively communicated with the coal water slurry 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 the 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 coal-water-slurry stream flowing therethrough so as to divide the coal-water-slurry stream. The distribution member 140 can distribute the coal water slurry along the annular space, thereby avoiding the distribution difference caused by the uneven distribution of the coal water slurry at the axial center of the main pipe 110 and near the wall surface (especially at the axial center of the expanding section 115 and near the wall surface). 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. Thereby, the coal water slurry material flow can be better split, and the coal water slurry material flow can be more uniformly distributed along the ring system space. 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 center line of the distribution member 140 is adjacent to the center line of the main pipe 110, so that the coal-water slurry flow can be divided along the center line adjacent to the main pipe 110, and the coal-water slurry flow can be distributed along the ring system space more uniformly.

Preferably, the centerline of the distribution member 140 coincides with the centerline of the main tube 110. Therefore, the coal water slurry flow can be divided along the central line of the main pipe 110, so that the coal water slurry flow can be distributed along the ring system space more uniformly.

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 arranging the partition 150 between two adjacent distribution holes 121, the partition 150 can be multiple, and the multiple partitions 150 can be arranged at equal intervals along the circumferential direction of the main pipe 110, so that not only can the coal water slurry be primarily distributed by the partition 150, but also the flow of the coal water slurry flowing to each distribution hole 121 can be limited, and the fluctuation of the flow of the coal water slurry flowing to the distribution holes 121 caused by the mixed flow of the coal water slurry along the tangential direction of the main pipe 110 (the expansion section 115) can be reduced.

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.

Therefore, the distribution member 140 and the partition member 150 can better and more uniformly perform primary distribution on the coal water slurry, and the partition member 150 can better limit the flow of the coal water slurry flowing to each distribution hole 121, so as to further reduce the flow fluctuation of the coal water slurry flowing to the distribution holes 121 caused by the mixed flow of the primarily distributed coal water slurry along the tangential direction of the main pipe 110 (the expansion 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 periphery of the distribution hole 121 higher than the distribution hole 121, thereby preventing the coal water slurry from accumulating around the distribution hole 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, the coal-water slurry can be further prevented 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. The coal water slurries (as shown in fig. 7) from the material conveying unit 1 are respectively conveyed to the corresponding burner units 25. That is, one minute more of the coal water slurry is completed in the material transporting unit 1.

According to the invention, the system preferably further comprises a material conveying unit 1, wherein the material conveying unit 1 is used for conveying the coal water slurry to a gasification unit 2.

Preferably, the pressure in the gasification chamber 2 is 4.0MPa, so that the coal water slurry needs to be pressurized and conveyed in the material conveying unit 1, and therefore, a high-pressure coal slurry pump 20 is preferably arranged at the outlet of the coal water slurry tank 12.

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.

As shown in fig. 6, if the feeding manner of the flat flame type gasification burner 21 is to uniformly feed all burner units 25, coal dust, water and additives are used as raw materials and uniformly mixed in the water-coal slurry tank 12 to form water-coal slurry, the water-coal slurry tank 12 is provided with only one outlet, and a high-pressure coal slurry pump 20 is arranged at the outlet of the water-coal slurry tank 12 and is used for delivering the water-coal slurry to the flat flame type gasification burner 21. In order to form a water-coal-slurry flow corresponding to the plurality of burner units 25 in the flat-flame type gasification burner 21, a water-coal-slurry flow in the water-coal-slurry tank 12 is first fed to the distributor 100 in the flat-flame type gasification burner 21 by the high-pressure coal-slurry pump 20, and then the distributor 100 divides the water-coal-slurry flow into a plurality of water-coal-slurry flows, so that the plurality of formed water-coal-slurry flows have a plurality of discharge ports corresponding to the number of the burner units 25, and the plurality of water-coal-slurry flows enter the corresponding burner units 25 through the respective discharge ports. On the other hand, as shown in fig. 7, if the feeding mode of the flat flame type gasification burner 21 is independent for each burner unit 25, coal dust, water and additives as raw materials are uniformly mixed in the water-coal slurry tank 12 to form water-coal slurry, the water-coal slurry tank 12 is provided with a plurality of discharge ports corresponding to the number of the burner units 25, and each discharge port is provided with a high-pressure coal slurry pump 20 for conveying the water-coal slurry flows from each discharge port to the burner units 25 in a one-to-one correspondence manner.

According to the invention, the coal-water slurry has an average residence time t in the gasification chamber 22 provided with a single nozzle, with the same volume of the gasification chamber_m4.41s, and 72.54% of the coal water slurry flow leaves 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 average residence time t of the coal-water slurry 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 coal-water slurry stream leaves 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 distribution of residence time of the material flow, a higher mixing efficiency, and a larger residence time for the same volume of the gasification chamber. 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 the coal water slurry into the gasification unit 2 through a flat flame type gasification burner 21, enabling the gasifying agent and the coal water slurry 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 coal water slurry 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;

s3, cooling the first crude synthesis gas in the second heat exchange unit 3 to obtain a second crude synthesis gas and byproduct steam;

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 performing secondary convective heat exchange after dedusting the first crude synthesis gas; further preferably, the dedusting process is carried out at 500-850 ℃.

In the present invention, the choice of the gasifying agent is not particularly limited, and may be a gasifying agent known in the art and used for gasifying coal water slurry, and may be, for example, oxygen and/or air.

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 crude 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 gasifying coal-water slurry in the system according to the first aspect of the present invention is described in detail below with reference to fig. 1 to 7.

The coal water slurry is conveyed to the material conveying unit 1, is generally formed by uniformly mixing coal dust, water and additives serving as raw materials in a coal water slurry tank 12, and is conveyed to the gasification unit 2 by a high-pressure coal slurry pump 20 to be output. The one or more streams of water-coal slurry leaving the material transfer unit 1 are then passed through a flat-flame type gasification burner 21 together with one or more streams of gasification agent 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 water-coal-slurry flow and the corresponding gasification agent flow can collide violently in the gasification chamber 22, and the collision can cause the water-coal-slurry and the gasification agent to be ignited immediately and form the flat flame which is called by 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, enters the second heat exchange unit 3 after dust removal to exchange heat with water in the second heat exchange unit 3 to obtain the second crude synthesis gas with the temperature of 200-300 ℃, and the water in the second heat exchange unit 3 is heated and converted into steam to be output.

The second raw synthesis gas is then introduced into a scrubbing unit 6, in which scrubbing unit 6 solid particles entrained in the second raw synthesis gas are moistened by washing with water and separated from the synthesis gas to form a precipitate at the bottom of the column, and clean synthesis gas moves upwards and is withdrawn from 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, the inlet water of the first heat exchange unit 23 and the inlet water of the second heat exchange unit 3 are both from the steam unit 4, the water is heated in the first heat exchange unit 23 and the second heat exchange unit 3 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 inlet water from outside the system for the first heat exchange unit 23, the second heat exchange unit 3 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 of the in-system or downstream processes on the steam.

According to the entrained flow bed gasification system and method of the coal water slurry, the characteristics of high gasification reaction speed, short reaction residence time and high process heat are combined with the flat flame type gasification technology, the volume and the structural complexity of the gasification reactor are not basically increased while the process heat of the gasification reaction is reasonably utilized through the first heat exchange unit, the second heat exchange unit and the steam unit, and slag water, grey water and chilled 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 heating + second heat exchange unit heating)/coal water slurry calorific value; the gas calorific value (MJ) is obtained by calculating the composition calorific value of the synthesis gas.

The coal slurry concentration of the coal water slurry used in the following examples and comparative examples was 62%.

Example 1

In this example, referring to fig. 1, table 1 shows coal quality analysis data of the coal water slurry 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 coal water slurry channel arranged in the center and 3 gasification agent channels arranged around the coal water slurry 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 coal water slurry outlet is 12.5 mm; the speed of the coal water slurry leaving the burner unit is 12m/s, and the speed of the gasifying agent leaving the burner unit is 150 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 taken as a gasification agent to be collided and mixed with coal water slurry 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 enters a second heat exchange unit 3 for secondary convection heat exchange to obtain a second crude synthesis gas, and the second crude synthesis gas 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 ℃, the temperature of the second crude synthesis gas is 250 ℃, 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 which is a byproduct of the water-cooled wall, the primary radiation heat exchange and the secondary convection heat exchange in 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 coal water slurry 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 method of this comparative example are the same as example 1 except that the gasification unit is provided with an overhead burner unit comprising a water-coal-slurry channel centrally disposed and a gasifying agent channel coaxially disposed with the water-coal-slurry channel.

Table 1 shows the coal quality analysis data of the coal water slurry 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 the method of the comparative example are the same as those of the embodiment 1, except that three burner units are arranged at the top of the gasification unit, each burner unit comprises a water-coal-slurry channel arranged in the center and a gasification agent channel coaxially arranged with the water-coal-slurry channel, and the water-coal-slurry sprayed by the three burner units and the gasification agent collide with each other on the axis of the gasification unit.

Comparative example 3

The system and method of the comparative example are the same as example 4, except that 10 burner units which are parallel to each other are arranged at the top of the gasification unit, and each burner unit comprises a water-coal-slurry channel arranged in the center and a gasification agent channel which is coaxial with the water-coal-slurry channel.

Table 1 shows the coal quality analysis data of the coal water slurry 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

The results in table 2 show that when the flat flame entrained flow coal gasification system and the gasification method thereof are used for gasifying coal water slurry, the thermal efficiency of the system can reach 83.1 percent, 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 coal water slurry, 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 coal water slurry into the gasification chamber (22), and the coal water slurry 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 second heat exchange unit (3) is communicated with the gasification unit (2), and the second heat exchange unit (3) receives the first crude synthesis gas from the gasification unit (2) and performs heat exchange and temperature reduction on the first crude synthesis gas to obtain a second crude synthesis gas and byproduct steam; and

the steam unit (4) is communicated with the water inlets and the water outlets of the first heat exchange unit (23) and the second heat exchange unit (3) respectively, and can perform centralized treatment and distribution on water entering the first heat exchange unit (23) and the second heat exchange unit (3) and by-product 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 coal water slurry 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.

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

3. The system of claim 2, wherein the angle α at which the gasification agent flow impinges with the water coal slurry flow is 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:

the coal water slurry gasification device comprises a coal water slurry channel and a plurality of gasification agent channels arranged around the coal water slurry channel; or

The coal water slurry gasification device comprises a gasification agent channel and a plurality of coal water slurry channels arranged around the gasification agent channel.

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

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

A gasifying agent channel arranged in the center of the burner unit (25) and an annular water-coal-slurry 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 the second heat exchange unit (3) and is used for washing the second 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 second heat exchange unit (3) and is used for enabling the first crude synthesis gas to enter the second heat exchange unit (3) for heat exchange 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 coal water slurry 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 one of claims 1-8, wherein the system further comprises a material conveying unit (1), the material conveying unit (1) being adapted to convey the coal-water slurry to a gasification unit (2);

preferably, the material conveying unit (1) comprises a water-coal slurry tank (12) and a high-pressure slurry pump (20), wherein each outlet of the water-coal slurry tank (12) is provided with the high-pressure slurry pump (20).

15. A method of gasifying a coal water slurry in the system of any one of claims 1 to 14, the method comprising:

s1, respectively introducing a gasifying agent and the coal water slurry into a gasification unit (2) through a flat flame type gasification burner (21), enabling the gasifying agent and the coal water slurry 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 coal water slurry 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 the cooled slag, and generating steam as a byproduct;

s3, cooling the first crude synthesis gas in the second heat exchange unit (3) to obtain a second crude synthesis gas and byproduct steam;

16. A method according to claim 15, 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 water-coal-slurry flow at the end face of the burner unit (25).

17. The method of claim 16, wherein the angle α at which the gasification agent stream impinges with the water coal slurry stream is 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 to 20 times, preferably 5 to 15 times, the velocity of the water-coal slurry flow.

18. The method according to any of the claims 15-17, further comprising de-dusting the first raw synthesis gas before cooling the first raw synthesis gas in the second heat exchange unit (3);

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

19. The method of any one of claims 15-18, 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 ℃, the temperature of the second crude synthesis gas is 200-300 ℃, and the temperature of the clean synthesis gas is 100-200 ℃;

preferably, the pressure of the byproduct steam in S2 and S3 is 3.3-5MPa independently.