A composite ammonia decomposition reactor and system

Abstract

The application discloses a composite ammonia decomposition reactor and system, which comprises a first reaction part and a second reaction part, and the first reaction part and the second reaction part are communicated; the first reaction part comprises a first pipeline and a second pipeline which are sleeved with each other, and the first sleeve and the second sleeve are communicated through a branch; the second reaction part comprises a spiral flue gas pipeline and a spiral mixed gas pipeline; the temperature of the gas flowing through the flue gas pipeline is greater than 600 DEG C; the flue gas pipeline is fixed around the second pipeline; the mixed gas pipeline is fixed around the second pipeline; the flue gas pipeline and the mixed gas pipeline are staggered; the mixed gas pipeline and the flue gas pipeline are attached to each other; the inlet end of the mixed gas pipeline is communicated with the outlet end of the first sleeve and the outlet end of the second sleeve. The composite ammonia decomposition reactor improves the heating effect of ammonia, so that the ammonia can be uniformly heated and decomposed, and the corrosion of ammonia on the reactor in the decomposition process is reduced, and the service life is improved.

Description

Technical Field

[0001] This invention relates to the field of clean energy equipment technology, specifically to a composite ammonia decomposition reactor and system that simultaneously incorporates a casing structure and a partition wall structure. Background Technology

[0002] Ammonia is not only an important inorganic chemical product, but it also has unique advantages as a hydrogen carrier. Ammonia is easily liquefied, has a pungent odor, is non-flammable and non-toxic at low concentrations, has high hydrogen storage density, and its production, storage, and transportation technologies are mature. Furthermore, hydrogen production is carbon-free, making it a highly efficient, clean, and safe hydrogen carrier. Producing hydrogen by decomposing ammonia is also a feasible and effective hydrogen production technology. The ammonia decomposition reactor is a crucial component in the ammonia decomposition process, used to decompose ammonia into hydrogen and nitrogen. Therefore, the structural design of the ammonia decomposition reactor has a significant impact on the ammonia decomposition efficiency and results. Existing ammonia decomposition reactors are typically large and complex in structure, with limited ammonia decomposition efficiency, strong dependence on catalysts, and the corrosive nature of ammonia. In an environment with long-term ammonia flow, the reactor structure will corrode, affecting equipment efficiency and service life.

[0003] Chinese patent CN115770524A discloses an ammonia cracker for an ammonia-hydrogen fuel power unit in automobiles, comprising a shell that runs vertically through the interior, an air inlet pipe on the upper cover, and an exhaust pipe on the lower cover. It also includes a ceramic electric heating plate with gas flow channels, a reaction plate containing an ammonia decomposition catalyst, and a through-hole pipe for gas heat exchange. The ceramic electric heating plates are symmetrically arranged below the upper cover and above the lower cover, with the reaction plate positioned between them. The through-hole pipe, the electric heating plates, and the reaction plate are interference-fitted. The ammonia is circulated and heated using both electric heating and high-temperature gas heat exchange to promote thermal decomposition and improve ammonia decomposition efficiency. However, the gas flow directions in this ammonia cracker are parallel, and the heating effect on the ammonia mainly relies on electric heating. It cannot effectively utilize the heat generated during ammonia decomposition, and the strong corrosiveness of ammonia can easily cause damage to the reactor exterior if the cracker is continuously circulated with ammonia. Summary of the Invention

[0004] To address the shortcomings of existing ammonia decomposition reactors, such as large size, complex structure, low ammonia decomposition and heating efficiency, high dependence on catalysts, and inability to be used in environments with long-term ammonia flow, a composite ammonia decomposition reactor and system is provided, which is compact, highly integrated, has excellent ammonia decomposition efficiency and heating effect, and can reduce damage caused by ammonia corrosiveness.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: A composite ammonia decomposition reactor, comprising a first reaction section and a second reaction section, the first reaction section and the second reaction section being connected. The first reaction section includes a first pipe and a second pipe, the second pipe being sleeved outside the first pipe, and the first pipe and the second pipe being connected by a branch. The second reaction section includes a spirally arranged flue gas pipe and a coiled mixed gas pipe. The temperature of the gas flowing in the flue gas pipe is greater than 600°C. The flue gas pipe and the second pipe are fixed around each other, and the mixed gas pipe is fixed around the second pipe. The flue gas pipe and the mixed gas pipe are arranged alternately, and the mixed gas pipe and the flue gas pipe are in close contact with each other. The inlet end of the mixed gas pipe is simultaneously connected to the outlet end of both the first pipe and the outlet end of the second pipe, and the outlet end of the mixed gas pipe and the inlet end of the first pipe are arranged facing the same side.

[0006] Furthermore, a heat exchange layer is fitted on the outer wall of the second pipe, covering the outer surface of the second pipe, and multiple heating devices are also installed on the heat exchange layer; the mixed gas pipe is fixed around the heat exchange layer; and the flue gas pipe is fixed around the heat exchange layer.

[0007] Furthermore, the heat exchange layer is made of stainless steel or graphite.

[0008] Furthermore, a guide plate is provided in the second pipe. The guide plate extends spirally along the extension direction of the second pipe toward the outlet pipe of the second pipe. The guide plate is fixed on the inner wall of the second pipe and is also connected to the outer wall of the first pipe.

[0009] Furthermore, the guide plate is coated with an ammonia decomposition catalyst, which is a ruthenium-based catalyst or a nickel-based catalyst.

[0010] Furthermore, the gas-mixing pipeline includes multiple baffles, a central baffle, and multiple diverting plates. The baffles are spaced apart, the central baffle is fixedly connected to the second pipeline, and the central baffle is also fixedly connected to multiple baffles. A diverting plate is provided between two adjacent baffles, one end of which is fixed to one of the baffles. The diverting plate extends towards the outlet end of the gas-mixing pipeline and passes through another adjacent baffle. Multiple diverting plates are respectively provided on both sides of the central baffle, and there is a gap between each diverting plate and the central baffle. At least two diversion holes are provided on each diverting plate, and the multiple diverting plates are interconnected through the diversion holes on each diverting plate and the gap between each diverting plate and the central baffle. Two adjacent baffles are also fixedly connected to a first surrounding plate, and the first surrounding plate is fixed to the outer edge of the two adjacent baffles respectively. The surface of one of the baffles is connected to the outlet end of the gas-mixing pipeline.

[0011] Furthermore, the flue gas duct includes a flue gas inlet, multiple flue gas channels, multiple flue gas baffles, and a flue gas outlet; the flue gas baffles are disposed between two adjacent baffles, and the flue gas baffles are fixedly connected to a guide plate and a central baffle located between two adjacent baffles; the edges of the flue gas baffles and adjacent baffles are fixedly connected to a second enclosure; the guide plate, central baffle, baffles, and adjacent flue gas baffles together form a flue gas flow channel; the flue gas flow channel and the mixed gas duct are fitted together but not connected; the flue gas inlet on the outer wall of the flue gas flow channel is connected to the gas channel, and the multiple flue gas flow channels are connected sequentially through the flue gas channels, with the outer wall of one of the flue gas flow channels connected to the flue gas outlet.

[0012] Furthermore, the cross-sectional shape of the baffle plate is circular, the cross-sectional shape of the flue gas baffle is circular, and the shape of the flue gas baffle corresponds to the shape of the baffle plate; the length of the mixed gas pipe is equal to the length of the flue gas pipe.

[0013] Furthermore, there are valves on the branch line used to adjust the flow rate of gas entering the branch line; the ammonia content in the branch line is 1-20% of the total ammonia flow.

[0014] This application also discloses an ammonia decomposition reaction system including a composite ammonia decomposition reactor, further comprising:

[0015] An ammonia supply system is connected to the inlet end of the first pipeline and is used to introduce ammonia into the first pipeline.

[0016] A heating gas supply system is connected to the inlet end of the flue gas duct and is used to introduce heating gas into the second reaction section.

[0017] A mixed gas collection device is connected to the outlet end of a mixed gas pipeline. The mixed gas collection device is used to collect the hydrogen-nitrogen mixed gas generated by heating and decomposing ammonia.

[0018] The present invention discloses a composite ammonia decomposition reactor and system. By connecting a first reaction section with a nested structure and a second reaction section with a spiral gas pipeline, heat from the second reaction section is transferred to the first reaction section during the reaction process. This ensures that the ammonia gas is fully and uniformly heated during flow, improving the heating and decomposition effects of the ammonia gas. Simultaneously, the first reaction section preheats and decomposes the ammonia gas, reducing the concentration of ammonia gas entering the second reaction section. This reduces corrosion caused by the introduced ammonia gas and extends the service life of the second reaction section. Furthermore, the use of a spiral gas pipeline to heat the mixed gas extends the flow distance of the mixed gas in the second reaction section, allowing for more thorough heating and decomposition of the ammonia gas, thus improving the overall integration and efficiency of the ammonia decomposition reactor. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a composite ammonia decomposition reactor according to the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of the first reaction section of a composite ammonia decomposition reactor according to the present invention;

[0022] Figure 3 This is a cross-sectional view of the first reaction section of a composite ammonia decomposition reactor according to the present invention;

[0023] Figure 4 This is a schematic diagram of the assembly of the first reaction section and the mixed gas pipeline of a composite ammonia decomposition reactor according to the present invention.

[0024] Figure 5 This is a schematic diagram of the assembly of the first reaction section and the mixed gas pipeline of the composite ammonia decomposition reactor according to the present invention from another angle.

[0025] Figure 6 This is a schematic diagram of the assembly of the first reaction section and the flue gas pipeline of a composite ammonia decomposition reactor according to the present invention. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0027] like Figures 1-6 As shown, the composite ammonia decomposition reactor of the present invention includes a first reaction section 1 and a second reaction section 2, wherein the first reaction section 1 and the second reaction section 2 are connected.

[0028] The first reaction section 1 includes a first pipe 11 and a second pipe 12, the second pipe 12 being sleeved outside the first pipe 11, and the first pipe 11 and the second pipe being connected by a branch 13.

[0029] The second reaction section 2 includes a spirally arranged flue gas duct 21 and a coiled mixed gas duct 22. The temperature of the gas flowing in the flue gas duct 21 is greater than 600°C. The flue gas duct 21 is fixed around the outer wall of the second pipe 12, and the mixed gas duct 22 is fixed around the outer wall of the second pipe 12. The flue gas duct 21 and the mixed gas duct 22 are arranged alternately, and the mixed gas duct and the flue gas duct 21 are fitted together. The inlet end of the mixed gas duct 22 is connected to both the outlet end of the first pipe 11 and the outlet end of the second pipe 12. The outlet end of the mixed gas duct 22 and the inlet end of the first pipe 11 face the same side.

[0030] This composite ammonia decomposition reactor connects a first reaction section with a nested structure and a second reaction section with a spiral structure for both flue gas and mixed gas pipelines. This allows some ammonia to be pre-heated and decomposed in the first reaction section, reducing the corrosive effect of the introduced ammonia on the second reaction section while ensuring the hydrogen content in the resulting gas. Furthermore, the spiral structure of the flue gas pipeline and the mixed gas pipeline in the second reaction section are staggered, extending the flow path of the mixed gas and ensuring that the heat from the gas in the flue gas pipeline is fully and completely transferred to the mixed gas. This allows the residual ammonia in the mixed gas to be further fully heated and decomposed, increasing the hydrogen content in the mixed gas and improving the integration of the composite ammonia decomposition reactor. It is suitable for ammonia decomposition applications with different volume requirements.

[0031] like Figure 1 and Figure 2As shown, the first reaction section 1 has a cylindrical structure, the shape of the first pipe 11 corresponds to the shape of the first reaction section 1, and the shape of the second pipe 12 corresponds to the shape of the first reaction section 1. The second pipe 12 is sleeved on the outside of the first pipe 11. Preferably, the first pipe 11 and the second pipe 12 are cylindrical, and the central axis of the first pipe 11 and the central axis of the second pipe 12 coincide. A branch 13 is provided on the first pipe 11, extending towards the outlet end of the first pipe 11, and one end of the branch 13 is flush with the wall of the first pipe 11. The other end of the branch 13 is connected to the second pipe 12. A valve 131 is provided on the branch 13 to control the gas flow rate in the branch 13. When the valve 131 is opened, some of the gas introduced into the first pipe 11 through the inlet end of the first pipe 11 can enter the branch 13 and then enter the second pipe 12. By adjusting the valve opening of the valve 131, the flow rate of the gas entering the branch 13 can be limited and adjusted, thereby adjusting the flow rate of the gas in the first pipe 11 and the branch 12. In order to improve the connection between the second reaction section 2 and the second pipe 12 and the first pipe 12, the branch 13 is connected to the second pipe 12. The heating effect between pipes 11 is specifically achieved by a heat exchange layer 14 fitted onto the outer wall of the second pipe 12. The shape of the heat exchange layer 14 corresponds to the shape of the second pipe 12, and the heat exchange layer 14 is cylindrical. The heat exchange layer 14 covers the outer surface of the second pipe 12, and multiple heating devices 15 are also provided on the heat exchange layer 14. More specifically, the heating devices 15 are electric heating devices. The multiple heating devices 15 are evenly arranged on the heat exchange layer 14 near the inlet end 110 of the first pipe. The installation direction of the heating devices 15 is parallel to the extension direction of the heat exchange layer 14. When the heating devices 15 are energized, the heating devices... The device 15 can heat the heat exchange layer 14, and the heat generated in the heat exchange layer 14 can be transferred to the ammonia gas located in the second pipe 12 and the first pipe 11, preheating the ammonia gas so that it decomposes to generate a mixed gas containing hydrogen and nitrogen. Specifically, the heat exchange layer 14 is made of graphite or stainless steel. At the same time, the outlet end 121 of the second pipe 12 is connected to the outlet end 111 of the first pipe 11, and the decomposed hydrogen and nitrogen gas discharged from the second pipe 12 can be mixed with the decomposed hydrogen and nitrogen gas discharged from the first pipe 11, and then enter the second reaction section 2. More specifically, an ammonia flow meter (not shown) is also provided on the branch 13, and the content of ammonia gas entering the branch 13 is 1-20% of the total amount of ammonia gas.More preferably, the heat exchange layer 14 is made of graphite, and the ammonia content in the branch 13 is 5-10% of the total ammonia content.

[0032] To better promote the heating of ammonia gas and ensure its full heating and decomposition within the second pipe 12, thereby improving decomposition efficiency and heating effect, a guide plate 122 is spirally arranged within the second pipe 12. The guide plate 122 extends spirally along the extension direction of the second pipe 12 towards the outlet end 121 of the second pipe 12. The guide plate 122 is fixed to the inner wall of the second pipe 12 and connected to the outer wall of the first pipe 11. When some ammonia gas is introduced into the second pipe 12 from the branch 13, it flows spirally towards the outlet end 121 of the second pipe 12 under the obstruction and guidance of the guide plate 122. Simultaneously, a bottom baffle 123 is provided at one end of the second pipe 12 relative to the inlet end 110 of the first pipe 11. Under the action of the bottom baffle 123, the heated gas is discharged through the outlet end 121 of the second pipe 12. Specifically, to better promote the heating of ammonia gas... The decomposition of ammonia reduces the concentration of ammonia in the mixed gas discharged from the first reaction section 1, allowing for more complete decomposition of ammonia. Preferably, the surface of the guide plate 122 is uniformly coated with an ammonia decomposition catalyst, such as a ruthenium-based catalyst or a nickel-based catalyst. When ammonia flows spirally in the second pipe 12, the combined action of the ammonia decomposition catalyst on the surface of the guide plate 122 and the heat exchange layer 14 electrically connected to the multiple heating devices 15 accelerates the thermal decomposition of ammonia, generating a mixed gas containing hydrogen and nitrogen. Simultaneously, a top baffle 124 is provided at the end of the second pipe 12 near the inlet end 110 of the first pipe 11. The top baffle 124 completely covers the end of the second pipe 12 near the inlet end 110 of the first pipe 11. The branch 13 passes through the top baffle 124 and connects to the second pipe 12, allowing the ammonia flowing out from the branch 13 to completely enter the second pipe 12, reducing ammonia loss during the flow process.

[0033] After the vaporized ammonia enters the first pipe 11 through the inlet end 110, the valve 131 on the branch 13 connected to the first pipe 11 is opened. A portion of the introduced ammonia enters the second pipe 12 connected to the branch 13. Under the action of the top baffle 124 on the second pipe 12 and the spirally arranged guide plate 122 inside the second pipe 12, the ammonia in the second pipe 12 spirals along the extension direction of the second pipe 12 towards the outlet end 111 of the first pipe 11. Blocked by the bottom baffle 123 at the bottom of the second pipe 12, the spirally flowing ammonia in the second pipe 12 passes through the second... The ammonia gas in the first pipe 11 flows directly along the extension direction of the first pipe 11 and is discharged through the outlet end 111 of the first pipe 11. Simultaneously, since the outer wall of the second pipe 12 is covered by the heat exchange layer 14, and multiple heating devices 15 are connected to the heat exchange layer 14, when ammonia gas enters the first pipe 11, the multiple heating devices 15 are activated to heat the heat exchange layer 14. The heat exchange layer 14 transfers the heated heat to the second pipe 12 connected to it and to the first pipe 11 located in the middle of the second pipe 12, thereby heating the ammonia gas in the second pipe 12 and the first pipe 11. The ammonia gas in the first pipe 11 undergoes a preliminary decomposition reaction upon heating, generating a mixture containing hydrogen, nitrogen, and a small amount of unreacted ammonia. Furthermore, the ammonia decomposition catalyst coated on the spirally arranged guide plate 122 in the second pipe 12 further promotes the ammonia decomposition reaction, improves the ammonia decomposition efficiency, and reduces the ammonia content and concentration in the mixed gas, thereby reducing the corrosive effect of ammonia on the subsequent second reaction section 2 and improving the overall service life. The mixed gas containing hydrogen, nitrogen, and unreacted ammonia, after preliminary decomposition, is discharged from the outlet 111 of the first pipe 11 and the outlet 121 of the second pipe 12, respectively, and then merges into the mixed gas pipeline 22 of the second reaction section 2. Since only 1-20% or even 5-10% of the ammonia gas flows from the first pipe 11 into the second pipe 12 through the branch 13, and the outer wall of the second pipe 12 is directly fixedly connected to the heat exchange layer 14, the ammonia gas flowing out of the second pipe 12 is fully decomposed under the action of the heat exchange layer 14 and the heating device 15, generating a mixed gas of hydrogen and nitrogen. This reduces the concentration of ammonia gas entering the second reaction section 2 after merging, while ensuring that the final mixed gas contains sufficient hydrogen and nitrogen. This reduces the corrosive effect of ammonia gas on the second reaction section, improves the service life of the second reaction section, and also ensures the production efficiency of the composite ammonia decomposition reactor.When the heat exchange layer 14 is made of graphite, graphite has good thermal conductivity and strength, as well as lubrication, which facilitates the separation between the first reaction section 1 and the second reaction section 2. When corrosion occurs in the first reaction section 1, it can be disassembled and replaced to reduce the impact on ammonia decomposition efficiency caused by corrosion of the first reaction section 1 due to long-term ammonia flow.

[0034] like Figures 4-5 As shown, the mixed gas pipeline 22 includes multiple baffles 221, a central baffle 222, and multiple diverting plates 223. The baffles 221 are spaced apart, with a gap between any two adjacent baffles 221. These gaps are interconnected. The installation direction of the baffles 221 is perpendicular to the installation direction of the second pipeline 12 of the first reaction section 1, and the baffles 221 are arranged parallel to each other. The central baffle 222 is fixedly connected to the second pipeline 12. Preferably, the extension direction of the central baffle 222 is parallel to the extension direction of the second pipeline 12, and the central baffle 222 is vertically fixed to the outer surface of the second pipeline 12. The central baffle 222 is simultaneously fixedly connected to the multiple baffles 221. A diverting plate 223 is provided between two adjacent baffles 221, and the diverting plate 223 is located on the side of the central baffle 222. The guide plate 223 is perpendicular to the baffle plate 221. The guide plate 223 is fixedly connected to two adjacent baffle plates 221. One end of the guide plate 223 is fixed to the surface of one of the baffle plates 221 and extends through the gap formed by the two adjacent baffle plates 221. The guide plate 223 passes through another adjacent baffle plate 221 and extends towards the outlet end 224 of the mixed gas pipeline into another adjacent gap. More specifically, multiple guide plates 223 are respectively arranged on the left and right sides of the central baffle 222. Adjacent guide plates 223 are arranged opposite each other. There is a gap between each guide plate 223 and the central baffle 222, which is used for gas flow between adjacent gaps. Preferably, the lengths of the multiple gaps formed by the two adjacent baffle plates 221 are equal. The guide plate 223 and the central baffle 221... 2 The gaps between them are equal; the cross-section of the barrier plate 221 is circular, and the barrier plate 221 closest to the outlet end 111 of the first pipe 11 has an opening 220, through which the first pipe 11 and the second pipe are connected to the gap formed by the two barrier plates 221 through the opening 220.

[0035] Furthermore, each of the diversion plates 223 is provided with a plurality of diversion holes 2231. At least one diversion hole 2231 communicates with the spacing through which the diversion plate 223 penetrates, and at least one diversion hole 2231 communicates with another adjacent spacing into which the diversion plate 223 extends. Adjacent diversion plates 223 are connected by at least two diversion holes 2231. In order to allow the gas to flow layer by layer between the gaps arranged side by side, a first surrounding plate 226 is provided between two adjacent barrier plates 221. The first surrounding plate 226 is fixedly connected to the outer edge of the two adjacent barrier plates 221 respectively. Next, the first enclosure 226 and the two adjacent barrier plates 221 together form a closed environment for gas flow and to prevent gas leakage during the flow process; the barrier plate 221 closest to the inlet end 110 of the first pipe 11 is provided with the outlet end 224 of the mixed gas pipe, and the outlet end 224 of the mixed gas pipe is connected to at least one of the drainage holes 2231 on one of the drainage plates 223. After further heating and decomposition, the mixed gas passes through the gaps between the multiple barrier plates 221 in sequence, and finally exits the mixed gas pipe 22 through the outlet end 224 of the mixed gas pipe.

[0036] After initial heating in the first reaction section 1, the mixed gas containing hydrogen, nitrogen, and unreacted ammonia is introduced through the opening 220 into the gap formed by the two baffle plates 221. Under the action of the first surrounding plate 226 and the central baffle 222, the mixed gas circulates in the gap to the side of the guide plate 223 on the other side of the central baffle 222. Since the guide plate 223 has at least one guide hole 2231 communicating with the gap through which the guide plate 223 penetrates, and there is a gap between the guide plate 223 and the central baffle 222 for gas to flow between the two gaps, the mixed gas flows through the guide hole 223 on the guide plate 223. 1. The gas enters the gap between the guide plate 223 and the central baffle 222, and then flows towards the outlet end 224 of the mixed gas pipeline to the next adjacent gap composed of two baffle plates 221. It is then discharged through the guide hole 2231 on the guide plate 223, which communicates with the gap into which the guide plate extends, and enters the adjacent gap. Under the action of the first enclosure plate 226 and the two baffle plates 221, the mixed gas circulates to the side of the other oppositely arranged guide plate 223, is discharged through the guide hole 2231 on that guide plate 223, and enters the next gap composed of two baffle plates 221. The gas mixture circulates within the gap between the two baffle plates 221 and continues to circulate towards the outlet end 224 of the gas mixture pipe, eventually exiting the gas mixture pipe 22 through the outlet end 224. Because the gas mixture circulates within the gap between the two baffle plates 221, and spirals between the baffle plates 221 through the multiple guide plates 223 and the guide holes 2231 on the guide plates 223, it finally exits through the outlet end 224 of the gas mixture pipe. Compared to traditional straight pipes, this significantly increases the flow distance of the gas mixture within the same volume. Due to the baffle plates 223... 21 is directly connected to the heat exchange layer 14 on the outer wall of the second pipe 12. When the mixed gas flows between the multiple baffles 221, the heat in the heat exchange layer 14 can be synchronously transferred to the mixed gas located in the multiple baffles 221. Since the mixed gas circulates along the mixed gas pipe 22, under the action of the heat exchange layer 14, the mixed gas is circulated and heated in the mixed gas pipe 22, so that the residual ammonia in the mixed gas can be fully and uniformly heated. At the same time, in order to better accelerate the decomposition efficiency of ammonia, the inside of the mixed gas pipe 22 can be filled with an ammonia decomposition catalyst, such as a ruthenium-based catalyst or a nickel-based catalyst.The gas mixing pipe 22 is internally provided with fins (not shown). Preferably, the fins are fixed to the surfaces of two baffle plates 221 that make up the gas mixing pipe 22. The fins on the two baffle plates 221 are arranged opposite to each other, thereby promoting the flow of gas in the gas mixing pipe 22 and reducing the thermal resistance of the gas in the gas mixing pipe 22. This allows heat to be transferred more effectively to the gas in the gas mixing pipe 22, improving the heating efficiency of the gas mixture.

[0037] like Figure 6 As shown, the flue gas duct 21 includes a flue gas inlet 210, multiple flue gas channels 211, multiple flue gas baffles 212, and a flue gas outlet 213. The flue gas baffles 212 are disposed between two adjacent baffles 221, and are fixedly connected to a guide plate 223 located between the two adjacent baffles 221 and a central baffle 222. The installation direction of the flue gas baffles 212 is parallel to the installation direction of the baffles 221. The flue gas baffles 212 divide the guide plate 223 into two parts, and one part of the guide plate 223 has at least one guide hole 2231. Another part of the diversion plate 223 is a closed section; the closed section of the diversion plate 223, the central baffle 222, the barrier plate 221, and the adjacent flue gas baffle 212 together form a flue gas flow channel for the flow of heated gas; multiple flue gas channels are arranged sequentially at intervals, wherein the flue gas flow channel closest to the outlet end 111 of the first pipe 11 is connected to the flue gas inlet 210 and the flue gas channel 211. More specifically, the flue gas inlet 210 and the flue gas channel 211 are respectively located on the side wall of the flue gas flow channel, and the flue gas inlet 210 is located at the... On the side of the central baffle 222, the flue gas passage 211 is located on the other side of the diversion plate 223. The flue gas inlet 210 and the flue gas passage 211 are arranged opposite to each other and are connected to each other. Similarly, a second enclosure plate 214 is provided between the flue gas baffle 212 and the adjacent barrier plate 221. The second enclosure plate 214 is fixedly connected to the edges of the flue gas baffle 212 and the barrier plate 221 respectively. The second enclosure plate 214, together with the connected barrier plate and the flue gas baffle 212, forms a sealing structure.

[0038] The flue gas passage 211 is a curved tubular structure, with both ends of the flue gas passage 211 communicating with the sidewalls of two flue gas channels spaced apart. Specifically, the sidewalls of the flue gas channels are simultaneously connected to the ports of both flue gas channels 211, which are symmetrically arranged. One port of the flue gas channel 211 is used to guide the heated gas from the adjacent flue gas channel into the flue gas channel connected to that port, while the other port of the flue gas channel 211 is used to discharge the heated gas after it has flowed through the flue gas channel and guide it into another flue gas channel connected to it. In adjacent flue gas passages; multiple flue gas passages 211 are sequentially connected to each other through multiple flue gas channels, so that the heating gas can flow spirally along the multiple flue gas passages 211 and multiple flue gas channels in sequence. Among them, the flue gas channel closest to the inlet end 110 of the first pipe 11 is connected to the flue gas outlet 213 to discharge the heated flue gas from the flue gas pipe 21, thereby completing the heating of the gas in the mixed gas pipe 22. More specifically, the temperature of the heating gas introduced into the flue gas pipe 21 is greater than 600°C, such as air or oxygen at 600-700°C.

[0039] To improve the heat exchange effect between the flue gas duct 21 and the mixed gas duct 22, increase the heat exchange area between the heating gas in the flue gas duct and the mixed gas in the mixed gas duct, and extend the flow distance of the mixed gas to accelerate the decomposition of residual ammonia in the mixed gas, preferably, the cross-sectional shape of the baffle plate 221 is circular, the cross-sectional shape of the flue gas baffle 212 is circular, and the shape of the flue gas baffle 212 corresponds to the shape of the baffle plate 221; the length of the mixed gas duct 22 is equal to the length of the flue gas duct 21.

[0040] When the mixed gas is discharged from the first pipe 11 and the second pipe 12 and enters the mixed gas pipe 22, and flows spirally along the mixed gas pipe 22, the heating gas for heating is introduced from the flue gas inlet 210 into the flue gas channel connected thereto. Under the action of the second baffle 214, the heating gas circulates in the flue gas channel and is discharged through another flue gas channel 211 connected to the flue gas channel, and then enters another adjacent flue gas channel through the flue gas channel; then the heating gas continues to circulate along the flue gas channel and is discharged into the next adjacent flue gas channel through another oppositely arranged flue gas channel 211; thus, it continuously spirals towards the direction of the flue gas outlet 213, and finally exits the flue gas pipe through the flue gas outlet 213; therefore, when the mixed gas flows spirally along the mixed gas pipe 22, the heating gas for heating the mixed gas also spirals along the flue gas pipe 21, and the heat of the heating gas itself is transferred to the mixed gas through the corresponding flue gas baffle 212, completing the further heating of the residual ammonia in the mixed gas, so that the mixed gas... The residual ammonia in the gas mixture can be further decomposed to generate hydrogen and nitrogen, reducing the ammonia content and concentration in the mixed gas while increasing the hydrogen content in the resulting gas. Similarly, since the flue gas pipe 21 and the mixed gas pipe 22 are spirally connected to the heat exchange layer 14 on the second pipe 12, when the heating gas used for heating circulates in the flue gas pipe 21, the temperature of the heating gas itself can be transferred to the ammonia located in the second pipe 12 and the first pipe 11 through the heat exchange layer 14, so as to better promote the thermal decomposition of ammonia in the first pipe 11. Since the mixed gas pipe 22 and the flue gas pipe 21 are staggered and in contact with each other, the mixed gas with a lower temperature and the heating gas with a higher temperature flow in opposite directions, which can increase the heat exchange area and heat exchange efficiency between the heating gas and the mixed gas. Similarly, the mixed gas pipe 22 and the flue gas pipe 21 are both spiral structures and are staggered. Under the same heating length, the spiral structure can reduce the overall equipment volume, thereby improving the integration of the composite ammonia decomposition reactor and making it suitable for more application scenarios.

[0041] This application also discloses an ammonia decomposition reaction system including the aforementioned composite ammonia decomposition reactor; further comprising:

[0042] An ammonia supply system is connected to the inlet end of the first pipeline, and the ammonia supply system is used to introduce ammonia into the first pipeline;

[0043] A heating gas supply system is connected to the inlet end of the flue gas duct and is used to introduce heating gas into the second reaction section.

[0044] A mixed gas collection device is connected to the outlet end of the mixed gas pipeline. The mixed gas collection device is used to collect the hydrogen-nitrogen mixed gas generated by heating and decomposing ammonia.

[0045] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A composite ammonia decomposition reactor, comprising a first reaction section and a second reaction section, wherein the first reaction section and the second reaction section are connected, characterized in that: The first reaction section includes a first pipe and a second pipe, the second pipe being sleeved outside the first pipe, and the first pipe and the second pipe being connected by a branch. The second reaction section includes a spirally arranged flue gas duct and a coiled mixed gas duct. The mixed gas duct includes multiple baffles, a central baffle, and multiple guide plates. The baffles are spaced apart. The central baffle is fixedly connected to the second duct and also fixedly connected to multiple baffles. A guide plate is arranged between two adjacent baffles. One end of the guide plate is fixed to one of the baffles. The guide plate extends towards the outlet end of the mixed gas duct and passes through the other adjacent baffle. The barrier plate; multiple diversion plates are respectively disposed on both sides of the central baffle, with a gap between each diversion plate and the central baffle; each diversion plate is provided with at least two diversion holes, and the multiple diversion plates are interconnected through the diversion holes on each diversion plate and the gap between each diversion plate and the central baffle; two adjacent barrier plates are also fixedly connected to a first enclosure plate, and the first enclosure plate is fixed to the outer edge of each of the two adjacent barrier plates; the surface of one of the barrier plates is connected to the outlet end of the mixed gas pipeline; The temperature of the gas flowing in the flue gas duct is greater than 600°C. The flue gas duct is fixedly connected to the second duct and the mixed gas duct is fixedly connected to the second duct. The flue gas duct and the mixed gas duct are arranged in an alternating manner and are in close contact with each other. The inlet end of the mixed gas duct is connected to both the outlet end of the first duct and the outlet end of the second duct. The outlet end of the mixed gas duct and the inlet end of the first duct face the same side. The branch is equipped with a valve for adjusting the flow rate of gas entering the branch; the ammonia content in the branch is 1-20% of the total ammonia flow.

2. The composite ammonia decomposition reactor according to claim 1, characterized in that: A heat exchange layer is fitted on the outer wall of the second pipe, the heat exchange layer covers the outer surface of the second pipe, and multiple heating devices are also provided on the heat exchange layer; The mixed gas duct is fixedly wrapped around the heat exchange layer; the flue gas duct is fixedly wrapped around the heat exchange layer.

3. The composite ammonia decomposition reactor according to claim 2, characterized in that: The heat exchange layer is made of stainless steel or graphite.

4. The composite ammonia decomposition reactor according to claim 1, characterized in that: A guide plate is provided in the second pipe. The guide plate extends spirally along the extension direction of the second pipe toward the outlet pipe of the second pipe. The guide plate is fixed on the inner wall of the second pipe and is also connected to the outer wall of the first pipe.

5. A composite ammonia decomposition reactor according to claim 4, characterized in that: The guide plate is coated with an ammonia decomposition catalyst, which is a ruthenium-based catalyst or a nickel-based catalyst.

6. The composite ammonia decomposition reactor according to claim 1, characterized in that: The flue gas duct includes a flue gas inlet, multiple flue gas channels, multiple flue gas baffles, and a flue gas outlet. The flue gas baffles are disposed between two adjacent baffles and are fixedly connected to a guide plate and a central baffle located between the two adjacent baffles. The edges of the flue gas baffles and the adjacent baffles are fixedly connected to a second enclosure. The guide plate, the central baffle, the baffles, and the adjacent flue gas baffles together form a flue gas flow channel. The flue gas flow channel and the mixed gas duct are fitted together but not connected. The outer wall of the flue gas flow channel communicates with the flue gas inlet and the flue gas channels. Multiple flue gas channels are sequentially connected through the flue gas channels, and the outer wall of one of the flue gas channels communicates with the flue gas outlet.

7. A composite ammonia decomposition reactor according to claim 6, characterized in that: The barrier plate has a circular cross-sectional shape, the flue gas baffle has a circular cross-sectional shape, and the shape of the flue gas baffle corresponds to the shape of the barrier plate; the length of the mixed gas pipe is equal to the length of the flue gas pipe.

8. An ammonia decomposition reaction system comprising the composite ammonia decomposition reactor according to any one of claims 1 to 7; characterized in that: Also includes: An ammonia supply system is connected to the inlet end of the first pipeline, and the ammonia supply system is used to introduce ammonia into the first pipeline; A heating gas supply system is connected to the inlet end of the flue gas duct and is used to introduce heating gas into the second reaction section. A mixed gas collection device is connected to the outlet end of the mixed gas pipeline. The mixed gas collection device is used to collect the hydrogen-nitrogen mixed gas generated by heating and decomposing ammonia.

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