A catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels

Abstract

The present invention relates to the technical field of ammonia combustion equipment, and specifically to a catalytic converter for low nitrogen oxide emissions of nitrogen-containing fuel. The catalytic converter for low nitrogen oxide emissions of nitrogen-containing fuel is provided with an ignition chamber consisting of a first ignition section and a second ignition section, and a first air inlet and a first catalyst are provided in the first ignition section, and a second air inlet and a second catalyst are provided in the second ignition section, so that a first mixed gas can be ignited in the first ignition section and a second mixed gas can be ignited in the second ignition section. Through the above-mentioned staged ignition and combustion, the catalytic converter for low nitrogen oxide emissions of nitrogen-containing fuel and the catalytic converter for low nitrogen oxide emissions of nitrogen-containing fuel with the catalytic converter for low nitrogen oxide emissions of nitrogen-containing fuel can effectively improve the ignition stability during ammonia combustion and avoid deflagration. At the same time, the nitrogen oxide emissions of the entire ammonia nitrogen-containing fuel low nitrogen oxide emission catalytic converter are reduced, thereby improving energy utilization.

Description

Technical Field

[0001] The present invention relates to the technical field of ammonia combustion equipment, and in particular to a catalytic converter for low nitrogen oxide emissions of nitrogen-containing fuel. Background Art

[0002] The primary combustion product of traditional fossil fuels is CO2, a major contributor to the greenhouse effect. In addition to CO2, large amounts of SO2 and metal oxides are also emitted, seriously polluting the environment. Therefore, finding a new energy source that can simultaneously avoid greenhouse gas emissions and other pollutants is of great significance to human society. In recent years, the scientific community has focused extensively on hydrogen. Although hydrogen offers high energy density, is pollution-free, and has a wide range of sources, its combustion is unstable and requires a liquefaction pressure of 10-15 MPa for transportation and storage. Therefore, its widespread application is difficult until the transportation and storage issues of hydrogen are resolved.

[0003] Ammonia, as a suitable H2 storage and conversion material, has a low liquefaction pressure of only 0.7-0.8 MPa at room temperature, making it easy to store and transport. It also has a high volumetric energy density. Under appropriate temperatures and oxygen concentrations, combustion products are only N2 and H20, resulting in zero carbon emissions, making it a promising alternative energy source. Compared to traditional energy sources, direct combustion of ammonia as a fuel has the following disadvantages: Its laminar combustion velocity and calorific value are relatively low, its ignition temperature is high, its combustion limit range is narrow, its stability is poor, and if not properly controlled, it can easily generate large amounts of nitrogen oxides (NOx), making its use difficult.

[0004] Therefore, at present, the application of ammonia fuel in internal combustion engines is mainly based on premixed ignition or dual-fuel combustion (such as diesel / ammonia dual fuel). This premixed ignition method has problems such as low combustion efficiency and poor combustion stability. The dual-fuel method still requires a large amount of diesel for ignition, so the effect of reducing carbon emissions is poor. Therefore, the existing ammonia-nitrogen-containing fuel low nitrogen oxide emission catalytic converters mostly focus on adjusting the ratio of ammonia to oxygen or air, or the treatment of exhaust gas after combustion. There are few studies on how to reduce nitrogen oxide emissions during the combustion stage and improve the low-temperature stable ignition performance of ammonia. Therefore, how to reduce nitrogen oxide emissions from existing ammonia-nitrogen-containing fuel low nitrogen oxide emission catalytic converters is a problem that urgently needs to be solved. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a catalytic converter for low nitrogen oxide emissions of nitrogen-containing fuels to solve the defects in the prior art.

[0006] In order to achieve the above technical effects, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels. The catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels can effectively improve the ignition stability during ammonia combustion and avoid deflagration, thereby reducing nitrogen oxide emissions from existing catalytic converters for low nitrogen oxide emissions from ammonia nitrogen-containing fuels. Specifically, the catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels includes:

[0008] an ignition chamber, the ignition chamber comprising a first ignition section and a second ignition section;

[0009] a first air inlet, connected to the first ignition section and used for inputting a first mixed gas into the ignition chamber;

[0010] a plurality of second air inlets, connected to the second ignition section and used for inputting a second mixed gas into the ignition chamber;

[0011] The catalytic unit comprises a first catalyst and a second catalyst arranged in sequence, wherein the first catalyst is arranged in the first ignition section, and the second catalyst is arranged in the second ignition section;

[0012] The preheating unit is used to preheat the first mixed gas and / or the second mixed gas to increase the temperature of the first mixed gas and the second mixed gas.

[0013] Furthermore, the nitrogen-containing fuel low-NOx emission catalytic converter further includes an ignition device disposed between the first air inlet and the first catalyst to ignite the first mixture entering the ignition chamber through the first air inlet. Preferably, the ignition device is any one of an electric spark ignition device, an electric heating ignition device, or a plasma ionization ignition device.

[0014] Furthermore, when the nitrogen-containing fuel low nitrogen oxide emission catalytic converter is working, the intake temperature of the first mixture is greater than the intake temperature of the second mixture, so as to improve the ignition efficiency and reduce the initial combustion temperature. Specifically, the preheating unit includes a mixing heat exchanger, a secondary heat exchanger and a heat source input pipeline. The mixing heat exchanger is arranged upstream of the secondary heat exchanger. The heat source input pipeline includes a high-temperature gas input end and two high-temperature gas output ends. The high-temperature gas input end can be used for high-temperature gas input, and the two high-temperature gas output ends are respectively connected to the mixing heat exchanger and the secondary heat exchanger. When the high-temperature gas is transported to the mixing heat exchanger and the secondary heat exchanger, the gas flowing through the mixing heat exchanger and the secondary heat exchanger can be heated by heat exchange. Specifically, the mixing heat exchanger is used to mix the high-temperature gas and the combustible gas to form a second mixed gas, and simultaneously heat-exchange the second mixed gas to increase its temperature before it enters the ignition chamber. Furthermore, because the mixing heat exchanger mixes the high-temperature gas and the combustible gas, it ensures that the ammonia concentration of the second mixed gas is within an appropriate range, effectively avoiding deflagration and localized uneven ignition temperatures. After the second mixed gas is formed in the mixing heat exchanger, a portion of it undergoes a secondary temperature increase in the secondary heat exchanger to form the first mixed gas, which is then delivered to the first ignition stage to improve ignition efficiency.

[0015] Furthermore, to generate the second mixed gas, the mixing heat exchanger is further connected to a combustible gas input unit for inputting ammonia and a combustion-supporting gas into the mixing heat exchanger. Specifically, the combustible gas input unit includes an ammonia input pipeline and a combustion-supporting gas input pipeline, each of which is used to input ammonia and a combustion-supporting gas into the mixing heat exchanger, respectively. The combustion-supporting gas contains at least oxygen, and is preferably any one of oxygen, air, or a mixture of oxygen and nitrogen. In the mixing heat exchanger, the ammonia and combustion-supporting gas are mixed with the high-temperature gas delivered to the mixing heat exchanger via the heat source input pipeline to form the second mixed gas. It should be noted that in this mixing heat exchanger, the order in which the combustion-supporting gas, ammonia, and high-temperature gas are mixed is not particularly limited.

[0016] In this embodiment, in order to achieve the transportation of the second mixture and the generation of the first mixture, the nitrogen-containing fuel low nitrogen oxide emission catalytic converter also includes a first intake branch and a second intake branch through which the second mixture can flow. The intake end of the first intake branch can be used for the input of part of the second mixture, and the output end of the first intake branch is connected to the second intake port through a number of first air distribution pipes to transport the second mixture into the ignition chamber, and the intake end of the second intake branch can be used for the input of part of the second mixture, and the output end of the second intake branch is connected to the secondary heat exchanger to transport part of the second mixture to the secondary heat exchanger for heating again to form the first mixture, and the temperature of the first mixture is higher than that of the second mixture.

[0017] Furthermore, a stepped mounting surface is provided between the first ignition section and the second ignition section, wherein the stepped mounting surface is annular, and a plurality of second air intakes are evenly spaced along the stepped mounting surface to achieve uniform intake and combustion of the second mixture.

[0018] Furthermore, the first catalyst includes a first carrier skeleton and a catalyst loaded on the first carrier skeleton. The first carrier skeleton is honeycomb-shaped and has a plurality of catalytic channels parallel to the conveying direction of the first mixed gas formed therein. The setting of the catalytic channels enables the first mixed gas to fully contact the catalyst, thereby reducing the activation energy required for ammonia combustion and effectively improving the uniformity of ammonia combustion.

[0019] Furthermore, the second catalyst is arranged downstream of the first catalyst, and the second catalyst includes a second carrier skeleton and a catalyst loaded on the second carrier skeleton. The second carrier skeleton is a circular mesh structure or a circular ring structure, and the periphery of the second carrier skeleton is fixedly connected to the inner wall of the ignition chamber. This setting of the second carrier skeleton can improve the strength of the second catalyst, promote the gas flow on both sides of the second catalyst, and effectively improve the thermal stress resistance of the second catalyst.

[0020] Preferably, the above-mentioned nitrogen-containing fuel low nitrogen oxide emission catalytic converter includes an ignition zone and a main combustion zone located downstream of the ignition zone, the ignition chamber is formed in the ignition zone, and the inner diameter of the main combustion zone is not smaller than that of the ignition zone.

[0021] Preferably, multiple groups of air intake nozzles are provided in the main combustion zone, and the multiple groups of air intake nozzles are arranged in sequence along the axial direction of the main combustion zone. The air intake nozzles can allow the second mixed gas to enter the main combustion zone to improve the lateral uniformity of the temperature of the main combustion zone.

[0022] Furthermore, the nitrogen-containing fuel low nitrogen oxide emission catalytic converter device also includes a flue gas recovery pipeline, which includes at least one input end and one output end. The input end of the flue gas recovery pipeline is connected to the main combustion zone or is arranged downstream of the main combustion zone, and the output end of the flue gas recovery pipeline is connected to the preheating unit, so that the combustion exhaust gas generated by the nitrogen-containing fuel low nitrogen oxide emission catalytic converter device can be collected and transported to the preheating unit as high-temperature gas to achieve heating of the first mixed gas and the second mixed gas. This method can recover the heat in the combustion exhaust gas and improve energy utilization.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] First, the nitrogen-containing fuel low nitrogen oxide emission catalytic converter provided by the present invention is provided with an ignition chamber consisting of a first ignition section and a second ignition section, and a first air inlet and a first catalyst are provided in the first ignition section, and a second air inlet and a second catalyst are provided in the second ignition section, so that the first mixture can be ignited in the first ignition section, and the second mixture can be ignited in the second ignition section. Through the above-mentioned staged ignition method, and in combination with the catalysis of the first catalyst and the second catalyst, ammonia can be ignited in a relatively mild atmosphere and provide sufficient heat for the second mixture in the subsequent main combustion zone to complete the ignition process. This nitrogen-containing fuel low nitrogen oxide emission catalytic converter and the nitrogen-containing fuel low nitrogen oxide emission catalytic converter with the nitrogen-containing fuel low nitrogen oxide emission catalytic converter can effectively improve the ignition stability during ammonia combustion, avoid deflagration, and at the same time, promote the combustion reaction of ammonia, reduce the nitrogen oxide emissions of the entire ammonia nitrogen-containing fuel low nitrogen oxide emission catalytic converter, and improve energy utilization.

[0025] Secondly, the low nitrogen oxide emission catalytic converter for nitrogen-containing fuels provided by the present invention can effectively reduce the ammonia concentration and avoid deflagration by arranging multiple groups of air inlet nozzles along the main combustion zone, thereby improving the uniformity of combustion, making the temperature of the entire ignition zone and the main combustion zone uniform in the horizontal direction, reducing the thermal stress of each working component, and significantly extending the flame length to make the combustion more complete. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the overall structure of a catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels provided in Example 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of the partially enlarged structure of a low nitrogen oxide emission catalytic converter for nitrogen-containing fuels provided in Example 1 of the present invention at position A;

[0028] Figure 3This is a schematic diagram of the overall structure of a catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels provided in Example 2 of the present invention;

[0029] Figure 4 This is a schematic diagram of the overall structure of a catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels provided in Example 3 of the present invention;

[0030] The accompanying drawings are marked as follows: 10, ignition zone, 101, ignition device, 11, first ignition section, 111, first catalyst, 111a, catalytic channel, 12, second ignition section, 121, second catalyst, 20, main combustion zone, 21, air inlet nozzle, 30, mixing heat exchanger, 31, ammonia gas input pipeline, 32, combustion-supporting gas input pipeline, 33, gas chamber, 331, heat exchange coil, 332, high-temperature gas inlet pipe, 332 a, air distribution port, 333, first air inlet branch, 333a, first air distribution pipeline, 333b, second air distribution pipeline, 334, second air inlet branch, 40, secondary heat exchanger, 41, heat exchange coil, 50, flue gas recovery pipeline, 51, heat source input pipeline, 61, first flue gas recovery pipe, 62, first heat source input pipe, 63, second flue gas recovery pipe, 64, second heat source input pipe, 71, pump body, 72, valve body. DETAILED DESCRIPTION

[0031] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0032] Unless otherwise specified, in the present invention, if there are terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", "x direction", "y direction", "z direction", etc., indicating orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the orientation or positional relationship in the present invention are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, they can understand the specific meanings of the above terms in conjunction with the drawings and according to specific circumstances.

[0033] Example 1

[0034] See also Figures 1-2The present embodiment provides a catalytic converter device for low nitrogen oxide emissions from nitrogen-containing fuels, which includes an ignition zone 10 and a main combustion zone 20 located downstream of the ignition zone 10, and an ignition chamber is formed in the ignition zone 10, which specifically includes a first ignition section 11 and a second ignition section 12, the second ignition section 12 including a first end connected to the first ignition section 11 and a second end connected to the main combustion zone 20, the inner diameter of the first end is smaller than the second end so that the second ignition section 12 is in an expanded shape, the inner diameter of the main combustion zone 20 is equal to the inner diameter of the second end, and ignition of the catalytic converter device for low nitrogen oxide emissions from nitrogen-containing fuels occurs in the ignition chamber.

[0035] In this embodiment, in order to improve the ignition efficiency and make the temperature uniform in the longitudinal direction of the ignition chamber to avoid explosion, the ignition chamber is provided with a first air inlet and several second air inlets, the first air inlet is used to supply the first mixture and is located in the first ignition section 11, the second air inlet is used to supply the second mixture and is located in the second ignition section 12, wherein the first air inlet is arranged at the geometric center of the first ignition section 11, and a stepped mounting surface is provided between the first ignition section 11 and the second ignition section 12, the stepped mounting surface is in a circular ring shape, and several second air inlets are evenly arranged along the stepped mounting surface to achieve uniform intake of the second mixture.

[0036] In this embodiment, to avoid deflagration during the ignition phase and improve ignition stability, a first catalyst 111 and a second catalyst 121 are respectively provided within the first ignition section 11 and the second ignition section 12 to reduce the activation energy required for ammonia combustion, thereby achieving the technical effect of promoting combustion and, to a certain extent, reducing nitrogen oxide emissions. Specifically, to adapt to the combustion characteristics of ammonia, the first catalyst 111 is provided downstream of the first air inlet, and the second catalyst 121 is provided downstream of the first catalyst 111. The first catalyst 111 includes a first carrier skeleton and a catalyst supported on the first carrier skeleton. The first carrier skeleton is honeycomb-shaped and has a plurality of catalytic channels 111a formed therein, which are parallel to the direction of conveyance of the first mixed gas. The provision of the catalytic channels 111a allows the first mixed gas to fully contact the catalyst, thereby reducing the activation energy required for ammonia combustion and effectively improving the uniformity of ammonia combustion. The second catalyst 121 is located downstream of the first catalyst 111 and includes a second carrier skeleton and a catalyst supported on the second carrier skeleton. The second carrier skeleton has a circular mesh structure or an annular structure, and the periphery of the second carrier skeleton is fixedly connected to the inner wall of the ignition chamber. This second carrier skeleton configuration can increase the strength of the second catalyst 121, promote gas flow on both sides of the second catalyst 121, and effectively improve the thermal stress resistance of the second catalyst 121. The combination of the first catalyst 111 and the second catalyst 121 can effectively reduce the activation energy of ammonia combustion and the ignition temperature, and can also effectively improve the longitudinal temperature uniformity within the ignition chamber during the ignition phase, thereby improving ignition efficiency. It should be noted that the above-mentioned catalyst can be selected from catalysts for ammonia combustion in the prior art, such as a catalyst with cerium oxide as the main active ingredient.

[0037] In this embodiment, to improve ignition efficiency, the nitrogen-containing fuel low nitrogen oxide emission catalytic converter is further provided with a preheating unit. The preheating unit uses high-temperature gas as a heat source to achieve temperature increase of the first and second mixed gases. The high-temperature gas is generated by the combustion process of the nitrogen-containing fuel low nitrogen oxide emission catalytic converter, and is preferably the exhaust gas generated by the combustion process, so as to improve the energy utilization rate of the nitrogen-containing fuel low nitrogen oxide emission catalytic converter and reduce pollutant emissions. Specifically, when the nitrogen-containing fuel low nitrogen oxide emission catalytic converter is in operation, the intake temperature of the first mixed gas is higher than the intake temperature of the second mixed gas, so that the first mixed gas is easy to ignite in the first ignition section 11. The arrangement of the plurality of second air inlets can, on the one hand, maintain a low ammonia concentration at each ignition point in the ignition chamber to avoid deflagration. At the same time, since the temperature of the second mixed gas is lower than that of the first mixed gas, the second mixed gas and the first mixed gas are mixed and burned at the second air inlets, which can effectively reduce the initial combustion temperature so that the ammonia can be ignited in a relatively mild atmosphere and provide sufficient heat for the second mixed gas in the main combustion zone 20 to complete the ignition process.

[0038] In this embodiment, to increase the temperature of the first and second mixed gases, the nitrogen-containing fuel low-NOx emission catalytic converter is provided with a flue gas recovery pipeline 50. The preheating unit includes a mixing heat exchanger 30, a secondary heat exchanger 40, and a heat source input pipeline 51. The mixing heat exchanger 30 is located upstream of the secondary heat exchanger 40. Specifically, the flue gas recovery pipeline 50 includes at least one input end and one output end. The input end of the flue gas recovery pipeline 50 is located downstream of the primary combustion zone 20 to collect exhaust gas generated by the nitrogen-containing fuel low-NOx emission catalytic converter, while the output end of the flue gas recovery pipeline 50 is connected to the heat source input pipeline 51 to use the exhaust gas as high-temperature gas. More specifically, the heat source input pipeline 51 includes two high-temperature gas output ends, which are respectively connected to the mixing heat exchanger 30 and the secondary heat exchanger 40. After the high-temperature gas is delivered to the mixing heat exchanger 30 and the secondary heat exchanger 40, it can heat the gas flowing through the mixing heat exchanger 30 and the secondary heat exchanger 40 through heat exchange. Specifically, the mixing heat exchanger 30 is used to mix the high-temperature gas and the combustible gas to form a second mixed gas, and simultaneously achieve a primary temperature increase of the second mixed gas through heat exchange, thereby increasing the intake temperature of the second mixed gas before it is input into the ignition chamber. At the same time, because the mixing heat exchanger 30 mixes the high-temperature gas and the combustible gas, the ammonia concentration of the second mixed gas is within an appropriate range after mixing, effectively avoiding deflagration and localized uneven ignition temperatures. After the second mixed gas is formed in the mixing heat exchanger 30, part of the second mixed gas is heated for the second time in the secondary heat exchanger 40 to form the first mixed gas and is transported to the first ignition section 11 to improve the ignition efficiency.

[0039] To achieve the generation and primary temperature increase of the second mixed gas in the mixing heat exchanger 30, this embodiment further provides a means for achieving the aforementioned technical effects. Specifically, a gas chamber 33 is formed within the mixing heat exchanger 30, and the mixing heat exchanger 30 is further provided with a combustible gas input unit connected to the gas chamber 33. The combustible gas input unit includes an ammonia input pipeline 31 and a supporting gas input pipeline 32, which are respectively used to input ammonia and supporting gas into the mixing heat exchanger 30. Furthermore, a heat exchange coil 331 and a high-temperature gas inlet pipe 332 are also provided in the gas chamber 33. The heat exchange coil 331 has an input end and an output end. The input end of the heat exchange coil 331 is connected to the output end of the heat source input pipeline 51, while the output end is used to discharge the exhaust gas after heat exchange. The high-temperature gas inlet pipe 332 has an input end and a gas distribution end. The input end of the high-temperature gas inlet pipe 332 is connected to the output end of the heat source input pipeline 51. The gas distribution end of the high-temperature gas inlet pipe 332 is located within the gas chamber 33 and has multiple gas distribution ports 332a. The arrangement of the gas distribution ports 332a allows the high-temperature gas to enter the gas chamber 33 and mix with ammonia and supporting gas to form a second mixed gas. After dilution with the high-temperature gas, the ammonia concentration of the second mixed gas is reduced, thereby preventing deflagration. Preferably, the high-temperature gas inlet pipe 332 is located upstream of the heat exchange coil 331.

[0040] In this embodiment, in order to realize the transportation of the second mixture and the generation of the first mixture, the nitrogen-containing fuel low nitrogen oxide emission catalytic converter also includes a first intake branch 333 and a second intake branch 334 for the second mixture to flow therein, the intake end of the first intake branch 333 is connected to the mixing heat exchanger 30 and can be used for the input of part of the second mixture, the output end of the first intake branch 333 is connected to the second intake port through a number of first air distribution pipes 333a respectively, so as to transport the second mixture to the second ignition section 12 of the ignition chamber; the intake end of the second intake branch 334 is connected to the mixing heat exchanger 30 and can be used for the input of part of the second mixture, the output end of the second intake branch 334 is connected to the secondary heat exchanger 40 to transport part of the second mixture to the secondary heat exchanger 40 for secondary heating, thereby increasing its temperature and forming the first mixture, and the first mixture is transported to the first ignition section 11 through the first intake port for ignition.

[0041] In this embodiment, in order to heat the second mixed gas again in the secondary heat exchanger 40 , the secondary heat exchanger 40 may be implemented in the form of a heat exchange coil 41 , which is a prior art and will not be described in detail here.

[0042] In this embodiment, in order to achieve ignition of the first mixture, an ignition device 101 is provided between the first air inlet and the first catalyst 111. The ignition device 101 is an annular electric heater, which is arranged on the periphery of the first air inlet, thereby achieving uniform ignition of the first mixture in the first ignition section 11, and in the second ignition section 12, the complete combustion of the second mixture can be achieved by utilizing the propagation of the flame and the assistance of the catalyst.

[0043] In addition, in order to improve the uniformity of the lateral temperature in the main combustion zone 20, a plurality of groups of air intake nozzles 21 are provided in the main combustion zone 20, and the plurality of groups of air intake nozzles 21 are arranged in sequence along the axial direction of the main combustion zone 20. The air intake nozzles 21 are connected to the first air intake branch 333 through the second air distribution pipeline 333b, thereby allowing the second mixture to enter the main combustion zone 20, so that the staged combustion in the main combustion zone 20 can be achieved by controlling the air intake state of the air intake nozzle 21. This method can effectively reduce the damage of thermal stress to the low nitrogen oxide emission catalytic converter of nitrogen-containing fuel.

[0044] It should be noted that the low nitrogen oxide emission catalytic converter for nitrogen-containing fuel provided in this embodiment should also include a pump body 71 and a valve body 72 for controlling the flow rate of the gas flow. The above-mentioned pump body 71 and valve body 72 can be set as needed to achieve control of the ignition and combustion state of the low nitrogen oxide emission catalytic converter for nitrogen-containing fuel.

[0045] Example 2

[0046] See also Figure 3 This embodiment provides a catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels. The difference between this catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels and the catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels provided in Example 2 is that:

[0047] In this embodiment, in order to heat the second mixed gas again in the secondary heat exchanger 40 to form the first mixed gas, the heat source input pipeline 51 includes two high-temperature gas output ends, one of which is connected to the mixing heat exchanger 30, and the other is directly connected to the secondary heat exchanger 40, so that the high-temperature gas is directly transported to the second heat exchanger, and the high-temperature gas is directly mixed with the second mixed gas to further reduce the ammonia concentration of the second mixed gas and increase its temperature, thereby forming the first mixed gas.

[0048] Example 3

[0049] See also Figure 4This embodiment provides a catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels. The difference between this catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels and the catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels provided in Example 1 is that:

[0050] The heat source input pipeline 51 includes a first heat source input pipe 62 and a second heat source input pipe 64. The flue gas recovery pipeline 50 includes a first flue gas recovery pipe 61 and a second flue gas recovery pipe 63. The inlet end of the first flue gas recovery pipe 61 is located downstream of the primary combustion zone 20. The outlet end of the first flue gas recovery pipe 61 is connected to the first heat source input pipe 62 to reduce the ammonia concentration of the second mixed gas and prevent deflagration. The inlet end of the second flue gas recovery pipe 63 is directly connected to the primary combustion zone 20, and the outlet end of the second flue gas recovery pipe 63 is connected to the second heat source input pipe 64. This allows the high-temperature gas from the primary combustion zone 20 to be directly fed into the secondary heat exchanger 40, improving the heating efficiency of the secondary heat exchanger 40 and facilitating ignition of the first mixed gas.

[0051] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, and such modifications or equivalents shall be encompassed by the claims of the present invention. Any techniques, shapes, and structures not described in detail herein are well known.

Claims

1. A catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels, characterized in that: include: An ignition chamber, the ignition chamber comprising a first ignition section (11) and a second ignition section (12); a stepped mounting surface is provided between the first ignition section (11) and the second ignition section (12), the stepped mounting surface being annular, and a plurality of the second air inlets being evenly spaced along the stepped mounting surface; a first air inlet, connected to the first ignition section (11) and used for inputting a first mixed gas into the ignition chamber; a plurality of second air inlets, connected to the second ignition section (12) and used for inputting a second mixed gas into the ignition chamber; A catalytic unit comprises a first catalyst (111) and a second catalyst (121) arranged in sequence, wherein the first catalyst (111) is arranged in a first ignition section (11), and the second catalyst (121) is arranged in the second ignition section (12); A preheating unit, for preheating the first mixed gas and / or the second mixed gas; the preheating unit comprises a mixing heat exchanger (30), a secondary heat exchanger (40) and a heat source input pipeline (51); the heat source input pipeline (51) comprises a high-temperature gas input end and two high-temperature gas output ends, and the two high-temperature gas output ends are respectively connected to the mixing heat exchanger (30) and the secondary heat exchanger (40); the mixing heat exchanger (30) is used to achieve mixing of the high-temperature gas and the combustible gas to form a second mixed gas and simultaneously achieve a primary temperature increase of the second mixed gas; the second mixed gas portion is heated twice in the secondary heat exchanger (40) to form a first mixed gas and is transported to the first ignition section (11); The invention also includes a first air intake branch (333) and a second air intake branch (334) in which a second mixed gas can flow. The air intake end of the first air intake branch (333) can be used to input a portion of the second mixed gas. The output end of the first air intake branch (333) is connected to the second air intake port through a plurality of first air distribution pipes (333a). The air intake end of the second air intake branch (334) can be used to input a portion of the second mixed gas. The output end of the second air intake branch (334) is connected to the secondary heat exchanger (40).

2. The low nitrogen oxide emission catalytic converter for nitrogen-containing fuels according to claim 1, characterized in that: The mixing heat exchanger (30) is also connected to a combustible gas input unit, and the combustible gas is used to input ammonia and supporting gas into the mixing heat exchanger (30).

3. The low nitrogen oxide emission catalytic converter for nitrogen-containing fuels according to claim 1, characterized in that: The first catalyst (111) comprises a first carrier frame and a catalyst loaded on the first carrier frame. The first carrier frame is honeycomb-shaped and has a plurality of catalytic channels (111a) formed therein that are parallel to the first mixed gas conveying direction.

4. The low nitrogen oxide emission catalytic converter for nitrogen-containing fuels according to claim 1, characterized in that: The second catalyst (121) includes a second carrier skeleton and a catalyst loaded on the second carrier skeleton, the second carrier skeleton is in a circular mesh structure or an annular structure, and the periphery of the second carrier skeleton is fixedly connected to the inner wall of the ignition chamber.

5. The low nitrogen oxide emission catalytic converter for nitrogen-containing fuels according to claim 1, characterized in that: It comprises an ignition zone (10) and a main combustion zone (20), wherein the ignition chamber is formed in the ignition zone (10), and the inner diameter of the main combustion zone (20) is not smaller than that of the ignition zone (10).

6. A catalytic converter for low nitrogen oxide emissions from nitrogen-containing fuels according to claim 5, characterized in that: The nitrogen-containing fuel low nitrogen oxide emission catalytic converter further includes a flue gas recovery pipeline (50), the flue gas recovery pipeline (50) including at least one input end and one output end, the input end of the flue gas recovery pipeline (50) being connected to the main combustion zone (20) or being arranged downstream of the main combustion zone (20), and the output end of the flue gas recovery pipeline (50) being connected to the preheating unit.

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