Powder feeding system and boiler

Abstract

The present invention proposes a powder feeding system and a boiler. The powder feeding system of the present invention includes a first silo, the first silo has a first discharge outlet; a first discharge device, the inlet of the first discharge device is connected to the first discharge outlet; a second silo, the second silo has a second discharge outlet; a second discharge device, the inlet of the second discharge device is connected to the second discharge outlet; a first air-powder mixer, the first air-powder mixer has a first powder inlet, a first air inlet and a first outlet; a second air-powder mixer, the second air-powder mixer has a second powder inlet, a second air inlet and a second outlet, the outlet of the first discharge device is selectively connected to the first powder inlet and the second powder inlet, and the outlet of the second discharge device is selectively connected to the first powder inlet and the second powder inlet; and a discharge pipe. The powder feeding system of the present invention has the advantages of being able to easily mix and feed two powder materials in proportion, facilitating feeding and reducing pollution.

Description

Technical Field

[0001] The invention relates to the technical field of boiler feeding, and in particular to a powder feeding system and a boiler. Background Art

[0002] Pulverized coal industrial boilers produce a high level of harmful gases when burning fuel. To protect the environment, adding biomass powder to the fuel is an effective way and important means to reduce carbon dioxide, nitrogen, and sulfur emissions. Biomass primarily refers to wood cellulose (lignin) from straw, trees, and other sources other than grain and fruit produced during agricultural and forestry production, as well as waste from agricultural and forestry processing, agricultural and forestry waste, and livestock manure and waste from animal husbandry. Prior art methods for directly adding biomass powder to blue carbon powder in the powder silo make it difficult to control the ratio of blue carbon powder to biomass powder during combustion, resulting in unstable combustion. Summary of the Invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, embodiments of the present invention provide a powder feeding system and a boiler.

[0004] The powder feeding system of the embodiment of the present invention includes:

[0005] a first silo, the first silo being used to store a first powder, and the first silo having a first discharge outlet;

[0006] a first unloading device, wherein the inlet of the first unloading device is connected to the first unloading outlet, and the first unloading device can be used to control the flow rate of the first unloading outlet;

[0007] a second silo, the second silo being used to store a second powder, and the second silo having a second discharge outlet;

[0008] a second unloading device, wherein the inlet of the second unloading device is connected to the second unloading outlet, and the second unloading device can be used to control the flow rate of the second unloading outlet;

[0009] a first air-powder mixer, the first air-powder mixer having a first powder inlet, a first air inlet, and a first outlet, and the first air-powder mixer can mix the powder and air entering therein and discharge the mixed powder from the first outlet;

[0010] a second air-powder mixer, the second air-powder mixer having a second powder inlet, a second air inlet, and a second outlet. The second air-powder mixer can mix the powder and air entering therein and discharge the mixed powder from the second outlet. The outlet of the first discharge device is selectively connected to the first powder inlet and the second powder inlet. The outlet of the second discharge device is selectively connected to the first powder inlet and the second powder inlet. The second outlet of the second air-powder mixer is connected to the first air inlet of the first air-powder mixer.

[0011] The discharge pipe, the first outlet and the second outlet are both connected to the inlet of the discharge pipe.

[0012] Therefore, the powder feeding system according to the embodiment of the present invention has the advantages of being able to mix and feed two powders in proportion, facilitating feeding and reducing pollution.

[0013] In some embodiments, the outlet of the first discharge device is in communication with the first powder inlet, and the outlet of the second discharge device is selectively in communication with the first powder inlet and the second powder inlet.

[0014] The powder feeding system of the embodiment of the present invention includes

[0015] a first pipeline, wherein the outlet of the first pipeline is connected to the first powder inlet, the outlet of the second unloading device is connected to the inlet of the first pipeline, and a first valve for controlling the opening and closing of the first pipeline is provided at the inlet of the first pipeline;

[0016] The second pipeline, the outlet of the second pipeline is connected to the second powder inlet, the outlet of the second unloading device is connected to the inlet of the second pipeline, and a second valve for controlling its opening and closing is provided at the inlet of the second pipeline.

[0017] In some embodiments, a stirrer is provided in the second silo, the stirrer comprising a stirring shaft and a plurality of stirring parts provided on the stirring shaft, the stirring parts being column-shaped or blade-shaped;

[0018] The first powder is blue carbon powder or coal powder, and the second powder is biomass powder.

[0019] The powder feeding system of the embodiment of the present invention includes a fan, and the outlet of the fan is connected to the second air inlet of the second air-powder mixer.

[0020] In some embodiments, the first discharge outlet is provided at the bottom of the first silo, the second discharge outlet is provided at the bottom of the second silo, the first discharge device is a discharge valve or a screw feeder, and the second discharge device is a discharge valve or a screw feeder.

[0021] In some embodiments, the first air-powder mixer and the second air-powder mixer both include

[0022] a feed chute having a powder inlet and a powder outlet;

[0023] A mixing tube, the mixing tube comprising a third tube, a fourth tube and a fifth tube connected in sequence, the axial directions of the third tube, the fourth tube and the fifth tube being consistent, the inlet of the third tube being an air inlet, the diameter of the third tube decreasing in the axial direction of the third tube in the direction adjacent to the fourth tube, the diameter of the fourth tube being less than or equal to the diameter of the third tube and the diameter of the fifth tube, the diameter of the fifth tube increasing in the axial direction of the fifth tube in the direction away from the fourth tube, and the fourth tube being provided with an inlet connected to the powder outlet.

[0024] The powder feeding system of the embodiment of the present invention further includes

[0025] a first cover and a first feeding device, wherein the first feeding device can transport the first powder into the first silo, and the first feeding device, the first silo, the first discharge device and the first air-powder mixer are all located in the first cover;

[0026] The second cover body and the second feeding device are capable of conveying the second powder into the second silo. The second feeding device, the second silo, the second unloading device and the second air-powder mixer are all located in the second cover body.

[0027] The present invention also provides a boiler, comprising:

[0028] A boiler body, the boiler body including a furnace;

[0029] a burner, wherein an outlet of the burner is in communication with the furnace;

[0030] A powder feeding system, wherein the powder feeding system is the above-mentioned powder feeding system, and the powder feeding system comprises a discharge pipe, and the outlet of the discharge pipe is connected to the inlet of the burner. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of a powder feeding system according to an embodiment of the present invention.

[0032] Figure 2 2 is a schematic diagram of a first air-powder mixer according to an embodiment of the present invention.

[0033] Reference numerals:

[0034] Powder feeding system 100;

[0035] First silo 1, first discharge outlet 11, first discharge device 12;

[0036] Second silo 2, second discharge outlet 21, second discharge device 22, first pipeline 23, second pipeline 24;

[0037] First air-powder mixer 3, first powder inlet 31, first air inlet 32, first outlet 33;

[0038] Second air-powder mixer 4, second powder inlet 41, second air inlet 42, second outlet 43;

[0039] Discharge pipe 5;

[0040] Fan 6;

[0041] Burner 7;

[0042] Feed trough 81, powder inlet 82, third tube 83, fourth tube 84, fifth tube 85. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0044] The powder feeding system 100 according to an embodiment of the present invention will be described below with reference to the accompanying drawings. Figure 1 and Figure 2 As shown, the powder feeding system 100 according to an embodiment of the present invention includes a first silo 1, a first unloading device 12, a second silo 2, a second unloading device 22, a first air-powder mixer 3, a second air-powder mixer 4 and a discharge pipe 5.

[0045] The first silo 1 is used to store the first powder and has a first discharge outlet 11 . The inlet of the first discharge device 12 is connected to the first discharge outlet 11 , and the first discharge device 12 can be used to control the flow of the first discharge outlet 11 .

[0046] The second silo 2 is used to store the second powder and has a second discharge outlet 21 . The inlet of the second discharge device 22 is connected to the second discharge outlet 21 , and the second discharge device 22 can be used to control the flow of the second discharge outlet 21 .

[0047] The first air-powder mixer 3 has a first powder inlet 31, a first air inlet 32, and a first outlet 33. The first air-powder mixer 3 mixes the powder entering it with air and discharges it from the first outlet 33. The second air-powder mixer 4 has a second powder inlet 41, a second air inlet 42, and a second outlet 43. The second air-powder mixer 4 mixes the powder entering it with air and discharges it from the second outlet 43. The outlet of the first discharge device 12 selectively communicates with the first powder inlet 31 and the second powder inlet 41, and the outlet of the second discharge device 22 selectively communicates with the first powder inlet 31 and the second powder inlet 41. The first outlet 33 and the second outlet 43 both communicate with the inlet of the discharge pipe 5.

[0048] The powder feeding system 100 according to an embodiment of the present invention comprises a first silo 1 and a second silo 2. A first discharge device 12 is used to control the flow rate of the first discharge outlet 11, and a second discharge device 22 is used to control the flow rate of the second discharge outlet 21. This allows the flow rate (amount discharged per unit time) of the first powder exiting the first silo 1 to be adjusted, and the flow rate of the second powder exiting the second silo 2 to be adjusted. This allows the powder feeding system 100 to supply only the first or second powder, or to discharge the first and second powders in a preset ratio and convey them to the burner 7 for combustion. Specifically, the first powder is blue coke powder or coal powder, and the second powder is biomass powder. Biomass powder is flammable and can reduce pollution. Mixing biomass powder with blue coke powder or coal powder in a specific ratio facilitates the combustion of blue coke powder and coal powder, achieving carbon neutrality and reducing the production of pollutants.

[0049] The first air-powder mixer 3 can mix the powder entering it with air and discharge it from the first outlet 33. The second air-powder mixer 4 can mix the powder entering it with air and discharge it from the second outlet 43. This allows the first and second air-powder mixers 3 and 3 to mix air with powder and then transport the mixed air to the burner 7 through the discharge pipe 5 for combustion, thereby facilitating the combustion of the powder. Furthermore, the outlet of the first discharge device 12 selectively communicates with the first powder inlet 31 and the second powder inlet 41, and the outlet of the second discharge device 22 selectively communicates with the first powder inlet 31 and the second powder inlet 41. In other words, both the first and second powders can enter the first air-powder mixer 3 or the second air-powder mixer 4 and mix with air. This facilitates mixing the two powders (the first and second powders) in a certain proportion and feeding them. Moreover, when the first silo 1 or the second silo 2 is out of material or blocked, or when the first air-powder mixer 3 or the second air-powder mixer 4 fails, the powder (one of the first powder and the second powder) can still be mixed with the air and enter the discharge pipe 5, thereby making the powder feeding system 100 less likely to break, facilitating feeding, and increasing the fault tolerance of the powder feeding system 100.

[0050] Therefore, the powder feeding system 100 according to the embodiment of the present invention has the advantages of being able to mix and feed two powders in proportion, facilitating feeding and reducing pollution.

[0051] like Figure 1 and Figure 2 As shown, the powder feeding system 100 according to an embodiment of the present invention includes a first silo 1, a first unloading device 12, a second silo 2, a second unloading device 22, a first air-powder mixer 3, a second air-powder mixer 4, a discharge pipe 5 and a fan 6.

[0052] A first silo 1 is mounted on a frame and is used to store a first powder. The first silo 1 has a first discharge outlet 11. Specifically, the first discharge outlet 11 is located at the bottom of the first silo 1. A material inlet is located at the top of the first silo 1. After entering the first silo 1, the first powder is discharged from the first discharge outlet 11 at the bottom. For example, the first powder is blue coke powder.

[0053] The inlet of the first discharge device 12 is connected to the first discharge outlet 11. The first discharge device 12 can be used to control the flow rate of the first discharge outlet 11. The first discharge device 12 is a discharge valve or a screw feeder. Specifically, the first discharge device 12 is a discharge valve and is located below the first silo 1 to facilitate the entry of the first powder in the first silo 1 into the first discharge device 12. For example, the first discharge device 12 is a star-shaped feed valve, which facilitates the adjustment of the flow rate (mass or fluid volume per unit time) of the first powder discharged from the first discharge outlet 11.

[0054] Second silo 2 is used to store a second powder and has a second discharge outlet 21. Specifically, second silo 2 is mounted on a frame, with second discharge outlet 21 located at the bottom of second silo 2. A material inlet is provided at the top of second silo 2. After entering second silo 2, the second powder is discharged from second discharge outlet 21 at the bottom. For example, the second powder is biomass powder.

[0055] A stirrer is provided within the second silo 2. The stirrer comprises a stirring shaft and a plurality of stirring sections disposed on the stirring shaft. The stirring sections are cylindrical or blade-shaped. Specifically, the stirring shaft has an axial direction extending in an up-and-down direction. Rotation of the stirring shaft drives the stirring sections thereon to rotate, thereby stirring the biomass powder. This prevents accumulation of lighter biomass powder and facilitates discharge of the biomass powder from the second silo 2 through the second discharge outlet 21. For example, the stirring sections may be cylindrical, extending in the same direction as the radial direction of the stirring shaft.

[0056] The inlet of the second discharge device 22 is connected to the second discharge outlet 21. The second discharge device 22 can be used to control the flow rate of the second discharge outlet 21. The second discharge device 22 is a discharge valve or a screw feeder. The second discharge device 22 is a discharge valve and is located below the second silo 2 to facilitate the flow of the second powder in the second silo 2 into the second discharge device 22. For example, the second discharge device 22 is a star-shaped feed valve, which facilitates the adjustment of the flow rate of the second powder discharged from the second discharge outlet 21.

[0057] The first air-powder mixer 3 has a first powder inlet 31, a first air inlet 32, and a first outlet 33. The first air-powder mixer 3 mixes the powder entering it with air and discharges it from the first outlet 33. The second air-powder mixer 4 has a second powder inlet 41, a second air inlet 42, and a second outlet 43. The second air-powder mixer 4 mixes the powder entering it with air and discharges it from the second outlet 43. Powder can enter the first air-powder mixer 3 through the first powder inlet 31, and powder can enter the second air-powder mixer 4 through the second powder inlet 41.

[0058] like Figure 2 As shown, specifically, the first air-powder mixer 3 and the second air-powder mixer 4 each include a feed trough 81 and a mixing tube. The mixing tube is a venturi tube, which facilitates mixing of the powder and air. The feed trough 81 has a powder inlet 82 and a powder outlet. The powder inlet 82 is located above the powder outlet, and the powder can enter the feed trough 81 through the powder inlet 82.

[0059] The mixing tube includes a third tube 83 (the converging section of the mixing tube), a fourth tube 84 (the throat of the mixing tube), and a fifth tube 85 (the diverging section of the mixing tube), which are connected in sequence. The third, fourth, and fifth tubes 83, 84, and 85 are axially aligned. The inlet of the third tube 83 serves as the air inlet, and the outlet of the third tube 83 is connected to the fourth tube 84. The diameter of the third tube 83 decreases axially toward the fourth tube 84. The diameter of the fourth tube 84 is equal to or smaller than the diameters of the third and fourth tubes 83 and 85. The diameter of the fifth tube 85 increases axially away from the fourth tube 84. The fourth tube 84 is provided with an inlet connected to the powder outlet. This allows air to enter the fourth tube 84 from the third tube 83, mix with the powder, and then be discharged from the fifth tube 85. For example, the axial directions of the third, fourth, and fifth tubes 83, 84, and 85 are left-right, with the diameter of the third tube 83 decreasing from left to right and the diameter of the fifth tube 85 increasing from left to right.

[0060] Optionally, a stirring device is provided in the feed trough 81 so that the powder in the feed trough 81 can be easily discharged from the feed trough 81 through the powder outlet.

[0061] The powder inlet 82 of the first air-powder mixer 3 constitutes the first powder inlet 31, the inlet of the third tube 83 of the first air-powder mixer 3 constitutes the first air inlet 32, and the outlet of the fifth tube 85 of the first air-powder mixer 3 constitutes the first outlet 33. The powder inlet 82 of the second air-powder mixer 4 constitutes the second powder inlet 41, the inlet of the third tube 83 of the second air-powder mixer 4 constitutes the second air inlet 42, and the outlet of the fifth tube 85 of the second air-powder mixer 4 constitutes the second outlet 43.

[0062] The first outlet 33 and the second outlet 43 are both communicated with the inlet of the discharge pipe 5. For example, the first outlet 33 and the second outlet 43 are respectively communicated with the inlet of the discharge pipe 5 through a pipe, and the outlet of the discharge pipe 5 is communicated with the inlet of the burner 7.

[0063] The outlet of the first discharge device 12 selectively communicates with the first powder inlet 31 and the second powder inlet 41, and the outlet of the second discharge device 22 selectively communicates with the first powder inlet 31 and the second powder inlet 41. The outlet of the first discharge device 12 selectively communicates with the first powder inlet 31 and the second powder inlet 41, and the outlet of the second discharge device 22 selectively communicate with the first powder inlet 31 and the second powder inlet 41 include: a. The outlet of the first discharge device 12 communicates with the first powder inlet 31, and the outlet of the second discharge device 22 communicates with the first powder inlet 31; b. The outlet of the first discharge device 12 communicates with the second powder inlet 41, and the outlet of the second discharge device 22 communicates with the second powder inlet 41; c. The outlet of the first discharge device 12 communicates with the first powder inlet 31, and the outlet of the second discharge device 22 communicates with the second powder inlet 41; d. The outlet of the first discharge device 12 communicates with the second powder inlet 41, and the outlet of the second discharge device 22 communicates with the first powder inlet 31.

[0064] like Figure 1 As shown, in some embodiments, the outlet of the first discharge device 12 is connected to the first powder inlet 31, and the outlet of the second discharge device 22 is selectively connected to the first powder inlet 31 and the second powder inlet 41. The outlet of the first discharge device 12 is connected to the first powder inlet 31, and the outlet of the second discharge device 22 is selectively connected to the first powder inlet 31 and the second powder inlet 41, including: a. The outlet of the first discharge device 12 is connected to the first powder inlet 31, and the outlet of the second discharge device 22 is connected to the first powder inlet 31, thereby, when the second air-powder mixer 4 stops working, the first powder and the second powder can be mixed in the feed trough 81 of the first air-powder mixer 3 and then mixed with the air; b. The outlet of the first discharge device 12 is connected to the first powder inlet 31, and the outlet of the second discharge device 22 is connected to the second powder inlet 41, that is, the first powder is mixed with the air in the first air-powder mixer 3, and the second powder is mixed with the air in the second air-powder mixer 4, so that the first powder and the air are mixed evenly, and the second powder and the air are mixed evenly.

[0065] In some embodiments, the powder feeding system 100 includes a first pipe 23 and a second pipe 24 .

[0066] The outlet of the first pipe 23 is connected to the first powder inlet 31, and the outlet of the second discharge device 22 is connected to the inlet of the first pipe 23. A first valve is provided at the inlet of the first pipe 23 to control its opening and closing. The outlet of the second pipe 24 is connected to the second powder inlet 41, and the outlet of the second discharge device 22 is connected to the inlet of the second pipe 24. A second valve is provided at the inlet of the second pipe 24 to control its opening and closing. Thus, the outlet of the second discharge device 22 can be connected to the second powder inlet 41 by controlling the opening of the first valve, and the outlet of the second discharge device 22 can be connected to the first powder inlet 31 by controlling the opening of the second valve. For example, the inlet of the first pipe 23 is located above the outlet of the second pipe, and the inlet of the second pipe 24 is located above the outlet of the second pipe 24, allowing powder to move within the first and second pipes 23 and 24 by gravity.

[0067] like Figure 1 As shown, in some embodiments, the second outlet 43 of the second air-powder mixer 4 is connected to the first air inlet 32 ​​of the first air-powder mixer 3. As a result, the second powder can be mixed with the air in the second air-powder mixer 4, enter the second air-powder mixer 3 through the first air inlet 32, and then be mixed with the first powder, so that the first powder and the second powder can be mixed more evenly.

[0068] The outlet of the fan 6 is connected to the second air inlet 42 of the second air-powder mixer 4. As a result, air can enter the second air-powder mixer 4 from the second air inlet 42 and mix with the second powder. In addition, the second outlet 43 of the second air-powder mixer 4 is connected to the first air inlet 32 ​​of the first air-powder mixer 3. This allows air to enter the second air-powder mixer 3 from the first air inlet 32 ​​and then mix with the first powder. This can make the first powder and the second powder more evenly mixed, and can reduce the number of fans 6, thereby reducing costs.

[0069] The powder feeding system 100 further includes a first cover, a first feeding device, a second cover, and a second feeding device.

[0070] The first feeding device can convey the first powder into the first silo 1. The first feeding device, the first silo 1, the first discharge device 12, and the first air-powder mixer 3 are all located within the first housing. The first housing can protect the first feeding device, the first silo 1, the first discharge device 12, and the first air-powder mixer 3.

[0071] The second feeding device can convey the second powder into the second silo 2. The second feeding device, the second silo 2, the second discharge device 22, and the second air-powder mixer 4 are all located within the second housing. The second housing can protect the second feeding device, the second silo 2, the second discharge device 22, and the second air-powder mixer 4. For example, both the first feeding device and the second feeding device are electric hoists.

[0072] The present invention also provides a boiler, which includes a boiler body, a burner 7, and a powder feeding system 100 according to an embodiment of the present invention. The boiler body includes a furnace, and the outlet of the burner 7 is connected to the furnace. The powder feeding system 100 according to an embodiment of the present invention includes a discharge pipe 5, the outlet of the discharge pipe 5 being connected to the inlet of the burner 7.

[0073] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 should not be understood as limiting the present invention.

[0074] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0075] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0076] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0077] In the present invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless they are mutually inconsistent.

[0078] Although the above embodiments have been shown and described, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those skilled in the art are all within the scope of protection of the present invention.

Claims

1. A powder feeding system, characterized in that: include: a first silo, the first silo being used to store a first powder, and the first silo having a first discharge outlet; a first unloading device, wherein the inlet of the first unloading device is connected to the first unloading outlet, and the first unloading device can be used to control the flow rate of the first unloading outlet; a second silo, the second silo being used to store a second powder, and the second silo having a second discharge outlet; a second unloading device, wherein the inlet of the second unloading device is connected to the second unloading outlet, and the second unloading device can be used to control the flow rate of the second unloading outlet; a first air-powder mixer, the first air-powder mixer having a first powder inlet, a first air inlet, and a first outlet, and the first air-powder mixer can mix the powder and air entering therein and discharge the mixed powder from the first outlet; a second air-powder mixer, the second air-powder mixer having a second powder inlet, a second air inlet, and a second outlet. The second air-powder mixer can mix the powder and air entering therein and discharge the mixed powder from the second outlet. The outlet of the first discharge device is selectively connected to the first powder inlet and the second powder inlet. The outlet of the second discharge device is selectively connected to the first powder inlet and the second powder inlet. The second outlet of the second air-powder mixer is connected to the first air inlet of the first air-powder mixer. The discharge pipe, the first outlet and the second outlet are both connected to the inlet of the discharge pipe.

2. The powder feeding system according to claim 1, characterized in that: The outlet of the first discharge device is in communication with the first powder inlet, and the outlet of the second discharge device is selectively in communication with the first powder inlet and the second powder inlet.

3. The powder feeding system according to claim 2, characterized in that: include a first pipeline, wherein the outlet of the first pipeline is connected to the first powder inlet, the outlet of the second unloading device is connected to the inlet of the first pipeline, and a first valve for controlling the opening and closing of the first pipeline is provided at the inlet of the first pipeline; The second pipeline, the outlet of the second pipeline is connected to the second powder inlet, the outlet of the second unloading device is connected to the inlet of the second pipeline, and a second valve for controlling its opening and closing is provided at the inlet of the second pipeline.

4. The powder feeding system according to claim 3, characterized in that: The second silo is provided with an agitator, the agitator comprising a stirring shaft and a plurality of stirring parts provided on the stirring shaft, the stirring parts being columnar or blade-shaped; The first powder is blue carbon powder or coal powder, and the second powder is biomass powder.

5. The powder feeding system according to claim 1, characterized in that: A fan is included, and the outlet of the fan is communicated with the second air inlet of the second air-powder mixer.

6. The powder feeding system according to claim 1, characterized in that: The first discharge outlet is provided at the bottom of the first silo, the second discharge outlet is provided at the bottom of the second silo, the first discharge device is a discharge valve or a screw feeder, and the second discharge device is a discharge valve or a screw feeder.

7. The powder feeding system according to claim 1, characterized in that: The first air-powder mixer and the second air-powder mixer both include a feed chute having a powder inlet and a powder outlet; A mixing tube, the mixing tube comprising a third tube, a fourth tube and a fifth tube connected in sequence, the axial directions of the third tube, the fourth tube and the fifth tube being consistent, the inlet of the third tube being an air inlet, the diameter of the third tube decreasing in the axial direction of the third tube in the direction adjacent to the fourth tube, the diameter of the fourth tube being less than or equal to the diameter of the third tube and the diameter of the fifth tube, the diameter of the fifth tube increasing in the axial direction of the fifth tube in the direction away from the fourth tube, and the fourth tube being provided with an inlet connected to the powder outlet.

8. The powder feeding system according to claim 1, characterized in that: Also includes a first cover and a first feeding device, wherein the first feeding device can transport the first powder into the first silo, and the first feeding device, the first silo, the first discharge device and the first air-powder mixer are all located in the first cover; The second cover body and the second feeding device are capable of conveying the second powder into the second silo. The second feeding device, the second silo, the second unloading device and the second air-powder mixer are all located in the second cover body.

9. A boiler, characterized in that: include: A boiler body, the boiler body including a furnace; a burner, wherein an outlet of the burner is in communication with the furnace; A powder feeding system, wherein the powder feeding system is the powder feeding system according to any one of claims 1 to 8, and the powder feeding system comprises a discharge pipe, wherein the outlet of the discharge pipe is connected to the inlet of the burner.

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