A multi-stage annular slot cyclone premixed porous body combustion combustion device

Abstract

This invention relates to a combustion device using a multi-stage annular swirl premixed porous combustion system. It effectively solves the problems of high combustion intensity, high combustion temperature, high combustion efficiency, and complete and thorough premixed combustion with low nitrogen oxides under reduced oxygen concentration. The air-gas distribution annulus and horizontally inclined nozzles form a strong swirling, uniform slit airflow. Multiple nozzles and multiple stages of air-gas contact each other thoroughly and uniformly, completing a thorough and uniform premixing process. The combustion chamber is filled with a combustion-supporting porous body, allowing the premixed gas to rapidly enter the porous body via circumferential swirling and vertical recirculation, achieving high-intensity and high-temperature combustion within the porous body. The top airflow regulating and distribution pipe ensures uniform and effective airflow regulation by ensuring circumferentially uniform flow into and out of the combustion device. This invention achieves rapid, thorough, and uniform premixing of gas and air, utilizing a combustion-supporting porous body to complete high-intensity and high-temperature premixed combustion, thus meeting the technical requirements of high efficiency, energy saving, low nitrogen oxides, and environmental protection for industrial furnaces.

Description

Technical Field

[0001] This invention relates to combustion devices, particularly multi-stage annular swirl premixed porous combustion, which is especially suitable for use in various types of industrial furnaces and kilns for heat utilization to obtain high-temperature flue gas through the thorough mixing and combustion of low-calorific-value coal gas. Background Technology

[0002] Industrial furnaces and kilns are essential thermal equipment for heat utilization in industrial production. The combustion device that provides heat energy to these furnaces and kilns determines whether they can achieve excellent performance in terms of high efficiency, energy saving, environmental protection, and low emissions. High-efficiency, low-emission combustion devices refer to those that can achieve efficient and controllable complete combustion while effectively reducing the generation of nitrogen oxides (NOx) during combustion. This is also an important research direction for combustion devices. Therefore, in addition to achieving rapid and uniform mixing and high-intensity stable combustion, the structural design of industrial furnace burners must also allow for the adjustment and controllability of the combustion process for different types of fuel gas. Ultimately, while obtaining high-temperature heat energy, NOx emissions must comply with relevant regulations. Clearly, controllable NOx combustion places higher technical demands on combustion devices, combustion chamber structures, and their rational configuration.

[0003] A review of various gas burners used in industrial furnaces reveals numerous technical problems. For instance, the tendency towards diffusion combustion (where gas and air are mixed and burned simultaneously) or semi-premixed combustion (where partial premixing occurs) results in insufficient and uneven mixing and combustion of gas and air. This leads to inadequate and ineffective control of air volume (oxygen concentration) during combustion, not only failing to improve combustion intensity and efficiency but also causing excessive nitrogen oxide content in flue gas at lower combustion temperatures (average temperatures). The root cause lies in the presence of localized high temperatures and excessively high oxygen content in the flue gas during combustion. In long-flame combustion, the air side of the flame front experiences localized high temperatures and abundant oxygen concentrations, preventing sufficient and uniform premixing, let alone molecular-level premixing. This inevitably results in continued mixing and combustion of air and gas in the high-temperature flue gas, creating an opportunity for sufficient oxygen and nitrogen to combine and generate nitrogen oxides. As the above analysis clearly shows, achieving fully uniform premixing of air and gas, and effectively controlling the oxygen concentration during combustion are crucial in the structural design of low-NOx combustion devices. To this end, a multi-stage annular swirl premixing porous combustion device is proposed. Utilizing this device's multi-stage annular swirl premixing mechanism and the regenerative porous structure filling the combustion chamber, the air-gas flow is formed into a fully uniform, strongly swirling upward airflow, which then deflects back into the regenerative porous body for preheating and ignition. Under the action of the formed rotating vortex rings, a self-reinforcing combustion process is achieved within the porous body. This results in superenthalpy combustion within the porous body, creating high-temperature heat storage and further creating a more suitable combustion environment for subsequent combustion processes. The enhanced combustion process and the generated high temperature can reduce the excess air coefficient under fully premixed conditions, further reducing the oxygen concentration in the high-temperature flue gas after combustion, thereby reducing the amount of nitrogen oxides generated in the flue gas. This process is a mutually reinforcing positive feedback process until a dynamic energy equilibrium is reached. Therefore, for gas fuel burners, only when air and gas are fully premixed and the combustion process is in a swirling (recirculating) preheating combustion airflow structure environment, and then the combustion process is enhanced and promoted by setting up a heat storage porous body (porous medium), can a fully and completely premixed combustion with high combustion intensity, high combustion temperature, high combustion efficiency, and low nitrogen oxide content be achieved with reduced oxygen concentration. This is the true meaning of a high-intensity, high-temperature, and high-efficiency combustion process with low nitrogen and pollution-free emissions. However, there have been no public reports of such combustion equipment to date. Summary of the Invention

[0004] In view of the above situation and to overcome the defects of the prior art, the purpose of this invention is to provide a combustion device for multi-stage annular swirl premixed porous combustion, which can effectively solve the problems of high combustion intensity, high combustion temperature, high combustion efficiency, and low nitrogen oxide content in complete and sufficient premixed combustion under reduced oxygen concentration.

[0005] The technical solution proposed by this invention to solve the above-mentioned problems is a combustion device for multi-stage annular swirl premixed porous combustion, comprising a bell-shaped structure composed of a hemispherical combustion chamber wall and a cylindrical burner wall, the internal space of which is a combustion chamber through which combustion gas flows, and the combustion chamber is filled with a combustion-supporting porous body; an airflow regulating and distribution pipe is provided at the top of the combustion chamber wall, the upper closed section of the airflow regulating and distribution pipe is inverted U-shaped, the internal space of the pipe is an airflow regulating and distribution chamber, which is interconnected with the combustion chamber through an airflow inlet and outlet, and the airflow regulating and distribution chamber is horizontally symmetrically arranged on both sides of the outer wall of the airflow regulating and distribution pipe. The combustor features a connected hot gas outlet and a regulating gas inlet. A stable gas regulating distribution pipe support ring is located at the lower periphery where it connects to the combustion chamber wall. Horizontally spaced gas and air inlets are located on both sides of the burner wall's outer wall, respectively connecting to the outer sides of the gas and air distribution rings within the burner wall. Circumferentially distributed, horizontally inclined air nozzles are located on the inner side of the air distribution ring, communicating with the annular swirl of air within the burner wall. The bottom of the annular swirl is closed, and the two sides gradually narrow with openings at the top, with the inner side forming a premixed gas swirl ring wall. Inside the gas distribution ring channel, there are three layers of horizontally inclined gas nozzles evenly distributed circumferentially from bottom to top. These three layers of nozzles are the primary, secondary, and tertiary horizontal gas nozzles, respectively. They are interconnected with the primary, secondary, and premixed gas swirl rings within the burner wall, and the premixed gas swirl ring channel itself. The connections are all located on the lower outer side of the corresponding ring, while the inner side remains a premixed gas swirl ring wall. The cross-sectional characteristics of the primary and secondary premixed gas swirl rings are the same as those of the air swirl rings. The premixed gas swirl ring channel is located between the combustion chamber wall and the premixed gas swirl ring wall. The upper part of the ring space is open; the upper part of the air swirl ring gap gradually narrows and opens upward to connect to the bottom of the first-stage swirl ring gap of the premixed gas, the upper part of the first-stage swirl ring gap gradually narrows and opens upward to connect to the bottom of the second-stage swirl ring gap of the premixed gas, and the upper part of the second-stage swirl ring gap gradually narrows and opens upward to connect to the bottom of the premixed gas swirl ring channel, thereby realizing the mutual communication between the swirl ring gaps and the mutual communication between the ring gaps and the ring channel; a combustion-supporting porous body support is provided in the bottom of the burner wall, and the through hole in the center of the combustion-supporting porous body support in the lower part of the combustion chamber is set as the combustion gas outlet that communicates with the lower part of the burner.

[0006] The combustion device of this invention is characterized by: firstly, the formation of a uniform, swirling airflow through an air-gas distribution ring and horizontally inclined nozzles; secondly, the thorough and uniform premixing of air and gas through multi-stage, fully and uniform contact between multiple nozzles and multiple stages of air and gas; thirdly, the combustion chamber being filled with a combustion-supporting porous body, allowing the premixed gas to rapidly enter the porous body in a circumferential swirling and vertical recirculation flow state, achieving a high-intensity and high-temperature combustion process within the porous body; and fourthly, the airflow regulating and distribution pipe at the top also flows into and out of the combustion device in a circumferentially uniform manner, effectively ensuring the uniformity and effectiveness of the regulating airflow. Replacing various gaseous fuel combustion devices in traditional industrial furnaces with this invention's burner achieves rapid, thorough, and uniform premixing of gas and air, and enables high-intensity and high-temperature premixed combustion with the aid of the combustion-supporting porous body, thereby meeting the technical requirements of high efficiency, energy saving, low nitrogen, and environmental protection for industrial furnaces, resulting in significant economic and social benefits. Attached Figure Description

[0007] Figure 1 This is a front cross-sectional view of the combustion device of the present invention; Figure 2 This is a top-view cross-sectional view of the height of the gas inlet pipe in the combustion device of the present invention. Figure 3 This is a top cross-sectional view of the height of the air inlet pipe of the combustion device of the present invention; Figure 4 This is a top cross-sectional view of the combustion device of the present invention, showing the adjustment of the airflow inlet height. Detailed Implementation

[0008] The following detailed description of the specific structure and implementation method of the combustion device is provided in conjunction with the accompanying drawings.

[0009] Depend on Figure 1-4As shown, the present invention discloses a combustion device for multi-stage annular swirl premixed porous combustion, comprising a bell-shaped structure composed of a hemispherical combustion chamber wall 1 and a cylindrical burner wall 2, the internal space of which is a combustion chamber 1-1 through which combustion gas flows, and the combustion chamber is filled with a combustion-supporting porous body 1-2; an airflow regulating and distributing pipe 1-4 is provided at the top of the combustion chamber wall 1, the upper closed section of the airflow regulating and distributing pipe 1-4 is inverted U-shaped, and the internal space of the pipe is an airflow regulating and distributing chamber 1-5, which is interconnected with the combustion chamber 1-1 through an airflow inlet and outlet 1-3; hot gas outlets 1-6 and regulating gas inlets are horizontally symmetrically arranged on both sides of the outer wall of the airflow regulating and distributing pipe 1-4, which are connected to the airflow regulating and distributing chamber 1-5. At the lower periphery of the airflow regulating and distribution pipe 1-4, where it connects to the combustion chamber wall 1, a stable airflow regulating and distribution pipe support ring 1-8 is provided. On both sides of the outer wall of the burner wall 2, horizontally spaced gas inlet pipes 2-3 and air inlet pipes 2-2 are provided, respectively connected to the outer inner sides of the gas distribution ring channel 2-5 and air distribution ring channel 2-4 within the burner wall 2. On the inner side of the air distribution ring channel 2-4, there are circumferentially distributed horizontally inclined air nozzles 2-6, which are interconnected with the air swirl ring 2-7 within the burner wall. The bottom of the ring 2-6 is closed, and both sides gradually narrow with openings at the top. The inner side is a premixed gas swirl ring wall 2-1. The inner side of the gas distribution ring channel 2-5 has... The upper three layers are horizontally inclined gas nozzles evenly distributed circumferentially. These three nozzle layers are the primary gas nozzle 2-8, the secondary gas nozzle 2-10, and the tertiary gas nozzle 2-12. They are interconnected with the primary premixed gas swirl annular seam 2-9, the secondary premixed gas annular seam 2-11, and the premixed gas swirl annular channel 2-13 within the burner wall 2. The connections are all located on the lower part of the outer side of the corresponding annular seam, while the inner side remains the premixed gas swirl annular wall 2-1. The cross-sectional characteristics of the primary premixed gas swirl annular seam 2-9 and the secondary premixed gas annular seam 2-11 are the same as those of the air swirl annular seam 2-7. The premixed gas swirl annular channel 2-13 is the connection between the combustion chamber wall 1 and the premixed gas swirl annular wall 2-1. The upper part of the ring space is open; the upper part of the air swirl ring slit 2-7 gradually narrows and opens upward to connect to the bottom of the premixed gas first-stage swirl ring slit 2-9, the upper part of the premixed gas first-stage swirl ring slit 2-9 gradually narrows and opens upward to connect to the bottom of the premixed gas second-stage swirl ring slit 2-11, the upper part of the premixed gas second-stage swirl ring slit 2-11 gradually narrows and opens upward to connect to the bottom of the premixed gas swirl ring channel 2-13, thereby realizing the mutual communication between the swirl ring slits and the mutual communication between the ring slits and the ring channel; a combustion-supporting porous body support 2-14 is provided in the bottom of the burner wall 2, and the through hole in the center of the combustion-supporting porous body support in the lower part of the combustion chamber 1-1 is set as the combustion gas outlet 2-15 that communicates with the lower part of the burner.

[0010] To ensure effectiveness and ease of use, the combustion chamber wall 1 and the burner wall 2 are hollow bodies with concentric circular cross-sections. Both are made of heat-resistant metal shells and are constructed or cast from the outside in with heat-insulating materials and high-temperature resistant and thermal shock resistant refractory materials.

[0011] The combustion-supporting porous body 1-2 is placed in the combustion chamber and supported by the combustion-supporting porous body support 2-14 made of refractory material. It is made of porous material with high porosity, such as refractory spheres, checker bricks or ceramic honeycomb. The combustion-supporting porous body 1-2 can be removed from the combustion chamber when necessary. It is required that the airflow can flow smoothly and have sufficient heat exchange with the airflow, and promote the full mixing of different gases in it.

[0012] The hot air outlet 1-6 and the regulating air inlet 1-7 are horizontally and symmetrically connected to the airflow regulating and distribution chamber 1-5, and their connection method is either horizontal and vertical or horizontally inclined.

[0013] The gas inlet pipe 2-3 and air inlet pipe 2-2 are circular pipes made of heat-resistant metal material. They are evenly distributed on the outside of the burner wall 2 and are connected to the gas distribution ring 2-5 and the air distribution ring 2-4 horizontally and vertically or horizontally and inclinedly, respectively.

[0014] The premixed ring wall 2-1 is a structure combining cylindrical and conical shapes, constructed or cast from high-temperature and thermal shock resistant refractory materials. Its top outer side forms a premixed gas swirl ring channel 2-13 with the combustion chamber wall 1. The middle outer side forms the inner side of the air swirl ring seam 2-7, the first-stage premixed gas swirl ring seam 2-9, and the second-stage premixed gas swirl ring seam 2-11, respectively. The lower part gradually becomes conical, and the inner side of the wall forms a sliding contact state with the outer side of the combustion-supporting porous body support 2-14.

[0015] The horizontally inclined air nozzle 2-6 is a corner channel structure with a rectangular cross section. Its inlet section is perpendicular to the inner side of the air distribution ring 2-4, and its outlet section is inclined to the outer side of the air swirl ring 2-7.

[0016] The horizontally inclined primary gas nozzle 2-8 is a corner channel structure with a rectangular cross-section. Its inlet section is perpendicular to the inner side of the gas distribution ring 2-5, and its outlet section is inclined to the outer side of the primary gas swirl ring 2-9. The secondary gas nozzle 2-10 and the tertiary gas nozzle 2-12 have the same structure and similar arrangement as the primary gas nozzle 2-8. If necessary, the number of multi-stage gas horizontal nozzles can be reduced to one stage or increased to more stages, and the number of premixed gas swirl rings can be reduced or increased accordingly.

[0017] In specific implementation, the combustion device of the multi-stage annular swirl premixed porous combustion described in this invention is installed at the corresponding position in the industrial furnace; when air enters the air distribution annulus from the air inlet pipe at a horizontal angle, it forms a circumferentially uniform airflow state in a swirling flow mode, and then enters the air swirl annulus through the horizontally inclined air nozzle, forming a strong swirling gap flow in the annulus, and then enters the first-stage swirl annulus of the premixed gas upwards, and then sequentially enters the second-stage swirl annulus of the premixed gas and the premixed gas swirl annulus; at the same time, the gas... The gas enters the gas distribution ring channel at a horizontal angle from the gas inlet pipe. Within this ring, a circumferentially uniform airflow is formed by a swirling flow. The gas then passes through three horizontally inclined nozzles (first-stage, second-stage, and third-stage) from bottom to top, entering the first-stage and second-stage swirling annular gaps of the premixed gas system, respectively. There, it is injected at an angle and mixes with the swirling airflow from the air swirling annular gap, the first-stage premixed gas from the first-stage swirling annular gap, and the second-stage premixed gas from the second-stage swirling annular gap. The premixed gas undergoes stage-by-stage premixing to form a fully and uniform premixed airflow with a strong swirling flow state. The swirling premixed airflow rises along the dome and begins to be preheated and ignited locally. The swirling flow at the dome then reverses downwards, forming a swirling vortex motion and rapidly entering the combustion-supporting porous body. Due to the porous body and the fluid space it occupies, compared to a space without a porous body, it has the characteristics of high density, high heat capacity, high heat and mass exchange rate, and flow complexity. This allows the air-gas premixed airflow to complete combustion quickly, uniformly, and fully within it. The swirling vortex flow formed by the combustion device structure increases the residence time and the interaction between fluids, further enhancing the combustion process and increasing the combustion temperature. Since the strong swirling porous body combustion effectively reduces the amount of combustion air required, and the reduction in the amount of combustion air helps to increase the combustion temperature, the reduction in the oxygen concentration in the high-temperature flue gas effectively inhibits the formation of nitrogen oxides at high combustion temperatures. This constitutes a dynamic self-reinforcing combustion system, the equilibrium state of which depends on the selection of the burner's design parameters and the degree of performance optimization.

[0018] During implementation, the three-stage premixing structure of the combustion device can be increased or decreased according to the usage conditions. It can have only one stage of premixing structure or multiple stages of premixing structure; the combustion-supporting porous body set in the combustion chamber can also be removed when necessary.

[0019] Clearly, the unique burner structure of staged swirl gap premixing of air and gas, combined with the filling of the dome combustion chamber with combustion-supporting porous bodies to achieve swirl-enhanced combustion structure in the porous bodies, is undoubtedly a combustion device that achieves high combustion intensity, high combustion temperature, high combustion efficiency and low nitrogen oxides for low-calorific-value gas. It is also a combustion device that has achieved full optimization of structure and performance based on porous media combustion theory and practice.

[0020] Through continuous experimental verification and gradual practical application, this combustion device can achieve fully uniform swirl premixing of air and gas, and efficient, high-temperature, and high-intensity premixed combustion. It can increase combustion temperature while reducing flue gas emissions, thereby improving the thermal efficiency of the heat utilization system. Due to the significant improvement in combustion performance, the performance of the heat utilization equipment is effectively enhanced, thereby increasing equipment capacity and improving its effective utilization rate. Based on the combustion device's ability to achieve fully uniform, strong swirl premixed combustion, it not only increases combustion temperature and efficiency while reducing the amount of combustion air, but also significantly reduces the formation of nitrogen oxides (NOx) in the flue gas, with emissions decreasing to 30 mg / m³. 3 The following results meet the requirements for ultra-low emissions. It is clear that this invention is indeed a high-performance combustion device with high combustion intensity, high combustion temperature, high combustion efficiency, and low pollution emissions, offering significant economic and social benefits.

[0021] It should be noted that the above are merely examples given to illustrate specific implementations of the present invention, and are not intended to limit the scope of protection of the present invention. Any technical solution that is essentially the same as the present invention by means of equivalent or equivalent substitution shall fall within the scope of protection of the present invention.

Claims

1. A combustion device for multi-stage annular swirl premixed porous combustion, comprising a bell-shaped structure composed of a hemispherical combustion chamber wall (1) and a cylindrical burner wall (2) arranged vertically, wherein the internal space is a combustion chamber (1-1) through which combustion gas flows, and the combustion chamber is filled with a combustion-supporting porous body (1-2), characterized in that, An airflow regulating and distributing pipe (1-4) is installed at the top of the combustion chamber wall (1). The upper closed section of the airflow regulating and distributing pipe (1-4) is inverted U-shaped, and the space inside the pipe is the airflow regulating and distributing chamber (1-5). It is connected to the combustion chamber (1-1) through the airflow inlet and outlet (1-3). On both sides of the outer wall of the airflow regulating and distributing pipe (1-4), a hot air outlet (1-6) and a regulating air inlet (1-7) connected to the airflow regulating and distributing chamber (1-5) are horizontally symmetrically arranged. The hot air outlet (1-6) and the regulating air inlet (1-7) are horizontally symmetrically connected to the airflow regulating and distributing chamber (1-5), and the connection method is horizontal-vertical or horizontally inclined. The airflow regulating and distributing pipe (1-4) is located below... A stable airflow regulating and distributing pipe support ring (1-8) is provided at the connection between the periphery of the burner and the combustion chamber wall (1); gas inlet pipes (2-3) and air inlet pipes (2-2) are provided on both sides of the outer wall of the burner wall (2), and are connected to the outer side of the gas distribution ring (2-5) and air distribution ring (2-4) in the burner wall (2), respectively; there are horizontally inclined air nozzles (2-6) evenly distributed around the inner side of the air distribution ring (2-4), and they are connected to the air swirl ring gap (2-7) in the burner wall. The bottom of the ring gap is closed, and the two sides are gradually narrowed with an opening at the top. The inner side is a premixed gas swirl ring wall (2-1). The cyclone ring wall (2-1) is a structure combining a cylindrical and a conical shape, constructed or cast from high-temperature and thermally shock resistant refractory materials. Its top outer side forms a premixed gas cyclone ring channel (2-13) with the combustion chamber wall (1). The middle outer side forms the inner surfaces of the air cyclone ring seam (2-7), the first-stage premixed gas cyclone ring seam (2-9), and the second-stage premixed gas cyclone ring seam (2-11). The lower part gradually becomes conical, and the inner side of the wall forms a sliding contact with the outer side of the combustion-supporting porous body support (2-14). The inner side of the gas distribution ring channel (2-5) has three layers of horizontally inclined gas nozzles evenly distributed circumferentially from bottom to top. These three layers of nozzles are the first-stage gas nozzles (2-11, 2-12, 2-13, 2-14, 2-15, 2-16, 2-17, 2-18, 2-19 ... 8) The gas secondary horizontal nozzle (2-10) and the gas tertiary horizontal nozzle (2-12) are respectively connected to the premixed gas primary swirl ring seam (2-9), the premixed gas secondary swirl ring seam (2-11) and the premixed gas swirl ring channel (2-13) in the burner wall (2). The connection parts are all on the lower part of the outer side of the corresponding ring seam, and the inner side is still the premixed gas swirl ring wall (2-1). The cross-sectional characteristics of the premixed gas primary swirl ring seam (2-9) and the premixed gas secondary swirl ring seam (2-11) are the same as the structure of the air swirl ring seam (2-7). The premixed gas swirl ring channel (2-13) is an annular space with an upper opening between the combustion chamber wall (1) and the premixed gas swirl ring wall (2-1).The upper part of the air swirl annular slot (2-7) gradually narrows and opens upwards to connect with the bottom of the first-stage premixed gas swirl annular slot (2-9). The upper part of the first-stage premixed gas swirl annular slot (2-9) gradually narrows and opens upwards to connect with the bottom of the second-stage premixed gas swirl annular slot (2-11). The upper part of the second-stage premixed gas swirl annular slot (2-11) gradually narrows and opens upwards to connect with the bottom of the premixed gas swirl annular channel (2-13), thereby realizing the interconnection between the swirl annular slots and the interconnection between the annular slots and the annular channel. A combustion-supporting porous body support (2-14) is provided in the bottom of the burner wall (2). The through hole in the center of the combustion-supporting porous body support at the bottom of the combustion chamber (1-1) is... The combustion gas outlet (2-15), connected to the lower part of the burner, forms a uniform, strongly swirling slit airflow through the air-gas distribution ring and horizontally inclined nozzles. This airflow, through multi-nozzle, multi-stage, thorough and uniform contact with the air-gas, achieves a thorough and uniform premixing process. The combustion chamber is filled with a porous combustion-supporting body, allowing the premixed gas to rapidly enter the porous body in a circumferential swirling and vertical recirculation flow, achieving a thorough and uniform high-intensity, high-temperature combustion process within the porous body. The top airflow regulating and distribution pipe ensures uniform flow into and out of the combustion device in a circumferential manner, effectively guaranteeing the uniformity and effectiveness of the regulating airflow.

2. The combustion device for multi-stage annular slit swirl premixed porous combustion according to claim 1, characterized in that, The combustion chamber wall (1) and the burner wall (2) are hollow bodies with concentric cross sections and circular shapes. They are both made of heat-resistant metal shells and are constructed or cast from the outside in with heat-insulating materials and high-temperature and heat-shock resistant refractory materials.

3. The combustion device for multi-stage annular slit swirl premixed porous combustion according to claim 1, characterized in that, The combustion-supporting porous body (1-2) is placed in the combustion chamber and supported by a combustion-supporting porous body support (2-14) made of refractory material. It is made of porous material with high porosity, such as refractory spheres, checker bricks or ceramic honeycomb.

4. The combustion device for multi-stage annular slit swirl premixed porous combustion according to claim 1, characterized in that, The gas inlet pipe (2-3) and air inlet pipe (2-2) are circular pipes made of heat-resistant metal material. Multiple pipes are evenly distributed on the outside of the burner wall (2) and are connected to the gas distribution ring (2-5) and air distribution ring (2-4) respectively, either horizontally and vertically or horizontally and inclinedly.

5. The combustion device for multi-stage annular slit swirl premixed porous combustion according to claim 1, characterized in that, The horizontally inclined air nozzle (2-6) is a corner channel structure with a rectangular cross section. Its inlet section is perpendicular to the inner side of the air distribution ring (2-4), and its outlet section is inclined to the outer side of the air swirl ring (2-7).

6. The combustion device for multi-stage annular slit swirl premixed porous combustion according to claim 1, characterized in that, The gas primary horizontal nozzle (2-8) is a corner channel structure with a horizontally inclined rectangular cross section. Its inlet section is perpendicular to the inner side of the gas distribution ring (2-5), and its outlet section is inclined to the outer side of the premixed gas primary swirl ring (2-9).

7. The combustion device for multi-stage annular slit swirl premixed porous combustion according to claim 1, characterized in that, The gas secondary horizontal nozzle (2-10), gas tertiary horizontal nozzle (2-12) and gas primary horizontal nozzle (2-8) have the same structure and similar arrangement. Alternatively, the number of multi-stage gas horizontal nozzles may be reduced to one stage or increased to more stages, and the number of premixed gas swirl rings may be reduced or increased accordingly.

Images