Ammonia cracker with thermo-field coupling dynamically adjustable and control method thereof

Abstract

The present invention discloses an ammonia cracker with dynamically adjustable thermal field coupling and a control method, which includes an ammonia preheating device and an ammonia cracking reaction device. The ammonia preheating device includes a combustion preheating chamber and a controllable pure ammonia burner. The combustion preheating chamber includes a combustion chamber and an ammonia preheating chamber. The ammonia preheating chamber surrounds the outer periphery of the combustion chamber. The controllable pure ammonia burner includes an ammonia fuel nozzle and an air swirl assembly. The air swirl assembly includes a plurality of swirl fan blades, and the circumferential spacing between the plurality of swirl fan blades is adjustable. The ammonia cracking reaction device includes a tail gas inlet pipe, a mixed gas heat exchange chamber, and an ammonia cracking reaction tube. The ammonia cracking reaction tube is arranged in the mixed gas heat exchange chamber. The inlet of the mixed gas heat exchange chamber is simultaneously connected to the tail gas inlet pipe and the combustion chamber. The ammonia cracking reaction tube is connected to the ammonia preheating chamber, and an ammonia cracking catalyst is arranged inside the ammonia cracking reaction tube. The present invention realizes the requirements of high ammonia cracking rate and high energy utilization efficiency, and at the same time, the hydrogen production amount can be dynamically adjusted according to the hydrogen demand of the ammonia internal combustion engine.

Description

Technical Field

[0001] The present invention relates to the field of energy-saving and new energy vehicles, and particularly relates to an ammonia cracker with dynamically adjustable thermal field coupling and a control method therefor. Background Art

[0002] As a zero-carbon fuel, ammonia can be used in an ammonia internal combustion engine to drive a piston to do work. However, ammonia is difficult to ignite, so hydrogen needs to be supplied according to the hydrogen demand of the ammonia internal combustion engine under different working conditions. An on-vehicle ammonia cracking hydrogen production device can meet the on-line hydrogen production. However, ammonia cracking is a highly endothermic reaction, and the reaction temperature usually needs to reach about 450 °C to carry out efficient ammonia cracking. Therefore, a matching heat source needs to be supplied. Although the exhaust gas generated during the operation of the ammonia internal combustion engine is at 200 - 500 °C, it is not sufficient to stably support the efficient cracking of ammonia. Burning a part of ammonia to provide a heat source can generate ammonia combustion gas, which is a high-grade heat source for ammonia cracking. However, the temperature of the ammonia combustion gas generated by a traditional ammonia burner can usually reach 1300 °C, which is too high for ammonia cracking. In addition, the hydrogen demand of the ammonia internal combustion engine is different under different working conditions, so the amount of ammonia to be cracked is also different, and the heat required for ammonia preheating and ammonia cracking reactions is also different. At present, there is no effective solution for how to effectively couple and manage the thermal energy of the above-mentioned many variables so that the ammonia power system can match the energy required for preheating / reaction under any working condition. Summary of the Invention

[0003] The purpose of the present invention is to provide an ammonia cracker with dynamically adjustable thermal field coupling and a control method therefor, so as to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

[0004] The technical solution adopted to solve the above technical problems:

[0005] The present invention provides an ammonia cracker with dynamically adjustable thermal field coupling, comprising:

[0006] An ammonia preheating device, comprising a combustion preheating chamber and a controllable pure ammonia burner. The combustion preheating chamber includes a combustion chamber and an ammonia preheating chamber. The ammonia preheating chamber surrounds the outer periphery of the combustion chamber and has a partition heat exchange relationship with the combustion chamber. The controllable pure ammonia burner is coaxially installed at one end of the combustion chamber. A smoke exhaust port is provided at the other end of the combustion chamber. The controllable pure ammonia burner includes an ammonia fuel nozzle and an air swirl assembly arranged coaxially inside and outside. The air swirl assembly includes a plurality of swirl fan blades arranged at intervals in a ring shape on the outer peripheral side of the ammonia fuel nozzle. The plurality of swirl fan blades are inclined circumferentially, and the circumferential distance between the plurality of swirl fan blades is adjustable. An air swirl channel is formed between adjacent two swirl fan blades;

[0007] An ammonia cracking reaction device, comprising an exhaust gas inlet pipe, a mixed gas heat exchange chamber, and at least one ammonia cracking reaction tube. The ammonia cracking reaction tube is arranged in the mixed gas heat exchange chamber and has a wall heat exchange relationship with the mixed gas heat exchange chamber. The exhaust gas inlet pipe is used to collect the exhaust gas of an ammonia internal combustion engine. The inlet of the mixed gas heat exchange chamber is simultaneously communicated with the exhaust gas inlet pipe and the smoke outlet. The ammonia cracking reaction tube is communicated with the ammonia preheating chamber, and an ammonia cracking catalyst is arranged inside the ammonia cracking reaction tube.

[0008] The beneficial effects of the present invention are as follows:

[0009] During use, ammonia fuel is sprayed into the combustion chamber through an ammonia fuel nozzle, and air enters the combustion chamber in a swirling flow through an air swirling channel formed between the swirling fan blades, and mixes with the ammonia fuel to burn and generate a swirling flame and ammonia combustion gas. The flame is heated through the ammonia preheating chamber on the outer periphery of the combustion chamber. At the same time, ammonia is introduced into the ammonia preheating chamber, preheated and then enters the ammonia cracking reaction tube. The ammonia combustion gas is mixed with the exhaust gas of the ammonia internal combustion engine and then introduced into the mixed gas heat exchange chamber to heat the ammonia cracking reaction tube. For different hydrogen demand amounts, by adjusting the circumferential spacing between the swirling fan blades, specifically, a part of the swirling fan blades can be made to fit, and the other part of the swirling fan blades can be separated at a certain angle to control the strength of the swirling degree of the air in the combustion chamber, thereby controlling the heat transfer efficiency of the flame passing through the combustion chamber to the ammonia preheating chamber and the temperature of the ammonia combustion gas generated by ammonia combustion. In this way, according to the different hydrogen demand amounts of the ammonia internal combustion engine, different amounts of ammonia to be cracked can be preheated by matching heat. The ammonia combustion gas can further be mixed with the exhaust gas of the ammonia internal combustion engine to form a mixed gas and enter the mixed gas heat exchange chamber to heat the ammonia cracking reaction tube. The temperature of the mixed gas can also be adjusted by the air swirling assembly. In this way, the required amount of preheated ammonia can receive matching heat energy from the mixed gas in the ammonia cracking reaction tube, so as to achieve the purpose of highly efficient ammonia cracking to produce hydrogen. In summary, the ammonia cracker of the present invention can meet the requirements of high ammonia cracking rate and high energy utilization efficiency, and at the same time, the hydrogen production amount can be dynamically adjusted according to the hydrogen demand amount of the ammonia internal combustion engine.

[0010] As a further improvement of the above technical solution, the swirling fan blades include fixed swirling fan blades and adjustable swirling fan blades, and guide plates extending axially are connected to the windward ends of the fixed swirling fan blades and the adjustable swirling fan blades;

[0011] The controllable pure ammonia burner includes an ammonia fuel delivery pipe, a burner housing, and an air pipeline;

[0012] The air swirl assembly includes a stator air disk and a plurality of rotor air disks which are coaxially and relatively rotatably arranged at the end of the burner housing in sequence along the axial direction, the stator air disk is provided with a plurality of the fixed swirl blades at annular intervals, each of the rotor air disks is provided with a plurality of the adjustable swirl blades at annular intervals, the adjustable swirl blades are connected to the rotor air disk through the guide plate so that the fixed swirl blades and the adjustable swirl blades are located in the same plane in the axial direction, the ammonia fuel nozzle is arranged at the center of the stator air disk, the ammonia fuel delivery pipe penetrates into the burner housing and is connected to the ammonia fuel nozzle, and the air pipeline is communicated with the air swirl channel through the interior of the burner housing.

[0013] As a further improvement of the above technical solution, the stator wind disc comprises a center hole disc body, a stator outer ring spaced and sleeved on the outer periphery of the center hole disc body, a plurality of the fixed swirl blades are fixed between the center hole disc body and the stator outer ring, the center hole disc body is provided with at least two ignition electrode holes, a plurality of air holes, and an ammonia nozzle hole, the ammonia fuel nozzle is installed in the ammonia nozzle hole, the ignition electrode hole is provided with a high-energy ignition electrode, and the plurality of air holes are connected to the inside of the burner shell;

[0014] The rotor wind disk comprises a rotor inner ring and a rotor outer ring which are sleeved together with an inner and outer spacing, and the guide plate is connected between the rotor inner ring and the rotor outer ring.

[0015] As a further improvement of the above technical solution, the controllable pure ammonia burner further includes a plurality of driving mechanisms, and the plurality of driving mechanisms are respectively connected to the plurality of rotor wind discs in a transmission manner.

[0016] As a further improvement of the above technical solution, the thickness of the swirl blades is gradually increased from the inside to the outside in the radial direction;

[0017] An annular air-distributing plate is arranged inside the burner shell, and the air-distributing plate is arranged between the air pipeline and the air cyclone component.

[0018] As a further improvement of the above technical solution, an ammonia input pipeline is connected to one end of the ammonia preheating chamber near the smoke exhaust port, and an ammonia flow control valve is installed on the ammonia input pipeline. An ammonia output pipeline is connected to one end of the ammonia preheating chamber near the controllable pure ammonia burner, and the ammonia output pipeline is connected to the ammonia cracking reaction tube;

[0019] The combustion chamber comprises a cylindrical chamber wall body, which is a heat-conducting component. A plurality of fins are distributed at annular intervals on the outer peripheral surface of the chamber wall body, and the fins are axially extended and arranged in the ammonia preheating chamber.

[0020] As a further improvement of the above technical solution, the inlet of the mixed gas heat exchange chamber is connected with a mixing chamber, a baffle is arranged in the mixing chamber, and the smoke exhaust port and the outlet of the tail gas inlet pipe are respectively arranged on the mixing chamber on both sides of the baffle;

[0021] The outlet of the mixed gas heat exchange chamber is connected with a three-way catalytic device.

[0022] As a further improvement of the above technical solution, a plurality of ammonia cracking reaction tubes are evenly distributed at intervals in the mixed gas heat exchange chamber;

[0023] The mixed gas heat exchange chamber includes a heat exchange chamber heat preservation cover, and a plurality of baffle plates are arranged in the heat exchange chamber heat preservation cover in a staggered arrangement along the axial direction of the ammonia cracking reaction tubes to form a serpentine mixed gas flow path, and the ammonia cracking reaction tubes pass through the baffle plates.

[0024] As a further improvement of the above technical solution, one end of the heat exchange chamber heat preservation cover close to the outlet of the mixed gas heat exchange chamber is provided with an ammonia gas distribution chamber, the ammonia gas preheating chamber is communicated with the inlets of a plurality of ammonia cracking reaction tubes through the ammonia gas distribution chamber, and one end of the heat exchange chamber heat preservation cover close to the inlet of the mixed gas heat exchange chamber is provided with a cracked gas discharge pipe, and the cracked gas discharge pipe is communicated with the outlets of a plurality of ammonia cracking reaction tubes.

[0025] The present invention also provides a control method applicable to the ammonia cracker, including:

[0026] Obtaining the hydrogen demand of the ammonia internal combustion engine;

[0027] When the ammonia internal combustion engine is in a high hydrogen demand working condition, adjust the circumferential spacing between all the swirl fan blades to a first preset value, reduce the flow area of the air swirl channel between two adjacent swirl fan blades, so as to strengthen the swirl degree of the air in the combustion chamber, improve the heat transfer efficiency between the flame through the combustion chamber and the ammonia gas preheating chamber, and increase the ammonia gas amount introduced into the ammonia gas preheating chamber;

[0028] When the ammonia internal combustion engine is in a low hydrogen demand working condition, adjust the swirl fan blades to be closely attached to each other to expand the flow area of the air swirl channel, so as to weaken the swirl degree of the air in the combustion chamber, reduce the heat transfer efficiency between the flame through the combustion chamber and the ammonia gas preheating chamber, and reduce the ammonia gas amount introduced into the ammonia gas preheating chamber;

[0029] When the ammonia internal combustion engine is in a working condition between high hydrogen demand and low hydrogen demand, adjust some of the swirl fan blades to be closely attached to each other, and adjust the circumferential spacing between the other part of the swirl fan blades to a second preset value to control the ammonia gas amount introduced into the ammonia gas preheating chamber. Description of the Drawings

[0030] The following further describes the present invention in conjunction with the drawings and embodiments;

[0031] Figure 1 It is a schematic structural diagram of an ammonia cracker provided by the present invention in one embodiment;

[0032] Figure 2 It is a cross-sectional view of an ammonia cracker provided by the present invention in one embodiment;

[0033] Figure 3 It is a schematic structural diagram of a controllable pure ammonia burner provided by the present invention in one embodiment;

[0034] Figure 4 It is an exploded view of a controllable pure ammonia burner provided by the present invention in one embodiment;

[0035] Figure 5 It is a cross-sectional view of a controllable pure ammonia burner provided by the present invention in one embodiment;

[0036] Figure 6 It is a flowchart of a control method provided by the present invention in one embodiment;

[0037] Figure 7 It is a working schematic diagram of an ammonia cracker provided by the present invention in one embodiment under the high hydrogen demand condition of an ammonia internal combustion engine;

[0038] Figure 8 It is a working schematic diagram of an ammonia cracker provided by the present invention in one embodiment under the low hydrogen demand condition of an ammonia internal combustion engine;

[0039] Figure 9 It is a working schematic diagram of a controllable pure ammonia burner provided by the present invention in one embodiment under the high hydrogen demand condition of an ammonia internal combustion engine;

[0040] Figure 10 It is a working schematic diagram of a controllable pure ammonia burner provided by the present invention in one embodiment under the low hydrogen demand condition of an ammonia internal combustion engine;

[0041] Figure 11 It is a working schematic diagram of a controllable pure ammonia burner provided by the present invention in one embodiment under the relatively high hydrogen demand condition of an ammonia internal combustion engine

[0042] Figure 12 It is a working schematic diagram of a controllable pure ammonia burner provided by the present invention in one embodiment under the relatively low hydrogen demand condition of an ammonia internal combustion engine. Detailed Description of the Invention

[0043] This part will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The role of the drawings is to supplement the description in the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention. However, it should not be construed as a limitation on the protection scope of the present invention.

[0044] In the description of the present invention, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc., it is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0045] In the description of the present invention, if there are vocabulary descriptions such as "several", its meaning is one or more, and the meaning of multiple is more than two. Understanding such as greater than, less than, exceeding, etc. does not include the base number, and understanding such as above, below, within, etc. includes the base number.

[0046] In the description of the present invention, unless otherwise clearly defined, words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meaning of the above words in the present invention in combination with the specific content of the technical solution.

[0047] Referring to Figures 1 to 12 , the ammonia cracker with thermo-field coupling dynamically adjustable of the present invention includes an ammonia preheating device and an ammonia cracking reaction device.

[0048] As Figure 1 and Figure 2 shown, the ammonia preheating device of the embodiment of the present invention includes a combustion preheating chamber 2 and a controllable pure ammonia burner 1. Among them, the combustion preheating chamber 2 includes a combustion chamber 21 and an ammonia preheating chamber 22. In this embodiment, the combustion chamber 21 extends left and right. In other embodiments, the combustion chamber 21 can extend in other directions. The left end of the combustion chamber 21 is the smoke exhaust end, and the right end is the combustion end. A smoke exhaust port 213 is provided at the left end of the combustion chamber 21. The controllable pure ammonia burner 1 is installed at the right end of the combustion chamber 21, and the axis of the controllable pure ammonia burner 1 extends left and right. The controllable pure ammonia burner 1 is arranged to spray and burn towards the left.

[0049] The ammonia preheating chamber 22 surrounds the outer periphery of the combustion chamber 21, and the ammonia preheating chamber 22 has a wall heat exchange relationship with the combustion chamber 21. Specifically, the combustion chamber 21 includes a cylindrical wall body 211. The wall body 211 is a heat-conducting member, and heat exchange between the combustion chamber 21 and the ammonia preheating chamber 22 is realized through the wall body 211. In order to reduce heat loss, the outer wall of the ammonia preheating chamber 22 is a heat-insulating member.

[0050] The ammonia preheating chamber 22 of the embodiment of the present invention is connected with an ammonia input pipe 8 and an ammonia output pipe 222. When in use, ammonia enters the ammonia preheating chamber 22 from the ammonia input pipe 8, and the heat generated by the combustion of the controllable pure ammonia burner 1 preheats the ammonia in the ammonia preheating chamber 22 through the wall body 211, and the preheated ammonia is discharged from the ammonia output pipe 222.

[0051] As Figures 3 to 5 shown, the controllable pure ammonia burner 1 of this embodiment includes an ammonia fuel nozzle 14 and an air swirl assembly arranged coaxially inside and outside. The air swirl assembly includes a plurality of swirl fan blades arranged at an annular interval on the outer peripheral side of the ammonia fuel nozzle 14. The plurality of swirl fan blades are arranged obliquely in the circumferential direction, and the circumferential spacing between the plurality of swirl fan blades is adjustable, so that an air swirl channel is formed between adjacent two swirl fan blades.

[0052] As Figures 3 to 5 shown, the controllable pure ammonia burner 1 of the embodiment of the present invention includes an ammonia fuel delivery pipe 141, a burner housing 19 and an air pipeline 191. The air swirl assembly includes a stator air disc 11 and a plurality of rotor air discs 12. The stator air disc 11 and the plurality of rotor air discs 12 are coaxially and relatively rotatably arranged at the left end of the burner housing 19 in sequence from left to right along the axial direction. The air pipeline 191 is connected to the right end of the burner housing 19. The air pipeline 191 supplies air to the inside of the burner housing 19. The air flows from right to left in the burner housing 19 and then is sprayed into the combustion chamber 21 through the air swirl channel. The ammonia fuel nozzle 14 is arranged at the center of the stator air disc 11. The ammonia fuel delivery pipe 141 passes through the burner housing 19 from right to left and is connected to the ammonia fuel nozzle 14. The ammonia fuel delivery pipe 141 supplies combustion fuel to the ammonia fuel nozzle 14. This embodiment uses ammonia fuel. The ammonia fuel is sprayed into the combustion chamber 21 through the ammonia fuel nozzle 14 and mixed with air for combustion.

[0053] The swirl fan blades of the embodiment of the present invention are divided into fixed swirl fan blades 111 and adjustable swirl fan blades 121. The windward ends of the fixed swirl fan blades 111 and the adjustable swirl fan blades 121 are both connected with a guide plate 17 extending along the axial direction. The stator air disc 11 is annularly provided with a plurality of fixed swirl fan blades 111, and each rotor air disc 12 is annularly provided with a plurality of adjustable swirl fan blades 121. The adjustable swirl fan blades 121 are connected to the rotor air disc 12 through the guide plate 17. It can be understood that the axial connection positions of different rotor air discs 12 and the guide plate 17 are different, so that the fixed swirl fan blades 111 and the adjustable swirl fan blades 121 are both located in the same plane axially, and the air inlet flow path can be regularized between adjacent two guide plates 17, which helps to realize a uniform swirl field.

[0054] Furthermore, the stator air disk 11 includes a center hole disk body 112, a stator outer ring 113 spaced apart on the outer periphery of the center hole disk body 112, a plurality of fixed swirl blades 111 fixed between the outer peripheral wall of the center hole disk body 112 and the inner peripheral wall of the stator outer ring 113, and the center hole disk body 112 is provided with at least two ignition electrode holes 114, a plurality of air holes 115, and an ammonia nozzle hole 116, the ammonia fuel nozzle 14 is installed in the ammonia nozzle hole 116, the ignition electrode hole 114 is provided with a high-energy ignition electrode 117, and the plurality of air holes 115 are connected to the interior of the burner shell 19. In the embodiment of the present invention, combustion ignition is achieved through the high-energy ignition electrode 117, and the air volume near the ammonia fuel nozzle 14 is increased through the plurality of air holes 115 to improve the success rate of ignition.

[0055] The rotor fan disk 12 of the embodiment of the present invention includes a rotor inner ring 123 and a rotor outer ring 122 that are fitted together with each other at an inner and outer interval. The guide plate 17 at the upper end of the adjustable swirl blade 121 is connected between the rotor inner ring 123 and the rotor outer ring 122. The stator fan disk 11 of the present invention is fixed relative to the burner housing 19, and the rotor fan disk 12 is rotatable relative to the burner housing 19. It can be understood that the adjustable swirl blade 121 is rotatable relative to the fixed swirl blade 111. In this embodiment, a plurality of adjustable swirl blades 121 are attached to each fixed swirl blade 111.

[0056] The controllable pure ammonia burner 1 of the present invention also includes multiple driving mechanisms, which are respectively connected to the multiple rotor wind discs 12 in transmission. The embodiment of the present invention drives a rotor wind disc 12 to rotate separately through the driving mechanism. The driving mechanism includes a circumferential rack 13 fixedly mounted on the outer periphery of the rotor outer ring 122, a stepper motor 131 fixed on the burner housing 19, and a gear 132 connected to the stepper motor 131 in transmission. The gear 132 is meshed with the circumferential rack 13, and the gear 132 is driven to rotate by the stepper motor 131. When the gear 132 is meshed with the circumferential rack 13, the rotor wind disc 12 is driven to rotate, thereby realizing precise control of the position of the adjustable swirl blades 121 on the rotor wind disc 12, thereby precisely controlling the swirl intensity of the air in the combustion chamber 21.

[0057] Among them, the thickness of the swirl blades in the embodiment of the present invention is gradually increased from the inside to the outside in the radial direction. It can be understood that the blade tip of the swirl blade is wider than the blade root, so that the swirl blades on the stator wind disk 11 and the rotor wind disks 12 at each stage can be tightly fitted without gaps, avoiding air turbulence.

[0058] At the same time, if Figure 5 As shown, an annular air uniforming plate 15 is arranged inside the burner housing 19. The air uniforming plate 15 is arranged between the air pipeline 191 and the air swirl component. The air uniforming plate 15 can also regularize the air intake flow path, which helps to achieve a uniform swirl field.

[0059] Furthermore, the ammonia input pipe 8 of this embodiment is connected to one end of the ammonia preheating chamber 22 close to the exhaust port 213, while the ammonia output pipe 222 is connected to one end of the ammonia preheating chamber 22 close to the controllable pure ammonia burner 1. This makes the flow direction of ammonia in the ammonia preheating chamber 22 opposite to the flame injection direction in the combustion chamber 21, forming convective heat transfer to improve the heat transfer efficiency.

[0060] An ammonia flow control valve 81 is installed on the ammonia input pipe 8 of the embodiment of the present invention to control the flow rate of the ammonia to be cracked to match the requirements of the ammonia internal combustion engine.

[0061] To further improve the heat transfer effect, as Figure 2 shown, a plurality of fins 212 are annularly and spacedly distributed on the outer peripheral surface of the cavity wall body 211. The fins 212 extend axially in the ammonia preheating chamber 22. It can be understood that both the cavity wall body 211 and the fins 212 have a partition heat transfer relationship with the ammonia preheating chamber 22, which is beneficial to the efficient preheating of ammonia.

[0062] As Figure 2 shown, the ammonia cracking reaction device of the embodiment of the present invention includes an exhaust gas inlet pipe 5, a mixed gas heat exchange chamber 7, and at least one ammonia cracking reaction tube 3. The ammonia cracking reaction tube 3 extends left and right in the mixed gas heat exchange chamber 7. The ammonia cracking reaction tube 3 has a partition heat transfer relationship with the mixed gas heat exchange chamber 7. In some other embodiments, the ammonia cracking reaction tube 3 can extend in other directions. The exhaust gas inlet pipe 5 is used to collect the exhaust gas of the ammonia internal combustion engine. The inlet of the mixed gas heat exchange chamber 7 is simultaneously connected to the exhaust gas inlet pipe 5 and the exhaust port 213, and the ammonia cracking reaction tube 3 is connected to the ammonia preheating chamber 22. As Figure 7 and Figure 8 shown, an ammonia cracking catalyst 31 is provided inside the ammonia cracking reaction tube 3.

[0063] The ammonia preheated by the ammonia preheating chamber 22 enters the ammonia cracking reaction tube 3, while the ammonia combustion gas is mixed with the exhaust gas of the ammonia internal combustion engine and introduced into the mixed gas heat exchange chamber 7 to heat the ammonia cracking reaction tube 3.

[0064] During use, a part of the swirling fan blades can be made to fit together, while the other part of the swirling fan blades are separated at a certain angle, so as to control the strength of the swirling degree of the air in the combustion chamber 21, and further control the heat transfer efficiency of the flame passing through the combustion chamber 21 to the ammonia preheating chamber 22 and the temperature of the ammonia combustion gas generated by ammonia combustion. In this way, according to the different hydrogen demands of the ammonia internal combustion engine, different amounts of ammonia to be cracked can be preheated by the matching heat, and the ammonia combustion gas can be further mixed with the exhaust gas of the ammonia internal combustion engine to form a mixed gas, and enter the mixed gas heat exchange chamber 7 to heat the ammonia cracking reaction tube 3. Among them, the temperature of the mixed gas can also be adjusted by the air swirling assembly. In this way, the required amount of preheated ammonia in the ammonia cracking reaction tube 3 can receive the matching heat energy from the mixed gas, so as to achieve the purpose of efficient ammonia cracking to produce hydrogen.

[0065] In this embodiment, a plurality of ammonia cracking reaction tubes 3 are provided. The plurality of ammonia cracking reaction tubes 3 help to increase the heat exchange area and improve the heat exchange efficiency.

[0066] The mixed gas heat exchange chamber 7 of this embodiment includes a heat exchange chamber heat preservation cover 71. The mixed gas heat exchange chamber 7 is heat-preserved through the heat exchange chamber heat preservation cover 71 to reduce heat loss. Tube plates 73 are provided at both ends of the heat exchange chamber heat preservation cover 71. Both ends of the ammonia cracking reaction tube 3 are respectively fixed to the two tube plates 73, and a plurality of baffle plates 72 are arranged in a staggered manner along the axial direction of the ammonia cracking reaction tube 3 in the heat exchange chamber heat preservation cover 71 to form a serpentine mixed gas flow path. The ammonia cracking reaction tube 3 passes through the baffle plate 72, which helps to improve the heat exchange between the mixed gas and the ammonia cracking reaction tube 3.

[0067] The inlet of the mixed gas heat exchange chamber 7 is connected with a mixing chamber 6. A partition plate 61 is vertically arranged in the mixing chamber 6. The outlets of the exhaust gas inlet pipe 5 and the smoke outlet 213 are respectively arranged on the mixing chamber 6 on the left and right sides of the partition plate 61. The partition plate 61 can prevent the interference of the ammonia internal combustion engine exhaust gas flow on the ammonia combustion flame in the combustion chamber 21 and help the stable combustion of ammonia combustion.

[0068] The outlet of the mixed gas heat exchange chamber 7 is connected with a three-way catalytic device 9, which can realize the efficient treatment of the mixed gas.

[0069] One end of the heat exchange chamber heat preservation cover 71 of this embodiment close to the outlet of the mixed gas heat exchange chamber 7 is provided with an ammonia distribution chamber 223. The ammonia output pipeline 222 is communicated with the inlets of the plurality of ammonia cracking reaction tubes 3 through the ammonia distribution chamber 223. One end of the heat exchange chamber heat preservation cover 71 close to the inlet of the mixed gas heat exchange chamber 7 is provided with a cracked gas discharge pipeline 41. The cracked gas discharge pipeline 41 is communicated with the outlets of the plurality of ammonia cracking reaction tubes 3 through the cracked gas collecting chamber 4. In this way, the flow direction of the mixed gas in the heat exchange chamber heat preservation cover 71 and the ammonia in the ammonia cracking reaction tube 3 is set in the opposite direction to form convective heat exchange to improve the heat exchange efficiency.

[0070] Under different operating conditions, the ammonia internal combustion engine has different hydrogen requirements for its cylinders. At the same time, the exhaust gas temperature and flow rate of the ammonia internal combustion engine are also different under different operating conditions. For example, under conditions such as light load and low speed, the hydrogen requirement of the cylinder is low, and the exhaust gas temperature of the internal combustion engine is low and the flow rate is small; while under conditions such as heavy load and high speed, the hydrogen requirement of the cylinder is high, and the exhaust gas temperature of the internal combustion engine is high and the flow rate is large. According to the hydrogen requirement of the ammonia internal combustion engine and the exhaust gas temperature and flow rate, an embodiment of the present invention proposes a control method applicable to the ammonia cracker, such as Figure 6 shown, including the following steps:

[0071] Step S100: Obtain the hydrogen requirement of the ammonia internal combustion engine;

[0072] Step S200: When the ammonia internal combustion engine is in a high hydrogen requirement condition, adjust the circumferential spacing between all the swirl fan blades to a first preset value, reduce the flow area of the air swirl channel between two adjacent swirl fan blades, so as to strengthen the swirl degree of the air in the combustion chamber 21, improve the heat transfer efficiency between the flame passing through the combustion chamber 21 and the ammonia preheating chamber 22, and increase the amount of ammonia gas introduced into the ammonia preheating chamber 22;

[0073] Step S300: When the ammonia internal combustion engine is in a low hydrogen requirement condition, adjust the swirl fan blades to fit tightly, so as to expand the flow area of the air swirl channel, weaken the swirl degree of the air in the combustion chamber 21, reduce the heat transfer efficiency between the flame passing through the combustion chamber 21 and the ammonia preheating chamber 22, and reduce the amount of ammonia gas introduced into the ammonia preheating chamber 22;

[0074] Step S400: When the ammonia internal combustion engine is in a condition between high and low hydrogen requirements, adjust some of the swirl fan blades to fit tightly, and adjust the circumferential spacing between the other part of the swirl fan blades to a second preset value, and control the amount of ammonia gas introduced into the ammonia preheating chamber 22.

[0075] In step S200, that is, under conditions such as heavy load and high speed with high hydrogen requirements, such as Figure 7 shown, adjust the controllable pure ammonia burner 1, drive the multi-stage rotor air disk 12 to rotate, so that the adjustable swirl fan blades 121 of the multi-stage rotor air disk 12 and the fixed swirl fan blades 111 of the stator air disk 11 are separated at a certain angle. At this time, the shapes of the stator air disk 1111 and the rotor air disk 1212 are as Figure 9As shown in the figure; at this time, the flow space between adjacent swirl fan blades is small, increasing the blocking ability of air, resulting in an enhanced swirling degree of air in the combustion chamber 21; when ammonia fuel and air enter the combustion chamber 21 and are ignited, the length of the ammonia combustion flame is long and the flame shape is thick, thus enhancing the heat transfer efficiency of the ammonia combustion flame to the ammonia preheating chamber 22 through the chamber wall body 211 and the fins 212. However, the temperature of the ammonia combustion gas generated at this time is relatively low, about 1000 °C at the sixth temperature point; at this time, control the ammonia flow control valve 81 to introduce a relatively large amount of ammonia. A relatively large amount of ammonia can also be heated to about 400 °C at the second temperature point in the ammonia preheating chamber 22 with a relatively high heat transfer efficiency. After preheating, it enters each ammonia cracking reaction tube 3 through the ammonia distribution chamber 223; the relatively low-temperature ammonia combustion gas is mixed with the ammonia internal combustion engine exhaust gas with a high temperature (about 450 °C) and a large flow rate in the mixing chamber 6 to generate a mixed gas with a large flow rate, and the temperature of the mixed gas can still reach about 700 °C at the third temperature point; the mixed gas enters the mixed gas heat exchange chamber 7 and flows along the serpentine movement path formed by a plurality of staggered baffles 72 and the heat exchange chamber heat preservation cover 71 to heat the ammonia cracking reaction tubes 3; the ammonia cracking catalyst 31 in each ammonia cracking reaction tube 3 absorbs heat and can be maintained at about 450 °C at the fourth temperature point, and a large amount of ammonia is efficiently cracked into a large amount of cracked gas containing hydrogen and nitrogen under the high space velocity condition at this time. After the cracked gas enters the cracked gas collecting chamber 4, it is discharged through the cracked gas discharge pipe 41 for use in the ammonia internal combustion engine; after the large-flow mixed gas provides a large amount of reaction heat for heat exchange of the ammonia cracking reaction tubes 3, the remaining temperature drops to the fifth temperature point, but it is still above 250 °C and enters the three-way catalytic device 9 for efficient post-treatment of exhaust gas.

[0076] In step S300, that is, under working conditions with low hydrogen demand such as light load and low speed, such as Figure 8 As shown in the figure, adjust the controllable pure ammonia burner 1 to drive the multi-stage rotor wind disk 12 to rotate, so that the adjustable swirl fan blades 121 of the multi-stage rotor wind disk 12 are in contact with the fixed swirl fan blades 111 of the stator wind disk 11. At this time, the shapes of the stator wind disk 11 and the multi-stage rotor wind disk 12 are as shown in Figure 10As shown; at this time, the flow space between adjacent swirl fan blades is relatively large, reducing the ability to block air and resulting in a decrease in the swirl degree of air in the combustion chamber 21; when ammonia fuel and air enter the combustion chamber 21 and are ignited at this time, the length of the ammonia combustion flame is short and the flame shape is thin, thereby reducing the heat transfer efficiency of the ammonia combustion flame passing through the chamber wall body 211 and the fins 212 to the ammonia preheating chamber 22. However, the temperature of the ammonia combustion gas generated by ammonia combustion at this time is relatively high, reaching the first temperature point of 1300 °C; at this time, the ammonia flow control valve 81 is controlled to introduce a relatively small amount of ammonia. The relatively small amount of ammonia can also be heated to the second temperature point of about 400 °C in the ammonia preheating chamber 22 with relatively low heat transfer efficiency. After preheating, it enters each ammonia cracking reaction tube 3 through the ammonia distribution chamber 223; the relatively high-temperature ammonia combustion gas is mixed with the internal combustion engine exhaust gas with a low temperature (about 300 °C) and a small flow rate in the mixing chamber 6 to generate a mixed gas with a relatively low flow rate. The temperature of the mixed gas reaches the third temperature point of about 700 °C; the mixed gas enters the mixed gas heat exchange chamber 7 and flows along the serpentine movement path formed by the plurality of staggered baffles 72 and the heat exchange chamber heat preservation cover 71 to heat the ammonia cracking reaction tubes 3; the ammonia cracking catalyst 31 in each ammonia cracking reaction tube 3 absorbs heat and can be maintained at the fourth temperature point of about 450 °C, and efficiently cracks a small amount of ammonia into a small amount of cracked gas containing hydrogen and nitrogen under the low space velocity condition at this time. After the cracked gas enters the cracked gas collecting chamber 4, it is discharged through the cracked gas discharge pipe 41 for use in the ammonia internal combustion engine; after the small-flow mixed gas provides a certain amount of reaction heat for heat exchange of the ammonia cracking reaction tubes 3, the remaining temperature drops to the fifth temperature point, but is still above 250 °C, and enters the three-way catalytic device 9 for efficient post-treatment of the exhaust gas.

[0077] In step S400, that is, under other working conditions with different hydrogen demands, since the controllable pure ammonia burner 1 has a multi-stage rotor air disk 12, a part of the adjustable swirl fan blades 121 of the multi-stage rotor air disk 12 can be fitted with the fixed swirl fan blades 111 of the stator air disk 11, and another part of the adjustable swirl fan blades 121 of the multi-stage rotor air disk 12 are separated from the fixed swirl fan blades 111 of the stator air disk 11 at a certain angle, such as Figures 11 - 12As shown; in this way, the control of the strength of the swirling degree of the air in the combustion chamber 21 can be realized, and further the heat transfer efficiency of the flame to the ammonia preheating chamber 22 through the chamber wall body 211 and the fins 212 and the temperature of the ammonia combustion gas generated by ammonia combustion can be controlled; according to the different hydrogen demand of the ammonia internal combustion engine, the ammonia flow control valve 81 is controlled to introduce a matching amount of ammonia for preheating to the second temperature point of about 400 °C, and then enter each ammonia cracking reaction tube 3 through the ammonia distribution chamber 223; different ammonia combustion gases are mixed with the internal combustion engine exhaust gas at a matching temperature and flow rate in the mixing chamber 6, enter the mixed gas heat exchange chamber 7, and flow along the serpentine movement path formed by a plurality of staggered baffle plates 72 and the heat exchange chamber heat preservation cover 71, and heat the ammonia cracking reaction tube 3; the ammonia cracking catalyst 31 in each ammonia cracking reaction tube 3 absorbs heat and can be maintained at about 450 °C at the fourth temperature point, and efficiently cracks the required amount of ammonia into cracked gas containing hydrogen and nitrogen for use in the ammonia internal combustion engine; the remaining temperature of the mixed gas drops to the fifth temperature point, but still exceeds 250 °C, and enters the three-way catalytic device 9 for efficient post-treatment of the exhaust gas.

[0078] The above strategy can meet the requirements of high ammonia cracking rate and high energy utilization efficiency. At the same time, the hydrogen production amount can be dynamically adjusted according to the hydrogen demand of the ammonia internal combustion engine, and efficient post-treatment of the exhaust gas can also be realized.

[0079] The above specifically describes the preferred embodiments of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent variations or substitutions without departing from the spirit of the present invention, and these equivalent variations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A thermal field-coupled dynamically adjustable ammonia cracker, characterized in that include: An ammonia preheating device comprises a combustion preheating chamber and a controllable pure ammonia burner, wherein the combustion preheating chamber comprises a combustion chamber and an ammonia preheating chamber, wherein the ammonia preheating chamber surrounds the outer periphery of the combustion chamber and has a partition heat exchange relationship with the combustion chamber, wherein the controllable pure ammonia burner is coaxially installed at one end of the combustion chamber, wherein the other end of the combustion chamber is provided with a smoke exhaust port, wherein the controllable pure ammonia burner comprises an ammonia fuel nozzle and an air swirl assembly coaxially arranged inside and outside, wherein the air swirl assembly comprises a plurality of swirl blades arranged at annular intervals on the outer periphery of the ammonia fuel nozzle, wherein the plurality of swirl blades are arranged obliquely along the circumferential direction, wherein the spacing between the plurality of swirl blades along the circumferential direction is adjustable, and an air swirl channel is formed between two adjacent swirl blades; An ammonia cracking reaction device, comprising an exhaust gas intake pipe, a mixed gas heat exchange chamber and at least one ammonia cracking reaction tube, wherein the ammonia cracking reaction tube is arranged in the mixed gas heat exchange chamber and has a partition wall heat exchange relationship with the mixed gas heat exchange chamber, the exhaust gas intake pipe is used to collect the exhaust gas of an ammonia internal combustion engine, the inlet of the mixed gas heat exchange chamber is communicated with the exhaust gas intake pipe and the exhaust port at the same time, the ammonia cracking reaction tube is communicated with the ammonia preheating chamber, and an ammonia cracking catalyst is arranged inside the ammonia cracking reaction tube; The swirl blades include fixed swirl blades and adjustable swirl blades, and the windward ends of the fixed swirl blades and the adjustable swirl blades are both connected with guide plates extending in the axial direction; The controllable pure ammonia burner includes an ammonia fuel delivery pipe, a burner shell and an air pipeline; The air swirl assembly comprises a stator air disc and a plurality of rotor air discs which are coaxially and relatively rotatably arranged at the end of the burner housing in sequence along the axial direction, the stator air disc is provided with a plurality of the fixed swirl blades at annular intervals, each of the rotor air discs is provided with a plurality of the adjustable swirl blades at annular intervals, the adjustable swirl blades are connected to the rotor air disc through the guide plate, so that the fixed swirl blades and the adjustable swirl blades are both located in the same plane in the axial direction, the ammonia fuel nozzle is arranged at the center of the stator air disc, the ammonia fuel delivery pipe penetrates the burner housing and is connected to the ammonia fuel nozzle, and the air pipeline is communicated with the air swirl channel through the interior of the burner housing; The stator wind disk comprises a center hole disk body, a stator outer ring spaced and sleeved on the outer periphery of the center hole disk body, a plurality of fixed swirl blades are fixed between the center hole disk body and the stator outer ring, the center hole disk body is provided with at least two ignition electrode holes, a plurality of air holes, and an ammonia nozzle hole, the ammonia fuel nozzle is installed in the ammonia nozzle hole, the ignition electrode hole is provided with a high-energy ignition electrode, and the plurality of air holes are connected to the inside of the burner shell; The rotor wind disk comprises a rotor inner ring and a rotor outer ring which are sleeved together with an inner and outer spacing, and the guide plate is connected between the rotor inner ring and the rotor outer ring.

2. The ammonia cracker according to claim 1, characterized in that: The controllable pure ammonia burner also includes a plurality of driving mechanisms, and the plurality of driving mechanisms are respectively connected to the plurality of rotor wind discs in a driving manner.

3. The ammonia cracker according to claim 1, characterized in that: The thickness of the swirl fan blades is gradually increased from the inside to the outside along the radial direction; An annular air distribution plate is provided inside the burner housing, and the air distribution plate is arranged between the air pipeline and the air swirl assembly.

4. The ammonia cracker according to claim 1, wherein: One end of the ammonia preheating chamber close to the smoke exhaust port is connected with an ammonia input pipeline, and an ammonia flow control valve is installed on the ammonia input pipeline. One end of the ammonia preheating chamber close to the controllable pure ammonia burner is connected with an ammonia output pipeline, and the ammonia output pipeline is communicated with the ammonia cracking reaction tube; The combustion chamber includes a cylindrical chamber wall body, the chamber wall body is a heat-conducting member, and a plurality of fins are annularly and spacedly distributed on the outer peripheral surface of the chamber wall body, and the fins extend axially in the ammonia preheating chamber.

5. The ammonia cracker according to claim 1, wherein: The inlet of the mixed gas heat exchange chamber is connected with a mixing chamber, a partition plate is arranged in the mixing chamber, and the smoke exhaust port and the outlet of the tail gas inlet pipe are respectively arranged on the mixing chamber on both sides of the partition plate; The outlet of the mixed gas heat exchange chamber is connected with a three-way catalytic device.

6. The ammonia cracker according to claim 5, wherein: A plurality of the ammonia cracking reaction tubes are evenly distributed at intervals in the mixed gas heat exchange chamber; The mixed gas heat exchange chamber includes a heat exchange chamber heat preservation cover, and a plurality of baffle plates are arranged in the heat exchange chamber heat preservation cover in a staggered arrangement along the axial direction of the ammonia cracking reaction tube to form a serpentine mixed gas flow path, and the ammonia cracking reaction tube passes through the baffle plate.

7. The ammonia cracker according to claim 6, wherein: One end of the heat exchange chamber heat preservation cover close to the outlet of the mixed gas heat exchange chamber is provided with an ammonia distribution chamber, the ammonia preheating chamber is communicated with the inlets of a plurality of the ammonia cracking reaction tubes through the ammonia distribution chamber, and one end of the heat exchange chamber heat preservation cover close to the inlet of the mixed gas heat exchange chamber is provided with a cracked gas discharge pipeline, and the cracked gas discharge pipeline is communicated with the outlets of a plurality of the ammonia cracking reaction tubes.

8. A control method applicable to the ammonia cracker according to any one of claims 1 to 7, characterized in that, Including: Obtain the hydrogen demand of the ammonia internal combustion engine; When the ammonia internal combustion engine is in a high hydrogen demand working condition, adjust the circumferential spacing between all the swirl fan blades to a first preset value, reduce the flow area of the air swirl channel between two adjacent swirl fan blades, so as to strengthen the swirl degree of the air in the combustion chamber, improve the heat transfer efficiency between the combustion chamber and the ammonia preheating chamber, and increase the ammonia gas input into the ammonia preheating chamber; When the ammonia internal combustion engine is in a low hydrogen demand working condition, adjust the swirl fan blades to be closely attached to each other to expand the flow area of the air swirl channel, so as to weaken the swirl degree of the air in the combustion chamber, reduce the heat transfer efficiency between the combustion chamber and the ammonia preheating chamber, and reduce the ammonia gas input into the ammonia preheating chamber; When the ammonia internal combustion engine is in a working condition between high hydrogen demand and low hydrogen demand, adjust some of the swirl fan blades to be closely attached to each other, and adjust the circumferential spacing between the other part of the swirl fan blades to a second preset value to control the ammonia gas input into the ammonia preheating chamber.

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