Combustion device

Abstract

The combustion device comprises a screening part, a first combustor, a heat exchanger and a second combustor, a fuel mixture is contained in the screening part, the screening part is used for screening the fuel mixture into coarse fuel with the large particle size and fine fuel with the small particle size, the first combustor communicates with the screening part, and the heat exchanger communicates with the second combustor. Fine fuel screened out by the screening part can enter the first combustor, the fine fuel is combusted in the first combustor and generates heat, the heat exchanger communicates with the first combustor, the second combustor communicates with the screening part and the heat exchanger, and coarse fuel screened out by the screening part can enter the second combustor to be combusted. And heat in the first combustor enters the second combustor after being subjected to heat exchange in the heat exchanger and is used for supporting combustion of coarse particles. The combustion device is high in combustion efficiency, saves resources and reduces energy waste.

Description

Technical Field

[0001] The present invention relates to the technical field of combustion, in particular to a combustion device. Background Art

[0002] Combustion equipment typically has certain requirements for fuel particle size. Some combustion equipment, such as chain furnaces and fluidized beds, are more effective at burning large granular particles, while others, such as pulverized coal boilers, are more effective at burning small powdered particles. In related technologies, fuel is processed before combustion to select the appropriate portion of fuel for combustion, while the remaining fuel is reprocessed or discarded. However, reprocessing increases fuel processing costs, while discarding unsuitable fuel particles wastes energy and increases social waste. 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, an embodiment of the present invention provides a combustion device.

[0004] The combustion device according to the embodiment of the present invention comprises:

[0005] a screening element, wherein the screening element has a fuel mixture therein and is used to screen the fuel mixture into coarse fuel with a larger particle size and fine fuel with a smaller particle size;

[0006] a first burner, the first burner being in communication with the screening element, the fine fuel screened by the screening element being able to enter the first burner, the fine fuel being burned in the first burner to generate flue gas;

[0007] a heat exchanger, the heat exchanger being in communication with the first burner;

[0008] The second burner is connected to the screening element and the heat exchanger. The coarse fuel screened by the screening element can enter the second burner for combustion. The flue gas in the first burner can enter the heat exchanger and perform heat exchange with the outside air in the heat exchanger. The flue gas and the outside air after heat exchange can enter the second burner.

[0009] The combustion device of the embodiment of the present invention divides the fuel into coarse fuel and fine fuel through a screening element, and transports the fine fuel to the first burner and the coarse fuel to the second burner, so that both the coarse fuel and the fine fuel can be burned, saving resources. The high-temperature flue gas generated by the combustion of the fine fuel in the first burner can be heat-exchanged with the outside air in the heat exchanger to preheat the outside air. The preheated outside air and flue gas can enter the second burner to provide a good environment for the ignition and maintenance of combustion of the coarse fuel, thereby improving the combustion efficiency of the coarse fuel. Therefore, the combustion device of the embodiment of the present invention has high combustion efficiency, saves resources, and reduces energy waste.

[0010] In some embodiments, the second burner includes a rotating cone and a combustion cone, the rotating cone is spaced apart from and connected to the combustion cone, the rotating cone is rotatable relative to the combustion cone, the rotating cone is connected to the screening element, and the crude fuel can enter the rotating cone for combustion.

[0011] A driving shaft is provided in the rotating cone. The driving shaft can rotate along with the rotating shaft and can stir the coarse fuel in the rotating cone.

[0012] In some embodiments, the rotating cone has a first combustion chamber, the first combustion chamber is connected to the screening element, and the inner wall surface of the first combustion chamber is provided with a protrusion, and the protrusion can crush the fuel in the first combustion chamber.

[0013] In some embodiments, there are multiple protrusions, and the multiple protrusions are divided into at least two groups. At least two groups of protrusions are arranged at intervals along the extension direction of the push shaft in the first combustion chamber. Each group includes at least two protrusions, and at least two protrusions in each group are arranged at intervals along the circumferential inner wall surface of the first combustion chamber.

[0014] In some embodiments, the protrusion includes a protrusion and a burr, one end of the protrusion is connected to the inner wall surface of the first combustion chamber, the other end of the protrusion extends toward the center of the first combustion chamber and presents an arc surface protruding toward the center of the first combustion chamber, and the burr is arranged on the arc surface.

[0015] In some embodiments, the rotating cone has a primary air inlet connected to the first combustion chamber, the combustion cone has a second combustion chamber and a secondary air inlet connected to the second combustion chamber, the primary air inlet and the secondary air inlet are both connected to the heat exchanger, the outside air enters the primary air inlet after heat exchange with the flue gas in the heat exchanger and heats up, and the flue gas in the heat exchanger enters the secondary air inlet after cooling down.

[0016] In some embodiments, the second burner further has a discharge port, which is connected to the screening element. Unburned fuel in the second burner can enter the screening element through the discharge port for further screening.

[0017] In some embodiments, the first burner has an ignition chamber, a burnout chamber, and a mixing chamber that are sequentially connected, the ignition chamber is connected to the filter element, and the mixing chamber is connected to the heat exchanger.

[0018] The ignition chamber has a first air inlet at one end away from the burnout chamber, and the first air inlet is connected to the ignition chamber. The flow direction of the wind entering the ignition chamber through the first air inlet is opposite to the flow direction of the fine fuel in the ignition chamber. The burnout chamber has a second air inlet at one end adjacent to the ignition chamber, and the second air inlet is connected to the burnout chamber. The first burner has a plurality of third air inlets, and the plurality of third air inlets are distributed in a spiral shape along the outer circumferential surface of the first burner and are connected to the mixing chamber.

[0019] In some embodiments, the cross-sectional area of ​​the ignition chamber gradually increases along the first direction from one end of the ignition chamber away from the burnout chamber to one end of the ignition chamber adjacent to the burnout chamber, the end of the burnout chamber adjacent to the ignition chamber is arranged around the periphery of the end of the ignition chamber adjacent to the burnout chamber, the second air inlet is formed between the ignition chamber and the burnout chamber, and the cross-sectional area of ​​the burnout chamber gradually decreases along the first direction from one end of the burnout chamber adjacent to the ignition chamber to one end of the burnout chamber adjacent to the mixing chamber.

[0020] In some embodiments, the first burner further comprises:

[0021] a reverse spray member, at least a portion of which is disposed in the ignition chamber and extends along a first direction, the reverse spray member being in communication with the screening member, and the fine fuel in the screening member entering the ignition chamber through the reverse spray member;

[0022] A ventilation pipe is distributed in a spiral shape along the outer circumference of the first burner and is connected to the plurality of third air inlets. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of a combustion device according to an embodiment of the present invention.

[0024] Figure 2 yes Figure 1 Enlarged schematic diagram of part A.

[0025] Figure 3 yes Figure 1 Schematic diagram of the enlarged portion B.

[0026] Figure 4 Schematic diagram of the protruding part of the combustion device according to the embodiment of the present invention.

[0027] Figure markings: 1. screening element; 2. first burner; 21. ignition chamber; 211. first air inlet; 22. burnout chamber; 221. second air inlet; 23. mixing chamber; 231. third air inlet; 24. reverse spray element; 25. ventilation pipe; 26. return cap; 3. heat exchanger; 4. second burner; 41. rotating cone; 411. first combustion chamber; 412. primary air inlet; 42. combustion cone; 421. second combustion chamber; 422. secondary air inlet; 43. feed port; 44. discharge element; 441. rotating rod; 442. blade; 45. pushing shaft; 451. shaft body; 452. stirring blade; 46. protrusion; 461. protrusion column; 462. protrusion; 47. discharge port; 5. flow guide. DETAILED DESCRIPTION

[0028] 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.

[0029] like Figure 1-Figure 4 As shown, the combustion device of the embodiment of the present invention includes a screening element 1, a first burner 2, a heat exchanger 3 and a second burner 4. The screening element 1 contains a fuel mixture, and the screening element 1 is used to screen the fuel mixture into coarse fuel with a larger particle size and fine fuel with a smaller particle size. The first burner 2 is connected to the screening element 1, and the fine fuel screened by the screening element 1 can enter the first burner 2, and the fine fuel burns in the first burner 2 and produces flue gas. The heat exchanger 3 is connected to the first burner 2. The second burner 4 is connected to the screening element 1 and the heat exchanger 3, and the coarse fuel screened by the screening element 1 can enter the second burner 4 for combustion, and the flue gas in the first burner 2 can enter the heat exchanger 3 and perform heat exchange with the outside air in the heat exchanger 3, and the flue gas and the outside air after heat exchange can enter the second burner 4.

[0030] The combustion device of the embodiment of the present invention divides the fuel into coarse fuel and fine fuel through the screening element 1, and transports the fine fuel to the first burner 2 and the coarse fuel to the second burner 4, so that both the coarse fuel and the fine fuel can be burned, saving resources. The high-temperature flue gas generated by the combustion of the fine fuel in the first burner 2 can be heat-exchanged with the outside air in the heat exchanger 3 to preheat the outside air. The preheated outside air and flue gas can enter the second burner 4 to provide a good environment for the ignition and maintenance of combustion of the coarse fuel, thereby improving the combustion efficiency of the coarse fuel. Therefore, the combustion device of the embodiment of the present invention has high combustion efficiency and saves resources.

[0031] Specifically, fine fuel refers to fuel with a particle size of no more than 1mm to 4mm, while coarse fuel refers to fuel with a particle size greater than 4mm. For fuels with lower calorific value, smaller particles are more likely to burn and release heat under the same conditions. Therefore, the fine fuel with smaller particles enters the first burner 2 for combustion first. The heat generated after combustion provides thermal support for the combustion of the coarse fuel. The first burner 2 is insulated and does not easily exchange heat with the outside world, thus providing a higher combustion temperature for the fine fuel.

[0032] In some embodiments, the second burner 4 includes a rotating cone 41 and a combustion cone 42. The rotating cone 41 and the combustion cone 42 are arranged at intervals and connected. The rotating cone 41 can rotate relative to the combustion cone 42. The rotating cone 41 is connected to the screening element 1, and the coarse fuel can enter the rotating cone 41 for combustion.

[0033] Specifically, the combustion cone 42 has a feed port 43, which is connected to the combustion cone 42 and the rotating cone 41. The crude fuel can enter the rotating cone 41 through the feed port 43 for combustion.

[0034] Specifically, the second burner 4 also includes a discharge piece 44, which is arranged on the outer periphery of the rotating cone 41 and is connected to the gap between the rotating cone 41 and the combustion cone 42, so that the unburned carbon and fly ash that are sucked into the combustion cone 42 and separated from the gas can fall into the discharge piece 44 through the gap. The central axis of the rotating cone 41 is at an angle α with the horizontal, 0°≤α≤90°, and the central axis of the combustion cone 42 is at an angle β with the horizontal, 0°≤β≤90°, and the angle difference between α and β is less than 10°. The rotating cone 41 is composed of several grate structures, each of which has holes for ventilation on the rotating cone 41. There are gaps between the grates, so that particles smaller than the gaps can fall into the discharge piece 44.

[0035] In some embodiments, a driving shaft 45 is provided in the rotating cone 41 . The driving shaft 45 can rotate along with the rotating shaft. The driving shaft 45 can stir the coarse fuel in the rotating cone 41 .

[0036] Specifically, the cross-sectional area of ​​the end of the rotating cone 41 away from the combustion cone 42 is smaller than the cross-sectional area of ​​the end of the rotating cone 41 adjacent to the combustion cone 42, and the inner circumference of the rotating cone 41 is generally bowl-shaped. Because the rotating cone 41 and the combustion cone 42 are arranged at an angle, the coarse fuel within the rotating cone 41 tends to concentrate in the area away from the combustion cone 42 due to its own gravity. Furthermore, at this end of the rotating cone 41, the radius of the rotating cone 41 is small, and the linear velocity of the particles in this area is low. The combination of these two factors results in insufficient agitation of the fuel in this area, which is also the area with high combustion temperatures and is therefore most prone to agglomeration and the formation of large coke lumps. Therefore, the propulsion shaft 45 is provided within the rotating cone 41 to enhance agitation of the fuel within the rotating cone 41 and prevent the formation of large coke lumps.

[0037] Specifically, the driving shaft 45 includes a shaft body 451 and stirring blades 452 . One end of the shaft body 451 extends into the rotating shaft and extends along the axis of the rotating shaft. The stirring blades 452 are spirally arranged along the outer circumference of the shaft body 451 .

[0038] When the rotating cone 41 is operating normally, the shaft body 451 and the rotating cone 41 rotate coaxially and in the same direction in the equipment, giving the fuel at the end of the rotating cone 41 away from the combustion cone 42 an axial driving force along the center of the rotating cone 41 toward the end of the rotating cone 41 adjacent to the combustion cone 42, thereby enhancing agitation, avoiding the formation of large coke, and increasing the mixing of the high-temperature area of ​​the fuel bed and the newly introduced fuel, providing strong conditions for the smooth ignition of the newly introduced fuel.

[0039] When the rotating cone 41 stops running for maintenance, the driving shaft 45 can be rotated in the opposite direction of the same axis and removed from the end of the rotating cone 41 away from the combustion cone 42. The stirring blades 452 on the shaft body 451 can give the residual material in the rotating cone 41 a reverse axial thrust as the shaft body 451 rotates, which is conducive to the smooth discharge of the residual material.

[0040] In some embodiments, the rotating cone 41 has a first combustion chamber 411 , which is connected to the screening element 1 . The inner wall of the first combustion chamber 411 is provided with a protrusion 46 , which can crush the fuel in the first combustion chamber 411 .

[0041] Specifically, the protrusion 46 has a certain height. During the rotation of the rotating cone 41, the fuel will flip over under the blocking effect of the protrusion 46 to increase the turning and loosening process of the fuel, thereby enhancing combustion and preventing the fuel from sticking and coking.

[0042] In some embodiments, there are multiple protrusions 46, and the multiple protrusions 46 are divided into at least two groups. At least two groups of protrusions 46 are arranged at intervals along the extension direction of the push shaft 45 in the first combustion chamber 411. Each group includes at least two protrusions 46, and at least two protrusions 46 in each group are arranged at intervals along the circumferential inner wall surface of the first combustion chamber 411.

[0043] Specifically, the provision of multiple protrusions 46 can further increase the turning and loosening of the fuel, enhance the combustion of the fuel, and prevent the fuel from sticking and coking.

[0044] It can be understood that the arrangement of multiple protrusions 46 is not limited to the above-mentioned arrangement. Multiple protrusions 46 can also be arranged in a spiral line on the inner wall surface of the first combustion chamber 411 from the end of the rotating cone 41 away from the combustion cone 42 to the end of the rotating cone 41 adjacent to the combustion cone 42. The arrangement direction of the spiral line is such that as the rotating cone 41 rotates, the fuel in the rotating cone 41 can be pushed axially from the end of the rotating cone 41 away from the combustion cone 42 to the end of the rotating cone 41 adjacent to the combustion cone 42.

[0045] In some embodiments, the protrusion 46 includes a protrusion 461 and a protrusion 462. One end of the protrusion 461 is connected to the inner wall surface of the first combustion chamber 411, and the other end of the protrusion 461 extends toward the center of the first combustion chamber 411 and presents an arc surface protruding toward the center of the first combustion chamber 411. The protrusion 462 is arranged on the arc surface.

[0046] Specifically, the thorns 462 can crush larger fuel and agglomerated coke that collide with or touch the protrusion 46. Compared with the coke crushing equipment such as the crushing ball added to the rotating cone 41 in the prior art that can move with the fuel, it will be driven and fall with the rotation of the rotating cone 41, and its own weight will cause a certain impact on the structure of the rotating cone 41. The protrusion 46 proposed in the present invention is installed on the equipment body and can rotate with the rotating cone 41. It has no additional impact force on the equipment itself, which is conducive to the long-term operation of the equipment.

[0047] Specifically, the number of thorns 462 provided on the arc surface is 1 to 5, and they are symmetrically arranged along the central axis of the convex column 461. The thorns 462 are avoided from being distributed in the lower half to prevent the thorns 462 from causing fuel jamming between the grates of the rotating cone 41.

[0048] In some embodiments, the rotating cone 41 has a primary air inlet 412 connected to the first combustion chamber 411, the combustion cone 42 has a second combustion chamber 421 and a secondary air inlet 422 connected to the second combustion chamber 421, the primary air inlet 412 and the secondary air inlet 422 are both connected to the heat exchanger 3, the outside air enters the primary air inlet 412 after heat exchange with the flue gas in the heat exchanger 3 and heats up, and the flue gas in the heat exchanger 3 enters the secondary air inlet 422 after cooling down.

[0049] Specifically, the primary air inlet 412 is located at one end of the rotating cone 41 away from the combustion cone 42, and primary air is introduced into the rotating cone 41 through the primary air inlet 412. The secondary air inlet 422 is located at one end of the combustion cone 42 away from the rotating cone 41, and secondary air is introduced into the combustion cone 42 through the secondary air inlet 422. The secondary air from the combustion cone 42 enters through the secondary air inlet 422 and descends into the rotating cone 41. Driven by the rotating cone 41, the flow of the primary air, and the swirling agitation of the secondary air, the fuel in the rotating cone 41 comes into contact with the combustion-supporting gas, causing it to heat up rapidly, tumble continuously, and react on multiple surfaces, thereby improving the ignition and combustion efficiency of the initial fuel.

[0050] In some embodiments, the second burner 4 further has a discharge port 47 , which is connected to the screening element 1 , and the unburned fuel in the second burner 4 can enter the screening element 1 through the discharge port 47 for further screening.

[0051] Specifically, a discharge port 47 is formed on the discharge member 44 to facilitate the discharge of the fuel in the discharge member 44. A rotating rod 441 is also provided in the discharge member 44, and a spirally arranged blade 442 is provided on the rotating rod 441. The rotating rod 441 rotates around its own extension direction to drive the blade 442 to rotate. Since the initial coarse fuel has a low calorific value, the ash particles in the rotating cone 41 often still have a certain calorific value. Moreover, after high-temperature combustion, there is a certain agglomeration effect, which increases the particle size. The ash particles fall into the discharge member 44 through the gap. The rotating rod 441 drives the blade 442 to rotate, so that the ash residue in the discharge member 44 is discharged through the discharge port 47 and returned to the front of the screening member 1. The entire process of screening and particle size-based combustion is cyclically carried out, realizing the cyclic combustion utilization of the fuel and further improving the combustion efficiency of the fuel.

[0052] In some embodiments, the first burner 2 has a ignition chamber 21, a burnout chamber 22, and a mixing chamber 23 that are sequentially connected. The ignition chamber 21 is connected to the filter element 1, and the mixing chamber 23 is connected to the heat exchanger 3. The ignition chamber 21 has a first air inlet 211 at one end away from the burnout chamber 22. The first air inlet 211 is connected to the ignition chamber 21. The flow direction of the air entering the ignition chamber 21 through the first air inlet 211 is arranged opposite to the flow direction of the fine fuel in the ignition chamber 21. The burnout chamber 22 has a second air inlet 221 at one end adjacent to the ignition chamber 21. The second air inlet 221 is connected to the burnout chamber 22. The first burner 2 has a plurality of third air inlets 231. The plurality of third air inlets 231 are distributed in a spiral shape along the outer circumference of the first burner 2 and are connected to the mixing chamber 23.

[0053] The cross-sectional area of ​​the ignition chamber 21 gradually increases along the first direction from the end of the ignition chamber 21 away from the burnout chamber 22 to the end of the ignition chamber 21 adjacent to the burnout chamber 22. The end of the burnout chamber 22 adjacent to the ignition chamber 21 is arranged around the periphery of the end of the ignition chamber 21 adjacent to the burnout chamber 22. The second air inlet 221 is formed between the ignition chamber 21 and the burnout chamber 22. The cross-sectional area of ​​the burnout chamber 22 gradually decreases along the first direction from the end of the burnout chamber 22 adjacent to the ignition chamber 21 to the end of the burnout chamber 22 adjacent to the mixing chamber 23.

[0054] Specifically, the walls of the ignition chamber 21 are insulated, preventing the heat from the initial ignition of the fine fuel from dissipating to the outside world, thus providing a better environment for initial ignition. The combustion-supporting air entering through the first air inlet 211 accounts for 0.3-0.7 of the total air volume required for fine fuel combustion. This is because the flame propagation speed of difficult-to-burn flames is slow, and a smaller proportion of the combustion-supporting air can reduce the average cross-sectional velocity of the ignition chamber 21, further providing a better environment for initial ignition.

[0055] The burnout chamber 22 provides space for the burnout of coal powder particles. The coal powder particles that arrive here have already been ignited. If they touch the wall of the burnout chamber 22, they are likely to stick to each other. Therefore, a cooling air guide 5 is set at the connection between the wall of the burnout chamber 22 and the wall of the ignition chamber 21, so that the cooling air can pass through the guide 5 and enter the burnout chamber 22 at the same angle as the wall of the burnout chamber 22 after entering, forming a cooling protective film on the wall of the burnout chamber 22. The burnout air entering through the second air inlet 221 accounts for 0.3 to 0.7 of the total air required for the combustion of fine fuel. The burnout chamber 22 is cone-shaped with a large front end and a small rear end. The flue gas is gradually accelerated by the cone and then enters the mixing chamber 23.

[0056] When the mixed air enters the mixing chamber 23 through the third air inlet 231, its speed is increased to more than 50m / s and is quickly mixed with the high-temperature flue gas in the mixing chamber 23 at a certain angle, further reducing the temperature of the flue gas. The angle at which the mixed air and the high-temperature flue gas in the third air inlet 231 meet is 30° to 180°, and 90° is commonly taken. In addition, the higher speed of the gas in the third air inlet 231 also prevents the dust-laden flue gas in the mixing chamber 23 from overflowing from the third air inlet 231.

[0057] In some embodiments, the first burner 2 further includes a reverse spray member 24 and a ventilation pipe 25. At least a portion of the reverse spray member 24 is disposed within the ignition chamber 21 and extends along the first direction. The reverse spray member 24 is in communication with the filter member 1, and fine fuel within the filter member 1 enters the ignition chamber 21 through the reverse spray member 24. The ventilation pipe 25 is distributed in a spiral shape along the outer circumference of the first burner 2 and is in communication with the plurality of third air inlets 231.

[0058] Specifically, a reflux cap 26 is provided at one end of the reverse spray member 24 extending into the ignition chamber 21 so that the fine fuel in the reverse spray member 24 can flow in the opposite direction to the combustion-supporting air in the ignition chamber 21, so that the fine fuel can be fully burned and the combustion efficiency is improved.

[0059] The principle of the combustion device of the embodiment of the present invention is:

[0060] The mixed fuel is screened by the screening element 1 into coarse fuel and fine fuel. The fine fuel is delivered to the first burner 2, and the coarse fuel is delivered to the second burner 4. When the fine fuel burns in the first burner 2, it is ventilated into the ignition chamber 21 through the first air inlet 211. The fine fuel burns in the ignition chamber 21 and produces high-temperature flue gas with a temperature of 900°C to 1200°C. The fine fuel is ventilated into the burnout chamber 22 through the second air inlet 221 to prevent fuel particles from adhering to the inner wall of the burnout chamber 22. The third air inlet 231 is used to ventilate the mixing chamber 23, which can cool the mixing chamber 23 to keep the flue gas temperature below the ash melting point. At this time, the temperature of the high-temperature flue gas is generally 500℃~900℃, and then the high-temperature flue gas enters the heat exchanger 3. The high-temperature flue gas exchanges heat with the wind entering the heat exchanger 3 in the heat exchanger 3, so that the wind entering the heat exchanger 3 is heated to 100℃~300℃. The wind after heat exchange enters the primary air inlet 412 to help the crude fuel in the rotating cone 41 to burn. After the high-temperature flue gas exchanges heat with the wind entering the heat exchanger 3 in the heat exchanger 3, the temperature is reduced and enters the secondary air inlet 422.

[0061] In the combustion device of the embodiment of the present invention, the fine fuel is burned in an insulated environment and a reverse injection structure, with high combustion efficiency. The heat from the combustion of the fine fuel provides heat for the coarse fuel, which can improve the combustion efficiency of the difficult-to-burn fuel. The primary air of the rotating cone 41 is preheated by the high-temperature flue gas of the first burner 2, providing heat for the ignition of the difficult-to-burn coarse fuel. The high-temperature flue gas from the combustion of the fine fuel serves as secondary air for the combustion of the coarse fuel, further increasing the combustion efficiency of the difficult-to-burn fuel in the combustion cone 42. The fuel that falls from the second burner 4 into the discharge part 44 circulates into the fuel screening link of the device, realizing fuel recycling and further improving the combustion efficiency of the difficult-to-burn fuel. The combustion efficiency can eventually reach 99%.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", 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 expressions 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 one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0067] 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 combustion device, characterized in that: include: A screening element (1), wherein the screening element (1) contains a fuel mixture, and the screening element (1) is used to screen the fuel mixture into coarse fuel with a larger particle size and fine fuel with a smaller particle size; a first burner (2), the first burner (2) being in communication with the screening element (1), the fine fuel screened by the screening element (1) being able to enter the first burner (2), the fine fuel being burned in the first burner (2) and generating smoke; a heat exchanger (3), the heat exchanger (3) being in communication with the first burner (2); The second burner (4) is connected to the screening element (1) and the heat exchanger (3); the coarse fuel screened by the screening element (1) can enter the second burner (4) for combustion; the flue gas in the first burner (2) can enter the heat exchanger (3) and perform heat exchange with the external air in the heat exchanger (3); and the flue gas and the external air after the heat exchange can enter the second burner (4).

2. The combustion device according to claim 1, characterized in that The second burner (4) includes a rotating cone (41) and a combustion cone (42). The rotating cone (41) and the combustion cone (42) are spaced apart and connected. The rotating cone (41) is rotatable relative to the combustion cone (42). The rotating cone (41) is connected to the screening element (1). Coarse fuel can enter the rotating cone (41) for combustion. A driving shaft (45) is provided in the rotating cone (41), and the driving shaft (45) can rotate along with the rotating shaft. The driving shaft (45) can stir the coarse fuel in the rotating cone (41).

3. The combustion device according to claim 2, characterized in that The rotating cone (41) has a first combustion chamber (411), the first combustion chamber (411) is connected to the screening element (1), and a protrusion (46) is provided on the inner wall surface of the first combustion chamber (411), and the protrusion (46) can crush the fuel in the first combustion chamber (411).

4. The combustion device according to claim 3, characterized in that There are multiple protrusions (46), and the multiple protrusions (46) are divided into at least two groups. At least two groups of protrusions (46) are arranged at intervals along the extension direction of the driving shaft (45) in the first combustion chamber (411), and each group includes at least two protrusions (46). At least two protrusions (46) in each group are arranged at intervals along the circumferential inner wall of the first combustion chamber (411).

5. The combustion device according to claim 3, characterized in that: The convex part (46) includes a convex column (461) and a convex thorn (462), one end of the convex column (461) is connected to the inner wall surface of the first combustion chamber (411), the other end of the convex column (461) extends toward the center of the first combustion chamber (411) and presents an arc surface convex toward the center of the first combustion chamber (411), and the convex thorn (462) is provided on the arc surface.

6. The combustion device according to claim 2, characterized in that: The rotating cone (41) has a primary air inlet (412) connected to the first combustion chamber (411), and the combustion cone (42) has a second combustion chamber (421) and a secondary air inlet (422) connected to the second combustion chamber (421). The primary air inlet (412) and the secondary air inlet (422) are both connected to the heat exchanger (3). External air enters the primary air inlet (412) after being heated by heat exchange with the flue gas in the heat exchanger (3), and the flue gas in the heat exchanger (3) enters the secondary air inlet (422) after being cooled.

7. The combustion device according to claim 1, characterized in that The second burner (4) further has a discharge port (47), which is in communication with the screening element (1), and unburned fuel in the second burner (4) can enter the screening element (1) through the discharge port (47) to be screened again.

8. The combustion device according to claim 1, characterized in that The first burner (2) has an ignition chamber (21), a burnout chamber (22), and a mixing chamber (23) which are connected in sequence. The ignition chamber (21) is connected to the screening element (1), and the mixing chamber (23) is connected to the heat exchanger (3). The ignition chamber (21) has a first air inlet (211) at one end away from the burnout chamber (22), the first air inlet (211) is connected to the ignition chamber (21), and the flow direction of the wind entering the ignition chamber (21) through the first air inlet (211) is arranged opposite to the flow direction of the fine fuel in the ignition chamber (21). The burnout chamber (22) has a second air inlet (221) at one end adjacent to the ignition chamber (21), the second air inlet (221) is connected to the burnout chamber (22), and the first burner (2) has a plurality of third air inlets (231), the plurality of third air inlets (231) are distributed in a spiral shape along the outer peripheral surface of the first burner (2) and are connected to the mixing chamber (23).

9. The combustion device according to claim 8, characterized in that: The cross-sectional area of ​​the ignition chamber (21) gradually increases along the first direction from one end of the ignition chamber (21) away from the burnout chamber (22) to one end of the ignition chamber (21) adjacent to the burnout chamber (22); the end of the burnout chamber (22) adjacent to the ignition chamber (21) is arranged around the periphery of one end of the ignition chamber (21) adjacent to the burnout chamber (22); the second air inlet (221) is formed between the ignition chamber (21) and the burnout chamber (22); the cross-sectional area of ​​the burnout chamber (22) gradually decreases along the first direction from one end of the burnout chamber (22) adjacent to the ignition chamber (21) to one end of the burnout chamber (22) adjacent to the mixing chamber (23).

10. The combustion device according to claim 8, characterized in that: The first burner (2) further comprises: a reverse spray member (24), at least a portion of which is disposed in the ignition chamber (21) and extends along a first direction, the reverse spray member (24) being in communication with the screening member (1), and the fine fuel in the screening member (1) entering the ignition chamber (21) through the reverse spray member (24); A ventilation pipe (25) is distributed in a spiral shape along the outer peripheral surface of the first burner (2) and is connected to the plurality of third air inlets (231).

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