Clean and efficient gasification fine slag carbon residue combustion system

Abstract

The invention discloses a clean and efficient gasification fine slag and carbon residue combustion system, and relates to the technical field of boilers. The problem that in the combustion treatment process of gasified fine slag, a traditional carbon residue combustion system is poor in stable combustion capacity, and therefore the heat load of the section is low is solved. High-temperature flue gas generated by a circulating fluidized bed boiler is extracted to drying equipment, high-moisture gasified fine slag is fully dried, moisture can be dried to 10%, then gasified fine slag raw materials are fully crushed through crushing equipment, the problem that part of gasified fine slag carbon residues of an entrained-flow bed cannot be burnt out due to the fact that the gasified fine slag carbon residues are wrapped by a molten mass shell is solved, and the utilization rate of the entrained-flow bed is increased. The stable combustion capability of the gasified fine slag is improved; and the gasified fine slag is mixed into the pulverized coal for combustion, and the pulverized coal is quickly ignited, so that the gasified fine slag can be fully preheated, and the burnout level of the gasified fine slag is improved. The device and the method are suitable for combustion treatment of gasified fine slag carbon residues.

Description

Technical Field

[0001] The invention relates to the technical field of boilers, and in particular to a clean and efficient gasification fine slag and carbon residue combustion system. Background Art

[0002] Gasification fine slag is a by-product of the coal gasification process. It contains a lot of unburned carbon and has a high value for resource utilization. Data from the "China Bulk Industrial Solid Waste Comprehensive Utilization Industry Development Report" show that my country's gasification slag production in 2021 was about 71 million tons, and the comprehensive utilization rate was only 31.6%. Compared with pulverized coal, gasification fine slag has a high water content, small particle size, and significantly higher activation energy, which makes ignition and burnout difficult; low volatile matter and large ash content, the use of conventional combustion methods has problems such as weak stable combustion ability and low cross-sectional heat load. Up to now, there has been no universal combustion and utilization plan for gasification fine slag produced under different gasification processes, gasification temperatures, and gasification coals.

[0003] In summary, the traditional residual carbon combustion system has a weak combustion stabilization ability during the combustion treatment of gasified fine slag, which leads to the problem of low cross-sectional heat load. Summary of the invention

[0004] The present invention proposes a clean and efficient gasification fine slag carbon residue combustion system to solve the problem that the traditional carbon residue combustion system has weak combustion stabilization ability during the combustion treatment of gasification fine slag, resulting in low cross-sectional heat load.

[0005] A clean and efficient gasification fine slag and residual carbon combustion system of the present invention comprises a drying device 1, a crushing device 2, a pulverized coal bin 3, a feeding system 4, a circulating fluidized bed boiler 5, a cyclone separator 6, a high-temperature heat exchanger 7, a fan 8, a dust removal device 9 and a chimney 10;

[0006] The output end of the circulating fluidized bed boiler 5 is connected to the input end of the cyclone separator 6, the output end of the cyclone separator 6 is connected to the top input end of the high-temperature heat exchanger 7, the bottom output end of the high-temperature heat exchanger 7 is connected to the input end of the dust removal device 9, the output end of the dust removal device 9 is connected to the chimney 10, the upper output end of the side of the high-temperature heat exchanger 7 is connected to the input end of the fan 8, the output end of the fan 8 is connected to the input end of the drying device 1, the output end of the drying device 1 is connected to the input end of the crushing device 2, the output end of the crushing device 2 is connected to the top input end of the feeding system 4, the output end of the feeding system 4 is connected to the input end of the circulating fluidized bed boiler 5, and the discharge port of the pulverized coal bin 3 is connected to the side input end of the feeding system 4;

[0007] Furthermore, the side of the circulating fluidized bed boiler 5 is provided with an output end and an input end in sequence from top to bottom;

[0008] Furthermore, the output end of the upper side of the circulating fluidized bed boiler 5 is connected to the input end of the upper side of the cyclone separator 6 through a pipeline;

[0009] Furthermore, the input end at the lower side of the circulating fluidized bed boiler 5 is connected to the bottom output end of the cyclone separator 6 through a pipeline;

[0010] Furthermore, a control valve is provided at the connection between the bottom output end of the high-temperature heat exchanger 7 and the input end of the dust removal device 9;

[0011] Furthermore, a gasification fine slag input port is provided on the side of the drying device 1;

[0012] Furthermore, when in use, the gasified fine slag with high moisture content is transported to the drying equipment 1, and is fully dried under the action of the high-temperature flue gas extracted from the boiler side. After drying, the gasified fine slag that is partially wrapped by the molten shell is crushed by the crushing equipment 2, so that the residual carbon of the gasified fine slag is exposed to oxygen to promote combustion. The dried and crushed gasified fine slag raw material is mixed with coal powder, and the mixed fuel enters the circulating fluidized bed boiler 5 for combustion according to the designed ratio through the feeding system 4. The post-combustion products are separated in the cyclone separator 6, and the gasified fine slag that is not fully burned returns to the circulating fluidized bed boiler 5 to continue burning. Part of the high-temperature flue gas is extracted by the fan 8 before the high-temperature heat exchanger 7 to the drying equipment 1 for drying the high-moisture gasified fine slag, thereby reducing the overall energy consumption. The tail flue gas is treated by the dust removal device 9 and discharged from the chimney 10. The low-carbon ash slag produced is collected and landfilled or mixed with road building materials to achieve harmless treatment.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention overcomes the disadvantages of the prior art. The high-temperature flue gas generated by the circulating fluidized bed boiler is extracted to a drying device to fully dry the high-moisture gasified fine slag, and the moisture can be dried to 10%. The gasified fine slag raw material is then fully crushed by a crushing device, thereby solving the problem that the residual carbon of some fluidized bed gasified fine slag cannot be completely burned due to being wrapped by the outer shell of the molten body, and improving the stable combustion ability of the gasified fine slag. The gasified fine slag is then mixed with coal powder for combustion. Since the coal powder ignites quickly, the gasified fine slag can be fully preheated, thereby improving the burnout level of the gasified fine slag.

[0015] Use a high-efficiency circulating fluidized bed boiler for blending. The circulating fluidized bed boiler has the advantages of wide fuel adaptability, high combustion efficiency and low pollutant emissions. Design a slender furnace to increase the residence time of the mixed fuel in the furnace, making the combustion more complete, helping to solve the problem of the difficulty in burning gasified fine slag and increase the cross-sectional heat load of the gasified fine slag. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is a structural schematic diagram of a clean and efficient gasification fine slag and carbon residue combustion system according to the present invention. DETAILED DESCRIPTION

[0017] Specific implementation method 1: Combination Figure 1 The present embodiment is described as a clean and efficient gasification fine slag and residual carbon combustion system, which comprises a drying device 1, a crushing device 2, a pulverized coal bin 3, a feeding system 4, a circulating fluidized bed boiler 5, a cyclone separator 6, a high-temperature heat exchanger 7, a fan 8, a dust removal device 9 and a chimney 10;

[0018] The output end of the circulating fluidized bed boiler 5 is connected to the input end of the cyclone separator 6, the output end of the cyclone separator 6 is connected to the top input end of the high-temperature heat exchanger 7, the bottom output end of the high-temperature heat exchanger 7 is connected to the input end of the dust removal device 9, the output end of the dust removal device 9 is connected to the chimney 10, the upper output end of the side of the high-temperature heat exchanger 7 is connected to the input end of the fan 8, the output end of the fan 8 is connected to the input end of the drying device 1, the output end of the drying device 1 is connected to the input end of the crushing device 2, the output end of the crushing device 2 is connected to the top input end of the feeding system 4, the output end of the feeding system 4 is connected to the input end of the circulating fluidized bed boiler 5, and the discharge port of the pulverized coal bin 3 is connected to the side input end of the feeding system 4;

[0019] In this specific embodiment, when in use, high-moisture gasified fine slag is transported to the drying equipment 1, and is fully dried under the action of the high-temperature flue gas extracted from the boiler side. After drying, the gasified fine slag that is partially wrapped by the molten shell is crushed by the crushing equipment 2, so that the residual carbon of the gasified fine slag is exposed to oxygen to promote combustion. The dried and crushed gasified fine slag raw material is mixed with coal powder, and the mixed fuel enters the circulating fluidized bed boiler 5 for combustion according to the designed ratio through the feeding system 4. The post-combustion products are separated in the cyclone separator 6, and the incompletely burned gasified fine slag returns to the circulating fluidized bed boiler 5 to continue burning. Part of the high-temperature flue gas is extracted by the fan 8 before the high-temperature heat exchanger 7 to the drying equipment 1 for drying the high-moisture gasified fine slag, thereby reducing the overall energy consumption. The tail flue gas is treated by the dust removal device 9 and discharged from the chimney 10. The low-carbon ash slag produced is collected and landfilled or mixed with road building materials to achieve harmless treatment.

[0020] Specific implementation method 2: Combination Figure 1 This embodiment is described as a further limitation of the combustion system described in the first embodiment. This embodiment describes a clean and efficient gasification fine slag and carbon residue combustion system, and the side of the circulating fluidized bed boiler 5 is provided with an output end and an input end in sequence from top to bottom.

[0021] Specific implementation method three: Combination Figure 1To explain this embodiment, this embodiment is a further limitation of the combustion system described in the second specific embodiment. This embodiment describes a clean and efficient gasification fine slag and carbon residue combustion system, in which the output end of the upper side of the circulating fluidized bed boiler 5 is connected to the input end of the upper side of the cyclone separator 6 through a pipeline.

[0022] Specific implementation method four: Combination Figure 1 To explain this embodiment, this embodiment is a further limitation of the combustion system described in the specific embodiment three. This embodiment describes a clean and efficient gasification fine slag and carbon residue combustion system, in which the input end at the lower side of the circulating fluidized bed boiler 5 is connected to the bottom output end of the cyclone separator 6 through a pipeline.

[0023] Specific implementation method five: Combination Figure 1 To explain this embodiment, this embodiment is a further limitation of the combustion system described in the specific embodiment 1. This embodiment describes a clean and efficient gasification fine slag and carbon residue combustion system, in which a control valve is provided at the connection between the bottom output end of the high-temperature heat exchanger 7 and the input end of the dust removal device 9.

[0024] Specific implementation method six: Combination Figure 1 This embodiment is described as a further limitation of the combustion system described in the first embodiment. This embodiment describes a clean and efficient gasification fine slag and carbon residue combustion system, and a gasification fine slag input port is provided on the side of the drying equipment 1.

[0025] How it works

[0026] When in use, the gasified fine slag with high moisture content is transported to the drying equipment 1, and is fully dried under the action of the high-temperature flue gas extracted from the boiler side. After drying, the gasified fine slag partially wrapped by the molten shell is crushed by the crushing equipment 2, so that the residual carbon of the gasified fine slag is exposed to oxygen to promote combustion. The dried and crushed gasified fine slag raw material is mixed with coal powder, and the mixed fuel enters the circulating fluidized bed boiler 5 for combustion according to the designed ratio through the feeding system 4. The post-combustion products are separated in the cyclone separator 6, and the gasified fine slag that is not fully burned returns to the circulating fluidized bed boiler 5 to continue burning. Part of the high-temperature flue gas is extracted by the fan 8 before the high-temperature heat exchanger 7 to the drying equipment 1 for drying the high-moisture gasified fine slag, thereby reducing the overall energy consumption. The tail flue gas is treated by the dust removal device 9 and discharged from the chimney 10. The low-carbon ash slag generated is collected and landfilled or mixed with road building materials to achieve harmless treatment.

Claims

1. A clean and efficient gasification fine slag and carbon residue combustion system, characterized by: It includes a drying device (1), a crushing device (2), a pulverized coal bin (3), a feeding system (4), a circulating fluidized bed boiler (5), a cyclone separator (6), a high-temperature heat exchanger (7), a fan (8), a dust removal device (9) and a chimney (10); The output end of the circulating fluidized bed boiler (5) is connected to the input end of the cyclone separator (6), the output end of the cyclone separator (6) is connected to the top input end of the high-temperature heat exchanger (7), the bottom output end of the high-temperature heat exchanger (7) is connected to the input end of the dust removal device (9), the output end of the dust removal device (9) is connected to the chimney (10), the upper output end of the side of the high-temperature heat exchanger (7) is connected to the input end of the fan (8), the output end of the fan (8) is connected to the input end of the drying device (1), the output end of the drying device (1) is connected to the input end of the crushing device (2), the output end of the crushing device (2) is connected to the top input end of the feeding system (4), the output end of the feeding system (4) is connected to the input end of the circulating fluidized bed boiler (5), and the discharge port of the pulverized coal bin (3) is connected to the side input end of the feeding system (4).

2. A clean and efficient gasification fine slag and carbon residue combustion system according to claim 1, characterized in that: The side of the circulating fluidized bed boiler (5) is provided with an output end and an input end in sequence from top to bottom.

3. A clean and efficient gasification fine slag and carbon residue combustion system according to claim 2, characterized in that: The output end at the upper side of the circulating fluidized bed boiler (5) is connected to the input end at the upper side of the cyclone separator (6) through a pipeline.

4. A clean and efficient gasification fine slag and carbon residue combustion system according to claim 3, characterized in that: The input end at the lower side of the circulating fluidized bed boiler (5) is connected to the bottom output end of the cyclone separator (6) through a pipeline.

5. A clean and efficient gasification fine slag and carbon residue combustion system according to claim 1, characterized in that: A control valve is provided at the connection between the bottom output end of the high-temperature heat exchanger (7) and the input end of the dust removal device (9).

6. A clean and efficient gasification fine slag and carbon residue combustion system according to claim 1, characterized in that: A gasified fine slag input port is provided on the side of the drying device (1).

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