Gasification fine ash blending combustion system

Abstract

The invention relates to the technical field of solid waste treatment, and provides a gasified fine ash blending combustion system. A flue gas outlet of a pulverized coal boiler is connected with an inlet of denitration equipment; an outlet of the denitration equipment is divided into a first flue gas branch and a second flue gas branch, the first flue gas branch is connected with a first channel inlet of the heat exchanger, a first channel outlet of the heat exchanger is connected with an inlet of the after-furnace desulfurization equipment, and the second flue gas branch is connected with a flue gas channel inlet of the air pre-heater; a flue gas channel outlet of the air pre-heater is connected with an inlet of the after-furnace desulfurization equipment; an air outlet of the fan is connected with an air channel inlet of the air pre-heater, an air channel outlet of the air pre-heater is connected with a hot air inlet of the coal mill, and a pulverized coal outlet of the coal mill is connected with a burner inlet of the pulverized coal boiler; a second channel of the heat exchanger is a gasified fine ash conveying channel, a second channel outlet of the heat exchanger is connected with an outlet main powder pipe of the coal mill, and the outlet main powder pipe of the coal mill is communicated with a combustor inlet of the pulverized coal boiler.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment technology, specifically to a gasification fine ash co-firing system. Background Technology

[0002] Gasification ash is a solid waste generated during coal gasification, characterized by high carbon content, fine particle size, and poor flowability. Currently, the main methods for treating gasification ash are as raw material for building materials or for decarbonization treatment.

[0003] However, these treatment methods suffer from low resource utilization, high processing costs, and a tendency to cause secondary pollution. They fail to fully realize the energy value of the carbon-containing components and are also difficult to achieve efficient reduction and harmless treatment. Therefore, there is an urgent need for a treatment system that can effectively recover the energy from gasified fine ash, realize its resource utilization, and meet environmental standards. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a gasification fine ash co-firing system to solve the problems of low resource utilization and high pollution risk in gasification fine ash treatment methods, and to achieve the reduction, harmlessness and resource utilization of gasification fine ash.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a gasification fine ash co-firing system, comprising a pulverized coal boiler, denitrification equipment, air preheater, heat exchanger, coal mill, blower, and post-furnace desulfurization equipment;

[0006] The flue gas outlet of the pulverized coal boiler is connected to the inlet of the denitrification equipment;

[0007] The outlet of the denitrification equipment is divided into a first flue gas branch and a second flue gas branch. The first flue gas branch is connected to the inlet of the first channel of the heat exchanger, and the outlet of the first channel of the heat exchanger is connected to the inlet of the desulfurization equipment after the furnace. The second flue gas branch is connected to the inlet of the flue gas channel of the air preheater, and the outlet of the flue gas channel of the air preheater is connected to the inlet of the desulfurization equipment after the furnace.

[0008] The air outlet of the blower is connected to the air passage inlet of the air preheater, the air passage outlet of the air preheater is connected to the hot air inlet of the coal mill, and the pulverized coal outlet of the coal mill is connected to the burner inlet of the pulverized coal boiler.

[0009] The second channel of the heat exchanger is a gasification fine ash conveying channel. The outlet of the second channel of the heat exchanger is connected to the outlet main pulverized coal pipe of the coal mill, and the outlet main pulverized coal pipe of the coal mill is connected to the burner inlet of the pulverized coal boiler.

[0010] Furthermore, the heat exchanger is a tubular heat exchanger, and the first channel and the second channel are isolated from each other and arranged for heat exchange.

[0011] Furthermore, a flue gas regulating valve is provided between the first flue gas branch and the first channel inlet of the heat exchanger.

[0012] Furthermore, the second channel inlet of the heat exchanger is connected to a gasification fine ash conveying pump.

[0013] Furthermore, a mixer is provided on the main pulverized coal outlet pipe of the coal mill, and the second channel outlet of the heat exchanger is connected to the inlet of the mixer.

[0014] The beneficial effects of this invention are:

[0015] 1. The present invention provides a gasification fine ash co-firing system, which couples gasification fine ash with pulverized coal and utilizes the high-temperature combustion environment of the pulverized coal boiler to fully combust the combustible components such as carbon in the gasification fine ash. This achieves both volume reduction of the gasification fine ash and recovery of its energy, thus achieving the goal of resource utilization. At the same time, the combustion process and subsequent pollutant treatment process can effectively avoid secondary pollution caused by the gasification fine ash and achieve harmless treatment.

[0016] 2. The gasification fine ash co-firing system provided by the present invention can remove NOx pollutants that may be generated during the co-firing process through denitrification equipment in the initial stage of flue gas; SO2 pollutants in the flue gas after combustion can be centrally treated through the desulfurization equipment after the furnace, so as to achieve the flue gas emission in compliance with standards and meet environmental protection requirements. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] Attached reference numerals: 1-Pulverized coal boiler, 2-Denitrification equipment, 3-Air preheater, 4-Heat exchanger, 5-Coal mill, 6-Fan, 7-Post-furnace desulfurization equipment, 8-Flue gas regulating valve, 9-Gasification fine ash conveying pump, 10-Mixer. Detailed Implementation

[0019] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0020] In this application, unless otherwise expressly specified and limited, the terms "connection" and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] In the description of this application, it should be understood that the terms "longitudinal", "horizontal", "level", "top", "bottom", "upper", "lower", "inner" and "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and 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, and therefore should not be construed as a limitation of the present invention.

[0022] 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 technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0023] like Figure 1 As shown, the present invention provides a gasification fine ash co-firing system, including a pulverized coal boiler 1, a denitrification device 2, an air preheater 3, a heat exchanger 4, a coal mill 5, a blower 6, and a post-furnace desulfurization device 7, and also includes a flue gas regulating valve 8, a gasification fine ash conveying pump 9, and a mixer 10. The positional relationship and connection relationship of each component are as follows:

[0024] The flue gas outlet of the pulverized coal boiler 1 is fixedly connected to the inlet of the denitrification equipment 2 through a sealed pipeline to ensure that all the flue gas generated by combustion is introduced into the denitrification equipment 2. The outlet of the denitrification equipment 2 is divided into a first flue gas branch and a second flue gas branch. One end of the first flue gas branch is connected to the outlet of the denitrification equipment 2, and the other end is connected to the first channel inlet of the heat exchanger 4 through the flue gas regulating valve 8.

[0025] The first outlet of heat exchanger 4 is connected to the inlet of the desulfurization equipment 7 after the furnace via a pipeline.

[0026] One end of the second flue gas branch is connected to the outlet of the denitrification equipment 2, and the other end is connected to the flue gas inlet of the air preheater 3. The flue gas outlet of the air preheater 3 is connected to the inlet of the desulfurization equipment 7 after the furnace through a pipeline, so that the two flue gas paths merge and enter the desulfurization equipment 7 after the furnace.

[0027] The air outlet of the blower 6 is connected to the air passage inlet of the air preheater 3 through a sealed pipeline. The air passage outlet of the air preheater 3 is connected to the hot air inlet of the coal mill 5. The pulverized coal outlet of the coal mill 5 is connected to the first inlet of the mixer 10. The outlet of the mixer 10 is connected to the burner inlet of the pulverized coal boiler 1 through the main pulverized coal outlet pipe of the coal mill 5.

[0028] The second channel of heat exchanger 4 is a gasification fine ash conveying channel. Its inlet is connected to the outlet of gasification fine ash conveying pump 9. The outlet of the second channel of heat exchanger 4 is connected to the second inlet of mixer 10, so that the gasification fine ash can enter mixer 10 and mix with coal powder after being heated.

[0029] In this embodiment, the first and second channels of heat exchanger 4 are isolated from each other and adopt a tubular heat exchange structure to ensure efficient heat transfer between flue gas and gasified fine ash, while avoiding contact between the two media. Flue gas regulating valve 8 is used to regulate the flow rate of flue gas entering the first channel to adapt to the heating requirements of gasified fine ash under different operating conditions; gasified fine ash conveying pump 9 is used to overcome the problem of poor flowability of gasified fine ash and ensure its stable delivery to heat exchanger 4; mixer 10 is used to fully mix the heated gasified fine ash with pulverized coal to ensure uniform combustion.

[0030] The working principle of this invention is as follows:

[0031] After the pulverized coal boiler 1 is started, the flue gas generated by combustion first enters the denitrification equipment 2 through the pipeline, where the NOx pollutants are removed.

[0032] The flue gas after denitrification is divided into two paths: one path goes through the first flue gas branch and enters the first channel of the heat exchanger 4 through the flue gas regulating valve 8; the other path goes through the second flue gas branch and enters the flue gas channel of the air preheater 3.

[0033] After the blower 6 starts, it delivers ambient temperature air to the air passage of the air preheater 3. The ambient temperature air exchanges heat with the flue gas entering the air preheater 3 from the second flue gas branch and is heated into hot air. The hot air then enters the coal mill 5 through the pipeline, providing drying conditions and conveying power for the grinding of raw coal in the coal mill 5. After the raw coal is ground by the coal mill 5, it forms coal powder, which is then transported to the mixer 10 through the pipeline.

[0034] The gasified fine ash conveying pump 9 is started, conveying the gasified fine ash to the second channel of the heat exchanger 4. The gasified fine ash exchanges heat with the flue gas in the first channel in the second channel and is heated to a suitable combustion temperature. The heated gasified fine ash is then conveyed to the mixer 10 through the pipeline.

[0035] Pulverized coal and heated gasified ash are thoroughly mixed in mixer 10. The mixture is then transported to the burner of pulverized coal boiler 1 through the main pulverized coal outlet pipe of coal mill 5. It is fully combusted in the high-temperature environment of pulverized coal boiler 1, and the combustible components in the gasified ash are completely utilized to release energy.

[0036] After heat exchange, the flue gas in the first channel is discharged from the heat exchanger 4 through the pipeline and merges with the flue gas in the air preheater 3 flue gas channel after heat exchange. They then enter the desulfurization equipment 7 after the furnace, where SO2 pollutants are removed and the treated flue gas is discharged in compliance with standards.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or basic characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0038] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A system for co-combustion of gasified fine ash, characterized by: The coal-fired boiler, the denitration equipment, the air preheater, the heat exchanger, the coal mill, the fan and the post-furnace desulfurization equipment are included. The flue gas outlet of the coal-fired boiler is connected with the inlet of the denitration equipment. The outlet of the denitration equipment is divided into a first flue gas branch and a second flue gas branch, the first flue gas branch is connected with the first channel inlet of the heat exchanger, the first channel outlet of the heat exchanger is connected with the inlet of the post-furnace desulfurization equipment, the second flue gas branch is connected with the flue gas channel inlet of the air preheater, and the flue gas channel outlet of the air preheater is connected with the inlet of the post-furnace desulfurization equipment. The air outlet of the fan is connected with the air channel inlet of the air preheater, the air channel outlet of the air preheater is connected with the hot air inlet of the coal mill, the coal powder outlet of the coal mill is connected with the burner inlet of the coal-fired boiler. The second channel of the heat exchanger is a gasified fine ash conveying channel, the second channel outlet of the heat exchanger is connected with the outlet main powder pipe of the coal mill, and the outlet main powder pipe of the coal mill is communicated with the burner inlet of the coal-fired boiler.

2. The system according to claim 1, characterized in that: The heat exchanger is a tubular heat exchanger, the first channel and the second channel are isolated from each other and arranged in heat exchange.

3. The system according to claim 1, wherein: A flue gas regulating valve is arranged between the first flue gas branch and the first channel inlet of the heat exchanger.

4. The system according to claim 1, wherein: A gasified fine ash conveying pump is connected with the second channel inlet of the heat exchanger.

5. The system according to claim 2, wherein: A mixer is arranged on the outlet main powder pipe of the coal mill, and the second channel outlet of the heat exchanger is connected with the inlet of the mixer.

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