Staged porous media burner

Abstract

The present application provides a graded porous medium burner, which relates to the technical field of porous medium burners. The graded porous medium burner includes a combustion chamber and a plurality of combustion-supporting gas pipes. The combustion chamber has a gas distribution combustion cavity, and the combustion chamber is provided with a mixed gas inlet and a heat release port along its axial direction, which are respectively connected to the gas distribution combustion cavity. The heat release port is used to output flue gas and heat to the outside of the combustion chamber. The gas distribution combustion cavity is provided with a gas distribution assembly and a porous medium combustion layer arranged in sequence along the gas flow direction, with the direction from the mixed gas inlet to the heat release port as the positive direction; a plurality of combustion-supporting gas pipes are arranged at intervals along the circumference of the heat release port, and the gas outlet of each combustion-supporting gas pipe extends in the positive direction, and the gas outlet direction of each combustion-supporting gas pipe gradually approaches the axis of the combustion chamber. The above arrangement can be used to mix the combustion-supporting gas with the flue gas of the primary combustion for secondary combustion, while avoiding backfire and effectively reducing pollutants such as NOx.

Description

Technical Field

[0001] The present application relates to the technical field of porous medium burners, and in particular to a graded porous medium burner. Background Art

[0002] Porous media combustion is a combustion method that adds porous media to the burner. The burner with porous media has three heat transfer modes: convection, heat conduction and radiation. The temperature in the combustion area tends to be uniform, maintaining a relatively stable temperature gradient. It has a high volumetric heat intensity while maintaining stable combustion.

[0003] However, in actual use, porous media burners inevitably emit pollutants such as NOx, which pollutes the environment. How to effectively reduce pollutants such as NOx is a technical problem that needs to be solved in this field. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a graded porous media burner, which can improve the technical problem of high emissions of pollutants such as NOx.

[0005] An embodiment of the present application provides a staged porous medium burner, which includes a combustion chamber and a plurality of combustion-supporting gas pipes.

[0006] The combustion chamber has a gas distribution combustion chamber, and the combustion chamber is provided with a mixture gas inlet and a heat release port along its axial direction, which are respectively connected to the gas distribution combustion chamber. The heat release port is used to output smoke and heat to the outside of the combustion chamber. The gas distribution combustion chamber is provided with gas distribution components and porous medium combustion layers arranged in sequence along the gas flow direction, and the direction from the mixture gas inlet to the heat release port is taken as the positive direction.

[0007] Multiple combustion-supporting gas pipes are arranged at intervals along the circumference of the heat release port, and the gas outlet of each combustion-supporting gas pipe extends in the positive direction. The gas outlet direction of each combustion-supporting gas pipe gradually approaches the axis of the combustion chamber, so that the combustion-supporting gas and flue gas output by the multiple combustion-supporting gas pipes are mixed and can utilize heat for secondary combustion.

[0008] In the technical solution of the embodiment of the present application, the above-mentioned flue gas refers to the flue gas of primary combustion. By arranging multiple combustion-supporting pipes in the circumferential direction of the heat release port, on the one hand, multiple combustion-supporting pipes are used to output combustion-supporting gas in the circumferential direction, which is conducive to the uniform mixing of combustion-supporting gas and the flue gas of primary combustion, and is convenient for the secondary combustion to be sufficient, so as to reduce pollutants such as NOx. On the other hand, since the combustion-supporting pipes are located in the circumferential direction of the heat release port, not only can the combustion-supporting gas pipes be preheated to ensure that the output combustion-supporting gas has a certain temperature, which is more conducive to combustion after mixing with the flue gas, but also the problem of flashback of the graded porous medium burner caused by the heat conduction of the inner wall of the combustion chamber, which produces a large amount of NOx and other pollutants, can be avoided. At the same time, the gas outlet of each combustion-supporting pipe extends in the positive direction, and the gas outlet direction of each combustion-supporting pipe gradually approaches the axis of the combustion chamber, which is not only conducive to the mixing of combustion-supporting gas and the flue gas of primary combustion, but also avoids flashback during secondary combustion, and further avoids the generation of pollutants such as NOx.

[0009] In some embodiments, the graded porous medium burner further includes: a gas pipe sequentially arranged in the porous medium combustion layer and the gas distribution assembly, the gas inlet end of the gas pipe extending out of the combustion chamber through the heat release port, and the gas outlet end of the gas pipe connected to a plurality of combustion-supporting gas pipes. Through the arrangement of the gas pipe, the combustion-supporting gas ejected from the combustion-supporting gas pipe can be mixed with the smoke of the primary combustion, and can be induced by the air ejected from the gas pipe, further enhancing the mixing effect of the smoke of the primary combustion and the combustion-supporting gas, increasing the flow rate of the smoke of the secondary combustion, and improving the efficiency of the secondary combustion.

[0010] In some embodiments, the gas delivery pipe is coaxially arranged with the combustion chamber. Since the gas outlet of each combustion-supporting gas pipe extends in the positive direction and the gas outlet direction of each combustion-supporting gas pipe gradually approaches the axis of the combustion chamber, the output combustion-supporting gas eventually approaches the axis of the combustion chamber. Therefore, the gas delivery pipe is coaxially arranged with the combustion chamber, which can effectively improve the injection efficiency.

[0011] In some embodiments, the gas distribution assembly includes a gas distribution plate, the gas distribution plate is provided with a plurality of gas distribution holes, the gas distribution plate has a first region surrounding the gas transmission pipe, and a second region surrounding the first region, wherein the density of the gas distribution holes in the first region is greater than the density of the gas distribution holes in the second region. By adopting the above-mentioned different densities of the gas distribution holes in different regions, it is possible to avoid the generation of black spots in the porous medium combustion layer located near the gas transmission pipe due to the effect of the gas transmission pipe when in a combustion state.

[0012] In some embodiments, a plurality of combustion-supporting gas pipes are arranged rotationally symmetrically along the center of the heat release port, and the plurality of combustion-supporting gas pipes are configured to mix the output airflow with the flue gas in a swirl shape. The uniformity of the output combustion-supporting gas can be improved by the rotationally symmetrical arrangement, and the plurality of combustion-supporting gas pipes are configured to mix the output airflow in a swirl shape, which is conducive to fully and evenly mixing the output combustion-supporting gas with the secondary flue gas, thereby improving the effect and efficiency of the secondary combustion.

[0013] In some embodiments, the side of the porous medium combustion layer away from the gas distribution assembly is taken as the combustion surface, and the orthographic projection of each combustion-supporting gas pipe on the plane where the combustion surface is located has a first end and a second end, the first end is located on the side of the second end close to the center of the combustion surface, the line connecting the first end and the second end is taken as the line A, the line connecting the second end and the center is taken as the line B, and the angle between the line A and the line B is 30-60°. By setting the angle between the line A and the line B to 30-60°, it is ensured that the combustion-supporting gas swirl effect is good.

[0014] In some embodiments, each combustion-supporting gas pipe includes a supporting pipe and an outlet pipe that are interconnected, the supporting pipe is arranged parallel to the axis of the combustion chamber, the outlet pipe is used to output the combustion-supporting gas, and an angle of 90-150° is formed between the supporting pipe and the outlet pipe. Through the above arrangement, it is ensured that the output combustion-supporting gas swirls toward the side away from the combustion surface, avoiding the increase of pollutant content such as NOx in the primary combustion flue gas caused by backfire.

[0015] In some embodiments, the porous medium combustion layer includes a porous plate layer and a porous medium ceramic layer, the porous plate layer is located on the side of the porous medium ceramic layer close to the gas distribution component, and the porous plate layer is provided with a plurality of holes, each of which has a diameter of ≤1.2 mm. The diameter of the hole is ≤1.2 mm, that is, the diameter of the hole is smaller than the quenching diameter of the gas combustion, so that the graded porous medium burner has a structural anti-flashback capability through the porous plate layer, ensures the sufficiency of combustion, and reduces pollutants such as NOx in the primary combustion flue gas.

[0016] In some embodiments, the total cross-sectional area of ​​the plurality of holes is less than or equal to the total cross-sectional area of ​​the mixed gas inlet. Through the above arrangement, the space between the mixed gas inlet and the porous plate layer can be in a relatively high positive pressure state, so that after the mixed gas passes through the porous plate layer, the gas flow of the mixed gas after passing through each hole tends to be consistent, effectively improving the uniformity of combustion and avoiding the emission of pollutants such as NOx caused by uneven combustion.

[0017] In some embodiments, the graded porous medium burner also includes a premixing chamber having a premixing cavity, the premixing chamber having a first end and a second end arranged oppositely along its axial direction, the first end having an auxiliary gas inlet and a fuel gas inlet, the second end having a mixed gas outlet corresponding to and connected to the mixed gas inlet, at least two groups of swirl components are provided in the premixing chamber, at least two groups of swirl components are located between the first end and the second end, and the swirl directions of any two adjacent groups of swirl components are different. By having any two adjacent groups of swirl components have different swirl directions, the mixing effect of the fuel gas and the auxiliary gas is effectively enhanced, the mixing efficiency is high, and the mixing is more uniform after mixing, which is convenient for full combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic structural diagram of a first-viewing angle of view of a staged porous medium burner provided in Example 1;

[0020] Figure 2 A schematic structural diagram of the hierarchical porous medium burner provided in Example 1 from a second perspective;

[0021] Figure 3 A schematic diagram of the structure of the air distribution plate provided in Example 1;

[0022] Figure 4 This is a schematic diagram of the orthographic projection structure of the gas pipe provided in Example 1;

[0023] Figure 5 A schematic structural diagram of a first-viewing angle of view of a staged porous medium burner provided in Example 2;

[0024] Figure 6 A schematic diagram of the assembly of the gas delivery pipe and the gas distribution assembly from a first perspective provided in Example 2;

[0025] Figure 7 A schematic diagram of the assembly of the gas delivery pipe and the gas distribution assembly from a second perspective provided in Example 2;

[0026] Figure 8 This is a schematic structural diagram of the second perspective of the graded porous media burner provided in Example 2.

[0027] Icons: 1000a-staged porous medium burner; 1000b-staged porous medium burner; 10-combustion chamber; 100-gas distribution combustion chamber; 101-gas distribution chamber; 103-combustion chamber; 110-mixed gas inlet; 120-heat release port; 130-gas distribution assembly; 131-dividing plate; 133a-gas distribution plate; 133b-gas distribution plate; 1331-gas distribution hole; 1333-first area; 1334-second area; 140-gas transmission pipe; 141-insulation sleeve; 143 -gas transmission pipe body; 150-porous medium combustion layer; 151-porous plate layer; 153-porous medium ceramic layer; 20-premixing chamber; 200-fuel-supporting gas inlet; 210-fuel-supporting gas inlet; 230-swirl assembly; 240-air inlet; 250-fuel-supporting gas interlayer; 251-receiving pipe; 30-fuel-supporting gas pipe; 301-first end; 302-second end; 310-supporting pipe; 320-gas outlet pipe; 330-fuel-supporting gas chamber; 332-receiving part; 40-insulation layer; 50-ignition electrode. DETAILED DESCRIPTION

[0028] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0029] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "upper", "lower", "positive", "inner", "outer", "clockwise", "counterclockwise", "axial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0032] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0033] Example 1

[0034] See also Figure 1 The embodiment of the present application provides a staged porous medium burner 1000a, which includes: a combustion chamber 10 and a plurality of combustion-supporting gas pipes 30.

[0035] The combustion chamber 10 has a gas distribution combustion chamber 100 along its axial direction. The combustion chamber 10 is provided with a mixed gas inlet 110 and a heat release port 120 respectively connected to the gas distribution combustion chamber 100. The heat release port 120 is used to output smoke and heat to the outside of the combustion chamber 10. The gas distribution combustion chamber 100 is provided with a gas distribution assembly 130 and a porous medium combustion layer 150 arranged in sequence along the gas flow direction. The direction from the mixed gas inlet to the heat release port is taken as the positive direction; a plurality of combustion-supporting gas pipes 30 are arranged at intervals along the circumference of the smoke exhaust heat release port 120, and the gas outlet of each combustion-supporting gas pipe 30 extends toward the positive direction, and the gas outlet direction of each combustion-supporting gas pipe 30 gradually approaches the axis of the combustion chamber 10, so that the combustion-supporting gas and the smoke output by the plurality of combustion-supporting gas pipes 30 are mixed and can use the heat for secondary combustion. The material of the combustion chamber 10 is generally a heat-conducting material such as metal, which is not limited here.

[0036] The gas flow direction refers to the direction in which the mixed gas flows from the mixed gas inlet 110 to the heat release port 120 .

[0037] In the above arrangement, by arranging a plurality of combustion-supporting pipes 30 around the heat release port 120, on the one hand, it is conducive to uniform mixing of the combustion-supporting gas with the flue gas of the primary combustion, which is convenient for sufficient secondary combustion to reduce pollutants such as NOx. On the other hand, since the combustion-supporting pipes 30 are located around the heat release port 120, not only can the combustion-supporting gas pipes 30 be preheated to ensure that the output combustion-supporting gas has a certain temperature, which is more conducive to combustion after mixing with the flue gas, but also the problem of flashback of the graded porous medium burner 1000a caused by the heat conduction of the material constituting the combustion chamber 10, which produces a large amount of NOx and other pollutants, can be avoided. At the same time, the gas outlet of each combustion-supporting pipe 30 extends in the forward direction, and the gas outlet direction of each combustion-supporting pipe 30 gradually approaches the axis of the combustion chamber 10, which is not only conducive to the mixing of the combustion-supporting gas with the flue gas of the primary combustion, but also avoids flashback during secondary combustion, further avoiding the generation of pollutants such as NOx.

[0038] Among them, the mixed gas inlet refers to the inlet for inputting the mixed gas, the mixed gas refers to the evenly mixed fuel gas and supporting fuel gas, the fuel gas includes natural gas, the supporting fuel gas is oxygen-containing gas, for example, the supporting fuel gas is air, and the flue gas refers to the flue gas discharged from the primary combustion of the supporting fuel gas.

[0039] See also Figure 1 as well as Figure 2 , the graded porous medium burner 1000a also includes a premixing chamber 20, which has a first end and a second end arranged oppositely along its axial direction, the first end is provided with an auxiliary gas inlet 200 and a gas inlet 210, and the second end is provided with a mixed gas outlet corresponding to and connected to the mixed gas inlet 110, and at least two groups, such as two groups, three groups, etc., of swirl components 230 are provided in the premixing chamber 20, at least two groups of swirl components 230 are located between the first end and the second end, and the swirl directions of any two adjacent groups of swirl components 230 are different. That is, the setting of the premixing chamber 20 is used to provide the combustion chamber 10 with a mixed gas, wherein the setting of any two adjacent groups of swirl components 230 with different swirl directions is conducive to uniform mixing of the auxiliary gas and the gas.

[0040] Among them, in order to ensure a good mixing effect, optionally, the swirl directions of any two adjacent groups of swirl components 230 are opposite, that is, for any two adjacent groups of swirl components 230, the swirl direction of one group of swirl components 230 is clockwise, and the swirl direction of the other group of swirl components 230 is counterclockwise.

[0041] In this embodiment, based on the premise that the swirl directions of any two adjacent groups of swirl components 230 are opposite, two groups of swirl components 230 are provided in the premixing chamber 20. On the premise of ensuring uniform mixing, on the one hand, the cost is effectively saved, and on the other hand, the structure of the graded porous medium burner 1000a is simplified.

[0042] In order to further improve the mixing efficiency, the axis of the auxiliary gas inlet 200 and the axis of the gas inlet 210 intersect, for example, the axis of the auxiliary gas inlet 200 and the axis of the gas inlet 210 are perpendicular, and different flow directions are more conducive to uniform mixing.

[0043] See also Figure 2 as well as Figure 3Since the amount of supporting combustion gas is excessive during actual use, the premixing chamber 20 optionally forms an air intake portion 240 between the supporting combustion gas inlet 200 and a group of swirl components 230 closest to the first end, and the graded porous medium burner 1000a has a gas interlayer 250 surrounding the air intake portion 240, and the gas interlayer 250 has a receiving pipe 251 for receiving the gas, and the supporting combustion gas cavity 330 is provided with a plurality of rows of gas inlet groups connected to the gas interlayer 250, and each row of the gas inlet groups has a plurality of gas inlets 210 arranged at intervals along the circumference of the supporting combustion gas cavity 330, and in two adjacent gas inlet groups, the gas inlet 210 of one gas inlet group is staggered with the gas inlet 210 of the other gas inlet group, and the density of the two groups of gas inlets 210 is different, so as to effectively improve the initial mixing effect.

[0044] See also Figure 1 The air distribution assembly 130 includes a diverter plate 131 and an air distribution plate 133a.

[0045] The gas distribution plate 133a divides the gas distribution combustion chamber 100 into the gas distribution chamber 101 and the combustion chamber 103. The diverter plate 131 is located in the gas distribution chamber 101 and arranged corresponding to the mixed gas inlet 110. The edge of the diverter plate 131 is at least partially not in contact with the combustion chamber 10. The diverter plate 131 has a diverter hole (not shown) for initially diverting the mixed gas from the mixed gas inlet 110, so that the mixed gas diffuses around the diverter plate 131. There is a gap between the diverter plate 131 and the gas distribution plate 133a to leave enough space for the mixed gas to further diffuse. The porous medium combustion layer 150 is located in the combustion chamber 103 and there is also a gap between it and the gas distribution plate 133a.

[0046] See also Figure 3 The air distribution plate 133a is provided with a plurality of air distribution holes 1331, the opening rate of the air distribution plate 133a is 30% to 40%, and the opening diameter ranges from 3mm to 5mm, so that the conveying speed and direction of the mixed gas after passing through the air distribution plate 133a tend to be consistent, so as to ensure uniform conveying of the mixed gas to the porous medium combustion layer 150.

[0047] The material of the air distribution plate 133a can be metal, for example, the air distribution plate 133a is a 2 mm thick steel plate with uniform holes.

[0048] The porous medium combustion layer 150 includes a porous plate layer 151 and a porous medium ceramic layer 153. The porous plate layer 151 is located on one side of the porous medium ceramic layer 153 close to the gas distribution assembly 130. The porous plate layer 151 is provided with a plurality of holes (not shown), and the diameter of each hole is ≤1.2 mm. The diameter of the hole is ≤1.2 mm, that is, the diameter of the hole is smaller than the quenching diameter of the gas combustion, so that the staged porous medium burner 1000a has a structural anti-flashback capability through the porous plate layer 151, ensuring the sufficiency of combustion and reducing pollutants such as NOx in the primary combustion flue gas.

[0049] The porous plate layer 151 is made of porous alumina with good heat insulation effect.

[0050] Optionally, the total cross-sectional area of ​​the plurality of holes is ≤ the cross-sectional area of ​​the mixed gas inlet 110 . The above arrangement ensures that the air distribution cavity 101 is in a relatively high positive pressure state, which is beneficial for maintaining a consistent flow rate of the mixed gas in each hole after the mixed gas enters the porous plate layer 151 .

[0051] It should be noted that during actual use, the flow rate of the mixed gas in the porous plate layer 151 should be much greater than the combustion rate of the fuel gas. That is, generally speaking, the flow rate of the mixed gas in the holes of the porous plate layer 151 should be greater than 3m / s to avoid the risk of flashback of the porous medium combustion layer 150.

[0052] The porous medium ceramic layer 153 is, for example, silicon carbide porous ceramic. During use, the mixed gas ratio should be controlled to ensure that the excess air coefficient is 0.6-0.95. A lower excess air coefficient can be used to reduce the combustion temperature in the silicon carbide porous ceramic and create a reducing atmosphere. This method can prolong the oxidation and aging of silicon carbide in a high-temperature oxidizing environment, and the combustion state with low combustion temperature and reducing atmosphere can reduce the emission of nitrogen oxides.

[0053] The porous dielectric ceramic layer 153 seals the heat release port 120 , and the side of the porous dielectric ceramic layer 153 facing away from the gas distribution component 130 serves as a combustion surface, wherein the combustion surface is arranged corresponding to the heat release port 120 and is circular.

[0054] Optionally, multiple combustion-supporting gas pipes 30 are rotationally symmetrically arranged along the center of the heat release port 120, and the multiple combustion-supporting gas pipes 30 are constructed so that the output airflow is mixed with the flue gas in a swirl shape. Through the rotationally symmetrical arrangement, the uniformity of the output combustion-supporting gas can be improved. At the same time, the multiple combustion-supporting gas pipes 30 are constructed so that the output airflow is in a swirl shape, which is beneficial to fully and evenly mixing the output combustion-supporting gas with the secondary flue gas, thereby improving the effect and efficiency of the secondary combustion.

[0055] Swirl flow refers to the output combustion-supporting gas flowing in a spiral shape toward the side away from the mixed gas.

[0056] Optionally, each combustion-supporting gas pipe 30 includes a supporting pipe 310 and an air outlet pipe 320 that are interconnected, wherein the supporting pipe 310 is arranged parallel to the axis of the gas distribution combustion chamber 100, and the air outlet pipe 320 is used to output the combustion-supporting gas, and an angle of 90-150° is formed between the supporting pipe 310 and the air outlet pipe 320. The supporting pipe 310 and the air outlet pipe 320 are both straight pipes, and the connection between the supporting pipe 310 and the air outlet pipe 320 is smoothly transitioned to ensure the smoothness of the output of the combustion-supporting gas.

[0057] See also Figure 4 The orthographic projection of each combustion-supporting gas pipe 30 on the plane where the combustion surface is located has a first end 301 and a second end 302, the first end 301 is located on the side of the second end 302 close to the center of the combustion surface, the line connecting the first end 301 and the second end 302 is used as the line A, and the line connecting the second end 302 and the center is used as the line B, and the angle α between the line A and the line B is 30-60°, for example, the angle α between the line A and the line B is 30°, 40°, 50° or 60°, etc., and the angle between the line A and the line B is set to ensure that the combustion-supporting gas is output from the multiple combustion-supporting gas pipes 30 in the form of a swirl.

[0058] Among them, since the support tube 310 is arranged parallel to the axis of the gas distribution combustion chamber 100, the orthographic projection of the combustion-supporting pipe 30 on the plane where the gas distribution plate 133a is located is actually the orthographic projection of the gas outlet pipe 320 on the plane where the gas distribution plate 133a is located. At this time, the connecting line A is actually the orthographic projection of the axis of the gas outlet pipe 320 on the plane where the gas distribution plate 133a is located.

[0059] The plurality of combustion-supporting gas pipes 30 can be independently connected to the components providing the combustion-supporting gas. For ease of use and simplified structure, please refer to Figure 1 as well as Figure 2 The staged porous medium burner 1000a further includes a shell which is at least partially arranged around the combustion chamber and forms a combustion-supporting cavity 330 with the combustion chamber.

[0060] The combustion-supporting chamber 330 is connected to the supporting tubes 310 of the plurality of combustion-supporting tubes 30 to provide combustion-supporting tubes 30 with combustion-supporting gas. The combustion-supporting chamber 330 is provided with a receiving portion 332 for connecting with a component for providing combustion-supporting gas and for receiving combustion-supporting gas. In this embodiment, the combustion-supporting chamber 330 is arranged around the circumference of the premixing chamber 20 near one end of the receiving portion 332.

[0061] Optionally, the graded porous medium burner 1000a includes a heat preservation layer 40 surrounding the porous medium ceramic layer 153, and the heat preservation layer 40 is embedded in the gas distribution combustion chamber 100 to insulate the porous medium ceramic layer 153. At the same time, the graded porous medium burner 1000a also includes an ignition electrode 50 located at the heat release port 120, and the specific configuration can refer to the relevant technology and is not limited here.

[0062] The working process of the graded porous medium burner 1000a includes: the gas first enters the gas interlayer 250 through the receiving pipe 251, then enters the premixing chamber 20 through multiple gas inlets 210 to be preliminarily mixed with the primary combustion gas entering the premixing chamber 20 from the combustion gas inlet 200, and is mixed evenly after being forced to mix by the swirl of the swirl component 230 to form a mixed gas. The mixed gas enters the gas distribution combustion chamber 100 through the mixed gas inlet 110, is blocked by the diverter plate 131 and diffuses into the gas distribution plate 133a, and enters the holes of the porous plate layer 151 after passing through the gas distribution plate 133a. After passing through the porous plate layer 151, the axial speed of the mixed gas tends to be consistent, and after passing through these holes, it enters the porous medium ceramic layer 153 for primary combustion. The secondary combustion gas enters the combustion gas chamber 330 from the receiving part 332, and is spirally ejected through the combustion gas pipe 30 to form a swirl and mix with the primary combustion flue gas, and then undergoes secondary combustion.

[0063] Example 2

[0064] See also Figure 5 This embodiment provides a hierarchical porous medium burner 1000b, which is different from the embodiment 1 mainly in that it further includes a gas pipe 140 sequentially arranged in the porous medium combustion layer 150 and the gas distribution assembly 130, the gas inlet end of the gas pipe 140 extends out of the combustion chamber 10 through the heat release port 120, and the gas outlet end of the gas pipe 140 is connected with a plurality of combustion-supporting gas pipes 30 to provide combustion-supporting gas to each combustion-supporting gas pipe 30. Through the arrangement of the gas pipe 140, the combustion-supporting gas sprayed from the combustion-supporting gas pipe 30 can be mixed with the smoke of the primary combustion and can be ejected by the air sprayed from the gas pipe 140, thereby strengthening the mixing effect of the smoke of the primary combustion and the combustion-supporting gas, and at the same time increasing the flow rate of the smoke of the secondary combustion, thereby improving the efficiency of the secondary combustion.

[0065] The number of the gas delivery pipes 140 may be one or more, for example, two. Figure 5 as well as Figure 6 As shown, there is one gas pipe 140, wherein the gas pipe 140 is coaxially arranged with the combustion chamber 10, that is, the gas pipe 140 is sequentially arranged through the center of the porous medium combustion layer 150 and the center of the gas distribution assembly 130, which not only has a simple structure but also can effectively improve the injection efficiency.

[0066] Optionally, the gas delivery pipe 140 includes: a heat preservation sleeve 141 located in the porous medium combustion layer 150, and a gas delivery pipe body 143 passing through the heat preservation sleeve 141, and both ends of the gas delivery pipe body 143 extend out of the heat preservation sleeve 141 respectively.

[0067] During the actual use of the graded porous medium burner 1000b, the inventors found that during the process of mixing and burning the supporting combustion gas spirally ejected from the supporting combustion gas pipe 30 and the primary combustion flue gas, due to the action of the gas supply pipe 140, a higher pressure is easily generated in the porous medium combustion layer 150 in the area close to the gas supply pipe 140, that is, in the center of the porous medium combustion layer 150, resulting in black spots in the center of the porous medium combustion layer 150 when it is in a burning state. Therefore, the structure of the gas distribution plate 133a in Example 1 is improved, and the gas distribution plate 133b is adopted.

[0068] Among them Figure 7 As shown, the difference between the air distribution plate 133b and the air distribution plate 133a is that the air distribution plate 133b has a first area 1333 surrounding the air delivery pipe 140, and a second area 1334 surrounding the first area 1333, wherein the density of the air distribution holes 1331 in the first area 1333 is greater than the density of the air distribution holes 1331 in the second area 1334. The problem is effectively solved by adopting the method of different densities of the air distribution holes 1331 in different areas.

[0069] like Figure 5 and Figure 8 As shown, based on the setting of the gas supply pipe 140, the combustion-supporting gas in the combustion-supporting gas chamber 330 has a certain amount of heat. Therefore, in order to improve the primary combustion efficiency and to avoid interference with the gas supply pipe 140, in this embodiment, the end of the combustion-supporting gas chamber 330 close to the receiving portion 332 passes through the premixing chamber 20.

[0070] The working process of the graded porous medium burner 1000b includes: the gas first enters the gas interlayer 250 through the receiving pipe 251, then enters the premixing chamber 20 through multiple gas inlets 210 to be preliminarily mixed with the primary combustion gas entering the premixing chamber 20 through the combustion gas inlet 200, and is mixed evenly after being forced to mix by the swirl of the swirl assembly 230 to form a mixed gas. The mixed gas enters the gas distribution combustion chamber 100 through the mixed gas inlet 110, is blocked by the diverter plate 131 and diffuses into the gas distribution plate 133a, and after passing through the gas distribution plate 133a, the mixed gas enters the holes of the porous plate layer 151, and the axial speed of the mixed gas tends to be consistent, and after passing through these holes, enters the porous medium ceramic layer 153 for primary combustion. Part of the secondary combustion gas enters the combustion gas chamber 330 through the receiving portion 332, and the other part is introduced through the gas delivery pipe 140. The secondary combustion gas is spirally ejected through the combustion gas pipe 30 to form a vortex and mix with the primary combustion flue gas to perform secondary combustion.

[0071] In summary, the graded porous media burner provided in the embodiment of the present application can ensure that the output combustion-supporting gas is evenly mixed with the flue gas of the primary combustion, which facilitates sufficient secondary combustion to reduce pollutants such as NOx, while avoiding backfire during combustion to reduce pollutants such as NOx.

[0072] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hierarchical porous medium burner, characterized in that: include: The combustion chamber comprises a gas distribution combustion chamber, wherein the combustion chamber is provided with a mixed gas inlet and a heat release port respectively connected to the gas distribution combustion chamber along its axial direction, wherein the heat release port is used to output smoke and heat to the outside of the combustion chamber, and the gas distribution combustion chamber is provided with a gas distribution component and a porous medium combustion layer arranged in sequence at intervals along the gas flow direction, and the direction from the mixed gas inlet to the heat release port is taken as the positive direction; A plurality of combustion-supporting gas pipes are arranged at intervals along the circumference of the heat release port, the gas outlet of each combustion-supporting gas pipe extends toward the positive direction, and the gas outlet direction of each combustion-supporting gas pipe gradually approaches the axis of the combustion chamber, so that the combustion-supporting gas output by the plurality of combustion-supporting gas pipes is mixed with the flue gas and the heat can be used for secondary combustion; as well as An air delivery pipe, which is sequentially arranged in the porous medium combustion layer and the air delivery pipe in the air distribution assembly, wherein the air inlet end of the air delivery pipe extends out of the combustion chamber through the heat release port, and the air outlet end of the air delivery pipe is connected to the plurality of combustion-supporting gas pipes; Among them, the air distribution component includes an air distribution plate, which is provided with a plurality of air distribution holes. The air distribution plate has a first area surrounding the gas supply pipe and a second area surrounding the first area, wherein the density of the air distribution holes in the first area is greater than the density of the air distribution holes in the second area.

2. The staged porous medium burner according to claim 1, characterized in that: The gas delivery pipe is coaxially arranged with the combustion chamber.

3. The staged porous medium burner according to claim 1 or 2, characterized in that: The plurality of combustion-supporting gas pipes are rotationally symmetrically arranged along the center of the heat release port, and the plurality of combustion-supporting gas pipes are configured to allow the output airflow to be mixed with the flue gas in a swirl shape.

4. The staged porous medium burner according to claim 3, characterized in that: The side of the porous medium combustion layer facing away from the gas distribution assembly is taken as the combustion surface, and the orthographic projection of each of the combustion-supporting pipes on the plane where the combustion surface is located has a first end and a second end, and the first end is located on the side of the second end close to the center of the combustion surface, the line connecting the first end and the second end is taken as the line A, and the line connecting the second end and the center is taken as the line B, and the angle between the line A and the line B is 30-60°.

5. The staged porous medium burner according to claim 3, characterized in that: Each of the combustion-supporting gas pipes includes a supporting pipe and an air outlet pipe which are interconnected. The supporting pipe is arranged parallel to the axis of the combustion chamber. The air outlet pipe is used to output the combustion-supporting gas. An angle of 90-150° is formed between the supporting pipe and the air outlet pipe.

6. The staged porous medium burner according to claim 1 or 2, characterized in that: The porous medium combustion layer includes a porous plate layer and a porous medium ceramic layer. The porous plate layer is located on a side of the porous medium ceramic layer close to the gas distribution component. The porous plate layer is provided with a plurality of holes, and the diameter of each hole is ≤1.2 mm.

7. The staged porous medium burner according to claim 6, characterized in that: The total cross-sectional area of ​​the plurality of holes is less than or equal to the total cross-sectional area of ​​the mixed gas inlet.

8. The staged porous medium burner according to claim 1 or 2, characterized in that: The staged porous medium burner also includes a premixing chamber having a premixing cavity, wherein the premixing chamber has a first end and a second end arranged oppositely along its axial direction, the first end is provided with a combustion-supporting gas inlet and a combustion gas inlet, the second end is provided with a mixed gas outlet corresponding to and connected to the mixed gas inlet, at least two groups of swirl components are provided in the premixing cavity, the at least two groups of swirl components are located between the first end and the second end, and the swirl directions of any two adjacent groups of swirl components are different.

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