Ventilation air methane oxidation device and ventilation air methane oxidation system

Abstract

The application discloses a ventilation air methane oxidation device and a ventilation air methane oxidation system. The device is provided with a thermal oxidation unit and a catalytic oxidation unit. The thermal oxidation unit does not need power consumption, but adopts a coal powder combustion heating mode. The coal powder production is large, and the cost is low, so that the cost consumption of the ventilation air methane oxidation utilization can be effectively reduced. The low-cost coal powder combustion heating unit and the catalytic oxidation unit are combined, so that the combustion efficiency and decomposition efficiency of methane in the ventilation air methane can be improved, and compared with the single catalytic oxidation reaction, the catalyst consumption can be effectively reduced, and the catalyst cost can be reduced. The ventilation air methane oxidation device can reduce the production cost on the basis of ensuring the ventilation air methane oxidation efficiency. The ventilation air methane oxidation system can realize the recycling of the waste heat and the coal powder in the combustion chamber, and is favorable for energy saving and environmental protection.

Description

Technical Field

[0001] This invention belongs to the field of mining technology, and relates to the utilization technology of exhaust gas, particularly to an exhaust gas oxidation device and exhaust gas oxidation system. Background Technology

[0002] Coal mining releases large amounts of coalbed methane, commonly known as coalbed methane, whose main component is methane, and it is an unconventional natural gas. Effective and rational utilization of coal mine coalbed methane can alleviate the pressure on natural gas energy utilization, reduce methane emissions, and improve environmental quality.

[0003] Currently, the main technological means of utilizing methane from exhaust gas focus on the oxidation of methane, using the released heat energy to generate electricity or directly for daily residential use. Based on combustion kinetics, methane oxidation methods are mainly divided into conventional combustion methods (thermal oxidation) and catalytic combustion methods (catalytic oxidation). Conventional combustion methods generally use electric heating to provide heat energy for methane oxidation, resulting in high energy consumption, high operating costs, long processing times, and low oxidation efficiency. Catalytic combustion methods require large amounts of catalysts, which are expensive, leading to high operating costs and hindering large-scale industrial application.

[0004] Therefore, it is necessary to propose a new scheme for the oxidation and utilization of exhaust gas to solve the problem that the existing exhaust gas utilization methods have high operating costs and are not conducive to large-scale industrial application. Summary of the Invention

[0005] The purpose of this invention is to provide a novel exhaust gas oxidation device and exhaust gas oxidation system to solve the problem that the existing exhaust gas utilization methods have high operating costs and are not conducive to large-scale industrial application.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a waste gas oxidation device, comprising a sealed shell, a thermal oxidation unit, and a catalytic oxidation unit. The sealed shell is provided with a waste gas inlet and a reaction product outlet. The thermal oxidation unit includes a combustion chamber and an ignition device. The combustion chamber is provided with a pulverized coal inlet, a pulverized coal outlet, and a first heat outlet. The ignition device is used to ignite the pulverized coal in the combustion chamber. The first heat outlet communicates with the interior of the sealed shell to introduce the heat generated by the combustion of the pulverized coal into the sealed shell, thereby thermally oxidizing the methane in the waste gas. The catalytic oxidation unit includes a catalyst support with a catalyst loaded on its surface. The catalyst support is disposed inside the sealed shell and located between the waste gas inlet and the reaction product outlet. The catalyst is used to contact the methane, so that catalytic oxidation occurs simultaneously with the thermal oxidation of the methane.

[0007] Optionally, the catalyst support is a ceramic heat storage structure support, which can absorb and store the heat discharged by the thermal oxidation unit, so as to provide heat for the oxidation of methane when the thermal oxidation unit stops providing heat to the enclosed shell.

[0008] Optionally, the enclosed outer shell is a cylindrical shell, the exhaust gas inlet is located at one axial end of the cylindrical shell, and the reaction product outlet is located at the other axial end of the cylindrical shell; the combustion chamber is a cylindrical combustion chamber, which is disposed inside the cylindrical shell, and the two axial ends of the cylindrical combustion chamber are respectively arranged through the two axial ends of the cylindrical shell; the first heat outlet is disposed on the side wall of the cylindrical combustion chamber located inside the cylindrical shell; the ceramic heat storage structure carrier is hollow inside, the ceramic heat storage structure carrier is sleeved around the outer periphery of the cylindrical combustion chamber, and the inner ring of the ceramic heat storage structure carrier is provided with a first heat inlet communicating with the first heat outlet; the ceramic heat storage structure carrier is provided with an air passage for exhaust gas to pass through.

[0009] Optionally, the cylindrical outer shell is a cylindrical outer shell, and the combustion chamber is a cylindrical combustion chamber; the ceramic heat storage structure carrier is a ceramic heat storage ring plate composed of several ceramic heat storage blocks arranged in a ring at intervals, each of the ceramic heat storage blocks is a hollow structural block, and the inner ring of each of the ceramic heat storage blocks is provided with the first heat inlet hole, and the first heat outlet hole on the cylindrical combustion chamber is arranged in a one-to-one correspondence with the ceramic heat storage block; the interval between any two adjacent ceramic heat storage blocks in the ceramic heat storage ring plate constitutes the air passage gap.

[0010] Optionally, the ceramic heat storage block is one or a combination of more of the following: fan-shaped ceramic heat storage block, rectangular ceramic heat storage block, triangular ceramic heat storage block, and trapezoidal ceramic heat storage block.

[0011] Optionally, the cylindrical combustion chamber is fitted with multiple sets of ceramic heat storage ring plates at axial intervals. Any two adjacent sets of ceramic heat storage ring plates are rotated and staggered. Along the direction from the exhaust gas inlet to the reaction product outlet, all odd-numbered ceramic heat storage ring plates are aligned, and all even-numbered ceramic heat storage ring plates are aligned.

[0012] Optionally, the inner wall of the columnar shell is provided with a ceramic heat storage layer structure, which can absorb and store the heat discharged by the thermal oxidation unit, so as to provide heat for the oxidation of methane when the thermal oxidation unit stops providing heat to the enclosed shell.

[0013] Optionally, the ceramic heat storage layer structure is a hollow ceramic heat storage brick, the inner wall of the ceramic heat storage brick is provided with a second heat inlet hole, and the outer ring of the ceramic heat storage structure carrier is provided with a second heat outlet hole that communicates with the second heat inlet hole.

[0014] Optionally, the columnar combustion chamber has several protrusions on its inner wall in the area where the first heat outlet is located, so that the fluid exhibits the Coanda effect.

[0015] Optionally, the outer wall of the enclosed shell is provided with a thermal insulation structure.

[0016] This invention also proposes a waste gas oxidation system, comprising a waste heat recovery system, a pulverized coal recovery system, and the waste gas oxidation device described above. The pulverized coal inlet and outlet are respectively located at opposite axial ends of the columnar combustion chamber. The ignition device is located within the columnar combustion chamber and at the same end as the pulverized coal inlet. A third heat outlet is also provided on the columnar combustion chamber, located at the same end as the pulverized coal outlet. The waste heat recovery system communicates with the third heat outlet to recover heat discharged from the columnar combustion chamber. The pulverized coal recovery system is connected to the pulverized coal outlet to recover pulverized coal discharged from the columnar combustion chamber.

[0017] Optionally, the pulverized coal recovery system is a pulverized coal silo, which is fitted around the outer periphery of the columnar combustion chamber.

[0018] Optionally, the waste heat recovery system includes a heat-conducting pipe, a heat exchange module, and a heat exchanger connected sequentially along the heat flow direction, and the heat-conducting pipe is connected to the third heat outlet.

[0019] The present invention achieves the following technical advantages over existing technologies: The waste gas oxidation device proposed in this invention has a novel and reasonable structure, simultaneously incorporating a thermal oxidation unit and a catalytic oxidation unit. Compared to existing traditional thermal oxidation methods, the thermal oxidation unit requires no electricity consumption, instead employing pulverized coal combustion for heating. This results in high pulverized coal production and low cost, effectively reducing the cost of waste gas oxidation utilization. Furthermore, combining the low-cost pulverized coal combustion heating unit with the catalytic oxidation unit not only improves the combustion and decomposition efficiency of methane in waste gas but also effectively reduces the amount of catalyst used, lowering catalyst costs compared to a single catalytic oxidation reaction. Therefore, the aforementioned waste gas oxidation device of the present invention can simultaneously perform thermal and catalytic oxidation reactions of waste gas. These reactions complement each other, ensuring efficient waste gas oxidation while reducing production costs. This solves the problem of high operating costs associated with any single existing waste gas utilization method, hindering large-scale industrial application.

[0020] In some technical solutions disclosed in this invention, the catalyst support in the catalytic oxidation unit is set as a ceramic heat storage structure support, which can absorb and store the heat discharged from the thermal oxidation unit, so that it can still provide heat for methane oxidation when the thermal oxidation unit stops providing heat to the enclosed shell. This solution not only improves the utilization rate of heat from the thermal oxidation unit, but also provides heat for methane even when pulverized coal combustion stops. For the oxidation utilization of the same batch of exhaust gas, this solution can significantly reduce the amount of pulverized coal used compared with pure combustion heating, further reducing production costs.

[0021] The exhaust gas oxidation system proposed in this invention includes the aforementioned exhaust gas oxidation device and is equipped with a waste heat recovery system and a pulverized coal recovery system. The waste heat recovery system is connected to the third heat outlet of the combustion chamber to recover the heat discharged from the combustion chamber, thereby realizing the recovery and utilization of waste heat in the combustion chamber, which is beneficial for energy conservation and environmental protection. The pulverized coal recovery system is connected to the pulverized coal outlet of the combustion chamber to recover the pulverized coal discharged from the combustion chamber, thereby realizing the recovery and utilization of the remaining pulverized coal, which is beneficial for saving pulverized coal consumption and reducing combustion and heating costs. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of the exhaust gas oxidation device disclosed in the embodiments of the present invention.

[0024] Figure 2 This is a schematic diagram of a ceramic heat storage layer structure disposed on a closed outer shell as disclosed in an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of the thermal oxidation unit disclosed in the embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of the structure of the catalytic oxidation unit disclosed in the embodiments of the present invention.

[0027] Figure 5 This is a schematic diagram of the structure of the catalyst support located in the odd-numbered position as disclosed in the embodiments of the present invention.

[0028] Figure 6 This is a schematic diagram of the structure of the catalyst support located at an even-numbered position as disclosed in the embodiments of the present invention.

[0029] Figure 7This is a schematic diagram of the axial cross-sectional structure of the combustion chamber disclosed in an embodiment of the present invention.

[0030] The attached figures are labeled as follows: 100, Exhaust gas oxidation device; 1, Enclosed shell; 11, Exhaust gas inlet; 12, Reaction product outlet; 13, Outer wall of the shell; 14, Shell end cap; 2, Thermal oxidation unit; 21, Combustion chamber; 22, Ignition device; 23, Pulverized coal inlet; 24, First heat outlet; 25, Third heat outlet; 26, Threaded protrusion; 27, Hemispherical protrusion; 28, High-temperature bypass valve; 29, Thermocouple; 3, Catalytic oxidation unit; 31, Catalyst carrier; 32, Ceramic heat storage block; 33, First heat inlet; 34, Gas outlet; 35, Second heat outlet; 4, Ceramic heat storage layer structure; 41, Second heat inlet; 5, Heat pipe; 6, Pulverized coal bin. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] One of the objectives of this invention is to provide a novel exhaust gas oxidation device to solve the problem that existing exhaust gas utilization methods have high operating costs, which are not conducive to large-scale industrial application.

[0033] Another object of the present invention is to provide a waste gas oxidation system having the above-mentioned waste gas oxidation device.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Example 1.

[0036] like Figure 1As shown, this embodiment provides a waste gas oxidation device 100, which mainly includes a closed shell 1, a thermal oxidation unit 2, and a catalytic oxidation unit 3. The closed shell 1 is provided with a waste gas inlet 11 and a reaction product outlet 12. The thermal oxidation unit 2 includes a combustion chamber 21 and an ignition device 22. The combustion chamber 21 is provided with a pulverized coal inlet 23, a pulverized coal outlet, and a first heat outlet 24. The ignition device 22 is used to ignite the pulverized coal in the combustion chamber 21, causing the pulverized coal to burn and generate heat (i.e., hot airflow). The first heat outlet 24 is connected to the interior of the closed shell 1 to introduce the heat generated by the combustion of pulverized coal into the closed shell 1, causing the methane in the waste gas within the closed shell 1 to undergo a thermal oxidation reaction. The aforementioned catalytic oxidation unit 3 includes a catalyst support 31 with a catalyst loaded on its surface. The catalyst support 31 is disposed inside the enclosed shell 1 and located between the exhaust gas inlet 11 and the reaction product outlet 12. After the exhaust gas enters the enclosed shell 1 through the exhaust gas inlet 11, it flows toward the reaction product outlet 12. During the flow, it flows through the catalyst support 31 and comes into contact with the catalyst on the catalyst support 31. The catalyst enables methane to undergo the aforementioned thermal oxidation reaction while simultaneously undergoing catalytic oxidation. The aforementioned waste gas oxidation device 100 is a novel waste gas oxidation and utilization device. It simultaneously incorporates a thermal oxidation unit 2 and a catalytic oxidation unit 3. Compared to existing traditional thermal oxidation methods, the thermal oxidation unit 2 requires no electricity consumption, instead employing pulverized coal combustion for heating. This results in high pulverized coal production and low cost, effectively reducing costs associated with waste gas oxidation and utilization. Furthermore, combining the low-cost pulverized coal combustion heating unit (i.e., thermal oxidation unit 2) with the catalytic oxidation unit 3 not only improves the combustion and decomposition efficiency of methane in waste gas but also effectively reduces catalyst usage and costs compared to a single catalytic oxidation reaction. Therefore, the waste gas oxidation device 100 of this scheme can simultaneously perform thermal oxidation and catalytic oxidation reactions of waste gas, reducing production costs while ensuring oxidation efficiency. This solves the problem of high operating costs associated with any single waste gas utilization method, hindering large-scale industrial application.

[0037] In this embodiment, to further improve the utilization rate of the heat released by the thermal oxidation unit 2, the catalyst carrier 31 is set as a heat storage structure carrier. The specific material can be a heat storage ceramic brick, graphite, glassy carbon, or other high-temperature resistant heat storage materials. Using a heat storage ceramic brick as the material for the catalyst carrier 31 is preferred; specifically, mullite ceramic can be selected. It can absorb and store the heat discharged from the thermal oxidation unit 2, so that it can provide heat for the oxidation of methane when the thermal oxidation unit 2 stops providing heat to the enclosed shell 1. This structural arrangement not only improves the utilization rate of the heat from the thermal oxidation unit 2, but also provides heat for methane even when the pulverized coal combustion stops. For the oxidation utilization of the same batch of exhaust gas, this solution can significantly reduce the amount of pulverized coal used compared to pure combustion heating, further reducing production costs.

[0038] In this embodiment, the thermal oxidation unit 2 can be disposed outside the enclosed housing 1, on the side wall of the enclosed housing 1, or inside the enclosed housing 1. To improve the overall compactness of the exhaust gas oxidation device 100 and minimize heat loss during the transfer process, it is preferable to dispose of the thermal oxidation unit 2 inside the enclosed housing 1. Figure 1 As shown, the enclosed shell 1 is preferably a cylindrical shell. The exhaust gas inlet 11 is located at one axial end of the cylindrical shell, and the reaction product outlet 12 is located at the other axial end of the cylindrical shell. After the exhaust gas enters the cylindrical shell through the exhaust gas inlet 11, it flows along the axial direction of the cylindrical shell. Correspondingly, the combustion chamber 21 is configured as a cylindrical combustion chamber, which is located inside the cylindrical shell. The two axial ends of the cylindrical combustion chamber are respectively arranged through the two axial ends of the cylindrical shell, so that the cylindrical combustion chamber and the cylindrical shell form an inner and outer nested structure. The first heat outlet 24 is located on the side wall of the cylindrical combustion chamber located inside the cylindrical shell.

[0039] Furthermore, in this embodiment, the ceramic heat storage structure carrier (i.e., catalyst carrier 31) is hollow inside, and the ceramic heat storage structure carrier is ringed around the outer periphery of the columnar combustion chamber. The inner ring of the ceramic heat storage structure carrier is provided with a first heat inlet 33 that communicates with the first heat outlet 24. The ceramic heat storage structure carrier is generally set on the cross-section of the columnar shell. In order to increase the contact area between the catalyst and the exhaust gas, it is preferable that the catalyst is evenly distributed on the outer surface of the ceramic heat storage structure carrier, and the outer contour of the ceramic heat storage structure carrier is adapted to the inner wall contour of the columnar shell. Generally, the outer contour of the ceramic heat storage structure carrier and the inner wall contour of the columnar shell are in a gap fit. At the same time, in order to ensure the smooth passage of exhaust gas, an air passage 34 for exhaust gas to pass through can be provided in the ceramic heat storage structure carrier (i.e., catalyst carrier 31). The air passage 34 is located outside the ceramic heat storage structure carrier and does not affect the arrangement of the hollow structure inside the ceramic heat storage structure carrier.

[0040] Further, in this embodiment, the cylindrical outer shell is preferably a cylindrical outer shell, which includes a cylindrical outer shell sidewall 13 and outer shell end caps 14 sealing the axial ends of the outer shell sidewall 13. The outer shell end caps 14 are circular, and the aforementioned exhaust gas inlet 11 and reaction product outlet 12 are respectively set on the two outer shell end caps 14, as shown. Figure 1 and Figure 2 As shown. Accordingly, the combustion chamber 21 is preferably configured as a cylindrical combustion chamber, and it is arranged coaxially with the cylindrical outer shell. Thus, an annular space gap is formed between the outer wall of the cylindrical combustion chamber and the inner wall of the cylindrical outer shell to accommodate the ceramic heat storage structure carrier and the exhaust gas. Based on the above structure, the ceramic heat storage structure carrier can be adapted to be a circular or near-circular structure. It can be an integral structure, such as a circular ring with a sawtooth or petal structure on the outer ring; it can also be configured as a split structure, such as a ceramic heat storage ring plate composed of several ceramic heat storage blocks 32 arranged in a ring at intervals. Each ceramic heat storage block 32 is an independent hollow structural block. The inner ring of each ceramic heat storage block 32 (i.e., the position in contact with the outer wall of the cylindrical combustion chamber) is provided with a first heat inlet 33 communicating with its internal space. The first heat outlet 24 on the cylindrical combustion chamber is arranged one-to-one with the ceramic heat storage block 32. The interval between any two adjacent ceramic heat storage blocks 32 in the above-mentioned split structure ceramic heat storage ring plate constitutes an air passage gap 34.

[0041] Furthermore, in this embodiment, the hollow ceramic heat storage block 32 can be one or a combination of more than one of the following: a fan-shaped ceramic heat storage block, a rectangular ceramic heat storage block, a triangular ceramic heat storage block, and a trapezoidal ceramic heat storage block. That is, the catalyst carrier 31 is formed by one of the above-mentioned shapes or by at least two of the above-mentioned shapes. As a preferred embodiment, each ceramic heat storage block 32 in the catalyst carrier 31 adopts a uniform shape, such as... Figure 1 and Figure 4 As shown, each ceramic heat storage block 32 in the catalyst carrier 31 can adopt a fan-shaped structure, and the catalyst carrier 31 is generally composed of 6 to 9 fan-shaped ceramic heat storage blocks evenly arranged. Further, it is preferable that each group of catalyst carriers 31 is a ceramic heat storage ring plate composed of 8 fan-shaped ceramic heat storage blocks evenly arranged in a ring. In this case, the ceramic heat storage ring plate is a ceramic heat storage fan ring plate. The inner ring of the ceramic heat storage fan ring plate is circular and contacts and fits with the inner wall of the cylindrical combustion chamber. The outer ring of the ceramic heat storage fan ring plate is also circular and contacts or gaps and fits with the cylindrical inner wall of the cylindrical shell.

[0042] Furthermore, in this embodiment, preferably, a plurality of sets of the aforementioned ceramic heat storage ring plates are spaced apart along the axial direction on the cylindrical combustion chamber. Any two adjacent sets of ceramic heat storage ring plates have identical structures and are rotated out of alignment. Along the direction from the exhaust gas inlet 11 to the reaction product outlet 12, all the odd-numbered ceramic heat storage ring plates (i.e., the first, third, fifth, etc.) are aligned, and all the even-numbered ceramic heat storage ring plates (i.e., the second, fourth, sixth, etc.) are aligned. The gas passage openings 34 on all even-numbered ceramic heat storage ring plates are aligned one-to-one with the fan-shaped ceramic heat storage blocks on all odd-numbered ceramic heat storage ring plates, while the fan-shaped ceramic heat storage blocks on all even-numbered ceramic heat storage ring plates are aligned one-to-one with the gas passage openings 34 on all odd-numbered ceramic heat storage ring plates. Figure 4 As shown, this is a catalytic oxidation unit 3 composed of eight sets of ceramic regenerative fan ring plates. The first, third, fifth, and seventh sets of ceramic regenerative fan ring plates are coaxially aligned, as are the second, fourth, sixth, and eighth sets. Each set of ceramic regenerative fan ring plates is arranged perpendicular to the axial direction of the cylindrical combustion chamber. By rotating and staggering adjacent sets of ceramic regenerative fan ring plates, the contact area between the exhaust gas and the catalyst on each set of ceramic regenerative fan ring plates can be increased while ensuring the smooth passage of exhaust gas through each gas passage opening 34. Generally, except for the inner and outer rings, the remaining sidewalls of the fan-shaped ceramic regenerative block are loaded with catalyst for methane oxidation.

[0043] In this embodiment, to further improve the utilization rate of heat from the thermal oxidation unit 2, a ceramic heat storage layer structure 4 is also provided on the inner wall of the cylindrical shell. The ceramic heat storage layer structure 4 can be made of ceramic heat storage bricks, which can absorb and store the heat discharged by the thermal oxidation unit 2, so as to provide heat for the oxidation of methane when the thermal oxidation unit 2 stops providing heat to the closed shell 1. When the cylindrical shell is set as a cylindrical shell, the ceramic heat storage layer structure 4 adopts a cylindrical structure adapted to the inner wall of the cylindrical shell. The arrangement of the ceramic heat storage layer structure 4 not only improves the utilization rate of heat from the thermal oxidation unit 2, but also can provide heat for methane together with the ceramic heat storage structure carrier when the pulverized coal stops burning. For the oxidation utilization of the same batch of exhaust gas, this solution can further reduce the amount of pulverized coal used compared with the pure combustion heating method, and further reduce the production cost.

[0044] Furthermore, in this embodiment, the ceramic heat storage layer structure 4 is preferably composed of multiple hollow annular ceramic heat storage bricks axially spliced ​​together. The material of the annular ceramic heat storage bricks 2 can be mullite ceramic, but in actual operation, high-temperature resistant heat storage materials such as graphite and glassy carbon can also be used. The inner wall of the annular ceramic heat storage brick is provided with a second heat inlet hole 41, and the outer ring of the ceramic heat storage structure carrier is provided with a second heat outlet hole 35 communicating with the second heat inlet hole 41. Specifically, the outer ring of each fan-shaped ceramic heat storage block is provided with a second heat outlet hole 35. The heat generated by the combustion of pulverized coal in the combustion chamber of the thermal oxidation unit 2 can sequentially reach the interior of each annular ceramic heat storage brick in the ceramic heat storage layer structure 4 through the first heat outlet hole 24, the first heat inlet hole 33, the second heat outlet hole 35, and the second heat inlet hole 41 for heat storage. Preferably, the first heat outlet 24, the first heat inlet 33, the second heat outlet 35, and the second heat inlet 41 are all sealed with stainless steel. Preferably, the first heat inlet 33 and the second heat outlet 35 are formed with stainless steel plugs so that the first heat inlet 33 and the first heat outlet 24 can be inserted into each other, and the second heat outlet 35 and the second heat inlet 41 can be inserted into each other, thereby improving the structural stability of each catalyst carrier 31.

[0045] In this embodiment, to further improve the utilization rate of heat from the thermal oxidation unit 2, it is necessary to ensure that as much heat as possible is transferred from the columnar combustion chamber to each fan-shaped ceramic heat storage block. Therefore, in this embodiment, several protrusions are provided on the inner wall of the area where the first heat outlet 24 is located in the columnar combustion chamber (i.e., the area where the catalytic oxidation unit 3 is installed) to induce the Coanda effect in the fluid. The protrusions can be one or a combination of various protrusion structures such as circular protrusions, spherical protrusions, threaded protrusions, and conical protrusions.

[0046] In this embodiment, the pulverized coal inlet 23, ignition device 22, and exhaust gas inlet 11 on the combustion chamber 21 are located at the same end of the cylindrical shell, while the pulverized coal outlet and reaction product outlet 12 are located at the other end of the cylindrical shell. That is, in the exhaust gas oxidation device 100 of this scheme, the flow direction of the hot air in the combustion chamber 21 is the same as that of the exhaust gas. Of course, in actual operation, the flow direction of the hot air in the combustion chamber 21 can also be arranged in the opposite direction to the flow direction of the exhaust gas. On the inner wall of the cylindrical combustion chamber, the protrusions preferably include two types: hemispherical protrusions 27 and threaded protrusions 26. Multiple hemispherical protrusions 27 are provided and arranged circumferentially on the inner wall of the cylindrical combustion chamber. This structure is located at the uppermost part of the area where the first heat outlet 24 is opened. Threaded protrusions 26 are provided on the inner wall of the remaining positions within the area where the first heat outlet 24 is opened. Figure 7As shown, the hot airflow in the combustion chamber 21 flows from right to left, passing sequentially through the hemispherical protrusion 27 and the threaded protrusion 26. The hemispherical protrusion 27 changes the flow path of the fluid, causing it to flow along the inner wall of the combustion chamber 21. At the same time, the threaded texture of the threaded protrusion 26 enhances the viscosity between the wall and the fluid, causing the hot airflow to flow along the inner wall of the combustion chamber 21 into the interior of the fan-shaped ceramic heat storage block, and then into the ceramic heat storage layer structure 4 through the fan-shaped ceramic heat storage block.

[0047] In this embodiment, to prevent heat loss from the enclosed shell 1, an insulation structure is also provided on the outer wall of the enclosed shell 1. The enclosed shell 1 is generally made of stainless steel, and its exterior is formed by splicing carbon steel plates to form an outer shell. The outer wall of the outer shell is reinforced with structural steel, and an annular cavity is formed between the outer shell and the outer wall of the enclosed shell 1. This annular cavity is filled with ceramic fiber modules, thereby forming a heat insulation layer structure on the outer periphery of the enclosed shell 1. The two shell end caps 14 of the enclosed shell 1 are generally made of stainless steel, and they are preferably detachably connected to the stainless steel shell side wall 13 by bolts or threads to facilitate maintenance of the catalytic oxidation unit 3 and the thermal oxidation chamber 2 inside the shell. The two shell end caps 14 preferably have four exhaust gas inlets 11 and four reaction product outlets 12, respectively, for the exhaust gas to flow into and out of the annular reaction chamber inside the enclosed shell 1.

[0048] In this embodiment, a feasible design scheme for the exhaust gas oxidation device 100 is as follows: the ceramic heat storage layer structure 4 is a cylindrical structure with an outer diameter of [missing information]. The inner diameter is The outer ring radius of each sector-shaped ceramic heat storage block is The inner fan ring radius is , < ≤ ,thickness The central angle of the fan-shaped ceramic heat storage block is °, the distance between two adjacent sector-shaped ceramic heat storage blocks °, on the same plane The block-shaped ceramic heat storage block is a set of ceramic heat storage fan ring plates. The catalyst composition is selected from core-shell catalysts with palladium as the core, or high-temperature resistant catalysts such as perovskite and hexaaluminate catalysts. The cylindrical combustion chamber is made of mullite ceramic heat storage brick, and its outer ring diameter is [missing information]. , ≤ The wall has a certain thickness, and the outer wall has grooves corresponding to the ceramic heat storage fan ring plate. The grooves have first heat outlet holes 24 to prevent pulverized coal from entering the fan-shaped ceramic heat storage block with the airflow. The second heat outlet hole 35 on the outer ring of the fan-shaped ceramic heat storage block and the first heat inlet hole 33 on the inner ring are both protruding venting channels, and the channel length meets the requirements... The width satisfies Highly satisfied ∈{ | - ≤ < - }∩{ | - ≤ < }; Axial spacing between every two adjacent sets of ceramic heat storage fan ring plates cm, the rotational stagger angle between each pair of adjacent ceramic heat storage fan ring plates is .

[0049] The distance between the inner wall of the cylindrical combustion chamber and the first ring of slots Multiple hemispherical protrusions 27 are distributed at a distance of cm, and the radius of the hemispherical protrusions 27 is... = sin The number of spheres is The function of this jet is to induce the Coanda effect in the fluid, which is manifested as a slowdown in fluid velocity and the formation of adhesion. That is, the fluid deviates from its original flow direction and tends to flow along the surface of the hemispherical protrusion 27, causing the surrounding fluid to escape into this jet and flow along the wall.

[0050] The inner wall of the cylindrical combustion chamber has a spiral angle at 27 circumferences from the hemispherical protrusion. The thread protrusion is 26° or 30° ≤ °≤60° can increase the viscosity of the wall, allowing the fluid to flow through the thread and through the first heat outlet hole 24 into the interior of the fan-shaped ceramic heat storage block.

[0051] The ignition device 22, serving as a pulverized coal ignition device, includes a burner, controller, flame detector, high-temperature protection device, safety start interlock, and pulverized coal injection device. The ignition device 22 is located at the pulverized coal inlet 23 of the cylindrical combustion chamber and is equipped with a burner for igniting the pulverized coal used in the initial heating stage. The burner has a power output of 100,000 kcal / h, and the flame is proportionally adjustable to achieve proportional power output. The controller and flame detector enable fully automatic ignition based on the combustion chamber temperature. The high-temperature protection device and safety start interlock ensure safe and reliable system operation. The fuel pipeline is equipped with electromagnetic shut-off valves, pressure switches, local instruments, etc., allowing real-time monitoring of the burner's operating status. The pulverized coal injection device has an injection pressure of 10 kcal / h. At kPa, the injected pulverized coal, under the action of the blower, enters the cylindrical combustion chamber in the form of a dust cloud within the pipeline. After being ignited by the burner, it burns in a suspended state within the combustion chamber. The heat generated during combustion enters the catalyst carrier 31 and the ceramic heat storage layer structure 4 for heat storage. When the heat energy released by the combustion of pulverized coal is sufficient, the system can maintain the oxidation and decomposition conditions of exhaust gas without needing to ignite the pulverized coal for heating. At the same time, it can also output the system's waste heat, overcoming the problems of high energy consumption, high heat loss, and low conversion efficiency in the catalytic oxidation process of exhaust gas. The aforementioned ignition device 22 is a prior art and will not be described in detail here. A high-temperature bypass valve 28 can also be installed in the center of the cylindrical combustion chamber to quickly release the temperature of the combustion chamber when the combustion chamber temperature is too high.

[0052] For safety, a temperature control device is also installed in the cylindrical combustion chamber. The temperature control device includes a thermocouple 29, a temperature data acquisition module connected to one end of the thermocouple 29, and a computer for acquiring the temperature information collected by the temperature data acquisition module; multiple thermocouples 29 are installed and evenly distributed vertically inside the cylindrical combustion chamber for combustion chamber temperature control and system safety interlock.

[0053] The working process and working principle of the exhaust gas oxidation device 100 are explained in detail below, based on the above structural design. Specifically: =40 cm, =30 cm, =30 cm, =10 cm, =10 cm, 5 cm =30, =2.62 cm, 2.5 cm =1 cm, =2 cm, =8.4645 cm, =2.59 cm =30. The exhaust gas used is prepared in a gas mixing tank through methane cylinders and an air compressor, and the concentration can be adjusted according to needs.

[0054] During operation, pulverized coal is ignited by ignition device 22 to generate heat. The heat flow changes its path through the hemispherical protrusions 27 on the inner wall of the combustion chamber and flows along the inner wall surface. The spiral protrusions 26 on the wall surface enhance the viscosity between the wall surface and the fluid, allowing the heat flow to flow along the wall surface into the fan-shaped ceramic heat storage block, and then into the annular ceramic heat storage brick of the ceramic heat storage layer structure 4. A filter screen is embedded in the first heat outlet hole 24 on the side wall of the combustion chamber, which can effectively prevent pulverized coal from flowing into the fan-shaped ceramic heat storage block. Exhaust gas flows into the annular cavity between the outer wall of the combustion chamber and the inner wall of the ceramic heat storage layer structure 4 through the gas passage, and is absorbed by the ceramic heat storage layer structure 4 and the fan-shaped ceramic heat storage block. The heat stored in the ceramic heat storage blocks is used for heating. The catalyst on the surface of the fan-shaped ceramic heat storage blocks lowers the activation energy of the methane reaction, causing it to decompose into carbon dioxide, water, and heat at a lower ignition temperature. The heat generated by the reaction is stored in the annular space between the ceramic heat storage layer structure 4 and the catalytic oxidation unit 3. Within the catalytic oxidation unit, the ceramic heat storage fan-shaped ring plates are arranged in an alternating pattern, effectively increasing the contact area between the waste gas and the catalyst, while also enhancing the heat storage capacity. When there is sufficient heat energy within the waste gas oxidation device 100, the entire system can maintain the oxidation and decomposition conditions of the waste gas without needing to ignite pulverized coal for heating, and can also output the system's waste heat. During the oxidation and utilization of the waste gas, a gas chromatograph can be connected to the sealed outer shell 1 to monitor the changes in the waste gas concentration in real time, thereby reflecting the system's ability to process waste gas.

[0055] In the aforementioned process of oxidizing and utilizing waste gas, the catalyst is a core-shell structured catalyst with palladium as the core. The preferred preparation method uses tetrachloropalladium acid (Na₂PdCl₄) and cerium nitrate [Ce(NO₃)₃] as raw materials, employing an inorganic salt KBr-induced self-assembly method to generate a more stable [PdBr₄]. 2- Complexes to delay Pd 2+ The reduction of ions can adjust the size of the Pd core and effectively reduce the stability of the colloid, promoting the self-assembly of Pd and CeO2 nano-ions with weakened surface polarity into a more stable and ordered core-shell structure.

[0056] Therefore, the exhaust gas oxidation device 100 proposed in this technical solution uses inexpensive coal powder as raw material in the thermal oxidation unit 2, resulting in low cost; the catalyst carrier 31 of the catalytic oxidation unit 3 can effectively increase the contact area between exhaust gas and catalyst, and also has a strong heat storage capacity. Combined with the ceramic heat storage layer structure 4, it can simultaneously store heat, thereby realizing the absorption, storage and efficient utilization of the heat released by the thermal oxidation unit 2 and the heat generated by the methane oxidation reaction. The exhaust gas oxidation device 100 is essentially a heat exchange device.

[0057] Example 2.

[0058] This embodiment proposes a waste gas oxidation system, including a waste heat recovery system, a pulverized coal recovery system, and the aforementioned waste gas oxidation device 100. A pulverized coal inlet 23 and a pulverized coal outlet are respectively located at opposite axial ends of a columnar combustion chamber. An ignition device 22 is located within the columnar combustion chamber and at the same end as the pulverized coal inlet 23, both situated outside the enclosed outer shell 1. A third heat outlet 25 is also provided on the columnar combustion chamber, located at the same end as the pulverized coal outlet, both also situated outside the enclosed outer shell 1. The waste heat recovery system is connected to the third heat outlet 25 to recover heat discharged from the columnar combustion chamber, heat not absorbed by the ceramic heat storage block 32 and the ceramic heat storage layer structure 4, and heat carried to the third heat outlet 25 by the waste gas fluid. The pulverized coal recovery system is connected to the pulverized coal outlet to recover the pulverized coal discharged from the columnar combustion chamber, which mainly consists of unburned coal ash.

[0059] In this embodiment, the pulverized coal recovery system is a pulverized coal bin 6, which is installed on the outer periphery of the columnar combustion chamber and is mainly used to collect unburned coal ash.

[0060] In this embodiment, the waste heat recovery system includes a heat-conducting pipe 5, a heat exchange module, and a heat exchanger connected sequentially along the heat flow path. The heat-conducting pipe 5 is connected to the third heat outlet 25. The input end of the heat exchange module is connected to the output end of the heat-conducting pipe 5 to obtain the heat of the flue gas transmitted by the heat-conducting pipe 5, thereby obtaining the waste heat of the system. The output end of the heat exchange module is connected to the heat exchanger, which is used to utilize the waste heat from the system reaction and can be directly supplied to residential users.

[0061] The aforementioned waste gas oxidation system, by employing the waste gas oxidation device 100 disclosed in Example 1, can absorb, store, and efficiently utilize the heat released by the thermal oxidation unit 2 and the heat generated by the methane oxidation reaction. When there is sufficient heat energy in the system, the entire system can maintain the oxidation and decomposition conditions of waste gas without needing to ignite pulverized coal for heating. The system's waste heat energy is transferred through heat pipes, and the heat exchange module and heat exchanger are connected to utilize the system's reaction waste heat, further overcoming the problems of high energy consumption, high heat loss, and low conversion efficiency in the catalytic oxidation process of waste gas.

[0062] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0063] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A waste gas oxidation device, characterized in that, The system includes a sealed outer shell, a thermal oxidation unit, and a catalytic oxidation unit. The sealed outer shell has a waste gas inlet and a reaction product outlet. The thermal oxidation unit includes a combustion chamber and an ignition device. The combustion chamber has a pulverized coal inlet, a pulverized coal outlet, and a first heat outlet. The ignition device is used to ignite the pulverized coal in the combustion chamber. The first heat outlet communicates with the interior of the sealed outer shell to introduce the heat generated by the combustion of the pulverized coal into the sealed outer shell, thereby thermally oxidizing the methane in the waste gas. The catalytic oxidation unit includes a catalyst support with a catalyst loaded on its surface. The catalyst support is disposed inside the sealed outer shell and located between the waste gas inlet and the reaction product outlet. The catalyst is used to contact the methane, so that the methane undergoes catalytic oxidation simultaneously with thermal oxidation. The catalyst support is a ceramic heat storage structure support, which can absorb and store the heat discharged by the thermal oxidation unit, so as to provide heat for the oxidation of methane when the thermal oxidation unit stops providing heat to the enclosed shell; The enclosed outer shell is cylindrical, with the exhaust gas inlet located at one axial end and the reaction product outlet located at the other axial end. The combustion chamber is cylindrical, housed within the cylindrical outer shell, with its axial ends penetrating both ends of the cylindrical outer shell. The first heat outlet is located on the inner wall of the cylindrical outer shell. The ceramic heat storage structure carrier is hollow, encircling the outer periphery of the cylindrical combustion chamber, and its inner ring has a first heat inlet communicating with the first heat outlet. The ceramic heat storage structure carrier has an air passage for the exhaust gas to pass through. The combustion chamber is a cylindrical combustion chamber; the ceramic heat storage structure carrier is a ceramic heat storage ring plate composed of several ceramic heat storage blocks arranged in a ring at intervals, each of the ceramic heat storage blocks is a hollow structure block, and the inner ring of each of the ceramic heat storage blocks is provided with the first heat inlet hole, which is a protruding venting channel, and the length of the channel satisfies L1=πR. 2' / 12, R 2' The radius of the inner fan ring of the ceramic heat storage block; The first heat outlet hole on the cylindrical combustion chamber is arranged in a one-to-one correspondence with the ceramic heat storage block; the interval between any two adjacent ceramic heat storage blocks in the ceramic heat storage ring plate constitutes the air passage opening; the cylindrical combustion chamber has several protrusions on the inner wall of the area where the first heat outlet hole is located, so that the fluid exhibits the Coanda effect. The cylindrical combustion chamber is fitted with multiple sets of ceramic heat storage ring plates at intervals along its axial direction. Any two adjacent sets of ceramic heat storage ring plates are rotated and staggered. Along the direction from the exhaust gas inlet to the reaction product outlet, all odd-numbered ceramic heat storage ring plates are aligned, and all even-numbered ceramic heat storage ring plates are aligned.

2. The exhaust gas oxidation device according to claim 1, characterized in that, The inner wall of the columnar shell is provided with a ceramic heat storage layer structure, which can absorb and store the heat discharged by the thermal oxidation unit, so as to provide heat for the oxidation of methane when the thermal oxidation unit stops providing heat to the enclosed shell.

3. The exhaust gas oxidation device according to claim 2, characterized in that, The ceramic heat storage layer structure is a hollow ceramic heat storage brick. The inner wall of the ceramic heat storage brick is provided with a second heat inlet hole, and the outer ring of the ceramic heat storage structure carrier is provided with a second heat outlet hole that communicates with the second heat inlet hole.

4. The exhaust gas oxidation device according to claim 1, characterized in that, The outer wall of the enclosed shell is provided with a heat insulation structure.

5. A waste gas oxidation system, characterized in that, The device includes a waste heat recovery system, a pulverized coal recovery system, and a waste gas oxidation device as described in any one of claims 1 to 4. The pulverized coal inlet and the pulverized coal outlet are respectively located at opposite axial ends of the columnar combustion chamber. The ignition device is located within the columnar combustion chamber and at the same end as the pulverized coal inlet. A third heat outlet is also provided on the columnar combustion chamber, located at the same end as the pulverized coal outlet. The waste heat recovery system is connected to the third heat outlet to recover heat discharged from the columnar combustion chamber. The pulverized coal recovery system is connected to the pulverized coal outlet to recover pulverized coal discharged from the columnar combustion chamber.

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