Control method for ammonia-hydrogen engine, ammonia-hydrogen engine and combustion system thereof

Abstract

The present application relates to the technical field of new energy engine, and particularly relates to a control method of ammonia-hydrogen engine, the ammonia-hydrogen engine and a combustion system thereof. The control method is optimized for engine starting conditions and running conditions. When the engine is in the starting condition, the motor drives the crankshaft to rotate, hydrogen is used as fuel, a hydrogen and air mixture environment is formed in the combustion chamber, the ammonia-hydrogen engine is in idle operation, and thus the ammonia-hydrogen engine is easy to start quickly. After the engine starts successfully, the motor is disconnected, ammonia and hydrogen are used as fuel, a hydrogen, ammonia and air mixture environment is formed in the combustion chamber, the ammonia-hydrogen engine is separated from the idle operation, and thus the use cost of the ammonia-hydrogen engine is reduced. When the engine is in the running condition, the first temperature of the coolant and / or the second temperature of the lubricating oil used by the ammonia-hydrogen engine are obtained, and according to the first temperature and / or the second temperature, the ammonia-hydrogen engine is adjusted to the corresponding condition, and the thermal efficiency of the ammonia-hydrogen engine is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy engines, and particularly relates to a control method of an ammonia-hydrogen engine, the ammonia-hydrogen engine and a combustion system thereof. BACKGROUND

[0002] In recent years, internal combustion engines using ammonia fuel and hydrogen fuel have attracted extensive attention from the industry and academia. Existing research shows that stable operation of the ammonia-hydrogen engine can be achieved by using a small amount of hydrogen (energy ratio less than 3%). Considering that the cost of ammonia is lower than that of hydrogen, a lower hydrogen energy ratio in ammonia-hydrogen fuel helps to reduce the overall cost of fuel and is conducive to technology popularization. It should be pointed out that ammonia is low in activity and difficult to burn, and is difficult to be used in cold start or small load conditions. Hydrogen is extremely active and prone to early combustion, which poses a challenge to the high-efficiency and stable operation of the engine under heavy load conditions. However, ammonia has strong anti-knock performance, which is conducive to realizing knock-free combustion of the engine under heavy load conditions. Hydrogen has low minimum ignition energy and short flame quenching distance, which can realize stable operation of the engine under small load conditions.

[0003] For the ammonia-hydrogen engine, since ammonia fuel is not suitable for starting conditions, hydrogen fuel is not suitable for heavy load conditions, and the cost of hydrogen fuel is high, how to adjust the combustion strategy of the ammonia-hydrogen engine to improve the combustion efficiency and reduce the cost is a problem to be solved. SUMMARY

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

[0005] The present application provides a control method of an ammonia-hydrogen engine, comprising:

[0006] When the ammonia-hydrogen engine is in a starting condition, comprising:

[0007] S1, controlling the motor to drive the crankshaft to rotate, using hydrogen as fuel to form a hydrogen and air mixture environment in the combustion chamber, and the ammonia-hydrogen engine is in idle operation;

[0008] S2, after the ammonia-hydrogen engine is successfully started, the motor is disconnected, and ammonia and hydrogen are used as fuel to form a hydrogen, ammonia and air mixture environment in the combustion chamber, and the ammonia-hydrogen engine is separated from the idle operation;

[0009] When the ammonia-hydrogen engine is in a running condition, comprising:

[0010] S3, obtaining a first temperature of the cooling liquid and / or a second temperature of the lubricating oil used by the ammonia-hydrogen engine, and adjusting the ammonia-hydrogen engine to a corresponding condition according to the first temperature and / or the second temperature.

[0011] The control method of the ammonia-hydrogen engine according to the present application, when the ammonia-hydrogen engine is in the running mode, further comprises the following steps after the steps of obtaining the first temperature of the cooling liquid and / or the second temperature of the lubricating oil used by the ammonia-hydrogen engine, and adjusting the ammonia-hydrogen engine to the corresponding mode according to the first temperature and / or the second temperature:

[0012] S4, obtaining the current cycle fluctuation rate of the ammonia-hydrogen engine, and adjusting the running mode of the ammonia-hydrogen engine according to the current cycle fluctuation rate of the ammonia-hydrogen engine.

[0013] The control method of the ammonia-hydrogen engine according to the present application, the step of obtaining the current cycle fluctuation rate of the ammonia-hydrogen engine and adjusting the running mode of the ammonia-hydrogen engine according to the current cycle fluctuation rate of the ammonia-hydrogen engine specifically comprises:

[0014] S41, presetting a maximum cycle fluctuation rate and a minimum cycle fluctuation rate;

[0015] S42, if the current cycle fluctuation rate of the ammonia-hydrogen engine is between the preset maximum cycle fluctuation rate and the preset minimum cycle fluctuation rate, maintaining the current running mode of the ammonia-hydrogen engine;

[0016] If the current cycle fluctuation rate of the ammonia-hydrogen engine is greater than the preset maximum cycle fluctuation rate, increasing the energy proportion of hydrogen in the fuel;

[0017] If the current cycle fluctuation rate of the ammonia-hydrogen engine is less than the preset minimum cycle fluctuation rate, reducing the energy proportion of hydrogen in the fuel.

[0018] According to the control method of the ammonia-hydrogen engine according to the present application, 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%, and if the cycle fluctuation rate of the ammonia-hydrogen engine is still greater than the preset maximum cycle fluctuation rate, the running power and / or the rotating speed of the ammonia-hydrogen engine is reduced until the cycle fluctuation rate is less than the preset maximum cycle fluctuation rate.

[0019] The control method of the ammonia-hydrogen engine according to the present application, when the ammonia-hydrogen engine is in the starting mode, specifically comprises:

[0020] Determining that the excess air coefficient of the ammonia-hydrogen engine is 1.0-2.5, and when the indicated mean effective pressure of the ammonia-hydrogen engine is less than 0.6 MPa, determining that the ammonia-hydrogen engine is in the idle operation of the small load mode, and when the indicated mean effective pressure of the ammonia-hydrogen engine is greater than 0.9 MPa and less than 1.2 MPa, determining that the ammonia-hydrogen engine is in the medium-high load mode and is separated from the idle operation.

[0021] According to the control method of the ammonia-hydrogen engine according to the present application, the preset maximum cycle fluctuation rate is in the range of 4%-6%, and the preset minimum cycle fluctuation rate is in the range of 0.5%-2%.

[0022] The application also provides an ammonia-hydrogen engine, comprising a combustion chamber, an air inlet, an air outlet, a spark plug, an ammonia pressure reducing valve, an ammonia pressure increasing pump, a hydrogen pressure reducing valve, an ammonia injector, a hydrogen injector and a controller.

[0023] The air inlet and the air outlet are respectively communicated with the combustion chamber, the ammonia injector and the hydrogen injector are both connected to the same air inlet, the spark plug extends to the combustion chamber, the ammonia pressure reducing valve and the ammonia pressure increasing pump are connected in parallel between an ammonia storage tank and the ammonia injector, and the hydrogen pressure reducing valve is connected between a hydrogen storage tank and the hydrogen injector.

[0024] The controller executes the control method of the ammonia-hydrogen engine and is electrically connected with the ammonia pressure reducing valve, the ammonia pressure increasing pump, the hydrogen pressure reducing valve, the ammonia injector, the hydrogen injector and the spark plug.

[0025] According to the ammonia-hydrogen engine provided by the application, the compression ratio of the ammonia-hydrogen engine is 20-25, and the injection pressure of the ammonia injector is 0.4-30 MPa.

[0026] The application also provides an ammonia-hydrogen engine, comprising a combustion chamber, an air inlet, an air outlet, a spark plug, an ammonia pressure reducing valve, an ammonia pressure increasing pump, a hydrogen pressure reducing valve, an ammonia injector, a hydrogen injector and a controller.

[0027] The air inlet and the air outlet are respectively communicated with the combustion chamber, the ammonia injector and the hydrogen injector are both connected to the same air inlet, the spark plug extends to the combustion chamber, the ammonia pressure reducing valve and the ammonia pressure increasing pump are connected in parallel between an ammonia storage tank and the ammonia injector, and the hydrogen pressure reducing valve is connected between a hydrogen storage tank and the hydrogen injector.

[0028] The controller executes the control method of the ammonia-hydrogen engine and is electrically connected with the ammonia pressure reducing valve, the ammonia pressure increasing pump, the hydrogen pressure reducing valve, the ammonia injector, the hydrogen injector and the spark plug.

[0029] According to the ammonia-hydrogen engine provided by the application, the compression ratio of the ammonia-hydrogen engine is 20-25, and the injection pressure of the ammonia injector is 0.4-30 MPa.

[0030] The application 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.

[0031] The ammonia storage tank is connected with the ammonia injector through the ammonia pipeline, and the hydrogen storage tank is connected with the hydrogen injector through the hydrogen pipeline.

[0032] The application provides a control method of an ammonia-hydrogen engine, which is optimized for the control method when the ammonia-hydrogen engine is in a starting condition and in a running condition. When the ammonia-hydrogen engine is in the starting condition, the motor is controlled to drive the crankshaft to rotate, hydrogen is used as fuel, a hydrogen and air mixed gas environment is formed in the combustion chamber, and the ammonia-hydrogen engine is in idle operation, so that the ammonia-hydrogen engine is easy to start quickly; after the ammonia-hydrogen 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, and the ammonia-hydrogen engine is separated from the idle operation, so that the use cost of the ammonia-hydrogen engine is reduced. When the ammonia-hydrogen engine is in the running condition, the first temperature of the cooling liquid and / or the second temperature of the lubricating oil used by the ammonia-hydrogen engine are obtained, and the ammonia-hydrogen engine is adjusted to the corresponding condition according to the first temperature and / or the second temperature, so that the thermal efficiency of the ammonia-hydrogen engine is improved.

[0033] The ammonia-hydrogen engine and the combustion system thereof provided by the application adopt the control method of the ammonia-hydrogen engine provided by the application, and therefore have the same advantages as above. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0035] Figure 1 is one of the flowcharts of the control method of the ammonia-hydrogen engine provided by the application.

[0036] Figure 2 is one of the flowcharts of the control method of the ammonia-hydrogen engine provided by the application.

[0037] Figure 3 is a structural schematic diagram of the ammonia-hydrogen engine provided by the application.

[0038] Figure 4 is a structural schematic diagram of the ammonia-hydrogen engine provided by the application.

[0039] Reference signs:

[0040] 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, air inlet; 11, spark plug; 12, combustion chamber; 13, engine cylinder head; 14, exhaust passage. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below with reference to the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of the present application.

[0042] In the description of the present embodiment, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present embodiment and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present embodiment.

[0043] In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present embodiment, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0044] In the present embodiment, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection", "fixation" and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrated; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those of ordinary skill in the art, the specific meaning of the above terms in the present embodiment can be understood according to the specific circumstances.

[0045] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be 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 can be "above", "over" and "on" the second feature, which can be that the first feature is directly above or obliquely above the second feature, or only means that the first feature is higher in horizontal height than the second feature. The first feature can be "under", "below" and "underneath" the second feature, which can be that the first feature is directly below or obliquely below the second feature, or only means that the first feature is lower in horizontal height than the second feature.

[0046] The present application will be described below in conjunction with Figure 1 and Figure 2 A control method of an ammonia-hydrogen engine is described. The control method is optimized for the control method when the ammonia-hydrogen engine is in a starting condition and in a running condition. The ammonia-hydrogen engine provided by the present application comprises an ammonia pressure reducing valve 3, an ammonia pressure increasing pump 4, a hydrogen pressure reducing valve 6, a hydrogen injector 8, an ammonia injector 9, an intake port 10, a spark plug 11, a combustion chamber 12, an engine cylinder head 13, an exhaust port 14 and a controller. The corresponding combustion system of the ammonia-hydrogen engine is configured with an ammonia storage tank 1, an ammonia pipeline 2, a hydrogen storage tank 5 and a hydrogen pipeline 7.

[0047] When the ammonia-hydrogen engine is in the starting condition, the control method comprises the following steps:

[0048] 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 12, and the ammonia-hydrogen engine is in idle operation;

[0049] S2, after the ammonia-hydrogen engine is successfully started, the motor is disconnected, ammonia and hydrogen are used as fuel, so that a hydrogen, ammonia and air mixture environment is formed in the combustion chamber 12, and the ammonia-hydrogen engine is separated from the idle operation;

[0050] When the ammonia-hydrogen engine is in the running condition, the control method comprises the following steps:

[0051] S3, obtain a first temperature of the cooling liquid and / or a second temperature of the lubricating oil used by the ammonia-hydrogen engine, and adjust the ammonia-hydrogen engine to a corresponding condition according to the first temperature and / or the second temperature.

[0052] It should be understood that the above control method is realized by the controller equipped in the ammonia-hydrogen engine, and the above control method can be made into software and stored in the controller to control the working state of the ammonia-hydrogen engine.

[0053] Specifically, when the ammonia-hydrogen engine is in a starting condition, the ammonia-hydrogen engine first uses pure hydrogen as fuel, and uses the easy-to-ignite characteristics of hydrogen to achieve rapid starting of the ammonia-hydrogen engine. In this stage, the controller controls the hydrogen pressure reducing valve 6 to a suitable pressure, and the controller controls the hydrogen injector 8 to inject gaseous hydrogen into the intake port 10 during the intake stroke, and the hydrogen and air are preliminarily mixed in the intake port 10 and then enter the combustion chamber 12, the movement of the piston drives the airflow in the combustion chamber 12, and promotes the 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 small load condition that can be stably operated, and successfully starts and enters idle operation. In this stage, the advantages of hydrogen, such as low minimum ignition energy, fast combustion speed, high dilution limit, and short flame quenching distance, can be fully utilized, and even in the cold state of the engine, rapid starting can be achieved, and pure hydrogen small load non-knock operation can be achieved with a lean burn strategy, avoiding the problem of difficult cold start of ammonia engine.

[0054] When the ammonia-hydrogen engine is successfully started and in idle operation, the motor is disconnected, and the ammonia-hydrogen engine uses ammonia+hydrogen as fuel, and by using ammonia fuel to replace part or all of the hydrogen fuel, the low-cost ammonia fuel can be used to reduce the use cost of the engine. In this stage, the controller controls the ammonia pressure reducing valve 3, the ammonia booster pump 4, and the hydrogen pressure reducing valve 6 to a suitable pressure according to the injection pressure requirement, and increases the speed of the ammonia-hydrogen engine. In this stage, ammonia+hydrogen is used as fuel, a high compression ratio and a medium-high load operation strategy is adopted to promote the combustion of ammonia by using high temperature at the top dead center of compression, and hydrogen premixing and spark ignition are used to ignite the ammonia fuel, achieving a spark- compression efficient combustion organization mode, which is beneficial to improve the combustion effect of low-activity ammonia, and at the same time, the strong anti-knock ability of ammonia is utilized to realize stable and non-knock operation of the engine under high compression ratio and large load conditions.

[0055] It can be seen that, when the ammonia-hydrogen engine is in a starting state, the easy-to-burn hydrogen is first used as fuel, so that the hydrogen fuel and air form a mixture, thereby facilitating the rapid starting of the ammonia-hydrogen engine and idle operation. Then, 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 working 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.

[0056] When the ammonia-hydrogen engine is in the running condition, the speed, load and fuel composition are adjusted according to the current hybrid system power demand, so that the engine runs in the high thermal efficiency interval, and the running condition is dynamically adjusted according to the engine state, specifically: the water temperature of the cooling liquid used by the current ammonia-hydrogen engine and the oil temperature of the lubricating oil used are read every 30 seconds, the target working condition interval of the highest thermal efficiency permitted under the current ammonia-hydrogen engine temperature condition is updated based on the system preset parameters according to the current hybrid system power demand, and the target working condition interval is switched to run. In this stage, ammonia is used as the main fuel, and the energy proportion of ammonia in the fuel is as high as possible under the condition of meeting the stable operation of the ammonia-hydrogen engine, and even pure ammonia is used as the fuel. The advantages of ammonia, such as easy liquefaction and low storage and transportation cost, can be fully utilized to reduce the fuel consumption cost of the engine, and the advantages of liquid ammonia, such as high volume energy density, can be fully utilized to extend the vehicle range by storing liquid ammonia fuel, and the shortcomings of high cost and short range of hydrogen engine vehicles are avoided.

[0057] To switch to the new target working condition interval, the controller controls 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 to the appropriate working state, so as to adjust the speed, load and fuel composition of the ammonia-hydrogen engine.

[0058] It can be seen that the control method of the ammonia-hydrogen engine provided by the application optimizes the control method of the ammonia-hydrogen engine in the starting condition and the running condition. When the ammonia-hydrogen engine is in the starting condition, the motor drives the crankshaft to rotate, hydrogen is used as fuel, a hydrogen and air mixture environment is formed in the combustion chamber 12, and the ammonia-hydrogen engine is in idle operation, so that the ammonia-hydrogen engine can be started quickly. After the ammonia-hydrogen engine is successfully started, the motor is disconnected, ammonia and hydrogen are used as fuel, a hydrogen, ammonia and air mixture environment is formed in the combustion chamber 12, and the ammonia-hydrogen engine is separated from the idle operation, so that the use cost of the ammonia-hydrogen engine is reduced. When the ammonia-hydrogen engine is in the running condition, the first temperature of the cooling liquid used by the ammonia-hydrogen engine and / or the second temperature of the lubricating oil are obtained, and the ammonia-hydrogen engine is adjusted to the corresponding working condition according to the first temperature and / or the second temperature, so as to improve the thermal efficiency of the ammonia-hydrogen engine.

[0059] In one of the embodiments of the present application, when the ammonia-hydrogen engine is in operation, and after the first temperature of the cooling liquid and / or the second temperature of the lubricating oil used by the ammonia-hydrogen engine is obtained, and the operation condition of the ammonia-hydrogen engine is adjusted according to the first temperature and / or the second temperature, that is, after step S3, it further includes: S4, obtaining the current cycle fluctuation rate of the ammonia-hydrogen engine, and adjusting the operation condition of the ammonia-hydrogen engine according to the current cycle fluctuation rate of the ammonia-hydrogen engine. Since the corresponding condition is switched to in step S3, the condition to be adjusted is obtained by experience summary or table lookup, therefore, step S4 further adjusts the operation condition of the engine according to the current cycle fluctuation rate of the ammonia-hydrogen engine, so as to improve the operation efficiency of the ammonia-hydrogen engine

[0060] In one of the embodiments of the present application, the current cycle fluctuation rate of the ammonia-hydrogen engine is obtained, and the operation condition of the ammonia-hydrogen engine is adjusted according to the current cycle fluctuation rate of the ammonia-hydrogen engine, that is, step S4 specifically includes: S41, presetting a maximum cycle fluctuation rate and a minimum cycle fluctuation rate; S42, if the current cycle fluctuation rate of the ammonia-hydrogen engine is between the preset maximum cycle fluctuation rate and the minimum cycle fluctuation rate, maintaining the current operation 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, increasing the energy proportion of hydrogen in the fuel; if the current cycle fluctuation rate of the ammonia-hydrogen engine is less than the preset minimum cycle fluctuation rate, reducing the energy proportion of hydrogen in the fuel.

[0061] In the above embodiment, by presetting the maximum cycle fluctuation rate (hereinafter referred to as "maximum value") and the minimum cycle fluctuation rate (hereinafter referred to as "minimum value"), the operation 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.

[0062] If the current cycle fluctuation rate is between the maximum value and the minimum value, it is considered that the current operation condition of the ammonia-hydrogen engine is appropriate, and no adjustment is needed.

[0063] 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 are 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, and the controller controls the ammonia injector 9 to reduce the injection pulse width to reduce the ammonia fuel supply flow, so as to increase the energy proportion of hydrogen in the fuel, until 100% (at this time, the engine uses pure hydrogen as fuel).

[0064] If the current cycle fluctuation rate is less than the minimum value, it means that the control strategy of the combustion system can form very sufficient combustion in the combustion chamber 12 at this time, and there is a surplus of hydrogen combustion-supporting effect, so 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 operation of the engine, and the advantage of easy liquefaction, low storage and transportation cost of ammonia is used to reduce the use cost of the engine. Therefore, the controller controls the hydrogen injector 8 to reduce the injection pulse width to reduce the hydrogen fuel supply flow, and controls the ammonia injector 9 to increase the injection pulse width to increase the ammonia fuel supply flow, so that the energy proportion of hydrogen in the fuel is reduced to 0% (at this time, the engine uses pure ammonia as fuel).

[0065] In one embodiment of the present application, if the current ammonia-hydrogen engine cycle fluctuation rate is greater than the preset maximum cycle fluctuation rate, the energy proportion of hydrogen in the fuel is increased to 100%, and if the ammonia-hydrogen engine cycle fluctuation rate is still greater than the preset maximum cycle fluctuation rate, the ammonia-hydrogen engine operating power and / or speed 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 pressure increasing 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, improve the engine load, and make the engine enter a working condition point which is more easy to be stable, until the cycle fluctuation rate is less than the maximum value.

[0066] In one embodiment of the present application, when the ammonia-hydrogen engine is in the starting condition, 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 indicated mean effective pressure of the ammonia-hydrogen engine is less than 0.6 MPa, determining that the ammonia-hydrogen engine is in the idling operation of the small load condition, and when the indicated mean effective pressure of the ammonia-hydrogen engine is greater than 0.9 MPa and less than 1.2 MPa, determining that the ammonia-hydrogen engine is in the medium-high load condition and is separated from the idling operation. In step S1, when the indicated mean effective pressure of the ammonia-hydrogen engine is less than 0.6 MPa, it is determined that the ammonia-hydrogen engine is in the idling operation, that is, the ammonia-hydrogen engine uses hydrogen as fuel, and a hydrogen and air mixture environment is formed in the combustion chamber 12; in step S2, when the indicated mean effective pressure of the ammonia-hydrogen engine is greater than 0.9 MPa and less than 1.2 MPa, it is determined that the ammonia-hydrogen engine is in the medium-high load condition separated from the idling operation, that is, the motor is disconnected, ammonia and hydrogen are used as fuel, and a hydrogen, ammonia and air mixture environment is formed in the combustion chamber 12.

[0067] In one embodiment of the present application, the preset maximum cycle fluctuation rate is in the range of 4%-6%, and the preset minimum cycle fluctuation rate is in the range of 0.5%-2%.

[0068] As Figure 3As shown, the application also provides an ammonia-hydrogen engine. The ammonia-hydrogen engine comprises a combustion chamber 12, an air inlet passage 10, an exhaust passage 14, a spark plug 11, an ammonia pressure reducing valve 3, an ammonia pressure increasing pump 4, a hydrogen pressure reducing valve 6, an ammonia injector 9, a hydrogen injector 8 and a controller. The air inlet passage 10 and the exhaust passage 14 are respectively communicated with the combustion chamber 12, the ammonia injector 9 and the hydrogen injector 8 are both connected to the same air inlet passage 10, the spark plug 11 extends to the combustion chamber 12, the ammonia pressure reducing valve 3 and the ammonia pressure increasing 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-mentioned embodiments of the application and is electrically connected with the ammonia pressure reducing valve 3, the ammonia pressure increasing pump 4, the hydrogen pressure reducing valve 6, the ammonia injector 9, the hydrogen injector 8 and the spark plug 11.

[0069] For the ammonia-hydrogen engine of the present embodiment, the step S2 specifically controls the process as follows:

[0070] The controller controls the hydrogen injector 8 and the ammonia injector 9 to inject hydrogen and ammonia fuel into the air inlet passage 10 respectively during the intake stroke, the hydrogen and ammonia fuel preliminarily mix with air in the air inlet passage 10 and then enter the combustion chamber 12, the movement of the piston drives the airflow in the combustion chamber 12 and promotes the further mixing of the hydrogen, ammonia fuel and air in the combustion chamber 12, thereby forming the ammonia / hydrogen / air mixture with high energy density in the combustion chamber 12, so that the engine is in the medium-high load operating condition with high efficiency and is separated from the idling operation to enter the normal operation.

[0071] Specifically, the ammonia-hydrogen engine provided by the application is characterized in that the ammonia injector 9 and the hydrogen injector 8 are arranged in the same air inlet passage 10; and the engine cylinder head 13 is reserved with holes for mounting the air inlet passage 10, the spark plug 11 and the exhaust passage 14.

[0072] The opening for mounting the air inlet passage 10 or the exhaust passage 14 is optionally arranged on the top surface or the side surface of the engine cylinder head 13, the combustion chamber 12 is respectively communicated with the air inlet passage 10 and the exhaust passage 14, the opening for mounting the spark plug 11 is arranged on the top surface of the engine cylinder head 13, the spark plug 11 is mounted 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. The air inlet passage 10 is reserved with holes for mounting the hydrogen injector 8 and the ammonia injector 9.

[0073] The ammonia storage tank 1 stores ammonia fuel, is provided with an outlet and is connected with the inlet of the ammonia pressure reducing valve 3 and the ammonia pressure increasing pump 4 through the ammonia pipeline 2, the outlet of the ammonia pressure reducing valve 3 and the ammonia pressure increasing pump 4 is connected with the ammonia injector 9 through the ammonia pipeline 2, and the outlet of the ammonia injector 9 is arranged in the air inlet passage 10. In actual use, the ammonia fuel is in gas phase or liquid phase, the ammonia in the ammonia storage tank 1 is reduced in pressure by the ammonia pressure reducing valve 3 or is increased in pressure by the ammonia pressure increasing pump 4 and is injected into the air inlet passage 10 through the ammonia injector 9.

[0074] The angle between the axes of the hydrogen injector 8 and the ammonia injector 9 is optionally parallel or non-parallel, the relationship between the hydrogen injector 8 and the ammonia injector 9 and the surface of the intake passage 10 is optionally vertical or non-vertical, and the hydrogen injector 8 or the ammonia injector 9 is optionally arranged closer to one side of the combustion chamber 12.

[0075] The hydrogen injector 8 and the ammonia injector 9 are arranged in the intake passage 10 in any mode that can achieve fixed connection, and the embodiments of the present application do not make any limitation thereon, for example, the hydrogen injector 8 and the ammonia injector 9 are fixedly installed in the intake passage 10 by screws.

[0076] The compression ratio of the ammonia-hydrogen engine is 20-25, and the injection pressure of the ammonia injector 9 is 0.4-30 MPa.

[0077] As shown in Figure 4 The present application also provides an ammonia-hydrogen engine. The ammonia-hydrogen engine comprises a combustion chamber 12, an intake passage 10, an exhaust passage 14, a spark plug 11, an ammonia pressure reducing valve 3, an ammonia pressure increasing 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 communicated with 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 into the combustion chamber 12, the ammonia pressure reducing valve 3 and the ammonia pressure increasing pump 4 are connected in parallel between an ammonia tank 1 and the ammonia injector 9, and the hydrogen pressure reducing valve 6 is connected between a hydrogen tank 5 and the hydrogen injector 8. The controller executes the control method of the ammonia-hydrogen engine provided in the above embodiments of the present application, and is electrically connected with the ammonia pressure reducing valve 3, the ammonia pressure increasing pump 4, the hydrogen pressure reducing valve 6, the ammonia injector 9, the hydrogen injector 8, and the spark plug 11.

[0078] For the ammonia-hydrogen engine of the present embodiment, the specific control process of step S2 is as follows:

[0079] The controller controls the hydrogen injector 8 to inject hydrogen fuel into the intake passage 10 during the intake stroke, and the hydrogen fuel and air are preliminarily mixed in the intake passage 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 movement of the piston drives the airflow in the combustion chamber 12 and promotes the further mixing of hydrogen, ammonia fuel and air in the combustion chamber 12, so as to form a high-energy-density ammonia / hydrogen / air mixture in the combustion chamber 12, so that the engine is in a medium-high load operating condition that can be efficiently operated, and is separated from idling operation and enters normal operation.

[0080] Specifically, the present application provides an ammonia-hydrogen engine, wherein the ammonia injector 9 is arranged in the engine cylinder head 13; and the engine cylinder head 13 is pre-provided with holes for installing the ammonia injector 9, the intake passage 10, the spark plug 11, and the exhaust passage 14.

[0081] The opening for mounting the ammonia injector 9 is located on the top surface of the engine cylinder head 13. The opening for mounting the intake manifold 10 or exhaust manifold 14 is optionally located on the top surface or side of the engine cylinder head 13. The combustion chamber 12 communicates with both the intake manifold 10 and the exhaust manifold 14. The opening for mounting the spark plug 11 is located on the top surface of the engine cylinder head 13. The spark plug 11 is mounted at the geometric center of the combustion chamber 12, and its ignition electrode is located within the combustion chamber 12. Holes are pre-drilled in the intake manifold 10 for mounting the hydrogen injector 8.

[0082] The ammonia storage tank 1 stores ammonia fuel. The ammonia storage tank 1 is equipped with an outlet and is connected to the inlet of the ammonia pressure reducing valve 3 and the ammonia booster pump 4 through the ammonia pipeline 2. The outlet of the ammonia pressure reducing valve 3 and the ammonia booster pump 4 is connected to the ammonia injector 9 through the ammonia pipeline 2. The outlet of the ammonia injector 9 is located in the combustion chamber 12. In actual use, the ammonia fuel is in the gas phase or liquid phase. The ammonia in the ammonia storage tank 1 is depressurized by the ammonia pressure reducing valve 3 or pressurized by the ammonia booster pump 4, and then injected into the combustion chamber 12 through the ammonia injector 9.

[0083] The hydrogen injector 8 can be positioned vertically or non-vertically relative to the intake manifold 10, the axial angle between the ammonia injector 9 and the spark plug 11 can be parallel or non-parallel, the ammonia injector 9 can be positioned vertically or non-vertically relative to the surface of the engine cylinder head 13, and the ammonia injector 9 can be positioned closer to the intake manifold 10 or the exhaust manifold 14.

[0084] The hydrogen injector 8 can be installed in the intake manifold 10 and the ammonia injector 9 can be installed in the engine cylinder head 13 in any way that can achieve a fixed connection. This embodiment of the invention does not limit this in any way. For example, the hydrogen injector 8 can be fixedly installed in the intake manifold 10 by screws and the ammonia injector 9 can be fixedly installed in the engine cylinder head 13 by screws.

[0085] The compression ratio of the ammonia-hydrogen engine is 20-25; the injection pressure of the ammonia injector 9 is 0.4-30 MPa.

[0086] for Figure 3 and Figure 4 Two types of ammonia-hydrogen engines:

[0087] Hydrogen fuel is stored in hydrogen storage tank 5. The top of hydrogen storage tank 5 is provided with an outlet, which is connected to the inlet of hydrogen pressure reducing valve 6 through hydrogen pipeline 7. The outlet of hydrogen pressure reducing valve 6 is connected to hydrogen injector 8 through hydrogen pipeline 7. The outlet of hydrogen injector 8 is located in air intake duct 10. In actual use, hydrogen fuel is in gas phase. After the hydrogen in hydrogen storage tank 5 is depressurized by hydrogen pressure reducing valve 6, it is injected into air intake duct 10 through hydrogen injector 8.

[0088] 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 application does not make any limitation on the specific position of the opening.

[0089] The ammonia decompression valve 3, the ammonia booster pump 4, the hydrogen decompression valve 6, the ammonia injector 9, the hydrogen injector 8 and the spark plug 11 are electrically connected with the controller.

[0090] Optionally, the ammonia pipeline 2 and the hydrogen pipeline 7 are both stainless steel pipes.

[0091] Optionally, the engine compression ratio of the ammonia-hydrogen engine combustion system is 20-25.

[0092] Optionally, the intake stroke is 180-360 degrees of the crankshaft angle before the compression top dead center.

[0093] Optionally, the early compression stroke is 90-180 degrees of the crankshaft angle before the compression top dead center.

[0094] In the embodiment of the present application, the ammonia fuel can adopt a low-cost ammonia intake port 10 injection mode (i.e., the ammonia-hydrogen engine as shown in FIG. 1), or a high-power-density ammonia in-cylinder direct injection mode (i.e., the ammonia-hydrogen engine as shown in FIG. 2). Figure 3 Figure 4 The former has less engine structure modification and is convenient for quick use, and the latter can realize greater engine charge coefficient and power density, and is beneficial to further expand the engine performance boundary.

[0095] The present application also provides an ammonia-hydrogen engine combustion system, 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-mentioned embodiment of the present application.

[0096] As known from the above description, the embodiment of the present application uses pure hydrogen as fuel in the engine starting stage, can fully utilize the advantages of hydrogen, such as low minimum ignition energy, fast combustion speed, high dilution limit and short flame quenching distance, and can realize fast starting even in the cold engine state, realizes pure hydrogen small load non-knock operation with the dilution strategy, and avoids the problem of difficult cold start of the ammonia engine.

[0097] In the embodiment of the present application, the engine uses ammonia+hydrogen as fuel in the conventional operation stage, adopts a high compression ratio and medium-high load operation strategy to promote the combustion of ammonia by using high temperature in the cylinder at the compression top dead center, and uses hydrogen premixing and spark ignition to ignite the ammonia fuel, realizes the ignition-compression high-efficiency combustion organization mode, is beneficial to improve the combustion effect of low-activity ammonia, and realizes stable non-knock operation of the engine under high compression ratio and large load conditions by using the strong anti-knock ability of ammonia.

[0098] ​In the embodiment of the present application, ammonia is used as the main fuel in the normal operation stage of the engine, and the energy proportion of ammonia in the fuel is as high as possible under the condition of meeting the stable operation of the engine, even using pure ammonia as the fuel, so that the advantages of ammonia, such as easy liquefaction and low storage and transportation cost, can be fully utilized, the fuel consumption cost of the engine is reduced, the advantages of high volume energy density of liquid ammonia are fully utilized, the vehicle endurance mileage is prolonged through the storage of liquid ammonia fuel, and the shortcomings of high use cost and short endurance mileage of the hydrogen engine vehicle are avoided.

[0099] In the embodiment of the present application, the ammonia fuel can adopt a low-cost ammonia intake port 10 injection mode, or a high-power-density ammonia in-cylinder direct injection mode, the former has less engine structure modification and is convenient for quick use, and the latter can realize greater engine charge coefficient and power density, which is beneficial to further expand the performance boundary of the engine.

[0100] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A control method of an ammonia hydrogen engine, characterized by, Comprising: When the ammonia-hydrogen engine is in the starting condition, comprising: S1, control the motor to drive the crankshaft to rotate, use hydrogen as fuel, so that the hydrogen and air mixture environment is formed in the combustion chamber (12), and the ammonia-hydrogen engine is in idle operation; S2, after the ammonia-hydrogen engine starts successfully, disconnect the motor, use ammonia and hydrogen as fuel, so that the hydrogen, ammonia and air mixture environment is formed in the combustion chamber (12), and the ammonia-hydrogen engine is separated from the idle operation; When the ammonia-hydrogen engine is in the running condition, comprising: S3, obtain the first temperature of the cooling liquid used by the ammonia-hydrogen engine and / or the second temperature of the lubricating oil, and adjust the ammonia-hydrogen engine to the corresponding condition according to the first temperature and / or the second temperature; When the ammonia-hydrogen engine is in the running condition, and after the step of obtaining the first temperature of the cooling liquid used by the ammonia-hydrogen engine and / or the second temperature of the lubricating oil, and adjusting the ammonia-hydrogen engine to the corresponding condition according to the first temperature and / or the second temperature, further comprising: S4, obtain the current ammonia-hydrogen engine cycle fluctuation rate, and adjust the running condition of the ammonia-hydrogen engine according to the current ammonia-hydrogen engine cycle fluctuation rate; The step of obtaining the current ammonia-hydrogen engine cycle fluctuation rate and adjusting the running condition of the ammonia-hydrogen engine according to the current ammonia-hydrogen engine cycle fluctuation rate specifically comprises: S41, preset the maximum cycle fluctuation rate and the minimum cycle fluctuation rate; S42, if the current ammonia-hydrogen engine cycle fluctuation rate is between the preset maximum cycle fluctuation rate and the minimum cycle fluctuation rate, the current running condition of the ammonia-hydrogen engine is maintained; If the current ammonia-hydrogen engine cycle fluctuation rate is greater than the preset maximum cycle fluctuation rate, increase the energy proportion of hydrogen in the fuel; If the current ammonia-hydrogen engine cycle fluctuation rate is less than the preset minimum cycle fluctuation rate, reduce the energy proportion of hydrogen in the fuel.

2. The control method of the ammonia-hydrogen engine according to claim 1, characterized by, If the current ammonia-hydrogen engine cycle fluctuation rate is greater than the preset maximum cycle fluctuation rate, increase the energy proportion of hydrogen in the fuel to 100%, and if the ammonia-hydrogen engine cycle fluctuation rate is still greater than the preset maximum cycle fluctuation rate, reduce the running power and / or speed of the ammonia-hydrogen engine until the cycle fluctuation rate is less than the preset maximum cycle fluctuation rate.

3. The control method of the ammonia-hydrogen engine according to claim 1, characterized by, When the ammonia-hydrogen engine is in the starting condition, specifically comprising: Determine the excess air coefficient of the ammonia-hydrogen engine to be 1.0-2.5, and when the indicated mean effective pressure of the ammonia-hydrogen engine is less than 0.6 MPa, determine that the ammonia-hydrogen engine is in the idle operation of the small load condition, and when the indicated mean effective pressure of the ammonia-hydrogen engine is greater than 0.9 MPa and less than 1.2 MPa, determine that the ammonia-hydrogen engine is in the medium-high load condition and is separated from the idle operation.

4. The ammonia-hydrogen engine control method according to claim 1 or 2, characterized by, The preset maximum cycle fluctuation rate has a value range of 4%-6%, and the preset minimum cycle fluctuation rate has a value range of 0.5%-2%.

5. An ammonia-hydrogen engine, characterized by Comprising: The combustion chamber (12), the intake port (10), the exhaust port (14), the spark plug (11), the ammonia pressure reducing valve (3), the ammonia pressure increasing pump (4), the hydrogen pressure reducing valve (6), the ammonia injector (9), the hydrogen injector (8), and the controller; The intake passage (10) and the exhaust passage (14) are communicated with the combustion chamber (12) respectively, the ammonia injector (9) and the hydrogen injector (8) are both connected 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 pressure increasing 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 4, and is electrically connected with the ammonia pressure reducing valve (3), the ammonia pressure increasing pump (4), the hydrogen pressure reducing valve (6), the ammonia injector (9), the hydrogen injector (8) and the spark plug (11).

6. The ammonia-hydrogen engine according to claim 5, wherein The compression ratio of the ammonia-hydrogen engine is 20-25, and the injection pressure of the ammonia injector (9) is 0.4-30 MPa.

7. An ammonia-hydrogen engine, characterized by It comprises: a combustion chamber (12), an intake passage (10), an exhaust passage (14), a spark plug (11), an ammonia pressure reducing valve (3), an ammonia pressure increasing 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 communicated with the combustion chamber (12) respectively, the ammonia injector (9) and the hydrogen injector (8) are both connected 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 pressure increasing 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 4, and is electrically connected with the ammonia pressure reducing valve (3), the ammonia pressure increasing 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, wherein The compression ratio of the ammonia-hydrogen engine is 20-25, and the injection pressure of the ammonia injector (9) is 0.4-30 MPa.

9. A combustion system for an ammonia-hydrogen engine, characterized by It comprises: an ammonia storage tank (1), an ammonia pipeline (2), a hydrogen storage tank (5), a hydrogen pipeline (7) and the ammonia-hydrogen engine according to any one of claims 5 to 8; The ammonia storage tank (1) is connected with the ammonia injector (9) through the ammonia pipeline (2), and the hydrogen storage tank (5) is connected with the hydrogen injector (8) through the hydrogen pipeline (7).

Images