Combustion organization method and internal combustion engine for implementing the combustion organization method

Abstract

The present disclosure provides a combustion organization method and an internal combustion engine for implementing the combustion organization method, wherein the combustion organization method comprises: in an intake stage of a first intake-exhaust cycle period of the internal combustion engine, introducing a first mixture into a combustion chamber, wherein the first mixture comprises fuel and air; in a negative valve overlap stage of the first intake-exhaust cycle period of the internal combustion engine, injecting ammonia into the combustion chamber, so that the ammonia generates hydrogen after a thermal cracking reaction in a high-temperature and high-pressure environment caused by combustion and high-temperature exhaust gas, wherein the negative valve overlap stage is a period when both the intake valve and the exhaust valve are closed; in an intake stage of a second intake-exhaust cycle period of the internal combustion engine, introducing a second mixture into the combustion chamber, so that the second mixture and the hydrogen perform a reforming combustion in the combustion chamber, wherein the second mixture comprises fuel and air.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of internal combustion engines, and particularly relates to a combustion organization method and an internal combustion engine for implementing the combustion organization method. BACKGROUND

[0002] With the advent of the low-carbon energy era, internal combustion engines are facing more severe challenges in improving efficiency and reducing emissions. The use of low-carbon and zero-carbon fuels in internal combustion engines has become the future development direction. Ammonia is widely concerned internationally because it does not contain carbon atoms. At present, the storage and transportation of hydrogen are difficult to overcome, and ammonia is considered to be the most potential zero-carbon fuel in the carbon neutral era due to its mature industrial preparation, convenient storage and transportation, and other advantages.

[0003] However, the high combustion inertia of ammonia itself makes it difficult to ignite, slow to burn, and low in combustion efficiency, which greatly limits the application of ammonia as a zero-carbon fuel in the field of internal combustion engines. In this context, international research on improving the combustion efficiency of ammonia has been carried out.

[0004] Adding high-activity hydrogen to the combustion process can reduce the ignition difficulty and improve the combustion speed, but the safety and cost problems brought by the existing hydrogen storage and transportation conditions greatly limit the application of on-board hydrogen. Considering that ammonia itself is a good carrier of hydrogen, using ammonia to generate hydrogen online becomes a potential solution. However, how to use ammonia to generate hydrogen and promote combustion while making minimal changes to existing engines and avoiding the high cost of catalysts and separation equipment has become an important research topic for internal combustion engines in the carbon neutral era. SUMMARY

[0005] Therefore, the present disclosure provides a combustion organization method and an internal combustion engine for implementing the combustion organization method, in order to at least partially solve the above technical problems.

[0006] In order to solve the above technical problems, the technical solutions of the present disclosure are as follows:

[0007] As one aspect of the present disclosure, a combustion organization method is provided, comprising:

[0008] In the intake phase of the first intake and exhaust cycle period of the internal combustion engine, a first mixture is introduced into the combustion chamber, wherein the composition of the first mixture includes fuel and air;

[0009] In the negative valve overlap phase of the first intake and exhaust cycle period of the internal combustion engine, ammonia is injected into the combustion chamber so that hydrogen is obtained after the thermal cracking reaction of ammonia with the first mixture and exhaust gas in the combustion chamber, wherein the negative valve overlap phase is a period when the intake valve and the exhaust valve are both closed;

[0010] In an intake phase of a second intake-exhaust cycle of the internal combustion engine, a second mixture is introduced into the combustion chamber so that the second mixture and the hydrogen gas are subjected to a reforming combustion in the combustion chamber, wherein the second mixture includes fuel and air.

[0011] According to an embodiment of the present disclosure, the injecting the ammonia into the combustion chamber includes:

[0012] The injecting the ammonia into the combustion chamber is performed once or multiple times.

[0013] According to an embodiment of the present disclosure, the fuel includes any one of:

[0014] Gasoline, diesel, ammonia.

[0015] According to an embodiment of the present disclosure, the ammonia includes: ammonia gas or liquid ammonia.

[0016] According to an embodiment of the present disclosure, the internal combustion engine includes any one of:

[0017] A gasoline internal combustion engine, a diesel internal combustion engine, an ammonia internal combustion engine.

[0018] According to an embodiment of the present disclosure, the introducing the second mixture into the combustion chamber includes:

[0019] The introducing the second mixture into the combustion chamber is performed at a ratio of 0.3-3 of a combustion equivalence ratio of the fuel and the air in the combustion chamber.

[0020] According to an embodiment of the present disclosure, the introducing the second mixture into the combustion chamber includes:

[0021] The introducing the second mixture into the combustion chamber is performed at a ratio of 0.3-0.9 of a combustion equivalence ratio of the fuel and the air in the combustion chamber in a case where the second mixture is subjected to a lean combustion reaction in the combustion chamber.

[0022] According to an embodiment of the present disclosure, the introducing the second mixture into the combustion chamber includes:

[0023] The introducing the second mixture into the combustion chamber is performed at a ratio of 1 of a combustion equivalence ratio of the fuel and the air in the combustion chamber in a case where the second mixture is subjected to a complete combustion reaction in the combustion chamber.

[0024] According to an embodiment of the present disclosure, the introducing the second mixture into the combustion chamber includes:

[0025] The introducing the second mixture into the combustion chamber is performed at a ratio of 1.1-3 of a combustion equivalence ratio of the fuel and the air in the combustion chamber in a case where the second mixture is subjected to a rich combustion reaction in the combustion chamber.

[0026] According to an embodiment of the present disclosure, in the case of using ammonia internal combustion engine, after the second mixture is introduced into the combustion chamber, ammonia is injected into the combustion chamber so that the ammonia mixes with the hydrogen and the second mixture to obtain ammonia-hydrogen mixture and is put into the reforming combustion.

[0027] According to an embodiment of the present disclosure, by controlling the proportion of ammonia injected into the combustion chamber in the negative valve overlap period of the first intake and exhaust cycle of the internal combustion engine and the intake stage of the second intake and exhaust cycle of the internal combustion engine respectively, different ammonia-hydrogen ratios can be obtained in the combustion chamber to meet the combustion requirements under different working conditions.

[0028] According to an embodiment of the present disclosure, the combustion products after the reforming combustion in the combustion chamber are discharged from the combustion chamber through the exhaust valve.

[0029] As another aspect of the present disclosure, an internal combustion engine for implementing the combustion organization method in the above-mentioned embodiments is provided, wherein the internal combustion engine comprises:

[0030] at least one combustion chamber for hydrogen obtained after the thermal cracking reaction of ammonia with the first mixture and exhaust gas in the combustion chamber, and for the reforming combustion of the second mixture with hydrogen;

[0031] at least one storage unit for storing ammonia;

[0032] at least one injection unit for injecting ammonia into the combustion chamber;

[0033] an intake and exhaust unit, the intake and exhaust unit comprises an intake valve and an exhaust valve, wherein the intake valve is used to inject the first mixture and the second mixture into the combustion chamber, and the exhaust valve is used to discharge the combustion products in the combustion chamber; the communication between the intake and exhaust unit and the combustion chamber is controlled by the intake valve and the exhaust valve; and

[0034] a pilot unit, the combustion chamber comprises at most one pilot unit for igniting the mixture in the combustion chamber.

[0035] According to an embodiment of the present disclosure, the way of supplying fuel into the combustion chamber comprises intake port direct injection or cylinder direct injection.

[0036] According to an embodiment of the present disclosure, in the case of supplying fuel into the combustion chamber by using the way of intake port direct injection, the internal combustion engine is equipped with a single direct injection injection unit for directly injecting ammonia into the combustion chamber in the negative valve overlap period so that hydrogen obtained after the thermal cracking reaction is used for reforming combustion.

[0037] According to an embodiment of the present disclosure, in the case of supplying fuel into the combustion chamber by using the way of cylinder direct injection, the internal combustion engine is equipped with a plurality of fuel nozzles, at least one of which is used to directly inject ammonia into the combustion chamber in the negative valve overlap period so that hydrogen obtained after the thermal cracking reaction is used for reforming combustion.

[0038] According to an embodiment of the present disclosure, the ignition mode of the ignition unit includes any one of a spark ignition mode, a jet ignition mode, and a compression ignition mode.

[0039] According to an embodiment of the present disclosure, in the case of using the spark ignition mode, the internal combustion engine includes at least one spark plug.

[0040] According to an embodiment of the present disclosure, in the case of using the jet ignition mode, the internal combustion engine includes at least one jet cavity.

[0041] According to an embodiment of the present disclosure, in the case of using the compression ignition mode, the internal combustion engine does not install a spark plug.

[0042] Based on the above technical solution, the present disclosure provides a combustion organization method and an internal combustion engine for implementing the combustion organization method, which at least have the following beneficial effects:

[0043] (1) According to an embodiment of the present disclosure, in the intake stage of the first intake cycle of the internal combustion engine, a first mixture containing fuel and air is introduced into the combustion chamber; the first mixture is mixed with the exhaust gas generated in the combustion chamber in the previous cycle, at this time, the combustion chamber is in a high-temperature and high-pressure, oxygen-poor environment, and then the intake valve is closed. There is a negative valve overlap stage in the period when the intake valve and the exhaust valve of the internal combustion engine are closed, at this stage, because the inside of the combustion chamber of the internal combustion engine is still in a high-temperature and high-pressure state, it is equivalent to a high-temperature and high-pressure reactor. At this time, ammonia is injected into the combustion chamber, and the injected ammonia is mixed with the first mixture and the exhaust gas in the combustion chamber, so that the ammonia undergoes a thermal cracking reaction under the high-temperature and high-pressure environment caused by combustion and high-temperature exhaust gas to obtain hydrogen. The converted ammonia does not pass through the separation device of the internal combustion engine and is extracted, but is directly retained in the combustion chamber to wait for the combustion of the next cycle. At the beginning of the next cycle combustion, in the intake stage of the second intake cycle of the internal combustion engine, a second mixture containing fuel and air is introduced into the combustion chamber, the second mixture is mixed with the hydrogen generated in the negative valve overlap stage to form a new mixture and perform reforming combustion in the combustion chamber.

[0044] (2) The combustion organization method provided by the present disclosure can realize the negative valve overlap function of the internal combustion engine and the exhaust gas recirculation in the combustion chamber by adjusting the closing or opening of the intake and exhaust valves based on the existing internal combustion engine. By injecting ammonia into the combustion chamber of the internal combustion engine during the negative valve overlap stage, the exhaust gas generated during the negative valve overlap stage of the previous combustion cycle and the first mixture are mixed, and the high-temperature and high-pressure lean oxygen environment formed by re-compression can realize the thermal cracking of ammonia to obtain hydrogen, and the hydrogen obtained by the decomposition of ammonia can be directly used for the next combustion cycle of the internal combustion engine. Compared with the existing hydrogen production device, the method provided by the present disclosure does not need to use a catalyst and a hydrogen separation device, reduces the hydrogen production cost, simplifies the hydrogen production safety process, and can effectively improve the combustion efficiency of the internal combustion engine without modifying the structure of the internal combustion engine. In addition, the combustion organization method provided by the present disclosure can dilute the first mixture by the exhaust gas in the combustion chamber, reduce the concentration of oxygen, and inhibit the generation of nitrogen oxides.

[0045] (3) According to the embodiment of the present disclosure, by controlling the injection amount and injection times of ammonia injected into the combustion chamber during the negative valve overlap stage, the internal combustion engine can realize on-line hydrogen production and improve the combustion of the internal combustion engine. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 A principle diagram of the combustion organization method according to an embodiment of the present disclosure is shown;

[0047] Figure 2A A schematic diagram of single-ammonia injection during the negative valve overlap stage in the entire intake and exhaust cycle of the internal combustion engine is shown;

[0048] Figure 2B A schematic diagram of multiple-ammonia injection during the negative valve overlap stage in the entire intake and exhaust cycle of the internal combustion engine is shown;

[0049] Figure 3 A principle diagram of the combustion organization method according to another embodiment of the present disclosure is shown;

[0050] Figure 4 A structural schematic diagram of the intake and exhaust structure of the internal combustion engine for realizing the combustion organization method according to the embodiment of the present disclosure is shown.

[0051] REFERENCE SIGNS

[0052] 1 - intake valve, 2 - exhaust valve, 3 - injection unit, 4 - pilot unit, 5 - combustion chamber, 6 - storage unit. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the drawings.

[0054] An aspect of the present disclosure provides a combustion organization method, comprising:

[0055] In an intake phase of a first intake-exhaust cycle of the internal combustion engine, a first mixture is introduced into the combustion chamber, wherein the first mixture comprises fuel and air;

[0056] In a negative valve overlap phase of the first intake-exhaust cycle of the internal combustion engine, ammonia is injected into the combustion chamber so that the ammonia and the first mixture and the exhaust gas in the combustion chamber undergo a thermal cracking reaction to obtain hydrogen, wherein the negative valve overlap phase is a period when the intake valve and the exhaust valve are both closed;

[0057] In an intake phase of a second intake-exhaust cycle of the internal combustion engine, a second mixture is introduced into the combustion chamber so that the second mixture and the hydrogen undergo a reforming combustion in the combustion chamber, wherein the second mixture comprises fuel and air.

[0058] Figure 1 A schematic diagram of a combustion organization method according to an embodiment of the present disclosure is shown.

[0059] The following describes Figure 1 a combustion organization method according to an embodiment of the present disclosure.

[0060] As shown in Figure 1 , the intake valve of the internal combustion engine is opened, and in an intake phase of a first intake-exhaust cycle of the internal combustion engine, a first mixture is introduced into the combustion chamber, wherein the first mixture comprises fuel and air. Then, the intake valve of the internal combustion engine is closed, at this time, the combustion chamber of the internal combustion engine is a high-temperature and high-pressure environment, equivalent to a high-temperature and high-pressure reactor, and in a negative valve overlap phase of the first intake-exhaust cycle of the internal combustion engine, ammonia is injected into the combustion chamber, wherein the ammonia can be ammonia gas or liquid ammonia, so that the ammonia and the first mixture and the exhaust gas in the combustion chamber undergo a thermal cracking reaction to obtain hydrogen, and the generated hydrogen is directly retained in the combustion chamber to wait for combustion in the next cycle, wherein the negative valve overlap phase is a period when the intake valve and the exhaust valve are both closed. Next, at the beginning of the next cycle combustion, in an intake phase of a second intake-exhaust cycle of the internal combustion engine, a second mixture is introduced into the combustion chamber, so that the second mixture and the hydrogen are mixed to form a new mixture, when the new mixture reaches the ignition point, ignition is performed, and the new mixture undergoes a reforming combustion in the combustion chamber to increase the pressure in the combustion chamber and perform work on the outside.

[0061] In the embodiments of the present disclosure, based on the existing internal combustion engine, the exhaust gas recirculation in the combustion chamber is realized by controlling the opening or closing of the intake and exhaust valves in the negative valve overlap stage. The first mixture is introduced into the combustion chamber in the intake stage of the first intake and exhaust cycle of the internal combustion engine, and the first mixture is mixed with the exhaust gas generated by the combustion in the last cycle, and then the intake valve is closed. At this time, the combustion chamber is in a high-temperature and high-pressure and oxygen-poor environment. There is a negative valve overlap stage when the intake and exhaust valves of the internal combustion engine are both closed. At this stage, the combustion chamber is equivalent to a high-temperature and high-pressure reactor due to the high-temperature and high-pressure and oxygen-poor environment of the combustion chamber. At this time, ammonia is injected into the combustion chamber of the internal combustion engine, and the injected ammonia undergoes a thermal cracking reaction in the high-temperature and high-pressure environment due to combustion and high-temperature exhaust gas to obtain hydrogen. The hydrogen produced by the thermal cracking conversion of the injected ammonia is not extracted by the separation device of the internal combustion engine, but is directly retained in the combustion chamber and used for combustion in the next cycle. At the beginning of the next cycle, the second mixture is introduced into the combustion chamber in the intake stage of the second intake and exhaust cycle of the internal combustion engine. The second mixture introduced into the combustion chamber is mixed with hydrogen. Due to the presence of hydrogen, which has higher activity than the second mixture, the speed and efficiency of combustion can be effectively improved when the combustion chamber is subjected to reforming combustion. Compared with the existing hydrogen production device, the internal combustion engine in the technical solution of the present disclosure does not need to use a catalyst and a hydrogen separation device to obtain hydrogen, thereby reducing the cost of hydrogen production, simplifying the hydrogen production process, and improving the combustion efficiency of the internal combustion engine without changing the structure of the internal combustion engine.

[0062] According to the embodiments of the present disclosure, injecting ammonia into the combustion chamber includes single injection of ammonia into the combustion chamber or multiple injection of ammonia into the combustion chamber.

[0063] Figure 2A A schematic diagram of single injection of ammonia in the negative valve overlap stage in the entire intake and exhaust cycle of the internal combustion engine is shown; Figure 2B A schematic diagram of multiple injection of ammonia in the negative valve overlap stage in the entire intake and exhaust cycle of the internal combustion engine is shown.

[0064] As shown in Figure 2A and Figure 2B , there is a negative valve overlap stage before the intake valve is opened (IVO) and during the period when the exhaust valve is closed (EVC). At this stage, the combustion chamber is in a high-temperature and high-pressure state. Single injection of ammonia into the combustion chamber or multiple injection of ammonia into the combustion chamber can improve the rate and efficiency of combustion of the internal combustion engine. Single injection of ammonia into the combustion chamber means that ammonia is injected once. Multiple injection of ammonia into the combustion chamber means that ammonia is injected multiple times. The number of times of multiple injection of ammonia is not limited to twice. The content of hydrogen produced by the thermal cracking reaction of ammonia in the combustion chamber can be controlled by controlling the amount of ammonia injected each time or the number of times of ammonia injection.

[0065] Figure 2A and Figure 2B The 2nd phase in the above represents the phase from Intake Valve Open (IVO) to Intake Valve Close (IVC), and the 1st phase represents the phase from Exhaust Valve Close (EVC) to Exhaust Valve Open (EVO). In combination with Figure 1 and Figures 2A-2B The change process of the opening or closing of the intake valve and the exhaust valve of the internal combustion engine during the combustion process is described as follows:

[0066] When the piston of the internal combustion engine moves from the top dead center (TDC) to the bottom dead center (BDC), the intake valve of the internal combustion engine is in an open state, the exhaust valve is in a closed state, the volume above the piston is increased, the pressure of the combustion chamber is reduced, a certain vacuum suction force is generated, the first mixture is sucked into the combustion chamber, the first mixture sucked into the combustion chamber is mixed with the exhaust gas generated in the combustion chamber in the previous combustion cycle, and the combustion chamber at this time is in a high-temperature and high-pressure and oxygen-poor environment. When the piston moves to the bottom dead center, the intake valve is closed. After the piston completes the first stroke, the intake valve and the exhaust valve are both in a closed state, that is, the internal combustion engine is in a negative valve overlap stage, and the process in which the piston moves from the bottom dead center to the top dead center is a compression stroke. Because the internal combustion chamber is still in a high-temperature and high-pressure state, ammonia is injected into the combustion chamber in this stage, the ammonia is mixed with the exhaust gas and the first mixture in the combustion chamber, and hydrogen is obtained after the ammonia is subjected to a thermal cracking reaction in a high-temperature and high-pressure environment caused by combustion and high-temperature exhaust gas. The ammonia injection into the combustion chamber includes single injection or multiple injections. Then, the piston continues to move downward to the bottom dead center, the intake valve is opened, and the exhaust valve is in a closed state, so that the fuel and air (second mixture) are introduced into the combustion chamber to be mixed with the hydrogen in the combustion chamber and to combust in the combustion chamber. Then, the intake valve is closed, the piston moves from the bottom dead center to the top dead center, and the igniter ignites the combustible mixture (fuel, air and hydrogen) compressed in the combustion chamber. After the combustible mixture burns, a large amount of heat is released, the pressure and temperature of the combustion chamber rapidly rise, the high-temperature and high-pressure gas pushes the piston to move rapidly to the bottom dead center, and the crank connecting rod mechanism works externally. After the work is completed, the exhaust stroke is entered, the exhaust valve is opened, and because the pressure in the combustion chamber at this time is higher than the atmospheric pressure, the high-temperature exhaust gas is rapidly discharged from the cylinder through the exhaust valve. With the progress of the exhaust process, the forced exhaust stage is entered, the piston moves upward to the top dead center, and the exhaust gas in the cylinder is forced to be discharged. When the piston reaches the top dead center, the exhaust process is completed. Because the combustion chamber has a certain volume, it is not possible to completely remove the exhaust gas at the end of the exhaust, and the remaining exhaust gas can provide a high-temperature and high-pressure environment for the negative valve overlap stage of the next combustion cycle.

[0067] Recombination Figure 1 When ammonia is injected into the combustion chamber multiple times, the pressure in the combustion chamber of the internal combustion engine is higher than that when ammonia is injected into the combustion chamber single time, which indicates that the hydrogen generation rate can be effectively accelerated, and the combustion speed and combustion efficiency can be optimized.

[0068] According to the embodiments of the present disclosure, the fuel includes any one of gasoline, diesel and ammonia, and the internal combustion engine includes any one of a gasoline internal combustion engine, a diesel internal combustion engine and an ammonia internal combustion engine. The ammonia includes ammonia gas or liquid ammonia. It should be noted that the internal combustion engine used in the present disclosure is not limited to the examples.

[0069] According to an embodiment of the present disclosure, the second mixture is introduced into the combustion chamber, including:

[0070] The second mixture is introduced into the combustion chamber at a ratio of 0.3-3 of the equivalence ratio of fuel and air in the combustion chamber. By controlling the ratio of fuel and air in the second mixture, the fuel in the combustion chamber is combusted to different degrees to meet the needs of different internal combustion engines.

[0071] For example, in the case of lean combustion reaction of the second mixture in the combustion chamber, the second mixture is introduced into the combustion chamber at a ratio of 0.3-0.9 of the equivalence ratio of fuel and air in the combustion chamber, so as to meet the needs of different internal combustion engines or different scenarios of the internal combustion engine, such as the needs of clean internal combustion engine applications with relatively low energy consumption or application scenarios of the internal combustion engine during downhill.

[0072] In the case of complete combustion reaction of the second mixture in the combustion chamber, the second mixture is introduced into the combustion chamber at a ratio of 1 of the equivalence ratio of fuel and air in the combustion chamber, so as to meet the needs of different internal combustion engines and different application scenarios of the internal combustion engine.

[0073] In the case of over-rich combustion reaction of the second mixture in the combustion chamber, the second mixture is introduced into the combustion chamber at a ratio of 1.1-3 of the equivalence ratio of fuel and air in the combustion chamber, so as to meet the needs of internal combustion engines that need to consume too much fuel or different scenarios of the internal combustion engine, such as application scenarios of gasoline internal combustion engines or internal combustion engines during uphill.

[0074] According to an embodiment of the present disclosure, in the case of using an ammonia internal combustion engine, after the second mixture is introduced into the combustion chamber, ammonia is sprayed into the combustion chamber, so that the ammonia is mixed with hydrogen and the second mixture to obtain ammonia-hydrogen mixed gas and is subjected to modified combustion. The process of the specific combustion organization method is as shown in Figure 3 .

[0075] Figure 3 The principle diagram of the combustion organization method for realizing another embodiment of the present disclosure is shown.

[0076] The following Figure 3 The specific process of using ammonia as a single-fuel combustion chamber and using in-cylinder direct injection of ammonia to perform single-cycle combustion organization in an embodiment of the present disclosure is described in detail below.

[0077] As Figure 3As shown, in the negative valve overlap stage of the first intake and exhaust cycle of the ammonia internal combustion engine, ammonia is single-injected into the combustion chamber, and the ammonia is thermally decomposed into hydrogen in the high-temperature and high-pressure environment in the combustion chamber and directly remains in the combustion chamber to wait for combustion in the next cycle. At the start of the next cycle, in the intake stage of the second intake and exhaust cycle of the internal combustion engine, after the second mixture is introduced into the combustion chamber, ammonia is again injected into the combustion chamber, the injected ammonia is mixed with the air, fuel (ammonia) and hydrogen generated in the negative valve overlap stage in the second mixture in the combustion chamber to obtain a mixture containing ammonia and hydrogen, and the mixture is put into combustion. Due to the addition of hydrogen, the ammonia and hydrogen mixture in this cycle has higher activity than pure ammonia, and thus the combustion rate and combustion efficiency of the ammonia internal combustion engine can be improved.

[0078] According to an embodiment of the present disclosure, taking an ammonia internal combustion engine as an example, by controlling the proportion of ammonia injection into the combustion chamber in the negative valve overlap stage of the first intake and exhaust cycle of the internal combustion engine and in the intake stage of the second intake and exhaust cycle of the internal combustion engine, respectively, different ammonia and hydrogen ratios can be obtained in the combustion chamber to meet the combustion requirements under different working conditions. For example, when the internal combustion engine needs greater power demand (climbing), over-rich combustion is generally required in the combustion chamber, and at this time, compared with other working conditions, more ammonia needs to be injected into the combustion chamber (as fuel) in the negative valve overlap stage of the first intake and exhaust cycle and in the intake stage of the second intake and exhaust cycle to ensure that there is enough ammonia to generate more hydrogen through thermal cracking in the negative valve overlap stage, and to ensure that there is enough hydrogen to promote the combustion of ammonia, thereby improving the overall combustion efficiency of the ammonia internal combustion engine.

[0079] According to an embodiment of the present disclosure, the combustion products after the reforming combustion in the combustion chamber are discharged from the combustion chamber through the exhaust valve, for example, the gases such as carbon dioxide and nitrogen oxides generated after combustion are discharged from the combustion chamber through the exhaust valve.

[0080] According to an embodiment of the present disclosure, an internal combustion engine for implementing the combustion organization method is also provided, which comprises at least one combustion chamber, at least one storage unit, at least one injection unit, an intake and exhaust unit, and a pilot unit.

[0081] The at least one combustion chamber is used for ammonia to react with a first mixture in the combustion chamber and exhaust gas to generate hydrogen, and is used for a second mixture to perform reforming combustion with the hydrogen.

[0082] The at least one storage unit is used for storing ammonia.

[0083] The intake and exhaust unit comprises an intake valve and an exhaust valve, wherein the intake valve is used for injecting the first mixture and the second mixture into the combustion chamber, and the exhaust valve is used for discharging the products of combustion in the combustion chamber; the communication between the intake and exhaust unit and the combustion chamber is controlled through the intake valve and the exhaust valve.

[0084] The combustion chamber includes at most one pilot unit for igniting the mixture in the combustion chamber.

[0085] Figure 4 A structural diagram of an internal combustion engine intake and exhaust structure for implementing the combustion organization method in the embodiments of the present disclosure is shown.

[0086] As shown in Figure 4 The internal combustion engine includes an intake and exhaust unit, a spray unit 3, a pilot unit 4, a combustion chamber 5, and a storage unit 6, wherein the intake and exhaust unit includes an intake valve 1 and an exhaust valve 2.

[0087] The combustion chamber 5 is used for the thermal cracking reaction of ammonia and the first mixture to obtain hydrogen, and is used for the reforming combustion of the second mixture and hydrogen.

[0088] The storage unit 6 is used for storing ammonia, wherein the ammonia includes ammonia gas or liquid ammonia.

[0089] The spray unit 3 is used for spraying ammonia into the combustion chamber 5.

[0090] The intake and exhaust unit includes an intake valve 1 and an exhaust valve 2, wherein the intake valve 1 is used for spraying the first mixture and the second mixture into the combustion chamber 5, and the exhaust valve 2 is used for discharging the products of combustion in the combustion chamber 5; the communication between the intake and exhaust unit and the combustion chamber 5 is controlled by the intake valve 1 and the exhaust valve 2.

[0091] The pilot unit 4 is used for igniting the mixture in the combustion chamber 5, wherein the mixture can be the mixture of the second mixture and hydrogen.

[0092] According to the embodiments of the present disclosure, the way of supplying fuel into the combustion chamber 5 includes intake port injection or in-cylinder direct injection. When the intake port injection is used, the fuel is sprayed in the intake port, mainly relying on the wall temperature and the temperature of the exhaust gas backflow when the intake valve is opened to promote the evaporation of the fuel, so as to mix with the air to form a combustible mixture; when the in-cylinder direct injection is used, the fuel is directly sprayed into the combustion chamber, and the sprayed fuel mixes with the air entering the combustion chamber to form a combustible mixture.

[0093] According to the embodiments of the present disclosure, in the case of supplying fuel into the combustion chamber 5 by using the intake port direct injection method, the internal combustion engine is equipped with a single direct injection spray unit, which is used for directly spraying ammonia into the combustion chamber during the negative valve overlap period, so as to obtain hydrogen by thermal cracking reaction for reforming combustion.

[0094] According to the embodiments of the present disclosure, in the case of supplying fuel into the combustion chamber 5 in the way of in-cylinder direct injection, the internal combustion engine is equipped with a plurality of fuel injectors, at least one of which serves as a jetting unit for directly jetting ammonia into the combustion chamber 5 in the negative valve overlap period so as to be reformed by the thermal cracking reaction to obtain hydrogen for combustion.

[0095] According to the embodiments of the present disclosure, the pilot mode of the pilot unit 4 includes any one of spark ignition mode, jet pilot mode, and compression ignition pilot mode. It should be noted that the pilot mode of the internal combustion engine is not limited to the ones listed in the present disclosure.

[0096] According to the embodiments of the present disclosure, in the case of using the spark ignition mode for pilot, the internal combustion engine includes at least one spark plug; in the case of using the jet pilot mode, the internal combustion engine includes at least one jet chamber. In the case of using the compression ignition pilot mode for pilot, the internal combustion engine is not equipped with a spark plug.

[0097] It should be noted that the above-mentioned Figure 4 are only examples. As mentioned above, the present disclosure can be applied to internal combustion engines with negative valve overlap function of different fuel basis, different ignition mode, different jetting strategy, and the number of combustion chambers, jetting units, and storage units in the internal combustion engine is not limited to the ones shown in the figures. Figure 4 The above-mentioned specific embodiments are only examples.

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Claims

1. A method of organizing combustion, characterized by, The method comprises: in the intake phase of the first intake-exhaust cycle of the internal combustion engine, a first mixture is introduced into the combustion chamber, wherein the first mixture comprises fuel and air; in the negative valve overlap phase of the first intake-exhaust cycle of the internal combustion engine, ammonia is injected into the combustion chamber, so that the ammonia and the first mixture in the combustion chamber and the oxygen-poor environment formed by the exhaust gas in the negative valve overlap phase undergo a thermal cracking reaction to obtain hydrogen gas, wherein the negative valve overlap phase is a period when the intake valve and the exhaust valve are both closed; in the intake phase of the second intake-exhaust cycle of the internal combustion engine, a second mixture is introduced into the combustion chamber, so that the second mixture and the hydrogen gas undergo a reforming combustion in the combustion chamber, wherein the second mixture comprises fuel and air, and the fuel comprises any one of gasoline, diesel, and ammonia; the negative valve overlap function of the internal combustion engine and the exhaust gas recirculation in the combustion chamber are achieved by adjusting the closing or opening of the intake valve and the exhaust valve; wherein the combustion organization method does not use a hydrogen separation device.

2. The method of claim 1, wherein, The injection of ammonia into the combustion chamber comprises: single injection of ammonia into the combustion chamber or multiple injections of ammonia into the combustion chamber.

3. The method of claim 1, wherein, The ammonia comprises: ammonia gas or liquid ammonia.

4. The method of claim 1, wherein, The internal combustion engine comprises any one of: a gasoline internal combustion engine, a diesel internal combustion engine, and an ammonia internal combustion engine.

5. The method of claim 1, wherein, The introduction of the second mixture into the combustion chamber comprises: introducing the second mixture into the combustion chamber at a ratio of 0.3-3 of the equivalence ratio of fuel and air in the combustion chamber.

6. The method according to claim 1 or 5, characterized in that, The introduction of the second mixture into the combustion chamber comprises: in the case that the second mixture undergoes a lean combustion reaction in the combustion chamber, introducing the second mixture into the combustion chamber at a ratio of 0.3-0.9 of the equivalence ratio of fuel and air in the combustion chamber.

7. The method according to claim 1 or 5, characterized in that, The introduction of the second mixture into the combustion chamber comprises: in the case that the second mixture undergoes a complete combustion reaction in the combustion chamber, introducing the second mixture into the combustion chamber at a ratio of 1 of the equivalence ratio of fuel and air in the combustion chamber.

8. The method of claim 5, wherein, The introduction of the second mixture into the combustion chamber comprises: in the case that the second mixture undergoes a rich combustion reaction in the combustion chamber, introducing the second mixture into the combustion chamber at a ratio of 1.1-3 of the equivalence ratio of fuel and air in the combustion chamber.

9. The method according to claim 4, wherein in the case of using an ammonia internal combustion engine, after the second mixture is introduced into the combustion chamber, ammonia is injected into the combustion chamber, so that the ammonia mixes with the hydrogen gas and the second mixture to obtain ammonia-hydrogen mixed gas and undergoes reforming combustion.

10. The method according to claim 9, wherein by controlling the proportion of ammonia injected into the combustion chamber in the negative valve overlap phase of the first intake-exhaust cycle of the internal combustion engine and in the intake phase of the second intake-exhaust cycle of the internal combustion engine, respectively, different ammonia-hydrogen ratios can be obtained in the combustion chamber to meet the combustion requirements under different working conditions.

11. The method according to claim 1, wherein The combustion products after the reformed combustion in the combustion chamber are discharged from the combustion chamber through the exhaust valve.

12. An internal combustion engine for implementing the combustion organization method according to any one of claims 1 to 11, characterized by, The internal combustion engine comprises: at least one combustion chamber for the thermal cracking reaction of ammonia with a first mixture and exhaust gas in the combustion chamber to obtain hydrogen, and for the reformed combustion of the second mixture with the hydrogen; at least one storage unit for storing ammonia; at least one injection unit for injecting ammonia into the combustion chamber; an intake and exhaust unit, which comprises an intake valve and an exhaust valve, wherein the intake valve is used to inject the first mixture and the second mixture into the combustion chamber, and the exhaust valve is used to discharge the combustion products in the combustion chamber; the communication between the intake and exhaust unit and the combustion chamber is controlled through the intake valve and the exhaust valve, and the negative valve overlap function of the internal combustion engine and the exhaust gas recirculation in the combustion chamber are realized by adjusting the closing or opening of the intake valve and the exhaust valve; and an ignition unit, which comprises at most one ignition unit in the combustion chamber, and is used to ignite the mixture in the combustion chamber.

13. The internal combustion engine according to claim 12, characterized by The way of supplying fuel into the combustion chamber comprises port injection or direct injection.

14. The internal combustion engine according to claim 13, wherein, in the case of supplying fuel into the combustion chamber by using the port injection, the internal combustion engine is equipped with a single direct injection injection unit, which is used to directly inject ammonia into the combustion chamber during the negative valve overlap period, so as to obtain hydrogen through the thermal cracking reaction for reformed combustion.

15. The internal combustion engine according to claim 13, wherein, in the case of supplying fuel into the combustion chamber by using the direct injection, the internal combustion engine is equipped with a plurality of fuel nozzles, wherein at least one fuel nozzle is used to directly inject ammonia into the combustion chamber during the negative valve overlap period, so as to obtain hydrogen through the thermal cracking reaction for reformed combustion.

16. The internal combustion engine of claim 12, wherein The ignition mode of the ignition unit comprises any one of spark ignition mode, jet ignition mode and compression ignition mode.

17. The internal combustion engine of claim 16, wherein In the case of using the spark ignition mode, the internal combustion engine comprises at least one spark plug.

18. The internal combustion engine of claim 16, wherein In the case of using the jet ignition mode, the internal combustion engine comprises at least one jet cavity.

19. The internal combustion engine of claim 16, wherein In the case of using the compression ignition mode for ignition, the internal combustion engine is not equipped with a spark plug.

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