A multi-stage preheating dual-mode low NOx self-preheating burner

Abstract

The present invention relates to a multi-stage preheating dual-mode low NOx self-preheating burner, which belongs to the technical field of industrial burners and is mainly used in industrial furnaces in the steel, nonferrous metals, machinery, aviation, forging, ceramics and other industries. In the present invention, the burner housing is installed at one end of a smoke guide device, the tile is installed at the other end of the smoke guide device, the burner core is installed on the tile, the air smoke guide is installed in the burner housing, and the air smoke guide is matched with the smoke guide device, one end of the heat exchanger is installed on the air smoke guide, and the other end of the heat exchanger is connected to the tile, one end of the air guide tube is installed on the burner housing, and the other end of the air guide tube is located in the heat exchanger, the burner end cover and one end of the air tube are both installed on the burner housing, the smoke exhaust pipe is installed in the air tube, and the smoke exhaust pipe is connected to the air smoke guide.

Description

Technical Field

[0001] The invention relates to a multi-stage preheating dual-mode low NOx self-preheating burner, which belongs to the technical field of industrial burners and is mainly used for industrial furnaces in industries such as steel, nonferrous metals, machinery, aviation, forging, and ceramics. Background Art

[0002] At present, most of the self-preheating burners have flue gas flowing in the outermost cavity of the burner shell, which has the disadvantages of high burner shell temperature, large resistance, relatively low heat exchange efficiency, and low burner power. At the same time, the burner classification effect is not good, the flame is short, the temperature is low, the NOx emission is high, and the burner outlet structure has poor high temperature resistance. In addition, the flameless mode gas pipe extends to the burner nozzle, which is easy to burn out and has a short service life, such as invention patent 201811304912.2, which affects its promotion and application in high-temperature and high-performance large-scale industrial furnaces. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a multi-stage preheating dual-mode low NOx self-preheating burner with a reasonable structural design.

[0004] The technical solution adopted by the present invention to solve the above-mentioned problem is: the multi-stage preheating dual-mode low NOx self-preheating burner includes a burner shell, an air and smoke deflector, a heat exchanger, an air deflector tube, a smoke deflector device, a burner end cover, a burner core, a tile, an air tube and a smoke exhaust pipe, and its structural characteristics are: the burner shell is installed at one end of the smoke deflector device, the tile is installed at the other end of the smoke deflector device, the burner core is installed on the tile, the air and smoke deflector is installed in the burner shell, and the air and smoke deflector cooperates with the smoke deflector device, one end of the heat exchanger is installed on the air and smoke deflector, and the other end of the heat exchanger is connected to the inlet end of the tile, one end of the air deflector tube is installed on the burner shell, and the other end of the air deflector tube is located in the heat exchanger, the burner end cover and one end of the air tube are both installed on the burner shell, the smoke exhaust pipe is installed in the air tube, and the smoke exhaust pipe is connected to the air and smoke deflector.

[0005] Furthermore, the burner core is connected to the inlet end of the tile, the heat exchanger is installed in the air and smoke deflector, and the air deflector tube is installed in the heat exchanger.

[0006] Furthermore, an air final preheating channel is formed between the outer wall of the air guide tube and the inner wall of the heat exchanger.

[0007] Furthermore, an air smoke deflector outer cavity is provided outside the air smoke deflector, an air smoke deflector inner cavity is provided inside the air smoke deflector, the air smoke deflector outer cavity is connected with the air smoke deflector inner cavity, a burner shell inner cavity is provided inside the burner shell, an air cylinder inner cavity is provided between the outer wall of the smoke exhaust pipe and the inner wall of the air cylinder, the air cylinder inner cavity is connected with the burner shell inner cavity, and one end of the smoke exhaust pipe is connected with the air smoke deflector outer cavity.

[0008] Furthermore, the outer cavity of the air and smoke deflector is a secondary smoke heat exchange channel, and an air secondary preheating channel is formed between the outer wall of the air and smoke deflector and the inner wall of the burner shell.

[0009] Furthermore, the other end of the smoke exhaust pipe is a smoke outlet, the interior of the smoke exhaust pipe is a smoke outlet channel, the outer wall of the smoke exhaust pipe is equipped with smoke exhaust pipe fins, the smoke exhaust pipe fins are located in the inner cavity of the air cylinder, and the air cylinder is provided with an air inlet, which is connected to the inner cavity of the air cylinder.

[0010] Furthermore, the smoke exhaust pipe fins are arranged in a spiral structure, and the smoke exhaust pipe fins divide the inner cavity of the air cylinder into primary air preheating channels.

[0011] Furthermore, the shell of the flue gas guide device is made of metal material, and refractory material is arranged inside the shell; or the shell of the flue gas guide device is made of heat-resistant alloy material, and the shell is connected to the burner shell through a flange.

[0012] Furthermore, a smoke guide cavity is provided in the smoke guide device, and the smoke guide cavity is connected with the inner cavity of the air smoke guide device. The other end of the heat exchanger is located in the smoke guide cavity. The burner core and the tile are both located in the smoke guide cavity and cooperate with the other end of the heat exchanger.

[0013] Furthermore, the outer wall of the air guide tube is provided with air guide tube fins; the air guide tube fins are arranged in a circular array; or the air guide tube fins are arranged in a spiral shape; or the air guide tube fins are arranged in a combination of a circular array and a spiral shape; or the air guide tube fins are arranged in a stepped shape. When the air guide tube fins are arranged in a stepped shape, a sieve-like structure is provided between the air guide tube fins and the horizontal part of the air guide tube.

[0014] Furthermore, the heat exchanger is arranged in a cylindrical structure, the outer wall of the heat exchanger is provided with heat exchanger fins, and the other end of the heat exchanger is installed with a ring sleeve, and the ring sleeve is in contact with the tile.

[0015] Furthermore, a primary smoke heat exchange channel is formed between the outer wall of the heat exchanger and the inner cavity of the air and smoke deflector and the smoke deflection cavity.

[0016] Furthermore, a baffle is installed at one end of the burner core, and a refractory material protective layer is provided at the other end of the burner core, and the end cooperates with the tile, a boss is installed on the baffle, a center hole is provided on the boss, and a plurality of primary air holes are provided circumferentially of the boss, and the plurality of primary air holes are all provided on the baffle, the number of the primary air holes is m, and the value range of m is 4-12, one end of the primary air hole is connected to the inner cavity of the heat exchanger, and the other end of the primary air hole is connected to the combustion chamber, a plurality of diverter plates are provided on the outer wall of the burner core, and the plurality of diverter plates are arranged in a circular array along the axis of the burner core, and there is a secondary air duct between two adjacent diverter plates, the number of the secondary air ducts is n, and the value range of n is 3-24, one end of the secondary air duct is connected to the inner cavity of the heat exchanger, and the other end of the secondary air duct is connected to the combustion chamber.

[0017] Furthermore, a combustion chamber is provided on the tile, and the combustion chamber is arranged in a trumpet-shaped structure. A plurality of air channels are arranged in the circumference of the combustion chamber, and the number of the air channels is x, and the value range of x is 4-16. The air channels are arranged at an angle, and the angle between the axis of the air channel and the axis of the combustion chamber is α, and the value range of α is 0-20°. A plurality of smoke channels are arranged on the outer wall of the tile, and the smoke channels are arranged in a fan-shaped structure. The number of the smoke channels is y, and the value range of y is 4-12.

[0018] Furthermore, two ends of the combustion chamber are respectively a combustion chamber outlet and a combustion chamber inlet.

[0019] Furthermore, a first-level gas pipe is provided on the burner end cover, a second-level gas pipe is installed in the first-level gas pipe, one end of the first-level gas pipe is communicated with the gas interface on the gas end cover, one end of the second-level gas pipe is exposed at the burner end cover, the other end of the first-level gas pipe is connected to the burner core, the other end of the second-level gas pipe penetrates the burner core and is located in the tile, an ignition device is installed on the burner end cover, one end of the ignition device is exposed at the burner end cover, the other end of the ignition device is connected to the burner core, and a flame monitoring device is installed on the burner end cover.

[0020] Furthermore, the primary gas pipe and the ignition device are both located in the air guide tube, and a flame monitoring device is installed on the burner end cover.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The air cylinder is mounted outside the exhaust pipe. The air after primary heat exchange is outside the exhaust pipe, and the high-temperature flue gas is inside the exhaust pipe. Therefore, the outer wall temperature of the air cylinder is low, and the air passes through the spiral channel, and the heat exchange path is lengthened. After primary preheating, the air enters the burner shell and the air and flue gas deflector for secondary heat exchange, and finally enters the heat exchanger and the air and flue gas deflector for final heat exchange (three stages), which greatly improves the heat exchange path, heat exchange area and heat exchange efficiency, increases the air preheating temperature, increases the combustion efficiency, and improves the thermal efficiency and energy utilization rate.

[0023] 2. During the primary and secondary preheating of the air, the air circulation channel is outside the air and smoke deflector, and the smoke circulation channel is inside the air and smoke deflector, which reduces the smoke circulation resistance and makes the smoke exhaust smoother. At the same time, it also greatly reduces the temperature of the outer wall of the burner, increases the service life of the burner, improves the working environment of the burner, and makes the burner more user-friendly.

[0024] 3. Fins are arranged on the outer wall of the air guide tube, and a variety of structural forms (circumferential array, spiral, combination of spiral and circular array, and stepped) are adopted. They can be flexibly selected according to different working conditions and occasions to achieve the best heat exchange efficiency and performance of the burner.

[0025] 4. The preheated air can be injected into the combustion chamber through the burner core for the first and second times to mix with the first-stage gas, and the tertiary air can be injected directly into the heating space through the air channel to mix with the mixed air and gas ejected from the combustion chamber to achieve multi-stage mixing and minimize NOx generation. The preheated air and the second-stage gas can also be injected into the heating space to form diffusion combustion, resulting in ultra-low NOx generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic cross-sectional structure diagram of a multi-stage preheating dual-mode low NOx self-preheating burner in which the flue gas guide device of an embodiment of the present invention is made of a metal shell with built-in refractory material and the air guide tube fins are arranged in a circular array.

[0027] Figure 2 It is a schematic cross-sectional structure diagram of a multi-stage preheating dual-mode low NOx self-preheating burner in which the flue gas guide device of an embodiment of the present invention is made of a metal shell with built-in refractory material and the air guide tube fins are arranged in a stepped manner.

[0028] Figure 3 It is a schematic cross-sectional structure diagram of a multi-stage preheating dual-mode low NOx self-preheating burner in which the flue gas guide device of an embodiment of the present invention is made of a metal shell with built-in refractory material and the air guide tube fins are arranged in a circular array and spiral combination.

[0029] Figure 4It is a left-side structural schematic diagram of a multi-stage preheating dual-mode low NOx self-preheating burner when the flue gas guide device of an embodiment of the present invention is made of a metal shell with built-in refractory material.

[0030] Figure 5 It is a right view structural schematic diagram of a multi-stage preheating dual-mode low NOx self-preheating burner when the flue gas guide device of an embodiment of the present invention is made of a metal shell with built-in refractory material.

[0031] Figure 6 It is a schematic cross-sectional structure diagram of a multi-stage preheating dual-mode low NOx self-preheating burner when the shell of the flue gas guide device of an embodiment of the present invention is made of a heat-resistant alloy material and the air guide tube fins are arranged in a circular array.

[0032] Figure 7 It is a schematic cross-sectional structure diagram of a multi-stage preheating dual-mode low NOx self-preheating burner when the shell of the flue gas guide device in an embodiment of the present invention is made of a heat-resistant alloy material and the air guide tube fins are arranged in a stepped manner.

[0033] Figure 8 It is a schematic cross-sectional structure diagram of a multi-stage preheating dual-mode low NOx self-preheating burner in which the shell of the flue gas guide device of an embodiment of the present invention is made of a heat-resistant alloy material and the air guide tube fins are arranged in a circular array and spiral combination.

[0034] Fig. 9 It is a right view structural schematic diagram of a multi-stage preheating dual-mode low NOx self-preheating burner when the shell of the flue gas guide device in an embodiment of the present invention is made of a heat-resistant alloy material.

[0035] Fig.10 It is a schematic diagram of the three-dimensional structure of the tile according to an embodiment of the present invention.

[0036] Fig.11 It is a schematic diagram of the three-dimensional structure of the tile according to an embodiment of the present invention.

[0037] Fig.12 It is a schematic diagram of the three-dimensional structure of the burner core according to an embodiment of the present invention.

[0038] Fig.13 It is a schematic diagram of the three-dimensional structure of the burner core according to an embodiment of the present invention.

[0039] In the figure: burner shell 1, air and smoke deflector 2, heat exchanger 3, air deflector tube 4, smoke deflector device 5, burner end cover 6, burner core 7, tile 8, air tube 9, smoke exhaust pipe 10,

[0040] Burner shell cavity 11,

[0041] The air and smoke deflector outer cavity 21, the air and smoke deflector inner cavity 22,

[0042] Heat exchanger fin 31, ring sleeve 32,

[0043] Air guide tube fin 41,

[0044] Smoke guide cavity 51,

[0045] Gas interface 60, primary gas pipe 61, secondary gas pipe 62, ignition device 63, flame monitoring device 64,

[0046] Center hole 70, primary air hole 71, secondary air duct 72, boss 73, flow divider 74, baffle 75, refractory protective layer 76,

[0047] Combustion chamber 80, air channel 81, smoke channel 82, combustion chamber outlet 801, combustion chamber inlet 802,

[0048] Air inlet 90, air cylinder inner cavity 91,

[0049] Smoke exhaust pipe fins 101 , smoke outlet channel 102 , and smoke outlet 103 . DETAILED DESCRIPTION

[0050] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0051] Example

[0052] See also Figures 1 to 13 As shown, it should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, if there are references to terms such as "upper", "lower", "left", "right", "middle" and "one" in this specification, they are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0053] The multi-stage preheating dual-mode low NOx self-preheating burner in this embodiment includes a burner shell 1, an air and smoke deflector 2, a heat exchanger 3, an air deflector tube 4, a smoke deflector device 5, a burner end cover 6, a burner core 7, a tile 8, an air tube 9 and a smoke exhaust pipe 10. The heat exchanger 3 is installed in the air and smoke deflector 2, and the air deflector tube 4 is installed in the heat exchanger 3; an air final preheating channel is formed between the outer wall of the air deflector tube 4 and the inner wall of the heat exchanger 3.

[0054] The burner housing 1 in this embodiment is installed at one end of the smoke guide device 5, the tile 8 is installed at the other end of the smoke guide device 5, the burner core 7 is connected to the inlet end of the tile 8, and the outlet end of the tile 8 is the heated space. The air and smoke deflector 2 is installed in the burner housing 1, and the air and smoke deflector 2 cooperates with the smoke guide device 5. One end of the heat exchanger 3 is installed on the air and smoke deflector 2, and the other end of the heat exchanger 3 is connected to the inlet end of the tile 8. One end of the air guide tube 4 is installed on the burner housing 1, and the other end of the air guide tube 4 is located in the heat exchanger 3. One end of the burner end cover 6 and the air tube 9 are both installed on the burner housing 1. The exhaust pipe 10 is installed in the air tube 9, and the exhaust pipe 10 is connected to the air and smoke deflector 2.

[0055] In this embodiment, an air smoke deflector outer cavity 21 is arranged outside the air smoke deflector 2, an air smoke deflector inner cavity 22 is arranged inside the air smoke deflector 2, the air smoke deflector outer cavity 21 is connected with the air smoke deflector inner cavity 22, a burner shell inner cavity 11 is arranged inside the burner shell 1, an air cylinder inner cavity 91 is arranged between the outer wall of the smoke exhaust pipe 10 and the inner wall of the air cylinder 9, the air cylinder inner cavity 91 is connected with the burner shell inner cavity 11, and one end of the smoke exhaust pipe 10 is connected with the air smoke deflector outer cavity 21; the air smoke deflector outer cavity 21 is a secondary smoke heat exchange channel, and an air secondary preheating channel is formed between the outer wall of the air smoke deflector 2 and the inner wall of the burner shell 1.

[0056] The other end of the smoke exhaust pipe 10 in this embodiment is a smoke outlet 103, and the interior of the smoke exhaust pipe 10 is a smoke outlet channel 102. The outer wall of the smoke exhaust pipe 10 is installed with a smoke exhaust pipe fin 101, and the smoke exhaust pipe fin 101 is located in the air cylinder inner cavity 91. The air cylinder 9 is provided with an air inlet 90, and the air inlet 90 is connected to the air cylinder inner cavity 91; the smoke exhaust pipe fin 101 is arranged in a spiral structure, and the smoke exhaust pipe fin 101 divides the air cylinder inner cavity 91 into an air primary preheating channel.

[0057] The shell of the smoke guide device 5 in this embodiment is made of metal material, and refractory material is arranged inside the shell; or the shell of the smoke guide device 5 is made of heat-resistant alloy material, and the shell is connected to the burner shell 1 through a flange; a smoke guide cavity 51 is arranged inside the smoke guide device 5, and the smoke guide cavity 51 is connected to the air smoke guide cavity 22, the other end of the heat exchanger 3 is located in the smoke guide cavity 51, and the burner core 7 and the tile 8 are both located in the smoke guide cavity 51 and are matched with the other end of the heat exchanger 3.

[0058] The outer wall of the air guide tube 4 in this embodiment is provided with air guide tube fins 41; the air guide tube fins 41 are arranged in a circular array; or the air guide tube fins 41 are arranged in a spiral shape; or the air guide tube fins 41 are arranged in a combination of a circular array and a spiral shape; or the air guide tube fins 41 are arranged in a stepped shape. When the air guide tube fins 41 are arranged in a stepped shape, a sieve-like structure is provided at the horizontal position of the air guide tube fins 41 and the air guide tube 4.

[0059] The heat exchanger 3 in this embodiment is arranged in a cylindrical structure, and the outer wall of the heat exchanger 3 is provided with a heat exchanger fin 31. The other end of the heat exchanger 3 is installed with a ring sleeve 32, and the ring sleeve 32 is in contact with the tile 8; a primary flue gas heat exchange channel is formed between the outer wall of the heat exchanger 3 and the air and flue gas deflector cavity 22 and the flue gas deflector cavity 51.

[0060] In this embodiment, a baffle plate 75 is installed at one end of the burner core 7, a refractory material protective layer 76 is provided at the other end of the burner core 7, and the end cooperates with the tile 8, a boss 73 is installed on the baffle plate 75, a center hole 70 is provided on the boss 73, a plurality of primary air holes 71 are provided in the circumferential direction of the boss 73, and the plurality of primary air holes 71 are all provided on the baffle plate 75, the number of the primary air holes 71 is m, and the value range of m is 4-12, and one end of the primary air hole 71 is connected to the heat exchanger 3, the other end of the primary air hole 71 is connected to the combustion chamber 80, a plurality of diverter plates 74 are arranged on the outer wall of the burner core 7, and the plurality of diverter plates 74 are arranged in a circular array along the axis of the burner core 7, and a secondary air duct 72 exists between two adjacent diverter plates 74, the number of the secondary air ducts 72 is n, and the value range of n is 3-24, one end of the secondary air duct 72 is connected to the inner cavity of the heat exchanger 3, and the other end of the secondary air duct 72 is connected to the combustion chamber 80.

[0061] A combustion chamber 80 is provided on the tile 8 in the present embodiment. The combustion chamber 80 is arranged in a trumpet-shaped structure. A plurality of air channels 81 are arranged circumferentially of the combustion chamber 80. The number of the air channels 81 is x, and the value range of x is 4-16. The air channels 81 are arranged obliquely. The angle between the axis of the air channel 81 and the axis of the combustion chamber 80 is α, and the value range of α is 0-20°. A plurality of smoke channels 82 are arranged on the outer wall of the tile 8. The smoke channels 82 are arranged in a fan-shaped structure. The number of the smoke channels 82 is y, and the value range of y is 4-12. The two ends of the combustion chamber 80 are a combustion chamber outlet 801 and a combustion chamber inlet 802, respectively.

[0062] In this embodiment, a primary gas pipe 61 is provided on the burner end cover 6, and a secondary gas pipe 62 is installed in the primary gas pipe 61. One end of the primary gas pipe 61 is communicated with the gas interface 60 on the gas end cover 6, and one end of the secondary gas pipe 62 is exposed at the burner end cover 6. The other end of the primary gas pipe 61 is connected to the burner core 7, and the other end of the secondary gas pipe 62 penetrates the burner core 7 and is located in the tile 8. An ignition device 63 is installed on the burner end cover 6, and one end of the ignition device 63 is exposed at the burner end cover 6, and the other end of the ignition device 63 is connected to the burner core 7; the primary gas pipe 61 and the ignition device 63 are both located in the air guide tube 4, and a flame monitoring device 64 is installed on the burner end cover 6.

[0063] Specifically, external air enters the primary air preheating channel between the air cylinder 9 and the smoke exhaust pipe 10 through the air inlet 90, and exchanges heat with the smoke exhaust pipe 10 to perform primary preheating on the air; then, the external air enters the secondary air preheating channel formed between the burner housing 1 and the air and smoke deflector 2, and exchanges heat with the air and smoke deflector 2 to perform secondary preheating on the air; the preheated air then enters the final air preheating channel between the air guide cylinder 4 and the heat exchanger 3, and exchanges heat with the heat exchanger 3 to perform final preheating on the air. A portion of the final preheated air enters the combustion chamber 80 through the burner core 7, and is mixed and burned with the fuel gas entering the combustion chamber 80 from the burner core 7, and the other portion enters the heating space through the air channel 81 and is mixed and burned with the unburned fuel gas ejected from the combustion chamber 80.

[0064] The external gas enters the burner end cover 6 from the gas interface 60, enters the combustion chamber 80 through the burner core 7 via the first-level gas pipe 61 and mixes with the gas in the combustion chamber 80. The incompletely burned mixture is ejected through the combustion chamber outlet 801 into the heating space and the other part enters the heating space through the air channel 81 to be mixed and burned again.

[0065] The smoke in the heating space enters the primary smoke heat exchange channel formed between the heat exchanger 3 and the smoke guide cavity 51 and the inner cavity of the air smoke deflector 2 through the smoke channel 82, and enters the air smoke deflector inner cavity 22 and the air smoke deflector outer cavity 21 of the air smoke deflector 2 after heat exchange with the heat exchanger 3. After heat exchange with the smoke again, the smoke is discharged to the external smoke exhaust system through the smoke exhaust pipe 10, and undergoes final heat exchange with the smoke exhaust pipe 10.

[0066] Alternatively, the external gas may directly enter the combustion chamber 80 through the secondary gas pipe 62, and the high-speed injected gas is mixed with the air in the combustion chamber 80 and the air injected from the air channel 81 to form a diffusion combustion mode, which is controlled by an external gas valve.

[0067] The multi-stage preheating dual-mode low NOx self-preheating burner has the following advantages:

[0068] 1. The air cylinder 9 is mounted outside the smoke exhaust pipe 10. The air after primary heat exchange is outside the smoke exhaust pipe 10, and the high-temperature smoke is inside the smoke exhaust pipe 10. Therefore, the outer wall temperature of the air cylinder 9 is low, and the air passes through the spiral channel, and the heat exchange path is lengthened; after primary preheating, the air enters the burner housing 1 and the air and smoke deflector 2 for secondary heat exchange, and finally enters the heat exchanger 3 and the air and smoke deflector 2 for final heat exchange, which greatly improves the heat exchange path, heat exchange area and heat exchange efficiency, increases the air preheating temperature, increases the combustion efficiency, and improves the thermal efficiency and energy utilization rate.

[0069] 2. During the primary and secondary preheating of the air, the air circulation channel is outside the air and smoke deflector 2, and the smoke circulation channel is inside the air and smoke deflector 2, which reduces the smoke circulation resistance and makes the smoke exhaust smoother. At the same time, it also greatly reduces the temperature of the outer wall of the burner, increases the service life of the burner, improves the working environment of the burner, and makes the burner more user-friendly.

[0070] 3. Fins are arranged on the outer wall of the air guide tube 4, and various structural forms are adopted, such as circular array, spiral, combination of spiral and circular array, and stepped. They can be flexibly selected according to different working conditions and occasions to optimize the heat exchange efficiency and performance of the burner.

[0071] 4. The preheated air can be injected into the combustion chamber 80 through the burner core 7 for the first and second times to mix with the primary gas, and the tertiary air can be injected directly into the heating space through the air channel 81 to mix with the mixed air and gas ejected from the combustion chamber 80 for combustion, thus truly achieving multi-stage mixing and minimizing NOx generation. Alternatively, the preheated air and the secondary gas can be injected into the heating space to form diffusion combustion, resulting in ultra-low NOx generation.

[0072] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the present invention. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. Technicians in the technical field of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A multi-stage preheating dual-mode low NOx self-preheating burner, comprising a burner housing (1), an air and smoke deflector (2), a heat exchanger (3), an air deflector tube (4), a smoke deflector device (5), a burner end cover (6), a burner core (7), a tile (8), an air tube (9) and a smoke exhaust pipe (10), characterized in that: The burner housing (1) is mounted on one end of the smoke guide device (5), the tile (8) is mounted on the other end of the smoke guide device (5), the burner core (7) is mounted on the tile (8), the air smoke guide (2) is mounted in the burner housing (1), and the air smoke guide (2) cooperates with the smoke guide device (5), one end of the heat exchanger (3) is mounted on the air smoke guide (2), the other end of the heat exchanger (3) is connected to the inlet end of the tile (8), one end of the air guide tube (4) is mounted on the burner housing (1), the other end of the air guide tube (4) is located in the heat exchanger (3), one end of the burner end cover (6) and one end of the air tube (9) are both mounted on the burner housing (1), the smoke exhaust pipe (10) is mounted in the air tube (9), and the smoke exhaust pipe (10) is connected to the air smoke guide (2); An air smoke deflector outer cavity (21) is arranged outside the air smoke deflector (2), an air smoke deflector inner cavity (22) is arranged inside the air smoke deflector (2), the air smoke deflector outer cavity (21) is communicated with the air smoke deflector inner cavity (22), a burner shell inner cavity (11) is arranged inside the burner shell (1), an air cylinder inner cavity (91) is arranged on the outer wall of the smoke exhaust pipe (10) and the inner wall of the air cylinder (9), the air cylinder inner cavity (91) is communicated with the burner shell inner cavity (11), and one end of the smoke exhaust pipe (10) is communicated with the air smoke deflector outer cavity (21); The smoke guide device (5) is provided with a smoke guide cavity (51), the smoke guide cavity (51) is in communication with the air smoke guide cavity (22), the other end of the heat exchanger (3) is located in the smoke guide cavity (51), the burner core (7) and the tile (8) are both located in the smoke guide cavity (51) and are matched with the other end of the heat exchanger (3); The tile (8) is provided with a combustion chamber (80), the combustion chamber (80) being arranged in a bell-mouth-shaped structure, a plurality of air passages (81) being arranged in the circumferential direction of the combustion chamber (80), a plurality of smoke passages (82) being arranged on the outer wall of the tile (8), and the two ends of the combustion chamber (80) being a combustion chamber outlet (801) and a combustion chamber inlet (802), respectively; External air enters the primary air preheating channel between the air cylinder (9) and the smoke exhaust pipe (10) through the air inlet (90), and performs heat exchange with the smoke exhaust pipe (10) to perform primary preheating on the air; then, the air enters the secondary air preheating channel between the burner housing (1) and the air and smoke deflector (2), and performs heat exchange with the air and smoke deflector (2) to perform secondary preheating on the air; the preheated air then enters the final air preheating channel between the air deflector (4) and the heat exchanger (3), and performs heat exchange with the heat exchanger (3) to perform final preheating on the air; a portion of the final preheated air enters the combustion chamber (80) through the burner core (7), and is mixed and burned with the fuel gas entering the combustion chamber (80) through the burner core (7); the other portion of the air enters the heating space through the air channel (81), and is mixed and burned with the unburned fuel gas ejected from the combustion chamber (80). External fuel gas enters the burner end cover (6) through the fuel gas interface (60), enters the combustion chamber (80) through the primary fuel gas pipe (61) and the burner core (7), and mixes with the gas in the combustion chamber (80). The incompletely burned mixture is ejected through the combustion chamber outlet (801) into the heating space, and the other part enters the heating space through the air channel (81) and is mixed and burned again. The smoke in the heating space enters the primary smoke heat exchange channel formed between the heat exchanger (3) and the smoke guide cavity (51) and the inner cavity of the air smoke guide (2) through the smoke channel (82), and after heat exchange with the heat exchanger (3), enters the air smoke guide inner cavity (22) and the air smoke guide outer cavity (21) of the air smoke guide (2), and after heat exchange with the smoke again, the smoke is discharged to the external smoke exhaust system through the smoke exhaust pipe (10), and finally heat exchange is performed with the smoke exhaust pipe (10).

2. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 1 is characterized in that: The burner core (7) is connected to the inlet end of the tile (8), the heat exchanger (3) is installed in the air and smoke deflector (2), and the air deflector tube (4) is installed in the heat exchanger (3).

3. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 2 is characterized in that: An air final preheating channel is formed between the outer wall of the air guide tube (4) and the inner wall of the heat exchanger (3).

4. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 1 is characterized in that: The outer cavity (21) of the air and smoke deflector is a secondary smoke heat exchange channel, and an air secondary preheating channel is formed between the outer wall of the air and smoke deflector (2) and the inner wall of the burner housing (1).

5. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 1 is characterized in that: The other end of the smoke exhaust pipe (10) is a smoke outlet (103), the interior of the smoke exhaust pipe (10) is a smoke outlet channel (102), the outer wall of the smoke exhaust pipe (10) is provided with a smoke exhaust pipe fin (101), the smoke exhaust pipe fin (101) is located in the air cylinder inner cavity (91), the air cylinder (9) is provided with an air inlet (90), and the air inlet (90) is connected to the air cylinder inner cavity (91).

6. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 5 is characterized in that: The smoke exhaust pipe fin (101) is arranged in a spiral structure, and the smoke exhaust pipe fin (101) divides the air cylinder inner cavity (91) into air primary preheating channels.

7. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 1 is characterized in that: The shell of the smoke guide device (5) is made of metal material, and refractory material is arranged inside the shell.

8. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 1 is characterized in that: The shell of the flue gas guide device (5) is made of a heat-resistant alloy material, and the shell is connected to the burner housing (1) via a flange.

9. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 1 is characterized in that: The outer wall of the air guide tube (4) is provided with air guide tube fins (41).

10. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 9 is characterized in that: The air guide tube fins (41) are arranged in a circular array; or the air guide tube fins (41) are arranged in a spiral shape; or the air guide tube fins (41) are arranged in a combination of a circular array and a spiral shape; or the air guide tube fins (41) are arranged in a stepped shape. When the air guide tube fins (41) are arranged in a stepped shape, a sieve-like structure is arranged at a horizontal position between the air guide tube fins (41) and the air guide tube (4).

11. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 1 is characterized in that: The heat exchanger (3) is arranged in a cylindrical structure, the outer wall of the heat exchanger (3) is provided with heat exchanger fins (31), and the other end of the heat exchanger (3) is installed with a ring sleeve (32), and the ring sleeve (32) is in contact with the tile (8).

12. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 11, characterized in that: A primary smoke heat exchange channel is formed between the outer wall of the heat exchanger (3), the inner cavity (22) of the air and smoke deflector, and the smoke deflection cavity (51).

13. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 1 is characterized in that: A baffle (75) is installed at one end of the burner core (7), a refractory material protective layer (76) is provided at the other end of the burner core (7), and the end cooperates with the tile (8), a boss (73) is installed on the baffle (75), a center hole (70) is provided on the boss (73), a plurality of primary air holes (71) are provided in the circumferential direction of the boss (73), the plurality of primary air holes (71) are all provided on the baffle (75), the number of the primary air holes (71) is m, and the value range of m is 4-12, and one end of the primary air hole (71) is connected to the heat exchanger (3), the other end of the primary air hole (71) is connected to the inner cavity of the heat exchanger (3), the other end of the primary air hole (71) is connected to the combustion chamber (80), a plurality of diverter plates (74) are arranged on the outer wall of the burner core (7), the plurality of diverter plates (74) are arranged in a circular array along the axis of the burner core (7), a secondary air duct (72) is present between two adjacent diverter plates (74), the number of the secondary air ducts (72) is n, and the value range of n is 3-24, one end of the secondary air duct (72) is connected to the inner cavity of the heat exchanger (3), and the other end of the secondary air duct (72) is connected to the combustion chamber (80).

14. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 1, characterized in that: The number of the air channels (81) is x, and the value range of x is 4-16. The air channels (81) are arranged obliquely, and the angle between the axis of the air channel (81) and the axis of the combustion chamber (80) is α, and the value range of α is 0-20°. The number of the smoke channels (82) is y, and the value range of y is 4-12.

15. The multi-stage preheating dual-mode low NOx self-preheating burner according to claim 1, characterized in that: The burner end cover (6) is provided with a primary gas pipe (61), a secondary gas pipe (62) is installed in the primary gas pipe (61), one end of the primary gas pipe (61) is in communication with a gas interface (60) on the gas end cover (6), one end of the secondary gas pipe (62) is exposed from the burner end cover (6), the other end of the primary gas pipe (61) is connected to the burner core (7), the other end of the secondary gas pipe (62) penetrates the burner core (7) and is located in the tile (8), an ignition device (63) is installed on the burner end cover (6), one end of the ignition device (63) is exposed from the burner end cover (6), the other end of the ignition device (63) is connected to the burner core (7), and a flame monitoring device (64) is installed on the burner end cover (6).

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