Catalytic combustion assisted preheating ammonia hydrogen engine system and operating method

Abstract

The application discloses a catalytic combustion assisted preheating ammonia hydrogen engine system and an operation method thereof. The system comprises an ammonia decomposition system, an NOx decomposition system, an ammonia hydrogen engine, a flameless combustion system, an air source and an ammonia source. A preheating cooling cavity rapidly heats the inner wall surface of a combustion cavity and reaches the required temperature of flameless combustion. The tail gas generated by combustion further preheats each component of the ammonia decomposition system and the NOx decomposition system, thereby improving the response speed in the starting stage. In the normal operation stage, the high-temperature combustion tail gas generated by flameless combustion is sequentially introduced into a heating cavity and a combustion tail gas heat supply cavity, the ammonia decomposition cavity is heated to decompose the ammonia gas in the ammonia decomposition cavity into hydrogen gas, and the NOx decomposition cavity is heated to decompose the NOx in the engine tail gas into NO. The combustion-supporting mixed gas is preheated by the preheating cooling cavity, sprayed into the combustion cavity, mixed with the ammonia gas and subjected to flameless combustion, thereby further assisting the flameless combustion.

Description

Technical Field

[0001] This invention relates to the field of energy-saving and new energy vehicles, and in particular to an ammonia-hydrogen engine system and its operation method with catalytic combustion-assisted preheating. Background Technology

[0002] Ammonia, as a clean fuel, is considered key to the future energy transition because it does not produce carbon dioxide during combustion and has high energy density and good storage and transportation characteristics. To reduce the environmental impact of engines, ammonia-hydrogen engines have been developed by utilizing the combustion characteristics of ammonia and hydrogen, truly achieving efficient and clean zero-carbon combustion engines. However, the direct combustion of ammonia produces large amounts of nitrogen oxides (NOx).

[0003] Existing exhaust gas treatment devices require additional heat and ammonia to operate, wasting energy in the engine system and reducing overall system energy efficiency. Although existing methods for recovering heat from engine exhaust gas are provided, they do not consider that NO can aid ammonia combustion, thus wasting engine exhaust gas. Furthermore, due to the low temperature of engine exhaust gas, the heat recovery efficiency is too low. Moreover, existing exhaust gas treatment devices cannot cope with the variable operating conditions of on-board internal combustion engine systems and cannot meet the rapid response requirements of on-board internal combustion engine systems. Summary of the Invention

[0004] The purpose of this invention is to provide an ammonia-hydrogen engine system and operating method with catalytic combustion-assisted preheating, in order to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0005] The technical solution adopted to solve the above-mentioned technical problems is as follows:

[0006] This invention provides an ammonia-hydrogen engine system with catalytic combustion-assisted preheating, comprising:

[0007] An ammonia decomposition system includes an ammonia decomposer, wherein the ammonia decomposer is provided with a heating chamber and an ammonia decomposition chamber having a heat exchange relationship between the walls, and the ammonia decomposition chamber is provided with an ammonia decomposition catalyst;

[0008] The NOx decomposition system includes a NOx decomposer and an ammonia-hydrogen engine. The NOx decomposer is provided with a NOx decomposition chamber and a combustion exhaust gas heating chamber with a heat exchange relationship between the two walls. The heating chamber is connected to the combustion exhaust gas heating chamber. The combustion exhaust gas heating chamber is provided with a second combustion exhaust gas outlet connected to the outside. The NOx decomposition chamber is provided with a NOx decomposition catalyst.

[0009] An ammonia-hydrogen engine is provided with an engine fuel input end and an engine exhaust gas output end. The engine exhaust gas output end is connected to the NOx decomposition chamber, and the engine fuel input end is connected to the ammonia decomposition chamber.

[0010] A flameless combustion system includes a furnace body and an ignition device. The furnace body has a combustion chamber and a preheating and cooling chamber with a heat exchange relationship between the walls. The preheating and cooling chamber contains an ammonia combustion catalyst. The combustion chamber has an ammonia combustion nozzle, an air jet port, and a tail gas exhaust port. The air jet port and the ammonia combustion nozzle are respectively located on two opposite inner sides of the combustion chamber. The tail gas exhaust port and the air jet port are located on the same side of the combustion chamber. The air jet port is connected to the preheating and cooling chamber. The tail gas exhaust port is connected to the heating chamber. The preheating and cooling chamber has a combustion-supporting gas port. The ignition device is located in the preheating and cooling chamber. The combustion-supporting gas port is connected to the NOx decomposition chamber.

[0011] An air source is connected to the combustion-supporting gas mixing port;

[0012] The ammonia gas source is connected to the ammonia decomposition chamber, the ammonia combustion nozzle, the combustion-supporting mixture port, and the engine fuel input terminal, respectively.

[0013] The beneficial effects of the ammonia-hydrogen engine system of the present invention are:

[0014] During the start-up phase, the ammonia-hydrogen internal combustion engine and the preheating and cooling chamber of the flameless combustion system are simultaneously ignited. The preheating and cooling chamber rapidly heats the inner wall of the combustion chamber to the temperature required for flameless combustion. The exhaust gas produced by combustion further preheats the various components of the ammonia decomposition system and the NOx decomposition system, improving the response speed during the start-up phase. During normal operation, the temperature of the inner wall of the combustion chamber reaches the temperature required for flameless combustion. By changing the flow path of ammonia, ammonia is introduced into the combustion chamber to initiate flameless combustion. The high-temperature combustion exhaust gas produced by flameless combustion is sequentially introduced into the heating chamber and the combustion exhaust gas heating chamber to heat the ammonia decomposition chamber. Under the action of the ammonia decomposition catalyst, the ammonia in the ammonia decomposition chamber is decomposed into hydrogen. The NOx decomposition chamber is also heated, and under the action of the NOx decomposition catalyst, the NOx in the engine exhaust gas is decomposed into NO to form combustion-supporting exhaust gas. The gas is mixed with a set amount of air to form a combustion-supporting mixture with a set oxygen concentration. After being preheated in a preheating and cooling chamber, the combustion-supporting mixture is injected into the combustion chamber and mixed with ammonia for flameless combustion. This further assists in flameless combustion, suppresses NOx formation, and produces high-temperature combustion exhaust gas, as well as heat for heating the ammonia decomposition chamber and NOx decomposition chamber. This not only utilizes the nitrogen oxides produced by the ammonia-hydrogen engine but also produces almost no additional nitrogen oxide emissions through optimized combustion technology. At the same time, the combustion-supporting mixture in the preheating and cooling chamber returns the absorbed heat to the combustion chamber, improving heat utilization and maintaining a high-temperature environment in the combustion chamber to ensure continuous flameless combustion. No additional preheating equipment or energy input is required, simplifying the system structure, improving preheating efficiency, and shortening preheating time, providing rapid and effective preparation conditions for stable flameless combustion.

[0015] As a further improvement to the above technical solution, an ammonia decomposition gas compressor and a high-pressure hydrogen buffer tank are sequentially provided between the outlet of the ammonia decomposition chamber and the fuel input end of the engine.

[0016] As a further improvement to the above technical solution, a combustion gas flow detector is provided between the NOx decomposition chamber and the combustion gas mixing port.

[0017] As a further improvement to the above technical solution, an air compressor and an air flow controller are sequentially provided between the air source and the combustion-supporting gas mixing port.

[0018] As a further improvement to the above technical solution, the preheating and cooling chamber is wrapped around the outside of the combustion chamber.

[0019] As a further improvement to the above technical solution, the preheating and cooling chamber is provided with multiple heat-conducting fins extending along the airflow direction. The multiple heat-conducting fins are arranged in a ring with intervals. The heat-conducting fins are connected to the outer peripheral wall of the combustion chamber and the inner peripheral wall of the preheating and cooling chamber. The ammonia combustion catalyst is coated on the surface of the heat-conducting fins.

[0020] As a further improvement to the above technical solution, a first fuel control valve is provided between the ammonia source and the combustion-supporting gas mixing port;

[0021] A second fuel control valve is provided between the ammonia gas source and the ammonia combustion nozzle.

[0022] As a further improvement to the above technical solution, the ammonia decomposition chamber is arranged around the outer periphery of the heating chamber.

[0023] As a further improvement to the above technical solution, the ammonia decomposition chamber is provided with multiple decomposition guide vanes, which are arranged alternately and staggered along the airflow direction to form a serpentine decomposition baffle channel, and the ammonia decomposition catalyst is filled in the decomposition baffle channel.

[0024] Furthermore, the present invention also proposes an operating method applicable to the aforementioned ammonia-hydrogen engine system, the operating method comprising:

[0025] During the start-up phase of the ammonia-hydrogen engine, the ammonia-hydrogen engine is started, and the engine exhaust gas enters the preheating and cooling chamber. At the same time, ammonia and air are introduced into the preheating and cooling chamber according to the first preset ammonia supply and the first preset air supply. Ignition is performed by the ignition device, and a combustion reaction occurs in the preheating and cooling chamber under the action of the ammonia combustion catalyst. The preheating and cooling chamber heats the combustion chamber, and the exhaust gas generated by combustion preheats the ammonia decomposer and the NOx decomposer.

[0026] After the ammonia-hydrogen internal combustion engine has been running for a predetermined time, the temperature of the inner wall of the combustion chamber reaches the temperature required for flameless combustion. Ammonia is then introduced into the combustion chamber according to the second ammonia supply rate, and the supply of ammonia to the preheating and cooling chamber is stopped. Flameless combustion is then initiated. Ammonia is then introduced into the ammonia decomposition chamber according to the third ammonia supply rate. The high-temperature combustion exhaust gas generated by the combustion is introduced into the heating chamber to heat the ammonia decomposition chamber. Under the action of the ammonia decomposition catalyst, the ammonia in the ammonia decomposition chamber is decomposed into hydrogen, which is then supplied to the ammonia-hydrogen engine for combustion support. The engine exhaust gas generated by the ammonia-hydrogen engine is introduced into the NOx decomposition chamber. The high-temperature exhaust gas that has passed through the heating chamber is introduced into the combustion exhaust gas heating chamber to heat the NOx decomposition chamber. Under the action of the NOx decomposition catalyst, the NOx in the engine exhaust gas is decomposed into NO to form combustion support exhaust gas. The combustion support exhaust gas is then introduced into the preheating and cooling chamber to further assist flameless combustion.

[0027] When the ammonia-hydrogen internal combustion engine switches from a low operating condition to a high operating condition, the flow rate of the combustion-supporting exhaust gas is detected to control the amount of air entering the preheating and cooling chamber, thereby controlling the oxygen concentration in the preheating and cooling chamber to achieve stable flameless combustion.

[0028] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0030] Figure 1 This is a schematic diagram of an embodiment of the ammonia-hydrogen engine system provided by the present invention;

[0031] Figure 2 This is a schematic diagram of an embodiment of the ammonia decomposer provided by the present invention;

[0032] Figure 3 This is a schematic diagram of an embodiment of the NOx decomposer provided by the present invention;

[0033] Figure 4 This is a schematic diagram of an embodiment of the flameless combustion system provided by the present invention;

[0034] Figure 5 This is a control flowchart of an embodiment of the operating method provided by the present invention;

[0035] Icon labels:

[0036] Ammonia decomposition system 100; ammonia decomposer 110; heating chamber 111; ammonia decomposition chamber 112; ammonia decomposition catalyst 113; fuel exhaust gas nozzle 114; first fuel exhaust gas outlet 115; ammonia decomposition gas outlet 116; ammonia gas to be decomposed inlet 117.

[0037] NOx decomposition system 200; NOx decomposer 210; NOx decomposition chamber 211; combustion exhaust gas heating chamber 212; combustion exhaust gas inlet 213; second combustion exhaust gas outlet 214; engine exhaust gas inlet 215; combustion-supporting exhaust gas outlet 216; NOx decomposition catalyst 217; combustion-supporting exhaust gas valve 218.

[0038] Flameless combustion system 300; furnace body 310; combustion chamber 311; preheating and cooling chamber 312; ammonia combustion nozzle 313; air jet port 314; exhaust gas port 315; combustion-supporting mixture port 316; first control valve 317; second fuel control valve 318; ammonia combustion catalyst 319; ignition device 320;

[0039] Air source 400;

[0040] Ammonia source 500;

[0041] Ammonia-hydrogen engine 600; engine fuel input terminal 610; engine exhaust output terminal 620;

[0042] Ammonia decomposition gas compressor 700; High-pressure hydrogen buffer tank 710;

[0043] Air compressor 800; air flow controller 810;

[0044] 900 gas flow detector. Detailed Implementation

[0045] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0046] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0047] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0048] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0049] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0050] like Figures 1 to 4 As shown, an ammonia-hydrogen engine system with catalytic combustion-assisted preheating according to the present invention includes: an ammonia decomposition system 100, a NOx decomposition system 200, a flameless combustion system 300, an air source 400, an ammonia source 500, and an ammonia-hydrogen engine 600.

[0051] Ammonia source 500 is used to supply ammonia, while air source 400 is used to supply air.

[0052] The ammonia decomposition system 100 includes an ammonia decomposer 110, such as Figure 2As shown, the ammonia decomposer 110 is provided with a heating chamber 111 and an ammonia decomposition chamber 112. The heating chamber 111 and the ammonia decomposition chamber 112 have a heat exchange relationship between the walls. In order to improve the heat exchange efficiency between the heating chamber 111 and the ammonia decomposition chamber 112, the ammonia decomposition chamber 112 in this embodiment is arranged around the outer periphery of the heating chamber 111.

[0053] In this embodiment, the ammonia decomposition chamber 112 is equipped with an ammonia decomposition catalyst 113, which is used to assist in the thermal decomposition of ammonia.

[0054] In this embodiment, the heating chamber 111 is provided with a fuel exhaust nozzle 114 and a first fuel exhaust outlet 115. The fuel exhaust nozzle 114 and the first fuel exhaust outlet 115 are respectively located at both ends of the heating chamber 111. The ammonia decomposition chamber 112 is provided with an ammonia decomposition gas outlet 116 and an ammonia gas inlet 117 to be decomposed. The ammonia gas inlet 117 to be decomposed is connected to the ammonia gas source 500. During operation, the ammonia gas to be decomposed enters from the ammonia gas inlet 117 to be decomposed. Under the heating of the ammonia decomposition chamber 112 by the heating chamber 111 and the catalytic action of the ammonia decomposition catalyst 113, the ammonia gas is decomposed into hydrogen and nitrogen.

[0055] The NOx decomposition system 200 of this embodiment includes a NOx decomposer 210, such as Figure 3 As shown, the NOx decomposer 210 is provided with a NOx decomposition chamber 211 and a combustion exhaust gas heating chamber 212 with a heat exchange relationship between the walls. The combustion exhaust gas heating chamber 212 is provided with a combustion exhaust gas inlet 213 and a second combustion exhaust gas outlet 214. The combustion exhaust gas inlet 213 is connected to the first fuel exhaust gas outlet 115 of the heating chamber 111, and the second combustion exhaust gas outlet 214 is connected to the outside. The NOx decomposition chamber 211 is provided with an engine exhaust gas inlet 215, a combustion-supporting exhaust gas outlet 216, and a NOx decomposition catalyst 217 filled inside the NOx decomposition chamber 211. The NOx decomposition catalyst 217 is used to decompose N2O and NO2 in nitrogen oxides into NO by endothermic catalytic decomposition.

[0056] The ammonia-hydrogen engine 600 of this embodiment is provided with an engine fuel input end 610 and an engine exhaust gas output end 620. The engine exhaust gas output end 620 is connected to the engine exhaust gas inlet 215 of the NOx decomposition chamber 211, while the engine fuel input end 610 is connected to the ammonia decomposition gas output outlet 116 of the ammonia decomposition chamber 112. The hydrogen gas decomposed by the ammonia decomposition chamber 112 is transported to the engine fuel input end 610. At the same time, the engine fuel input end 610 is connected to the ammonia gas source 500 through a pipeline to ensure a stable supply of ammonia gas and ensure the efficient operation of the ammonia-hydrogen engine 600.

[0057] The NOx decomposition catalyst 217 is uniformly filled inside the cavity, ensuring full contact between the engine exhaust gas and the catalyst, maximizing the decomposition reaction of nitrogen oxides. Under the action of the catalyst, nitrogen oxides are decomposed, and then the generated combustion exhaust gas is delivered to the next stage of the system through the combustion exhaust gas outlet 216, realizing efficient treatment of exhaust gas and reuse of energy.

[0058] like Figure 4 As shown, the flameless combustion system 300 of this embodiment includes a furnace body 310 and an ignition device 320. The furnace body 310 is provided with a combustion chamber 311 and a preheating and cooling chamber 312 with a heat exchange relationship between the walls. In order to improve the efficiency of heat exchange, the preheating and cooling chamber 312 is wrapped around the outside of the combustion chamber 311. It can be understood that the furnace body 310 of this embodiment includes an inner wall and an outer wall. The combustion chamber 311 is formed in the inner wall, while the preheating and cooling chamber 312 is formed between the inner wall and the outer wall.

[0059] An ammonia combustion catalyst 319 is provided inside the preheating and cooling chamber 312. The ammonia combustion catalyst 319 can reduce the combustion temperature of the fuel, enabling the fuel to burn fully at a lower temperature, improving combustion efficiency, reducing the generation of unburned residues, rapidly increasing the furnace wall temperature, and significantly shortening the time required for the combustion chamber 311 to reach the start-up temperature. It can quickly enter the flameless combustion state while controlling the combustion temperature.

[0060] In this embodiment, the combustion chamber 311 is provided with an ammonia combustion nozzle 313, an air jet port 314, and an exhaust port 315. The air jet port 314 and the ammonia combustion nozzle 313 are respectively located on two opposite inner sides of the combustion chamber 311. The exhaust port 315 and the air jet port 314 are located on the same side of the combustion chamber 311. The air jet port 314 is connected to the preheating and cooling chamber 312. The exhaust port 315 is connected to the fuel exhaust nozzle 114 of the heating chamber 111. The preheating and cooling chamber 312 is provided with a combustion-supporting mixture port 316. The ignition device 320 is located in the preheating and cooling chamber 312. The combustion-supporting mixture port 316 is connected to the combustion-supporting exhaust gas output port 216 of the NOx decomposition chamber 211, the air source 400, and the ammonia source 500, respectively. The ammonia combustion nozzle 313 is connected to the ammonia source 500. The preheating and cooling chamber 312 is provided with an ammonia combustion catalyst 319.

[0061] In flameless combustion, the combustion mixture is injected into the combustion chamber 311 through the air jet port 314 and mixes with the fuel ejected from the ammonia combustion nozzle 313 to form a uniform combustion flow field. The air jet port 314 and the exhaust gas outlet 315 are located on the same side of the combustion chamber 311. The exhaust gas flows in the opposite direction to the high-velocity air jet, which increases the residence time of the combustion gas flow. The air is first fully mixed with the combustion exhaust gas to reduce the oxygen concentration before mixing with the fuel, which effectively reduces the combustion rate and better maintains the flameless combustion state.

[0062] During cold start, the combustion mixture of combustion exhaust gas, air, and ammonia is introduced into the preheating and cooling chamber 312 through the combustion mixture port 316. The combustion mixture is ignited by the ignition device 320, and the heat generated is used to preheat the walls of the combustion chamber 311. At this time, the combustion exhaust gas passes sequentially through the air jet port 314, the combustion chamber 311, the heating chamber 111, and the combustion exhaust gas heating chamber 212 to preheat the components in the ammonia decomposition system 100 and the NOx decomposition system 200. Once the walls of the combustion chamber 311 are heated to the target temperature for flameless combustion, ammonia gas is injected into the combustion chamber 312 through the ammonia combustion nozzle 313. 11. Simultaneously, the combustion exhaust gas and air are mixed and injected into the combustion chamber 311 after passing through the preheating and cooling chamber 312. This allows the fuel and air to undergo counter-current mixing and combustion within the combustion chamber 311, enabling rapid startup of the flameless combustion furnace. The combustion exhaust gas passes sequentially through the heating chamber 111 and the combustion exhaust gas heating chamber 212, providing heat for ammonia decomposition and NOx decomposition. At this time, the preheating and cooling chamber 312 only introduces the combustion exhaust gas and air. The combustion exhaust gas and air flow over the preheated wall surface, absorb heat, and are then injected into the combustion chamber 311, thus protecting the wall surface of the combustion chamber 311 from direct impact by the high-temperature flame and achieving the function of cooling the wall surface. Meanwhile, the air in the preheating and cooling chamber 312 will return the absorbed heat to the combustion chamber 311, improving the heat utilization rate, maintaining the high-temperature environment in the combustion chamber 311, and ensuring the continuous flameless combustion. Through the design of the preheating and cooling chamber 312, the combustion furnace can preheat the wall surface on its own during the start-up phase without the need for additional preheating equipment or energy input. This simplifies the system structure, improves preheating efficiency, shortens preheating time, and provides rapid and effective preparation conditions for the stable operation of flameless combustion.

[0063] During the start-up phase, the ammonia-hydrogen internal combustion engine and the preheating and cooling chamber 312 of the flameless combustion system 300 are simultaneously ignited. The preheating and cooling chamber 312 rapidly heats the inner wall of the combustion chamber 311 to the temperature required for flameless combustion. The exhaust gas produced by combustion further preheats the various components of the ammonia decomposition system 100 and the NOx decomposition system 200, improving the response speed during the start-up phase. During normal operation, the temperature of the inner wall of the combustion chamber 311 reaches the temperature required for flameless combustion. By changing the flow path of ammonia, ammonia is introduced into the combustion chamber 311 to start flameless combustion. The high-temperature combustion exhaust gas produced by flameless combustion is sequentially introduced into the heating chamber 111 and the combustion exhaust gas heating chamber 212 to heat the ammonia decomposition chamber 112. Under the action of the ammonia decomposition catalyst 113, the ammonia in the ammonia decomposition chamber 112 is decomposed into hydrogen. The ammonia decomposition chamber 211 is also heated, and under the action of the NOx decomposition catalyst 217, the NOx in the engine exhaust gas is decomposed into NO. The combustion chamber generates combustion exhaust gas, which is mixed with a set amount of air to form a combustion mixture with a set oxygen concentration. This mixture is preheated in a preheating and cooling chamber 312 and then injected into the combustion chamber 311, where it mixes with ammonia for flameless combustion. This further assists in flameless combustion, suppressing NOx formation and producing high-temperature combustion exhaust gas. The heat also heats the ammonia decomposition chamber 112 and the NOx decomposition chamber 211. This not only utilizes the nitrogen oxides produced by the ammonia-hydrogen engine 600 but also, through optimized combustion technology, produces almost no additional nitrogen oxide emissions. Simultaneously, the combustion mixture in the preheating and cooling chamber 312 returns the absorbed heat to the combustion chamber 311, improving heat utilization and maintaining a high-temperature environment within the combustion chamber 311, ensuring continuous flameless combustion. No additional preheating equipment or energy input is required, simplifying the system structure, improving preheating efficiency, and shortening preheating time, providing rapid and effective preparation conditions for stable flameless combustion.

[0064] In this embodiment, an ammonia decomposition gas compressor 700 and a high-pressure hydrogen buffer tank 710 are sequentially arranged between the outlet of the ammonia decomposition chamber 112 and the engine fuel input end 610 to achieve efficient matching between the ammonia decomposition chamber 112 and the ammonia-hydrogen engine 600 under varying operating conditions. The introduction of the high-pressure hydrogen buffer tank 710 can stabilize the hydrogen supply flow rate, ensuring that the ammonia-hydrogen engine 600 can obtain sufficient hydrogen support under various operating conditions, while effectively alleviating the problem of unstable hydrogen supply caused by demand fluctuations. During the start-up phase of the ammonia-hydrogen internal combustion engine, the ammonia-hydrogen internal combustion engine first uses the gas in the high-pressure decomposition gas buffer tank to meet the second-level start-up of the internal combustion engine.

[0065] In this embodiment, an air compressor 800 and an air flow controller 810 are sequentially arranged between the air source 400 and the combustion mixture port 316, and a combustion gas flow detector 900 is arranged between the NOx decomposition chamber 211 and the combustion gas port 316. The combustion gas flow detector 900 is used to monitor the combustion gas flow and generate data, and controls the oxygen concentration in the combustion mixture according to the combustion gas flow. The air compressor 800 is used to increase the air pressure to ensure that air can effectively enter the high-pressure combustion gas path. The air flow controller 810 is used to receive the data from the combustion gas flow detector 900 and adjust the air flow according to the data.

[0066] Since there is no oxygen in the exhaust gas of an internal combustion engine, when the internal combustion engine is under high operating conditions, the exhaust gas flow rate increases by nearly 10 times and is mixed with air before being introduced into the flameless combustion system 300. At this time, in order to ensure the stability of flameless combustion, it is necessary to increase the air flow rate to ensure that the oxygen concentration in the mixed gas is between 5-15%.

[0067] Furthermore, in this embodiment, the preheating and cooling chamber 312 is provided with multiple heat-conducting fins extending along the airflow direction. The multiple heat-conducting fins are arranged in a ring at intervals. The heat-conducting fins are connected to the outer peripheral wall of the combustion chamber 311 and the inner peripheral wall of the preheating and cooling chamber 312. The ammonia combustion catalyst 319 is coated on the surface of the heat-conducting fins. The heat-conducting fins can improve the overall structural strength of the furnace body 310 and increase the heat exchange area, thereby improving the heating efficiency in the preheating stage and the cooling effect in the flameless combustion stage.

[0068] A first fuel control valve 317 is provided between the ammonia source 500 and the combustion mixing port 316 to control the on / off state between the ammonia source 500 and the combustion mixing port 316. A second fuel control valve 318 is provided between the ammonia source 500 and the ammonia combustion nozzle 313 to control the on / off state between the ammonia source 500 and the ammonia combustion nozzle 313.

[0069] The ammonia decomposition chamber 112 is provided with multiple decomposition guide vanes, which are arranged alternately and staggered along the airflow direction to form a serpentine decomposition baffle channel. The ammonia decomposition catalyst 113 is filled in the decomposition baffle channel.

[0070] In this embodiment, a combustion-supporting exhaust gas valve 218 is provided between the combustion-supporting exhaust gas outlet 216 and the combustion-supporting mixed gas outlet 316 to control the flow rate of the combustion-supporting exhaust gas.

[0071] Furthermore, this invention also proposes an operating method applicable to ammonia-hydrogen engine systems, such as... Figure 5 As shown, the operation method includes:

[0072] Step S100: During the start-up phase of the ammonia-hydrogen engine 600, the ammonia-hydrogen engine 600 is started, and the engine exhaust gas enters the preheating and cooling chamber 312. At the same time, ammonia and air are introduced into the preheating and cooling chamber 312 according to the first preset ammonia supply and the first preset air supply. Ignition is performed by the ignition device 320, and a combustion reaction occurs in the preheating and cooling chamber 312 under the action of the ammonia combustion catalyst 319. The preheating and cooling chamber 312 heats the combustion chamber 311, and the exhaust gas generated by combustion preheats the ammonia decomposer 110 and the NOx decomposer 210.

[0073] Step S200: After the ammonia-hydrogen internal combustion engine has been running for a predetermined time, the temperature of the inner wall of the combustion chamber 311 reaches the temperature required for flameless combustion. Ammonia gas is introduced into the combustion chamber 311 according to the second set ammonia supply rate, and the supply of ammonia gas to the preheating and cooling chamber 312 is stopped. Flameless combustion is started, and ammonia gas is introduced into the ammonia decomposition chamber 112 according to the third set ammonia supply rate. The high-temperature combustion exhaust gas generated by combustion is introduced into the heating chamber 111 to heat the ammonia decomposition chamber 112. Under the action of the ammonia decomposition catalyst 113, the ammonia gas in the ammonia decomposition chamber 112 is heated. The gas is decomposed into hydrogen and supplied to the ammonia-hydrogen engine 600 for combustion. The engine exhaust gas generated by the ammonia-hydrogen engine 600 is passed into the NOx decomposition chamber 211. The high-temperature exhaust gas after passing through the heating chamber 111 is passed into the combustion exhaust gas heating chamber 212 to heat the NOx decomposition chamber 211. Under the action of the NOx decomposition catalyst 217, the NOx in the engine exhaust gas is decomposed into NO to form combustion-supporting exhaust gas. The combustion-supporting exhaust gas is passed into the preheating and cooling chamber 312 to further assist flameless combustion.

[0074] Step S300: When the ammonia-hydrogen internal combustion engine changes from a low operating condition to a high operating condition, the amount of air introduced into the preheating and cooling chamber 312 is controlled by detecting the flow rate of the combustion exhaust gas, so as to control the oxygen concentration in the preheating and cooling chamber 312 and achieve stable flameless combustion.

[0075] This invention utilizes a three-catalytic converter system to achieve ammonia-hydrogen internal combustion engine systems, using ammonia as the sole fuel source. This system satisfies the ammonia-hydrogen mixed combustion requirement of the engine, where ammonia is the primary fuel and hydrogen obtained from the decomposition of ammonia serves as the combustion-supporting gas. The mixing of these two components ensures the stable and efficient operation of the internal combustion engine. Furthermore, the flameless combustion system 300 enables the effective recycling of heat. In addition, the NO carried by the combustion-supporting exhaust gas helps to form stable flameless combustion, thus addressing the variable operating conditions of the vehicle's internal combustion engine system and meeting the requirements for second-level start-up and rapid response.

[0076] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0077] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A catalytic combustion-assisted preheating ammonia-hydrogen engine system, characterized in that, include: An ammonia decomposition system includes an ammonia decomposer, wherein the ammonia decomposer is provided with a heating chamber and an ammonia decomposition chamber having a heat exchange relationship between the walls, and the ammonia decomposition chamber is provided with an ammonia decomposition catalyst; The NOx decomposition system includes a NOx decomposer, which has a NOx decomposition chamber and a combustion exhaust gas heating chamber with a heat exchange relationship between the two walls. The heating chamber is connected to the combustion exhaust gas heating chamber. The combustion exhaust gas heating chamber has a second combustion exhaust gas outlet connected to the outside. The NOx decomposition chamber is equipped with a NOx decomposition catalyst. An ammonia-hydrogen engine is provided with an engine fuel input end and an engine exhaust gas output end. The engine exhaust gas output end is connected to the NOx decomposition chamber, and the engine fuel input end is connected to the ammonia decomposition chamber. A flameless combustion system includes a furnace body and an ignition device. The furnace body has a combustion chamber and a preheating and cooling chamber with a heat exchange relationship between the walls. The preheating and cooling chamber contains an ammonia combustion catalyst. The combustion chamber has an ammonia combustion nozzle, an air jet port, and a tail gas exhaust port. The air jet port and the ammonia combustion nozzle are respectively located on two opposite inner sides of the combustion chamber. The tail gas exhaust port and the air jet port are located on the same side of the combustion chamber. The air jet port is connected to the preheating and cooling chamber. The tail gas exhaust port is connected to the heating chamber. The preheating and cooling chamber has a combustion-supporting gas port. The ignition device is located in the preheating and cooling chamber. The combustion-supporting gas port is connected to the NOx decomposition chamber. An air source is connected to the combustion-supporting gas mixing port; The ammonia gas source is connected to the ammonia decomposition chamber, the ammonia combustion nozzle, the combustion-supporting mixture port, and the engine fuel input terminal, respectively.

2. The ammonia-hydrogen engine system according to claim 1, characterized in that: An ammonia decomposition chamber outlet and an ammonia decomposition gas compressor and a high-pressure hydrogen buffer tank are sequentially provided between the engine fuel input end and the outlet of the ammonia decomposition chamber.

3. The ammonia-hydrogen engine system according to claim 2, characterized in that: A combustion-supporting gas flow detector is provided between the NOx decomposition chamber and the combustion-supporting gas mixing port.

4. The ammonia-hydrogen engine system according to claim 1, characterized in that: An air compressor and an air flow controller are sequentially installed between the air source and the combustion-supporting gas mixing port.

5. The ammonia-hydrogen engine system according to claim 1, characterized in that: The preheating and cooling chamber is wrapped around the outside of the combustion chamber.

6. The ammonia-hydrogen engine system according to claim 5, characterized in that: The preheating and cooling chamber is provided with multiple heat-conducting fins extending along the airflow direction. The multiple heat-conducting fins are arranged in a ring with intervals. The heat-conducting fins are connected to the outer peripheral wall of the combustion chamber and the inner peripheral wall of the preheating and cooling chamber. The ammonia combustion catalyst is coated on the surface of the heat-conducting fins.

7. The ammonia-hydrogen engine system according to claim 1, characterized in that: A first fuel control valve is provided between the ammonia source and the combustion-supporting gas mixing port; A second fuel control valve is provided between the ammonia gas source and the ammonia combustion nozzle.

8. The ammonia-hydrogen engine system according to claim 1, characterized in that: The ammonia decomposition chamber is arranged around the outer periphery of the heating chamber.

9. The ammonia-hydrogen engine system according to claim 8, characterized in that: The ammonia decomposition chamber is provided with multiple decomposition guide vanes, which are arranged in an alternating staggered manner along the airflow direction to form a serpentine decomposition baffle channel, and the ammonia decomposition catalyst is filled in the decomposition baffle channel.

10. A method for operating an ammonia-hydrogen engine system, characterized in that, It is applicable to the ammonia-hydrogen engine system as described in any one of claims 1 to 9, wherein the operating method includes: During the start-up phase of the ammonia-hydrogen engine, the ammonia-hydrogen engine is started, and the engine exhaust gas enters the preheating and cooling chamber. At the same time, ammonia and air are introduced into the preheating and cooling chamber according to the first preset ammonia supply and the first preset air supply. Ignition is performed by the ignition device, and a combustion reaction occurs in the preheating and cooling chamber under the action of the ammonia combustion catalyst. The preheating and cooling chamber heats the combustion chamber, and the exhaust gas generated by combustion preheats the ammonia decomposer and the NOx decomposer. After the ammonia-hydrogen engine has been running for a predetermined time, the temperature of the inner wall of the combustion chamber reaches the temperature required for flameless combustion. Ammonia is then introduced into the combustion chamber according to the second ammonia supply rate, and the supply of ammonia to the preheating and cooling chamber is stopped. Flameless combustion is then initiated. Ammonia is then introduced into the ammonia decomposition chamber according to the third ammonia supply rate. The high-temperature combustion exhaust gas generated by the combustion is introduced into the heating chamber to heat the ammonia decomposition chamber. Under the action of the ammonia decomposition catalyst, the ammonia in the ammonia decomposition chamber is decomposed into hydrogen, which is then supplied to the ammonia-hydrogen engine for combustion support. The engine exhaust gas generated by the ammonia-hydrogen engine is introduced into the NOx decomposition chamber. The high-temperature exhaust gas that has passed through the heating chamber is introduced into the combustion exhaust gas heating chamber to heat the NOx decomposition chamber. Under the action of the NOx decomposition catalyst, the NOx in the engine exhaust gas is decomposed into NO to form combustion support exhaust gas. The combustion support exhaust gas is then introduced into the preheating and cooling chamber to further assist flameless combustion. When the ammonia-hydrogen engine switches from low operating condition to high operating condition, the amount of air introduced into the preheating and cooling chamber is controlled by detecting the flow rate of the combustion exhaust gas, so as to control the oxygen concentration in the preheating and cooling chamber and achieve stable flameless combustion.

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