Ammonia decomposition system and ammonia engine exhaust gas coupled heat supply control method

Abstract

The application relates to the technical field of ammonia decomposition, and discloses an ammonia decomposition system and an ammonia engine exhaust gas coupled heat supply control method, wherein the ammonia decomposition system comprises a heat supply module, a first shell and a feeding ignition combustion device, one side of the first shell is provided with a connecting pipe, a combustion chamber is arranged in the first shell, and the feeding ignition combustion device is connected to the outer side of the first shell corresponding to the combustion chamber; the ammonia decomposition module comprises a second shell and a decomposition pipe, a first partition plate and a second partition plate are arranged in the second shell, the first partition plate divides the second shell into a heat exchange cavity and an exhaust cavity, the second partition plate divides the upper part of the exhaust cavity into an air inlet cavity, the second shell is provided with an air inlet corresponding to the air inlet cavity, the second shell is provided with an air outlet corresponding to the exhaust cavity, and the second shell is provided with a heat supply pipe and a first exhaust pipe corresponding to the heat exchange cavity, the ammonia decomposition can utilize the exhaust gas of the ammonia engine to provide high-grade heat energy, and the overall heat exchange efficiency is high, and the working stability is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ammonia decomposition, and in particular to an ammonia decomposition system and an ammonia engine exhaust gas coupled heat supply control method. BACKGROUND

[0002] When the ammonia engine is running, since ammonia as the main fuel is not easy to ignite and has a slow laminar combustion speed, a part of hydrogen needs to be introduced into the cylinder to jet pilot the ammonia fuel, and the vehicle-mounted ammonia fuel is a high hydrogen carrier, which is suitable for manufacturing hydrogen through online ammonia cracking.

[0003] Most of the current ammonia decomposition technologies use electric heating, but the ammonia engine vehicle platform cannot provide a large amount of electric energy for a long time, and cannot directly use the electric heating mode. Some ammonia decomposition technologies use the heat energy contained in the ammonia engine exhaust gas, but the exhaust gas flow and temperature of the ammonia engine under different working conditions change significantly, resulting in large temperature fluctuations of the final exhaust gas, which is difficult to directly supply heat for ammonia decomposition. Therefore, there is an urgent need for a system that can use the ammonia engine exhaust gas to provide stable heat supply for ammonia decomposition. SUMMARY

[0004] The present application aims to provide an ammonia decomposition system and an ammonia engine exhaust gas coupled heat supply control method to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or create conditions.

[0005] The solution to the technical problem of the present application is:

[0006] An ammonia decomposition system comprises a heat supply module and an ammonia decomposition module. The heat supply module comprises a first shell and a feed ignition combustion device. One side of the first shell is provided with a connecting pipe. The first shell is provided with a combustion chamber. The feed ignition combustion device is connected to the outside of the corresponding combustion chamber of the first shell and can combust in the combustion chamber. The ammonia decomposition module comprises a second shell and a decomposition pipe. The second shell is provided with a first partition plate and a second partition plate. The first partition plate divides the second shell along the horizontal direction to form a heat exchange cavity and an exhaust cavity. The second partition plate divides the upper part of the exhaust cavity to form an intake cavity. The second shell is provided with an air inlet corresponding to the intake cavity. The second shell is provided with an air outlet corresponding to the exhaust cavity. The second shell is provided with a heat supply pipe and a first exhaust pipe corresponding to the heat exchange cavity. The heat supply pipe is connected to the first shell. The combustion chamber can exhaust to the heat supply pipe. One end of the decomposition pipe is connected to one side of the first partition plate close to the heat exchange cavity. The other end of the decomposition pipe is bent through the first partition plate and connected to one side of the second partition plate close to the exhaust cavity. The two ends of the decomposition pipe are respectively communicated with the intake cavity and the exhaust cavity.

[0007] The technical scheme has at least the following beneficial effects: the connecting pipe is used for connecting to the ammonia engine of the external device, the air inlet on the second shell is connected to the ammonia fuel input source of the external device, during operation, the gas generated by the ammonia engine during the working or exhaust stroke is discharged into the first shell through the connecting pipe, the feeding and ignition combustion device is combusted in the combustion chamber, so that the combustion chamber has a high temperature, at this time, the ammonia engine exhaust gas entering the first shell exchanges heat with the combustion chamber, improves the ammonia engine exhaust gas heat flux, and cools the combustion chamber, which is beneficial to the long-term stable operation of the combustion chamber, the heated ammonia engine exhaust gas enters the heat supply pipe, and mixes with the combustion gas discharged into the heat supply pipe after combustion in the combustion chamber, to form high-temperature mixed gas, and provide high-grade heat energy to the heat exchange cavity, the ammonia gas entering the air inlet flows into the decomposition pipe, passes through the exhaust cavity along the decomposition pipe, and then enters the heat exchange cavity to be heated and warmed up, the part of the decomposition pipe located in the heat exchange cavity can be filled with a catalyst, when the ammonia gas passes through the catalyst, hydrogen-nitrogen mixed gas is generated by the contact with the catalyst, and the hydrogen-nitrogen mixed gas flows out of the decomposition pipe and enters the exhaust cavity, at this time, the hydrogen-nitrogen mixed gas has a high temperature, and the part of the decomposition pipe located in the exhaust cavity can preheat the ammonia gas just entering the decomposition pipe, so that the ammonia gas can be warmed up to the required temperature in the heat exchange cavity, and the heat utilization rate is improved, and the temperature of the hydrogen-nitrogen mixed gas is reduced after the temperature is reduced, and the hydrogen-nitrogen mixed gas is discharged from the air outlet, so that the exhaust gas of the ammonia engine can provide high-grade heat energy for ammonia decomposition, and the overall heat exchange efficiency is high and the working stability is high.

[0008] As a further improvement of the above technical scheme, the heat supply pipe and the first exhaust pipe are arranged on the side of the second shell away from the exhaust cavity, a baffle is arranged on the inner side of the second shell at a position between the heat supply pipe and the first exhaust pipe, the baffle extends towards the first partition plate, the decomposition pipe is bent to pass through the baffle and then bent to pass through the first partition plate, and an airflow gap is formed between the baffle and the first partition plate. The baffle divides the interior of the second shell into a space for the tortuous flow of gas in the upward direction, and the high-temperature mixed gas entering the second shell from the heat supply pipe can directly heat and warm up the part of the decomposition pipe passing through the baffle upward, in actual application, the catalyst can be filled in the part of the decomposition pipe, so that the ammonia gas can reach a sufficient temperature during decomposition, the high-temperature mixed gas flows along the baffle to the first partition plate, and then flows downward into the space below the baffle through the airflow gap, at this time, the part of the decomposition pipe between the first partition plate and the baffle can be heated to heat and warm up the ammonia before contacting the catalyst, and finally discharged from the first exhaust pipe, so that the heat exchange efficiency of the high-temperature mixed gas and the decomposition pipe can be improved.

[0009] As a further improvement of the above technical solution, a plurality of spoilers are arranged on the top side of the baffle in a direction close to the first partition. When the high-temperature mixed gas flows along the baffle, it is blocked by the plurality of spoilers. The blocking of the high-temperature mixed gas by the spoilers can cause the high-temperature mixed gas to flow back, delay the heat exchange time of the high-temperature mixed gas in the heat exchange cavity, and strengthen the heating of the decomposition tube.

[0010] As a further improvement of the above technical solution, the first shell is connected with a second exhaust pipe, and a flow control valve is arranged on the second exhaust pipe. Part of the ammonia engine exhaust gas entering the first shell from the connecting pipe enters the heat supply pipe as the heat exchange medium for providing heat for ammonia decomposition, and part of the ammonia engine exhaust gas is discharged from the second exhaust pipe. In use, the amount of ammonia engine exhaust gas discharged from the second exhaust pipe can be controlled by the flow control valve, so as to adjust the temperature and flow of the high-temperature mixed gas in the heat supply pipe.

[0011] As a further improvement of the above technical solution, the first exhaust pipe is connected to the second exhaust pipe, and the position where the first exhaust pipe is connected to the second exhaust pipe is closer to the airflow end of the second exhaust pipe relative to the flow control valve. The connection of the first exhaust pipe to the second exhaust pipe can uniformly connect the exhaust gas of the first exhaust pipe and the second exhaust pipe to the same lower gas treatment module, improving the convenience of overall installation and use.

[0012] As a further improvement of the above technical solution, a plurality of baffles are arranged in the exhaust cavity, and two adjacent baffles in the exhaust cavity are staggered in the up-down direction. The hydrogen-nitrogen mixed gas discharged from the decomposition tube to the exhaust cavity can preheat and warm the ammonia gas just entering the decomposition tube, and the plurality of baffles staggered in the up-down direction can form a space in the exhaust cavity for guiding the gas to flow in a serpentine manner. This can prolong the flow distance and heat exchange time of the hydrogen-nitrogen mixed gas in the exhaust cavity, and improve the preheating effect of the ammonia gas in the decomposition tube.

[0013] As a further improvement of the above technical solution, a heat exchange gap is arranged between the outside of the combustion chamber and the inside of the first shell, the upper and lower ends of the combustion chamber extend to the inner top side and the inner bottom side of the first shell, respectively, a gas guide pipe is arranged on the top side of the first shell opposite the combustion chamber, and the gas guide pipe is connected to the heat supply pipe. When the feeding and ignition combustion device burns in the combustion chamber, heat is dissipated to the heat exchange gap between the combustion chamber and the first shell. At this time, the ammonia engine exhaust gas entering the first shell from the connecting pipe can flow around the combustion chamber, which can prolong the flow distance of the ammonia engine exhaust gas and improve the heat exchange effect with the combustion chamber, and better protect the combustion chamber from overheating. The exhaust gas after combustion in the combustion chamber enters the heat supply pipe from the gas guide pipe and mixes with the ammonia engine exhaust gas entering the heat supply pipe directly from the first shell.

[0014] The application discloses an ammonia engine exhaust gas coupled heat supply control method, which applies the ammonia decomposition system, and comprises the following steps.

[0015] Connecting the ammonia engine exhaust port to the connecting pipe and discharging the exhaust gas into the connecting pipe;

[0016] Supplying the ammonia fuel and air into the feeding ignition combustion device;

[0017] Controlling the heat flux in the heat supply pipe according to the flow of the ammonia fuel and air supplied into the feeding ignition combustion device.

[0018] The technical scheme has at least the following beneficial effects: when the ammonia engine exhaust gas is used for ammonia decomposition heat supply, the exhaust gas heat flux and flow are different under different working conditions such as cold start, low working condition idle speed and high speed large load, at this time, the heat flux in the heat supply pipe can be adjusted by controlling the flow of the ammonia fuel and air supplied into the feeding ignition combustion device, so that the ammonia decomposition module is stably supplied with heat.

[0019] As a further improvement of the above technical scheme, the control of the heat flux in the heat supply pipe according to the flow of the ammonia fuel and air supplied into the feeding ignition combustion device comprises the following steps.

[0020] Obtaining the flow and temperature of the gas in the connecting pipe, and recording as the exhaust gas heat flux;

[0021] Judging whether the exhaust gas heat flux is less than a preset target heat flux, and when the exhaust gas heat flux is less than the preset target heat flux, controlling to increase the flow of the ammonia fuel and air supplied into the feeding ignition combustion device.

[0022] As a further improvement of the above technical scheme, the control of the heat flux in the heat supply pipe according to the flow of the ammonia fuel and air supplied into the feeding ignition combustion device further comprises the following steps.

[0023] When the exhaust gas heat flux is not less than the preset target heat flux, controlling to decrease the flow of the ammonia fuel and air supplied into the feeding ignition combustion device. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical scheme in the embodiments of the application, the drawings needed in the embodiment description will be briefly described below. Obviously, the described drawings are only a part of the embodiments of the application, and not all the embodiments, and those skilled in the art can obtain other design schemes and drawings according to the drawings without creative labor.

[0025] Figure 1 It is a perspective view of the ammonia decomposition system of the application.

[0026] Figure 2It is the internal structure schematic diagram of the ammonia decomposition system of the present application.

[0027] Figure 3 It is Figure 2 A partial enlarged schematic view of part A.

[0028] In the drawings: 110-first shell, 120-feed ignition combustion device, 130-connection pipe, 140-combustion chamber, 150-heat exchange gap, 160-air guide pipe, 210-second shell, 211-first partition, 212-second partition, 213-heat exchange cavity, 214-exhaust cavity, 215-inlet cavity, 216-inlet, 217-outlet, 220-decomposition pipe, 230-heat supply pipe, 240-first exhaust pipe, 250-baffle, 251-damper, 260-second exhaust pipe, 261-flow control valve, 270-baffle, 310-ammonia fuel delivery pipe, 320-air delivery pipe, 330-high-energy ignition electrode, 340-air equalizing plate, 350-ammonia fuel nozzle, 360-air fan disc. DETAILED DESCRIPTION

[0029] The embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, for the purpose of explaining the present application, and should not be understood as a limitation of the present application.

[0030] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as a limitation of the present application, which does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0031] In the description of the present application, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If the first, second, etc. are described, they are only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of indicated technical features.

[0032] In the description of the present application, unless otherwise explicitly limited, the words such as setting, mounting, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0033] Referring to Figure 1 andFigure 2 An ammonia decomposition system comprises a heat supply module and an ammonia decomposition module, wherein the heat supply module comprises a first shell 110 and a feeding ignition combustion device 120, one side of the first shell 110 is provided with a connecting pipe 130, a combustion chamber 140 is arranged in the first shell 110, the feeding ignition combustion device 120 is connected to the outside of the first shell 110 corresponding to the combustion chamber 140, and the feeding ignition combustion device 120 can burn in the combustion chamber 140; the ammonia decomposition module comprises a second shell 210 and a decomposition pipe 220, a first partition plate 211 and a second partition plate 212 are arranged in the second shell 210, the first partition plate 211 separates the second shell 210 along the horizontal direction to form a heat exchange cavity 213 and an exhaust cavity 214, the second partition plate 212 separates the upper part of the exhaust cavity 214 to form an air inlet cavity 215, the second shell 210 is provided with an air inlet 216 corresponding to the position of the air inlet cavity 215, the second shell 210 is provided with an air outlet 217 corresponding to the position of the exhaust cavity 214, the second shell 210 is provided with a heat supply pipe 230 and a first exhaust pipe 240 corresponding to the position of the heat exchange cavity 213, the heat supply pipe 230 is connected to the first shell 110, the combustion chamber 140 can exhaust to the heat supply pipe 230, one end of the decomposition pipe 220 is connected to the side of the first partition plate 211 close to the heat exchange cavity 213, the other end of the decomposition pipe 220 is bent to pass through the first partition plate 211 and is connected to the side of the second partition plate 212 close to the exhaust cavity 214, the two ends of the decomposition pipe 220 are respectively communicated with the air inlet cavity 215 and the exhaust cavity 214, and in actual application, the number of the decomposition pipe 220 is multiple, so that the efficiency of ammonia decomposition is improved.

[0034] From the above, the connecting pipe 130 is used to access the ammonia engine of the external device, the air inlet 216 on the second shell 210 is connected to the ammonia fuel input source of the external device, and the feed ignition combustion device 120 is connected to the first shell 110. During operation, the gas generated by the ammonia engine during the working or exhaust stroke is discharged into the first shell 110 through the connecting pipe 130, and the feed ignition combustion device 120 burns in the combustion chamber 140, so that the combustion chamber 140 has a higher temperature. At this time, the ammonia engine exhaust gas entering the first shell 110 exchanges heat with the combustion chamber 140, improves the ammonia engine exhaust gas heat flux, and cools the combustion chamber 140, which is beneficial to the long-term stable operation of the combustion chamber 140. The heated ammonia engine exhaust gas enters the heat supply pipe 230 and mixes with the combustion gas discharged into the heat supply pipe 230 after combustion in the combustion chamber 140, forming high-temperature mixed gas to provide high-grade heat energy to the heat exchange cavity 213. The ammonia gas flowing into the air inlet 216 flows into the decomposition pipe 220, passes through the exhaust cavity 214 along the decomposition pipe 220, and then enters the heat exchange cavity 213 to be heated and warmed up. The part of the decomposition pipe 220 located in the heat exchange cavity 213 can be filled with a catalyst. When the ammonia gas passes through the catalyst, hydrogen-nitrogen mixed gas is generated by the contact with the catalyst. The hydrogen-nitrogen mixed gas flows out of the decomposition pipe 220 and enters the exhaust cavity 214. At this time, the hydrogen-nitrogen mixed gas has a high temperature, and the part of the decomposition pipe 220 located in the exhaust cavity 214 can preheat the ammonia gas entering the decomposition pipe 220, so as to ensure that the ammonia gas can be warmed up to the required temperature in the heat exchange cavity 213, improve the heat utilization rate, and reduce the temperature of the hydrogen-nitrogen mixed gas itself, which is discharged from the air outlet 217. In this way, the exhaust gas of the ammonia engine can be used to provide high-grade heat energy for ammonia decomposition, and the overall heat exchange efficiency is high and the working stability is strong.

[0035] As shown in Figure 3 The feed ignition combustion device 120 includes an ammonia fuel delivery pipe 310, an air delivery pipe 320, a high-energy ignition electrode 330, a uniform air plate 340, an ammonia fuel nozzle 350, and an air air disc 360. The ammonia fuel delivery pipe 310 is connected to the ammonia fuel nozzle 350, the ammonia combustion nozzle extends into the air delivery pipe 320, the air air disc 360 is connected to the top of the air delivery pipe 320, the ammonia combustion nozzle penetrates the air air disc 360 and extends into the combustion chamber 140, and the air delivery pipe 320 is provided with the uniform air plate 340 in the middle. In the feed ignition combustion device 120, the ammonia fuel is sprayed into the combustion chamber 140 through the ammonia fuel delivery pipe 310 and the ammonia fuel nozzle 350 after the flow rate is regulated, and the air is delivered by the air delivery pipe 320 after the flow rate is regulated, and then sprayed into the combustion chamber 140 by the air air disc 360 after passing through the uniform air plate 340. The ammonia fuel and the air are mixed at high speed in the combustion chamber 140, ignited by the ignition electrode, and produce ammonia combustion flame, which heats the combustion chamber 140 while the ammonia combustion exhaust gas is discharged into the heat supply pipe 230.

[0036] In order to improve the heat exchange effect of the high-temperature mixed gas and the decomposition tube 220, in the embodiment, the heat supply tube 230 and the first exhaust tube 240 are arranged on the side of the second shell 210 away from the exhaust cavity 214, a baffle 250 is arranged on the inner side of the second shell 210 between the heat supply tube 230 and the first exhaust tube 240, the baffle 250 extends towards the first partition plate 211, the decomposition tube 220 is bent to pass through the baffle 250 and then bent to pass through the first partition plate 211, and an airflow gap is formed between the baffle 250 and the first partition plate 211. The baffle 250 divides the interior of the second shell 210 into a space for the gas to flow in a zigzag manner in the up-down direction, the high-temperature mixed gas entering the second shell 210 from the heat supply tube 230 can directly heat the part of the decomposition tube 220 passing through the baffle 250 upwards, and in actual application, the catalyst can be loaded into the part of the decomposition tube 220, so that the ammonia gas can reach a sufficient temperature during decomposition, the high-temperature mixed gas flows along the baffle 250 to the first partition plate 211, and then enters the space below the baffle 250 from the airflow gap, at this time, the part of the decomposition tube 220 between the first partition plate 211 and the baffle 250 can be heated, so as to heat the ammonia before contacting the catalyst, and finally the ammonia is discharged from the first exhaust tube 240, thereby improving the heat exchange efficiency of the high-temperature mixed gas and the decomposition tube 220.

[0037] Further, a plurality of spoiler plates 251 are arranged on the top side of the baffle 250 in a direction close to the first partition plate 211, in actual application, the spoiler plates 251 on the top side of the baffle 250 extend upwards, and two spoiler plates 251 can also be connected on the side of the baffle 250 close to the first partition plate 211, and the two spoiler plates 251 extend in directions away from each other. When the high-temperature mixed gas flows along the baffle 250, the high-temperature mixed gas is blocked by the plurality of spoiler plates 251, and the blocking of the high-temperature mixed gas by the spoiler plates 251 can cause the high-temperature mixed gas to flow back, delay the heat exchange time of the high-temperature mixed gas in the heat exchange cavity 213, and strengthen the heating of the decomposition tube 220.

[0038] The decomposition tube 220 is bent multiple times in the second shell 210, starting from the part of the decomposition tube 220 connected to the first partition plate 211, the part of the decomposition tube 220 extending horizontally above the baffle 250 is a decomposition section, the part of the decomposition tube 220 bent downwards and passing through the baffle 250 is a temperature rising section, the part of the decomposition tube 220 extending horizontally below the baffle 250 is a heating section, and the part of the decomposition tube 220 passing through the first partition plate 211 and then bent upwards to be connected to the second partition plate 212 is a preheating section. The preheating section is preheated by the hydrogen-nitrogen mixed gas decomposed, the heating section, the temperature rising section and the decomposition section are mainly heated by the high-temperature mixed gas, and the catalyst such as ruthenium-based or cobalt-molybdenum-based catalyst is loaded into the decomposition section. In order to position the catalyst, supports or plugs can be loaded into the parts on both sides of the catalyst in the decomposition section, so as to maintain the stability of the catalyst.

[0039] In order to better regulate the heat flux in the heat supply pipe 230, the amount of ammonia engine exhaust gas used can be controlled, and therefore a structure for directly controlling the ammonia engine exhaust gas can be provided on the first shell 110. Specifically, the first shell 110 is connected to a second exhaust pipe 260, and the second exhaust pipe 260 is provided with a flow control valve 261. Part of the ammonia engine exhaust gas that enters the first shell 110 from the connecting pipe 130 enters the heat supply pipe 230 as a heat exchange medium that provides heat for ammonia decomposition, and part of the ammonia engine exhaust gas is discharged from the second exhaust pipe 260. In use, the amount of ammonia engine exhaust gas discharged from the second exhaust pipe 260 can be controlled by the flow control valve 261, thereby adjusting the temperature and flow of the high-temperature mixed gas in the heat supply pipe 230.

[0040] Further, the first exhaust pipe 240 is connected to the second exhaust pipe 260, and the position at which the first exhaust pipe 240 is connected to the second exhaust pipe 260 is closer to the airflow end of the second exhaust pipe 260 relative to the flow control valve 261. The connection of the first exhaust pipe 240 to the second exhaust pipe 260 allows the exhaust gas from the first exhaust pipe 240 and the second exhaust pipe 260 to be connected to the same lower gas treatment module, improving the convenience of overall installation and use.

[0041] In order to improve the efficiency of the generated hydrogen-nitrogen mixed gas in preheating the heat exchange in the exhaust cavity 214, in this embodiment, a plurality of baffles 270 are provided in the exhaust cavity 214. Adjacent two baffles 270 in the exhaust cavity 214 are staggered in the up-down direction, for example, the number of baffles 270 is two, and the two baffles 270 are connected to the two sides of the exhaust cavity 214, respectively. The hydrogen-nitrogen mixed gas discharged from the decomposition pipe 220 to the exhaust cavity 214 can preheat and warm the ammonia gas just entering the decomposition pipe 220, and the plurality of baffles 270 staggered in the up-down direction can form a space in the exhaust cavity 214 that guides the gas to flow in a serpentine manner. This can prolong the flow distance and heat exchange time of the hydrogen-nitrogen mixed gas in the exhaust cavity 214, and improve the preheating effect of the ammonia gas in the decomposition pipe 220.

[0042] The ammonia engine exhaust gas can only exchange heat with one side of the combustion chamber 140 after entering the first shell 110. In order to improve the heat exchange efficiency of the combustion chamber 140, the ammonia engine exhaust gas can flow around the outside of the entire combustion chamber 140 to achieve heat exchange. Specifically, a heat exchange gap 150 is arranged between the outside of the combustion chamber 140 and the inside of the first shell 110. The upper and lower ends of the combustion chamber 140 extend to the inner top side and the inner bottom side of the first shell 110, respectively. A gas guide pipe 160 is arranged on the top side of the first shell 110 opposite to the position of the combustion chamber 140, and the gas guide pipe 160 is connected to the heat supply pipe 230. When the feed ignition combustion device 120 burns in the combustion chamber 140, heat is dissipated to the heat exchange gap 150 between the combustion chamber 140 and the first shell 110. At this time, the ammonia engine exhaust gas entering the first shell 110 from the connecting pipe 130 can flow around the combustion chamber 140, which can not only prolong the flow path of the ammonia engine exhaust gas and improve the heat exchange effect with the combustion chamber 140, but also better protect the combustion chamber 140 from cooling. The exhaust gas after combustion in the combustion chamber 140 enters the heat supply pipe 230 from the gas guide pipe 160 and mixes with the ammonia engine exhaust gas directly entering the heat supply pipe 230 from the first shell 110.

[0043] An ammonia engine exhaust gas coupled heat supply control method, which applies the ammonia decomposition system described above, including but not limited to the following steps:

[0044] S100, connecting the ammonia engine exhaust port to the connecting pipe 130 and discharging exhaust gas into the connecting pipe 130;

[0045] S200, supplying ammonia fuel and air to the feed ignition combustion device 120;

[0046] S300, controlling the heat flux in the heat supply pipe 230 according to the flow rate of the ammonia fuel and air supplied to the feed ignition combustion device 120.

[0047] As can be seen from the above, when using ammonia engine exhaust gas to supply heat to ammonia decomposition, the exhaust gas heat flux and flow rate of the ammonia engine are different under different working conditions such as cold start, low-speed idle, high-speed heavy load, etc. At this time, the flow rate of the ammonia fuel and air supplied to the feed ignition combustion device 120 can be controlled to adjust the heat flux in the heat supply pipe 230, so as to stably supply heat to the ammonia decomposition module.

[0048] In step S300, the heat flux in the heat supply pipe 230 is controlled according to the flow rate of the ammonia fuel and air supplied to the feed ignition combustion device 120, including but not limited to the following steps:

[0049] Step S310, obtaining the gas flow temperature and flow rate in the connecting pipe 130, denoted as exhaust gas heat flux;

[0050] Step S320: Determine whether the exhaust heat flux is less than the preset target heat flux;

[0051] When the exhaust heat flux is less than the preset target heat flux, proceed to step S321, and control the increase of the supply of ammonia fuel and air to the feed ignition combustion device 120.

[0052] When the exhaust heat flux is not less than the preset target heat flux, proceed to step S322, and control the reduction of the supply of ammonia fuel and air to the feed ignition combustion device 120.

[0053] When the exhaust heat flux is less than the preset target heat flux, the heat energy provided by the ammonia engine exhaust is low, and it needs to be burned through the feed ignition combustion device 120 to obtain sufficient heat. Therefore, increasing the amount of ammonia fuel supplied to the feed ignition combustion device 120 can heat exchange and heat up the ammonia engine exhaust, thereby reaching the required ammonia decomposition heating temperature. When the exhaust heat flux is not less than the preset target heat flux, the heat energy provided by the ammonia engine exhaust is high, and it is not necessary for the feed ignition combustion device 120 to provide too much heat. At this time, controlling the reduction of the amount of ammonia fuel supplied to the feed ignition combustion device 120 can make the heat flux in the heating pipe 230 reach the ammonia decomposition heating temperature.

[0054] Further examples illustrate the above-mentioned exhaust gas coupled heating control method for ammonia engines:

[0055] When the ammonia engine is cold-started or idling at low operating conditions, the hydrogen required for jet ignition is temporarily supplied by an external hydrogen storage tank. At this time, the exhaust flow rate and temperature of the ammonia engine are detected to be low, approximately 100 kg / h and 100°C, respectively. A larger amount of ammonia fuel and air is then introduced into the feed ignition and combustion device 120, causing it to operate in the combustion chamber 140 and generate a larger amount of high-temperature ammonia combustion gas (flow rate 42 kg / h, temperature 1300°C). The ammonia engine exhaust flows through the outer wall of the combustion chamber 140 in the first housing 110, where it is cooled and protected, keeping the wall temperature below 800°C while simultaneously heating itself to 300°C. Subsequently, a portion of the ammonia engine exhaust (42 kg / h) is controlled to enter the external exhaust aftertreatment module via the second exhaust pipe 260, while another portion (58 kg / h) mixes with the exhaust from the combustion chamber 140 in the heating pipe 230, thereby increasing the total exhaust flow to the ammonia decomposition module to 100 kg / h at a temperature of 800°C. The decomposition pipe 220, after heat exchange within the second housing 210, begins to decompose ammonia into hydrogen, which is supplied to the ammonia engine and replenishes the external hydrogen storage tank. The exhaust gas from the ammonia engine, after heat exchange, is reduced to 400°C and enters the second exhaust pipe 260 from the first exhaust pipe 240 for exhaust gas mixing. After mixing, the temperature is maintained at 300°C and then enters the external exhaust gas after-treatment module for efficient after-treatment.

[0056] When the ammonia engine is running at high speed and high load, the exhaust flow rate and temperature are detected to be relatively high, approximately 1200 kg / h and 520°C, respectively. At this time, a small amount of ammonia fuel and air is introduced, causing the feed ignition combustion device 120 to operate in the combustion chamber 140, producing a small amount of high-temperature ammonia combustion gas (flow rate 33 kg / h, temperature 1300°C). The ammonia engine exhaust flows through the wall of the combustion chamber 140 in the first housing 110, where it is cooled and protected, keeping the wall temperature below 800°C while the exhaust itself is heated to 530°C. A portion of the ammonia engine exhaust (1150 kg / h) is then controlled to enter the exhaust aftertreatment module connection pipe 130 via the second exhaust pipe 260, while another portion (50 kg / h) mixes with the exhaust from the combustion chamber 140 in the heating pipe 230, resulting in a total exhaust flow to the ammonia decomposition module of 83 kg / h at a temperature of 900°C. The decomposition pipe 220, after heat exchange within the second housing 210, begins to decompose ammonia into hydrogen, which is supplied to the ammonia engine and replenishes the external hydrogen storage tank. After exhaust heat exchange, the temperature drops to 440°C and enters the second exhaust pipe 260 from the first exhaust pipe 240 for exhaust mixing. After mixing, the temperature is maintained at 500°C and then enters the exhaust after-treatment module for efficient after-treatment.

[0057] Under operating conditions between low idling and high-speed heavy load, the ammonia feed ignition and combustion device 120 module is coupled with different ammonia engine exhaust flow and temperature to provide the ammonia decomposition module with high-temperature exhaust with a flow rate between 83-100 kg / h and a temperature between 800-900℃. At the same time, the exhaust heat flux entering the exhaust gas after-treatment module is between 300-500℃ for efficient after-treatment.

[0058] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. An ammonia decomposition system, characterized in that: include: The heating module includes a first housing (110) and a feeding ignition combustion device (120). A connecting pipe (130) is provided on one side of the first housing (110). A combustion chamber (140) is provided inside the first housing (110). The feeding ignition combustion device (120) is connected to the outside of the combustion chamber (140) of the first housing (110). The feeding ignition combustion device (120) can burn in the combustion chamber (140). The ammonia decomposition module includes a second housing (210) and a decomposition tube (220). The second housing (210) is provided with a first partition (211) and a second partition (212). The first partition (211) horizontally divides the second housing (210) into a heat exchange chamber (213) and an exhaust chamber (214). The second partition (212) divides the area above the exhaust chamber (214) into an air inlet chamber (215). The second housing (210) has an air inlet (216) corresponding to the air inlet chamber (215) and an air outlet (217) corresponding to the exhaust chamber (214). (210) A heating pipe (230) and a first exhaust pipe (240) are provided at the position corresponding to the heat exchange chamber (213). The heating pipe (230) is connected to the first housing (110). The combustion chamber (140) can exhaust gas to the heating pipe (230). One end of the decomposition pipe (220) is connected to the side of the first partition (211) near the heat exchange chamber (213). The other end of the decomposition pipe (220) is bent through the first partition (211) and connected to the side of the second partition (212) near the exhaust chamber (214). The two ends of the decomposition pipe (220) are respectively connected to the air intake chamber (215) and the exhaust chamber (214).

2. The ammonia decomposition system according to claim 1, characterized in that: The heating pipe (230) and the first exhaust pipe (240) are disposed on the side of the second housing (210) away from the exhaust chamber (214). A baffle (250) is provided on the inner side of the second housing (210) between the heating pipe (230) and the first exhaust pipe (240). The baffle (250) extends toward the first partition (211). The decomposition pipe (220) bends through the baffle (250) and then bends through the first partition (211). An airflow gap is formed between the baffle (250) and the first partition (211).

3. The ammonia decomposition system according to claim 2, characterized in that: The baffle (250) has multiple baffles (251) spaced apart along the direction close to the first partition (211) on its top side.

4. An ammonia decomposition system according to claim 2, characterized in that: The first housing (110) is connected to a second exhaust pipe (260), and a flow control valve (261) is provided on the second exhaust pipe (260).

5. An ammonia decomposition system according to claim 4, characterized in that: The first exhaust pipe (240) is connected to the second exhaust pipe (260), and the position of the first exhaust pipe (240) connected to the second exhaust pipe (260) is closer to the airflow end of the second exhaust pipe (260) relative to the flow control valve (261).

6. An ammonia decomposition system according to claim 1, characterized in that: The exhaust chamber (214) is provided with a plurality of baffles (270), and two adjacent baffles (270) are staggered from each other in the vertical direction.

7. An ammonia decomposition system according to claim 1, characterized in that: A heat exchange gap (150) is provided between the outer side of the combustion chamber (140) and the inner side of the first shell (110). The upper and lower ends of the combustion chamber (140) extend to the inner top and inner bottom sides of the first shell (110), respectively. A gas guide pipe (160) is provided on the top side of the first shell (110) directly opposite the combustion chamber (140). The gas guide pipe (160) is connected to the heating pipe (230).

8. A method for controlling exhaust gas coupled with heating in an ammonia engine, characterized in that: The ammonia decomposition system according to any one of claims 1 to 7 comprises: Connect the exhaust port of the ammonia engine to the connecting pipe (130) and exhaust into the connecting pipe (130); Ammonia fuel and air are supplied to the feed ignition and combustion device (120); The heat flux in the heating pipe (230) is controlled according to the flow rate of ammonia fuel and air supplied to the feed ignition combustion device (120).

9. The exhaust gas coupling heating control method for an ammonia engine according to claim 8, characterized in that: The control of the heat flux in the heating pipe (230) based on the flow rate of ammonia fuel and air supplied to the feeding ignition combustion device (120) includes: The airflow temperature and flow rate inside the connecting pipe (130) are obtained and recorded as exhaust heat flux; Determine whether the exhaust heat flux is less than the preset target heat flux. When the exhaust heat flux is less than the preset target heat flux, control the increase of the supply of ammonia fuel and air to the feed ignition combustion device (120).

10. The exhaust gas coupling heating control method for an ammonia engine according to claim 9, characterized in that: The method of controlling the heat flux in the heating pipe (230) based on the flow rate of ammonia fuel and air supplied to the feeding ignition combustion device (120) further includes: When the exhaust heat flux is not less than the preset target heat flux, the supply of ammonia fuel and air to the feed ignition combustion device (120) is reduced.

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