Ammonia decomposition system and ammonia engine exhaust coupling heat supply control method

Abstract

The invention relates to the technical field of ammonia decomposition, and discloses an ammonia decomposition system and an ammonia engine exhaust coupling heat supply control method.The ammonia decomposition system comprises a heat supply module, a heat exchange module, a heat exchange module and a heat exchange module, the heat supply module comprises a first shell and a feeding ignition combustion device, a connecting pipe is arranged on one side of the first shell, and a combustion chamber is arranged in the first shell; the feeding ignition combustion device is connected to the outer side, corresponding to the combustion chamber, of the first shell. 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 portion of the exhaust cavity into an air inlet cavity, and an air inlet is formed in the position, corresponding to the air inlet cavity, of the second shell; according to the ammonia decomposition device, exhaust gas of the ammonia engine can be used for providing high-grade heat energy for ammonia decomposition, the overall heat exchange efficiency is high, and the working stability is high.

Description

Technical Field

[0001] The present invention relates to the technical field of ammonia decomposition, and particularly relates to an ammonia decomposition system and a control method for coupling heat supply with the exhaust gas of an ammonia engine. Background Art

[0002] When an ammonia engine operates, in the engine cylinder, since ammonia itself, which is the main fuel, is not easily ignited and has a slow laminar burning speed, a part of hydrogen needs to be introduced into the cylinder to jet-ignite the ammonia fuel. And on-vehicle ammonia fuel itself is a high-content carrier of hydrogen, which is suitable for manufacturing hydrogen through on-vehicle online ammonia cracking.

[0003] Currently, most of the ammonia decomposition technologies use electric heating. However, on the vehicle platform of an ammonia engine, a large amount of electric energy cannot be provided for a long time, so the electric heating method cannot be directly adopted. In some ammonia decomposition technologies, the heat energy contained in the exhaust gas of the ammonia engine is utilized. However, the exhaust gas flow rate and temperature of the ammonia engine under different working conditions change significantly, resulting in a large temperature fluctuation of the final exhaust gas, making it difficult to directly supply heat for ammonia decomposition. Therefore, there is an urgent need for a system that can use the exhaust gas of an ammonia engine to provide stable heat supply for ammonia decomposition. Summary of the Invention

[0004] The purpose of the present invention is to provide an ammonia decomposition system and a control method for coupling heat supply with the exhaust gas of an ammonia engine, so as 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 of the present invention to solve its technical problems is:

[0006] An ammonia decomposition system includes: a heat supply module, including a first housing and a feeding and ignition combustion device. A connecting pipe is arranged on one side of the first housing, a combustion chamber is arranged inside the first housing, the feeding and ignition combustion device is connected to the outside of the first housing corresponding to the combustion chamber, and the feeding and ignition combustion device can burn inside the combustion chamber; an ammonia decomposition module, including a second housing and a decomposition pipe. A first partition and a second partition are arranged inside the second housing. The first partition divides the second housing into a heat exchange chamber and an exhaust chamber in the horizontal direction. The second partition divides the upper part of the exhaust chamber into an intake chamber. An intake port is arranged at the position of the second housing corresponding to the intake chamber, an air outlet is arranged at the position of the second housing corresponding to the exhaust chamber, a heat supply pipe and a first exhaust pipe are arranged at the position of the second housing corresponding to the heat exchange chamber. The heat supply pipe is connected to the first housing, and the combustion chamber can exhaust gas to the heat supply pipe. One end of the decomposition pipe is connected to one side of the first partition close to the heat exchange chamber, the other end of the decomposition pipe bends through the first partition and is connected to one side of the second partition close to the exhaust chamber, and both ends of the decomposition pipe are communicated with the intake chamber and the exhaust chamber respectively.

[0007] The technical solution has at least the following beneficial effects: The connecting pipe is used to access the ammonia engine of the peripheral device, and the air inlet on the second housing and the feeding and ignition combustion device are connected to the ammonia fuel input source of the peripheral device. During operation, the gas generated by the ammonia engine during the working or exhaust stroke is discharged into the first housing through the connecting pipe. The feeding and ignition combustion device burns in the combustion chamber, making the combustion chamber have a relatively high temperature. At this time, the exhaust gas of the ammonia engine entering the first housing exchanges heat with the combustion chamber, improving the exhaust heat flux of the ammonia engine and cooling and protecting the combustion chamber, which is beneficial to the long-term stable operation of the combustion chamber. The heated exhaust gas of the ammonia engine 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 a high-temperature mixed gas, providing high-grade heat energy to the heat exchange chamber. The ammonia gas flowing into the intake cavity from the air inlet flows into the decomposition pipe, first passes through the exhaust cavity along the decomposition pipe, and then enters the heat exchange cavity to be heated and raised in temperature. A catalyst can be installed in the part of the decomposition pipe located in the heat exchange cavity. When the ammonia gas passes through the catalyst, it contacts and reacts with the catalyst to generate a hydrogen-nitrogen mixed gas, which flows out of the decomposition pipe and enters the exhaust cavity. At this time, the temperature of the hydrogen-nitrogen mixed gas is relatively high, and part of the decomposition pipe is located in the exhaust cavity. The hydrogen-nitrogen mixed gas can preheat the ammonia gas just entering the decomposition pipe to ensure that the ammonia gas can be heated to the required temperature in the heat exchange cavity, improving the heat utilization rate. After the temperature of the hydrogen-nitrogen mixed gas itself decreases, it is discharged from the air outlet. 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.

[0008] As a further improvement of the above technical solution, the heat supply pipe and the first exhaust pipe are arranged on the side of the second housing away from the exhaust cavity. A baffle is arranged at the position between the heat supply pipe and the first exhaust pipe on the inner side of the second housing. The baffle extends towards the direction of the first partition. The decomposition pipe bends through the baffle and then bends through the first partition, and an air flow gap is formed between the baffle and the first partition. The baffle divides the interior of the second housing into a space for the gas to flow tortuously in the up and down direction. The high-temperature mixed gas entering the second housing from the heat supply pipe can directly heat and raise the temperature of the part of the decomposition pipe passing through the baffle upwards. In practical applications, the catalyst can be installed in this part of the decomposition pipe to ensure that the ammonia gas can reach a sufficient temperature during decomposition. The high-temperature mixed gas flows along the baffle to the first partition and enters the space below the baffle from the air flow gap downwards. At this time, the part of the decomposition pipe located between the first partition and the baffle can be heated, so as to heat and raise the temperature of the ammonia before contacting the catalyst, and finally be discharged from the first exhaust pipe. In this way, the heat exchange efficiency between 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 spoiler plates are arranged at intervals along the direction close to the first partition on the top side of the baffle. When the high-temperature mixed gas flows along the baffle, it will be blocked by the plurality of spoiler plates. The blocking of the high-temperature mixed gas by the spoiler plates can cause the high-temperature mixed gas to generate a backflow, delay the heat exchange time of the high-temperature mixed gas in the heat exchange chamber, and strengthen the heating of the decomposition tube.

[0010] As a further improvement of the above technical solution, the first housing 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 housing from the connecting pipe enters the heating pipe and serves as a heat exchange medium for providing heat for ammonia decomposition, while part of the ammonia engine exhaust gas is discharged from the second exhaust pipe. During use, the flow control valve can be used to control the amount of ammonia engine exhaust gas discharged from the second exhaust pipe, so as to adjust the temperature and flow rate of the high-temperature mixed gas in the heating 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 gas flow end of the second exhaust pipe relative to the flow control valve. The first exhaust pipe and the second exhaust pipe are connected, and the exhaust gases of the first exhaust pipe and the second exhaust pipe can be uniformly connected to the same downstream gas treatment module, improving the convenience of overall installation and use.

[0012] As a further improvement of the above technical solution, a plurality of baffle plates are arranged in the exhaust chamber, and the upper and lower adjacent baffle plates are staggered in the up and down direction. The hydrogen-nitrogen mixed gas discharged from the decomposition tube into the exhaust chamber can preheat and raise the temperature of the ammonia gas just entering the decomposition tube, and the plurality of baffle plates staggered up and down can form a space in the exhaust chamber for guiding the gas to flow in a serpentine shape. In this way, the flow stroke and heat exchange time of the hydrogen-nitrogen mixed gas in the exhaust chamber can be extended, and the preheating effect on the ammonia gas in the decomposition tube can be improved.

[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 housing. The upper and lower ends of the combustion chamber respectively extend to the inner top side and the inner bottom side of the first housing. A gas guide pipe is arranged at the position on the top side of the first housing opposite to the combustion chamber, and the gas guide pipe is connected to the heating pipe. When the feed ignition combustion device burns in the combustion chamber, its heat is dissipated to the heat exchange gap between the combustion chamber and the first housing. At this time, the ammonia engine exhaust gas entering the first housing from the connecting pipe can flow around the combustion chamber, which can not only extend the flow stroke of the ammonia engine exhaust gas and improve the heat exchange effect with the combustion chamber, but also better cool and protect the combustion chamber. The exhaust gas after combustion in the combustion chamber enters the heating pipe through the gas guide pipe and is mixed with the ammonia engine exhaust gas directly entering the heating pipe from the first housing.

[0014] An ammonia engine exhaust coupling heat supply control method, which applies the above ammonia decomposition system, includes:

[0015] Connect the exhaust port of the ammonia engine to the connecting pipe and exhaust gas into the connecting pipe;

[0016] Supply ammonia fuel and air to the feeding ignition combustion device;

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

[0018] The technical solution has at least the following beneficial effects: When using the exhaust gas of the ammonia engine to heat the ammonia decomposition, the exhaust heat flux and flow rate of the ammonia engine are different under different working conditions such as cold start, low working condition idling, high speed and large load. At this time, the heat flux in the heat supply pipe can be adjusted by controlling the flow rates of the ammonia fuel and air supplied to the feeding ignition combustion device, so as to stably supply heat to the ammonia decomposition module.

[0019] As a further improvement of the above technical solution, the control of the heat flux in the heat supply pipe according to the flow rates of the ammonia fuel and air supplied to the feeding ignition combustion device includes:

[0020] Obtain the air flow temperature and flow rate in the connecting pipe, denoted as the exhaust heat flux;

[0021] Judge whether the exhaust heat flux is less than a preset target heat flux. When the exhaust heat flux is less than the preset target heat flux, control to increase the ammonia fuel and air supplied to the feeding ignition combustion device.

[0022] As a further improvement of the above technical solution, the control of the heat flux in the heat supply pipe according to the flow rates of the ammonia fuel and air supplied to the feeding ignition combustion device further includes:

[0023] When the exhaust heat flux is not less than the preset target heat flux, control to reduce the ammonia fuel and air supplied to the feeding ignition combustion device. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly describe the drawings required for the description of the embodiments. Obviously, the described drawings are only a part of the embodiments of the present invention, rather than all the embodiments. Those skilled in the art can also obtain other design solutions and drawings based on these drawings without creative efforts.

[0025] Figure 1 It is a three-dimensional view of the ammonia decomposition system of the present invention.

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

[0027] Figure 3 is Figure 2 a partial enlarged schematic diagram of part A of

[0028] In the attached drawings: 110 - the first housing, 120 - the feeding and ignition combustion device, 130 - the connecting pipe, 140 - the combustion chamber, 150 - the heat exchange gap, 160 - the air guide pipe, 210 - the second housing, 211 - the first partition board, 212 - the second partition board, 213 - the heat exchange chamber, 214 - the exhaust chamber, 215 - the intake chamber, 216 - the intake port, 217 - the outlet port, 220 - the decomposition pipe, 230 - the heating pipe, 240 - the first exhaust pipe, 250 - the baffle plate, 251 - the spoiler, 260 - the second exhaust pipe, 261 - the flow control valve, 270 - the baffle, 310 - the ammonia fuel delivery pipe, 320 - the air delivery pipe, 330 - the high-energy ignition electrode, 340 - the air distribution plate, 350 - the ammonia fuel nozzle, 360 - the air wind disk. Specific embodiments

[0029] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the attached drawings, in which the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the attached drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0030] In the description of the present invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the attached drawings, and are 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, and therefore should not be construed as a limitation to the present invention.

[0031] In the description of the present invention, the meaning of several is one or more, the meaning of multiple is more than two, understand greater than, less than, exceeding, etc. as not including the present number, and understand above, below, within, etc. as including the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0032] 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 meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0033] Refer to Figure 1 WithFigure 2 , an ammonia decomposition system, comprising a heat supply module and an ammonia decomposition module. Among them, the heat supply module includes a first housing 110 and a feeding and ignition combustion device 120. A connecting pipe 130 is arranged on one side of the first housing 110. A combustion chamber 140 is arranged inside the first housing 110. The feeding and ignition combustion device 120 is connected to the outside of the first housing 110 corresponding to the combustion chamber 140, and the feeding and ignition combustion device 120 can burn inside the combustion chamber 140; the ammonia decomposition module includes a second housing 210 and a decomposition pipe 220. A first partition 211 and a second partition 212 are arranged inside the second housing 210. The first partition 211 divides the second housing 210 in the horizontal direction to form a heat exchange chamber 213 and an exhaust chamber 214. The second partition 212 divides the upper part of the exhaust chamber 214 to form an air inlet chamber 215. An air inlet 216 is arranged at the position of the second housing 210 corresponding to the air inlet chamber 215. An air outlet 217 is arranged at the position of the second housing 210 corresponding to the exhaust chamber 214. A heat supply pipe 230 and a first exhaust pipe 240 are arranged at the position of the second housing 210 corresponding to the heat exchange chamber 213. The heat supply pipe 230 is connected to the first housing 110, and the combustion chamber 140 can exhaust gas to the heat supply pipe 230. One end of the decomposition pipe 220 is connected to the side of the first partition 211 close to the heat exchange chamber 213, and the other end of the decomposition pipe 220 bends through the first partition 211 and is connected to the side of the second partition 212 close to the exhaust chamber 214. Both ends of the decomposition pipe 220 are communicated with the air inlet chamber 215 and the exhaust chamber 214 respectively. In practical applications, the number of decomposition pipes 220 is multiple, so as to improve the efficiency of ammonia decomposition.

[0034] As described above, the connecting pipe 130 is used to connect to an ammonia engine of a peripheral device, and the air inlet 216 on the second housing 210 and the feeding ignition combustion device 120 are connected to an ammonia fuel input source of the peripheral device. During operation, the gas generated by the ammonia engine during the working or exhaust stroke is discharged into the first housing 110 through the connecting pipe 130. The feeding ignition combustion device 120 burns in the combustion chamber 140, making the combustion chamber 140 have a relatively high temperature. At this time, the exhaust gas of the ammonia engine entering the first housing 110 exchanges heat with the combustion chamber 140, improving the exhaust heat flux of the ammonia engine and cooling and protecting the combustion chamber 140, which is beneficial to the long-term stable operation of the combustion chamber 140. The heated exhaust gas of the ammonia engine 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 to form a high-temperature mixed gas, providing high-grade heat energy to the heat exchange chamber 213. The ammonia gas entering the intake chamber 215 from the air inlet 216 flows into the decomposition pipe 220, first passes through the exhaust chamber 214 along the decomposition pipe 220, and then enters the heat exchange chamber 213 to be heated and raised in temperature. A catalyst can be installed in the part of the decomposition pipe 220 located in the heat exchange chamber 213. When the ammonia gas passes through the catalyst, it contacts with the catalyst to generate a hydrogen-nitrogen mixed gas, which flows out of the decomposition pipe 220 and enters the exhaust chamber 214. At this time, the temperature of the hydrogen-nitrogen mixed gas is relatively high, and a part of the decomposition pipe 220 is located in the exhaust chamber 214. The hydrogen-nitrogen mixed gas can preheat the ammonia gas just entering the decomposition pipe 220 to ensure that the ammonia gas can be heated to the required temperature in the heat exchange chamber 213, improving the heat utilization rate. After the temperature of the hydrogen-nitrogen mixed gas itself decreases, it 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 Figure 3 shown, the feeding ignition combustion device 120 includes an ammonia fuel delivery pipe 310, an air delivery pipe 320, a high-energy ignition electrode 330, an air distribution plate 340, an ammonia fuel nozzle 350, and an air disk 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 disk 360 is connected to the top of the air delivery pipe 320. The ammonia combustion nozzle passes through the air disk 360 and extends into the combustion chamber 140. An air distribution plate 340 is installed in the middle of the air delivery pipe 320. In the feeding ignition combustion device 120, after the ammonia fuel is regulated in flow rate, it is sprayed into the combustion chamber 140 through the ammonia fuel delivery pipe 310 to the ammonia fuel nozzle 350. At the same time, the air is delivered by the air delivery pipe 320 after being regulated in flow rate, passes through the air distribution plate 340, and is sprayed into the combustion chamber 140 by the air disk 360. The ammonia fuel and the air are highly mixed in the combustion chamber 140 and are ignited by the ignition electrode to generate an ammonia combustion flame. While heating the combustion chamber 140, the ammonia combustion exhaust gas is discharged into the heat supply pipe 230.

[0036] In order to improve the heat exchange effect between the high-temperature mixed gas and the decomposition tube 220, in this embodiment, the heating tube 230 and the first exhaust pipe 240 are arranged on the side of the second housing 210 away from the exhaust cavity 214. A baffle 250 is arranged at a position between the heating tube 230 and the first exhaust pipe 240 on the inner side of the second housing 210. The baffle 250 extends towards the first partition 211. The decomposition tube 220 bends through the baffle 250 and then bends through the first partition 211. An air flow gap is formed between the baffle 250 and the first partition 211. The baffle 250 divides the interior of the second housing 210 into a space for the gas to flow tortuously in the vertical direction. The high-temperature mixed gas entering the second housing 210 from the heating tube 230 can directly heat and raise the temperature of the part of the decomposition tube 220 passing through the baffle 250 upwards. In practical applications, the catalyst can be loaded into the decomposition tube 220 of this part to ensure that the ammonia can reach a sufficient temperature during decomposition. The high-temperature mixed gas flows along the baffle 250 to the first partition 211 and enters the space below the baffle 250 from the air flow gap downwards. At this time, the part of the decomposition tube 220 between the first partition 211 and the baffle 250 can be heated, so as to heat and raise the temperature of the ammonia before contacting the catalyst, and finally be discharged from the first exhaust pipe 240. In this way, the heat exchange efficiency between the high-temperature mixed gas and the decomposition tube 220 can be improved.

[0037] Further, a plurality of spoiler plates 251 are arranged at intervals along the direction close to the first partition 211 on the top side of the baffle 250. In practical applications, the spoiler plates 251 on the top side of the baffle 250 extend upwards, and two spoiler plates 251 can also be connected to the side of the baffle 250 close to the first partition 211. The two spoiler plates 251 extend obliquely in opposite directions. When the high-temperature mixed gas flows along the baffle 250, it will be blocked by the plurality of spoiler plates 251. The blocking of the high-temperature mixed gas by the spoiler plates 251 can cause the high-temperature mixed gas to generate a backflow, 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 housing 210. Starting from the connection of the decomposition tube 220 to the first partition 211, the part of the decomposition tube 220 extending horizontally above the baffle 250 is the decomposition section, the part bending downwards and passing through the baffle 250 is the temperature-raising section, the part extending horizontally below the baffle 250 is the heating section, and the part bending upwards and connecting to the second partition 212 after passing through the first partition 211 is the preheating section. The preheating section is preheated by the hydrogen-nitrogen mixed gas decomposed. The heating section, the temperature-raising section and the decomposition section are mainly heated by the high-temperature mixed gas. Catalysts such as ruthenium-based or cobalt-molybdenum-based catalysts are placed in the decomposition section. In order to position the catalyst, supports or plugs can be placed on both sides of the catalyst in the decomposition section to maintain the stability of the catalyst loading.

[0039] In order to better regulate the heat flux in the heat supply pipe 230, the utilization amount of the ammonia engine exhaust can be controlled. Therefore, a structure for directly controlling the ammonia engine exhaust can be provided on the first housing 110. Specifically, 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. Part of the ammonia engine exhaust entering the first housing 110 from the connecting pipe 130 enters the heat supply pipe 230 and serves as a heat exchange working medium for providing heat for ammonia decomposition, while part of the ammonia engine exhaust is discharged from the second exhaust pipe 260. During use, the flow control valve 261 can be used to control the amount of ammonia engine exhaust discharged from the second exhaust pipe 260, thereby adjusting the temperature and flow rate of the high-temperature mixed gas in the heat supply pipe 230.

[0040] Furthermore, the first exhaust pipe 240 is connected to the second exhaust pipe 260, and the position where the first exhaust pipe 240 is connected to the second exhaust pipe 260 is closer to the gas flow end of the second exhaust pipe 260 relative to the flow control valve 261. The connection between the first exhaust pipe 240 and the second exhaust pipe 260 can connect the exhausts of the first exhaust pipe 240 and the second exhaust pipe 260 to the same downstream gas treatment module in a unified manner, improving the convenience of overall installation and use.

[0041] In order to improve the heat exchange efficiency of the generated hydrogen-nitrogen mixed gas for preheating in the exhaust chamber 214, in this embodiment, a plurality of baffle plates 270 are provided in the exhaust chamber 214, and the upper and lower adjacent baffle plates 270 are staggered in the up-down direction. For example, there are two baffle plates 270, and the two baffle plates 270 are respectively connected to both sides of the exhaust chamber 214. The hydrogen-nitrogen mixed gas discharged from the decomposition pipe 220 into the exhaust chamber 214 can preheat and raise the temperature of the ammonia gas just entering the decomposition pipe 220, and the plurality of baffle plates 270 staggered up and down can form a space in the exhaust chamber 214 for guiding the gas to flow in a serpentine shape. In this way, the flow travel and heat exchange time of the hydrogen-nitrogen mixed gas in the exhaust chamber 214 can be extended, improving the preheating effect on the ammonia gas in the decomposition pipe 220.

[0042] After the ammonia engine exhaust enters the first housing 110, it can only exchange heat with one side of the combustion chamber 140. To improve the heat exchange efficiency with the combustion chamber 140, the ammonia engine exhaust can flow around the entire outer side of the combustion chamber 140 to achieve heat exchange. Specifically, a heat exchange gap 150 is provided between the outer side of the combustion chamber 140 and the inner side of the first housing 110. The upper and lower ends of the combustion chamber 140 respectively extend to the inner top side and the inner bottom side of the first housing 110. A gas guide pipe 160 is provided at the position on the top side of the first housing 110 facing the combustion chamber 140, and the gas guide pipe 160 is connected to the heat supply pipe 230. When the feeding ignition combustion device 120 burns in the combustion chamber 140, its heat dissipates to the heat exchange gap 150 located between the combustion chamber 140 and the first housing 110. At this time, the ammonia engine exhaust entering the first housing 110 from the connecting pipe 130 can flow around the combustion chamber 140, which can not only extend the flow stroke of the ammonia engine exhaust, improve the heat exchange effect with the combustion chamber 140, but also better cool and protect the combustion chamber 140. And the exhaust gas after combustion in the combustion chamber 140 enters the heat supply pipe 230 from the gas guide pipe 160 and is mixed with the ammonia engine exhaust directly entering the heat supply pipe 230 from the first housing 110.

[0043] An ammonia engine exhaust coupling heat supply control method, which applies the above ammonia decomposition system, includes but is not limited to the following steps:

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

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

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

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

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

[0049] Step S310, obtain the air flow temperature and flow rate in the connecting pipe 130, and record it as the exhaust heat flux;

[0050] Step S320, determine whether the exhaust heat flux is less than a preset target heat flux;

[0051] When the exhaust heat flux is less than the preset target heat flux, go to step S321 to control an increase in 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, go to step S322 to control a decrease in 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 thermal energy provided by the ammonia engine exhaust is relatively low at this time, and combustion is required 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 mix-heat the ammonia engine exhaust to reach the required ammonia decomposition heating temperature; when the exhaust heat flux is not less than the preset target heat flux, the thermal energy provided by the ammonia engine exhaust is relatively high at this time, and the feed ignition combustion device 120 does not need to provide too much heat. At this time, controlling a decrease in the amount of ammonia fuel supplied to the feed ignition combustion device 120 can make the heat flux in the heat supply pipe 230 reach the ammonia decomposition heating temperature.

[0054] Further, an example is given to illustrate the above ammonia engine exhaust coupled heating control method:

[0055] When the ammonia engine is cold-started and idling under low load conditions, the hydrogen required for jet ignition of the ammonia engine is temporarily provided by an external hydrogen storage tank. At this time, it is detected that the exhaust gas flow rate and temperature of the ammonia engine are relatively low, about 100 kg / h and 100 °C respectively. At this time, more ammonia fuel and air are introduced into the feed ignition combustion device 120, so that the feed ignition combustion device 120 generates more high-temperature ammonia combustion gas (flow rate 42 kg / h, temperature 1300 °C) in the combustion chamber 140. The ammonia engine exhaust flows through the outer wall of the combustion chamber 140 in the first housing 110 and cools and protects it, so that the wall surface is always lower than 800 °C, and at the same time it is heated to 300 °C itself. Then, control a part of the ammonia engine exhaust (42 kg / h) to enter the external tail gas after-treatment module via the second exhaust pipe 260, and another part of the ammonia engine exhaust (58 kg / h) is mixed with the exhaust gas of the combustion chamber 140 in the heat supply pipe 230, so that the total exhaust gas flow rate flowing to the ammonia decomposition module reaches 100 kg / h, and the temperature is 800 °C. The decomposition pipe 220 undergoes heat exchange in the second housing 210, and starts to decompose ammonia to generate hydrogen, which is supplied to the ammonia engine and replenishes the external hydrogen storage tank. The temperature of the ammonia engine exhaust decreases to 400 °C after heat exchange, enters the second exhaust pipe 260 from the first exhaust pipe 240 for exhaust gas mixing, and the temperature remains at 300 °C after mixing, and then enters the external tail gas after-treatment module for efficient after-treatment.

[0056] When the ammonia engine is operating at high speed and under heavy load, it is detected that the exhaust gas flow rate and temperature of the ammonia engine are relatively high, approximately 1200 kg / h and 520 °C respectively. At this time, a small amount of ammonia fuel and air are introduced, so that the feed ignition combustion device 120 generates less high-temperature ammonia combustion gas (flow rate 33 kg / h, temperature 1300 °C) when working in the combustion chamber 140. The exhaust gas of the ammonia engine flows through the wall of the combustion chamber 140 in the first housing 110 and cools and protects it, so that the wall surface remains below 800 °C, and at the same time, the exhaust gas itself is heated to 530 °C. Then, part of the exhaust gas of the ammonia engine (1150 kg / h) is discharged and enters the tail gas after-treatment module connecting pipe 130 via the second exhaust pipe 260, and another part of the exhaust gas of the ammonia engine (50 kg / h) is mixed with the exhaust gas of the combustion chamber 140 in the heat supply pipe 230, so that the total exhaust gas flow rate flowing to the ammonia decomposition module reaches 83 kg / h, and the temperature is 900 °C. The decomposition pipe 220 exchanges heat in the second housing 210, and starts to decompose ammonia to generate hydrogen, which is supplied to the ammonia engine and supplemented with an external hydrogen storage tank. After the exhaust gas exchanges heat, the temperature is reduced to 440 °C, and it enters the second exhaust pipe 260 from the first exhaust pipe 240 for exhaust gas mixing. After mixing, the temperature is maintained at 500 °C, and it enters the tail gas after-treatment module for efficient after-treatment.

[0057] Under the condition between low-idle condition and high-speed heavy load, the ammonia feed ignition combustion device 120 module is controlled to be coupled with different ammonia engine exhaust gas flow rates and temperatures, so as to provide high-temperature exhaust gas with a flow rate between 83 - 100 kg / h and a temperature between 800 - 900 °C for the ammonia decomposition module, and at the same time, the exhaust gas heat flux entering the tail gas after-treatment module is between 300 - 500 °C for efficient after-treatment.

[0058] The above has specifically described the preferred embodiments of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art can also make various equivalent variations or substitutions without departing from the spirit of the present invention, and these equivalent variations 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: A heating module comprises a first shell (110) and a feed ignition combustion device (120); a connecting pipe (130) is provided on one side of the first shell (110); a combustion chamber (140) is provided inside the first shell (110); the feed ignition combustion device (120) is connected to the outer side of the first shell (110) corresponding to the combustion chamber (140); and the feed ignition combustion device (120) can burn in the combustion chamber (140); An ammonia decomposition module comprises a second shell (210) and a decomposition tube (220); a first partition (211) and a second partition (212) are arranged in the second shell (210); the first partition (211) divides the second shell (210) in a horizontal direction to form a heat exchange chamber (213) and an exhaust chamber (214); the second partition (212) divides the upper portion of the exhaust chamber (214) to form an air intake chamber (215); an air inlet (216) is arranged at a position of the second shell (210) corresponding to the air intake chamber (215); an air outlet (217) is arranged at a position of the second shell (210) corresponding to the exhaust chamber (214); and the second shell A heat supply pipe (230) and a first exhaust pipe (240) are provided at a position corresponding to the heat exchange chamber (213) (210); the heat supply pipe (230) is connected to the first shell (110); the combustion chamber (140) can exhaust gas to the heat supply pipe (230); one end of the decomposition pipe (220) is connected to a side of the first partition plate (211) close to the heat exchange chamber (213); the other end of the decomposition pipe (220) is bent and passes through the first partition plate (211) and is connected to a side of the second partition plate (212) close to the exhaust chamber (214); the two ends of the decomposition pipe (220) are respectively connected to the air inlet chamber (215) and the exhaust chamber (214).

2. An ammonia decomposition system according to claim 1, characterized in that: The heating pipe (230) and the first exhaust pipe (240) are arranged on a side of the second shell (210) away from the exhaust chamber (214); a baffle (250) is arranged on the inner side of the second shell (210) between the heating pipe (230) and the first exhaust pipe (240); the baffle (250) extends in the direction of the first partition (211); the decomposition tube (220) is bent and passes through the baffle (250) and then bent and passes through the first partition (211); an airflow gap is formed between the baffle (250) and the first partition (211).

3. An ammonia decomposition system according to claim 2, characterized in that: A plurality of spoilers (251) are arranged at intervals on the top side of the baffle (250) in a direction close to the first partition plate (211).

4. An ammonia decomposition system according to claim 2, characterized in that: 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).

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 where 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).

6. An ammonia decomposition system according to claim 1, characterized in that: A plurality of baffles (270) are arranged in the exhaust cavity (214), and two upper and lower adjacent baffles (270) are staggered with each other in the up-down 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) respectively extend to the inner top side and the inner bottom side of the first shell (110); an air guide pipe (160) is provided at a position of the top side of the first shell (110) facing the combustion chamber (140); and the air guide pipe (160) is connected to the heat supply pipe (230).

8. An exhaust-coupled heating control method for an ammonia engine, characterized in that: The ammonia decomposition system according to any one of claims 1 to 7 comprises: Connecting the exhaust port of the ammonia engine to the connecting pipe (130), and exhausting the air into the connecting pipe (130); Supplying ammonia fuel and air to the feed ignition combustion device (120); The heat flux in the heat supply 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-coupled heating control method for an ammonia engine according to claim 8, characterized in that: The method of controlling the heat flux in the heat supply pipe (230) according to the flow rate of the ammonia fuel and the air supplied to the feed ignition combustion device (120) comprises: Obtaining the air flow temperature and flow rate in the connecting pipe (130), which are recorded as exhaust heat flux; It is determined whether the exhaust heat flux is less than a preset target heat flux, and when the exhaust heat flux is less than the preset target heat flux, the supply of ammonia fuel and air to the feed ignition combustion device (120) is controlled to increase.

10. The exhaust-coupled heating control method for an ammonia engine according to claim 9, characterized in that: The method of controlling the heat flux in the heat supply pipe (230) according to the flow rate of the ammonia fuel and the air supplied to the feed 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 controlled to be reduced.

Images