Control method of ammonia-hydrogen engine, ammonia-hydrogen engine and combustion system of ammonia-hydrogen engine

Abstract

The invention relates to the technical field of new energy engines, in particular to a control method of an ammonia-hydrogen engine, the ammonia-hydrogen engine and a combustion system of the ammonia-hydrogen engine. According to the control method, the starting working condition and the operation working condition of the engine are optimized. When the engine is in a starting working condition, the motor is controlled to drive the crankshaft to rotate, and hydrogen is used as fuel, so that a hydrogen and air mixed gas environment is formed in the combustion chamber, and the ammonia-hydrogen engine is in idling operation, so that the ammonia-hydrogen engine is easy to start quickly; and after the engine is successfully started, the motor is disconnected, ammonia and hydrogen are used as fuel, a hydrogen, ammonia and air mixed gas environment is formed in the combustion chamber, the ammonia-hydrogen engine is out of idling operation, and therefore the use cost of the ammonia-hydrogen engine is reduced. And when the engine is in the operation working condition, the first temperature of cooling liquid used by the ammonia-hydrogen engine and / or the second temperature of lubricating oil are / is obtained, the ammonia-hydrogen engine is adjusted to the corresponding working condition according to the first temperature and / or the second temperature, and the heat efficiency of the ammonia-hydrogen engine is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy engines, and in particular to a control method of an ammonia-hydrogen engine, an ammonia-hydrogen engine and a combustion system thereof. Background Art

[0002] In recent years, internal combustion engines using ammonia fuel and hydrogen fuel have received widespread attention from industry and academia. Existing studies have shown that the use of a small amount of hydrogen (energy ratio less than 3%) can achieve stable operation of ammonia-hydrogen engines. Considering that the cost of ammonia is lower than that of hydrogen, the lower hydrogen energy ratio in ammonia-hydrogen fuel helps to reduce the overall fuel cost and is conducive to technology promotion. It should be pointed out that ammonia has low activity and is difficult to burn, making it difficult to be used for cold start or low-load conditions. Hydrogen is extremely active and prone to pre-ignition, which poses a challenge to efficient and stable operation under high-load conditions. However, ammonia has strong anti-knock properties, which is conducive to achieving high-load engine combustion without detonation. Hydrogen has a low minimum ignition energy and a short flame quenching distance, which can achieve stable operation of the engine under low load.

[0003] For ammonia-hydrogen engines, since ammonia fuel is not suitable for starting conditions, hydrogen fuel is not suitable for high-load conditions, and hydrogen fuel is expensive, how to adjust the combustion strategy of ammonia-hydrogen engines to improve combustion efficiency and reduce costs is an urgent problem to be solved. Summary of the invention

[0004] The present invention provides a control method of an ammonia-hydrogen engine, an ammonia-hydrogen engine and a combustion system thereof, so as to solve the defects in the prior art that ammonia fuel in an ammonia-hydrogen engine is not suitable for starting conditions, hydrogen fuel is not suitable for high-load conditions, and the cost of hydrogen fuel is high.

[0005] The present invention provides a control method for an ammonia-hydrogen engine, comprising: When the ammonia hydrogen engine is in the starting condition, it includes: S1. Control the motor to drive the crankshaft to rotate, use hydrogen as fuel, so that a hydrogen and air mixture environment is formed in the combustion chamber, and the ammonia hydrogen engine is in idle operation; S2. After the ammonia-hydrogen engine is successfully started, the motor is disconnected, and ammonia and hydrogen are used as fuel, so that a mixture of hydrogen, ammonia and air is formed in the combustion chamber, and the ammonia-hydrogen engine stops idling; When the ammonia hydrogen engine is in operation, it includes: S3. Obtain a first temperature of a coolant and / or a second temperature of a lubricating oil used by the ammonia-hydrogen engine, and adjust the ammonia-hydrogen engine to a corresponding operating condition according to the first temperature and / or the second temperature.

[0006] According to the control method of the ammonia-hydrogen engine of the present invention, when the ammonia-hydrogen engine is in an operating condition, and after the step of obtaining the first temperature of the coolant used by the ammonia-hydrogen engine and / or the second temperature of the lubricating oil, and adjusting the ammonia-hydrogen engine to a corresponding operating condition according to the first temperature and / or the second temperature, the method further includes: S4. Obtain the current cycle fluctuation rate of the ammonia-hydrogen engine, and adjust the operating condition of the ammonia-hydrogen engine according to the current cycle fluctuation rate of the ammonia-hydrogen engine.

[0007] According to the control method of the ammonia-hydrogen engine of the present invention, the step of obtaining the current cycle fluctuation rate of the ammonia-hydrogen engine and adjusting the operating condition of the ammonia-hydrogen engine according to the current cycle fluctuation rate of the ammonia-hydrogen engine specifically includes: S41, presetting a maximum value of the cyclic volatility and a minimum value of the cyclic volatility; S42, if the current cycle fluctuation rate of the ammonia-hydrogen engine is between the preset cycle fluctuation rate maximum value and the cycle fluctuation rate minimum value, then maintaining the current operating condition of the ammonia-hydrogen engine; If the current cycle fluctuation rate of the ammonia hydrogen engine is greater than the preset maximum cycle fluctuation rate, the energy proportion of hydrogen in the fuel is increased; If the current cycle fluctuation rate of the ammonia hydrogen engine is less than the preset minimum cycle fluctuation rate, the energy proportion of hydrogen in the fuel is reduced.

[0008] According to the control method of the ammonia-hydrogen engine of the present invention, if the current cycle fluctuation rate of the ammonia-hydrogen engine is greater than the preset maximum cycle fluctuation rate, the energy proportion of hydrogen in the fuel is increased to 100%; if the cycle fluctuation rate of the ammonia-hydrogen engine is still greater than the preset maximum cycle fluctuation rate, the operating power and / or speed of the ammonia-hydrogen engine is reduced until the cycle fluctuation rate is less than the preset maximum cycle fluctuation rate.

[0009] According to the control method of the ammonia-hydrogen engine of the present invention, when the ammonia-hydrogen engine is in a starting condition, the control method specifically includes: Determine that the excess air coefficient of the ammonia-hydrogen engine is 1.0~2.5, and when the ammonia-hydrogen engine indicates a mean effective pressure of less than 0.6MPa, determine that the ammonia-hydrogen engine is idling under a low load condition; when the ammonia-hydrogen engine indicates a mean effective pressure greater than 0.9MPa and less than 1.2MPa, determine that the ammonia-hydrogen engine is in a medium-to-high load condition and is out of idling.

[0010] According to the control method of the ammonia hydrogen engine of the present invention, the preset maximum value of the cycle fluctuation rate ranges from 4% to 6%, and the preset minimum value of the cycle fluctuation rate ranges from 0.5% to 2%.

[0011] The present invention also provides an ammonia hydrogen engine, comprising: a combustion chamber, an intake passage, an exhaust passage, a spark plug, an ammonia pressure reducing valve, an ammonia booster pump, a hydrogen pressure reducing valve, an ammonia injector, a hydrogen injector and a controller; The intake passage and the exhaust passage are communicated with the combustion chamber respectively, the ammonia injector and the hydrogen injector are both connected to the same intake passage, the spark plug extends to the combustion chamber, the ammonia pressure reducing valve and the ammonia booster pump are connected in parallel between the ammonia storage tank and the ammonia injector, and the hydrogen pressure reducing valve is connected between the hydrogen storage tank and the hydrogen injector; The controller executes the control method of the ammonia-hydrogen engine of the present invention and is electrically connected to the ammonia pressure reducing valve, the ammonia boost pump, the hydrogen pressure reducing valve, the ammonia injector, the hydrogen injector and the spark plug.

[0012] According to the ammonia-hydrogen engine provided by the present invention, the compression ratio of the ammonia-hydrogen engine is 20-25; the injection pressure of the ammonia injector is 0.4-30 MPa.

[0013] The present invention also provides an ammonia hydrogen engine, comprising: a combustion chamber, an intake passage, an exhaust passage, a spark plug, an ammonia pressure reducing valve, an ammonia booster pump, a hydrogen pressure reducing valve, an ammonia injector, a hydrogen injector and a controller; The intake passage and the exhaust passage are communicated with the combustion chamber respectively, the ammonia injector and the hydrogen injector are led to different intake passages respectively, the spark plug extends to the combustion chamber, the ammonia pressure reducing valve and the ammonia booster pump are connected in parallel between the ammonia storage tank and the ammonia injector, and the hydrogen pressure reducing valve is connected between the hydrogen storage tank and the hydrogen injector; The controller executes the control method of the ammonia-hydrogen engine of the present invention and is electrically connected to the ammonia pressure reducing valve, the ammonia boost pump, the hydrogen pressure reducing valve, the ammonia injector, the hydrogen injector and the spark plug.

[0014] According to the ammonia-hydrogen engine provided by the present invention, the compression ratio of the ammonia-hydrogen engine is 20-25; the injection pressure of the ammonia injector is 0.4-30 MPa.

[0015] The present invention also provides a combustion system of an ammonia-hydrogen engine, comprising: an ammonia storage tank, an ammonia pipeline, a hydrogen storage tank, a hydrogen pipeline and the ammonia-hydrogen engine of the present invention; The ammonia storage tank is connected to the ammonia injector through the ammonia pipeline, and the hydrogen storage tank is connected to the hydrogen injector through the hydrogen pipeline.

[0016] The present invention provides a control method for an ammonia-hydrogen engine, which optimizes the control method when the ammonia-hydrogen engine is in a starting condition and in an operating condition. When the ammonia-hydrogen engine is in a starting condition, the motor is controlled to drive the crankshaft to rotate, and hydrogen is used as fuel, so that a hydrogen and air mixed gas environment is formed in the combustion chamber, and the ammonia-hydrogen engine is in an idling operation, so that the ammonia-hydrogen engine is easy to start quickly; after the ammonia-hydrogen engine is successfully started, the motor is disconnected, and ammonia and hydrogen are used as fuels, so that a hydrogen, ammonia and air mixed gas environment is formed in the combustion chamber, and the ammonia-hydrogen engine is out of idling operation, thereby reducing the use cost of the ammonia-hydrogen engine. When the ammonia-hydrogen engine is in an operating condition, the first temperature of the coolant used by the ammonia-hydrogen engine and / or the second temperature of the lubricating oil are obtained, and according to the first temperature and / or the second temperature, the ammonia-hydrogen engine is adjusted to the corresponding operating condition to improve the thermal efficiency of the ammonia-hydrogen engine.

[0017] The present invention provides an ammonia-hydrogen engine and a combustion system thereof, which adopt the control method of the ammonia-hydrogen engine of the present invention, and therefore have the same advantages as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 This is one of the flow charts of the control method of the ammonia hydrogen engine provided by the present invention.

[0020] Figure 2 This is one of the flow charts of the control method of the ammonia hydrogen engine provided by the present invention.

[0021] Figure 3 It is a structural schematic diagram of the ammonia hydrogen engine provided by the present invention.

[0022] Figure 4 It is a structural schematic diagram of the ammonia hydrogen engine provided by the present invention.

[0023] Reference numerals: 1. Ammonia storage tank; 2. Ammonia pipeline; 3. Ammonia pressure reducing valve; 4. Ammonia booster pump; 5. Hydrogen storage tank; 6. Hydrogen pressure reducing valve; 7. Hydrogen pipeline; 8. Hydrogen injector; 9. Ammonia injector; 10. Intake duct; 11. Spark plug; 12. Combustion chamber; 13. Engine cylinder head; 14. Exhaust duct. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In the description of the present embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present embodiment and simplifying the description, and do not indicate or imply that the referred device or element 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 embodiment.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this embodiment, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] In this embodiment, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this embodiment can be understood according to specific circumstances.

[0028] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0029] Combine the following Figure 1 and Figure 2 A control method of an ammonia-hydrogen engine of the present invention is described. The control method is optimized for the control method when the ammonia-hydrogen engine is in a starting condition and in an operating condition. The ammonia-hydrogen engine provided by the present invention includes: an ammonia pressure reducing valve 3, an ammonia booster pump 4, a hydrogen pressure reducing valve 6, a hydrogen injector 8, an ammonia injector 9, an intake duct 10, a spark plug 11, a combustion chamber 12, an engine cylinder head 13, an exhaust duct 14 and a controller. The corresponding combustion system of the ammonia-hydrogen engine is equipped with an ammonia storage tank 1, an ammonia pipeline 2, a hydrogen storage tank 5 and a hydrogen pipeline 7.

[0030] Wherein, when the ammonia hydrogen engine is in the starting condition, the following steps are included: S1, controlling the motor to drive the crankshaft to rotate, using hydrogen as fuel, so that a hydrogen and air mixture environment is formed in the combustion chamber 12, and the ammonia hydrogen engine is in idling operation; S2. After the ammonia-hydrogen engine is successfully started, the motor is disconnected, and ammonia and hydrogen are used as fuel, so that a mixture of hydrogen, ammonia and air is formed in the combustion chamber 12, and the ammonia-hydrogen engine stops idling; When the ammonia hydrogen engine is in operation, the following steps are included: S3. Obtain a first temperature of a coolant and / or a second temperature of a lubricating oil used by the ammonia-hydrogen engine, and adjust the ammonia-hydrogen engine to a corresponding operating condition according to the first temperature and / or the second temperature.

[0031] It should be understood that the above control method is implemented by a controller equipped with the ammonia-hydrogen engine. The above control method can be made into software and stored in the controller to control the working state of the ammonia-hydrogen engine.

[0032] Specifically, when the ammonia-hydrogen engine is in the starting condition, the ammonia-hydrogen engine first uses pure hydrogen as fuel, and uses the characteristic that hydrogen is easy to ignite to achieve rapid starting of the ammonia-hydrogen engine. At this stage, the controller controls the hydrogen pressure reducing valve 6 to a suitable pressure, and the controller controls the hydrogen injector 8 to spray gaseous hydrogen into the intake duct 10 during the intake stroke. The hydrogen and air are initially mixed in the intake duct 10 and then enter the combustion chamber 12. The piston movement drives the air flow movement in the combustion chamber 12, and promotes further mixing of hydrogen and air in the combustion chamber 12, forming a hydrogen / air mixture that is easy to burn in the combustion chamber 12, so that the engine is in a low-load condition that can be stably operated, and successfully starts and enters idle operation. At this stage, the advantages of hydrogen such as low minimum ignition energy, fast combustion speed, high lean burn limit, and short flame quenching distance can be fully utilized. Even in the cold state of the engine, rapid starting can be achieved, and the lean burn strategy can be used to achieve low-load, non-knock operation of pure hydrogen, avoiding the problem of difficult cold starting of the ammonia engine.

[0033] When the ammonia-hydrogen engine is successfully started and is idling, the motor is disconnected, and the ammonia-hydrogen engine uses ammonia + hydrogen as fuel instead. By using ammonia fuel to replace part or all of the hydrogen fuel, the low-cost ammonia fuel can be used to reduce the cost of engine use. At this stage, the controller controls the ammonia pressure reducing valve 3, the ammonia booster pump 4, and the hydrogen pressure reducing valve 6 to adjust to the appropriate pressure according to the injection pressure requirement, and increases the speed of the ammonia-hydrogen engine. At this stage, ammonia + hydrogen is used as fuel, and a high compression ratio and medium-to-high load operation strategy is adopted to promote the combustion of ammonia by utilizing the high temperature in the cylinder at the compression top dead center. At the same time, hydrogen premixing and spark ignition are used to ignite the ammonia fuel to achieve an ignition-compression ignition efficient combustion organization mode, which is beneficial to improving the combustion effect of low-activity ammonia. At the same time, the strong anti-knock ability of ammonia is utilized to achieve stable and knock-free operation of the engine under high compression ratio and high load conditions.

[0034] It can be seen that the present invention first uses easily combustible hydrogen as fuel when the ammonia-hydrogen engine is in the starting state, so that the hydrogen fuel and the air form a mixed gas, thereby facilitating the ammonia-hydrogen engine to start quickly and run at idle speed; thereafter, the concentration of ammonia fuel is increased to replace part or all of the hydrogen fuel, and the speed of the ammonia-hydrogen engine is increased to adjust to a suitable operating condition. Since the cost of ammonia fuel is much lower than that of hydrogen fuel, the use cost of the ammonia-hydrogen engine is reduced.

[0035] When the ammonia-hydrogen engine is in operation, the speed, load, and fuel composition are adjusted according to the current power demand of the hybrid system, so that the engine operates in a high thermal efficiency range, and the operating conditions are dynamically adjusted according to the engine status, specifically: the water temperature of the coolant used by the current ammonia-hydrogen engine and the oil temperature of the lubricating oil used are read once every 30 seconds, and the target operating range of the highest thermal efficiency allowed under the current temperature conditions of the ammonia-hydrogen engine is updated based on the system preset parameters according to the current power demand of the hybrid system, and the engine is switched to the target operating range for operation. At this stage, ammonia is used as the main fuel, and the energy proportion of ammonia in the fuel is increased as much as possible under the condition of meeting the stable operation of the ammonia-hydrogen engine, and even pure ammonia is used as fuel, which can make full use of the advantages of ammonia being easy to liquefy and having low storage and transportation costs, reduce the fuel consumption cost of the engine, and make full use of the advantages of liquid ammonia having high volume energy density. By storing liquid ammonia fuel, the vehicle's cruising range is extended, avoiding the shortcomings of hydrogen engine vehicles with high use costs and short cruising range.

[0036] In order to switch to a new target operating range, the controller controls the ammonia pressure reducing valve 3, the ammonia boost pump 4, the hydrogen pressure reducing valve 6, the ammonia injector 9, the ammonia injector 9, and the spark plug 11 to a suitable working state, thereby adjusting the speed, load, and fuel composition of the ammonia-hydrogen engine.

[0037] It can be seen that the control method of an ammonia-hydrogen engine provided by the present invention is optimized for the control method when the ammonia-hydrogen engine is in a starting condition and in an operating condition. When the ammonia-hydrogen engine is in a starting condition, the control motor drives the crankshaft to rotate, and hydrogen is used as fuel, so that a hydrogen and air mixed gas environment is formed in the combustion chamber 12, and the ammonia-hydrogen engine is in an idling operation, thereby facilitating the rapid start of the ammonia-hydrogen engine; after the ammonia-hydrogen engine is successfully started, the motor is disconnected, and ammonia and hydrogen are used as fuels, so that a hydrogen, ammonia and air mixed gas environment is formed in the combustion chamber 12, and the ammonia-hydrogen engine is out of idling operation, thereby reducing the use cost of the ammonia-hydrogen engine. When the ammonia-hydrogen engine is in an operating condition, the first temperature of the coolant used by the ammonia-hydrogen engine and / or the second temperature of the lubricating oil are obtained, and according to the first temperature and / or the second temperature, the ammonia-hydrogen engine is adjusted to the corresponding operating condition to improve the thermal efficiency of the ammonia-hydrogen engine.

[0038] In one embodiment of the present invention, when the ammonia hydrogen engine is in an operating condition, after obtaining the first temperature of the coolant used by the ammonia hydrogen engine and / or the second temperature of the lubricating oil, and adjusting the ammonia hydrogen engine to a corresponding operating condition according to the first temperature and / or the second temperature, that is, after step S3, it also includes: S4, obtaining the current cycle fluctuation rate of the ammonia hydrogen engine, and adjusting the operating condition of the ammonia hydrogen engine according to the current cycle fluctuation rate of the ammonia hydrogen engine. Since the switch to the corresponding operating condition in step S3 is the operating condition that needs to be adjusted obtained by experience summary or table lookup, therefore, step S4 further adjusts the operating condition of the engine according to the current cycle fluctuation rate of the ammonia hydrogen engine, thereby improving the operating efficiency of the ammonia hydrogen engine. In one of the embodiments of the present invention, the current cycle volatility of the ammonia-hydrogen engine is obtained, and the operating condition of the ammonia-hydrogen engine is adjusted according to the current cycle volatility of the ammonia-hydrogen engine, that is, step S4 specifically includes: S41, presetting the maximum cycle volatility value and the minimum cycle volatility value; S42, if the current cycle volatility of the ammonia-hydrogen engine is between the preset maximum cycle volatility value and the preset minimum cycle volatility value, maintaining the current operating condition of the ammonia-hydrogen engine; if the current cycle volatility of the ammonia-hydrogen engine is greater than the preset maximum cycle volatility value, increasing the energy proportion of hydrogen in the fuel; if the current cycle volatility of the ammonia-hydrogen engine is less than the preset minimum cycle volatility value, reducing the energy proportion of hydrogen in the fuel.

[0039] In the above-mentioned embodiment, by presetting a maximum cycle fluctuation rate (hereinafter referred to as "maximum value") and a minimum cycle fluctuation rate (hereinafter referred to as "minimum value"), the operating condition of the ammonia-hydrogen engine is adjusted according to whether the current cycle fluctuation rate of the ammonia-hydrogen engine is between the maximum value and the minimum value.

[0040] If the current cycle fluctuation rate is between the maximum and minimum values, it is considered that the current ammonia hydrogen engine operating conditions are appropriate and no adjustment is required.

[0041] If the current cycle fluctuation rate is greater than the maximum value, it means that the combustion system control strategy cannot form sufficient combustion in the combustion chamber 12 at this time. In order to make the engine run more stably, the energy proportion of hydrogen in the fuel should be increased, and the advantages of low ignition energy and fast combustion speed of hydrogen should be used to strengthen the combustion in the combustion chamber 12. Therefore, the controller controls the hydrogen injector 8 to increase the injection pulse width to increase the hydrogen fuel supply flow rate, and the controller controls the ammonia injector 9 to reduce the injection pulse width to reduce the ammonia fuel supply flow rate, thereby increasing the energy proportion of hydrogen in the fuel until 100% (the engine uses pure hydrogen as fuel at this time).

[0042] If the current cycle fluctuation rate is less than the minimum value, it means that the control strategy of the combustion system can form a very sufficient combustion in the combustion chamber 12 at this time, and the hydrogen combustion-supporting effect is redundant. In order to reduce the consumption of high-cost hydrogen fuel, the energy proportion of hydrogen in the fuel should be reduced under the condition of stable engine operation, and the advantages of ammonia being easy to liquefy and having low storage and transportation costs should be used to reduce the engine use cost. Therefore, the controller controls the hydrogen injector 8 to reduce the injection pulse width to reduce the hydrogen fuel supply flow rate, and the controller controls the ammonia injector 9 to increase the injection pulse width to increase the ammonia fuel supply flow rate, thereby reducing the energy proportion of hydrogen in the fuel until it reaches 0% (at this time, the engine uses pure ammonia as fuel).

[0043] In one embodiment of the present invention, if the current cycle fluctuation rate of the ammonia-hydrogen engine is greater than the preset maximum cycle fluctuation rate, the energy ratio of hydrogen in the fuel is increased to 100%. If the cycle fluctuation rate of the ammonia-hydrogen engine is still greater than the preset maximum cycle fluctuation rate, the operating power and / or speed of the ammonia-hydrogen engine is reduced until the cycle fluctuation rate is less than the preset maximum cycle fluctuation rate. In this embodiment, when the problem of large cycle fluctuation rate still exists when pure hydrogen is used as fuel, the ammonia pressure reducing valve 3, the ammonia booster pump 4, the hydrogen pressure reducing valve 6, the ammonia injector 9, the hydrogen injector 8 and the spark plug 11 are controlled to a new working state, so as to reduce the engine speed and operating power, increase the engine load, and make the engine enter a working point where it is easier to operate stably until the cycle fluctuation rate is less than the maximum value.

[0044] In one embodiment of the present invention, when the ammonia-hydrogen engine is in the starting condition, that is, steps S1 and S2 specifically include: determining that the excess air coefficient of the ammonia-hydrogen engine is 1.0-2.5, and when the ammonia-hydrogen engine indicates that the mean effective pressure is less than 0.6MPa, determining that the ammonia-hydrogen engine is in the idle operation of the small load condition, and when the ammonia-hydrogen engine indicates that the mean effective pressure is greater than 0.9MPa and less than 1.2MPa, determining that the ammonia-hydrogen engine is in the medium-to-high load condition and is out of the idle operation. In step S1, when the ammonia-hydrogen engine indicates that the mean effective pressure is less than 0.6MPa, it is determined that the ammonia-hydrogen engine is in the idle operation, that is, the ammonia-hydrogen engine uses hydrogen as fuel, and a hydrogen and air mixed gas environment is formed in the combustion chamber 12; in step S2, when the ammonia-hydrogen engine indicates that the mean effective pressure is greater than 0.9MPa and less than 1.2MPa, it is determined that the ammonia-hydrogen engine is in the medium-to-high load condition out of the idle operation, that is, the motor is disconnected, ammonia and hydrogen are used as fuel, and a hydrogen, ammonia and air mixed gas environment is formed in the combustion chamber 12.

[0045] In one embodiment of the present invention, the preset maximum value of the cyclic volatility is in the range of 4% to 6%, and the preset minimum value of the cyclic volatility is in the range of 0.5% to 2%.

[0046] like Figure 3As shown, the present invention also provides an ammonia hydrogen engine. The ammonia hydrogen engine includes: a combustion chamber 12, an intake duct 10, an exhaust duct 14, a spark plug 11, an ammonia pressure reducing valve 3, an ammonia booster pump 4, a hydrogen pressure reducing valve 6, an ammonia injector 9, a hydrogen injector 8 and a controller. The intake duct 10 and the exhaust duct 14 are respectively connected to the combustion chamber 12, the ammonia injector 9 and the hydrogen injector 8 are both connected to the same intake duct 10, the spark plug 11 extends to the combustion chamber 12, the ammonia pressure reducing valve 3 and the ammonia booster pump 4 are connected in parallel between the ammonia storage tank 1 and the ammonia injector 9, and the hydrogen pressure reducing valve 6 is connected between the hydrogen storage tank 5 and the hydrogen injector 8. The controller executes the control method of the ammonia hydrogen engine provided in the above embodiment of the present invention, and is electrically connected to the ammonia pressure reducing valve 3, the ammonia booster pump 4, the hydrogen pressure reducing valve 6, the ammonia injector 9, the hydrogen injector 8 and the spark plug 11.

[0047] For the ammonia-hydrogen engine of this embodiment, the specific control process of step S2 is as follows: The controller controls the hydrogen injector 8 and the ammonia injector 9 to inject hydrogen and ammonia fuels respectively into the intake duct 10 during the intake stroke. The hydrogen and ammonia fuels are preliminarily mixed with the air in the intake duct 10 and then enter the combustion chamber 12. The piston movement drives the airflow movement in the combustion chamber 12 and promotes further mixing of the hydrogen, ammonia fuel and air in the combustion chamber 12, forming an ammonia / hydrogen / air mixture with a higher energy density in the combustion chamber 12, so that the engine is in a medium to high load condition where it can operate efficiently, and enters normal operation after leaving idle operation.

[0048] Specifically, the present invention provides an ammonia-hydrogen engine, in which an ammonia injector 9 and a hydrogen injector 8 are arranged in the same intake duct 10; holes are reserved on the engine cylinder head 13 for installing the intake duct 10, the spark plug 11 and the exhaust duct 14.

[0049] The opening for installing the intake duct 10 or the exhaust duct 14 is optionally arranged on the top surface or the side of the engine cylinder head 13, the combustion chamber 12 is respectively connected with the intake duct 10 and the exhaust duct 14, the opening for installing the spark plug 11 is arranged on the top surface of the engine cylinder head 13, the spark plug 11 is installed at the geometric center of the combustion chamber 12, and the ignition electrode of the spark plug 11 is arranged in the combustion chamber 12. Holes are reserved on the intake duct 10 for installing the hydrogen injector 8 and the ammonia injector 9.

[0050] Ammonia fuel is stored in an ammonia storage tank 1, which is provided with an outlet and connected to the inlets of an ammonia pressure reducing valve 3 and an ammonia booster pump 4 through an ammonia pipeline 2. The outlets of the ammonia pressure reducing valve 3 and the ammonia booster pump 4 are connected to an ammonia injector 9 through the ammonia pipeline 2. The outlet of the ammonia injector 9 is provided in an intake duct 10. In actual use, the ammonia fuel is in a gas phase or a liquid phase. The ammonia in the ammonia storage tank 1 is reduced in pressure by the ammonia pressure reducing valve 3 or pressurized by the ammonia booster pump 4, and is injected into the intake duct 10 through the ammonia injector 9.

[0051] Among them, the axial angle between the hydrogen injector 8 and the ammonia injector 9 can be optionally parallel or non-parallel, the relationship between the hydrogen injector 8 and the ammonia injector 9 and the surface of the intake duct 10 can be optionally vertical or non-vertical, and the hydrogen injector 8 or the ammonia injector 9 can be optionally arranged on the side closer to the combustion chamber 12.

[0052] The hydrogen injector 8 and the ammonia injector 9 may be arranged in the intake duct 10 in any manner that can achieve fixed connection, and the embodiment of the present invention does not impose any limitation on this. For example, the hydrogen injector 8 and the ammonia injector 9 are fixedly installed in the intake duct 10 by screws.

[0053] The compression ratio of the ammonia hydrogen engine is 20~25; the injection pressure of the ammonia injector 9 is 0.4~30MPa.

[0054] like Figure 4 As shown, the present invention also provides an ammonia hydrogen engine. The ammonia hydrogen engine includes: a combustion chamber 12, an intake duct 10, an exhaust duct 14, a spark plug 11, an ammonia pressure reducing valve 3, an ammonia booster pump 4, a hydrogen pressure reducing valve 6, an ammonia injector 9, a hydrogen injector 8 and a controller. The intake duct 10 and the exhaust duct 14 are respectively connected to the combustion chamber 12, the ammonia injector 9 and the hydrogen injector 8 are respectively connected to different intake ducts 10, the spark plug 11 extends to the combustion chamber 12, the ammonia pressure reducing valve 3 and the ammonia booster pump 4 are connected in parallel between the ammonia storage tank 1 and the ammonia injector 9, and the hydrogen pressure reducing valve 6 is connected between the hydrogen storage tank 5 and the hydrogen injector 8. The controller executes the control method of the ammonia hydrogen engine provided in the above embodiment of the present invention, and is electrically connected to the ammonia pressure reducing valve 3, the ammonia booster pump 4, the hydrogen pressure reducing valve 6, the ammonia injector 9, the hydrogen injector 8 and the spark plug 11.

[0055] For the ammonia-hydrogen engine of this embodiment, the specific control process of step S2 is as follows: The controller controls the hydrogen injector 8 to inject hydrogen fuel into the intake duct 10 during the intake stroke. The hydrogen fuel and air are preliminarily mixed in the intake duct 10 and then enter the combustion chamber 12. The controller controls the ammonia injector 9 to inject ammonia fuel into the combustion chamber 12 during the intake stroke or the early stage of the compression stroke. The piston movement drives the air flow movement in the combustion chamber 12 and promotes further mixing of hydrogen, ammonia fuel and air in the combustion chamber 12, forming an ammonia / hydrogen / air mixture with higher energy density in the combustion chamber 12, so that the engine is in a medium to high load condition where it can operate efficiently, and enters normal operation after leaving idle operation.

[0056] Specifically, the present invention provides an ammonia-hydrogen engine, in which an ammonia injector 9 is arranged in an engine cylinder head 13; holes are reserved on the engine cylinder head 13 for installing the ammonia injector 9, an intake duct 10, a spark plug 11 and an exhaust duct 14.

[0057] Among them, the opening for installing the ammonia injector 9 is set on the top surface of the engine cylinder head 13, the opening for installing the intake duct 10 or the exhaust duct 14 is optionally set on the top surface or side of the engine cylinder head 13, the combustion chamber 12 is connected with the intake duct 10 and the exhaust duct 14 respectively, the opening for installing the spark plug 11 is set on the top surface of the engine cylinder head 13, the spark plug 11 is installed at the geometric center of the combustion chamber 12, and the ignition electrode of the spark plug 11 is set in the combustion chamber 12. A hole is reserved on the intake duct 10 for installing the hydrogen injector 8.

[0058] Among them, ammonia fuel is stored in an ammonia storage tank 1, and the ammonia storage tank 1 is provided with an outlet, and is connected to the inlet of the ammonia pressure reducing valve 3 and the ammonia booster pump 4 through an ammonia pipeline 2. The outlets of the ammonia pressure reducing valve 3 and the ammonia booster pump 4 are connected to the ammonia injector 9 through the ammonia pipeline 2, and the outlet of the ammonia injector 9 is arranged in the combustion chamber 12. In actual use, the ammonia fuel is in gas phase or liquid phase, and the ammonia in the ammonia storage tank 1 is reduced in pressure by the ammonia pressure reducing valve 3 or pressurized by the ammonia booster pump 4, and injected into the combustion chamber 12 through the ammonia injector 9.

[0059] Among them, the positional relationship between the hydrogen injector 8 and the intake duct 10 can be optionally vertical or non-vertical, the axial angle between the ammonia injector 9 and the spark plug 11 can be optionally parallel or non-parallel, the relationship between the ammonia injector 9 and the surface of the engine cylinder head 13 can be optionally vertical or non-vertical, and the ammonia injector 9 can be optionally arranged on the side closer to the intake duct 10 or the exhaust duct 14.

[0060] Among them, the way in which the hydrogen injector 8 is arranged in the intake duct 10 and the way in which the ammonia injector 9 is arranged in the engine cylinder head 13 can be any way that can achieve fixed connection, and the embodiment of the present invention does not impose any limitation on this. For example: the hydrogen injector 8 is fixedly installed in the intake duct 10 by screws, and the ammonia injector 9 is fixedly installed in the engine cylinder head 13 by screws.

[0061] The compression ratio of the ammonia hydrogen engine is 20~25; the injection pressure of the ammonia injector 9 is 0.4~30MPa.

[0062] for Figure 3 and Figure 4 There are two forms of ammonia hydrogen engines: Hydrogen fuel is stored in the hydrogen storage tank 5. An outlet is provided on the top of the hydrogen storage tank 5 and is connected to the inlet of the hydrogen pressure reducing valve 6 through the hydrogen pipeline 7. The outlet of the hydrogen pressure reducing valve 6 is connected to the hydrogen injector 8 through the hydrogen pipeline 7. The outlet of the hydrogen injector 8 is provided in the intake duct 10. In actual use, the hydrogen fuel is in gas phase. After the hydrogen in the hydrogen storage tank 5 is reduced in pressure by the hydrogen pressure reducing valve 6, it is injected into the intake duct 10 through the hydrogen injector 8.

[0063] The top / bottom of the ammonia storage tank 1 and the hydrogen storage tank 5 is only a relative area, and the embodiment of the present invention does not impose any limitation on the specific position of the opening.

[0064] The ammonia pressure reducing valve 3, the ammonia booster pump 4, the hydrogen pressure reducing valve 6, the ammonia injector 9, the ammonia injector 9, and the spark plug 11 are all electrically connected to the controller.

[0065] Optionally, the ammonia pipeline 2 and the hydrogen pipeline 7 are both stainless steel pipes.

[0066] Optionally, the engine compression ratio of the ammonia hydrogen engine combustion system is 20~25.

[0067] Optionally, the intake stroke is a crankshaft angle of 180 to 360 degrees before compression top dead center.

[0068] Optionally, the early stage of the compression stroke is a crankshaft angle of 90 to 180 degrees before the compression top dead center.

[0069] In the embodiment of the present invention, the ammonia fuel can be injected in the low-cost ammonia inlet 10 mode (i.e. Figure 3 The ammonia-hydrogen engine shown in the figure) can also adopt a high power density ammonia direct injection mode (i.e. Figure 4 The ammonia-hydrogen engine shown in the figure) requires less modification to the engine structure and is easy to put into use quickly, while the latter can achieve a larger engine filling coefficient and power density, which is conducive to further expanding the engine performance boundaries.

[0070] The present invention also provides a combustion system of an ammonia-hydrogen engine, which comprises: an ammonia storage tank 1, an ammonia pipeline 2, a hydrogen storage tank 5, a hydrogen pipeline 7, and the ammonia-hydrogen engine in the above embodiment of the present invention. The ammonia storage tank 1 is connected to the ammonia injector 9 through the ammonia pipeline 2, and the hydrogen storage tank 5 is connected to the hydrogen injector 8 through the hydrogen pipeline 7.

[0071] From the above description, it can be seen that the embodiment of the present invention uses pure hydrogen as fuel during the engine startup phase, which can fully utilize the advantages of hydrogen such as low minimum ignition energy, fast combustion speed, high lean burn limit, and short flame quenching distance. Even when the engine is in a cold state, rapid startup can be achieved, and the lean burn strategy can be used to achieve low-load, knock-free operation of pure hydrogen, thus avoiding the problem of difficult cold start of ammonia engines.

[0072] In the embodiment of the present invention, the engine uses ammonia + hydrogen as fuel during the normal operation stage, adopts a high compression ratio and medium-to-high load operation strategy to promote the combustion of ammonia by utilizing the high temperature in the cylinder at the compression top dead center, and simultaneously uses hydrogen premixing and spark ignition to ignite the ammonia fuel to achieve an ignition-compression ignition efficient combustion organization mode, which is beneficial to improving the combustion effect of low-activity ammonia. At the same time, the strong anti-knock ability of ammonia is utilized to achieve stable and knock-free operation of the engine under high compression ratio and high load conditions.

[0073] In the embodiment of the present invention, the engine uses ammonia as the main fuel during the normal operation stage. The energy proportion of ammonia in the fuel is increased as much as possible while ensuring the stable operation of the engine. Even pure ammonia is used as the fuel. The advantages of ammonia being easy to liquefy and having low storage and transportation costs can be fully utilized to reduce the engine fuel consumption cost. The advantages of liquid ammonia having a high volume energy density can be fully utilized. The vehicle's cruising range can be extended by storing liquid ammonia fuel, thereby avoiding the disadvantages of hydrogen engine vehicles having high operating costs and short cruising range.

[0074] In the embodiment of the present invention, ammonia fuel can adopt a low-cost ammonia intake duct 10 injection mode, or a high-power density ammonia direct injection mode. The former requires less modification to the engine structure and is convenient for rapid commissioning, while the latter can achieve a larger engine filling coefficient and power density, which is conducive to further expanding the engine performance boundary.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for an ammonia hydrogen engine, characterized in that: include: When the ammonia hydrogen engine is in the starting condition, it includes: S1, controlling the motor to drive the crankshaft to rotate, using hydrogen as fuel, so that a hydrogen and air mixed gas environment is formed in the combustion chamber (12), and the ammonia hydrogen engine is in idle operation; S2. After the ammonia-hydrogen engine is successfully started, the motor is disconnected, and ammonia and hydrogen are used as fuel, so that a mixture of hydrogen, ammonia and air is formed in the combustion chamber (12), and the ammonia-hydrogen engine stops idling; When the ammonia hydrogen engine is in operation, it includes: S3. Obtain a first temperature of a coolant and / or a second temperature of a lubricating oil used by the ammonia-hydrogen engine, and adjust the ammonia-hydrogen engine to a corresponding operating condition according to the first temperature and / or the second temperature.

2. The control method of the ammonia hydrogen engine according to claim 1, characterized in that: When the ammonia-hydrogen engine is in an operating condition, and after the step of obtaining the first temperature of the coolant used by the ammonia-hydrogen engine and / or the second temperature of the lubricating oil, and adjusting the ammonia-hydrogen engine to a corresponding operating condition according to the first temperature and / or the second temperature, the method further includes: S4. Obtain the current cycle fluctuation rate of the ammonia-hydrogen engine, and adjust the operating condition of the ammonia-hydrogen engine according to the current cycle fluctuation rate of the ammonia-hydrogen engine.

3. The control method of the ammonia hydrogen engine according to claim 2, characterized in that: The obtaining of the current cycle fluctuation rate of the ammonia-hydrogen engine and adjusting the operating condition of the ammonia-hydrogen engine according to the current cycle fluctuation rate of the ammonia-hydrogen engine specifically includes: S41, presetting a maximum value of the cyclic volatility and a minimum value of the cyclic volatility; S42, if the current cycle fluctuation rate of the ammonia-hydrogen engine is between the preset cycle fluctuation rate maximum value and the cycle fluctuation rate minimum value, then maintaining the current operating condition of the ammonia-hydrogen engine; If the current cycle fluctuation rate of the ammonia hydrogen engine is greater than the preset maximum cycle fluctuation rate, the energy proportion of hydrogen in the fuel is increased; If the current cycle fluctuation rate of the ammonia hydrogen engine is less than the preset minimum cycle fluctuation rate, the energy proportion of hydrogen in the fuel is reduced.

4. The control method of the ammonia hydrogen engine according to claim 3, characterized in that: If the current cycle fluctuation rate of the ammonia-hydrogen engine is greater than the preset maximum cycle fluctuation rate, the energy proportion of hydrogen in the fuel is increased to 100%. If the cycle fluctuation rate of the ammonia-hydrogen engine is still greater than the preset maximum cycle fluctuation rate, the operating power and / or speed of the ammonia-hydrogen engine is reduced until the cycle fluctuation rate is less than the preset maximum cycle fluctuation rate.

5. The control method of an ammonia-hydrogen engine according to claim 1, characterized in that: When the ammonia hydrogen engine is in the starting condition, it specifically includes: Determine that the excess air coefficient of the ammonia-hydrogen engine is 1.0~2.5, and when the ammonia-hydrogen engine indicates a mean effective pressure of less than 0.6MPa, determine that the ammonia-hydrogen engine is idling under a low load condition; when the ammonia-hydrogen engine indicates a mean effective pressure greater than 0.9MPa and less than 1.2MPa, determine that the ammonia-hydrogen engine is in a medium-to-high load condition and is out of idling.

6. The control method of an ammonia-hydrogen engine according to claim 3 or 4, characterized in that: The preset maximum cyclic volatility ranges from 4% to 6%, and the preset minimum cyclic volatility ranges from 0.5% to 2%.

7. An ammonia hydrogen engine, characterized in that: include: A combustion chamber (12), an intake passage (10), an exhaust passage (14), a spark plug (11), an ammonia pressure reducing valve (3), an ammonia booster pump (4), a hydrogen pressure reducing valve (6), an ammonia injector (9), a hydrogen injector (8), and a controller; The intake passage (10) and the exhaust passage (14) are respectively connected to the combustion chamber (12); the ammonia injector (9) and the hydrogen injector (8) both lead to the same intake passage (10); the spark plug (11) extends to the combustion chamber (12); the ammonia pressure reducing valve (3) and the ammonia booster pump (4) are connected in parallel between the ammonia storage tank (1) and the ammonia injector (9); and the hydrogen pressure reducing valve (6) is connected between the hydrogen storage tank (5) and the hydrogen injector (8); The controller executes the control method of the ammonia-hydrogen engine according to any one of claims 1 to 6, and is electrically connected to the ammonia pressure reducing valve (3), the ammonia booster pump (4), the hydrogen pressure reducing valve (6), the ammonia injector (9), the hydrogen injector (8) and the spark plug (11).

8. The ammonia-hydrogen engine according to claim 7, characterized in that: The compression ratio of the ammonia-hydrogen engine is 20-25; the injection pressure of the ammonia injector (9) is 0.4-30 MPa.

9. An ammonia hydrogen engine, characterized in that: include: A combustion chamber (12), an intake passage (10), an exhaust passage (14), a spark plug (11), an ammonia pressure reducing valve (3), an ammonia booster pump (4), a hydrogen pressure reducing valve (6), an ammonia injector (9), a hydrogen injector (8), and a controller; The intake passage (10) and the exhaust passage (14) are respectively connected to the combustion chamber (12); the ammonia injector (9) and the hydrogen injector (8) are respectively connected to different intake passages (10); the spark plug (11) extends to the combustion chamber (12); the ammonia pressure reducing valve (3) and the ammonia booster pump (4) are connected in parallel between the ammonia storage tank (1) and the ammonia injector (9); and the hydrogen pressure reducing valve (6) is connected between the hydrogen storage tank (5) and the hydrogen injector (8); The controller executes the control method of the ammonia-hydrogen engine according to any one of claims 1 to 6, and is electrically connected to the ammonia pressure reducing valve (3), the ammonia booster pump (4), the hydrogen pressure reducing valve (6), the ammonia injector (9), the hydrogen injector (8) and the spark plug (11).

10. The ammonia-hydrogen engine according to claim 9, characterized in that: The compression ratio of the ammonia-hydrogen engine is 20-25; the injection pressure of the ammonia injector (9) is 0.4-30 MPa.

11. A combustion system of an ammonia hydrogen engine, characterized in that: include: An ammonia storage tank (1), an ammonia pipeline (2), a hydrogen storage tank (5), a hydrogen pipeline (7), and an ammonia-hydrogen engine as claimed in any one of claims 7 to 10; The ammonia storage tank (1) is connected to the ammonia injector (9) via the ammonia pipeline (2), and the hydrogen storage tank (5) is connected to the hydrogen injector (8) via the hydrogen pipeline (7).

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