Catalytic combustion auxiliary preheating ammonia hydrogen engine system and operation method

Abstract

The invention discloses a catalytic combustion auxiliary preheating ammonia-hydrogen engine system and an operation method, the catalytic combustion auxiliary preheating ammonia-hydrogen engine system comprises an ammonia decomposition system, a NOx decomposition system, an ammonia-hydrogen engine, a flameless combustion system, an air source and an ammonia gas source, a preheating cooling cavity rapidly heats the inner wall surface of a combustion cavity to reach the temperature required by flameless combustion; tail gas generated by combustion further preheats all parts of the ammonia decomposition system and the NOx decomposition system, the response speed in the starting stage is increased, and in the normal operation stage, high-temperature combustion tail gas generated by flameless combustion is sequentially introduced into the heating cavity and the combustion tail gas heat supply cavity to heat the ammonia decomposition cavity so as to decompose ammonia gas in the ammonia decomposition cavity into hydrogen, and the hydrogen is converted into nitrogen; and the NOx decomposition cavity is heated to decompose NOx in the tail gas of the engine into NO, the combustion-supporting mixed gas is preheated through the preheating cooling cavity and then sprayed into the combustion cavity, the combustion-supporting mixed gas is mixed with ammonia gas for flameless combustion, and flameless combustion is further assisted.

Description

Technical Field

[0001] The present invention relates to the field of energy-saving and new energy vehicles, and particularly relates to an ammonia-hydrogen engine system with catalytic combustion-assisted preheating and an operation method thereof. Background Art

[0002] As a clean fuel, ammonia is considered to be the key to future energy transformation because it does not produce carbon dioxide during combustion, and has a high energy density and good storage and transportation characteristics. In order to reduce the impact of engines on the environment, ammonia-hydrogen engines have been developed by utilizing the combustion characteristics of ammonia and hydrogen, truly realizing a highly efficient, clean, and zero-carbon combustion engine. However, the direct combustion of ammonia will produce a large amount of nitrogen oxides (NOx); Existing exhaust gas treatment devices require additional heat and ammonia to provide working conditions for the devices, wasting the energy of the engine system and reducing the overall energy efficiency of the system. Although existing methods for recovering the heat of the engine's surplus gas have been provided, the role of NO in assisting the combustion of ammonia has not been considered, thus wasting the engine's surplus gas. Moreover, due to the low temperature of the engine's surplus gas, the efficiency of heat recovery and utilization is too low, and existing exhaust gas treatment devices cannot cope with the changing working conditions of in-vehicle internal combustion engine systems and cannot meet the rapid response of in-vehicle internal combustion engine systems. Summary of the Invention The purpose of the present invention is to provide an ammonia-hydrogen engine system with catalytic combustion-assisted preheating and an operation method thereof, so as to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

[0003] The technical solutions adopted to solve the above technical problems are as follows: The present invention provides an ammonia-hydrogen engine system with catalytic combustion-assisted preheating, including: An ammonia decomposition system, including an ammonia decomposer, the ammonia decomposer is provided with a heating chamber and an ammonia decomposition chamber having a partition heat exchange relationship, and the ammonia decomposition chamber is provided with an ammonia decomposition catalyst; A NOx decomposition system, including a NOx decomposer and an ammonia-hydrogen engine, the NOx decomposer is provided with a NOx decomposition chamber and a combustion exhaust gas heat supply chamber having a partition heat exchange relationship, the heating chamber is communicated with the combustion exhaust gas heat supply chamber, the combustion exhaust gas heat supply chamber is provided with a second combustion exhaust gas outlet communicated with the outside, and the NOx decomposition chamber is provided with a NOx decomposition catalyst; An ammonia-hydrogen engine, provided with an engine fuel input end and an engine exhaust gas output end, the engine exhaust gas output end is communicated with the NOx decomposition chamber, and the engine fuel input end is communicated with the ammonia decomposition chamber; The flameless combustion system includes a furnace body and an ignition device. The furnace body is provided with a combustion chamber and a preheating and cooling chamber having a partition heat exchange relationship. An ammonia combustion catalyst is provided inside the preheating and cooling chamber. The combustion chamber is provided with an ammonia combustion nozzle, an air jet port, and an exhaust gas discharge port. The air jet port and the ammonia combustion nozzle are respectively arranged on two opposite inner sides of the combustion chamber. The exhaust gas discharge port and the air jet port are located on the same side of the combustion chamber. The air jet port is communicated with the preheating and cooling chamber, and the exhaust gas discharge port is connected to the heating chamber. The preheating and cooling chamber is provided with a combustion-supporting mixture gas port, and the ignition device is arranged in the preheating and cooling chamber. The combustion-supporting mixture gas port is connected to the NOx decomposition chamber; An air source, connected to the combustion-supporting mixture gas port; An ammonia source, respectively connected to the ammonia decomposition chamber, the ammonia combustion nozzle, the combustion-supporting mixture gas port, and the engine fuel input end.

[0004] The beneficial effects of the ammonia-hydrogen engine system of the present invention are as follows: In the startup stage, the ammonia-hydrogen internal combustion engine and the preheating and cooling chamber of the flameless combustion system are ignited simultaneously. The preheating and cooling chamber rapidly heats up the inner wall surface of the combustion chamber and reaches the required temperature for flameless combustion. The exhaust gas generated by combustion further preheats the components of the ammonia decomposition system and the NOx decomposition system, improving the response speed in the startup stage. In the normal operation stage, the temperature of the inner wall of the combustion chamber reaches the required temperature for flameless combustion. By changing the flow path of ammonia, ammonia is introduced into the combustion chamber to start flameless combustion. The high-temperature combustion exhaust gas generated by flameless combustion is sequentially introduced into the heating chamber and the combustion exhaust gas heat supply chamber to heat the ammonia decomposition chamber, and under the action of the ammonia decomposition catalyst, the ammonia in the ammonia decomposition chamber is decomposed into hydrogen, and to heat the NOx decomposition chamber, 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 combustion-supporting exhaust gas is mixed with a set amount of air to form a combustion-supporting mixture gas with a set oxygen concentration. The combustion-supporting mixture gas is preheated through the preheating and cooling chamber and then sprayed into the combustion chamber and mixed with ammonia for flameless combustion, further assisting flameless combustion to inhibit the generation of NOx, and obtaining the high-temperature combustion exhaust gas and the heat for heating the ammonia decomposition chamber and the NOx decomposition chamber. Not only is the nitrogen oxide generated by the ammonia-hydrogen engine utilized, but also through the optimized combustion technology, almost no additional nitrogen oxide emissions are generated. At the same time, the combustion-supporting mixture gas in the preheating and cooling chamber returns the absorbed heat to the combustion chamber, improving the heat utilization rate, maintaining the high-temperature environment in the combustion chamber, ensuring the continuous progress of flameless combustion, without the need for additional preheating equipment or energy input, simplifying the system structure, improving the preheating efficiency, shortening the preheating time, and providing fast and effective preparation conditions for the stable progress of flameless combustion.

[0005] As a further improvement of the above technical solution, an ammonia decomposition gas compressor and a high-pressure hydrogen buffer tank are sequentially arranged between the outlet of the ammonia decomposition chamber and the engine fuel input end.

[0006] As a further improvement of the above technical solution, an auxiliary gas flow detector is arranged between the NOx decomposition chamber and the combustion-supporting mixed gas port.

[0007] As a further improvement of the above technical solution, an air compressor and an air flow controller are sequentially arranged between the air source and the combustion-supporting mixed gas port.

[0008] As a further improvement of the above technical solution, the preheating and cooling chamber is wrapped outside the combustion chamber.

[0009] As a further improvement of the above technical solution, the preheating and cooling chamber is provided with a plurality of heat-conducting fins extending along the gas flow direction. The plurality of heat-conducting fins are arranged at annular 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.

[0010] As a further improvement of the above technical solution, a first fuel control valve is arranged between the ammonia gas source and the combustion-supporting mixed gas port; A second fuel control valve is arranged between the ammonia gas source and the ammonia combustion nozzle.

[0011] As a further improvement of the above technical solution, the ammonia decomposition chamber is arranged around the outer periphery of the heating chamber.

[0012] As a further improvement of the above technical solution, the ammonia decomposition chamber is provided with a plurality of decomposition guide vanes. The plurality of decomposition guide vanes are arranged in an alternating and staggered manner along the gas flow direction to form a serpentine decomposition baffle channel. The ammonia decomposition catalyst is filled in the decomposition baffle channel.

[0013] In addition, the present invention also proposes an operation method, which is applicable to the ammonia-hydrogen engine system described above. The operation method includes: In the starting stage of the ammonia-hydrogen engine, start the ammonia-hydrogen engine. The engine exhaust gas enters the preheating and cooling chamber. At the same time, ammonia gas and air are introduced into the preheating and cooling chamber according to a first preset ammonia supply amount and a first preset air amount. Ignition is carried out through the ignition device, and under the action of the ammonia combustion catalyst, a combustion reaction occurs in the preheating and cooling chamber. 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 internal combustion engine runs for a predetermined time, the temperature of the inner wall of the combustion chamber reaches the required temperature for flameless combustion. Ammonia gas is introduced into the combustion chamber according to the second set ammonia supply amount, the ammonia gas supply to the preheating and cooling chamber is stopped, flameless combustion is started, ammonia gas is introduced into the ammonia decomposition chamber according to the third set ammonia supply amount, and the high-temperature combustion exhaust gas generated by combustion is introduced into the heating chamber to heat the ammonia decomposition chamber. Under the action of the ammonia decomposition catalyst, the ammonia gas in the ammonia decomposition chamber is decomposed into hydrogen gas, which is supplied to the ammonia-hydrogen engine for assisting combustion and working. The engine exhaust gas generated by the operation of the ammonia-hydrogen engine is introduced into the NOx decomposition chamber, and the high-temperature exhaust gas passing through the heating chamber is introduced into the combustion exhaust gas heat supply 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-supporting exhaust gas. The combustion-supporting exhaust gas is introduced into the preheating and cooling chamber to further assist flameless combustion; When the ammonia-hydrogen internal combustion engine changes from a low working condition to a high working condition, by detecting the flow rate of the combustion-supporting exhaust gas, the air volume introduced into the preheating and cooling chamber is controlled to control the oxygen concentration in the preheating and cooling chamber to achieve stable flameless combustion.

[0014] Other features and advantages of the present invention will be described in the following specification, and will, in part, be obvious from the specification, or will be understood by practicing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the drawings and embodiments; Figure 1 is a schematic structural diagram of an ammonia-hydrogen engine system provided by the present invention, showing an embodiment; Figure 2 is a schematic structural diagram of an ammonia decomposer provided by the present invention, showing an embodiment; Figure 3 is a schematic structural diagram of a NOx decomposer provided by the present invention, showing an embodiment; Figure 4 is a schematic structural diagram of a flameless combustion system provided by the present invention, showing an embodiment; Figure 5 is a control flowchart of an operation method provided by the present invention, showing an embodiment; Reference Numerals in the Drawings: 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 gas decomposition gas output port 116; Ammonia gas to be decomposed input port 117; NOx decomposition system 200; NOx decomposer 210; NOx decomposition chamber 211; combustion exhaust gas heating chamber 212; combustion exhaust gas input port 213; second combustion exhaust gas outlet 214; engine exhaust gas input port 215; combustion-supporting exhaust gas output port 216; NOx decomposition catalyst 217; combustion-supporting exhaust gas pipeline valve 218; 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 discharge port 315; combustion-supporting mixture gas port 316; first control valve 317; fuel second control valve 318; ammonia combustion catalyst 319; ignition device 320; Air source 400; Ammonia source 500; Ammonia-hydrogen engine 600; engine fuel input end 610; engine exhaust gas output end 620; Ammonia decomposition gas compressor 700; high-pressure hydrogen storage tank 710; Air compressor 800; air flow controller 810; Combustion-supporting gas flow detector 900. Detailed implementation mode

[0016] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0017] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as up and down, etc., is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0018] In the description of the present invention, "a plurality of" refers to more than two. If the first and second are described only for the purpose of distinguishing technical features, it should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0019] In the description of the present invention, unless otherwise clearly defined, words such as "set", "installed", "connected", 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.

[0020] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0021] As Figures 1 to 4 shown, a catalytic combustion-assisted preheating ammonia-hydrogen engine system of 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.

[0022] Among them, the ammonia source 500 is used to supply ammonia, and the air source 400 is used to supply air.

[0023] Among them, the ammonia decomposition system 100 includes an ammonia decomposer 110. As Figure 2 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 partition heat exchange relationship. In order to improve the heat exchange efficiency between the heating chamber 111 and the ammonia decomposition chamber 112, the ammonia decomposition chamber 112 of this embodiment is arranged around the outer periphery of the heating chamber 111.

[0024] The ammonia decomposition chamber 112 of this embodiment is provided with an ammonia decomposition catalyst 113, and the ammonia decomposition catalyst 113 is used to assist the thermal decomposition of ammonia.

[0025] The heating chamber 111 of this embodiment is provided with a fuel exhaust gas nozzle 114 and a first fuel exhaust gas outlet 115. The fuel exhaust gas nozzle 114 and the first fuel exhaust gas outlet 115 are respectively arranged at both ends of the heating chamber 111, and the ammonia decomposition chamber 112 is provided with an ammonia decomposition gas output port 116 and an ammonia to be decomposed input port 117. The ammonia to be decomposed input port 117 is connected to the ammonia source 500. During operation, the ammonia to be decomposed enters from the ammonia to be decomposed input port 117. Under the heating of the heating chamber 111 to the ammonia decomposition chamber 112 and the catalytic action of the ammonia decomposition catalyst 113, ammonia is decomposed into hydrogen and nitrogen.

[0026] The NOx decomposition system 200 of this embodiment includes a NOx decomposer 210. As Figure 3 shown, the NOx decomposer 210 is provided with a NOx decomposition chamber 211 and a combustion exhaust gas heating chamber 212 having a partition heat exchange relationship. The combustion exhaust gas heating chamber 212 is provided with a combustion exhaust gas input port 213 and a second combustion exhaust gas outlet 214. The combustion exhaust gas input port 213 is communicated with the first fuel exhaust gas outlet 115 of the heating chamber 111, and the second combustion exhaust gas outlet 214 is communicated with the outside. The NOx decomposition chamber 211 is provided with an engine exhaust gas input port 215, a combustion-supporting exhaust gas output port 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 means of endothermic catalytic decomposition.

[0027] 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 communicated with the engine exhaust gas input port 215 of the NOx decomposition chamber 211, while the engine fuel input end 610 is connected to the ammonia decomposition gas output port 116 of the ammonia decomposition chamber 112. The hydrogen 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, ensuring the stable supply of ammonia and guaranteeing the efficient operation of the ammonia-hydrogen engine 600.

[0028] The NOx decomposition catalyst 217 is uniformly filled inside the chamber, ensuring sufficient 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-supporting exhaust gas is transported to the next link of the system through the combustion-supporting exhaust gas output port 216, realizing the efficient treatment of exhaust gas and the reuse of energy.

[0029] As Figure 4 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 having a partition heat exchange relationship. In order to replace the thermal efficiency, the preheating and cooling chamber 312 is wrapped outside the combustion chamber 311. It can be understood that the furnace body 310 of this embodiment includes an inner wall body and an outer wall body. The combustion chamber 311 is formed inside the inner wall body, while the preheating and cooling chamber 312 is formed between the inner wall body and the outer wall body.

[0030] 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, enable the fuel to burn sufficiently at a lower temperature, improve the combustion efficiency, reduce the generation of unburned residues, rapidly increase the furnace wall temperature, greatly shorten the time required for the combustion chamber 311 to reach the starting temperature, and can quickly enter the flameless combustion state while controlling the combustion temperature.

[0031] The combustion chamber 311 of this embodiment is provided with an ammonia combustion nozzle 313, an air jet port 314, and an exhaust gas discharge port 315. The air jet port 314 and the ammonia combustion nozzle 313 are respectively arranged on two opposite inner sides of the combustion chamber 311. The exhaust gas discharge 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 communicated with the preheating and cooling chamber 312. The exhaust gas discharge port 315 is connected to the fuel exhaust gas nozzle 114 of the heating chamber 111. The preheating and cooling chamber 312 is provided with a combustion-supporting mixture gas port 316. The ignition device 320 is arranged in the preheating and cooling chamber 312. The combustion-supporting mixture gas port 316 is respectively 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. The ammonia combustion nozzle 313 is connected to the ammonia source 500. An ammonia combustion catalyst 319 is arranged inside the preheating and cooling chamber 312.

[0032] In flameless combustion, the combustion-supporting mixture gas is sprayed into the combustion chamber 311 through the air jet port 314 and mixed with the fuel sprayed out from the ammonia combustion nozzle 313 to form a uniform combustion flow field. The air jet port 314 and the exhaust gas discharge port 315 are located on the same side of the combustion chamber 311. The exhaust gas is in the opposite direction to the high-velocity air jet, which increases the residence time of the combustion airflow. The air is first fully mixed with the combustion exhaust gas, and after the oxygen concentration is reduced, it is mixed with the fuel, effectively reducing the combustion rate and better maintaining the flameless combustion state.

[0033] During cold start, the combustion-supporting mixed gas after mixing the combustion-supporting exhaust gas, air and ammonia is introduced into the preheating and cooling chamber 312 through the combustion-supporting mixed gas port 316, and the combustion-supporting mixed gas is ignited and burned by the ignition device 320. The generated heat is used to preheat the wall surface of the combustion chamber 311. At this time, the combustion exhaust gas sequentially passes through the air jet port 314, the combustion chamber 311, the heating chamber 111, and the combustion exhaust gas heat supply chamber 212 to preheat the components in the ammonia decomposition system 100 and the NOx decomposition system 200. When the wall surface of the combustion chamber 311 is heated to the target temperature of flameless combustion, ammonia is sprayed into the combustion chamber 311 through the ammonia combustion nozzle 313. At the same time, the combustion-supporting exhaust gas and air are mixed and sprayed into the combustion chamber 311 after passing through the preheating and cooling chamber 312, so that the fuel and air are subjected to counterflow mixing combustion in the combustion chamber 311 to quickly start the flameless combustion furnace. The combustion exhaust gas sequentially passes through the heating chamber 111 and the combustion exhaust gas heat supply chamber 212 to provide heat for ammonia decomposition and NOx decomposition. At this time, only the combustion-supporting exhaust gas and air are introduced into the preheating and cooling chamber 312. The combustion-supporting exhaust gas and air flow through the preheated wall surface, absorb heat and are sprayed into the combustion chamber 311, playing a role in protecting the wall surface of the combustion chamber 311 and preventing it from being directly impacted by the high-temperature flame, realizing the function of cooling the wall surface. At the same time, the air in the preheating and cooling chamber 312 returns the absorbed heat to the combustion chamber 311, improving the utilization rate of heat, maintaining the high-temperature environment in the combustion chamber 311, and ensuring the continuous progress of flameless combustion. Through the design of the preheating and cooling chamber 312 in the present invention, the combustion furnace can preheat the wall surface by itself during the start-up stage without additional preheating equipment or energy input, simplifying the system structure, improving the preheating efficiency, shortening the preheating time, and providing fast and effective preparation conditions for the stable progress of flameless combustion.

[0034] In the startup phase, the ammonia-hydrogen internal combustion engine and the preheating and cooling chamber 312 of the flameless combustion system 300 are ignited simultaneously. The preheating and cooling chamber 312 rapidly heats up the inner wall surface of the combustion chamber 311 to reach the required temperature for flameless combustion. The exhaust gas generated by combustion further preheats each component of the ammonia decomposition system 100 and the NOx decomposition system 200, improving the response speed in the startup phase. In the normal operation phase, the temperature of the inner wall of the combustion chamber 311 reaches the required temperature for flameless combustion. By changing the flow path of ammonia gas, ammonia gas is introduced into the combustion chamber 311 to initiate flameless combustion. The high-temperature combustion exhaust gas generated by flameless combustion is successively introduced into the heating chamber 111 and the combustion exhaust gas heat supply chamber 212, heating the ammonia decomposition chamber 112. Under the action of the ammonia decomposition catalyst 113, the ammonia gas in the ammonia decomposition chamber 112 is decomposed into hydrogen gas. And it heats the NOx decomposition chamber 211, and 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 mixed with a set amount of air to form a combustion-supporting mixture with a set oxygen concentration. The combustion-supporting mixture is preheated through the preheating and cooling chamber 312 and then injected into the combustion chamber 311, and is mixed with ammonia gas for flameless combustion, further assisting flameless combustion to inhibit the generation of NOx, and obtaining the high-temperature combustion exhaust gas and the heat for heating the ammonia decomposition chamber 112 and the NOx decomposition chamber 211. Not only is the nitrogen oxide generated by the ammonia-hydrogen engine 600 utilized, but also through the optimized combustion technology, almost no additional nitrogen oxide emissions are produced. At the same time, the combustion-supporting mixture in the preheating and cooling chamber 312 returns the absorbed heat to the combustion chamber 311, improving the heat utilization rate, maintaining the high-temperature environment in the combustion chamber 311, ensuring the continuous progress of flameless combustion, without the need for additional preheating equipment or energy input, simplifying the system structure, improving the preheating efficiency, shortening the preheating time, and providing rapid and effective preparation conditions for the stable progress of flameless combustion.

[0035] In this embodiment, an ammonia decomposition gas compressor 700 and a high-pressure hydrogen buffer tank 710 are successively 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 variable working conditions. The introduction of the high-pressure hydrogen buffer tank 710 can stabilize the hydrogen supply flow rate, ensure that the ammonia-hydrogen engine 600 can obtain sufficient hydrogen support under various working conditions, and at the same time effectively alleviate the problem of unstable hydrogen supply caused by demand fluctuations. In the startup 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 startup of the internal combustion engine.

[0036] In this embodiment, an air compressor 800, an air flow controller 810 are sequentially arranged between the air source 400 and the combustion-supporting mixed gas port 316, and a combustion-supporting gas flow detector 900 is arranged between the NOx decomposition chamber 211 and the combustion-supporting mixed gas port 316. The combustion-supporting gas flow detector 900 is used to monitor the combustion-supporting gas flow and generate data, and control the oxygen concentration in the combustion-supporting mixed gas according to the combustion-supporting gas flow. The air compressor 800 is used to increase the air pressure to ensure that air can effectively enter the combustion-supporting mixed gas gas path with a higher pressure. The air flow controller 810 is used to receive the data of the combustion-supporting gas flow detector 900 and regulate the air flow according to this data.

[0037] Since there is no oxygen in the internal combustion engine exhaust gas, when the internal combustion engine is in a high working condition, the exhaust gas flow increases by nearly 10 times and is mixed with air and then introduced into the flameless combustion system 300 together. At this time, in order to ensure the stability of flameless combustion, it is necessary to increase the air flow to ensure that the oxygen concentration in the mixed gas is between 5% and 15%.

[0038] Furthermore, the preheating and cooling chamber 312 of this embodiment is provided with a plurality of heat-conducting fins extending along the air flow direction. The plurality of heat-conducting fins are arranged at annular 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. On the one hand, the heat-conducting fins can improve the overall structural strength of the furnace body 310, and on the other hand, increase the heat exchange area, improve the heating efficiency in the preheating stage and the cooling effect in the flameless combustion stage.

[0039] A first fuel control valve 317 is arranged between the ammonia source 500 and the combustion-supporting mixed gas port 316 to control the on-off between the ammonia source 500 and the combustion-supporting mixed gas port 316. A second fuel control valve 318 is arranged between the ammonia source 500 and the ammonia combustion nozzle 313 to control the on-off between the ammonia source 500 and the ammonia combustion nozzle 313.

[0040] The ammonia decomposition chamber 112 is provided with a plurality of decomposition guide vanes. The plurality of decomposition guide vanes are arranged in an alternating and staggered manner along the air flow direction to form a serpentine decomposition baffle channel. The ammonia decomposition catalyst 113 is filled in the decomposition baffle channel.

[0041] In this embodiment, a combustion-supporting exhaust gas path valve 218 is arranged between the combustion-supporting exhaust gas output port 216 and the combustion-supporting mixed gas port 316 to control the flow of the combustion-supporting exhaust gas.

[0042] In addition, the present invention also proposes an operating method, which is applicable to an ammonia-hydrogen engine system, as Figure 5 shown. The operating method includes: Step S100: During the startup phase of the ammonia-hydrogen engine 600, start the ammonia-hydrogen engine 600. 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 amount and the first preset air amount. Ignition is carried out through the ignition device 320, and under the action of the ammonia combustion catalyst 319, a combustion reaction occurs in the preheating and cooling chamber 312. 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; Step S200: After the ammonia-hydrogen internal combustion engine has run for a predetermined time, the temperature of the inner wall of the combustion chamber 311 reaches the required temperature for flameless combustion. Ammonia is introduced into the combustion chamber 311 according to the second preset ammonia supply amount, and the supply of ammonia to the preheating and cooling chamber 312 is stopped. Flameless combustion is started. Ammonia is introduced into the ammonia decomposition chamber 112 according to the third preset ammonia supply amount. 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 in the ammonia decomposition chamber 112 is decomposed into hydrogen, which is supplied to the ammonia-hydrogen engine 600 for auxiliary combustion and work. The engine exhaust gas generated by the operation of the ammonia-hydrogen engine 600 is introduced into the NOx decomposition chamber 211, and the high-temperature exhaust gas passing through the heating chamber 111 is introduced into the combustion exhaust gas heat supply 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 auxiliary combustion exhaust gas, and the auxiliary combustion exhaust gas is introduced into the preheating and cooling chamber 312 to further assist flameless combustion; Step S300: When the ammonia-hydrogen internal combustion engine changes from a low operating condition to a high operating condition, by detecting the flow rate of the auxiliary combustion exhaust gas, control the air amount introduced into the preheating and cooling chamber 312 to control the oxygen concentration in the preheating and cooling chamber 312 to achieve stable flameless combustion.

[0043] The present invention realizes the ammonia-hydrogen mixed combustion of an ammonia-hydrogen internal combustion engine system using ammonia as a single fuel source through a three-catalyst system. Among them, ammonia is the main fuel, and the hydrogen obtained by decomposing ammonia is the combustion-supporting gas for the main fuel. Mixing the two can ensure the stable and efficient operation of the internal combustion engine. The flameless combustion system 300 realizes the effective recycling of heat. In addition, the NO carried by the auxiliary combustion exhaust gas helps to form stable flameless combustion to cope with the changing operating conditions of the vehicle-mounted internal combustion engine system and meet the second-level startup and rapid response of the vehicle-mounted internal combustion engine system.

[0044] In the description of this specification, the descriptions referring to the terms "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0045] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. An ammonia-hydrogen engine system with catalytic combustion assisted preheating, characterized in that, Comprising: An ammonia decomposition system, including an ammonia decomposer, the ammonia decomposer being provided with a heating chamber and an ammonia decomposition chamber having a partition heat exchange relationship, the ammonia decomposition chamber being provided with an ammonia decomposition catalyst; A NOx decomposition system, including a NOx decomposer, the NOx decomposer being provided with a NOx decomposition chamber and a combustion exhaust gas heating chamber having a partition heat exchange relationship, the heating chamber being communicated with the combustion exhaust gas heating chamber, the combustion exhaust gas heating chamber being provided with a second combustion exhaust gas outlet communicated with the outside, the NOx decomposition chamber being provided with a NOx decomposition catalyst; An ammonia-hydrogen engine, provided with an engine fuel input end and an engine exhaust gas output end, the engine exhaust gas output end being communicated with the NOx decomposition chamber, the engine fuel input end being communicated with the ammonia decomposition chamber; A flameless combustion system, including a furnace body and an ignition device, the furnace body being provided with a combustion chamber and a preheating and cooling chamber having a partition heat exchange relationship, the preheating and cooling chamber being internally provided with an ammonia combustion catalyst, the combustion chamber being provided with an ammonia combustion nozzle, an air jet port and an exhaust gas discharge port, the air jet port and the ammonia combustion nozzle being respectively arranged on two opposite inner sides of the combustion chamber, the exhaust gas discharge port and the air jet port being located on the same side of the combustion chamber, the air jet port being communicated with the preheating and cooling chamber, the exhaust gas discharge port being connected with the heating chamber, the preheating and cooling chamber being provided with a combustion-supporting mixed gas port, the ignition device being arranged in the preheating and cooling chamber, the combustion-supporting mixed gas port being connected with the NOx decomposition chamber; An air source, connected with the combustion-supporting mixed gas port; An ammonia gas source, respectively connected with the ammonia decomposition chamber, the ammonia combustion nozzle, the combustion-supporting mixed gas port and the engine fuel input end.

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

3. The ammonia-hydrogen engine system according to claim 2, wherein: A combustion-supporting gas flow detector is arranged between the NOx decomposition chamber and the combustion-supporting mixed gas port.

4. The ammonia-hydrogen engine system according to claim 1, wherein: An air compressor and an air flow controller are sequentially arranged between the air source and the combustion-supporting mixed gas port.

5. The ammonia-hydrogen engine system according to claim 1, wherein: The preheating and cooling chamber is wrapped outside the combustion chamber.

6. The ammonia-hydrogen engine system according to claim 5, wherein: The preheating and cooling chamber is provided with a plurality of heat conducting fins extending along the air flow direction, the plurality of heat conducting fins being arranged at annular intervals, the heat conducting fins being connected to the outer peripheral wall of the combustion chamber and the inner peripheral wall of the preheating and cooling chamber, and the ammonia combustion catalyst being coated on the surface of the heat conducting fins.

7. The ammonia-hydrogen engine system according to claim 1, wherein: A first fuel control valve is arranged between the ammonia gas source and the combustion-supporting mixed gas port; A second fuel control valve is arranged between the ammonia gas source and the ammonia combustion nozzle.

8. The ammonia-hydrogen engine system according to claim 1, wherein: 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 a plurality of decomposition guide vanes, and the plurality of decomposition guide vanes are arranged in an alternating staggered manner along the gas flow direction to form a serpentine decomposition baffle channel, and the ammonia decomposition catalyst is filled in the decomposition baffle channel.

10. A running method, characterized in that, It is applicable to the ammonia-hydrogen engine system according to any one of claims 1 to 9, and the operation method includes: In the starting stage of the ammonia-hydrogen engine, start the ammonia-hydrogen engine, and the engine exhaust gas enters the preheating and cooling chamber. At the same time, ammonia gas and air are introduced into the preheating and cooling chamber according to a first preset ammonia supply amount and a first preset air amount, and ignition is carried out through the ignition device. Under the action of the ammonia combustion catalyst, a combustion reaction occurs in the preheating and cooling chamber, and 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 internal combustion engine operates for a predetermined time, the temperature of the inner wall of the combustion chamber reaches the required temperature for flameless combustion. Ammonia gas is introduced into the combustion chamber according to a second preset ammonia supply amount, the ammonia gas supply to the preheating and cooling chamber is stopped, flameless combustion is started, ammonia gas is introduced into the ammonia decomposition chamber according to a third preset ammonia supply amount, and the high-temperature combustion exhaust gas generated by combustion is introduced into the heating chamber to heat the ammonia decomposition chamber. Under the action of the ammonia decomposition catalyst, the ammonia gas in the ammonia decomposition chamber is decomposed into hydrogen gas, which is supplied to the ammonia-hydrogen engine for auxiliary combustion work. The engine exhaust gas generated by the operation of the ammonia-hydrogen engine is introduced into the NOx decomposition chamber, and the high-temperature exhaust gas passing through the heating chamber is introduced into the combustion exhaust gas heat supply 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 auxiliary combustion exhaust gas, and the auxiliary combustion exhaust gas is introduced into the preheating and cooling chamber to further assist flameless combustion; When the ammonia-hydrogen internal combustion engine changes from a low working condition to a high working condition, by detecting the flow rate of the auxiliary combustion exhaust gas, the air amount introduced into the preheating and cooling chamber is controlled to control the oxygen concentration in the preheating and cooling chamber to achieve stable flameless combustion.

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