Ammonia fuel internal combustion engine and control method

Abstract

The invention discloses an ammonia fuel internal combustion engine and a control method, and belongs to the technical field of internal combustion engine structures, the ammonia fuel internal combustion engine comprises a cylinder body, a first nozzle and a spark plug, the cylinder body comprises a shell and a piston, a cavity is formed in the shell, the piston is arranged in the cavity and slidably connected with the shell, and the piston and the shell can jointly define a main combustion chamber; a first ammonia cracking catalyst layer is arranged on the inner wall surface of the main combustion chamber; the first nozzle is connected with the cylinder body and is configured to inject ammonia into the main combustion chamber; the spark plug is connected with the cylinder body and is constructed to ignite fuel in the main combustion chamber, the structure of the ammonia fuel internal combustion engine is simplified, and the combustion speed and the combustion stability of ammonia are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion engine structures, and in particular to an ammonia fuel internal combustion engine and a control method thereof. Background Art

[0002] As global attention to climate change increases, reducing greenhouse gas emissions has become a common goal for all walks of life. As one of the main sources of greenhouse gas emissions, the transportation industry has an especially urgent task of reducing emissions. Traditional cars are generally powered by gasoline or diesel, which produces a large amount of carbon dioxide when burned. Hydrogen, as a clean, carbon-free fuel, is being considered as an alternative fuel for internal combustion engines to reduce carbon emissions. However, there are still major limitations on the production, transportation, and storage of hydrogen. Ammonia, also as a clean, carbon-free fuel, has benefited from its early mature applications in the agricultural field. It already has a complete infrastructure in terms of production, storage, and transportation, and is more cost-effective. At the same time, the high octane number of ammonia enables it to significantly reduce the risk of knocking in internal combustion engines when used in internal combustion engines.

[0003] In the related art, internal combustion engines using ammonia as an alternative fuel have the disadvantages of complex structure, poor combustion speed and combustion stability. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an ammonia fuel internal combustion engine, which is conducive to simplifying the structure of the ammonia fuel internal combustion engine and improving the combustion speed and combustion stability of ammonia.

[0005] The invention also provides a control method.

[0006] An ammonia fuel internal combustion engine according to an embodiment of the first aspect of the present invention includes: a cylinder body, including a shell and a piston, a cavity is provided in the shell, the piston is arranged in the cavity and is slidably connected to the shell, the piston can define a main combustion chamber together with the shell, and the inner wall surface of the main combustion chamber is provided with a first ammonia cracking catalyst layer; a first nozzle, connected to the cylinder body, and is configured to inject ammonia into the main combustion chamber; a spark plug, connected to the cylinder body, and is configured to ignite the fuel in the main combustion chamber.

[0007] The ammonia fuel internal combustion engine according to the embodiment of the present invention has at least the following beneficial effects: the cylinder includes a shell and a piston, the piston is arranged in the cavity and can slide back and forth along the inner wall surface of the cavity, the piston can define a main combustion chamber together with the shell, the main combustion chamber provides a combustion space for the fuel, and the piston is driven to slide by the combustion of the fuel. The ammonia fuel internal combustion engine is provided with a first ammonia cracking catalytic layer on the inner wall surface of the main combustion chamber, that is, the main combustion chamber is also integrated with an ammonia cracking catalytic function, which is conducive to simplifying the structure of the ammonia fuel internal combustion engine compared to some internal combustion engines that use additional cracking devices to crack ammonia. And reduce the production cost of the ammonia fuel internal combustion engine. The first nozzle is constructed to inject ammonia into the main combustion chamber. Under the cracking catalytic action of the first ammonia cracking catalyst layer, part of the ammonia is cracked into hydrogen, and the cracking efficiency of ammonia is improved, so that an ammonia-hydrogen-air mixture is formed in the main combustion chamber. The spark plug is constructed to ignite the fuel in the main combustion chamber. Under the ignition action of the spark plug, the ammonia and hydrogen are mixed and burned to form a high-temperature and high-pressure environment, which is beneficial to improving the cracking efficiency of ammonia, can effectively improve the combustion speed and combustion stability of the fuel, and is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0008] According to some embodiments of the present invention, a first ammonia cracking catalytic layer is provided on the wall of the main combustion chamber opposite to the piston; and / or,

[0009] The surface of the piston connected with the main combustion chamber is provided with a first ammonia cracking catalytic layer.

[0010] Optionally, a first ammonia cracking catalytic layer is provided on the wall surface of the main combustion chamber opposite to the piston, that is, the first ammonia cracking catalytic layer is provided on the top surface of the main combustion chamber. Under the injection action of the first nozzle, ammonia is injected from top to bottom, and ammonia can be connected with the first ammonia cracking catalytic layer to improve the cracking efficiency of ammonia, so that an ammonia-hydrogen-air mixture is formed in the main combustion chamber, and the hydrogen content can be increased to effectively improve the combustion rate and combustion stability of the fuel, which is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine; Optionally, a first ammonia cracking catalytic layer is provided on the surface of the piston connecting with the main combustion chamber, that is, the first ammonia cracking catalytic layer is provided on the top surface of the piston. Under the injection action of the first nozzle, ammonia will fall to the top surface of the piston and be connected with the first ammonia cracking catalytic layer. In each stroke stage of the piston, the first ammonia cracking catalytic layer located on the top surface of the piston can further promote the cracking of ammonia, so that an ammonia-hydrogen-air mixture is formed in the main combustion chamber, and the hydrogen content can be increased to effectively improve the combustion rate and combustion stability of the fuel, which is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0011] According to some embodiments of the present invention, the shell has a pre-combustion chamber, which is connected to the end of the main combustion chamber away from the piston, the spark plug is connected to the end of the pre-combustion chamber away from the main combustion chamber, and the inner wall surface of the pre-combustion chamber is provided with a second ammonia cracking catalyst layer.

[0012] The shell has a pre-combustion chamber, which is connected to an end of the main combustion chamber away from the piston, and a second ammonia cracking catalytic layer is provided on the inner wall of the pre-combustion chamber. The spark plug is connected to the end of the pre-combustion chamber away from the main combustion chamber. Under the reciprocating motion of the piston, the gas containing ammonia in the main combustion chamber can enter the pre-combustion chamber, and under the influence of the second ammonia cracking catalytic layer, the ammonia in this part of the gas is promoted to be cracked, so that an ammonia-hydrogen-air mixture is formed in the pre-combustion chamber. Under the ignition action of the spark plug, the mixture in the pre-combustion chamber is burned with high intensity to form a pre-combustion flame. The pre-combustion flame jets from the pre-combustion chamber into the main combustion chamber. Compared with the method of directly igniting the main combustion chamber by the spark plug, it is beneficial to produce a stronger ignition effect on the mixture in the main combustion chamber, which can increase the combustion speed and combustion stability of the fuel, and is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0013] According to some embodiments of the present invention, the ammonia fuel internal combustion engine further includes a second nozzle connected to the cylinder body and configured to inject ammonia into the pre-combustion chamber.

[0014] After the precombustion flame is formed in the precombustion chamber, the second nozzle can realize the secondary injection of ammonia, so that the ammonia is injected into the precombustion flame. Under the action of the high-temperature flame, the ammonia injected from the second nozzle can be cracked into hydrogen. This part of the pyrolyzed hydrogen can have a combustion-supporting effect on the precombustion flame, and at the same time, the total amount of fuel and flame energy in the precombustion chamber are increased, and the jet intensity of the precombustion flame is improved, which is beneficial to produce a stronger ignition effect on the mixture in the main combustion chamber, and can increase the combustion speed and combustion stability of the fuel, which is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0015] According to some embodiments of the present invention, the shell further has a pre-cracking chamber, an extended flow channel is provided in the pre-cracking chamber, a third ammonia cracking catalytic layer is provided on the inner wall surface of the extended flow channel, the second nozzle is connected to one end of the extended flow channel, and the other end of the extended flow channel is connected to the pre-combustion chamber.

[0016] Specifically, the shell also includes a pre-cracking chamber, an extended flow channel is provided in the pre-cracking chamber, a third ammonia cracking catalytic layer is provided on the inner wall surface of the extended flow channel, a second nozzle is connected to one end of the extended flow channel, ammonia ejected from the second nozzle enters the extended flow channel, and under the cracking catalytic action of the third ammonia cracking catalytic layer, the cracking efficiency of ammonia is improved to increase the content of hydrogen, and the mixed gas of ammonia and hydrogen enters the pre-combustion chamber after passing through the extended flow channel, which can improve the intensity of the pre-combustion flame, so that after the pre-combustion flame jets to the main combustion chamber, it is beneficial to produce a stronger ignition effect on the mixed gas in the main combustion chamber, which can improve the combustion speed and combustion stability of the fuel, and is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0017] According to some embodiments of the present invention, a spiral blade is provided in the pre-cracking chamber, which is connected to the inner wall surface of the pre-cracking chamber and jointly defines an extended flow channel, the extended flow channel is spiral, and a third ammonia cracking catalyst layer is provided on the surface of the spiral blade.

[0018] Specifically, a spiral sheet is provided in the pre-cracking chamber, and the spiral sheet is connected to the inner wall surface of the pre-cracking chamber to jointly define a spiral extended flow channel, which is beneficial to increasing the path of the extended flow channel, so that the ammonia gas ejected from the second nozzle flows in a spiral shape and fully contacts with the third ammonia cracking catalytic layer on the surface of the spiral sheet, so as to improve the cracking efficiency of ammonia and increase the content of hydrogen. The pre-cracking chamber is connected to the pre-combustion chamber, and the mixture of ammonia and hydrogen is conducted into the pre-combustion chamber, which can improve the intensity of the pre-combustion flame, so that after the pre-combustion flame jets to the main combustion chamber, it is beneficial to produce a stronger ignition effect on the mixture in the main combustion chamber, which can improve the combustion speed and combustion stability of the fuel, and is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0019] According to some embodiments of the present invention, the shell further includes a pre-cracking chamber and a plasma generator, the plasma generator is disposed in the pre-cracking chamber, the second nozzle is connected to one end of the pre-cracking chamber, and the other end of the pre-cracking chamber is connected to the pre-combustion chamber.

[0020] Optionally, the shell also includes a pre-cracking chamber and a plasma generator, the plasma generator is arranged in the pre-cracking chamber, the second nozzle is connected to one end of the pre-cracking chamber, the second nozzle can inject ammonia into the pre-cracking chamber, and through the operation of the plasma generator, it can catalyze the cracking of ammonia and improve the cracking efficiency of ammonia to increase the content of hydrogen. The pre-cracking chamber is connected to the pre-combustion chamber, and the mixed gas of ammonia and hydrogen is conducted into the pre-combustion chamber. By controlling the operating power of the plasma generator, the content of hydrogen cracked from ammonia is controlled to meet the needs of different operating conditions.

[0021] According to some embodiments of the present invention, the ammonia fuel internal combustion engine also includes a control valve, which is connected to the junction of the pre-cracking chamber and the pre-combustion chamber, and the control valve is constructed to connect the pre-cracking chamber and the pre-combustion chamber when the pressure of the pre-cracking chamber is greater than the pressure of the pre-combustion chamber.

[0022] Specifically, the ammonia fuel internal combustion engine also includes a control valve, which is connected to the junction of the pre-cracking chamber and the pre-combustion chamber, and the control valve is constructed to connect the pre-cracking chamber and the pre-combustion chamber when the pressure in the pre-cracking chamber is greater than the pressure in the pre-combustion chamber, that is, when the second nozzle injects ammonia into the pre-cracking chamber, the pressure in the pre-cracking chamber can be greater than the pressure in the pre-combustion chamber, so that the mixed gas in the pre-cracking chamber can pass into the pre-combustion chamber, and under the ignition action of the spark plug, the fuel in the pre-combustion chamber is ignited, and the pre-combustion chamber forms a high temperature and high pressure environment. At this time, the pressure in the pre-combustion chamber is greater than the pressure in the pre-cracking chamber, and the control valve can block the connection between the pre-combustion chamber and the pre-cracking chamber, thereby preventing the flame from propagating into the pre-cracking chamber.

[0023] The control method according to the second aspect of the present invention is applied to the ammonia fuel internal combustion engine of any one of the first aspects; the control method comprises:

[0024] The control piston and the housing together define a main combustion chamber;

[0025] controlling the first nozzle to inject ammonia into the main combustion chamber;

[0026] The spark plug is controlled to ignite the fuel in the main combustion chamber.

[0027] The control method according to the embodiment of the present invention has at least the following beneficial effects: the cylinder includes a shell and a piston, the piston is arranged in the cavity and can slide back and forth along the inner wall surface of the cavity, the control method controls the piston and the shell to jointly define a main combustion chamber, the main combustion chamber provides a combustion space for the fuel, the ammonia fuel internal combustion engine is provided with a first ammonia cracking catalytic layer on the inner wall surface of the main combustion chamber, that is, the main combustion chamber is also integrated with an ammonia cracking catalytic function, compared with some internal combustion engines that use additional cracking devices to crack ammonia, it is conducive to simplifying the structure of the ammonia fuel internal combustion engine and reducing the ammonia fuel internal combustion engine. The control method controls the first nozzle to inject ammonia into the main combustion chamber, and under the cracking catalytic action of the first ammonia cracking catalyst layer, part of the ammonia is cracked into hydrogen, and the cracking efficiency of ammonia is improved, so that an ammonia-hydrogen-air mixture is formed in the main combustion chamber. The control method controls the spark plug to ignite the fuel in the main combustion chamber. Under the ignition action of the spark plug, ammonia and hydrogen are mixed and burned to form a high-temperature and high-pressure environment, which is beneficial to improving the cracking efficiency of ammonia, and can effectively improve the combustion speed and combustion stability of the fuel, which is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0028] According to some embodiments of the present invention, the housing has a pre-combustion chamber, the pre-combustion chamber is connected to the end of the main combustion chamber away from the piston, the spark plug is connected to the end of the pre-combustion chamber away from the main combustion chamber, and the inner wall surface of the pre-combustion chamber is provided with a second ammonia cracking catalytic layer; the ammonia fuel internal combustion engine also includes a second nozzle, the second nozzle is connected to the cylinder body, and is configured to inject ammonia into the pre-combustion chamber;

[0029] Controlling the spark plug to ignite the fuel in the main combustion chamber includes:

[0030] Controlling the spark plug to ignite the fuel in the pre-combustion chamber to form a pre-combustion flame;

[0031] The second nozzle is controlled to inject ammonia into the pre-combustion flame, thereby increasing the jet intensity of the pre-combustion flame and causing the pre-combustion flame to jet into the main combustion chamber.

[0032] The housing has a pre-combustion chamber, which is connected to an end of the main combustion chamber away from the piston, and the inner wall of the pre-combustion chamber is provided with a second ammonia cracking catalytic layer. The spark plug is connected to the end of the pre-combustion chamber away from the main combustion chamber. Under the reciprocating motion of the piston, the gas containing ammonia in the main combustion chamber can enter the pre-combustion chamber, and under the influence of the second ammonia cracking catalytic layer, the ammonia in this part of the gas is cracked, so that an ammonia-hydrogen-air mixture is formed in the pre-combustion chamber. The control method controls the spark plug to ignite, so that the mixture in the pre-combustion chamber burns with high intensity to form a pre-combustion flame. The control method can control the second nozzle to inject ammonia into the pre-combustion flame, so that the ammonia injected by the second nozzle can be cracked into hydrogen under the action of the high-temperature flame. This part of the pyrolyzed hydrogen can produce a combustion-supporting effect on the pre-combustion flame, and at the same time increase the total amount of fuel and flame energy in the pre-combustion chamber, improve the jet intensity of the pre-combustion flame, which is conducive to producing a stronger ignition effect on the mixture in the main combustion chamber, can improve the combustion speed and combustion stability of the fuel, and is conducive to improving the combustion performance of the ammonia fuel internal combustion engine.

[0033] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0035] Figure 1 A schematic structural diagram of a combustion chamber of the prior art according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic structural diagram of an ammonia fuel internal combustion engine according to a first embodiment of the present invention;

[0037] Figure 3 A schematic structural diagram of an ammonia fuel internal combustion engine according to a second embodiment of the present invention, in which a pre-combustion chamber and a second nozzle are added;

[0038] Figure 4 A schematic structural diagram of an ammonia fuel internal combustion engine according to a third embodiment of the present invention with a pre-cracking chamber added;

[0039] Figure 5 A schematic diagram of the structure of an ammonia fuel internal combustion engine according to a fourth embodiment of the present invention in which a pre-cracking chamber and a plasma generator are added;

[0040] Figure 6 A flow chart of a control method according to an embodiment of the present invention;

[0041] Figure 7 This is a flow chart of a two-stage ammonia injection in a pre-combustion chamber according to a control method according to an embodiment of the present invention.

[0042] Figure Number:

[0043] 100, cylinder body; 110, housing; 120, piston; 130, main combustion chamber; 140, first ammonia cracking catalyst layer;

[0044] 210, first nozzle; 220, second nozzle;

[0045] 300, spark plug;

[0046] 400, pre-combustion chamber; 410, second ammonia cracking catalyst layer;

[0047] 500, pre-cracking chamber; 510, extended flow channel;

[0048] 600. Plasma generator. DETAILED DESCRIPTION

[0049] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0050] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0051] In the description of the present invention, "a plurality" means more than two. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0052] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0053] In the related art, although ammonia has many advantages as an alternative fuel for internal combustion engines, there are still some problems in the practical application of ammonia. For example, ammonia has a narrow flammability range, a low laminar flame speed, and unstable combustion. To this end, the ammonia fuel internal combustion engine provided in the embodiment of the present invention is conducive to simplifying the structure of the ammonia fuel internal combustion engine and improving the combustion speed and combustion stability of ammonia.

[0054] Reference Figure 1 to Figure 2As shown, the ammonia fuel internal combustion engine provided by the first embodiment of the present invention includes: a cylinder block 100, a first nozzle 210 and a spark plug 300.

[0055] Among them, the cylinder body 100 includes a shell 110 and a piston 120. The shell 110 is provided with a cavity. The piston 120 is arranged in the cavity and is slidably connected to the shell 110. During the sliding of the piston 120, the piston 120 can jointly define a main combustion chamber 130 with the shell 110. The main combustion chamber 130 provides a combustion space for the fuel, and the piston 120 is driven to slide by the combustion of the fuel. The ammonia fuel internal combustion engine is provided with a first ammonia cracking catalyst layer 140 on the inner wall surface of the main combustion chamber 130, that is, the main combustion chamber 130 is also integrated with an ammonia cracking catalytic function.

[0056] The first nozzle 210 is configured to inject ammonia into the main combustion chamber 130. Under the cracking catalytic action of the first ammonia cracking catalyst layer 140, part of the ammonia is cracked into hydrogen, and the cracking efficiency of ammonia is improved, so that an ammonia-hydrogen-air mixture is formed in the main combustion chamber 130. The spark plug 300 is configured to ignite the fuel in the main combustion chamber 130. Under the ignition action of the spark plug 300, ammonia and hydrogen are mixed and burned to form a high-temperature and high-pressure environment, which is beneficial to improving the cracking efficiency of ammonia, and can effectively improve the combustion speed and combustion stability of the fuel, which is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0057] Reference Figure 1 , Figure 1 The structure diagram of the combustion chamber of the prior art is shown in FIG. 1 ; the cylinder 100 includes a housing 110 and a piston 120, the piston 120 is slidably connected to the housing 110, and the piston 120 and the housing 110 can define a main combustion chamber 130 together, and the fuel is mainly burned in the main combustion chamber 130 to drive the piston 120 to reciprocate. In the related art, the internal combustion engine using ammonia as fuel generally needs to be additionally provided with a cracking device to realize the cracking of ammonia, which has the defects of complex structure, large volume and high production cost.

[0058] The ammonia fuel internal combustion engine provided by the embodiment of the present invention has a first ammonia cracking catalytic layer 140 disposed on the inner wall surface of the main combustion chamber 130, so that the ammonia fuel internal combustion engine has the ability to catalyze ammonia cracking. By adding hydrogen into the ammonia fuel internal combustion engine, the performance of the ammonia fuel internal combustion engine is improved, the complexity of the internal combustion engine system is reduced, and the manufacturing cost is reduced. The ammonia fuel internal combustion engine can effectively improve the cracking effect of ammonia through the catalytic effect of the first ammonia cracking catalytic layer 140 and the high temperature and high pressure environment formed by combustion, so as to improve the combustion speed and combustion stability of the fuel.

[0059] Reference Figure 1 and Figure 2As shown, it can be understood that, taking the example that the main combustion chamber 130 is located above the piston 120, the main combustion chamber 130 is provided with a first ammonia cracking catalyst layer 140 on the wall opposite to the piston 120, that is, the top surface of the main combustion chamber 130 is provided with the first ammonia cracking catalyst layer 140.

[0060] Under the injection action of the first nozzle 210, ammonia is injected from top to bottom, and the ammonia can connect with the first ammonia cracking catalyst layer 140 to improve the cracking efficiency of ammonia, so that an ammonia-hydrogen-air mixture is formed in the main combustion chamber 130, which can increase the hydrogen content to effectively improve the combustion speed and combustion stability of the fuel, which is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0061] Reference Figure 1 and Figure 2 As shown, it can be understood that the surface where the piston 120 and the main combustion chamber 130 meet is also provided with a first ammonia cracking catalytic layer 140, that is, the top surface of the piston 120 and the wall surface of the main combustion chamber 130 opposite to the piston 120 are respectively provided with two first ammonia cracking catalytic layers 140. Under the spraying action of the first nozzle 210, ammonia will fall to the top surface of the piston 120 and contact with the first ammonia cracking catalytic layer 140. In each stroke stage of the piston 120, the first ammonia cracking catalytic layer 140 located on the top surface of the piston 120 can further promote ammonia cracking, so that a mixed gas of ammonia-hydrogen-air is formed in the main combustion chamber 130, which can increase the content of hydrogen, so as to effectively improve the combustion speed and combustion stability of the fuel, which is conducive to improving the combustion performance of the ammonia fuel internal combustion engine.

[0062] Specifically, the upper end surface of the piston 120 has a concave pit surface, and the setting of the pit surface can ensure that the sliding of the piston 120 does not cause collision with the first nozzle 210, the spark plug 300 and other components, and ensure that the first nozzle 210 can inject ammonia into the main combustion chamber 130. The upper end surface and the pit surface of the piston 120 are both provided with a first ammonia cracking catalyst layer 140.

[0063] It should be noted that the ammonia fuel internal combustion engine can form the first ammonia cracking catalytic layer 140 on the inner wall surface of the main combustion chamber 130 by plating, coating, compounding, etc.

[0064] It should be understood that, in some other embodiments, the ammonia fuel internal combustion engine is provided with the first ammonia cracking catalyst layer 140 only on the wall surface opposite to the main combustion chamber 130 and the piston 120, or the first ammonia cracking catalyst layer 140 is provided only on the end surface where the piston 120 and the main combustion chamber 130 meet, so that the ammonia fuel internal combustion engine has the ability of ammonia cracking catalysis, and the performance of the ammonia fuel internal combustion engine is improved by adding hydrogen into the ammonia fuel internal combustion engine.

[0065] It should be understood that in some other embodiments, the ammonia fuel internal combustion engine is provided with a first ammonia cracking catalyst layer 140 on the side wall surface of the main combustion chamber 130, so that the ammonia fuel internal combustion engine has the ability of ammonia cracking catalysis, and the performance of the ammonia fuel internal combustion engine is improved by adding hydrogen into the ammonia fuel internal combustion engine.

[0066] Reference Figure 3 As shown, the ammonia fuel internal combustion engine provided by the second embodiment of the present invention is additionally provided with a pre-combustion chamber 400 and a second nozzle 220 on the basis of the first embodiment, and the spark plug 300 is arranged at one end of the pre-combustion chamber 400 away from the main combustion chamber 130.

[0067] Reference Figure 3 As shown, specifically, the housing 110 has a pre-combustion chamber 400, which is connected to one end of the main combustion chamber 130 away from the piston 120. Specifically, a bottom hole is provided at the lower end of the pre-combustion chamber 400, and the pre-combustion chamber 400 is connected to the main combustion chamber 130 through the bottom hole. The spark plug 300 is connected to one end of the pre-combustion chamber 400 away from the main combustion chamber 130, and the inner wall surface of the pre-combustion chamber 400 is provided with a second ammonia cracking catalytic layer 410. Specifically, the second ammonia cracking catalytic layer 410 is provided on the top surface, bottom surface or side surface of the pre-combustion chamber 400.

[0068] Reference Figure 3 As shown, under the reciprocating motion of the piston 120, the gas containing ammonia in the main combustion chamber 130 can pass through the bottom hole and enter the pre-combustion chamber 400, and is affected by the second ammonia cracking catalyst layer 410 to promote the cracking of ammonia in this part of the gas, so that an ammonia-hydrogen-air mixture is formed in the pre-combustion chamber 400. Under the ignition action of the spark plug 300, the mixture in the pre-combustion chamber 400 is burned with high intensity to form a pre-combustion flame, and the pre-combustion flame jets from the pre-combustion chamber 400 to the main combustion chamber 130. Compared with the method in which the spark plug 300 directly ignites the main combustion chamber 130, it is beneficial to produce a stronger ignition effect on the mixture in the main combustion chamber 130, which can increase the combustion speed and combustion stability of the fuel, and is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0069] Reference Figure 3As shown, it can be understood that the ammonia fuel internal combustion engine also includes a second nozzle 220, which is connected to the cylinder body 100 and is configured to inject ammonia into the pre-combustion chamber 400. After the pre-combustion flame is formed in the pre-combustion chamber 400, the second nozzle 220 can realize the secondary injection of ammonia, so that the ammonia is injected into the pre-combustion flame. Under the action of the high-temperature flame, the ammonia injected by the second nozzle 220 can be cracked into hydrogen. This partially pyrolyzed hydrogen can produce a combustion-supporting effect on the pre-combustion flame, while increasing the total amount of fuel and flame energy in the pre-combustion chamber 400, and improving the jet intensity of the pre-combustion flame, which is conducive to producing a stronger ignition effect on the mixed gas in the main combustion chamber 130, and can increase the combustion speed and combustion stability of the fuel, which is conducive to improving the combustion performance of the ammonia fuel internal combustion engine.

[0070] Reference Figure 4 As shown, the ammonia fuel internal combustion engine provided by the third embodiment of the present invention is additionally provided with a pre-cracking chamber 500 on the basis of the second embodiment, and both ends of the pre-cracking chamber 500 are respectively connected to the second nozzle 220 and the pre-combustion chamber 400, so that the ammonia gas ejected from the second nozzle 220 is pre-cracking to increase the hydrogen content, thereby improving the combustion speed and combustion stability of the ammonia fuel internal combustion engine.

[0071] Specifically, the shell 110 further has a pre-cracking chamber 500, in which an extended flow channel 510 is provided, and an inner wall surface of the extended flow channel 510 is provided with a third ammonia cracking catalyst layer, the second nozzle 220 is connected to one end of the extended flow channel 510, and the other end of the extended flow channel 510 is connected to the pre-combustion chamber 400.

[0072] The ammonia ejected from the second nozzle 220 is passed into the extended flow channel 510. Under the cracking catalytic action of the third ammonia cracking catalyst layer, the cracking efficiency of ammonia is improved to increase the content of hydrogen. After the mixed gas of ammonia and hydrogen flows through the extended flow channel 510, it enters the pre-combustion chamber 400, which can increase the intensity of the pre-combustion flame. After the pre-combustion flame jets to the main combustion chamber 130, it is beneficial to produce a stronger ignition effect on the mixed gas in the main combustion chamber 130, which can increase the combustion speed and combustion stability of the fuel, and is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0073] It is understandable that, specifically, a spiral sheet is provided in the pre-cracking chamber 500, and the spiral sheet is connected to the inner wall surface of the pre-cracking chamber 500 to jointly define a spiral extension flow channel 510, which is conducive to increasing the path of the extension flow channel 510, so that the ammonia gas ejected from the second nozzle 220 flows downward in a spiral shape and fully contacts the third ammonia cracking catalytic layer on the surface of the spiral sheet to improve the cracking efficiency of ammonia and increase the content of hydrogen. The pre-cracking chamber 500 is connected to the pre-combustion chamber 400, and the mixture of ammonia and hydrogen is conducted to the pre-combustion flame of the pre-combustion chamber 400, which can improve the intensity of the pre-combustion flame, so that after the pre-combustion flame jets to the main combustion chamber 130, it is conducive to producing a stronger ignition effect on the mixture in the main combustion chamber 130, which can improve the combustion speed and combustion stability of the fuel, and is conducive to improving the combustion performance of the ammonia fuel internal combustion engine.

[0074] Specifically, the third ammonia cracking catalytic layer is provided on the upper and lower surfaces of the spiral blades, which is beneficial to increasing the area of ​​the third ammonia cracking catalytic layer on the spiral blades and achieving sufficient contact between ammonia and the third ammonia cracking catalytic layer to improve the cracking efficiency of ammonia. The mixture of ammonia and hydrogen is conducted into the pre-combustion chamber 400, which can increase the hydrogen content in the pre-combustion chamber 400 and increase the formation intensity of the pre-combustion flame.

[0075] It can be understood that, specifically, the ammonia fuel internal combustion engine further includes a control valve, which is connected to the junction of the pre-cracking chamber 500 and the pre-combustion chamber 400, and the control valve is constructed to connect the pre-cracking chamber 500 and the pre-combustion chamber 400 when the pressure of the pre-cracking chamber 500 is greater than the pressure of the pre-combustion chamber 400, that is, when the second nozzle 220 injects ammonia into the pre-cracking chamber 500, the pressure in the pre-cracking chamber 500 can be greater than the pressure in the pre-combustion chamber 400, so that the mixed gas in the pre-cracking chamber 500 can pass into the pre-combustion chamber 400, and under the ignition action of the spark plug 300, the fuel in the pre-combustion chamber 400 is ignited, and the pre-combustion chamber 400 forms a high temperature and high pressure environment. At this time, the pressure of the pre-combustion chamber 400 is greater than the pressure of the pre-cracking chamber 500, and the control valve can block the connection between the pre-combustion chamber 400 and the pre-cracking chamber 500, thereby preventing the flame from propagating into the pre-cracking chamber 500.

[0076] Specifically, the control valve can be a mechanical inward-pushing spring valve. When combustion occurs in the pre-combustion chamber 400, the pressure will increase. The increased pressure will push the spring valve into the pre-cracking chamber 500, disconnecting the communication path between the pre-cracking chamber 500 and the pre-combustion chamber 400, and preventing the flame from spreading into the pre-cracking chamber 500.

[0077] It should be noted that the first ammonia cracking catalytic layer 140, the second ammonia cracking catalytic layer 410 and the third ammonia cracking catalytic layer can be one or more of a single metal catalyst, a bimetallic catalyst, a carbide catalyst and a nitride catalyst. The catalysts mentioned belong to conventional technical means in the art and will not be described in detail here.

[0078] It should be understood that in some other embodiments, the extended flow channel 510 is in a curved, folded line, serpentine, etc. shape, which is beneficial to increase the path of the extended flow channel 510 so that the ammonia gas ejected from the second nozzle 220 can fully contact the third ammonia cracking catalyst layer to improve the cracking efficiency of ammonia and increase the hydrogen content.

[0079] Reference Figure 5 As shown, the ammonia fuel internal combustion engine provided by the fourth embodiment of the present invention is additionally provided with a pre-cracking chamber 500 and a plasma generator 600 on the basis of the third embodiment, and the two ends of the pre-cracking chamber 500 are respectively connected to the second nozzle 220 and the pre-combustion chamber 400, so that the plasma generator 600 pre-cracking the ammonia to increase the hydrogen content, improve the combustion speed and combustion stability.

[0080] Specifically, the shell 110 further includes a pre-cracking chamber 500 and a plasma generator 600 . The plasma generator 600 is disposed in the pre-cracking chamber 500 . The second nozzle 220 is connected to one end of the pre-cracking chamber 500 , and the other end of the pre-cracking chamber 500 is connected to the pre-combustion chamber 400 .

[0081] The plasma generator 600 is arranged in the pre-cracking chamber 500, and the second nozzle 220 is connected to one end of the pre-cracking chamber 500. The second nozzle 220 can inject ammonia into the pre-cracking chamber 500. Through the operation of the plasma generator 600, it can catalyze the cracking of ammonia and improve the cracking efficiency of ammonia to increase the content of hydrogen. The pre-cracking chamber 500 is connected to the pre-combustion chamber 400, and the mixed gas of ammonia and hydrogen is conducted to the pre-combustion flame of the pre-combustion chamber 400, which is beneficial to the combustion of the pre-combustion flame. By controlling the operating power of the plasma generator 600, the content of hydrogen cracked from ammonia can be controlled to meet the needs of different operating conditions.

[0082] It should be noted that the plasma generator 600 can generate high-energy electrons, which collide with surrounding gas molecules (such as ammonia molecules) under the action of the electric field, thereby exciting, dissociating and ionizing these molecules to form reactive species in a high-energy activated state. When high-energy electrons collide inelastically with ammonia molecules (NH3), energy is transferred. These high-energy electrons transfer energy to ammonia molecules, breaking their internal chemical bonds (such as NH bonds), causing ammonia molecules to dissociate into nitrogen atoms (N), hydrogen atoms (H) or combinations thereof (such as NH, NH2, etc.).

[0083] It can be understood that, specifically, the ammonia fuel internal combustion engine further includes a control valve, which is connected to the junction of the pre-cracking chamber 500 and the pre-combustion chamber 400, and the control valve is constructed to connect the pre-cracking chamber 500 and the pre-combustion chamber 400 when the pressure of the pre-cracking chamber 500 is greater than the pressure of the pre-combustion chamber 400, that is, when the second nozzle 220 injects ammonia into the pre-cracking chamber 500, the pressure in the pre-cracking chamber 500 can be greater than the pressure in the pre-combustion chamber 400, so that the mixed gas in the pre-cracking chamber 500 can pass into the pre-combustion chamber 400, and under the ignition action of the spark plug 300, the fuel in the pre-combustion chamber 400 is ignited, and the pre-combustion chamber 400 forms a high temperature and high pressure environment. At this time, the pressure of the pre-combustion chamber 400 is greater than the pressure of the pre-cracking chamber 500, and the control valve can block the connection between the pre-combustion chamber 400 and the pre-cracking chamber 500, thereby preventing the flame from propagating into the pre-cracking chamber 500.

[0084] Specifically, the control valve can be a mechanical inward-pushing spring valve. When combustion occurs in the pre-combustion chamber 400, the pressure will increase. The increased pressure will push the spring valve into the pre-cracking chamber 500, disconnecting the communication path between the pre-cracking chamber 500 and the pre-combustion chamber 400, and preventing the flame from spreading into the pre-cracking chamber 500.

[0085] Reference Figure 2 , Figure 3 and Figure 6 As shown, a control method provided by an embodiment of the present invention is applied to an ammonia fuel internal combustion engine as shown in any of the above embodiments. The control method includes:

[0086] Step S100, the control piston 120 and the housing 110 jointly define a main combustion chamber 130;

[0087] Step S200, controlling the first nozzle 210 to inject ammonia into the main combustion chamber 130;

[0088] In step S300 , the spark plug 300 is controlled to ignite the fuel in the main combustion chamber 130 .

[0089] Reference Figure 2 , Figure 3 and Figure 6As shown, the cylinder 100 includes a housing 110 and a piston 120. The piston 120 is disposed in the cavity and can slide back and forth along the inner wall surface of the cavity. The control method controls the piston 120 and the housing 110 to jointly define a main combustion chamber 130. The main combustion chamber 130 provides a combustion space for the fuel, and the piston 120 is driven to slide by the combustion of the fuel. The ammonia fuel internal combustion engine is provided with a first ammonia cracking catalytic layer 140 on the inner wall surface of the main combustion chamber 130, that is, the main combustion chamber 130 is also integrated with an ammonia cracking catalytic function. Compared with some internal combustion engines that use additional cracking devices to crack ammonia, the ammonia fuel internal combustion engine is conducive to simplifying the structure of the ammonia fuel internal combustion engine and reducing the ammonia fuel. The manufacturing cost of the fuel internal combustion engine is reduced. The control method controls the first nozzle 210 to inject ammonia into the main combustion chamber 130. Under the cracking catalytic action of the first ammonia cracking catalyst layer 140, part of the ammonia is cracked into hydrogen, and the cracking efficiency of ammonia is improved, so that an ammonia-hydrogen-air mixture is formed in the main combustion chamber 130. The control method controls the spark plug 300 to ignite the fuel in the main combustion chamber 130. Under the ignition action of the spark plug 300, ammonia and hydrogen are mixed and burned to form a high-temperature and high-pressure environment, which is beneficial to improving the cracking efficiency of ammonia, and can effectively improve the combustion speed and combustion stability of the fuel, which is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0090] Reference Figure 2 , Figure 3 and Figure 6 As shown, it can be understood that the housing 110 has a pre-combustion chamber 400, which is communicated with one end of the main combustion chamber 130 away from the piston 120, and the spark plug 300 is connected to the end of the pre-combustion chamber 400 away from the main combustion chamber 130, and the inner wall surface of the pre-combustion chamber 400 is provided with a second ammonia cracking catalytic layer 410; the ammonia fuel internal combustion engine also includes a second nozzle 220, which is connected to the cylinder body 100 and is configured to inject ammonia into the pre-combustion chamber 400;

[0091] Reference Figure 3 and Figure 7 As shown, in step S300, the control method controls the spark plug 300 to ignite the fuel in the main combustion chamber 130, including the following steps:

[0092] Step S310, controlling the spark plug 300 to ignite the fuel in the pre-combustion chamber 400 to form a pre-combustion flame;

[0093] Step S320 , controlling the second nozzle 220 to inject ammonia into the pre-combustion flame, thereby increasing the jet intensity of the pre-combustion flame and causing the pre-combustion flame to jet into the main combustion chamber 130 .

[0094] Reference Figure 3 and Figure 7As shown, in step S310, the housing 110 has a pre-combustion chamber 400, which is connected to one end of the main combustion chamber 130 away from the piston 120, and the inner wall surface of the pre-combustion chamber 400 is provided with a second ammonia cracking catalytic layer 410, and the spark plug 300 is connected to the end of the pre-combustion chamber 400 away from the main combustion chamber 130. Under the reciprocating motion of the piston 120, the gas containing ammonia in the main combustion chamber 130 can enter the pre-combustion chamber 400, and is affected by the second ammonia cracking catalytic layer 410 to promote the cracking of ammonia in this part of the gas, so that an ammonia-hydrogen-air mixture is formed in the pre-combustion chamber 400. The control method controls the spark plug 300 to ignite, so that the mixture in the pre-combustion chamber 400 undergoes high-intensity combustion to form a pre-combustion flame.

[0095] Reference Figure 3 and Figure 7 As shown, in step S320, the control method can control the second nozzle 220 to inject ammonia into the pre-combustion flame, so that the ammonia injected by the second nozzle 220 can be cracked into hydrogen under the action of the high-temperature flame. This part of the pyrolyzed hydrogen can have a combustion-supporting effect on the pre-combustion flame, while increasing the total amount of fuel and flame energy in the pre-combustion chamber 400, improving the jet intensity of the pre-combustion flame, and being beneficial to producing a stronger ignition effect on the mixture in the main combustion chamber 130, which can increase the combustion speed and combustion stability of the fuel, and is beneficial to improving the combustion performance of the ammonia fuel internal combustion engine.

[0096] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. An ammonia fuel internal combustion engine, characterized in that: include: A cylinder (100) comprises a shell (110) and a piston (120), wherein a cavity is provided in the shell (110), the piston (120) is arranged in the cavity and is slidably connected to the shell (110), the piston (120) and the shell (110) can define a main combustion chamber (130) together, and a first ammonia cracking catalytic layer (140) is provided on an inner wall surface of the main combustion chamber (130); a first nozzle (210), connected to the cylinder (100) and configured to inject ammonia into the main combustion chamber (130); A spark plug (300) is connected to the cylinder body (100) and is configured to ignite the fuel in the main combustion chamber (130).

2. The ammonia fuel internal combustion engine according to claim 1, characterized in that: The main combustion chamber (130) is provided with the first ammonia cracking catalytic layer (140) on a wall surface opposite to the piston (120); and / or, The first ammonia cracking catalytic layer (140) is provided on the surface of the piston (120) that is in contact with the main combustion chamber (130).

3. The ammonia fuel internal combustion engine according to claim 1, characterized in that: The housing (110) comprises a pre-combustion chamber (400), the pre-combustion chamber (400) being in communication with an end of the main combustion chamber (130) away from the piston (120), the spark plug (300) being connected to an end of the pre-combustion chamber (400) away from the main combustion chamber (130), and a second ammonia cracking catalytic layer (410) being provided on an inner wall surface of the pre-combustion chamber (400).

4. The ammonia fuel internal combustion engine according to claim 3, characterized in that: The ammonia fuel internal combustion engine further includes a second nozzle (220), which is connected to the cylinder block (100) and is configured to inject ammonia into the pre-combustion chamber (400).

5. The ammonia fuel internal combustion engine according to claim 4, characterized in that: The shell (110) further comprises a pre-cracking chamber (500), an extended flow channel (510) is provided in the pre-cracking chamber (500), a third ammonia cracking catalytic layer is provided on the inner wall surface of the extended flow channel (510), the second nozzle (220) is connected to one end of the extended flow channel (510), and the other end of the extended flow channel (510) is connected to the pre-combustion chamber (400).

6. The ammonia fuel internal combustion engine according to claim 5, characterized in that: A spiral sheet is provided in the pre-cracking chamber (500), the spiral sheet is connected to the inner wall surface of the pre-cracking chamber (500) and together defines the extended flow channel (510), the extended flow channel (510) is spiral, and the surface of the spiral sheet is provided with the third ammonia cracking catalytic layer.

7. The ammonia fuel internal combustion engine according to claim 4, characterized in that: The housing (110) further comprises a pre-cracking chamber (500) and a plasma generator (600), wherein the plasma generator (600) is disposed in the pre-cracking chamber (500), the second nozzle (220) is connected to one end of the pre-cracking chamber (500), and the other end of the pre-cracking chamber (500) is connected to the pre-combustion chamber (400).

8. The ammonia fuel internal combustion engine according to any one of claims 5 to 7, characterized in that: The ammonia fuel internal combustion engine further comprises a control valve, which is connected to the junction of the pre-cracking chamber (500) and the pre-combustion chamber (400), and the control valve is configured to connect the pre-cracking chamber (500) and the pre-combustion chamber (400) when the pressure of the pre-cracking chamber (500) is greater than the pressure of the pre-combustion chamber (400).

9. A control method, characterized in that: Applicable to an ammonia fuel internal combustion engine as claimed in any one of claims 1 to 8; The control method comprises: Controlling the piston (120) and the housing (110) to jointly define the main combustion chamber (130); controlling the first nozzle (210) to inject ammonia into the main combustion chamber (130); The spark plug (300) is controlled to ignite the fuel in the main combustion chamber (130).

10. The control method according to claim 9, characterized in that: The housing (110) comprises a pre-combustion chamber (400), the pre-combustion chamber (400) being in communication with an end of the main combustion chamber (130) away from the piston (120), the spark plug (300) being connected to an end of the pre-combustion chamber (400) away from the main combustion chamber (130), and a second ammonia cracking catalytic layer (410) being provided on an inner wall surface of the pre-combustion chamber (400); the ammonia fuel internal combustion engine further comprises a second nozzle (220), the second nozzle (220) being connected to the cylinder block (100) and being configured to inject ammonia into the pre-combustion chamber (400); The controlling the spark plug (300) to ignite the fuel in the main combustion chamber (130) comprises: controlling the spark plug (300) to ignite the fuel in the pre-combustion chamber (400) to form a pre-combustion flame; The second nozzle (220) is controlled to inject ammonia into the pre-combustion flame, thereby increasing the jet intensity of the pre-combustion flame and causing the flame of the pre-combustion chamber (400) to jet into the main combustion chamber (130).

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