Hydrogen internal combustion engine capable of controlling total flow area of spray holes of pre-combustion chamber and control method

Abstract

The invention provides a hydrogen internal combustion engine capable of controlling the total flow area of spray holes of a pre-combustion chamber and a control method, widens the stable operation interval of a heavy-duty hydrogen internal combustion engine, and belongs to the field of hydrogen internal combustion engines. The hydrogen internal combustion engine is characterized in that a set of driving motor (7) fixed on a pre-combustion chamber transition area and a cylinder cover, a pre-combustion chamber sealing block (8) for connecting a pre-combustion chamber throat sliding block (9) and the driving motor (7), and an electronic control unit (5) are added; the total flow area of spray holes of the pre-combustion chamber is changed by adjusting the injection proportion of a pre-combustion chamber fuel nozzle (11) and a main combustion chamber fuel nozzle (13) in the pre-combustion chamber (12) and controlling the throat diameter of the pre-combustion chamber through a driving motor (7), and different functions of the pre-combustion chamber under different working conditions are achieved. Two combustion modes of jet flow flame ignition combustion and diffusion combustion adapting to different working condition requirements are achieved, so that the working efficiency and the heat efficiency of the engine are improved, and the service life can be prolonged.

Description

Technical Field

[0001] The present invention provides an internal combustion engine with controllable total flow area of a pre-combustion chamber nozzle and a control method. The specific contents include a device for controlling the throat diameter of the pre-combustion chamber and a coordinated control method of the pre-combustion chamber combustion law and different operating conditions. The method broadens the stable operating range of the hydrogen internal combustion engine and belongs to the field of hydrogen internal combustion engines. Background Art

[0002] With the increasing global demand for clean energy, hydrogen energy, as an efficient and clean energy carrier, has gradually become a research hotspot in the field of internal combustion engines. Due to its zero-carbon emissions and high energy density, hydrogen internal combustion engines are considered to be one of the important development directions of future power systems. However, hydrogen internal combustion engines still face many technical challenges in practical applications, especially in terms of combustion control and stability under different operating conditions. Although the combustion characteristics of hydrogen fuel (such as high flame propagation speed and low ignition energy requirement) are conducive to rapid combustion, they are also prone to cause problems such as pre-ignition, detonation and deflagration, which are particularly prominent under high load conditions.

[0003] The pre-combustion chamber is a key technology for controlling the combustion process in internal combustion engines. Limited by the limitations of diesel high-pressure pumps and nozzle technology, traditional diesel engines often utilize a pre-combustion chamber with a large nozzle flow area. This injects all the diesel into the pre-combustion chamber. The high pressure generated by the combustion of a small amount of diesel in the pre-combustion chamber during the compression stroke forces the diesel into the main combustion chamber, where it undergoes controlled diffusion combustion. Advanced spark-ignition internal combustion engines also utilize a pre-combustion chamber with a smaller nozzle flow area to organize jet ignition. This utilizes the high ignition energy and multi-point ignition characteristics of the jet ignition process to ignite low-reactivity mixtures in the main combustion chamber or increase the heat release rate of the mixture.

[0004] In the prior art, the total flow area of the nozzles in the pre-combustion chamber of an internal combustion engine is usually fixed, which limits its adaptability to variable internal combustion engine operating conditions and its ability to control the combustion process. Under low and medium load conditions of an internal combustion engine, using a pre-combustion chamber with a small nozzle flow area for jet ignition combustion can reduce the material exchange between the pre-combustion chamber and the main combustion chamber, increase the pressure difference, increase the jet velocity, lengthen the jet penetration distance, and increase the disturbance in the main combustion chamber. This broadens the lean burn limit of the fuel, thereby improving combustion efficiency and reducing heat transfer losses and NOx emissions. It can also utilize its high-speed jet to achieve multi-point ignition in the main combustion chamber, thereby increasing the heat release rate and improving the thermal efficiency of the internal combustion engine.

[0005] Under high-load, high-speed operating conditions, diffusion combustion guided by a pre-combustion chamber with a larger nozzle flow area is suitable. This can reduce throttling losses during the jet flow, allowing more hydrogen to enter the main combustion chamber for diffusion combustion during the jet flow process rather than being consumed in the pre-combustion chamber. Providing an appropriate jet velocity and a larger jet volume facilitates the entrainment of oxygen by the wall-guided flow formed by the hydrogen jet after impacting the piston, accelerating the diffusion combustion rate and avoiding incomplete combustion. Due to the large load variations in actual operation, a fixed pre-combustion chamber nozzle flow area cannot meet the optimal combustion requirements under different operating conditions, leading to problems such as unstable combustion, low efficiency, and increased emissions. Summary of the Invention

[0006] The present invention addresses the difficulty in flexibly changing the precombustion chamber nozzle area faced by existing heavy-duty hydrogen internal combustion engines. Under low-load conditions, a precombustion chamber with a small nozzle flow area is required to organize high-energy, multi-point jet ignition to guide premixed combustion, while under high-load conditions, a precombustion chamber with a large nozzle flow area is required to guide controlled diffusion combustion. The present invention provides a heavy-duty internal combustion engine with controllable precombustion chamber nozzle total flow area and a control method.

[0007] The present invention adopts the following technical solutions:

[0008] An internal combustion engine based on a variable pre-combustion chamber nozzle total flow area comprises a cylinder head (2), a main combustion chamber (4), a piston (3), a cylinder pressure sensor (6) mounted on the internal combustion engine body, an intake duct (16), an exhaust duct (1), and a pre-combustion chamber (12) mounted on the cylinder head (2), and is characterized in that the throat of the pre-combustion chamber (12) is square, the front and rear walls are fixed, and the left and right side walls are pre-combustion chamber throat sliders (9), a drive motor (7) is mounted on the transition zone of the pre-combustion chamber (12) and the cylinder head (2), and a slide rail is provided on the drive motor (7). The pre-combustion chamber sealing block (8) is mounted on the slide rail of the driving motor (7). The pre-combustion chamber sealing block (8) is rigidly connected to the pre-combustion chamber throat slider (9). The pre-combustion chamber sealing block (8) and the pre-combustion chamber throat slider (9) can move left and right under the drive of the driving motor (7) to control the total flow area of the pre-combustion chamber nozzle. T represents the maximum throat diameter that the driving motor (7) can reach by driving the pre-combustion chamber throat slider (9) through the pre-combustion chamber sealing block (8). When the pre-combustion chamber throat slider (9) moves to T, the total nozzle area of the pre-combustion chamber is defined as S. max , B. represents the minimum throat diameter that can be reached by the driving motor (7) through the pre-combustion chamber sealing block (8) to drive the pre-combustion chamber throat slider (9). When the pre-combustion chamber throat slider (9) moves to B., the total nozzle area of the pre-combustion chamber is defined as S minThe spark plug (10) and the pre-combustion chamber fuel nozzle (11) are respectively installed on the top cover of the pre-combustion chamber (12); the fuel stored in the fuel bottle (18) is decompressed by the pressure reducer (17) and connected to the pre-combustion chamber fuel nozzle (11) and the main combustion chamber fuel nozzle (13) through pipelines; an intake pressure sensor (14) and a temperature sensor (15) are respectively installed on the exhaust duct (16).

[0009] The electronic control unit (5) obtains a rotation speed signal a by connecting or communicating with an existing rotation speed sensor in the internal combustion engine;

[0010] The electronic control unit (5) obtains the load signal b by connecting or communicating with an existing control handle or pedal in the internal combustion engine;

[0011] The electronic control unit (5) obtains an output torque signal c by connecting or communicating with an existing digital torque sensor in the internal combustion engine;

[0012] The electronic control unit (5) is connected to the cylinder pressure sensor (6) via a wire, and determines the combustion chamber pressure in the main combustion chamber (4) by receiving the cylinder pressure signal d;

[0013] The electronic control unit (5) is connected to the spark plug (10) via a wire and controls the spark plug (6) to spark by sending an ignition signal g;

[0014] The electronic control unit (5) is connected to the pre-combustion chamber fuel nozzle (11) through a wire, and controls the injection of the pre-combustion chamber fuel nozzle (16) by sending a pre-combustion chamber hydrogen nozzle control signal h;

[0015] The electronic control unit (5) is connected to the main combustion chamber fuel nozzle (13) through a wire, and controls the main combustion chamber fuel nozzle (13) to spray by sending a main combustion chamber hydrogen nozzle control signal i;

[0016] The electronic control unit (5) is connected to the four drive motors (7) via wires, and controls the movement of the pre-combustion chamber sealing block (8) on the slide rail of the drive motor (7) by sending a motion signal f from the drive motor (7). The electronic control unit (5) determines the actual position of the pre-combustion chamber sealing block (8) by receiving a position feedback signal e sent by the drive motor (7), thereby completing closed-loop control of the drive motor (7);

[0017] The electronic control unit (5) is connected to the temperature sensor (14) via a wire, and obtains the temperature of the fuel entering the main combustion chamber (2) by receiving the temperature signal k;

[0018] The electronic control unit (5) is connected to the intake pressure sensor (15) via a wire and obtains the pressure in the intake passage (15) by receiving the intake pressure signal j.

[0019] A method for controlling the total flow area of a controllable pre-combustion chamber nozzle hole comprises the following steps:

[0020] According to the actual effect of the total flow area of different pre-combustion chambers (12), a control method for the total flow area of the nozzle holes of a controllable pre-combustion chamber can be divided into a jet ignition combustion control method and a diffusion combustion control method, which are respectively:

[0021] 1) Jet ignition combustion control method

[0022] The electronic control unit (5) determines the working state of the internal combustion engine through the load signal b. When the load rate (L) is lower than 40% (the load rate refers to the ratio of the actual power received by the electronic control unit (5) at a certain speed to the maximum rated power at that speed), the electronic control unit (5) determines that the engine is in a low-load state and adopts the jet ignition combustion control method. At this time, the electronic control unit (5) calculates the hydrogen injection amount in each working cycle according to formula (1):

[0023]

[0024] In formula (1), T is the temperature of the fuel entering the main combustion chamber (4) obtained by the electronic control unit (5) according to the temperature signal k, N is the internal combustion engine speed obtained by the electronic control unit (5) according to the speed signal a, P is the intake pressure obtained by the electronic control unit (5) according to the intake pressure signal j, and A is the cross-sectional area of the hydrogen nozzle.

[0025] The electronic control unit (5) controls the injection of the pre-combustion chamber fuel nozzle (11) and the main combustion chamber fuel nozzle (13) by sending a pre-combustion chamber hydrogen nozzle control signal h and a main combustion chamber hydrogen nozzle control signal i. At this time, the amount of hydrogen injected into the pre-combustion chamber is Amount of hydrogen injected into the main combustion chamber

[0026] The electronic control unit (5) controls the displacement of the pre-combustion chamber throat slider (9) according to equation (2).

[0027]

[0028] In formula (2), S max is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the maximum throat diameter T., S min is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the minimum throat diameter B., and L is the load rate.

[0029] When the electronic control unit (5) controls the pre-combustion chamber sealing block (8) to move on the slide rail of the drive motor (7) by sending a motion signal f of the drive motor (7), the electronic control unit (5) determines the actual position of the slide rail of the drive motor (7) by receiving a slide rail position feedback signal e sent by the drive motor (7). If the relative error between the pre-combustion chamber sealing block (8) provided by the drive motor position feedback signal and the target control displacement exceeds 10%, the electronic control unit (5) determines that there is a fault in the system and immediately sends a motion signal f of the drive motor (7) to instruct the pre-combustion chamber sealing block (8) to return to the T position to ensure safe and stable operation of the engine.

[0030] The electronic control unit (5) sends an ignition signal i to control the ignition timing of the spark plug (13) to be 5° crank angle before the top dead center. At the same time, the electronic control unit (13) obtains the cylinder pressure p by receiving the cylinder pressure signal c, and further calculates the pressure increase rate dp / dCA.

[0031] If the maximum pressure increase rate dp / dCA of the cycle is not greater than 0.2 MPa at this time, the electronic control unit (5) keeps the hydrogen injection amount in the pre-combustion chamber and the main combustion chamber, the ignition angle, the pre-combustion chamber push rod and other parameters unchanged. If the maximum pressure increase rate dp / dCA is greater than 0.2 MPa at this time, the electronic control unit (5) sends an ignition signal i to control the spark plug (6) to delay the ignition angle by 1° crank angle, that is, the ignition angle at this time is 6° crank angle before top dead center, until the nth maximum pressure increase rate dp / dCA is not greater than 0.2 MPa, and the ignition angle at this time is (5+n)° crank angle before top dead center.

[0032] 2) Diffusion combustion control method

[0033] The electronic control unit (5) determines the working state of the internal combustion engine through the load signal b. When the load rate (L) is lower than 40% (the load rate refers to the ratio of the actual power received by the electronic control unit (5) at a certain speed to the maximum rated power at that speed), the electronic control unit (5) determines that the engine is in a low-load state and adopts the jet ignition combustion control method. At this time, the electronic control unit (5) calculates the hydrogen injection amount in each working cycle according to formula (1):

[0034]

[0035] In formula (1), T is the temperature of the fuel entering the main combustion chamber (4) obtained by the electronic control unit (5) according to the temperature signal k, N is the internal combustion engine speed obtained by the electronic control unit (5) according to the speed signal a, P is the intake pressure obtained by the electronic control unit (5) according to the intake pressure signal j, and A is the cross-sectional area of the hydrogen nozzle.

[0036] The electronic control unit (5) controls the injection of the pre-combustion chamber fuel nozzle (11) and the main combustion chamber fuel nozzle (13) by sending a pre-combustion chamber hydrogen nozzle control signal h and a main combustion chamber hydrogen nozzle control signal i. At this time, the amount of hydrogen injected into the pre-combustion chamber is Amount of hydrogen injected into the main combustion chamber

[0037] The electronic control unit (5) controls the displacement of the pre-combustion chamber throat slider (9) according to equation (2).

[0038]

[0039] In formula (2), S max is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the maximum throat diameter T., S min is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the minimum throat diameter B., and L is the load rate.

[0040] When the electronic control unit (5) controls the pre-combustion chamber sealing block (8) to move on the slide rail of the drive motor (7) by sending a motion signal f of the drive motor (7), the electronic control unit (5) determines the actual position of the slide rail of the drive motor (7) by receiving a slide rail position feedback signal e sent by the drive motor (7). If the relative error between the pre-combustion chamber sealing block (8) provided by the drive motor position feedback signal and the target control displacement exceeds 10%, the electronic control unit (5) determines that there is a fault in the system and immediately sends a motion signal f of the drive motor (7) to instruct the pre-combustion chamber sealing block (8) to return to the T position to ensure safe and stable operation of the engine.

[0041] The electronic control unit (5) sends an ignition signal i to control the ignition timing of the spark plug (13) to be 5° crank angle before the top dead center. At the same time, the electronic control unit (13) obtains the cylinder pressure p by receiving the cylinder pressure signal c, and further calculates the pressure increase rate dp / dCA.

[0042] If the maximum pressure increase rate dp / dCA of the cycle is not greater than 0.2 MPa at this time, the electronic control unit (5) keeps the hydrogen injection amount in the pre-combustion chamber and the main combustion chamber, the ignition angle, the pre-combustion chamber push rod and other parameters unchanged. If the maximum pressure increase rate dp / dCA is greater than 0.2 MPa at this time, the electronic control unit (5) sends an ignition signal i to control the spark plug (6) to delay the ignition angle by 1° crank angle, that is, the ignition angle at this time is 6° crank angle before top dead center, until the nth maximum pressure increase rate dp / dCA is not greater than 0.2 MPa, and the ignition angle at this time is (5+n)° crank angle before top dead center.

[0043] The beneficial effect of the present invention is that it addresses the problem that the total flow area of the existing fixed pre-combustion chamber nozzle cannot adapt to the combustion control requirements of hydrogen internal combustion engines under different loads. The present invention proposes a hydrogen internal combustion engine with a controllable total flow area of the pre-combustion chamber nozzle and a control method. The invention adopts a movable pre-combustion chamber throat slider and cooperates with a drive motor to achieve dynamic adjustment of the pre-combustion chamber nozzle aperture and combustion organization mode under different load conditions. Under low speed and low load conditions, the total flow area of the pre-combustion chamber nozzle is reduced. By realizing jet flame ignition, the ignition energy can be effectively improved. At the same time, the total flow area is small, and less fuel is injected into the pre-combustion chamber at this time, which can reduce the loss in the pre-combustion chamber and further improve the combustion efficiency, thereby achieving lower emissions and higher fuel economy. Under high speed and high load conditions, the flow area of the pre-combustion chamber nozzle is increased, and the diffusion combustion method is adopted to avoid the detonation phenomenon caused by excessively high compression ratio and ensure the smooth operation of the engine. Furthermore, a variable pre-chamber nozzle total flow area control strategy allows the system to adjust the ignition angle in real time when internal engine pressure or the rate of pressure rise is excessive, reducing the mechanical and thermal loads on the internal combustion engine. This not only improves engine efficiency and thermal efficiency, enhancing output power, but also effectively protects the engine structure while maintaining high performance, extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Structure and working principle diagram of the present invention

[0045] In the figure: 1 exhaust duct; 2 cylinder head; 3 piston; 4 main combustion chamber; 5 electronic control unit; 6 cylinder pressure sensor; 7 drive motor; 8 pre-combustion chamber sealing block; 9 pre-combustion chamber throat slider; 10 spark plug; 11 pre-combustion chamber fuel nozzle; 12 pre-combustion chamber; 13 main combustion chamber fuel nozzle; 14 temperature sensor; 15 intake pressure sensor; 16 intake duct; 17 pressure reducer; 18 fuel bottle.

[0046] a. Speed signal; b. Load signal; c. Torque signal; d. Cylinder pressure signal; e. Drive motor position feedback signal; f. Drive motor control signal; g. Ignition signal; h. Pre-combustion chamber fuel nozzle signal; i. Main combustion chamber fuel nozzle signal; j. Intake pressure signal; k. Temperature signal; T. The point where the total flow area of the pre-combustion chamber nozzle is the largest; B. The point where the total flow area of the pre-combustion chamber nozzle is the smallest. DETAILED DESCRIPTION

[0047] The present invention will be further described below in conjunction with the accompanying drawings:

[0048] like Figure 1As shown, an internal combustion engine based on a variable pre-combustion chamber nozzle total flow area includes a cylinder head (2), a main combustion chamber (4), a piston (3), a cylinder pressure sensor (6) installed on the internal combustion engine body, an intake duct (16), an exhaust duct (1), and a pre-combustion chamber (12) installed on the cylinder head (2), characterized in that the throat of the pre-combustion chamber (12) is square, the front and rear walls are fixed, the left and right side walls are pre-combustion chamber throat sliders (9), and the drive motor (7) is installed in the pre-combustion chamber (12) The transition zone and the cylinder head (2) are provided with a slide rail on the drive motor (7). The pre-combustion chamber sealing block (9) is installed on the slide rail of the drive motor (7). The pre-combustion chamber sealing block (8) and the pre-combustion chamber throat slider (9) are rigidly connected. The pre-combustion chamber sealing block (8) and the pre-combustion chamber throat slider (9) can move left and right under the drive of the drive motor (7) to control the total flow area of the pre-combustion chamber nozzle. When the pre-combustion chamber throat slider (9) moves to T, the total nozzle area of the pre-combustion chamber is defined as S. max When the slider (9) of the throat of the pre-combustion chamber moves to B, the total nozzle area of the pre-combustion chamber is defined as S. min The spark plug (10) and the pre-combustion chamber fuel nozzle (11) are respectively installed on the top cover of the pre-combustion chamber (12); the fuel stored in the fuel bottle (18) is decompressed by the pressure reducer (17) and connected to the pre-combustion chamber fuel nozzle (11) and the main combustion chamber fuel nozzle (13) through pipelines; an intake pressure sensor (14) and a temperature sensor (15) are respectively installed on the exhaust duct (16).

[0049] The electronic control unit (5) obtains a rotation speed signal a by connecting or communicating with an existing rotation speed sensor in the internal combustion engine;

[0050] The electronic control unit (5) obtains the load signal b by connecting or communicating with an existing control handle or pedal in the internal combustion engine;

[0051] The electronic control unit (5) obtains an output torque signal c by connecting or communicating with an existing digital torque sensor in the internal combustion engine;

[0052] The electronic control unit (5) is connected to the cylinder pressure sensor (6) via a wire, and determines the combustion chamber pressure in the main combustion chamber (4) by receiving the cylinder pressure signal d;

[0053] The electronic control unit (5) is connected to the spark plug (10) via a wire and controls the spark plug (6) to spark by sending an ignition signal g;

[0054] The electronic control unit (5) is connected to the pre-combustion chamber fuel nozzle (11) through a wire, and controls the injection of the pre-combustion chamber fuel nozzle (16) by sending a pre-combustion chamber hydrogen nozzle control signal h;

[0055] The electronic control unit (5) is connected to the main combustion chamber fuel nozzle (13) through a wire, and controls the main combustion chamber fuel nozzle (13) to spray by sending a main combustion chamber hydrogen nozzle control signal i;

[0056] The electronic control unit (5) is connected to the four drive motors (7) via wires, and controls the movement of the pre-combustion chamber sealing block (8) on the slide rail of the drive motor (7) by sending a motion signal f from the drive motor (7). The electronic control unit (5) determines the actual position of the pre-combustion chamber sealing block (8) by receiving a position feedback signal e sent by the drive motor (7), thereby completing closed-loop control of the drive motor (7);

[0057] The electronic control unit (5) is connected to the temperature sensor (14) via a wire, and obtains the temperature of the fuel entering the main combustion chamber (2) by receiving the temperature signal k;

[0058] The electronic control unit (5) is connected to the intake pressure sensor (15) via a wire and obtains the pressure in the intake passage (15) by receiving the intake pressure signal j.

[0059] A method for controlling the total flow area of a controllable pre-combustion chamber nozzle hole comprises the following steps:

[0060] According to the actual effect of the total flow area of the nozzle holes of different pre-combustion chambers (12), a control method for the total flow area of the nozzle holes of a controllable pre-combustion chamber can be divided into a jet ignition combustion control method and a diffusion combustion control method, which are respectively:

[0061] 1) Jet ignition combustion control method

[0062] The electronic control unit (5) determines the working state of the internal combustion engine through the load signal b. When the load rate (L) is lower than 40% (the load rate refers to the ratio of the actual power received by the electronic control unit (5) at a certain speed to the maximum rated power at that speed), the electronic control unit (5) determines that the engine is in a low-load state and adopts the jet ignition combustion control method. At this time, the electronic control unit (5) calculates the hydrogen injection amount in each working cycle according to formula (1):

[0063]

[0064] In formula (1), T is the temperature of the fuel entering the main combustion chamber (4) obtained by the electronic control unit (5) according to the temperature signal k, N is the internal combustion engine speed obtained by the electronic control unit (5) according to the speed signal a, P is the intake pressure obtained by the electronic control unit (5) according to the intake pressure signal j, and A is the cross-sectional area of the hydrogen nozzle.

[0065] The electronic control unit (5) controls the injection of the pre-combustion chamber fuel nozzle (11) and the main combustion chamber fuel nozzle (13) by sending a pre-combustion chamber hydrogen nozzle control signal h and a main combustion chamber hydrogen nozzle control signal i. At this time, the amount of hydrogen injected into the pre-combustion chamber is Amount of hydrogen injected into the main combustion chamber

[0066] The electronic control unit (5) controls the displacement of the pre-combustion chamber throat slider (9) according to equation (2).

[0067]

[0068] In formula (2), S max is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the maximum throat diameter T., S min is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the minimum throat diameter B., and L is the load rate.

[0069] When the electronic control unit (5) controls the pre-combustion chamber sealing block (8) to move on the slide rail of the drive motor (7) by sending a motion signal f of the drive motor (7), the electronic control unit (5) determines the actual position of the slide rail of the drive motor (7) by receiving a slide rail position feedback signal e sent by the drive motor (7). If the relative error between the pre-combustion chamber sealing block (8) provided by the drive motor position feedback signal and the target control displacement exceeds 10%, the electronic control unit (5) determines that there is a fault in the system and immediately sends a motion signal f of the drive motor (7) to instruct the pre-combustion chamber sealing block (8) to return to the T position to ensure safe and stable operation of the engine.

[0070] The electronic control unit (5) sends an ignition signal i to control the ignition timing of the spark plug (13) to be 5° crank angle before the top dead center. At the same time, the electronic control unit (13) obtains the cylinder pressure p by receiving the cylinder pressure signal c, and further calculates the pressure increase rate dp / dCA.

[0071] If the maximum pressure increase rate dp / dCA of the cycle is not greater than 0.2 MPa at this time, the electronic control unit (5) keeps the hydrogen injection amount in the pre-combustion chamber and the main combustion chamber, the ignition angle, the pre-combustion chamber push rod and other parameters unchanged. If the maximum pressure increase rate dp / dCA is greater than 0.2 MPa at this time, the electronic control unit (5) sends an ignition signal i to control the spark plug (6) to delay the ignition angle by 1° crank angle, that is, the ignition angle at this time is 6° crank angle before top dead center, until the nth maximum pressure increase rate dp / dCA is not greater than 0.2 MPa, and the ignition angle at this time is (5+n)° crank angle before top dead center.

[0072] 2) Diffusion combustion control method

[0073] The electronic control unit (5) determines the working state of the internal combustion engine through the load signal b. When the load rate (L) is lower than 40% (the load rate refers to the ratio of the actual power received by the electronic control unit (5) at a certain speed to the maximum rated power at that speed), the electronic control unit (5) determines that the engine is in a low-load state and adopts the jet ignition combustion control method. At this time, the electronic control unit (5) calculates the hydrogen injection amount in each working cycle according to formula (1):

[0074]

[0075] In formula (1), T is the temperature of the fuel entering the main combustion chamber (4) obtained by the electronic control unit (5) according to the temperature signal k, N is the internal combustion engine speed obtained by the electronic control unit (5) according to the speed signal a, P is the intake pressure obtained by the electronic control unit (5) according to the intake pressure signal j, and A is the cross-sectional area of the hydrogen nozzle.

[0076] The electronic control unit (5) controls the injection of the pre-combustion chamber fuel nozzle (11) and the main combustion chamber fuel nozzle (13) by sending a pre-combustion chamber hydrogen nozzle control signal h and a main combustion chamber hydrogen nozzle control signal i. At this time, the amount of hydrogen injected into the pre-combustion chamber is Amount of hydrogen injected into the main combustion chamber

[0077] The electronic control unit (5) controls the displacement of the pre-combustion chamber throat slider (9) according to equation (2).

[0078]

[0079] In formula (2), S max is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the maximum throat diameter T., S min is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the minimum throat diameter B., and L is the load rate.

[0080] When the electronic control unit (5) controls the pre-combustion chamber sealing block (8) to move on the slide rail of the drive motor (7) by sending a motion signal f of the drive motor (7), the electronic control unit (5) determines the actual position of the slide rail of the drive motor (7) by receiving a slide rail position feedback signal e sent by the drive motor (7). If the relative error between the pre-combustion chamber sealing block (8) provided by the drive motor position feedback signal and the target control displacement exceeds 10%, the electronic control unit (5) determines that there is a fault in the system and immediately sends a motion signal f of the drive motor (7) to instruct the pre-combustion chamber sealing block (8) to return to the T position to ensure safe and stable operation of the engine.

[0081] The electronic control unit (5) sends an ignition signal i to control the ignition timing of the spark plug (13) to be 5° crank angle before the top dead center. At the same time, the electronic control unit (13) obtains the cylinder pressure p by receiving the cylinder pressure signal c, and further calculates the pressure increase rate dp / dCA.

[0082] If the maximum pressure increase rate dp / dCA of the cycle is not greater than 0.2 MPa at this time, the electronic control unit (5) keeps the hydrogen injection amount in the pre-combustion chamber and the main combustion chamber, the ignition angle, the pre-combustion chamber push rod and other parameters unchanged. If the maximum pressure increase rate dp / dCA is greater than 0.2 MPa at this time, the electronic control unit (5) sends an ignition signal i to control the spark plug (6) to delay the ignition angle by 1° crank angle, that is, the ignition angle at this time is 6° crank angle before top dead center, until the nth maximum pressure increase rate dp / dCA is not greater than 0.2 MPa, and the ignition angle at this time is (5+n)° crank angle before top dead center.

[0083] This embodiment carries out the following experiments on various working conditions:

[0084] The experimental engine is based on Figure 1 The internal combustion engine with controllable total flow area of the pre-combustion chamber nozzles was manufactured with a rated power of 4000kW and a rated power speed of 1800r / min. Experimental verification was carried out under two control modes:

[0085] (1) Jet ignition combustion experiment

[0086] The engine is running at 450r / min and 500kW. The electronic control unit (5) determines that the engine is in a low-load and low-speed state. The electronic control unit (5) controls the amount of hydrogen injected into the pre-combustion chamber (m PC ) Hydrogen injection volume in the main combustion chamber (m MC ) And by sending the driving motor control signal f, the pre-combustion chamber sealing block (8) drives the pre-combustion chamber throat slider (9) to move. At this time, the total flow area of the pre-combustion chamber is S=0.9375S min +0.0625S max The electronic control unit (5) receives the cylinder pressure signal d from the cylinder pressure sensor (6) and obtains a maximum pressure increase rate of 0.3 MPa / °CA. Based on the above signal, the electronic control unit (5) controls the spark plug (10) to delay the ignition timing by issuing an ignition signal g while maintaining the hydrogen injection amount in the pre-combustion chamber and the main combustion chamber. The maximum pressure increase rate is finally measured to be 0.2 MPa / °CA, with an effective efficiency of 45.9%.

[0087] (2) Diffusion combustion experiment

[0088] The engine is running at 1440r / min, 3200kW. The electronic control unit (5) determines that the engine is in a low load and low speed state. The electronic control unit (5) controls the hydrogen injection amount (m PC ) Hydrogen injection volume in the main combustion chamber (m MC ) And by sending the driving motor control signal f, the pre-combustion chamber sealing block (8) drives the pre-combustion chamber throat slider (9) to move. At this time, the total flow area of the pre-combustion chamber is S=0.2667S min +0.7333S max The electronic control unit (5) receives the cylinder pressure signal d from the cylinder pressure sensor (6) and obtains a maximum pressure increase rate of 0.3 MPa / °CA. Based on the above signal, the electronic control unit (5) controls the spark plug (10) to delay the ignition timing by issuing an ignition signal g while maintaining the hydrogen injection amount in the pre-combustion chamber and the main combustion chamber unchanged. The maximum pressure increase rate is finally measured to be 0.2 MPa / °CA, with an effective efficiency of 46.6%.

[0089] During the above-mentioned experiments, no abnormal combustion problems such as backfire and detonation were observed. The results show that the heavy-duty engine and control method with a variable total flow area of the pre-combustion chamber nozzle provided by the present invention can effectively improve the power density of the heavy-duty hydrogen internal combustion engine and expand its high-efficiency and stable operating range.

[0090] Any matters not described in the present invention are applicable to the prior art.

Claims

1. An internal combustion engine based on a variable pre-combustion chamber nozzle total flow area comprises a cylinder head (2) mounted on the internal combustion engine body, a main combustion chamber (4), a piston (3), a cylinder pressure sensor (6), an intake duct (16), an exhaust duct (1), and a pre-combustion chamber (12) mounted on the cylinder head (2), characterized in that: The throat of the precombustion chamber (12) is square, the front and rear walls are fixed, and the left and right side walls are precombustion chamber throat sliders (9). The driving motor (7) is installed on the transition zone of the precombustion chamber (12) and the cylinder head (2). The driving motor (7) is provided with a slide rail, and the precombustion chamber sealing block (8) is installed on the slide rail of the driving motor (7). The precombustion chamber sealing block (8) and the precombustion chamber throat slider (9) are rigidly connected. The precombustion chamber sealing block (8) and the precombustion chamber throat slider (9) can move left and right under the drive of the driving motor (7) to control the total flow area of the precombustion chamber nozzle. T represents the maximum throat diameter that the driving motor (7) can reach by driving the precombustion chamber throat slider (9) through the precombustion chamber sealing block (8). When the precombustion chamber throat slider (9) moves to T, the total nozzle area of the precombustion chamber is defined as S. max , B. represents the minimum throat diameter that can be reached by the driving motor (7) through the pre-combustion chamber sealing block (8) to drive the pre-combustion chamber throat slider (9). When the pre-combustion chamber throat slider (9) moves to B., the total nozzle area of the pre-combustion chamber is defined as S min The spark plug (10) and the pre-combustion chamber fuel nozzle (11) are respectively installed on the top cover of the pre-combustion chamber (12); the fuel stored in the fuel bottle (18) is decompressed by the pressure reducer (17) and connected to the pre-combustion chamber fuel nozzle (11) and the main combustion chamber fuel nozzle (13) through pipelines; an intake pressure sensor (14) and a temperature sensor (15) are respectively installed on the exhaust duct (16); The electronic control unit (5) obtains a rotation speed signal a by connecting or communicating with an existing rotation speed sensor in the internal combustion engine; The electronic control unit (5) obtains the load signal b by connecting or communicating with an existing control handle or pedal in the internal combustion engine; The electronic control unit (5) obtains an output torque signal c by connecting or communicating with an existing digital torque sensor in the internal combustion engine; The electronic control unit (5) is connected to the cylinder pressure sensor (6) via a wire, and determines the combustion chamber pressure in the main combustion chamber (4) by receiving the cylinder pressure signal d; The electronic control unit (5) is connected to the spark plug (10) via a wire and controls the spark plug (6) to spark by sending an ignition signal g; The electronic control unit (5) is connected to the pre-combustion chamber fuel nozzle (11) through a wire, and controls the injection of the pre-combustion chamber fuel nozzle (16) by sending a pre-combustion chamber hydrogen nozzle control signal h; The electronic control unit (5) is connected to the main combustion chamber fuel nozzle (13) through a wire, and controls the main combustion chamber fuel nozzle (13) to spray by sending a main combustion chamber hydrogen nozzle control signal i; The electronic control unit (5) is connected to the four drive motors (7) via wires, and controls the movement of the pre-combustion chamber sealing block (8) on the slide rail of the drive motor (7) by sending a motion signal f from the drive motor (7). The electronic control unit (5) determines the actual position of the pre-combustion chamber sealing block (8) by receiving a position feedback signal e sent by the drive motor (7), thereby completing closed-loop control of the drive motor (7); The electronic control unit (5) is connected to the temperature sensor (14) via a wire, and obtains the temperature of the fuel entering the main combustion chamber (2) by receiving the temperature signal k; The electronic control unit (5) is connected to the intake pressure sensor (15) via a wire and obtains the pressure in the intake passage (15) by receiving the intake pressure signal j.

2. A method for using an internal combustion engine according to claim 1, characterized in that: According to the actual effect of the total flow area of different pre-combustion chambers (12), it is divided into a jet ignition combustion control mode and a diffusion combustion control mode, which are respectively: 1) Jet ignition combustion control method The electronic control unit (5) determines the working state of the internal combustion engine through the load signal b; when the load rate (L) is lower than 40% (the load rate refers to the ratio of the actual power received by the electronic control unit (5) at a certain speed to the maximum rated power at the speed), the electronic control unit (5) determines that the engine is in a low-load state and adopts the jet ignition combustion control mode; at this time, the electronic control unit (5) calculates the hydrogen injection amount in each working cycle according to formula (1): In formula (1), T is the temperature of the gas entering the main combustion chamber (4) obtained by the electronic control unit (5) according to the temperature signal k, N is the speed of the internal combustion engine obtained by the electronic control unit (5) according to the speed signal a, P is the intake pressure obtained by the electronic control unit (5) according to the intake pressure signal j, and A is the cross-sectional area of the hydrogen nozzle; The electronic control unit (5) controls the injection of the pre-combustion chamber fuel nozzle (11) and the main combustion chamber fuel nozzle (13) by sending a pre-combustion chamber hydrogen nozzle control signal h and a main combustion chamber hydrogen nozzle control signal i. At this time, the amount of hydrogen injected into the pre-combustion chamber is Amount of hydrogen injected into the main combustion chamber The electronic control unit (5) controls the displacement of the pre-combustion chamber throat slider (9) according to formula (2); In formula (2), S max is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the maximum throat diameter T., S min is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the minimum throat diameter B., and L is the load rate; When the electronic control unit (5) controls the pre-combustion chamber sealing block (8) to move on the slide rail of the drive motor (7) by sending a motion signal f of the drive motor (7), the electronic control unit (5) determines the actual position of the slide rail of the drive motor (7) by receiving a slide rail position feedback signal e sent by the drive motor (7); if the relative error between the pre-combustion chamber sealing block (8) provided by the drive motor position feedback signal and the target control displacement exceeds 10%, the electronic control unit (5) determines that there is a fault in the system and immediately sends a motion signal f of the drive motor (7) to instruct the pre-combustion chamber sealing block (8) to return to the T position, so as to ensure the safe and stable operation of the engine; The electronic control unit (5) sends an ignition signal i to control the ignition timing of the spark plug (13) to be 5° crank angle before the top dead center. At the same time, the electronic control unit (13) obtains the cylinder pressure p by receiving the cylinder pressure signal c, and further calculates the pressure increase rate dp / dCA; If the maximum cycle pressure rise rate dp / dCA is not greater than 0.2 MPa, the electronic control unit (5) keeps the hydrogen injection amount, ignition angle, pre-combustion chamber push rod and other parameters in the pre-combustion chamber and the main combustion chamber unchanged; If the maximum pressure rise rate dp / dCA is greater than 0.2 MPa at this time, the electronic control unit (5) sends an ignition signal i to control the spark plug (6) to delay the ignition angle by 1 crank angle, i.e., the ignition angle at this time is 6 crank angles before top dead center, while maintaining the hydrogen injection amount in the pre-combustion chamber and the main combustion chamber unchanged, until the nth maximum pressure rise rate dp / dCA is not greater than 0.2 MPa, and the ignition angle at this time is (5+n) crank angles before top dead center; 2) Diffusion combustion control method The electronic control unit (5) determines the working state of the internal combustion engine through the load signal b; when the load rate (L) is lower than 40% (the load rate refers to the ratio of the actual power received by the electronic control unit (5) at a certain speed to the maximum rated power at the speed), the electronic control unit (5) determines that the engine is in a low-load state and adopts the jet ignition combustion control mode; at this time, the electronic control unit (5) calculates the hydrogen injection amount in each working cycle according to formula (1): In formula (1), T is the temperature of the gas entering the main combustion chamber (4) obtained by the electronic control unit (5) according to the temperature signal k, N is the speed of the internal combustion engine obtained by the electronic control unit (5) according to the speed signal a, P is the intake pressure obtained by the electronic control unit (5) according to the intake pressure signal j, and A is the cross-sectional area of the hydrogen nozzle; The electronic control unit (5) controls the injection of the pre-combustion chamber fuel nozzle (11) and the main combustion chamber fuel nozzle (13) by sending a pre-combustion chamber hydrogen nozzle control signal h and a main combustion chamber hydrogen nozzle control signal i. At this time, the amount of hydrogen injected into the pre-combustion chamber is Amount of hydrogen injected into the main combustion chamber The electronic control unit (5) controls the displacement of the pre-combustion chamber throat slider (9) according to formula (2); In formula (2), S max is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the maximum throat diameter T., S min is the total nozzle area of the pre-combustion chamber when the pre-combustion chamber throat slider (9) moves to the minimum throat diameter B., and L is the load rate; When the electronic control unit (5) controls the pre-combustion chamber sealing block (8) to move on the slide rail of the drive motor (7) by sending a motion signal f of the drive motor (7), the electronic control unit (5) determines the actual position of the slide rail of the drive motor (7) by receiving a slide rail position feedback signal e sent by the drive motor (7); if the relative error between the pre-combustion chamber sealing block (8) provided by the drive motor position feedback signal and the target control displacement exceeds 10%, the electronic control unit (5) determines that there is a fault in the system and immediately sends a motion signal f of the drive motor (7) to instruct the pre-combustion chamber sealing block (8) to return to the T position, so as to ensure the safe and stable operation of the engine; The electronic control unit (5) sends an ignition signal i to control the ignition timing of the spark plug (13) to be 5° crank angle before the top dead center. At the same time, the electronic control unit (13) obtains the cylinder pressure p by receiving the cylinder pressure signal c, and further calculates the pressure increase rate dp / dCA; If the maximum cycle pressure rise rate dp / dCA is not greater than 0.2 MPa, the electronic control unit (5) keeps the hydrogen injection amount, ignition angle, pre-combustion chamber push rod and other parameters in the pre-combustion chamber and the main combustion chamber unchanged; If the maximum pressure rise rate dp / dCA is greater than 0.2 MPa at this time, the electronic control unit (5) sends an ignition signal i to control the spark plug (6) to delay the ignition angle by 1 crank angle, i.e., the ignition angle at this time is 6 crank angles before top dead center, while maintaining the hydrogen injection amount in the pre-combustion chamber and the main combustion chamber unchanged, until the nth maximum pressure rise rate dp / dCA is not greater than 0.2 MPa, and the ignition angle at this time is (5+n) crank angles before top dead center.

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