Coal mill drying output device coupled with sludge incineration flue gas waste heat
By coupling the waste heat of sludge incineration flue gas with coal-fired boilers, high-temperature flue gas is used to increase the primary air temperature of the coal mill, the problems of high purification cost of fluidized bed sludge incineration flue gas and blockage of coal mill are solved, and the safe and economical operation of the boiler and the adaptability of high-moisture coal species are achieved.
Patent Information
- Application Number
- CN202420531462.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-19
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-03-19
AI Technical Summary
The flue gas generated by the incineration of fluidized bed sludge needs to be purified separately, which increases investment and operation costs. When the moisture in the coal-fired power plant increases, the primary air temperature and air volume cannot meet the drying requirements, which can easily lead to the clogging of the powder pipe of the coal mill outlet and affect the boiler output.
Couple the waste heat of sludge incineration flue gas with the coal-fired boiler, use high-temperature flue gas to increase the primary air temperature of the coal mill, mix with the primary air through the smoke and air mixing device and enter the coal mill, and set up an air volume and air temperature measurement device for adjustment to avoid blockage of the coal mill outlet and increase the adaptability to high-moisture coal species.
The drying output of coal mill and boiler output are improved, the safe and economical operation of the boiler is ensured, and the investment and operation costs of the flue gas purification system are reduced.
Smart Images
Figure CN223042857U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of power generation, and particularly relates to a coal mill drying output device for coupling the waste heat of sludge incineration flue gas. Background Art
[0002] The harmless treatment of sludge has always been a hot topic in sewage treatment plants and the environmental field. The sludge single incineration technology mainly based on fluidized bed incinerators is the main development direction of sludge treatment at home and abroad. However, the incineration temperature of fluidized bed sludge is relatively low, and the flue gas generated after incineration contains a small amount of toxic gases in addition to certain conventional pollutants. In order to meet the environmental protection emission standards, a separate flue gas purification system needs to be newly built, increasing the investment and operation costs; to save costs, the flue gas can be sent into the high-temperature pulverized coal furnace through the burner nozzle after cooling and dust removal.
[0003] If the moisture content of a coal-fired power plant increases significantly during operation, the existing primary air temperature and air volume will not be able to meet the drying requirements, easily causing blockage in the outlet pulverized coal pipe of the coal mill, thereby reducing the drying output of the coal mill and even affecting the boiler output. Content of the Utility Model
[0004] In order to solve the above problems, the utility model provides a coal mill drying output device for coupling the waste heat of sludge incineration flue gas, which is applicable to the collaborative treatment of sludge incineration plants and coal-fired boilers. The waste heat of the high-temperature flue gas generated by sludge incineration is used to increase the primary air temperature to dry the pulverized coal in the coal mill, improving the adaptability of the coal pulverizing system to high-moisture coal types and ensuring the safe and economic operation of the boiler.
[0005] The embodiments of the utility model are realized through the following technical solutions:
[0006] A coal mill drying output device for coupling the waste heat of sludge incineration flue gas includes a sludge incinerator, a sludge incineration flue gas pipeline with a waste heat boiler, a primary air pipeline, a smoke-air mixing device, and a coal mill. The incineration flue gas of the sludge incinerator is communicated to the sludge incineration flue gas pipeline, and both the sludge incineration flue gas pipeline and the primary air pipeline are communicated to the smoke-air mixing device. The incineration flue gas and the primary air are mixed by the smoke-air mixing device and then sent to the coal mill, and a air volume and air temperature measuring device is provided between the smoke-air mixing device and the coal mill.
[0007] In an embodiment of the utility model, the waste heat boiler includes a first-stage waste heat boiler and a second-stage waste heat boiler connected in series in sequence. The sludge incineration flue gas pipeline includes a low-temperature dust collector and a high-pressure blower connected in series in sequence, and the second-stage waste heat boiler is connected in series with the low-temperature dust collector. The first-stage waste heat boiler is communicated with the sludge incinerator, the air outlet end of the high-pressure blower is communicated with the smoke-air mixing device, and a first flue gas regulating valve is provided between the low-temperature dust collector and the high-pressure blower.
[0008] In an embodiment of the present utility model, the air outlet end of the secondary waste heat boiler is communicated with a high-temperature dust collector. A flue gas shut-off valve is provided between the secondary waste heat boiler and the high-temperature dust collector. The high-temperature dust collector is communicated with a high-pressure fan, and a second flue gas regulating valve is provided between the two.
[0009] In an embodiment of the present utility model, a flue gas circulation pipeline communicating with the sludge incinerator is provided at the outlet end of the low-temperature dust collector. A third flue gas regulating valve and a flue gas circulation fan are connected in series on the flue gas circulation pipeline.
[0010] In an embodiment of the present utility model, the primary air pipeline includes a primary air fan and an air preheater connected in series in sequence. The air preheater is communicated with the flue gas and air mixing device, and a hot air regulating valve is provided between the air preheater and the flue gas and air mixing device.
[0011] In an embodiment of the present utility model, the primary air pipeline further includes a cold primary air pipeline. One end of the cold primary air pipeline is communicated with the air outlet end of the primary air fan, and the other end of the cold primary air pipeline is communicated with the air outlet end of the flue gas and air mixing device. A cold air regulating valve is provided on the cold primary air pipeline.
[0012] The technical solution of the present utility model has at least the following advantages and beneficial effects:
[0013] The present utility model couples a sludge incineration plant and a coal-fired boiler, and uses the waste heat of the high-temperature flue gas generated by sludge incineration to increase the primary air temperature at the inlet of the coal mill in the pulverized coal boiler, so as to dry the pulverized coal in the coal mill, avoid the blockage of the outlet of the coal mill, increase the adaptability of the coal pulverizing system to coal types with high moisture content, improve the drying output of the coal mill and the boiler output, and ensure the safe and economic operation of the boiler. Description of the Drawings
[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.
[0015] Figure 1 It is a schematic diagram of a device for drying the output of a coal mill coupling the waste heat of sludge incineration flue gas in the present utility model.
[0016] Icons: 1 - Incinerator, 2 - Primary waste heat boiler, 3 - Secondary waste heat boiler, 4 - High-temperature dust collector, 5 - Low-temperature dust collector, 6 - Third flue gas regulating valve, 7 - First flue gas regulating valve, 8 - Flue gas shut-off valve, 9 - High-temperature flue gas pipeline, 10 - High-pressure fan, 11 - Flue gas recirculation fan, 12 - Flue gas recirculation pipeline, 13 - Primary air fan, 14 - Air preheater, 15 - Hot air regulating valve, 16 - Hot primary air pipeline, 17 - Cold air regulating valve, 18 - Cold primary air pipeline, 19 - Flue gas and air mixing device, 20 - Air volume and air temperature measuring device, 21 - Coal mill, 22 - Pulverized coal pipeline, 23 - Pulverized coal boiler, 24 - Second flue gas regulating valve. Detailed implementation manners
[0017] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.
[0018] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.
[0019] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0020] In the description of the present utility model, it should be noted that if terms such as "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present utility model is normally placed, it is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present utility model.
[0021] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, if the terms "set", "installed", "configured", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0022] Embodiment
[0023] Please refer to Figure 1 , the present utility model provides a coal mill drying output device for coupling the waste heat of sludge incineration flue gas, which includes a sludge incinerator 1, a sludge incineration flue gas pipeline with a waste heat boiler, a primary air pipeline, a flue gas-air mixing device 19, and a coal mill 21. The incineration flue gas of the sludge incinerator 1 is connected to the sludge incineration flue gas pipeline. The sludge incineration flue gas pipeline and the primary air pipeline of the coal-fired boiler are simultaneously connected to the flue gas-air mixing device 19. The incineration flue gas of the sludge incineration flue gas pipeline and the hot primary air of the primary air pipeline are mixed in the flue gas-air mixing device 19 to form hot primary air at a higher temperature. The mixed hot primary air enters the coal mill 21 to dry the pulverized coal, and carries the pulverized coal through the pulverized coal pipeline 22 to be transported to the pulverized coal boiler 23 for combustion. Moreover, a wind volume and wind temperature measuring device 20 is provided between the flue gas-air mixing device 19 and the coal mill 21, which can measure the wind temperature and wind volume entering the coal mill 21 in real time, so as to control the system to adjust the wind temperature and wind volume entering the coal mill 21.
[0024] Specifically in this embodiment, the waste heat boiler includes a first-stage waste heat boiler 2 and a second-stage waste heat boiler 3 connected in series in sequence. The sludge incineration flue gas pipeline includes a low-temperature dust collector 5 and a high-pressure fan 10 connected in series in sequence. The second-stage waste heat boiler 3 is connected in series with the low-temperature dust collector 5. The first-stage waste heat boiler 2 is connected to the sludge incinerator 1. The outlet end of the high-pressure fan 10 is connected to the flue gas-air mixing device 19. And a first flue gas regulating valve 7 is provided between the low-temperature dust collector 5 and the high-pressure fan 10. The outlet end of the low-temperature dust collector 5 is provided with a flue gas circulation pipeline connected to the sludge incinerator 1. The flue gas circulation pipeline is serially provided with a third flue gas regulating valve 6 and a flue gas circulation fan 11.
[0025] In this embodiment, the primary air pipeline includes a primary air fan 13 and an air preheater 14 connected in series in sequence. The air preheater 14 is communicated with a flue gas-air mixing device 19, and a hot air regulating valve 15 is provided between the air preheater 14 and the flue gas-air mixing device 19 to regulate the amount of hot primary air. The primary air pipeline further includes a cold primary air pipeline 18. One end of the cold primary air pipeline 18 is communicated with the air outlet end of the primary air fan 13, and the other end of the cold primary air pipeline 18 is communicated with the air outlet end of the flue gas-air mixing device 19. A cold air regulating valve 17 is provided on the cold primary air pipeline 18 to regulate the amount of cold primary air. When the pulverized coal boiler 23 is in operation, the primary air is divided into two paths after coming out of the primary air fan 13. One path of air enters the air preheater 14 to absorb heat, and after coming out, it is mixed with the high-temperature incineration flue gas from the high-pressure blower 10 in the flue gas-air mixing device 19. The high-temperature incineration flue gas can further increase the temperature of the hot primary air, thereby increasing the drying capacity of the coal mill 21. The other path of air passes through the cold primary air pipeline 18 and is mixed with the hot air after the flue gas-air mixing device 19. This path of cold air is only opened when necessary to reduce the temperature of the drying medium entering the coal mill 21 and ensure the safe operation of the coal mill 21.
[0026] The high-temperature incineration flue gas generated by the sludge incinerator 1 sequentially enters the first-stage waste heat boiler 2 and the second-stage waste heat boiler 3. In the waste heat boiler, part of the heat of the incineration flue gas is released to heat the steam, and then the incineration flue gas that has been heat-exchanged and cooled and flows out of the second-stage waste heat boiler 3 enters the low-temperature dust collector 5 for dust removal. The flue gas after dust removal by the low-temperature dust collector 5 is divided into two paths. Under normal conditions, the first path of flue gas is opened, that is, the flue gas adjusts the flow rate through the first flue gas regulating valve 7 and is pressurized by the high-pressure blower 10, enters the flue gas-air mixing device 19 to be mixed with the hot primary air, increases the air temperature of the hot primary air, and then enters the coal mill 21; when the moisture content of the coal in the coal mill 21 is relatively low and the demand for high-temperature flue gas of the hot primary air in the primary air pipeline of the pulverized coal boiler 23 decreases, the second path of flue gas can be opened, that is, the third flue gas regulating valve 6 is opened, and the incineration flue gas is sent back to the sludge incinerator 1 for recirculation through the flue gas circulation fan 11 and the flue gas circulation pipeline.
[0027] In this embodiment, the air outlet end of the second-stage waste heat boiler 3 is further communicated with a high-temperature dust collector 4. A flue gas shut-off valve 8 is provided between the second-stage waste heat boiler 3 and the high-temperature dust collector 4. The high-temperature dust collector 4 is communicated with the high-pressure blower 10 and a second flue gas regulating valve 24 is provided between them. When the demand for high-temperature flue gas of the hot primary air in the primary air pipeline of the pulverized coal boiler 23 is relatively large, the flue gas shut-off valve 8 can be opened to extract higher-temperature high-temperature incineration flue gas from the outlet of the first-stage waste heat boiler 2, thereby greatly increasing the air temperature of the hot primary air. It should be noted that the high-temperature flue gas bypass where the high-temperature dust collector 4 is located is only opened when the drying capacity of the coal preparation system is seriously insufficient. For power plants where the output of the coal preparation system is slightly insufficient and the incineration flue gas at the outlet of the second-stage waste heat boiler 3 can meet the drying capacity requirements of the coal preparation system, this bypass can be not provided.
[0028] It should be noted that in this embodiment, a air volume and air temperature measuring device 20 is arranged on the hot primary air duct 16 after mixing to measure the air temperature and air volume introduced into the coal mill 21. In this embodiment, by controlling the opening degrees of the flue gas regulating valve, the flue gas regulating valve, the hot air regulating valve 15, and the cold air regulating valve 17, the air temperature and air volume of the hot primary air after mixing can be effectively adjusted, preventing the boiler efficiency from being reduced due to excessive cold primary air volume while meeting the drying requirements of the coal mill 21.
[0029] It should be noted that when the heat required by the boiler coal pulverizing system decreases, the steam output of the waste heat boiler can be increased to reduce the temperature of the incineration flue gas, so as to avoid excessive cold primary air volume that has not passed through the preheater and reduce the boiler efficiency.
[0030] It should be noted that the flue gas-air mixing device 19 in this embodiment is a prior art, such as a flue gas-air mixer. Those skilled in the art can also adopt other self-made structures. For example, several flow disturbing devices are added in a container provided with inlet and outlet channels, allowing the incineration flue gas and air to enter and mix evenly, and then output.
[0031] In this embodiment, the sludge incineration plant is coupled with the coal-fired boiler, and the waste heat of the high-temperature flue gas generated by sludge incineration is used to increase the primary air temperature at the inlet of the coal mill of the pulverized coal boiler, so as to dry the pulverized coal in the coal mill 21, avoid blockage at the outlet of the coal mill 21, increase the adaptability of the coal pulverizing system to high-moisture coal types, improve the drying capacity of the coal mill and the boiler output, and ensure the safe and economic operation of the boiler.
[0032] In this embodiment, the high-temperature flue gas after sludge incineration is coupled with the hot primary air system of the pulverized coal boiler 23. The high-temperature environment of the pulverized coal boiler 23 and the tail gas purification devices such as desulfurization, denitrification, and dust removal at the tail of the pulverized coal boiler 23 are used to treat the flue gas after sludge incineration, eliminating the need to newly build a sludge incineration flue gas purification device; at the same time, the hot primary air temperature can be increased, thereby improving the drying capacity of the coal mill 21 and increasing the adaptability of the coal pulverizing system to high-moisture coal types.
[0033] 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 coal mill drying output device coupled with waste heat from sludge incineration flue gas, characterized in that: It includes a sludge incinerator, a sludge incineration flue gas pipeline with a waste heat boiler, a primary air pipeline, a smoke-air mixing device and a coal mill. The combustion flue gas of the sludge incinerator is connected to the sludge incineration flue gas pipeline, the sludge incineration flue gas pipeline and the primary air pipeline are both connected to the smoke-air mixing device, the combustion flue gas and the primary air are mixed by the smoke-air mixing device and then passed to the coal mill, and an air volume and air temperature measuring device is provided between the smoke-air mixing device and the coal mill.
2. The coal mill drying output device coupled with waste heat from sludge incineration flue gas according to claim 1 is characterized in that: The waste heat boiler includes a first-level waste heat boiler and a second-level waste heat boiler connected in series in sequence, and the sludge incineration flue gas pipeline includes a low-temperature dust collector and a high-pressure fan connected in series in sequence, and the second-level waste heat boiler is connected in series with the low-temperature dust collector, the first-level waste heat boiler is connected to the sludge incinerator, the air outlet end of the high-pressure fan is connected to the smoke and air mixing device, and a first flue gas regulating valve is provided between the low-temperature dust collector and the high-pressure fan.
3. The coal mill drying output device coupled with waste heat from sludge incineration flue gas according to claim 2 is characterized in that: The air outlet of the secondary waste heat boiler is connected to a high-temperature dust collector, a flue gas shut-off valve is provided between the secondary waste heat boiler and the high-temperature dust collector, the high-temperature dust collector is connected to a high-pressure fan and a second flue gas regulating valve is provided between the two.
4. The coal mill drying output device coupled with waste heat from sludge incineration flue gas according to claim 3 is characterized in that: The outlet end of the low-temperature dust collector is provided with a flue gas circulation pipeline connected to the sludge incinerator, and the flue gas circulation pipeline is provided with a third flue gas regulating valve and a flue gas circulation fan in series.
5. The coal mill drying output device coupled with waste heat from sludge incineration flue gas according to claim 1 is characterized in that: The primary air pipeline includes a primary air fan and an air preheater connected in series in sequence. The air preheater is communicated with the smoke-air mixing device, and a hot air regulating valve is provided between the air preheater and the smoke-air mixing device.
6. A coal mill drying output device coupled with waste heat from sludge incineration flue gas according to claim 5, characterized in that: The primary air pipeline also includes a cold primary air duct, one end of which is connected to the air outlet end of the primary air fan, and the other end of which is connected to the air outlet end of the smoke-air mixing device, and the cold primary air duct is provided with a cold air regulating valve.