Device and method for burnout of gasification ash slurry in a front and rear wall opposed firing boiler

Abstract

An apparatus and method for burning out gasified ash slurry in a front and rear wall opposed firing boiler belong to the technical field of gasified ash treatment. The apparatus for burning out gasified ash slurry in a front and rear wall opposed firing boiler of the present invention includes a furnace, a slurry / coal powder dual-purpose swirl burner, a material homogenizer, a coal slurry pump, and a coal powder burner. The front wall and the rear wall of the furnace are both equipped with slurry / coal powder dual-purpose swirl burners and coal powder burners. The number of slurry / coal powder dual-purpose swirl burners and coal powder burners is multiple and arranged in rows. The slurry / coal powder dual-purpose swirl burner is connected to the material homogenizer through a coal slurry pump. The research and development purpose of the present invention is to solve the problems that the direct combustion effect of gasified ash and slag is poor, and at present, a dehydration device is required for treating gasified ash, which will be accompanied by the discharge of solid waste and pollute the environment. By directly injecting the gasified ash slurry into the front and rear wall boiler for combustion and simultaneously adjusting the burners injecting the gasified ash slurry, the consumption of gasified ash can be achieved.

Description

Technical Field

[0001] The present invention relates to a device and method for burning out gasification ash slurry in a front and rear wall opposed firing boiler, belonging to the technical field of gasification ash treatment. Background Art

[0002] The output of gasification ash and slag is affected by factors such as coal type, gasification process, and production scale. The ash and slag content and properties produced by different types of gasification processes are different. For example, there are certain differences in the ash and slag produced by fixed bed gasification and fluidized bed gasification.

[0003] Gasification ash and slag usually have the characteristics of fine particles, with a particle size generally between dozens of micrometers and a few millimeters, and have a high water content. This gasification ash and slag has good dispersibility and suspension in water, and is suitable for forming a stable water coal slurry form. The water coal slurry not only has good stability, but also has great advantages in the transportation process and storage process.

[0004] As a common coal-fired boiler, the front and rear wall boiler has a relatively simple structure, usually consisting of basic components such as a boiler body, combustion equipment, and flue gas exhaust system. The furnace temperature of this type of boiler is high, and the burnout rate of fuel is high, which can effectively improve energy utilization efficiency.

[0005] The prior art invention patent "Gasification Ash and Slag Incineration System and Combustion Method" with the patent number CN202311075189.6 and the patent publication date of August 24, 2023, and the application publication number CN117053207A processes and utilizes gasification ash and slag by grinding and separating the exhausted gas from the gasification ash and slag and sending it into a combustion furnace for incineration. During the incineration process, the burner ignites the pulverized coal, and the generated heat and waste gas are introduced into the furnace body through the air box to achieve effective treatment of the gasification ash and slag. Although this method can achieve the treatment and utilization of gasification ash and slag, only treating the gasification ash and slag by drying and grinding is not conducive to industrial treatment of gasification ash, requires additional dehydration equipment, and has low utilization rate.

[0006] The prior art invention patent "Gasification Ash and Slag Treatment Device, Method and Coal Catalytic Gasification System" with the patent number CN20201—06359—26.3 and the patent publication date of July 3, 2020, and the application publication number CN111826207A uses a specific device to treat gasification ash and slag in a shell. The gasification ash and slag, additive, and plasma oxygen are input into the shell through the first feed port, second feed port, and inlet pipe, and then a residual carbon oxidation reaction and a catalyst replacement reaction occur in the shell to achieve the conversion of residual carbon in the gasification ash and slag and the extraction of the catalyst. Although this method can effectively convert the residual carbon in the gasification ash and slag and improve the carbon conversion rate, the device used in this invention is numerous and the operation steps are complex, which is not suitable for large-scale promotion in industrial production.

[0007] The invention patent of the prior art, "A Treatment Method for Coal Chemical Gasification Residue", with the patent number CN201210511610.9 and the patent publication date of March 20, 2013, and the application publication number CN102980195A, uniformly mixes coal slime and gasification residue after adding water, then adds white mud slurry, and transports it through a high-pressure piston pump pipeline to a fluidized bed boiler for combustion treatment. The temperature of the fluidized bed is low, and for gasification ash with a high degree of graphitization, the burnout effect is poor.

[0008] Therefore, it is urgent to propose a device and method for burning out gasification ash slurry in a front and rear wall opposed firing boiler to solve the above technical problems. Summary of the Invention

[0009] The research and development purpose of the present invention is to solve the problems that the direct combustion effect of gasification ash and slag is poor, and a dehydration device is required for treating gasification ash at present, which will be accompanied by the discharge of solid waste and pollute the environment. By directly injecting the gasification ash slurry into a front and rear wall boiler for combustion, and simultaneously adjusting the burner for injecting the gasification ash slurry, the consumption of gasification ash can be achieved. A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0010] Technical solution of the present invention:

[0011] Solution 1: A device for burning out gasification ash slurry in a front and rear wall opposed firing boiler, including a furnace, a slurry / coal powder dual-purpose swirl burner, a material homogenizer, a coal slurry pump, and a coal powder burner. The front wall and the rear wall of the furnace are both equipped with slurry / coal powder dual-purpose swirl burners and coal powder burners. The number of slurry / coal powder dual-purpose swirl burners and coal powder burners is multiple and arranged in rows. The slurry / coal powder dual-purpose swirl burner is connected to the material homogenizer through a coal slurry pump.

[0012] Preferably: The row-arranged slurry / coal powder dual-purpose swirl burners are arranged in the middle layer of the coal powder burners.

[0013] Preferably: The row-arranged slurry / coal powder dual-purpose swirl burners are arranged in the upper layer of the coal powder burners.

[0014] Preferably: The slurry / coal powder dual-purpose swirl burner is provided with a secondary air pipe and a fuel pipe. The fuel pipe is connected to the coal powder bin through a coal powder valve, and the fuel pipe is connected to the coal slurry pump through a slurry valve.

[0015] Preferably, the slurry / coal powder dual-purpose cyclone burner controls the injection of slurry into the fuel pipe through a slurry valve, and the slurry / coal powder dual-purpose cyclone burner controls the injection of coal powder into the fuel pipe through a coal powder valve.

[0016] Solution 2: A method for burning out the gasification ash slurry in a front and rear wall opposed firing boiler is realized by relying on the device for burning out the gasification ash slurry in a front and rear wall opposed firing boiler described in Solution 1, and includes the following steps:

[0017] Step 1, feeding the gasification ash and slag into a homogenizing machine to prepare a gasification ash slurry;

[0018] Step 2, using a coal slurry pump to control the flow rate of the gasification ash slurry and feeding it into the slurry / coal powder dual-purpose cyclone burner;

[0019] Step 3, opening the slurry valve of the slurry / coal powder dual-purpose cyclone burner and closing the coal powder valve, and injecting the gasification ash slurry into the upper and middle layers of the furnace;

[0020] Step 4, arranging the coal powder burner on the other side wall of the furnace facing the slurry / coal powder dual-purpose cyclone burner. At the same time, the coal powder burner injects coal powder into the furnace, and the slurry / coal powder dual-purpose cyclone burner injects the gasification ash slurry into the furnace to form opposed firing, ensuring that the central temperature of the furnace is maintained above 1400 °C;

[0021] Step 5, when the storage capacity of the gasification ash slurry in the homogenizing machine is insufficient, opening the coal powder valve and the slurry valve of the slurry / coal powder dual-purpose cyclone burner, mixing and incorporating the gasification ash slurry and coal powder, and injecting them into the upper and middle layers of the furnace for combustion;

[0022] Step 6, when the storage capacity of the gasification ash slurry in the homogenizing machine is zero, opening the coal powder valve of the slurry / coal powder dual-purpose cyclone burner to normally switch the furnace to coal combustion operation, and the coal powder realizes front and rear wall opposed firing.

[0023] Preferably, the method for preparing the gasification ash slurry includes:

[0024] Step 1.1, after crushing and rolling the gasification ash and slag, feeding it into a homogenizing machine, and the particle size range of the gasification ash and slag is 10 μm to 100 μm;

[0025] Step 1.2, adding water into the homogenizing machine to make the water content of the gasification ash slurry within the range of 30% to 60%.

[0026] The present invention has the following beneficial effects:

[0027] 1. The present invention directly uses the gasification ash slurry as fuel and burns it in a front and rear wall opposed firing boiler, without the need for an additional dehydration device to dry the gasification ash;

[0028] 2. The present invention can improve work efficiency. When burning and gasifying ash, there is no need to use a fluidized bed boiler to burn and gasify ash slag. Without affecting the normal operation of the power station boiler, according to the consumption situation of gasified ash, the slurry / pulverized coal dual-purpose swirl burners put into operation can be adjusted, thereby realizing the combustion of gasified ash slurry, that is, without affecting the normal working efficiency of the boiler and solving the problem of the treatment of gasified ash slag.

[0029] 3. The present invention can improve the combustion efficiency of gasified ash slurry. There is no need to add white mud slurry to ensure that gasified ash slag can be burned and treated in a fluidized bed. The front and rear wall opposed firing boiler is used to burn gasified ash slurry, and the combustion temperature at the center of the furnace is above 1400°C. The high combustion temperature is conducive to complete combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of a device for complete combustion of gasified ash slurry using a front and rear wall opposed firing boiler;

[0031] Figure 2 is a schematic structural diagram of a slurry / pulverized coal dual-purpose swirl burner;

[0032] Figure 3 is a schematic layout diagram of the pulverized coal valve and slurry valve of the present invention;

[0033] Figure 4 is a schematic layout diagram of the slurry / pulverized coal dual-purpose swirl burner of the present invention;

[0034] In the figure, 1 - furnace, 2 - slurry / pulverized coal dual-purpose swirl burner, 3 - material distributor, 4 - coal slurry pump, 5 - pulverized coal burner, 21 - secondary air duct, 22 - fuel pipe, 23 - pulverized coal valve, 24 - slurry valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be described below through specific embodiments shown in the drawings. However, it should be understood that these descriptions are exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0036] The connections mentioned in the present invention are divided into fixed connections and detachable connections. The fixed connection is an inseparable connection, including but not limited to conventional fixed connection methods such as flanging connection, riveting connection, bonding connection and welding connection, etc. The detachable connection includes but not limited to conventional disassembly methods such as threaded connection, snap connection, pin connection and hinge connection, etc. When the specific connection method is not clearly defined, it is defaulted that at least one connection method can always be found among the existing connection methods to achieve this function, and those skilled in the art can select according to their needs. For example: welding connection is selected for fixed connection, and hinge connection is selected for detachable connection.

[0037] Specific Embodiment 1: Combined with Figures 1 - 4 To describe this embodiment, a device for burning out the gasification ash slurry in a front and rear wall opposed firing boiler includes a furnace 1, a slurry / coal powder dual-purpose swirl burner 2, a material homogenizer 3, a coal slurry pump 4, and a coal powder burner 5. The slurry / coal powder dual-purpose swirl burners 2 and the coal powder burners 5 are installed on both the front wall and the rear wall of the furnace 1. The number of the slurry / coal powder dual-purpose swirl burners 2 and the coal powder burners 5 is multiple and they are arranged in rows. The slurry / coal powder dual-purpose swirl burner 2 is connected to the material homogenizer 3 through the coal slurry pump 4. After the gasification ash slag is put into the material homogenizer 3, it is made into gasification ash slurry by adding water and stirring, and then is sent into the slurry / coal powder dual-purpose swirl burner 2 through the coal slurry pump 4, so that the two jets of the gasification ash slurry and the coal powder can collide with each other in the center of the furnace and form a high-temperature area through mutual disturbance.

[0038] The arranged slurry / coal powder dual-purpose swirl burners 2 are arranged in the middle layer of the coal powder burners 5, as Figure 1 shown.

[0039] A more preferred technical solution is that the arranged slurry / coal powder dual-purpose swirl burners 2 are arranged in the upper layer of the coal powder burners 5, as Figure 4 shown.

[0040] The slurry / coal powder dual-purpose swirl burner 2 is provided with a secondary air duct 21 and a fuel pipe 22. The fuel pipe 22 is connected to the coal powder bin through a coal powder valve 23, and the fuel pipe 22 is connected to the coal slurry pump 4 through a slurry valve 24.

[0041] The slurry / coal powder dual-purpose swirl burner 2 controls the injection of slurry into the fuel pipe 22 through the slurry valve 24, and the slurry / coal powder dual-purpose swirl burner 2 controls the injection of coal powder into the fuel pipe 22 through the coal powder valve 23, and can burn the gasification ash slurry alone or burn the coal powder alone.

[0042] Specific Embodiment 2: Combined with Figures 1 - 4 To describe this embodiment, a method for burning out the gasification ash slurry in a front and rear wall opposed firing boiler is realized based on the device for burning out the gasification ash slurry in a front and rear wall opposed firing boiler described in Specific Embodiment 1, and is characterized by including the following steps:

[0043] Step 1, sending the gasification ash slag into the material homogenizer 3 to prepare gasification ash slurry;

[0044] Step 2, using the coal slurry pump 4 to control the flow rate of the gasification ash slurry and sending it into the slurry / coal powder dual-purpose swirl burner 2;

[0045] Step 3: Open the slurry valve 24 of the dual-purpose slurry / coal powder swirl burner 2, close the coal powder valve 23, and inject the gasified ash slurry into the upper-middle layer of the furnace 1.

[0046] Step 4: Arrange the coal powder burner 5 on the other side wall of the furnace 1 facing the dual-purpose slurry / coal powder swirl burner 2. At the same time, inject coal powder into the furnace 1 through the coal powder burner 5, and inject the gasified ash slurry into the furnace 1 through the dual-purpose slurry / coal powder swirl burner 2 to form counter-flow combustion, ensuring that the central temperature of the furnace 1 is maintained above 1400 °C.

[0047] Step 5: When the gasified ash slurry storage in the batcher 3 is insufficient, open the coal powder valve 23 and the slurry valve 24 of the dual-purpose slurry / coal powder swirl burner 2, mix and blend the gasified ash slurry and coal powder, with the blending ratio ranging from 0% to 100%, and then inject it into the upper-middle layer of the furnace 1 for combustion.

[0048] Step 6: When the gasified ash slurry storage in the batcher 3 is zero, open the coal powder valve 23 of the dual-purpose slurry / coal powder swirl burner 2 to normally switch the furnace 1 to coal combustion operation, and the coal powder realizes front-back wall counter-flow combustion.

[0049] The method for preparing the gasified ash slurry includes:

[0050] Step 1.1: After crushing and rolling the gasified ash slag, feed it into the batcher 3, and the particle size range of the gasified ash slag is 10 μm to 100 μm.

[0051] Step 1.2: Add water into the batcher 3 to make the water content of the gasified ash slurry within the range of 30% to 60%.

[0052] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutation and combination. Therefore, the present invention will not explain the technical solutions after permutation and combination one by one, but it should be understood that the technical solutions after permutation and combination have been disclosed by the present invention.

[0053] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for burnout of gasification ash slurry in a front and rear wall opposed firing boiler is realized by relying on the device for burnout of gasification ash slurry in a front and rear wall opposed firing boiler, and is characterized in that: The device for burning out the gasification ash slurry in a front and rear wall opposed firing boiler includes a furnace (1), a slurry / coal powder dual-purpose swirl burner (2), a material homogenizer (3), a coal slurry pump (4), and a coal powder burner (5). The front wall and the rear wall of the furnace (1) are both equipped with the slurry / coal powder dual-purpose swirl burner (2) and the coal powder burner (5). The number of the slurry / coal powder dual-purpose swirl burners (2) and the coal powder burners (5) is multiple and they are arranged in rows. The slurry / coal powder dual-purpose swirl burner (2) is connected to the material homogenizer (3) through the coal slurry pump (4); The row-arranged slurry / coal powder dual-purpose swirl burners (2) are arranged in the middle layer of the coal powder burners (5); The row-arranged slurry / coal powder dual-purpose swirl burners (2) are arranged in the upper layer of the coal powder burners (5); The slurry / coal powder dual-purpose swirl burner (2) is provided with a secondary air duct (21) and a fuel pipe (22). The fuel pipe (22) is connected to the coal powder bin through a coal powder valve (23), and the fuel pipe (22) is connected to the coal slurry pump (4) through a slurry valve (24); The slurry / coal powder dual-purpose swirl burner (2) controls the injection of slurry into the fuel pipe (22) through the slurry valve (24), and the slurry / coal powder dual-purpose swirl burner (2) controls the injection of coal powder into the fuel pipe (22) through the coal powder valve (23); After the gasification ash slag is put into the material homogenizer (3), it is made into gasification ash slurry by adding water and stirring, and then is sent into the slurry / coal powder dual-purpose swirl burner (2) through the coal slurry pump (4), so that two jets of gasification ash slurry and coal powder collide with each other in the center of the furnace, and are mutually disturbed to form a high-temperature area; It also includes the following steps: Step 1: Send the gasification ash slag into the material homogenizer (3) to prepare gasification ash slurry; Step 2: Use the coal slurry pump (4) to control the flow rate of the gasification ash slurry and send it into the slurry / coal powder dual-purpose swirl burner (2); Step 3: Open the slurry valve (24) of the slurry / coal powder dual-purpose swirl burner (2) and close the coal powder valve (23), and inject the gasification ash slurry into the middle and upper layers of the furnace (1); Step 4: Arrange the coal powder burner (5) on the other side wall of the furnace (1) facing the slurry / coal powder dual-purpose swirl burner (2). At the same time, the coal powder burner (5) injects coal powder into the furnace (1), and the slurry / coal powder dual-purpose swirl burner (2) injects gasification ash slurry into the furnace (1) to form opposed firing, ensuring that the central temperature of the furnace (1) is maintained above 1400 °C; Step 5: When the storage of the gasification ash slurry in the material homogenizer (3) is insufficient, open the coal powder valve (23) and the slurry valve (24) of the slurry / coal powder dual-purpose swirl burner (2), mix and incorporate the gasification ash slurry and coal powder, and inject them into the middle and upper layers of the furnace (1) for combustion; Step 6: When the storage of the gasification ash slurry in the material homogenizer (3) is zero, open the coal powder valve (23) of the slurry / coal powder dual-purpose swirl burner (2) to normally switch the furnace (1) to coal combustion operation, and the coal powder realizes front and rear wall opposed firing.

2. A method for burnout of gasification ash slurry in a front and rear wall opposed firing boiler according to claim 1, characterized in that: The method for preparing the gasification ash slurry includes: Step 1.1: After crushing and rolling the gasified ash residue, introduce it into the material homogenizer (3). The particle size range of the gasified ash residue is 10 μm to 100 μm. Step 1.2: Add water into the material homogenizer (3) to make the water content of the gasified ash slurry within the range of 30% to 60%.

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