Fly ash supplementing type coal and biomass coupling combustion device and system
By using a fly ash-supplemented coal-biomass co-combustion device, the problem of biomass fuel slagging in boilers has been solved, resulting in extended boiler heating surface lifespan, reduced equipment maintenance costs, and improved biomass co-firing ratio and carbon emission reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CPI NORTHEAST ENERGY SAVING TECH
- Filing Date
- 2022-11-17
- Publication Date
- 2026-07-14
AI Technical Summary
Biomass fuel contains alkali metals during combustion, which leads to boiler slagging, reduces the lifespan of heating surfaces, and increases equipment maintenance costs. Furthermore, the ash generated from coal combustion does not precisely influence the migration process of alkali metals, limiting the proportion of biomass blending.
A fly ash-supplemented coal-biomass coupled combustion device is adopted, in which fly ash directly participates in the biomass combustion process, precisely acting on alkali metal migration. The fly ash-supplemented coal-biomass coupled combustion system, including the design of a central air duct, a coal-biomass coupled air-powder channel, and a primary air-fly ash supplementary air channel, realizes the mixing and combustion of fly ash and biomass fuel.
It effectively reduces slagging on boiler heating surfaces, increases the proportion of biomass co-firing, reduces equipment maintenance costs, enhances the carbon emission reduction efforts of power plants, and extends the service life of boiler heating surfaces.
Smart Images
Figure CN115854338B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of boiler technology, and in particular to a fly ash-supplemented coal and biomass coupled combustion device and system. Background Technology
[0002] Among various biomass power generation technologies, direct combustion of solid fuels has advantages such as simple production processes, relatively mature technology, and low initial investment, and therefore has received significant attention. However, biomass fuels contain a certain amount of alkali metals, which can cause slagging in boilers during combustion, reducing the lifespan of heating surfaces and increasing equipment maintenance costs.
[0003] In the power generation sector, biomass replaces coal, achieving emission reduction at the source. However, the effect of ash from coal combustion on alkali metal migration is not precise, limiting the biomass blending ratio, and boiler heating surfaces still experience significant slagging. Summary of the Invention
[0004] To address the aforementioned problems, this invention proposes a fly ash-supplemented coal-biomass coupled combustion device. This device utilizes fly ash to directly participate in the biomass combustion process, precisely targeting the alkali metal migration process and further reducing slagging on the heating surfaces of the coal-coupled biomass power generation boiler. This invention also proposes a fly ash-supplemented coal-biomass coupled combustion system.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0006] In the first technical solution, a fly ash-supplemented coal-biomass coupled combustion device includes a central air duct, a coal-biomass coupled air-powder channel, and a supplementary primary air-powdered fly ash airflow channel. The coal-biomass coupled air-powder channel is fitted outside the central air duct, and the output ends of the central air duct and the coal-biomass coupled air-powder channel are in the same direction and coaxially arranged. The supplementary primary air-powdered fly ash airflow channel is fitted outside the coal-biomass coupled air-powder channel, and the output ends of the supplementary primary air-powdered fly ash airflow channel and the coal-biomass coupled air-powder channel are in the same direction and coaxially arranged.
[0007] The tail end of the main body of the supplementary primary air fly ash airflow channel is open. Near the front end of the supplementary primary air fly ash airflow channel, there is an outer input ring sleeve. The input ring sleeve is sealed to the outer wall of the main body of the supplementary primary air fly ash airflow channel. At the front end of the main body of the supplementary primary air fly ash airflow channel, corresponding to the inner cavity of the input ring sleeve, there is a supplementary primary air fly ash airflow regulating baffle.
[0008] In the first technical solution, as a preferred embodiment, the inner diameter of the rear section of the coal-biomass coupling air-powder channel assembly in the central air duct section is larger than the inner diameter of the front section, and the middle part of the coal-biomass coupling air-powder channel assembly in the central air duct section is a bucket-shaped narrowing section, which has an air-powder airflow guide plate for spiral output of the air-powder airflow.
[0009] In the first technical solution, as a preferred embodiment, the fly ash supplementary coal and biomass coupled combustion device further includes a secondary air duct. The inner diameter of the rear section of the coal and biomass coupled air-powder channel is larger than that of the front section. The main body of the secondary air duct is fitted in the middle of the coal and biomass coupled air-powder channel and is a bucket-shaped narrowing section. This narrowing section has a secondary air guide plate.
[0010] In the first technical solution, as a preferred embodiment, the front end of the secondary air duct body is flared, and the supplementary primary fly ash airflow regulating baffle is set at the flared end of the secondary air duct.
[0011] In the first technical solution, preferably, the output port of the coal and biomass coupled air-powder channel is located in front of the output port of the central air duct, and the output end of the coal and biomass coupled air-powder channel is located behind the starting position of the front end flared section of the main body of the supplementary primary air-powder fly ash airflow channel.
[0012] In the first technical solution, a fly ash-supplemented coal-biomass coupled combustion system is provided, using a fly ash-supplemented coal-biomass coupled combustion device as described in any one of the first technical solutions. The fly ash-supplemented coal-biomass coupled combustion system further includes a pulverized coal conveying component, a biomass pulverized coal conveying component, and a fly ash pulverized coal conveying component. The fly ash-supplemented coal-biomass coupled combustion device is installed in the boiler combustion chamber. The output ends of the pulverized coal conveying component and the biomass pulverized coal conveying component are connected to the input end of the coal-biomass coupled air-powder channel of the fly ash-supplemented coal-biomass coupled combustion device after mixing. The output end of the fly ash pulverized coal conveying component is connected to the inside of the input ring of the supplementary primary air-fly ash airflow channel.
[0013] In the second technical solution, as a preferred embodiment, the pulverized coal conveying assembly includes a raw coal bunker, a coal feeder, and a coal mill, wherein the output end of the raw coal bunker is connected to the coal mill via the coal feeder, and the output end of the coal mill is connected to a fly ash-supplemented coal-biomass coupled combustion device.
[0014] In the second technical solution, as a preferred embodiment, the biomass powder conveying assembly includes a biomass storage silo, a primary distributor, a secondary distributor, a crusher, a grinding mill, and a feeder. The output end of the biomass storage silo is connected to the input end of the primary distributor, the output end of the primary distributor is connected to the crusher, the output end of the crusher is connected to the grinding mill through the secondary distributor, and the output end of the grinding mill is connected to a fly ash-supplemented coal-biomass coupled combustion device through the feeder.
[0015] In the second technical solution, preferably, a dust collector ash hopper is provided at the flue gas emission end of the boiler. The ash powder conveying assembly includes a hopper pump, an ash quantity regulating device, and a compressed air station. The output end of the dust collector ash hopper is connected to the input end of the hopper pump. The ash quantity regulating device is located at the output end of the hopper pump. The output end of the compressed air station is connected to the output end of the hopper pump. Part of the hopper pump outlet is transported to the ash field by compressed air, and the other part is carried to the fly ash supplemental coal and biomass coupled combustion device by supplemental primary hot air.
[0016] In the second technical solution, as a preferred embodiment, the boiler has an external flue gas circulation duct, and the output end of the coal ash powder conveying component also has a preheating flue. Parts of the pipes of the preheating flue and the external flue gas circulation duct are connected to a supplementary primary air preheater. The supplementary primary air preheater preheats the output material in the preheating flue through the external flue gas circulation duct.
[0017] The beneficial effects of using this invention are:
[0018] 1. In the fly ash supplemented coal and biomass coupled combustion device of the present invention, the primary air fly ash airflow channel coincides with the axis of the central air duct. The scaling structure allows the fly ash airflow to better wrap the coal and biomass coupled air-powder airflow, so as to achieve the best combustion-supporting effect. The primary air fly ash airflow is arranged with a guide plate, so that the scaling structure allows the fly ash airflow to be fully mixed with the air-powder airflow during the combustion process.
[0019] 2. The fly ash-supplemented coal-biomass co-combustion system of the present invention uses fly ash, a waste material from power plants, as a supplement, which is low in cost and has a good effect on reducing slagging on the heating surface. The present invention further increases the proportion of biomass co-combustion and strengthens the source carbon emission reduction of coal-fired biomass power plants.
[0020] 3. This device and system are widely applicable to various fuel types. When the type of coal or biomass fuel changes, the amount of fly ash can be adjusted to further suppress slagging on the boiler heating surface during biomass combustion, extend the service life of the heating surface of the biomass co-fired power plant boiler, and reduce equipment maintenance costs. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the fly ash-supplemented coal and biomass coupled combustion device of the present invention.
[0022] Figure 2 This is a schematic diagram of the fly ash-supplemented coal and biomass coupled combustion system of the present invention.
[0023] Figure 3 Graph showing experimental data on alkali metal content in ash from the coupled combustion of rice husks and coal under conditions without fly ash supplementation.
[0024] Figure 4 The experimental data of alkali metal content in rice husk and coal coupled combustion ash under fly ash supplementation conditions after using the fly ash supplementation coal and biomass coupled combustion device of the present invention is shown in the figure.
[0025] Figure 5 Data chart of ash composition from the coupled combustion of rice husks and coal under fly ash supplementation conditions.
[0026] Figure 6 Enlarged view of the ash morphology of rice husks and coal coupled combustion under conditions without fly ash replenishment.
[0027] Figure 7 Enlarged view of the ash morphology of rice husk and coal coupled combustion under fly ash replenishment conditions after using the fly ash replenishment coal and biomass coupled combustion device of the present invention.
[0028] The reference numerals in the figures include:
[0029] 1-Raw coal bunker, 2-Coal feeder, 3-Coal mill, 4-Biomass storage bunker, 51-Primary feeder, 52-Secondary feeder, 6-Crusher, 7-Grinding mill, 8-Pulverizer, 9-Fly ash supplementary coal and biomass coupled combustion device, 10-Boiler, 11-Supplementary primary air preheater flue gas inlet damper, 12-Supplementary primary air preheater, 13-Supplementary primary air preheater outlet flue gas check damper, 14-Supplementary primary air outlet damper, 15-Supplementary primary air inlet damper, 16-Dust collector ash hopper, 17-Bunker pump, 18-Discharge valve, 19-Ash quantity regulating device, 20-Inlet valve, 21-Fly ash supplementary airflow valve;
[0030] 91-Central air duct, 92-Coal and biomass coupled air-powder channel, 93-Supplemental primary air-powder ash airflow channel, 94-Air-powder airflow guide plate, 95-Secondary airflow guide plate, 96-Supplemental primary fly ash air-powder airflow regulating baffle. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of this technical solution clearer, the following detailed description, in conjunction with specific embodiments, further illustrates this technical solution. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this technical solution.
[0032] Example 1
[0033] like Figure 1 As shown, this embodiment proposes a fly ash-supplemented coal-biomass coupled combustion device 9, including a central air duct 91, a coal-biomass coupled air-powder channel 92, and a supplementary primary air-powder ash airflow channel 93. The coal-biomass coupled air-powder channel 92 is fitted outside the central air duct 91, and the output ends of the central air duct 91 and the coal-biomass coupled air-powder channel 92 are in the same direction and coaxially arranged. The supplementary primary air-powder ash airflow channel 93 is fitted outside the coal-biomass coupled air-powder channel 92, and the output ends of the supplementary primary air-powder ash airflow channel 93 and the coal-biomass coupled air-powder channel 92 are in the same direction and coaxially arranged.
[0034] The tail end of the main body of the primary air and fly ash airflow channel 93 is open. Near the front end of the primary air and fly ash airflow channel 93, there is an outer input ring sleeve. The input ring sleeve is sealed to the outer wall of the main body of the primary air and fly ash airflow channel 93. The front end of the primary air and fly ash airflow channel 93 is provided with a primary air and fly ash airflow regulating baffle 96 corresponding to the inner cavity of the input ring sleeve.
[0035] Preferably, the inner diameter of the rear section of the coal-biomass coupling air-powder channel 92 installed in the central air duct 91 is larger than that of the front section, and the middle part of the coal-biomass coupling air-powder channel 92 installed in the central air duct 91 is a bucket-shaped narrow section, which has an air-powder airflow guide plate 94 for spiral output of air-powder airflow.
[0036] Similarly, the fly ash supplemental coal and biomass coupled combustion device also includes a secondary air duct. The main body of the secondary air duct is fitted into the rear section of the coal and biomass coupled air-powder channel 92, and its inner diameter is larger than that of the front section. The middle part of the secondary air duct is fitted into the middle section of the coal and biomass coupled air-powder channel 92, which is a bucket-shaped narrowing section with a secondary air guide plate.
[0037] When this fly ash-supplemented coal-biomass coupled combustion device 9 is in use, the central air duct 91 is used to introduce pressurized air, and the coal-biomass coupling air-powder channel 92 is used to transport the mixture of coal and biomass powder after coupling. Due to the carrying effect of the central air duct 91, the mixture of coal and biomass powder can be synchronously ejected from the right end through the pressurized gas. Similarly, the primary air fly ash airflow channel 93 can simultaneously eject the coal ash input through its input ring from the right end through the pressurized gas transported by the central air duct 91.
[0038] During the above process, since the rear end of the primary air fly ash airflow channel 93 is flared and open, ambient air can enter the interior of the horizontally placed pipe of the primary air fly ash airflow channel 93 through the open rear end of the primary air fly ash airflow channel 93.
[0039] In the above process, due to the presence of the air-powder airflow guide plate 94, the pulverized coal and biomass fuel passing through the air-powder airflow guide plate 94 can achieve two effects: firstly, it compresses the air-powder airflow, making the airflow velocity faster, and secondly, it guides the air-powder airflow to form a cyclone airflow. Finally, the cyclone gas containing pulverized coal and biomass, wrapped in a pressurized gas outer layer, is ejected from the right port of the device.
[0040] Similarly, in the above process, after the compressed air enters the primary air-fly ash airflow channel 93, it will be guided by the secondary air guide plate 95 to form a faster cyclone airflow from the ambient air that enters through the open right end of the primary air-fly ash airflow channel 93, and finally be ejected from the right port of the device.
[0041] Preferably, the front end of the secondary air duct is flared, and the primary fly ash airflow regulating baffle 96 is located at the flared end of the secondary air duct. The output port of the coal-biomass coupling air-powder channel 92 is located in front of the output port of the central air duct 91, and the output end of the coal-biomass coupling air-powder channel 92 is located behind the starting position of the flared section at the front end of the secondary air duct. The flared shape at the front end of the secondary air duct guides the cyclone ejection, preventing interference between the ejection end of the primary fly ash airflow channel 93 and the ejected mixed gas.
[0042] The axis of the central air duct 91 coincides with the axis of the fly ash-supplemented coal-biomass coupled combustion device 9. The central air velocity should not be too high. This increases the rigidity of the coal-biomass coupled air while preventing coal dust scattering, allowing the airflow to form an internal circulation, stabilizing ignition, and ensuring that the fly ash airflow does not damage the flame in the main combustion zone. Coal dust and biomass fuel are carried by the coal-biomass coupled air and mixed in advance to form an air-coal-fuel airflow, which enters the combustion device through the coal-biomass coupled air-coal-fuel channel 92.
[0043] Example 2
[0044] like Figure 2 As shown, this embodiment proposes a fly ash-supplemented coal-biomass coupled combustion system, using the fly ash-supplemented coal-biomass coupled combustion device 9 as proposed in Embodiment 1. The fly ash-supplemented coal-biomass coupled combustion system also includes a pulverized coal conveying component, a biomass powder conveying component, and a fly ash powder conveying component. The fly ash-supplemented coal-biomass coupled combustion device 9 is installed in the combustion chamber of the boiler 10. The output ends of the pulverized coal conveying component and the biomass powder conveying component are connected to the input end of the coal-biomass coupled air-powder channel 92 of the fly ash-supplemented coal-biomass coupled combustion device 9 after mixing. The output end of the fly ash powder conveying component is connected to the inside of the input ring of the supplementary primary air-fly ash airflow channel 93.
[0045] The pulverized coal conveying assembly includes a raw coal bunker 1, a coal feeder 2, and a coal mill 3. The output end of the raw coal bunker 1 is connected to the coal mill 3 via the coal feeder 2, and the output end of the coal mill 3 is connected to a fly ash-supplemented coal-biomass coupled combustion device 9. After the raw coal is discharged from the raw coal bunker 1, it is conveyed to the coal mill 3 via the coal feeder 2. The coal mill 3 performs fine grinding on the raw coal, so that the raw coal reaches the expected particle size of pulverized coal.
[0046] In this embodiment, the biomass powder conveying assembly includes a biomass storage silo 4, a primary distributor 51, a secondary distributor 52, a crusher 6, a mill 7, and a feeder 8. The output end of the biomass storage silo 4 is connected to the input end of the primary distributor 51, and the output end of the primary distributor 51 is connected to the crusher 6. The output end of the crusher 6 is connected to the mill 7 via the secondary distributor 52, and the output end of the mill 7 is connected to the fly ash-supplemented coal-biomass coupled combustion device 9 via the feeder 8. First, biomass from the biomass storage silo 4 enters the primary distributor 51. After preliminary crushing by the crusher 6, it forms short segments of biomass material. These short segments then enter the secondary distributor 52 and subsequently the crusher 6. After passing through the crusher 6, the short segments of biomass reach the desired particle size for biomass powder.
[0047] The biomass powder and coal powder that have reached the expected particle size are coupled and then transported to the coal and biomass coupling air-powder channel 92 of the fly ash supplemented coal and biomass coupled combustion device 9.
[0048] A dust collector hopper 16 is installed at the flue gas emission end of boiler 10. The ash powder conveying assembly includes a silo pump 17, an ash quantity regulating device 19, and a compressed air station. The output end of the dust collector hopper 16 is connected to the input end of the silo pump 17. The ash quantity regulating device 19 is located at the output end of the silo pump 17. The output end of the compressed air station is connected to the output end of the silo pump 17. Part of the outlet of the silo pump 17 is conveyed to the ash field via compressed air, and the other part is carried to the fly ash supplementary coal and biomass coupled combustion device 9 via supplementary primary hot air. Boiler 10 has an external flue gas circulation duct. The output end of the fly ash powder conveying assembly also has a preheating flue. Parts of the pipes of the preheating flue and the external flue gas circulation duct are connected to the supplementary primary air preheater 12. The supplementary primary air preheater 12 preheats the output material in the preheating flue through the external flue gas circulation duct.
[0049] Specifically, in the aforementioned fly ash-supplemented coal-biomass coupled combustion system, a high-temperature gas circulation pipe is provided on the side of the boiler 10. A supplementary primary air preheater 12 is provided on the high-temperature gas circulation pipe between the boiler 10 and the supplementary primary air preheater 12. A supplementary primary air preheater flue gas inlet baffle 11 and a supplementary primary air preheater outlet flue gas check baffle 13 are respectively provided on the pipes corresponding to the input and output ends of the supplementary primary air preheater 12. The supplementary primary air preheater flue gas inlet baffle 11 and the supplementary primary air preheater outlet flue gas check baffle 13 can respectively control the corresponding opening and closing states of the pipes.
[0050] Additionally, a hopper pump 17 is installed at the bottom of the dust collector hopper 16, and an ash quantity regulating device 19 is installed at the output end of the hopper pump 17. This ash quantity regulating device 19 can adjust the output ash quantity. The compressed air station is connected to the ash quantity regulating device 19 through a pipeline. An air inlet valve 20 is installed on the pipeline between the compressed air station and the ash quantity regulating device 19. One output end of the ash quantity regulating device 19 is connected to the ash discharge yard through a pipeline. A discharge valve 18 is installed on this pipeline for discharging excess ash. The other output end of the ash quantity regulating device 19 is connected to the supplementary primary air fly ash airflow channel 93 of the fly ash supplementary coal and biomass coupled combustion device 9 through a pipeline. A fly ash supplementary airflow valve 21 is installed on this pipeline.
[0051] The compressed air station and intake valve 20 also have a branch pipe that connects to the supplementary primary air preheater 12, and the return pipe connected to this pipe is connected to the pipe between the fly ash supplementary airflow valve 21 and the fly ash supplementary coal and biomass coupled combustion device 9. This circulation loop is used to preheat the supplementary primary air, and in this circulation, supplementary primary air outlet baffle 14 and supplementary primary air inlet baffle 15 are respectively installed on the two pipes at the input and output ends of the supplementary primary air preheater 12.
[0052] like Figures 3-7 As shown, using a fly ash-supplemented coal-biomass coupled combustion device 9, the composition of the deposited ash sample was analyzed. The alkali metal K content was significantly increased. The biomass to fly ash blending ratio was 1:1 (based on biomass ash content and fly ash content). At 980℃, the K content increased from 5.5 to 14.22, indicating a significant enhancement in ash solidification K capacity. Analysis of the microstructure of the ash sample under biomass and fly ash blending conditions revealed increased particle spacing, a distinct layered structure, and easier removal. In a fly ash-supplemented coal-biomass coupled combustion system experiment using lignite and rice husks as raw materials, the alkali metal K content in the deposited ash was significantly increased. Further analysis revealed an increase in the content of high-melting-point K-Al-Si composite salts. Supplementing with fly ash solidifies the alkali metals within these high-melting-point composite salts, improving slagging on the boiler 10 heating surface. The resulting ash agglomeration was reduced, and the increased spacing facilitated soot blowing.
[0053] The above content is only a preferred embodiment of the present invention. For those skilled in the art, many changes can be made in the specific implementation and application scope based on the ideas of the present invention. As long as these changes do not depart from the concept of the present invention, they all fall within the protection scope of this patent.
Claims
1. A fly ash-supplemented coal-biomass coupled combustion device, characterized in that: It includes a central air duct, a coal-biomass coupled air-powder channel, and a supplementary primary air-powder fly ash airflow channel. The coal-biomass coupled air-powder channel is fitted outside the central air duct, and the output ends of the central air duct and the coal-biomass coupled air-powder channel are in the same direction and coaxially arranged. The supplementary primary air-powder fly ash airflow channel is fitted outside the coal-biomass coupled air-powder channel, and the output ends of the supplementary primary air-powder fly ash airflow channel and the coal-biomass coupled air-powder channel are in the same direction and coaxially arranged. The tail end of the main body of the supplementary primary air fly ash airflow channel is open. Near the front end of the supplementary primary air fly ash airflow channel, there is an outer input ring sleeve. The input ring sleeve is sealed to the outer wall of the main body of the supplementary primary air fly ash airflow channel. At the front end of the main body of the supplementary primary air fly ash airflow channel, corresponding to the inner cavity of the input ring sleeve, there is a supplementary primary air fly ash airflow regulating baffle.
2. The fly ash-supplemented coal-biomass coupled combustion device according to claim 1, characterized in that: The inner diameter of the rear section of the coal-biomass coupling air-powder channel is larger than that of the front section of the central air duct. The middle section of the coal-biomass coupling air-powder channel is a bucket-shaped narrowing section with a guide plate for spiral output of the air-powder airflow.
3. The fly ash-supplemented coal-biomass coupled combustion device according to claim 1, characterized in that: The fly ash supplemental coal and biomass coupled combustion device also includes a secondary air duct. The inner diameter of the secondary air duct is larger than that of the front section of the coal and biomass coupled air-powder channel. The main body of the secondary air duct is fitted in the middle of the coal and biomass coupled air-powder channel, forming a bucket-shaped narrow section. This narrow section has a secondary air guide plate.
4. The fly ash-supplemented coal-biomass coupled combustion device according to claim 3, characterized in that: The front end of the secondary air duct is flared, and the supplementary primary fly ash airflow regulating baffle is set at the flared part of the secondary air duct.
5. The fly ash-supplemented coal-biomass coupled combustion device according to claim 4, characterized in that: The output port of the coal and biomass coupled air-powder channel is located in front of the output port of the central air duct, and the output end of the coal and biomass coupled air-powder channel is located behind the starting position of the front end flared section of the main body of the supplementary primary air-powder fly ash airflow channel.
6. A fly ash-supplemented coal-biomass coupled combustion system, characterized in that: Using the fly ash-supplemented coal-biomass coupled combustion device as described in any one of claims 1-5, the fly ash-supplemented coal-biomass coupled combustion system further includes a pulverized coal conveying component, a biomass pulverized coal conveying component, and a fly ash pulverized coal conveying component. The fly ash-supplemented coal-biomass coupled combustion device is installed in the boiler combustion chamber. The output ends of the pulverized coal conveying component and the biomass pulverized coal conveying component are connected to the input end of the coal-biomass coupled air-powder channel of the fly ash-supplemented coal-biomass coupled combustion device after mixing. The output end of the fly ash pulverized coal conveying component is connected to the inside of the input ring of the supplementary primary air-powdered fly ash airflow channel.
7. The fly ash-supplemented coal-biomass coupled combustion system according to claim 6, characterized in that: The pulverized coal conveying assembly includes a raw coal bunker, a coal feeder, and a coal mill. The output end of the raw coal bunker is connected to the coal mill via the coal feeder, and the output end of the coal mill is connected to a fly ash-supplemented coal-biomass coupled combustion device.
8. The fly ash-supplemented coal-biomass coupled combustion system according to claim 6, characterized in that: The biomass powder conveying assembly includes a biomass storage silo, a primary distributor, a secondary distributor, a crusher, a grinding mill, and a feeder. The output end of the biomass storage silo is connected to the input end of the primary distributor, the output end of the primary distributor is connected to the crusher, the output end of the crusher is connected to the grinding mill through the secondary distributor, and the output end of the grinding mill is connected to a fly ash-supplemented coal-biomass coupled combustion device through the feeder.
9. The fly ash-supplemented coal-biomass coupled combustion system according to claim 6, characterized in that: The flue gas emission end of the boiler is equipped with a dust collector ash hopper. The ash powder conveying assembly includes a hopper pump, an ash quantity regulating device, and a compressed air station. The output end of the dust collector ash hopper is connected to the input end of the hopper pump. The ash quantity regulating device is located at the output end of the hopper pump. The output end of the compressed air station is connected to the output end of the hopper pump. Part of the hopper pump outlet is transported to the ash field by compressed air, and the other part is carried to the fly ash supplemental coal and biomass coupled combustion device by supplemental primary hot air.
10. The fly ash-supplemented coal-biomass coupled combustion system according to claim 9, characterized in that: The boiler has an external flue gas circulation duct, and the output end of the coal ash powder conveying assembly also has a preheating flue. Parts of the pipes of the preheating flue and the external flue gas circulation duct are connected to a supplementary primary air preheater. The supplementary primary air preheater preheats the output material in the preheating flue through the external flue gas circulation duct.