Coal-fired unit biomass direct blending combustion conveying device system and method

Abstract

The invention provides a coal-fired unit biomass direct blending combustion conveying device system and method. The coal-fired unit biomass direct blending combustion conveying device system comprises a crushing device, a conveying device, a discharging device and a material sending device which are sequentially connected. A sealing device is arranged outside the conveying device; an outlet of the conveying device is connected with a negative pressure fan through a dust removal air pipe; a material uniformizing device is arranged in the discharging device; the material sending device comprises a low-pressure pneumatic conveying device; and the material sending device is connected with the boiler. Dust generated in the biomass material conveying process is well controlled, and environmental pollution is reduced; and moreover, the problem of blockage of the biomass materials in the conveying process is avoided, and continuous and stable feeding in the biomass blending combustion process can be realized, so that the stability of the combustion process of the boiler is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomass blending combustion, and particularly relates to a biomass direct blending combustion conveying device system and method for a coal-fired unit. BACKGROUND

[0002] Biomass blending combustion includes direct mixing combustion, indirect mixing combustion and parallel combustion. The biomass direct blending combustion technology is to directly send biomass fuel into a furnace by pneumatic conveying, which can bypass the original fuel system of the boiler and is independently arranged, has little modification to the original system, can reuse the existing coal-fired facilities, has a modification cost of only 1 / 5 of a dedicated biomass power plant, can flexibly adjust the blending ratio, is simple to operate, is suitable for existing coal-fired power plants, and can realize biomass blending combustion of the coal-fired unit through simple modification, thereby significantly reducing the carbon emission level of coal power and promoting source reduction of coal power.

[0003] The main problem of pneumatic conveying direct blending combustion of biomass is that biomass is prone to pipe blockage in the pneumatic conveying process. For example, fiber materials such as straw, wood chips and rags are prone to winding and stacking in the conveying process, thereby causing blockage. When the moisture content of biomass is high, the adhesion between particles is significantly enhanced, and clumps are easily formed, thereby causing blockage. Meanwhile, the pneumatic conveying biomass process is prone to dust, because the density of biomass after preliminary crushing is low and the surface is rough, and the micron-sized dust is easily broken under the action of airflow, thereby causing occupational hazards.

[0004] CN220707383U discloses a coal-fired unit coupled blending combustion biomass system using a material passing fan, which comprises a dedusting device, a primary crushing device, a secondary crushing device, a material passing fan, a conveying pipeline and a boiler. The dedusting device, the primary crushing device and the secondary crushing device are arranged in sequence. The inlet of the material passing fan is directly connected to the outlet of the secondary crushing device. The outlet of the material passing fan is connected to the boiler through the conveying pipeline.

[0005] CN218864194U discloses a biomass fuel blending combustion system for a circulating fluidized bed boiler, which comprises a crusher, a jetifier connected to the lower end of the crusher, a fan and a conveying pipeline connected to the left and right ends of the jetifier, an electric valve provided on the conveying pipeline, and a boiler connected to the rear end of the conveying pipeline. The electric valve is connected to a purge air pipe. After waste silk fibers, green leaves and branches, various waste packaging boxes and other biomass materials are put into the crusher, the crushed biomass materials are conveyed into the boiler along the conveying pipeline under the action of the fan and the jetifier, and the purge air pipe blows the conveying pipeline to prevent blockage of the conveying pipeline.

[0006] CN113685806A discloses a biomass blending system based on a coal-fired boiler, which comprises a biomass pretreatment device, a cyclone separator, a bunker and a coal-fired boiler, the biomass pretreatment device crushes biomass and forms biomass particles; the cyclone separator is in communication with the biomass pretreatment device and the bunker respectively, and collects the separated biomass particles into the bunker through the cyclone separator; the bunker is in communication with the coal-fired boiler and conveys the biomass particles in the bunker into the hearth of the coal-fired boiler to realize direct coupling of the biomass and the coal-fired boiler.

[0007] However, the biomass blending system also has the problem of dust generation during the conveying process, which causes environmental pollution. SUMMARY

[0008] In view of the problems in the prior art, the present application provides a biomass direct blending conveying device system and method for a coal-fired unit, which effectively solves the dust problem of the crushed biomass during the conveying process by setting a sealing device and a negative pressure fan for dust removal; by setting a uniform material device and a low-pressure pneumatic conveying device, the biomass is prevented from being blocked during the conveying process of the raw material, realizing continuous and stable conveying of the biomass raw material during the biomass direct blending process of the coal-fired unit, and being suitable for wide range of popularization and application.

[0009] To achieve this purpose, the present application adopts the following technical solutions:

[0010] In a first aspect, the present application provides a biomass direct blending conveying device system and method for a coal-fired unit, which comprises a crushing device, a conveying device, a discharging device and a material sending device connected in sequence;

[0011] The conveying device is externally provided with a sealing device; the outlet of the conveying device is connected with a negative pressure fan through a dust removal air pipe;

[0012] The discharging device is internally provided with a uniform material device;

[0013] The material sending device comprises a low-pressure pneumatic conveying device; the material sending device is connected with a boiler.

[0014] The present application sets a sealing device outside the conveying device to prevent the dust generated from the outlet of the crusher and the outlet of the conveyor from polluting the surrounding working environment; sets a dust removal air pipe and a negative pressure fan at the outlet of the conveying device to discharge the dust generated during the conveying process and introduce it into the plant dust collector for treatment, effectively solving the dust problem during the conveying process of the crushed biomass and reducing environmental pollution; and sets a uniform material device in the discharging device to prevent the material from bridging and blocking at the discharging bin; adopts a low-pressure pneumatic conveying device to keep the biomass material in a suspended state, avoiding blocking at the inlet of the pipeline, and thus realizing continuous and stable conveying of the material to the boiler.

[0015] The working pressure range of the negative pressure fan of the present invention is -3kPa to -1kPa; the working pressure range of the low-pressure pneumatic conveying device is 20kPa to 49kPa.

[0016] Preferably, the conveying device includes a belt conveyor or a scraper conveyor, which can be selected according to the site location and the type of biomass material.

[0017] Preferably, an outlet hopper is provided below the outlet of the conveying device.

[0018] Preferably, the outlet hopper is equipped with a distribution plate, which can evenly feed the crushed biomass material into multiple feeding devices, thus ensuring stable combustion in the boiler.

[0019] Preferably, the number of feeding devices is at least two, for example, two, three, four or five, etc.

[0020] Preferably, the number of material feeding devices is the same as the number of feeding devices, and the material feeding devices are connected to the combustion inlet of the boiler.

[0021] The invention incorporates multiple feeding devices and material delivery devices primarily to ensure stable boiler combustion. For example, a four-corner tangential boiler requires two or four combustion inlets, correspondingly requiring two or four feeding devices and two or four material delivery devices; a front and rear wall opposed boiler requires two combustion inlets, correspondingly requiring two feeding devices and two material delivery devices.

[0022] Preferably, the material leveling device is equipped with a spiral shaft. The rotation of the spiral shaft agitates the material, disrupts the arched structure formed by the material, restores the material to good fluidity, and thus achieves a continuous and stable unloading process, preventing fuel bridging and blockage.

[0023] Preferably, the low-pressure pneumatic conveying device includes a fan, a nozzle, and a diffuser.

[0024] Preferably, the fan is connected to the nozzle.

[0025] Preferably, a mixing chamber is formed between the nozzle and the diffuser. The high-speed airflow generated by the blower continuously ejects the biomass crushed material within the mixing chamber, immediately dispersing it upon entry and preventing clogging.

[0026] Preferably, a gas inlet is provided at the bottom of the mixing chamber, and gas is conveyed from the bottom to the top to keep the crushed biomass material in a suspended state in the mixing chamber, preventing the crushed biomass material from accumulating at the bottom of the mixing chamber and avoiding blockage.

[0027] Secondly, the present invention also provides a method for direct co-firing and conveying of biomass in a coal-fired power unit, wherein the method employs the direct co-firing and conveying device system for biomass in a coal-fired power unit as described in the first aspect; the method includes: after the biomass raw material is crushed by a crushing device, it is conveyed into the boiler via a conveying device, a feeding device and a material sending device to achieve direct co-firing;

[0028] During the transportation of biomass raw materials, the dust emitted from the outlet of the conveying device is discharged through a dust removal duct.

[0029] The method for direct biomass co-firing and conveying in coal-fired power units described in this invention is simple to operate. First, the biomass raw material is crushed in a crushing device, and then sequentially conveyed into the boiler via a conveying device, a feeding device, and a material dispatching device, achieving direct biomass co-firing. This significantly reduces the carbon emission levels of coal-fired power units, promoting emission reduction at the source. During the biomass raw material conveying process, dust emitted from the conveying device outlet is discharged through a dust removal duct and introduced into the plant's dust collector for treatment, effectively preventing dust generation during biomass conveying and reducing environmental pollution.

[0030] Preferably, the biomass includes straw, wood, rice husks, peanut shells, or waste cloth.

[0031] Preferably, the biomass has a moisture content of <20%, for example, it can be 19%, 18%, 15%, 13%, 10%, 8%, or 5%, etc.

[0032] Preferably, the flow rate of biomass raw materials in the material feeding device is 15-25 m / s, for example, it can be 15 m / s, 18 m / s, 20 m / s, 22 m / s, 23 m / s or 25 m / s.

[0033] As a preferred technical solution of the present invention, the method includes: biomass raw materials with a moisture content of <20% are crushed by a crushing device, and then conveyed into a boiler by a conveying device, a feeding device and a material sending device to achieve direct co-firing; the biomass includes straw, wood, rice husks, peanut shells or waste cloth;

[0034] During the biomass raw material transportation process, the dust emitted from the outlet of the conveying device is discharged through the dust removal duct; the flow velocity of the biomass raw material in the material sending device is 15-25 m / s.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] (1) The biomass direct co-firing and conveying device system provided by the present invention effectively controls the dust generated during the biomass material conveying process by setting up a sealing device, dust removal duct and negative pressure fan, reducing environmental pollution, lowering the risk of respiratory diseases for on-site workers and avoiding dust explosion accidents.

[0037] (2) The biomass direct co-firing and conveying device system for coal-fired units provided by the present invention solves the problem of material blockage during biomass conveying by setting up a uniform feeding device and a low-pressure pneumatic conveying device. It can achieve continuous and stable feeding during biomass co-firing, thereby ensuring the stability of the furnace combustion process, promoting the full combustion of biomass, and reducing the loss of unburned carbon. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the biomass direct co-firing and conveying device system of a coal-fired power unit in a specific embodiment of the present invention.

[0039] In the diagram: 1-Crushing device; 2-Conveying device; 3-Sealing device; 4-Dust removal duct; 5-Negative pressure fan; 6-Outlet hopper; 71-First feeding device; 72-Second feeding device; 81-First material leveling device; 82-Second material leveling device; 91-First fan; 92-Second fan; 101-First material sending device; 102-Second material sending device; 11-Boiler. Detailed Implementation

[0040] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0042] It should be understood that in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0043] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] Those skilled in the art should understand that the present invention necessarily includes the necessary pipelines, conventional valves and general pump equipment for achieving process integrity, but the above content is not the main inventive point of the present invention. Those skilled in the art can add layouts based on process flow and equipment structure selection, and the present invention does not make any special requirements or specific limitations in this regard.

[0045] As a specific embodiment of the present invention, a biomass direct co-firing and conveying device system for coal-fired power units is provided, the structural schematic diagram of which is shown below. Figure 1 As shown.

[0046] The biomass direct co-firing and conveying device system of the coal-fired unit includes a crushing device 1, a conveying device 2, a feeding device and a material sending device connected in sequence;

[0047] The conveying device 2 is equipped with a sealing device 3 on its exterior; the outlet of the conveying device 2 is connected to the negative pressure fan 5 via a dust removal duct 4.

[0048] In this specific embodiment, there are two feeding devices, namely the first feeding device 71 and the second feeding device 72.

[0049] The feeding device is equipped with a material leveling device; the number of material leveling devices is the same as the number of feeding devices, namely a first material leveling device 81 and a second material leveling device 82.

[0050] The number of material sending devices is the same as the number of unloading devices, namely the first material sending device 101 and the second material sending device 102.

[0051] The material conveying device is a low-pressure pneumatic conveying device; the material conveying device is connected to the boiler 11.

[0052] The conveyor device 2 is a belt conveyor.

[0053] An outlet hopper 6 is provided below the outlet of the conveying device 2; a material distribution plate is provided inside the outlet hopper 6.

[0054] The material leveling device is equipped with a spiral shaft.

[0055] The low-pressure pneumatic conveying device includes a blower, a nozzle, and a diffuser; the blower is connected to the nozzle; a mixing chamber is formed between the nozzle and the diffuser.

[0056] In this specific embodiment, a first fan 91 and a second fan 92 are included.

[0057] A gas inlet is provided at the bottom of the mixing chamber.

[0058] As a specific embodiment of the present invention, a method for direct co-firing and conveying of biomass from a coal-fired power unit is also provided, the method comprising:

[0059] Biomass raw material with a moisture content of 10% is crushed by crushing device 1, and then conveyed into boiler via conveying device 2, feeding device and material sending device to achieve direct co-firing; the biomass is peanut shells;

[0060] During the biomass raw material transportation process, the dust emitted from the outlet of the conveying device 2 is discharged through the dust removal duct 4; the flow velocity of the biomass raw material in the material sending device is 20m / s.

[0061] In summary, the biomass direct co-firing and conveying device system for coal-fired power units provided by this invention effectively controls the dust generated during the biomass material conveying process by setting up sealing devices, dust removal ducts, and negative pressure fans. This reduces environmental pollution, lowers the risk of respiratory diseases for on-site workers, and avoids dust explosion accidents. By setting up a material equalization device and a low-pressure pneumatic conveying device, the problem of material blockage during biomass conveying is solved, enabling continuous and stable feeding during biomass co-firing. This ensures stable combustion in the boiler furnace, promotes complete biomass combustion, reduces unburned carbon loss, and has broad application prospects.

[0062] The applicant declares that the detailed structural features of the present invention are illustrated through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components selected in the present invention, additions of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0063] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A biomass direct co-firing and conveying device system for coal-fired power units, characterized in that, The biomass direct co-firing and conveying device system of the coal-fired unit includes a crushing device, a conveying device, a feeding device and a material sending device connected in sequence; The conveying device is equipped with a sealing device on its exterior; the outlet of the conveying device is connected to a negative pressure fan via a dust removal duct. The feeding device is equipped with a material leveling device; The material conveying device includes a low-pressure pneumatic conveying device; the material conveying device is connected to the boiler.

2. The biomass direct co-firing and conveying device system for coal-fired power units according to claim 1, characterized in that, The conveying device includes a belt conveyor or a scraper conveyor.

3. The biomass direct co-firing and conveying device system for coal-fired power units according to claim 1 or 2, characterized in that, An outlet hopper is provided below the outlet of the conveying device; Preferably, the outlet hopper is equipped with a material distribution plate.

4. The biomass direct co-firing and conveying device system for coal-fired power units according to any one of claims 1 to 3, characterized in that, The number of the feeding devices is at least two; Preferably, the number of material feeding devices is the same as the number of unloading devices.

5. The biomass direct co-firing and conveying device system for coal-fired power units according to any one of claims 1 to 4, characterized in that, The material leveling device is equipped with a spiral shaft.

6. The biomass direct co-firing and conveying device system for coal-fired power units according to any one of claims 1 to 5, characterized in that, The low-pressure pneumatic conveying device includes a blower, nozzles, and a diffuser; Preferably, the fan is connected to the nozzle; Preferably, a mixing chamber is formed between the nozzle and the diffuser.

7. The biomass direct co-firing and conveying device system for coal-fired power units according to claim 6, characterized in that, A gas inlet is provided at the bottom of the mixing chamber.

8. A method for direct co-firing and conveying of biomass from a coal-fired power unit, characterized in that, The method is carried out using the direct biomass co-firing and conveying device system of any one of claims 1 to 7; the method includes: after the biomass raw material is crushed by the crushing device, it is conveyed into the boiler by the conveying device, the feeding device and the material sending device to realize direct co-firing; During the transportation of biomass raw materials, the dust emitted from the outlet of the conveying device is discharged through a dust removal duct.

9. The method according to claim 8, characterized in that, The biomass includes straw, wood, rice husks, peanut shells, or waste cloth; Preferably, the moisture content of the biomass is <20%.

10. The method according to claim 8 or 9, characterized in that, The flow rate of biomass raw materials in the material delivery device is 15-25 m / s.

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