Hydrogen-oxygen internal combustion engine capable of controlling volume of pre-combustion chamber and control method

Abstract

The invention provides a hydrogen-oxygen internal combustion engine capable of controlling the volume of a pre-combustion chamber and a control method, particularly relates to a device for changing the volume of the pre-combustion chamber by controlling the position of a top cover of the pre-combustion chamber and a control strategy, and belongs to the field of hydrogen-oxygen internal combustion engines. The oxyhydrogen internal combustion engine is characterized in that a sliding pre-combustion chamber top cover (8) based on the pre-combustion chamber is additionally arranged, and by changing the position of the sliding pre-combustion chamber top cover (8), the volume of the pre-combustion chamber is changed in real time in the variable working condition operation process of the internal combustion engine; abnormal combustion problems such as unstable combustion, even fire catching and the like in the pre-combustion chamber due to the fact that the equivalence ratio of the pre-combustion chamber exceeds the hydrogen-oxygen combustible limit are solved, meanwhile, the problem that the pre-combustion chamber is poor in ventilation effect is remarkably solved, and efficient and stable operation of the hydrogen-oxygen internal combustion engine is achieved. The lightweight design of the structure also meets the requirements of a spaceflight system on harsh quality constraints.

Description

Technical Field

[0001] The present invention provides a hydrogen-oxygen internal combustion engine with controllable pre-combustion chamber volume and a control method, specifically relating to a device and a control strategy for controlling the position of a pre-combustion chamber top cover to change the pre-combustion chamber volume, and belongs to the field of hydrogen-oxygen internal combustion engines. Background Art

[0002] During the operation of aerospace propulsion systems, the evaporation of liquid hydrogen and liquid oxygen increases the pressure in the fuel tanks. The evaporated gases need to be released to ensure system safety, but this can lead to fuel loss and affect the execution of long-duration space missions. To address this issue, hydrogen-oxygen internal combustion engines are used to generate auxiliary power to support the operation of spacecraft instruments and communications equipment, thereby ensuring the long-term operation of space missions while avoiding energy waste.

[0003] In order to prevent the combustion of a mixture of pure hydrogen and pure oxygen, which would generate high pressure and temperature in the cylinder and damage the engine structure, existing hydrogen-oxygen internal combustion engines use the existing technology to inject hydrogen into the intake duct and inject oxygen from the nozzle in the pre-combustion chamber. The diffusion injection is guided by the pre-combustion chamber, which effectively avoids damage to the internal combustion engine caused by excessive thermal and mechanical loads, and avoids abnormal combustion problems such as detonation and backfire caused by the early premixing of hydrogen and oxygen, thereby achieving stable and controllable combustion.

[0004] A major challenge facing hydrogen-oxygen internal combustion engines is that, under a hydrogen-rich combustion strategy, the engine load output is controlled by varying the oxygen injection rate in the precombustion chamber. However, during cold start, idling, and low-load to high-load cycles, the precombustion chamber oxygen injection rate varies significantly. This can lead to combustion instability and even misfires in the precombustion chamber due to the equivalence ratio exceeding the hydrogen-oxygen rich limit at low speeds and low loads, and exceeding the hydrogen-oxygen lean limit at high speeds and high loads. Using precombustion chambers of varying volumes could address these issues, but existing precombustion chambers are all fixed in volume. While installing precombustion chambers of varying volumes on the engine and varying the initial hydrogen volume and equivalence ratio within the precombustion chamber could achieve stable engine operation, using a smaller precombustion chamber at low speeds and low loads and a larger precombustion chamber at high speeds and high loads, this approach significantly increases the engine's complexity. Furthermore, given the stringent quality requirements of aerospace systems, this approach is difficult to apply to hydrogen-oxygen internal combustion engines in aerospace propulsion systems.

[0005] Another problem faced by the pre-combustion chamber is poor air exchange efficiency, for which no effective solution has yet been found. Summary of the Invention

[0006] In view of the fact that the volume of the pre-combustion chamber of an existing internal combustion engine is difficult to change in real time during operation, the present invention provides an internal combustion engine with controllable pre-combustion chamber volume and a control method.

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

[0008] An internal combustion engine based on a variable volume pre-combustion chamber comprises a cylinder head (1), a piston (11), a temperature and pressure sensor (4) mounted on an internal combustion engine body, an intake duct (14), an exhaust duct (3), and a pre-combustion chamber (5) mounted on the cylinder head (1), a hydrogen flow sensor (17) and a throttle valve (18) mounted on the intake duct (14), and is characterized in that a sliding pre-combustion chamber top cover (8) is mounted in the pre-combustion chamber (5), and a sealing member is provided between the sliding pre-combustion chamber top cover (8) and the inner wall of the pre-combustion chamber. The ring (7) is provided, and the pre-combustion chamber push rod (10) is connected to the sliding pre-combustion chamber top cover (8). The pre-combustion chamber push rod (10) passes through the pre-combustion chamber push rod control valve (9). The pre-combustion chamber push rod control valve (9) controls the up and down displacement of the pre-combustion chamber push rod (10). The spark plug (6) and the pre-combustion chamber oxygen nozzle (12) are respectively installed on the sliding pre-combustion chamber top cover (8). The oxygen stored in the oxygen cylinder (15) is decompressed by the pressure reducing valve (13) and is flexibly connected to the pre-combustion chamber oxygen nozzle (12) through a pipeline.

[0009] The electronic control unit (16) obtains a speed signal a by connecting to an existing speed sensor in the internal combustion engine;

[0010] The electronic control unit (16) obtains a torque signal b by connecting to an existing control handle or pedal in the internal combustion engine;

[0011] The electronic control unit (16) is connected to the temperature and pressure sensor (4) via a wire, and obtains the pressure and temperature in the pre-combustion chamber (5) by receiving the temperature and pressure signal c;

[0012] The electronic control unit (16) is connected to the spark plug (6) via a wire and controls the spark plug (6) to spark by sending an ignition signal d;

[0013] The electronic control unit (16) is connected to the pre-combustion chamber push rod control valve (9) through a wire, and controls the movement of the pre-combustion chamber push rod (10) by receiving a pre-combustion chamber push rod position feedback signal e and sending a pre-combustion chamber push rod control signal f;

[0014] The electronic control unit (16) is connected to the pre-combustion chamber oxygen nozzle (12) through a wire, and controls the pre-combustion chamber oxygen nozzle (12) to spray by sending a spray signal g;

[0015] The electronic control unit (16) is connected to the hydrogen flow sensor (17) via a wire, and obtains the mass flow of hydrogen entering the cylinder by receiving the hydrogen flow signal h;

[0016] The electronic control unit (16) is connected to the throttle valve (18) via a wire and controls the opening angle of the throttle valve (18) by sending a throttle valve control signal q.

[0017] A hydrogen-oxygen internal combustion engine based on a controllable pre-combustion chamber volume and a control method thereof, comprising the following steps:

[0018] The electronic control unit (16) sends a throttle control signal q to open the throttle (18) to allow hydrogen to enter the cylinder, and the hydrogen flow rate is set to The electronic control unit (16) receives the speed signal a, the load signal b, and the temperature and pressure signal c to obtain the actual speed (N) and actual torque (T A ), the pressure (P) and temperature (T) in the pre-combustion chamber. The electronic control unit (16) calculates the oxygen injection amount per cycle according to formula (1):

[0019]

[0020] Where: T B - target torque, η - theoretical energy conversion efficiency of the internal combustion engine, approximately 0.3, q - lower calorific value of hydrogen, α - ratio of the pre-combustion chamber volume to the total combustion chamber volume, β - theoretically derived correction factor, approximately 1.15;

[0021] The electronic control unit (16) calculates the excess air coefficient λ in the pre-combustion chamber according to formula (2): pc :

[0022]

[0023] Where: V pc -precombustion chamber volume; R-gas constant; - molar mass of hydrogen;

[0024] When the λ in the precombustion chamber pc When the value of 0.8≤λpc≤1.2 is not satisfied, the electronic control unit (16) sends a pre-combustion chamber push rod control signal f to control the pre-combustion chamber push rod (10) to drive the sliding pre-combustion chamber top cover (8) to adjust the volume V of the pre-combustion chamber (5). pc The electronic control unit (16) calculates the excess air coefficient λ after the pre-combustion chamber volume changes according to formula (3): pc·δ :

[0025]

[0026] Where: V pc·δ -Adjusted pre-chamber volume; T δ - The temperature in the pre-combustion chamber after adjustment; P δ -Adjust the pressure in the precombustion chamber; α δ - Ratio of adjusted pre-chamber volume to total combustion chamber volume;

[0027] When the actual torque of the internal combustion engine (T A ) changes to the target torque (T B)hour,

[0028] Under this condition, the electronic control unit (16) controls the pre-combustion chamber oxygen nozzle (12) to spray oxygen in an amount of The electronic control unit (16) calculates the λ in the pre-combustion chamber after the oxygen is injected pc , if 0.8≤λ pc ≤1.2, the electronic control unit (16) only receives the pre-combustion chamber push rod position feedback signal e marked push rod position HT; when λ pc <0.8, the electronic control unit (16) controls the pre-combustion chamber push rod control valve (9) by sending a pre-combustion chamber push rod control signal f to drive the pre-combustion chamber push rod (10) to drive the sliding pre-combustion chamber top cover (8) to move synchronously to the min position, each time moving 1mm until λ pc·δ ≥0.8 and then stops moving, the electronic control unit (16) receives the pre-combustion chamber push rod position feedback signal e and marks the push rod position HT; if λ pc >1.2, the electronic control unit (16) controls the pre-combustion chamber push rod control valve (9) by sending a pre-combustion chamber push rod control signal f to drive the pre-combustion chamber push rod to drive the sliding pre-combustion chamber top cover (8) to move synchronously to the max position, each time moving 1mm until λ pc·δ ≤1.2 and stops moving. The electronic control unit (16) receives the pre-combustion chamber push rod position feedback signal e and marks the push rod position HT.

[0029] During the exhaust phase, the electronic control unit (16) controls the pre-combustion chamber push rod control valve (9) by sending a pre-combustion chamber push rod control signal f to drive the pre-combustion chamber push rod (10) and the sliding pre-combustion chamber top cover (8) to move downward synchronously to the minimum pre-combustion chamber volume min; during the intake phase, the electronic control unit (16) controls the pre-combustion chamber push rod (10) controlled by the pre-combustion chamber push rod control valve (9) to return to the previous position HT by sending a pre-combustion chamber push rod control signal f.

[0030] In the process of the electronic control unit (16) sending a pre-combustion chamber push rod control signal f to control the pre-combustion chamber push rod (10) controlled by the pre-combustion chamber push rod control valve (9), the electronic control unit (16) receives the pre-combustion chamber push rod position feedback signal e sent from the pre-combustion chamber push rod control valve (9). When the relative error between the displacement of the pre-combustion chamber push rod (10) provided by the pre-combustion chamber push rod position feedback signal e and the target is greater than 5%, the electronic control unit (16) determines that the system has failed; when the position of the pre-combustion chamber push rod (10) provided by the pre-combustion chamber push rod position feedback signal e exceeds the minimum pre-combustion chamber volume min and the maximum pre-combustion chamber volume max, the electronic control unit (16) determines that the system has failed; when a system failure occurs, the electronic control unit (16) immediately sends a pre-combustion chamber push rod control signal f to control the pre-combustion chamber push rod control valve (9) to drive the pre-combustion chamber push rod (10) back to the middle of the pre-combustion chamber volume m to ensure the safe operation of the internal combustion engine.

[0031] The beneficial effect of the present invention is that it addresses the problem that the volume of a traditional precombustion chamber is difficult to adjust in real time according to the variable working conditions of an internal combustion engine, and faces problems such as unstable combustion and even misfires. The present invention provides a hydrogen-oxygen internal combustion engine with controllable precombustion chamber volume and a control method. The device adopts a movable precombustion chamber top cover, which realizes the real-time change of the precombustion chamber volume during the operation of the internal combustion engine under variable working conditions, eliminates abnormal combustion problems such as unstable combustion and even misfires in the precombustion chamber caused by the equivalence ratio of the precombustion chamber exceeding the hydrogen-oxygen flammability limit, and significantly improves the problem of poor ventilation effect in the precombustion chamber, realizing efficient and stable operation of the hydrogen-oxygen internal combustion engine. The lightweight design of the structure also meets the stringent quality constraints of the aerospace system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Structure and working principle diagram of the present invention

[0033] In the figure: 1 cylinder head; 2 main combustion chamber; 3 exhaust duct; 4 temperature and pressure sensor; 5 pre-combustion chamber; 6 spark plug; 7 sealing ring; 8 sliding pre-combustion chamber top cover; 9 pre-combustion chamber push rod control valve; 10 pre-combustion chamber push rod; 11 piston; 12 pre-combustion chamber oxygen nozzle; 13 pressure reducing valve; 14 intake duct; 15 oxygen cylinder; 16 electronic control unit; 17 hydrogen flow sensor; 18 throttle valve;

[0034] a. Speed signal; b. Torque signal; c. Temperature and pressure signal; d. Ignition signal; e. Pre-combustion chamber push rod position feedback signal; f. Pre-combustion chamber push rod control signal; g. Injection signal; h. Hydrogen flow signal; q. Throttle control signal; min. Minimum pre-combustion chamber volume; m. Middle pre-combustion chamber volume; max. Maximum pre-combustion chamber volume.

[0035] Specific implementation measures

[0036] The present invention is further described below with reference to the accompanying drawings, but this is not intended to limit the scope of protection of this application.

[0037] like Figure 1 As shown, an internal combustion engine based on a variable volume pre-combustion chamber comprises a cylinder head (1), a piston (11), a temperature and pressure sensor (4) mounted on the internal combustion engine body, an intake duct (14), an exhaust duct (3), and a pre-combustion chamber (5) mounted on the cylinder head (1), a hydrogen flow sensor (17) and a throttle valve (18) are respectively mounted on the intake duct (14), and is characterized in that a sliding pre-combustion chamber top cover (8) is mounted in the pre-combustion chamber (5), and a pre-combustion chamber inner wall is provided between the sliding pre-combustion chamber top cover (8) and the pre-combustion chamber inner wall. A sealing ring (7) and a pre-combustion chamber push rod (10) are connected to a sliding pre-combustion chamber top cover (8). The pre-combustion chamber push rod (10) passes through a pre-combustion chamber push rod control valve (9). The pre-combustion chamber push rod control valve (9) controls the up and down displacement of the pre-combustion chamber push rod (10). A spark plug (6) and a pre-combustion chamber oxygen nozzle (12) are respectively installed on the sliding pre-combustion chamber top cover (8). Oxygen stored in an oxygen cylinder (15) is decompressed by a pressure reducing valve (13) and is flexibly connected to the pre-combustion chamber oxygen nozzle (12) through a pipeline.

[0038] The electronic control unit (16) obtains a speed signal a by connecting to an existing speed sensor in the internal combustion engine;

[0039] The electronic control unit (16) obtains a torque signal b by connecting to an existing control handle or pedal in the internal combustion engine;

[0040] The electronic control unit (16) is connected to the temperature and pressure sensor (4) via a wire, and obtains the pressure and temperature in the pre-combustion chamber (5) by receiving the temperature and pressure signal c;

[0041] The electronic control unit (16) is connected to the spark plug (6) via a wire and controls the spark plug (6) to spark by sending an ignition signal d;

[0042] The electronic control unit (16) is connected to the pre-combustion chamber push rod control valve (9) through a wire, and controls the movement of the pre-combustion chamber push rod (10) by receiving a pre-combustion chamber push rod position feedback signal e and sending a pre-combustion chamber push rod control signal f;

[0043] The electronic control unit (16) is connected to the pre-combustion chamber oxygen nozzle (12) through a wire, and controls the pre-combustion chamber oxygen nozzle (12) to spray by sending a spray signal g;

[0044] The electronic control unit (16) is connected to the hydrogen flow sensor (17) via a wire, and obtains the mass flow of hydrogen entering the cylinder by receiving the hydrogen flow signal h;

[0045] The electronic control unit (16) is connected to the throttle valve (18) via a wire and controls the opening angle of the throttle valve (18) by sending a throttle valve control signal q.

[0046] A hydrogen-oxygen internal combustion engine based on a controllable pre-combustion chamber volume and a control method thereof, comprising the following steps:

[0047] The electronic control unit (16) sends a throttle control signal q to open the throttle (18) to allow hydrogen to enter the cylinder, and the hydrogen flow rate is set to The electronic control unit (16) receives the speed signal a, the load signal b, and the temperature and pressure signal c to obtain the actual speed (N) and actual torque (T A ), the pressure (P) and temperature (T) in the pre-combustion chamber. The electronic control unit (16) calculates the oxygen injection amount per cycle according to formula (1):

[0048]

[0049] Where: T B - target torque, η - theoretical energy conversion efficiency of the internal combustion engine, approximately 0.3, q - lower calorific value of hydrogen, α - ratio of the pre-combustion chamber volume to the total combustion chamber volume, β - theoretically derived correction factor, approximately 1.15;

[0050] The electronic control unit (16) calculates the excess air coefficient λ in the pre-combustion chamber according to formula (2): pc :

[0051]

[0052] Where: V pc -precombustion chamber volume; R-gas constant; - molar mass of hydrogen;

[0053] When the λ in the precombustion chamber pc When the value of 0.8≤λpc≤1.2 is not satisfied, the electronic control unit (16) sends a pre-combustion chamber push rod control signal f to control the pre-combustion chamber push rod (10) to drive the sliding pre-combustion chamber top cover (8) to adjust the volume V of the pre-combustion chamber (5). pc The electronic control unit (16) calculates the excess air coefficient λ after the pre-combustion chamber volume changes according to formula (3): pc·δ :

[0054]

[0055] Where: V pc·δ -Adjusted pre-chamber volume; T δ - The temperature in the pre-combustion chamber after adjustment; P δ -Adjust the pressure in the precombustion chamber; α δ- Ratio of adjusted pre-chamber volume to total combustion chamber volume;

[0056] When the actual torque of the internal combustion engine (T A ) changes to the target torque (T B )hour,

[0057] Under this condition, the electronic control unit (16) controls the pre-combustion chamber oxygen nozzle (12) to spray oxygen in an amount of The electronic control unit (16) calculates the λ in the pre-combustion chamber after the oxygen is injected pc , if 0.8≤λ pc ≤1.2, the electronic control unit (16) only receives the pre-combustion chamber push rod position feedback signal e marked push rod position HT; when λ pc <0.8, the electronic control unit (16) controls the pre-combustion chamber push rod control valve (9) by sending a pre-combustion chamber push rod control signal f to drive the pre-combustion chamber push rod (10) to drive the sliding pre-combustion chamber top cover (8) to move synchronously to the min position, each time moving 1mm until λ pc·δ ≥0.8 and then stops moving, the electronic control unit (16) receives the pre-combustion chamber push rod position feedback signal e and marks the push rod position HT; if λ pc >1.2, the electronic control unit (16) controls the pre-combustion chamber push rod control valve (9) by sending a pre-combustion chamber push rod control signal f to drive the pre-combustion chamber push rod to drive the sliding pre-combustion chamber top cover (8) to move synchronously to the max position, each time moving 1mm until λ pc·δ ≤1.2 and stops moving. The electronic control unit (16) receives the pre-combustion chamber push rod position feedback signal e and marks the push rod position HT.

[0058] During the exhaust phase, the electronic control unit (16) controls the pre-combustion chamber push rod control valve (9) by sending a pre-combustion chamber push rod control signal f to drive the pre-combustion chamber push rod (10) and the sliding pre-combustion chamber top cover (8) to move downward synchronously to the minimum pre-combustion chamber volume min; during the intake phase, the electronic control unit (16) controls the pre-combustion chamber push rod (10) controlled by the pre-combustion chamber push rod control valve (9) to return to the previous position HT by sending a pre-combustion chamber push rod control signal f.

[0059] In the process of the electronic control unit (16) sending a pre-combustion chamber push rod control signal f to control the pre-combustion chamber push rod (10) controlled by the pre-combustion chamber push rod control valve (9), the electronic control unit (16) receives the pre-combustion chamber push rod position feedback signal e sent from the pre-combustion chamber push rod control valve (9). When the relative error between the displacement of the pre-combustion chamber push rod (10) provided by the pre-combustion chamber push rod position feedback signal e and the target is greater than 5%, the electronic control unit (16) determines that the system has failed; when the position of the pre-combustion chamber push rod (10) provided by the pre-combustion chamber push rod position feedback signal e exceeds the minimum pre-combustion chamber volume min and the maximum pre-combustion chamber volume max, the electronic control unit (16) determines that the system has failed; when a system failure occurs, the electronic control unit (16) immediately sends a pre-combustion chamber push rod control signal f to control the pre-combustion chamber push rod control valve (9) to drive the pre-combustion chamber push rod (10) back to the middle of the pre-combustion chamber volume m to ensure the safe operation of the internal combustion engine.

[0060] This embodiment carries out the following experiments on various working conditions:

[0061] The experimental internal combustion engine is based on Figure 1 The oxyhydrogen internal combustion engine with controllable pre-combustion chamber volume was tested on a bench. The engine is a single-cylinder two-stroke reciprocating engine with a speed of 3000-4000RPM, an average power of 2kW, a maximum power of 3kW, and a main combustion chamber volume of 0.00446m 3 , the volume of the pre-combustion chamber varies from 0.000046 to 0.003m 3 During the experiment, the target torque of the internal combustion engine is controlled by connecting the crankshaft of the internal combustion engine to the dynamometer. The digital torque sensor is directly installed on the output shaft of the internal combustion engine to measure the output torque. The speed, cylinder pressure and other data are read through the calibration software of the electronic control unit (16) to carry out experimental verification of the control method.

[0062] The basic operating conditions of the hydrogen-oxygen internal combustion engine are set as follows: speed 3000RPM, initial volume of pre-combustion chamber 0.003m 3 , actual torque 6Nm, target torque (T B )9Nm;

[0063] The electronic control unit (16) sends a throttle control signal q to open the throttle (18) to allow hydrogen to enter the cylinder, and the hydrogen flow rate is set to The electronic control unit (16) receives data from the communication calibration software and sends an injection signal g to control the pre-combustion chamber oxygen nozzle (12) to inject oxygen of mass At this time, the electronic control unit (16) calculates λ pc<0.8, the electronic control unit (16) sends a pre-combustion chamber push rod control signal f to control the pre-combustion chamber push rod control valve (9) to drive the pre-combustion chamber push rod (10) to drive the sliding pre-combustion chamber top cover (8) to move synchronously to the min position, each time moving 1mm, so that the pre-combustion chamber volume is reduced to 0.0028m 3 ,λ pc·δ >0.8, the pre-combustion chamber is successfully ignited, the electronic control unit (16) receives the pre-combustion chamber push rod position feedback signal e and marks the push rod position HT, the electronic control unit (16) detects that the output torque is consistent with the target torque, and the electronic control unit (16) detects that the peak pressure in the cylinder is 8.4MPa at 16.8°CA at the top dead center. The test results show that the effective thermal efficiency of the internal combustion engine is relatively improved by 6.8%.

[0064] During the exhaust phase, the electronic control unit (16) sends a pre-combustion chamber push rod control signal f so that the pre-combustion chamber push rod (10) controlled by the pre-combustion chamber push rod control valve (9) drives the sliding pre-combustion chamber top cover (8) to move downward to the minimum pre-combustion chamber volume min; during the intake phase, the electronic control unit (16) sends a pre-combustion chamber push rod control signal f so that the pre-combustion chamber push rod (10) controlled by the pre-combustion chamber push rod control valve (9) drives the sliding pre-combustion chamber top cover (8) to return to the previous position HT.

[0065] During the above-mentioned experiment, no abnormal combustion problems such as unstable combustion or even misfire occurred. The experimental results show that the use of a hydrogen-oxygen internal combustion engine and a control method based on a controllable pre-combustion chamber volume provided by the present invention can improve the effective power of the hydrogen-oxygen internal combustion engine and the ventilation effect of the pre-combustion chamber, reduce its misfire frequency, and make the operation more stable and energy-saving.

[0066] Any matters not described in the present invention are applicable to the prior art.

Claims

1. An internal combustion engine based on a variable volume pre-combustion chamber, comprising a cylinder head (1), a piston (11), and a temperature and pressure sensor (4) mounted on an internal combustion engine body, an intake duct (14), an exhaust duct (3), and a pre-combustion chamber (5) mounted on the cylinder head (1), a hydrogen flow sensor (17) and a throttle valve (18) mounted on the intake duct (14), and characterized in that: A sliding pre-combustion chamber top cover (8) is installed in the pre-combustion chamber (5); a sealing ring (7) is provided between the sliding pre-combustion chamber top cover (8) and the inner wall of the pre-combustion chamber; a pre-combustion chamber push rod (10) is connected to the sliding pre-combustion chamber top cover (8); the pre-combustion chamber push rod (10) passes through a pre-combustion chamber push rod control valve (9); the pre-combustion chamber push rod control valve (9) controls the up and down displacement of the pre-combustion chamber push rod (10); a spark plug (6) and a pre-combustion chamber oxygen nozzle (12) are respectively installed on the sliding pre-combustion chamber top cover (8); oxygen stored in an oxygen cylinder (15) is decompressed by a pressure reducing valve (13) and is flexibly connected to the pre-combustion chamber oxygen nozzle (12) through a pipeline; The electronic control unit (16) obtains a speed signal a by connecting to an existing speed sensor in the internal combustion engine; The electronic control unit (16) obtains a torque signal b by connecting to an existing control handle or pedal in the internal combustion engine; The electronic control unit (16) is connected to the temperature and pressure sensor (4) via a wire, and obtains the pressure and temperature in the pre-combustion chamber (5) by receiving the temperature and pressure signal c; The electronic control unit (16) is connected to the spark plug (6) via a wire and controls the spark plug (6) to spark by sending an ignition signal d; The electronic control unit (16) is connected to the pre-combustion chamber push rod control valve (9) through a wire, and controls the movement of the pre-combustion chamber push rod (10) by receiving a pre-combustion chamber push rod position feedback signal e and sending a pre-combustion chamber push rod control signal f; The electronic control unit (16) is connected to the pre-combustion chamber oxygen nozzle (12) through a wire, and controls the pre-combustion chamber oxygen nozzle (12) to spray by sending a spray signal g; The electronic control unit (16) is connected to the hydrogen flow sensor (17) via a wire, and obtains the mass flow of hydrogen entering the cylinder by receiving the hydrogen flow signal h; The electronic control unit (16) is connected to the throttle valve (18) via a wire and controls the opening angle of the throttle valve (18) by sending a throttle valve control signal q.

2. The method for controlling a hydrogen-oxygen internal combustion engine based on a controllable pre-combustion chamber volume as claimed in claim 1, characterized in that: The following steps are involved: The electronic control unit (16) sends a throttle control signal q to open the throttle (18) to allow hydrogen to enter the cylinder, and the hydrogen flow rate is set to The electronic control unit (16) receives the speed signal a, the load signal b, and the temperature and pressure signal c to obtain the actual speed (N) and actual torque (T A ), the pressure (P) and temperature (T) in the pre-combustion chamber; the electronic control unit (16) calculates the oxygen injection amount per cycle according to formula (1) Where: T B - target torque, η - theoretical energy conversion efficiency of the internal combustion engine is 0.3, q - lower calorific value of hydrogen, α - ratio of the pre-combustion chamber volume to the total combustion chamber volume, β - theoretically derived correction factor of 1.15; The electronic control unit (16) calculates the excess air coefficient λ in the pre-combustion chamber according to formula (2): pc : Where: V pc -precombustion chamber volume; R-gas constant; - molar mass of hydrogen; When the λ in the precombustion chamber pc Does not satisfy 0.8≤λ pc When the value is less than or equal to 1.2, the electronic control unit (16) sends a pre-combustion chamber push rod control signal f to control the pre-combustion chamber push rod (10) to drive the sliding pre-combustion chamber top cover (8) to adjust the volume V of the pre-combustion chamber (5). pc The electronic control unit (16) calculates the excess air coefficient λ after the pre-combustion chamber volume changes according to formula (3): pc·δ : Where: V pc·δ -Adjusted pre-chamber volume; T δ - The temperature in the pre-combustion chamber after adjustment; P δ -Adjust the pressure in the precombustion chamber; α δ - Ratio of adjusted pre-chamber volume to total combustion chamber volume; When the actual torque of the internal combustion engine (T A ) changes to the target torque (T B )hour, Under this condition, the electronic control unit (16) controls the pre-combustion chamber oxygen nozzle (12) to spray oxygen in an amount of The electronic control unit (16) calculates the λ in the pre-combustion chamber after the oxygen is injected pc , if 0.8≤λ pc ≤1.2, the electronic control unit (16) only receives the pre-combustion chamber push rod position feedback signal e marked push rod position HT; when λ pc <0.8, the electronic control unit (16) controls the pre-combustion chamber push rod control valve (9) by sending a pre-combustion chamber push rod control signal f to drive the pre-combustion chamber push rod (10) to drive the sliding pre-combustion chamber top cover (8) to move synchronously to the min position, each time moving 1mm until λ pc·δ ≥0.8 and then stops moving, the electronic control unit (16) receives the pre-combustion chamber push rod position feedback signal e and marks the push rod position HT; if λ pc >1.2, the electronic control unit (16) controls the pre-combustion chamber push rod control valve (9) by sending a pre-combustion chamber push rod control signal f to drive the pre-combustion chamber push rod to drive the sliding pre-combustion chamber top cover (8) to move synchronously to the max position, each time moving 1mm until λ pc·δ ≤1.2 and stops moving. The electronic control unit (16) receives the pre-combustion chamber push rod position feedback signal e and marks the push rod position HT. During the exhaust phase, the electronic control unit (16) controls the pre-combustion chamber push rod control valve (9) by sending a pre-combustion chamber push rod control signal f to drive the pre-combustion chamber push rod (10) and the sliding pre-combustion chamber top cover (8) to move downward to the minimum pre-combustion chamber volume position min; during the intake phase, the electronic control unit (16) controls the pre-combustion chamber push rod (10) controlled by the pre-combustion chamber push rod control valve (9) to return to the previous position HT by sending a pre-combustion chamber push rod control signal f; In the process of the electronic control unit (16) sending a pre-combustion chamber push rod control signal f to control the pre-combustion chamber push rod (10) controlled by the pre-combustion chamber push rod control valve (9), the electronic control unit (16) receives the pre-combustion chamber push rod position feedback signal e sent from the pre-combustion chamber push rod control valve (9). When the relative error between the displacement of the pre-combustion chamber push rod (10) provided by the pre-combustion chamber push rod position feedback signal e and the target is greater than 5%, the electronic control unit (16) determines that the system has failed; when the position of the pre-combustion chamber push rod (10) provided by the pre-combustion chamber push rod position feedback signal e exceeds the minimum pre-combustion chamber volume min and the maximum pre-combustion chamber volume max, the electronic control unit (16) determines that the system has failed; when a system failure occurs, the electronic control unit (16) immediately sends a pre-combustion chamber push rod control signal f to control the pre-combustion chamber push rod control valve (9) to drive the pre-combustion chamber push rod (10) back to the middle of the pre-combustion chamber volume.

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