Zhundong coal fluidized bed-entrained-flow bed two-section type grading gasification system
The two-stage staged gasification system of fluidized bed and entrained flow bed solved the problem of coking in Zhundong coal, realized a highly efficient and stable coal gasification process, and improved carbon conversion rate and system energy efficiency.
Patent Information
- Application Number
- CN202520167721.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2025-12-30
- Estimated Expiration
- 2035-01-24
AI Technical Summary
Existing technologies are insufficient to effectively address the problem of coking in Zhundong coal, leading to unstable operation of gasification units. Furthermore, the differences in conversion characteristics among different coal types result in low efficiency of a single gasification method.
A two-stage staged gasification system, consisting of a fluidized bed and an entrained flow bed, is adopted. By combining the fluidized bed and the entrained flow bed, different types of coal with different properties are gasified in stages. The fluidized bed handles the easily gasifiable portion, while the entrained flow bed handles the difficult-to-gasify portion. The carbon conversion rate and system energy efficiency are improved through high-temperature feeding and sensible heat recovery.
It has achieved efficient gasification of Zhundong coal, improved carbon conversion rate, reduced coking risk, ensured long-term stable operation of gasification unit, and improved system energy efficiency.
Smart Images
Figure CN223738002U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of coal chemical technology, and more specifically to a two-stage staged gasification system for Zhundong coal (high alkali coal) using fluidized bed-gaseous flow bed. Background Technology
[0002] Coal gasification is a core technology for the clean and efficient conversion and utilization of coal, and it forms the basis for processes such as the production of industrial fuel gas, natural gas, IGCC power generation, synthetic ammonia, methanol, coal-based chemicals, and coal-based polygeneration. Currently, coal gasification can be divided into three types of gasification processes: fixed-bed, fluidized-bed, and entrained-flow gasification. Fixed-bed gasification has low investment costs, but its single-furnace processing capacity is small, and the crude gas contains tar and phenolic water, resulting in significant pollution. It is unsuitable for large-scale gasification and has been gradually phased out. Fluidized-bed gasification has strong adaptability to different coal types, low oxygen consumption and coal preparation costs, and low investment costs, making it suitable for fuel gas production. However, it suffers from severe "upward and downward flow" problems, leading to low carbon conversion rates and difficulties in utilizing high-carbon gasification ash. Entrained gasification systems offer high gasification temperatures (1400℃~1600℃), large throughput, high carbon conversion rates, and liquid slag discharge. However, the high-temperature gas-water quenching wet slag discharge results in high energy and water consumption, short service life of gasifier nozzles and refractory linings, and increased operating costs. Furthermore, entrained gasification systems have strict requirements for raw coal, making them unsuitable for low-rank coals with poor grindability. Conventional coal gasification technologies typically employ a single gasification process to process coal. To achieve high carbon conversion rates and reaction rates under single gasification conditions, they employ a high-temperature, high-pressure, pure oxygen-based, and vigorous reaction method. While this improves reaction efficiency and carbon conversion rates, the entire process results in high energy consumption and the complete gasification and decomposition of high-calorific-value small-molecule hydrocarbons, leading to a decrease in the calorific value of the coal gas. The complex structure of coal, with different components exhibiting different conversion characteristics, makes it unsuitable for a single, crude conversion method.
[0003] Therefore, how to provide a two-stage staged gasification system for Zhundong coal fluidized bed-flow bed to solve the problem of coking in gasification devices using Zhundong coal as raw material and ensure the long-term stable operation of the gasification device is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content
[0004] In view of this, this utility model provides a two-stage staged gasification system for Zhundong coal, consisting of a fluidized bed and an entrained flow bed, to solve the problem of coking in gasification devices using Zhundong coal as raw material, and to ensure long-term stable operation of the gasification device.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A two-stage staged gasification system for Zhundong coal, consisting of a fluidized bed and an entrained flow bed, includes:
[0007] A fluidized bed gasifier, wherein the fluidized bed gasifier is provided with a fluidized bed coal feed port and a slag discharge pipe is provided at the bottom of the fluidized bed gasifier;
[0008] A primary cyclone separator is connected to the fluidized bed gasifier. The coarse semi-coke particles separated by the primary cyclone separator are returned to the fluidized bed gasifier via a return feeder. The primary cyclone separator is also connected to a secondary cyclone separator.
[0009] A fly ash storage tank, which is connected to the secondary cyclone separator, is provided with a nitrogen inlet and a nitrogen outlet;
[0010] The gasifier is equipped with a high-temperature gas quencher at the top, a high-temperature nozzle on the gasifier, and a nitrogen outlet on the fly ash storage tank. The gasifier is also equipped with a pressure relief port.
[0011] The processing component is equipped with a gasification fan. The processing component is connected to the fluidized bed gasifier through a high-temperature air preheater. The secondary cyclone separator is also connected to the processing component. The processing component is sequentially connected to a bag filter, a gas cooler, and a quench fan. The quench fan is connected to the high-temperature gas quencher.
[0012] Furthermore, the processing components include a superheater, an evaporator, an economizer, and a low-temperature air preheater. The secondary cyclone separator is sequentially connected to the superheater, evaporator, economizer, and low-temperature air preheater. The low-temperature air preheater is connected to the fluidized bed gasifier through the high-temperature air preheater. The gasification fan is installed on the low-temperature air preheater. The low-temperature air preheater is sequentially connected to the bag filter, gas cooler, and quench fan.
[0013] Furthermore, it also includes a slag crusher, which is installed at the bottom of the fluidized bed gasifier and is connected to a slag remover via a slag discharge lock hopper.
[0014] Furthermore, the bottom of the fluidized bed gasifier is provided with an air distribution plate in the form of an air cap and a gasifying agent mixing chamber.
[0015] Furthermore, the return feeder is equipped with a return fan.
[0016] Furthermore, the upper part of the fluidized bed gasifier is provided with a fine coal powder inlet and a special coal powder nozzle, and the high-temperature gas quencher at the top outlet of the fluidized bed gasifier is set as a multi-tube jet rapid mixing structure.
[0017] Furthermore, the fluidized bed gasifier is configured with a cylindrical structure, and the gas flow bed gasifier is configured with a gas-solid countercurrent flow type.
[0018] Furthermore, the high-temperature nozzle of the airflow bed is a multi-pass composite cooling high-temperature nozzle.
[0019] As can be seen from the above technical solution, compared with the prior art, this utility model discloses a two-stage staged gasification system for Zhundong coal fluidized bed-gaseous bed, the beneficial effects of which are:
[0020] 1. By organically combining fluidized bed gasifiers and entrained flow gasifiers, staged gasification of coal is achieved. The easily gasifiable portion (about 80%) is gasified in the fluidized bed, while the difficult-to-gasify portion (about 20% fly ash) is gasified in the entrained flow bed, thus improving the gasification efficiency and carbon conversion rate.
[0021] 2. Appropriately reduce the operating temperature of the fluidized bed gasifier to solve the problem of coking when Zhundong coal is used as raw coal;
[0022] 3. Fine coal powder is injected into the upper part of the fluidized bed gasifier to recover the sensible heat of the high-temperature coal gas and increase the calorific value of the coal gas.
[0023] 4. A quencher and an air preheater are installed at the top of the fluidized bed to maximize the recovery of the sensible heat of the high-temperature coal gas and improve the system energy efficiency;
[0024] 5. The fluidized bed adopts a high-temperature feeding method to solve the problem of the gasification temperature of fly ash in the fluidized bed. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0026] Figure 1 This is a schematic diagram of the structure of the two-stage staged gasification system for Zhundong coal fluidized bed-gaseous bed provided by this utility model.
[0027] The components are as follows: 1 is a fluidized bed gasifier; 2 is a fluidized bed coal feed inlet; 3 is a slag discharge pipe; 4 is a primary cyclone separator; 5 is a return feeder; 6 is a secondary cyclone separator; 7 is a fly ash storage tank; 8 is a nitrogen inlet; 9 is a nitrogen outlet; 10 is a fluidized bed gasifier; 11 is a high-temperature gas quencher; 12 is a fluidized bed high-temperature nozzle; 13 is a pressure relief port; 14 is a gasification blower; 15 is a high-temperature air preheater; 16 is a bag filter; 17 is a gas cooler; 18 is a quench blower; 19 is a superheater; 20 is an evaporator; 21 is an economizer; 22 is a low-temperature air preheater; 23 is a slag crusher; 24 is a slag discharge lock hopper; 25 is a slag remover; 26 is a return feeder; and 27 is a fine coal powder inlet and a special coal powder nozzle. Detailed Implementation
[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0029] See Figure 1 This utility model discloses a two-stage staged gasification system for Zhundong coal, consisting of a fluidized bed and an entrained flow bed, comprising:
[0030] Fluidized bed gasifier 1, with a fluidized bed coal feed port 2 on the fluidized bed gasifier 1 and a slag discharge pipe 3 at the bottom of the fluidized bed gasifier 1;
[0031] The first-stage cyclone separator 4 is connected to the fluidized bed gasifier 1. The coarse semi-coke particles separated by the first-stage cyclone separator 4 are returned to the fluidized bed gasifier 1 through the return feeder 5. The first-stage cyclone separator 4 is connected to the second-stage cyclone separator 6.
[0032] Fly ash storage tank 7 is connected to the secondary cyclone separator 6. Fly ash storage tank 7 is equipped with nitrogen inlet 8 and nitrogen outlet 9.
[0033] The fluidized bed gasifier 10 has a high-temperature gas quencher 11 at its top and high-temperature nozzles 12 connected to the nitrogen outlet 9 on the fly ash storage tank 7. A pressure relief port 13 is also provided. By incorporating the high-temperature gas quencher 11 and the high-temperature air preheater 15, the sensible heat of the high-temperature gas is recovered to the maximum extent, improving system energy efficiency. The organic combination of the fluidized bed gasifier 1 and the fluidized bed gasifier 10 enables staged gasification of coal; the easily gasifiable portion is gasified in the fluidized bed, while the less easily gasifiable portion is gasified in the fluidized bed gasifier 10. This reduces the system's feed requirements while improving gasification efficiency and carbon conversion rate.
[0034] The processing component is equipped with a gasification blower 14. The processing component is connected to the fluidized bed gasifier 1 through a high-temperature air preheater 15. The secondary cyclone separator 6 is also connected to the processing component. The processing component is connected in sequence to a bag filter 16, a gas cooler 17 and a quench blower 18. The quench blower 18 is connected to a high-temperature gas quencher 11.
[0035] In this embodiment, the processing components include a superheater 19, an evaporator 20, an economizer 21, and a low-temperature air preheater 22. A secondary cyclone separator 6 is connected in sequence to the superheater 19, the evaporator 20, the economizer 21, and the low-temperature air preheater 22. The low-temperature air preheater 22 is connected to the fluidized bed gasifier 1 through a high-temperature air preheater 15. A gasification fan 14 is installed on the low-temperature air preheater 22. The low-temperature air preheater 22 is connected in sequence to a bag filter 16, a gas cooler 17, and a quench fan 18.
[0036] In this embodiment, a slag crusher 23 is also included. The slag crusher 23 is located at the bottom of the fluidized bed gasifier 10 and is connected to the slag remover 25 through the slag discharge lock hopper 24.
[0037] In this embodiment, the bottom of the fluidized bed gasifier 1 is provided with an air distribution plate in the form of an air cap and a gasifying agent mixing chamber.
[0038] In this embodiment, the return material device 5 is equipped with a return material fan 26.
[0039] In this embodiment, the upper part of the fluidized bed gasifier 10 is provided with a fine coal powder inlet and a special coal powder nozzle 27, and the high temperature gas cooler 11 at the top outlet of the fluidized bed gasifier 10 is set as a multi-tube jet rapid mixing structure; the fine coal powder inlet and the special coal powder nozzle 27 at the upper part of the fluidized bed gasifier 10 are used to inject fine coal powder into the fluidized bed gasifier 10.
[0040] In this embodiment, the fluidized bed gasifier 1 is configured as a cylindrical structure, and the gas flow bed gasifier 10 is configured as a gas-solid countercurrent type.
[0041] In this embodiment, the high-temperature nozzle 12 of the airflow bed is a multi-pass composite cooling high-temperature nozzle.
[0042] Specific usage process
[0043] Pulverized coal of 0-10mm is fed into the fluidized bed gasifier 1 through the fluidized bed feed port 2 via a screw feeder and enters the bottom of the fluidized bed gasifier 1. Under high temperature conditions of 800℃-900℃, it undergoes a gasification reaction with air and steam gasifying agent to generate combustible gases such as H2, CO, and CH4. The gas carries solid semi-coke particles upward into the high-temperature primary cyclone separator 4 for separation. The coarse semi-coke separated by the primary cyclone separator 4 is returned to the bottom of the fluidized bed gasifier 1 for recycling reaction via the return feeder 5. The slag is discharged from the slag discharge pipe 3 at the bottom of the fluidized bed gasifier 1.
[0044] The fly ash separated by the secondary cyclone separator 6 enters the fly ash storage tank 7, and then the high-temperature fly ash (around 500℃) is sent to the fluidized bed gasifier 10 via pneumatic conveying (using N2 as the conveying medium). Under high-temperature conditions of 1300℃~1500℃, it undergoes a high-temperature slag gasification reaction with air and steam gasifying agent. The liquid slag is discharged through the slag crusher 23 and then enters the slag removal machine 25 through the slag lock hopper 24 for discharge. The high-temperature coal gas generated by gasification rises and violently mixes with the fine coal powder injected into the upper part of the fluidized bed gasifier 10 to generate pyrolysis gas. Simultaneously, the sensible heat of the high-temperature coal gas is recovered to lower the temperature. The gas from the top outlet of the fluidized bed gasifier 10 sequentially enters the high-temperature gas quencher 11 and the high-temperature air preheater 15 to further recover the sensible heat of the high-temperature gas. Finally, it flows into the main gas pipeline at the outlet of the fluidized bed gasifier 1, and then enters the waste heat boiler to recover heat and produce by-product steam for external transmission. The cooled gas enters the bag filter 16 for further dust removal and purification, and finally enters the gas cooler 17 to be cooled to 45°C. A portion of the cooled gas (about 25%) is circulated by the quench fan 18 into the high-temperature gas quencher 11 at the top outlet of the fluidized bed gasifier 10 to cool the high-temperature gas. The remaining gas is sent to the next process.
[0045] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0046] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A quasi-dong coal fluidized bed-entrained flow bed two-stage staged gasification system, characterized in that, The application relates to a fluidized bed gasification furnace, a primary cyclone separator, a fly ash storage tank, a gas flow bed gasification furnace, a treatment assembly and a slag breaker. The fluidized bed gasification furnace is provided with a fluidized bed coal feeding port, and the bottom of the fluidized bed gasification furnace is provided with a slag discharge pipe. The primary cyclone separator is communicated with the fluidized bed gasification furnace, and the primary cyclone separator is communicated with a secondary cyclone separator. The fly ash storage tank is communicated with the secondary cyclone separator, and the fly ash storage tank is provided with a nitrogen inlet and a nitrogen outlet. The gas flow bed gasification furnace is provided with a high-temperature coal gas quencher at the top, and is provided with a gas flow bed high-temperature nozzle, which is communicated with the nitrogen outlet of the fly ash storage tank. The treatment assembly is communicated with the fluidized bed gasification furnace through a high-temperature air preheater, and is also communicated with the secondary cyclone separator.
2. The quasi-dong coal fluidized bed - gas flow bed two-stage staged gasification system of claim 1, wherein, The treatment assembly is sequentially communicated with a bag-type dust collector, a coal gas cooler and a quenching fan, and the quenching fan is communicated with the high-temperature coal gas quencher.
3. The quasi-dong coal fluidized bed - gas flow bed two-stage staged gasification system according to claim 1, characterized in that, The treatment assembly comprises a superheater, an evaporator, a coal-saving device and a low-temperature air preheater, the secondary cyclone separator is sequentially connected with the superheater, the evaporator, the coal-saving device and the low-temperature air preheater, the low-temperature air preheater is communicated with the fluidized bed gasification furnace through the high-temperature air preheater, the gasification fan is arranged on the low-temperature air preheater, and the low-temperature air preheater is sequentially communicated with the bag-type dust collector, the coal gas cooler and the quenching fan.
4. The quasi-dong coal fluidized bed - gas flow bed two-stage staged gasification system according to claim 1, characterized in that, The slag breaker is arranged at the bottom of the gas flow bed gasification furnace and is communicated with a slag extractor through a slag discharge lock hopper.
5. The quasi-dong coal fluidized bed - gas flow bed two-stage staged gasification system according to claim 1, characterized in that, The fluidized bed gasification furnace is provided with a wind cap type air distribution plate and a gasification agent mixing chamber at the bottom.
6. The quasi-dong coal fluidized bed - gas flow bed two-stage staged gasification system according to claim 1, characterized in that, The return air fan is arranged on the return feeder.
7. The quasi-dong coal fluidized bed - gas flow bed two-stage staged gasification system according to claim 1, characterized in that, The gas flow bed gasification furnace is provided with a fine coal powder inlet and a special coal powder nozzle at the upper portion, and the high-temperature coal gas quencher at the top outlet of the gas flow bed gasification furnace is provided with a multi-pipe jet flow rapid mixing structure.
8. The quasi-dong coal fluidized bed - gas flow bed two-stage staged gasification system of claim 1, characterized in that, The fluidized bed gasification furnace is provided with a straight cylinder structure, and the gas flow bed gasification furnace is provided with a gas-solid countercurrent type. The gas flow bed high-temperature nozzle is a multi-pass composite cooling high-temperature nozzle.