Coal medium gradient utilization coupling gasification system
By combining the cascade utilization method of circulating fluidized beds and airflow beds, the problem of the reduction in reactivity of the intermediate coke powder in traditional coal is solved, efficient utilization of coke powder and cost reduction are achieved, and the overall utilization efficiency of coal is improved.
Patent Information
- Application Number
- CN202323246556.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-27
- Publication Date
- 2025-01-10
- Estimated Expiration
- 2033-11-27
AI Technical Summary
During the traditional coal utilization process, the decrease in reactivity of coke powder leads to increased energy losses and investment, and traditional circulating fluidized beds cannot effectively regulate material reactions.
The coal medium cascade utilization coupled gasification system is adopted, combined with the circulating fluidized bed and the airflow bed, and the utilization efficiency of coke powder is improved through the cascade utilization method. A cyclone separator and returner are set up between the circulating fluidized bed and the airflow bed to realize coke The powder is reused and the reactivity is adjusted by a screw feeder.
It greatly reduces the waste of coke powder, reduces the investment cost of raw material abrasive system, improves the utilization efficiency and reactivity of coke powder, and reduces energy losses.
Smart Images
Figure CN222331854U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of energy conservation and environmental protection, and more specifically to a coal medium cascade utilization coupled gasification system. Background Art
[0002] For a long time, my country's energy characteristics have been rich in coal, poor in oil, and little gas, so the clean and efficient use of coal has become an important issue at present. In my country, a large amount of coal coke powder is produced every year during the use of coal. Due to the coking process, the volatile components in these coal coke powders are completely precipitated, and the small pores in the coke powder are blocked, which reduces the chance of contact with gasification agents or oxygen, resulting in a decrease in the reactivity of the coke powder and an increase in the reaction time, so that it cannot be used efficiently.
[0003] In order to ensure solid slag discharge, the reaction temperature of traditional fluidized bed gasifiers is generally 850-1000℃. At this temperature, the gasification rate of coke powder is slow, and it is difficult to fully react in a short time, which leads to the ineffective utilization of coke powder. As for the gasification of fluidized bed gasifiers, its characteristics are that the high reaction temperature is conducive to gasification, but there are requirements for the particle size of the raw materials, which is generally around 0-90μm. If a grinding system is added alone, the investment and energy consumption will increase greatly. Therefore, how to combine the advantages of fluidized bed gasification and fluidized bed gasification, improve the conversion rate of coke powder, and reduce energy loss is an important solution. In addition, the traditional circulating fluidized bed only has one raw material inlet, which can only provide a single material for the circulating fluidized bed, and cannot pass different materials to adjust the reaction of the material. Utility Model Content
[0004] In response to at least one problem in the prior art, the present solution provides a coupled gasification system for cascade utilization of coal media, which combines circulating fluidized bed gasification and entrained flow gasification and adopts a cascade utilization method to improve the utilization efficiency of the coal medium. The circulating fluidized bed connects the first feeder and the second feeder to improve the reaction efficiency of the raw materials.
[0005] In order to achieve the above-mentioned purpose, the technical solution provided by the utility model is:
[0006] A coal medium cascade utilization coupled gasification system comprises a feeding unit, a circulating fluidized bed and an entrained fluidized bed, wherein the feeding inlet of the entrained fluidized bed is connected to the coal gas outlet of the circulating fluidized bed, the feeding unit comprises a first feeder and a second feeder for feeding the circulating fluidized bed, the first feeder is used for conveying raw coal, and the second feeder is used for conveying coke powder or semi-coke powder.
[0007] Furthermore, a cyclone separator is connected between the circulating fluidized bed and the entrained bed, a coal gas outlet of the cyclone separator is communicated with the entrained bed, and a coal slag outlet of the cyclone separator is communicated with the circulating fluidized bed.
[0008] Furthermore, a material return device is connected between the coal slag outlet of the cyclone separator and the circulating fluidized bed.
[0009] Furthermore, a fly ash collection unit is connected between the coal gas outlet of the cyclone separator and the fluidized bed.
[0010] Furthermore, the fly ash collection unit includes a first dust collector, a fly ash conveying device, a dry powder bin and a feeding tank which are connected in sequence; the first dust collector is connected to a cyclone separator, and the outlet of the feeding tank is connected to the fluidized bed gasification furnace at the top of the fluidized bed.
[0011] Furthermore, a first gas outlet A is also provided on the first dust collector.
[0012] Furthermore, a second gas outlet B is provided on the fluidized bed, and a second dust collector is connected between the fluidized bed and the second gas outlet B.
[0013] Furthermore, the first feeder and the second feeder are screw feeders.
[0014] Furthermore, gasifying agent inlets are provided on both the circulating fluidized bed and the fluidized bed.
[0015] Furthermore, slag outlets are provided directly below the circulating fluidized bed and the entrained fluidized bed.
[0016] Compared with the prior art, the technical solution provided by the utility model has the following beneficial effects: the feed inlet of the fluidized bed is connected to the gas outlet of the circulating fluidized bed, and the small-particle coke particles after the reaction in the circulating fluidized bed are sent to the fluidized bed for secondary utilization, which greatly reduces the waste of coke particles. In addition, the fluidized bed uses small-particle coke particles as raw materials, which reduces the raw material grinding system and greatly saves the investment cost of the system. Combining the characteristics of the circulating fluidized bed and the fluidized bed gasification, the gasification systems of the circulating fluidized bed and the fluidized bed are coupled, and the coke powder is utilized in a step-by-step manner, which improves the utilization efficiency of the coke powder and greatly reduces the utilization cost of the coke powder. The first feeder and the second feeder are arranged on the circulating fluidized bed to adjust the reactivity in the fluidized bed gasifier and facilitate the adjustment of the feeding speed. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the structure of the coupled gasification system for cascade utilization of coal media.
[0018] Description of labels:
[0019] 1. Feeding unit; 11. First storage hopper; 12. Second storage hopper; 13. Third storage hopper; 14. First feeder; 15. Second feeder;
[0020] 2. Circulation and return unit; 21. Circulating fluidized bed; 22. Slag discharge device; 23. Cyclone separator; 24. Return device;
[0021] 3. Fly ash collection unit; 31. First dust collector; 32. Fly ash conveying device; 33. Dry powder bin; 34. Feeding tank;
[0022] 4. Entrained flow bed; 41. Entrained flow bed gasifier; 42. Exhaust device; 43. Second dust collector. DETAILED DESCRIPTION
[0023] In order to further understand the content of the utility model, the utility model is described in detail in conjunction with the drawings and embodiments.
[0024] The terms "installed", "set", "provided with", and "connected" in this embodiment should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0025] like Figure 1 As shown, a coal medium cascade utilization coupled gasification system includes a feeding unit 1, a circulating fluidized bed 21 and an entrained fluidized bed 4. The feeding unit 1 includes a first feeder 14 and a second feeder 15, both of which feed the circulating fluidized bed 21. The first feeder 14 and the second feeder 15 are both screw feeders. Feeding is performed by the screw feeder. The feeding speed to the circulating fluidized bed 21 can be controllably adjusted by adjusting the speed of the screw feeder, thereby realizing low-speed fluidization. In this embodiment, the first feeder 14 is used to transport raw coal. The outlet of the first feeder 14 is connected to the circulating fluidized bed 21, and the inlet is connected to the second storage hopper 12 for storing raw coal. In some cases, in order to play a caching role, a hopper, that is, a third storage hopper 13, is also provided between the second storage hopper 12 and the first feeder 14. The second feeder 15 is used to transport coke powder or semi-coke powder. The outlet of the second feeder 15 is connected to the circulating fluidized bed 21, and the inlet is connected to the first storage hopper 11 for storing coke powder or semi-coke powder.
[0026] The circulating fluidized bed 21 is connected to the first feeder 14 and the second feeder 15, and the coke powder or semi-coke powder material is mainly transported to the circulating fluidized bed 21 through the second feeder 15. In some cases, in order to adjust the reactivity of the coke powder or semi-coke powder in the gasifier of the circulating fluidized bed 21, coal powder can be transported through the first feeder 14 for adjustment.
[0027] The circulating fluidized bed 21 is the core reaction unit of the fluidized bed system, and the reaction temperature therein can be adjusted within the range of 850-1000°C as required. A fluidized bed gasifier is arranged in the circulating fluidized bed 21, and a slag outlet is arranged directly below the circulating fluidized bed 21, and the slag outlet is connected to the slag outlet device 22. The circulating fluidized bed 21 is also provided with a gasifying agent inlet, so that the gasifying agent enters the fluidized bed gasifier to participate in the reaction. The gasifying agent can be pure oxygen, enriched oxygen, air plus steam, etc. as the gasifying agent. The gasifying agent can be preheated in advance before entering the fluidized bed gasifier to save the heat required for the reaction in the furnace.
[0028] A circulating return unit 2 is connected above the circulating fluidized bed 21. The circulating return unit 2 includes a cyclone separator 23. The coal gas outlet of the cyclone separator 23 is connected to the fluidized bed 4, and the coal slag outlet of the cyclone separator 23 is connected to the circulating fluidized bed 21. A return device 24 is also connected between the coal slag outlet of the cyclone separator 23 and the circulating fluidized bed 21. When coke powder or semi-coke powder enters the fluidized bed gasifier to participate in the reaction, a part of the large-particle coke powder is discharged from the furnace through the slag discharge device 22 after a long reaction in the lower part of the furnace of the fluidized bed gasifier. Small-particle coke powder enters the high-temperature cyclone separator 23 from the outlet of the fluidized bed gasifier along with the coal gas for gas-solid separation. The separated coke powder returns to the fluidized bed gasifier through the return device 24 to participate in the reaction again.
[0029] A fly ash collection unit 3 is connected between the gas outlet of the cyclone separator 23 and the fluidized bed 4. The fly ash collection unit 3 includes a first dust collector 31, a fly ash conveying device 32, a dry powder bin 33 and a feed tank 34 which are connected in sequence. The first dust collector 31 is connected to the cyclone separator 23, and the outlet of the feed tank 34 is connected to the fluidized bed gasifier 41 at the top of the fluidized bed 4. The first gas outlet A is also provided on the first dust collector 31. After the gas separated by the cyclone separator 23 enters the fly ash collection unit 3, the first dust collector 31 is first used to cool and remove dust. The first gas after cooling and removing dust is delivered to the user through the first gas outlet A for use. The collected carbon-containing fly ash enters the fly ash conveying device 32 and is delivered to the atmospheric pressure dry powder bin 33 for temporary storage, and then delivered to the fluidized bed 4 through the powder feeding tank 34. In this embodiment, the fly ash conveying device 32 is a continuous pneumatic conveying device.
[0030] The fluidized bed 4 is also provided with a second gas outlet B, and a second dust collector 43 is connected between the fluidized bed 4 and the second gas outlet B. The fluidized bed 4 is provided with a gasifying agent inlet connected to the fluidized bed gasifier 41, and a slag outlet is provided directly below the fluidized bed 4, and the slag outlet is connected to the discharge device 42. The fly ash from the powder feeding tank 34 is transported to the fluidized bed gasifier 41 to participate in the reaction. The gasifying agent of the fluidized bed 4 is oxygen plus steam, and the reaction temperature is 1300-1500°C. The second gas generated by the reaction is cooled by the second dust collector 43 and then sent to the user through the second gas outlet B, and the slag generated by the reaction is discharged through the discharge device 42.
[0031] A portion of the unreacted coke powder in the circulating fluidized bed 21 is collected by the circulating return unit 2 and re-enters the circulating fluidized bed 21 for reaction, and another portion of small particle fly ash is collected again as a raw material for the fluidized bed 4, thereby realizing the cascade utilization of coke powder, improving the utilization efficiency of coke powder, and greatly reducing the utilization cost of coke powder.
[0032] The above schematically describes the present invention and its implementation methods, which are not restrictive. The drawings show only one implementation method of the present invention, and the actual structure is not limited thereto. Therefore, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.
Claims
1. A coal medium cascade utilization coupled gasification system, comprising a feeding unit (1), a circulating fluidized bed (21) and an entrained bed (4), wherein a feeding inlet of the entrained bed (4) is connected to a coal gas outlet of the circulating fluidized bed (21), characterized in that: The feeding unit (1) comprises a first feeder (14) and a second feeder (15) for feeding a circulating fluidized bed (21), wherein the first feeder (14) is used for conveying raw coal, and the second feeder (15) is used for conveying coke powder or semi-coke powder.
2. The coal medium cascade utilization coupled gasification system according to claim 1 is characterized in that: A cyclone separator (23) is connected between the circulating fluidized bed (21) and the fluidized bed (4); a coal gas outlet of the cyclone separator (23) is in communication with the fluidized bed (4); and a coal slag outlet of the cyclone separator (23) is in communication with the circulating fluidized bed (21).
3. The coal medium cascade utilization coupled gasification system according to claim 2 is characterized in that: A material return device (24) is also connected between the coal slag outlet of the cyclone separator (23) and the circulating fluidized bed (21).
4. The coal medium cascade utilization coupled gasification system according to claim 2 is characterized in that: A fly ash collection unit (3) is connected between the coal gas outlet of the cyclone separator (23) and the fluidized bed (4).
5. The coal medium cascade utilization coupled gasification system according to claim 1 is characterized in that: The fly ash collection unit (3) comprises a first dust collector (31), a fly ash conveying device (32), a dry powder bin (33) and a feeding tank (34) which are connected in sequence; the first dust collector (31) is connected to a cyclone separator (23), and the outlet of the feeding tank (34) is connected to an entrained flow gasifier (41) at the top of the entrained flow bed (4).
6. The coal medium cascade utilization coupled gasification system according to claim 5 is characterized in that: The first dust collector (31) is also provided with a first gas outlet A.
7. The coal medium cascade utilization coupled gasification system according to claim 5 is characterized in that: The fluidized bed (4) is also provided with a second gas outlet B, and a second dust collector (43) is connected between the fluidized bed (4) and the second gas outlet B.
8. The coal medium cascade utilization coupled gasification system according to any one of claims 1 to 7, characterized in that: The first feeder (14) and the second feeder (15) are screw feeders.
9. The coal medium cascade utilization coupled gasification system according to claim 8 is characterized in that: The circulating fluidized bed (21) and the fluidized bed (4) are both provided with gasifying agent inlets.
10. The coal medium cascade utilization coupled gasification system according to claim 8, characterized in that: Slag outlets are provided directly below the circulating fluidized bed (21) and the entrained fluidized bed (4).