Argon circulation hydrogen engine based on composite water spraying and active pre-combustion chamber and in-cylinder temperature control method of argon circulation hydrogen engine

Abstract

The invention provides an argon circulation hydrogen engine based on composite water spraying and an active pre-combustion chamber and an in-cylinder temperature active control method of the argon circulation hydrogen engine. The engine is based on an argon circulation hydrogen engine structure of composite water spraying and an active pre-combustion chamber, a fuel oil supply mode of medium-pressure hydrogen spraying of the active pre-combustion chamber is designed, and combustible mixed gas based on hydrogen / oxygen / argon is achieved in a combustion chamber of the internal combustion engine. Hydrogen serves as fuel of the internal combustion engine. Oxygen serves as an oxidant to participate in combustion. Argon is used as a medium for pushing the piston. In the working process of the internal combustion engine, combustion process optimization control and in-cylinder steam supplementation are achieved by combining in-cylinder high-temperature water spraying with an air inlet channel water spraying strategy, so that combustion stability and heat efficiency are improved.

Description

Technical Field

[0001] The invention relates to the technical field of internal combustion engines, and in particular to an argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber and a method for controlling the in-cylinder temperature thereof. Background Art

[0002] As a carbon-free renewable energy source, hydrogen has the potential to become an internal combustion engine fuel that achieves ultra-lean combustion and high thermal efficiency. However, hydrogen fuel engines currently still face the problem of NOx emissions, and there is still room for further improvement in their thermal efficiency. The Argon Power Cycle (APC) hydrogen fuel engine is a closed cycle engine that uses argon to replace nitrogen in the air, uses argon-oxygen mixed gas as an oxidant, and uses hydrogen as fuel. Under ideal conditions, since the reaction only produces water, argon can be separated from water vapor at the exhaust end and continued to be used as a circulating working fluid.

[0003] However, due to the increase in the specific heat capacity ratio of the working fluid, its compression end temperature, combustion speed, etc. also increase, which will lead to the occurrence of abnormal combustion phenomena such as detonation, thereby limiting the actual working compression ratio of the APC hydrogen fuel engine.

[0004] Therefore, the development of an argon cycle hydrogen engine based on composite water injection and active precombustion chamber and its in-cylinder temperature control method are of great significance to suppress knock in the original working conditions. Summary of the invention

[0005] The object of the present invention is to provide an argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber and a method for controlling the in-cylinder temperature thereof, so as to solve the problems existing in the prior art.

[0006] The technical solution adopted to achieve the purpose of the present invention is as follows: an argon cycle hydrogen engine based on compound water injection and active pre-combustion chamber, including an argon cycle internal combustion engine body, an active pre-combustion chamber ignition system, a fuel supply system, a compound water injection system and an electronic control system.

[0007] The argon cycle internal combustion engine body comprises a cylinder block, a cylinder head and a piston. A cylinder head is arranged on the top of the cylinder block. A piston is arranged inside the cylinder block. The piston, the cylinder block and the cylinder head together form a combustion chamber. An intake manifold and an exhaust manifold are arranged on both sides of the cylinder head.

[0008] The active pre-combustion chamber ignition system includes a pre-combustion chamber cavity, and a spark plug and a medium-pressure hydrogen nozzle arranged in the pre-combustion chamber cavity. The bottom of the pre-combustion chamber cavity is provided with at least two jet spray holes. The jet spray holes are arranged on the cylinder head and face the combustion chamber.

[0009] The fuel supply system includes a hydrogen fuel tank and a hydrogen outlet pipeline. The hydrogen fuel tank stores hydrogen fuel. One end of the hydrogen outlet pipeline is connected to the hydrogen fuel tank, and the other end is connected to the medium-pressure hydrogen nozzle. A medium-pressure hydrogen pressure reducing valve and a medium-pressure hydrogen flow sensor are arranged on the pipeline of the hydrogen outlet pipeline.

[0010] The composite water injection system includes a water tank, a water pump, a high-pressure water pump, a high-pressure water common rail, a heat exchanger, an in-cylinder high-temperature water nozzle and an intake water nozzle. The intake water nozzle is installed on the intake manifold. The intake water nozzle is connected to the water pump through a pipeline. The in-cylinder high-temperature water nozzle is installed in the combustion chamber. The in-cylinder high-temperature water nozzle is connected to the high-pressure water common rail through a pipeline. The heat exchanger is connected to the high-pressure water common rail through a pipeline. The water tank stores water for normal pressure injection. The water tank has a water inlet and two water outlets. The two water outlets of the water tank are connected to the heat exchanger and the water pump respectively. A high-pressure water pump is arranged on the pipeline between the water tank and the heat exchanger. A water temperature balance pipeline is connected between the outlet and the inlet of the heat exchanger. A water temperature balance valve is arranged on the water temperature balance pipeline. A temperature sensor is arranged on the pipeline between the high-pressure water common rail and the heat exchanger.

[0011] The electronic control system includes a closed-loop controller, and a combination of one or more of an ion current sensing unit, a pressure sensor or a knock sensor. The ion current sensing unit includes an ion current signal processing device, a high-voltage ion current power supply device and an in-cylinder ion current sensor. The medium-pressure hydrogen pressure reducing valve, the medium-pressure hydrogen flow sensor, the intake water nozzle, the in-cylinder high-temperature water nozzle, the high-pressure water common rail, the ion current signal processing device, the temperature sensor, the water temperature balance valve, the high-pressure water pump and the water pump are all connected to the closed-loop controller. The knock sensor, the pressure sensor, and the in-cylinder ion current sensor are installed in the combustion chamber of the argon cycle internal combustion engine body. The knock sensor is connected to the closed-loop controller through a wire. The pressure sensor is connected to the closed-loop controller through a wire. The high-voltage ion current power supply device applies voltage to the cylinder block and the combustion chamber of the argon cycle internal combustion engine body.

[0012] During operation, hydrogen is used as the fuel of the internal combustion engine, oxygen is used as the oxidant to participate in the combustion, and argon is used as the medium to push the piston. Oxygen, argon and hydrogen are mixed in the combustion chamber. By burning hydrogen in the combustion chamber, argon expands, thereby outputting power. The ion current sensing unit, pressure sensor and / or knock sensor monitor the knock signal in the cylinder. The knock sensor and pressure sensor transmit the output signal to the closed-loop controller. The in-cylinder ion current sensor detects the in-cylinder ion current signal and transmits it to the ion current signal processing device. The ion current signal processing device performs signal processing on the in-cylinder ion current signal, extracts the in-cylinder knock characteristic signal and transmits it to the closed-loop controller. After the water for injection in the water tank is transported to the intake water nozzle, the intake water nozzle performs atomization water spraying to reduce the intake temperature and prevent the engine from overheating. After the water for injection in the water tank is pressurized and heated by the high-pressure water pump and the heat exchanger, it is accumulated in the common rail cavity of the high-pressure water common rail. When the difference between the maximum characteristic value of in-cylinder knock and the lower threshold is greater than zero, the high-pressure water common rail eliminates the pressure fluctuation in the injection water, and then delivers the injection water to the high-temperature water nozzle in the cylinder for injection into the cylinder, thereby increasing the mass of the working medium and improving the thermal efficiency of the internal combustion engine. The closed-loop controller adjusts the in-cylinder water injection strategy and the intake port water injection strategy based on the current working state of the internal combustion engine and the characteristic signal of in-cylinder knock. The closed-loop controller adjusts the fuel supply strategy based on the current working state of the internal combustion engine and the characteristic signal of in-cylinder knock.

[0013] Furthermore, a condenser is included. The condenser is in one-way communication with the water inlet of the water tank. The condenser is in communication with the intake manifold and the exhaust manifold. The high-temperature exhaust gas enters the condenser through the exhaust manifold for condensation and separation. After condensation, the water vapor is converted into liquid water, thereby realizing the separation of argon and water vapor. The separated liquid water is passed into the water tank for storage, and the separated argon is supplied to the intake manifold again to realize argon circulation, thereby solving the problem of how to realize the reuse of argon in an argon atmosphere.

[0014] Furthermore, the closed-loop controller adjusts the medium-pressure hydrogen pressure reducing valve according to the throttle opening, and controls the hydrogen delivery pressure range to be 10 bar to 100 bar. After the hydrogen fuel is transported to the medium-pressure hydrogen nozzle and the injection pressure is adjusted for injection, the hydrogen fuel enters the pre-combustion chamber cavity. With the help of medium-pressure injection and the pressure difference between the pre-combustion chamber and the main combustion chamber, the injected hydrogen is mixed with the oxygen / argon in the combustion chamber to form a uniform mixture. The spark plug ignites the mixture in the pre-combustion chamber at the appropriate ignition time and performs jet ignition on the main combustion chamber.

[0015] Furthermore, the water tank uses a heat exchanger to maintain the water temperature. The heat source of the heat exchanger comes from the heat released during the working process of the engine.

[0016] Furthermore, the high-voltage ion current power supply device, the ion current signal processing device and the closed-loop controller are all powered by a vehicle-mounted battery.

[0017] Furthermore, the pipeline adopts heat-insulating, heat-preserving and pressure-resistant stainless steel pipes or hoses.

[0018] Furthermore, the high-voltage ion current power supply device applies a DC voltage of 50 to 300 V to the cylinder block and the combustion chamber of the argon cycle internal combustion engine body.

[0019] Furthermore, the ion current signal processing device filters, amplifies, performs digital-to-analog conversion, integrates, and performs maximum eigenvalue extraction signal processing on the monitored ion current signal, extracts in-cylinder knock information, and communicates with a closed-loop controller via a CAN communication protocol.

[0020] Furthermore, the throttle valve adjusts the intake air volume according to the engine load.

[0021] The present invention also discloses a method for operating the above-mentioned argon cycle hydrogen engine based on compound water injection and active pre-combustion chamber, wherein the closed-loop controller controls the water temperature balance valve to adjust the high-pressure water output temperature and the output flow of the high-pressure water pump in real time according to the target water temperature. The closed-loop controller adjusts the injection timing, injection pulse width and water injection amount of the high-temperature water nozzle in the cylinder in real time according to the working state of the internal combustion engine. The closed-loop controller adjusts the injection strategy of the water pump and the intake manifold water nozzle in real time according to the working state of the internal combustion engine and the knock intensity in the cylinder to assist in the water injection in the cylinder. The closed-loop controller adjusts the fuel supply strategy of the medium-pressure hydrogen pressure reducing valve and the medium-pressure hydrogen flow sensor in real time according to the working state of the internal combustion engine and the knock intensity in the cylinder to assist in the water injection in the cylinder to suppress knock.

[0022] The present invention also discloses a vehicle system, comprising any one of the above-mentioned argon cycle hydrogen engines based on composite water injection and active pre-combustion chamber.

[0023] The technical effects of the present invention are unquestionable:

[0024] A. The closed-loop controller accurately adjusts the injection pulse width and injection timing of the high-temperature water nozzle in the cylinder, combines the intake water injection strategy and the fuel supply strategy to achieve the most efficient and optimized cylinder knock control, and optimizes the cylinder combustion to improve the performance of the internal combustion engine;

[0025] B. The fuel supply system of the argon cycle hydrogen fuel internal combustion engine is simplified through the medium-pressure hydrogen injection system of the active pre-combustion chamber, and the fuel injection work of the active pre-combustion chamber and the main combustion chamber is completed with a single injection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the argon cycle hydrogen engine system based on composite water injection and active precombustion chamber.

[0027] In the figure: hydrogen fuel tank 1, medium-pressure hydrogen pressure reducing valve 2, throttle valve 3, hydrogen outlet pipe 4, intake manifold 5, medium-pressure hydrogen flow sensor 6, intake water nozzle 7, in-cylinder ion current sensor 8, spark plug 9, medium-pressure hydrogen nozzle 10, closed-loop controller 11, high-voltage ion current power supply device 12, in-cylinder high-temperature water nozzle 13, high-pressure water common rail 14, ion current signal processing device 15, exhaust manifold 16, temperature sensor 17, heat exchanger 18, water temperature balance valve 19, high-pressure water pump 20, water pump 21, water tank 22, knock sensor 23, argon cycle internal combustion engine body 24, condenser 25, pressure sensor 26, pre-combustion chamber cavity 27. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the embodiments, but it should not be understood that the above subject matter of the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the art, which should all be included in the protection scope of the present invention.

[0029] Embodiment 1:

[0030] See also Figure 1 In view of the knock problem of argon cycle hydrogen fuel engine, this embodiment proposes an argon cycle hydrogen engine based on composite water injection and active precombustion chamber, which simplifies the fuel supply system by relying on medium-pressure hydrogen injection in an active precombustion chamber, including an argon cycle internal combustion engine body 24, an active precombustion chamber ignition system, a fuel supply system, a composite water injection system and an electronic control system.

[0031] The argon cycle internal combustion engine body 24 includes a cylinder block, a cylinder head and a piston. A cylinder head is provided on the top of the cylinder block. A piston is provided inside the cylinder block. The piston, the cylinder block and the cylinder head together form a combustion chamber. An intake manifold 5 and an exhaust manifold 16 are provided on both sides of the cylinder head.

[0032] The active pre-combustion chamber ignition system comprises a pre-combustion chamber cavity 27, and a spark plug 9 and a medium-pressure hydrogen nozzle 10 arranged in the pre-combustion chamber cavity 27. At least two jet spray holes are arranged at the bottom of the pre-combustion chamber cavity 27. The jet spray holes are arranged on the cylinder head and face the combustion chamber.

[0033] The fuel supply system includes a hydrogen fuel tank 1 and a hydrogen outlet pipe 4. Hydrogen fuel is stored in the hydrogen fuel tank 1. One end of the hydrogen outlet pipe 4 is connected to the hydrogen fuel tank 1, and the other end is connected to the medium-pressure hydrogen nozzle 10. A medium-pressure hydrogen pressure reducing valve 2 and a medium-pressure hydrogen flow sensor 6 are arranged on the pipeline of the hydrogen outlet pipe 4.

[0034] The composite water injection system includes a water tank 22, a water pump 21, a high-pressure water pump 20, a high-pressure water common rail 14, a heat exchanger 18, an in-cylinder high-temperature water nozzle 13 and an intake water nozzle 7. The intake water nozzle 7 is installed on the intake manifold 5. The intake water nozzle 7 is connected to the water pump 21 through a pipeline. The in-cylinder high-temperature water nozzle 13 is installed in the combustion chamber. The in-cylinder high-temperature water nozzle 13 is connected to the high-pressure water common rail 14 through a pipeline. The heat exchanger 18 is connected to the high-pressure water common rail 14 through a pipeline. The water tank stores water for normal pressure injection. The water tank 22 has a water inlet and two water outlets. The two water outlets of the water tank 22 are respectively connected to the heat exchanger 18 and the water pump 21. A high-pressure water pump 20 is arranged on the pipeline between the water tank 22 and the heat exchanger 18. A water temperature balance pipeline is connected between the outlet and the inlet of the heat exchanger 22. A water temperature balance valve 19 is arranged on the water temperature balance pipeline. A temperature sensor 17 is provided on the pipeline between the high-pressure water common rail 14 and the heat exchanger 18 .

[0035] The electronic control system includes a closed-loop controller 11, and a combination of one or more of an ion current sensing unit, a pressure sensor 26 or a knock sensor 23. The ion current sensing unit includes an ion current signal processing device 15, a high-voltage ion current power supply device 12 and an in-cylinder ion current sensor 8. The medium-pressure hydrogen pressure reducing valve 2, the medium-pressure hydrogen flow sensor 6, the intake water nozzle 7, the in-cylinder high-temperature water nozzle 13, the high-pressure water common rail 14, the ion current signal processing device 15, the temperature sensor 17, the water temperature balance valve 19, the high-pressure water pump 20 and the water pump 21 are all connected to the closed-loop controller 11. The in-cylinder ion current sensor 8 is installed on the cylinder head of the argon cycle internal combustion engine body 24. The pressure sensor 26 is installed in the combustion chamber of the argon cycle internal combustion engine body 24. The knock sensor 23 is installed on the cylinder body of the argon cycle internal combustion engine body 24. The knock sensor 23 is connected to the closed-loop controller 11 through a wire. The pressure sensor 26 is connected to the closed-loop controller 11 through a wire. The high-voltage ion current power supply device 12 applies voltage to the cylinder block and the combustion chamber of the argon cycle internal combustion engine block 24 .

[0036] During operation, hydrogen is used as the fuel of the internal combustion engine, oxygen is used as the oxidant to participate in the combustion, and argon is used as the medium to push the piston. Oxygen, argon and hydrogen are mixed in the combustion chamber. By burning hydrogen in the combustion chamber, argon expands, thereby outputting power. The ion current sensing unit, pressure sensor 26 and / or knock sensor 23 monitor the knock signal in the cylinder. The knock sensor 23 and pressure sensor 26 transmit the output signal to the closed-loop controller 11. The cylinder ion current sensor 8 detects the cylinder ion current signal and transmits it to the ion current signal processing device 15. The ion current signal processing device 15 performs signal processing on the cylinder ion current signal, extracts the cylinder knock characteristic signal and transmits it to the closed-loop controller 11. After the injection water in the water tank 22 is transported to the intake water nozzle 7, the intake water nozzle 7 performs atomization water spraying to reduce the intake temperature and prevent the engine from overheating. The injection water in the water tank 22 is pressurized and heated by the high-pressure water pump 20 and the heat exchanger 18, and then accumulated in the common rail cavity of the high-pressure water common rail 14. When the difference between the maximum characteristic value of the in-cylinder knock and the lower threshold is greater than zero, the high-pressure water common rail 14 eliminates the pressure fluctuation in the injection water, and then delivers the injection water to the high-temperature water nozzle 13 in the cylinder for injection into the cylinder, thereby increasing the mass of the working medium and improving the thermal efficiency of the internal combustion engine. The closed-loop controller 11 adjusts the in-cylinder water injection strategy and the intake manifold water injection strategy based on the current working state of the internal combustion engine and the characteristic signal of the in-cylinder knock. The closed-loop controller 11 adjusts the fuel supply strategy based on the current working state of the internal combustion engine and the characteristic signal of the in-cylinder knock. In actual production, the working state of the internal combustion engine is provided by the crankshaft sensor, the camshaft sensor, the intake pressure temperature sensor and / or the original engine controller.

[0037] This embodiment provides a new idea for achieving zero emission, higher thermal efficiency, more stability, and higher control accuracy of argon cycle internal combustion engine technology. During the operation of the internal combustion engine, high-temperature water is injected into the cylinder and combined with the intake water injection strategy to achieve optimized control of the combustion process and steam supplement in the cylinder to improve combustion stability and thermal efficiency. Water injection reduces the temperature in the cylinder and reduces the reaction speed, which can suppress knocking in the original working condition, achieve an increase in compression ratio and load, and thus may obtain higher thermal efficiency.

[0038] Embodiment 2:

[0039] The main content of this embodiment is the same as that of embodiment 1, wherein a condenser 25 is further included. The condenser 25 is in one-way communication with the water inlet of the water tank 22. The condenser 22 is in communication with the intake manifold 5 and the exhaust manifold 16. The high-temperature exhaust gas enters the condenser 25 through the exhaust manifold 16 for condensation and separation. After condensation, the water vapor is converted into liquid water to achieve the separation of argon and water vapor. The separated liquid water is passed into the water tank 22 for storage. The separated argon is supplied to the intake manifold 5 again to achieve argon circulation, solving the problem of how to reuse argon in an argon atmosphere. The problem of argon supply under an argon environment is that the 400°C high-temperature exhaust gas (argon, water vapor) discharged from the exhaust manifold is cooled to below 85°C by a condenser for condensation and separation. After condensation, the water vapor is converted into liquid water to achieve the separation of argon and water vapor. The separated water vapor is passed into the water tank for storage. The separated argon is passed into the intake manifold again to achieve argon circulation, solving the problem of how to reuse argon in an argon atmosphere.

[0040] Embodiment 3:

[0041] The main contents of this embodiment are the same as those of Embodiment 1 or 2, wherein the closed-loop controller 11 adjusts the medium-pressure hydrogen pressure reducing valve 2 according to the throttle opening, and controls the hydrogen delivery pressure range to be 10 bar to 100 bar. The medium-pressure hydrogen flow sensor 6 can provide real-time feedback of the hydrogen flow; the closed-loop controller 11 can adjust the medium-pressure hydrogen pressure reducing valve 2 in real time according to the working state of the internal combustion engine and the knock signal in the cylinder to adjust the fuel supply and improve the combustion efficiency of the internal combustion engine. After the hydrogen fuel is transported to the medium-pressure hydrogen nozzle and the injection pressure is adjusted for injection, the hydrogen fuel enters the pre-combustion chamber cavity 27. With the help of medium-pressure injection and the pressure difference between the pre-combustion chamber and the main combustion chamber, the injected hydrogen is mixed with the oxygen / argon in the combustion chamber to form a uniform mixture. The spark plug 9 ignites the mixture in the pre-combustion chamber at the appropriate ignition time and performs jet ignition on the main combustion chamber.

[0042] Embodiment 4:

[0043] The main content of this embodiment is the same as any one of the embodiments 1 to 3, wherein the water tank 22 uses a heat exchanger 18 to maintain the water temperature. The heat source of the heat exchanger 18 comes from the heat released during the working process of the engine.

[0044] Embodiment 5:

[0045] The main contents of this embodiment are the same as any one of embodiments 1 to 4, wherein the high-voltage ion current power supply device 12, the ion current signal processing device 15 and the closed-loop controller 11 are all powered by a vehicle-mounted battery. The water for normal pressure injection is stored in a water tank 22. A heat exchanger 18 is connected to the side wall of the water tank 22. The heat source of the heat exchanger 18 comes from the heat released during the working process of the internal combustion engine.

[0046] Since water at 0°C may freeze, a heat exchanger 18 is used to maintain the water temperature. The heat source of the heat exchanger 18 comes from the heat released during the working process of the internal combustion engine. In order to achieve precise control of the temperature of the water in the water tank, the water tank liquid level and temperature sensor 17 is used to monitor the water temperature in the tank in real time, and transmit the information back to the closed-loop controller 11 to provide basic information for calculating the required heat when the current water tank temperature is lower than 15°C. The closed-loop control 11 combines the PID closed-loop control strategy, and uses different proportional coefficients, integral coefficients and differential coefficients to control the opening and closing of the water tank heating control valve 19, adjust the heat exchange intensity, and achieve precise control of the water temperature in the water tank, thereby effectively avoiding adverse phenomena such as freezing of the water in the tank.

[0047] On this basis, the water is pressurized to 15-40MPa by a high-pressure water pump, and then heated by a heat exchanger. According to the heat exchange efficiency of the heat exchanger of 60% and the exhaust temperature of 400℃, the temperature of the heated water is approximately 200℃. The temperature sensor will feed back the water temperature signal to the closed-loop controller. According to the collected intake volume, speed and calibration MAP information, the closed-loop controller is fed back to determine the required temperature of 120-180℃. After that, the water temperature balance valve is opened to neutralize the temperature of the unheated water and the heated water to reach the target temperature. It is then stored in the high-pressure water common rail. The pressure of the high-pressure water common rail is monitored in real time by the rail pressure sensor and transmitted to the closed-loop controller. The closed-loop controller makes a decision based on the comparison of the target value with the current value, and controls the outlet flow of the high-pressure water pump to increase or decrease the pressure of the high-pressure water common rail. The role of the high-pressure water common rail here is to realize the distribution of injection water in each cylinder and suppress the pressure fluctuation of the water injection process, so as to provide guarantee for the precise control of the water injection process.

[0048] Embodiment 6:

[0049] The main contents of this embodiment are the same as any one of Embodiments 1 to 5, wherein the pipeline adopts a heat-insulating, heat-resistant and pressure-resistant stainless steel pipe or hose.

[0050] Embodiment 7:

[0051] The main contents of this embodiment are the same as any one of embodiments 1 to 6, wherein in actual production, the ion current method, pressure sensor and knock sensor can select one or more combinations to monitor the knock signal in the cylinder.

[0052] The high-voltage ion current power supply device 12 applies a DC voltage of 50 to 300 V to the cylinder body and combustion chamber of the argon cycle internal combustion engine body 24. The high-voltage ion current power supply device 12 applies a DC voltage of 50 to 300 V to the cylinder body and combustion chamber of the argon cycle internal combustion engine body 24. During the combustion process, the combustible mixture will produce chemical ionization and thermal ionization reactions, and the generated ion directional flow forms a weak current in the detection circuit. The in-cylinder ion current sensor 8 detects the in-cylinder ion current signal and transmits it to the ion current signal processing device 15. The ion current signal processing device 15 performs signal processing such as filtering, amplification, digital-to-analog conversion, integration, and maximum eigenvalue extraction on the monitored ion current signal, extracts the in-cylinder knock information, and communicates with the closed-loop controller 11 through the CAN communication protocol, providing a feedback signal for the closed-loop controller 11 to control the injection strategy of the high-temperature water nozzle 13 in the cylinder, so that real-time closed-loop control of in-cylinder knock can be achieved. The closed-loop controller 11 adjusts the compound water injection strategy according to the current working state of the internal combustion engine and the in-cylinder knock characteristic signal.

[0053] The pressure sensor 26 generates electric charge through piezoelectric crystals when subjected to pressure changes. The change in charge can be converted into a voltage signal to reflect the pressure fluctuation. The piezoelectric sensor can respond to pressure changes in a very short time; the pressure sensor 26 is installed on the cylinder body in the combustion chamber and can directly sense the pressure fluctuation in the combustion chamber. Knock usually produces a certain amount of high-frequency noise (usually between 5kHz and 30kHz). Therefore, the sensor will convert the pressure change into an electrical signal and then detect whether there is a knock feature through frequency analysis. After detecting the abnormal high-frequency component, the pressure sensor 26 transmits the knock signal to the closed-loop controller 11.

[0054] The knock sensor 23 is installed in the combustion chamber. The frequency response range of the knock sensor 23 is usually set at about 20kHz, and the vibration caused by knock is usually in the range of 5kHz to 30kHz. The threshold value of the vibration intensity of the knock sensor is usually expressed in the form of a voltage signal, expressed as the voltage generated per unit vibration intensity (for example, mV / Pa or mV / g). When the voltage output by the sensor exceeds a preset threshold, it indicates that knock has occurred. The specific frequency response range and vibration intensity threshold need to be dynamically adjusted according to the actual engine system and different engine operating conditions. When the knock sensor 23 detects the knock signal in the cylinder, it transmits the knock signal to the closed-loop controller 11.

[0055] Embodiment 8:

[0056] The main contents of this embodiment are the same as any one of Embodiments 1 to 7, wherein the ion current signal processing device 15 filters, amplifies, performs digital-to-analog conversion, integrates, and performs maximum eigenvalue extraction signal processing on the monitored ion current signal, extracts the in-cylinder knock information, and communicates with the closed-loop controller 11 via the CAN communication protocol.

[0057] The in-cylinder water injection strategy is generally selected to spray water into the cylinder during the intake stroke or the compression stroke. The heat of evaporation of the early sprayed water droplets mainly comes from the structural components in the cylinder, and the working fluid cooling is not obvious; while too late injection will cause the spray liquid column to hit the piston, resulting in uneven distribution of water droplets; the intake duct water injection strategy needs to adjust the water injection amount according to the oxygen / argon temperature and the in-cylinder knock situation. For example, in an argon cycle hydrogen engine with a compression ratio of 9.6, the intake duct water injection amount is controlled at 16mg per cycle to better suppress knock. As the load increases, the maximum water injection amount can be increased to 52mg per cycle; the composite water injection strategy can adjust the in-cylinder water injection timing, water injection pulse width and intake water injection amount according to the in-cylinder knock tendency and the in-cylinder knock intensity. When the difference between the maximum characteristic value of the in-cylinder knock and the lower threshold is greater than zero, the closed-loop sensor control 11 controls the in-cylinder high-temperature water nozzle 13 to spray water in advance and adjusts the intake duct water nozzle 7 to increase the water injection amount to suppress the in-cylinder knock.

[0058] Taking the ion current signal system as an example, assuming that the speed is 2000r·min -1 , torque 80N·m, excess air coefficient = 1, the in-cylinder knock characteristic signal is provided by the ion current detection technology, and the CAN communication protocol is used to communicate with the closed-loop controller. On this basis, the lower threshold value of 5V is set. When the difference between the maximum characteristic value of the in-cylinder knock and the lower threshold value is greater than zero, the knock signal is transmitted to the closed-loop controller. According to the relationship curve between the difference and the water injection amount obtained in the experiment, the closed-loop controller accurately controls the water injection timing, injection pulse width and intake water injection amount in the cylinder, so that real-time control of in-cylinder knock can be achieved.

[0059] This embodiment establishes a compound water injection control system, which monitors the knock signal in the cylinder and performs compound water injection suppression on the knock tendency in the cylinder or when knock occurs in the cylinder.

[0060] Embodiment 9:

[0061] This embodiment provides a method for operating an argon cycle hydrogen engine based on a composite water injection and an active pre-combustion chamber according to any one of embodiments 1 to 8. The closed-loop controller 11 controls the water temperature balance valve 19 to adjust the high-pressure water output temperature and the output flow of the high-pressure water pump 20 in real time according to the target rail pressure and target water temperature requirements. The controller 11 adjusts the injection timing and injection pulse width of the high-temperature water nozzle 13 in real time according to the working state of the internal combustion engine. Specifically, the water is pressurized to 15 to 40 MPa using the high-pressure water pump 20. After the water is pressurized by the high-pressure water pump 20, the high-pressure water exchanges heat with the high-temperature exhaust gas in the heat exchanger 18. The water temperature signal after being heated by the heat exchanger 18 is fed back to the closed-loop controller 11 through the temperature sensor 17. The closed-loop controller 11 controls the water temperature balance valve 19 according to the feedback information to accurately control the water temperature.

[0062] On this basis, the heated high-pressure water is input and stored in the high-pressure water common rail 14. The pressure of the high-pressure water common rail is monitored in real time by the rail pressure sensor and transmitted to the closed-loop controller 11. The closed-loop controller 11 makes a decision based on the comparison between the target value and the current value, and controls the outlet flow of the high-pressure water pump 20 to increase or decrease the pressure of the high-pressure water common rail. The high-pressure water common rail 14 distributes the high-pressure water to the high-temperature water nozzles 13 in each cylinder of the internal combustion engine, and controls the injection into the combustion chamber at the appropriate time through the closed-loop controller 11, so as to reduce the knock tendency and increase the additional working medium during the operation of the internal combustion engine. In addition to the above-mentioned in-cylinder water injection strategy, the closed-loop controller 11 can also adjust the intake duct water injection strategy through the water pump 21 and the intake duct water nozzle 7 to assist the in-cylinder water injection to complete the composite water injection to control the in-cylinder knock.

[0063] The composite water injection strategy of this embodiment can significantly improve the emission characteristics of the internal combustion engine and increase the thermal efficiency of the internal combustion engine, enhance the control of the knock tendency in the cylinder, and effectively improve the working stability of the argon cycle internal combustion engine.

[0064] Embodiment 10:

[0065] This embodiment provides a vehicle system, including an argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber according to any one of Embodiments 1 to 8.

Claims

1. An argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber, characterized in that: It includes an argon cycle internal combustion engine body (24), an active pre-combustion chamber ignition system, a fuel supply system, a composite water injection system and an electronic control system; The argon cycle internal combustion engine body (24) comprises a cylinder block, a cylinder head and a piston; a cylinder head is provided on the top of the cylinder block; a piston is provided inside the cylinder block; the piston, the cylinder block and the cylinder head together form a combustion chamber; an intake manifold (5) and an exhaust manifold (16) are provided on both sides of the cylinder head respectively; The active pre-combustion chamber ignition system comprises a pre-combustion chamber cavity (27), and a spark plug (9) and a medium-pressure hydrogen nozzle (10) arranged in the pre-combustion chamber cavity (27); at least two jet spray holes are arranged at the bottom of the pre-combustion chamber cavity (27); the jet spray holes are arranged on the cylinder head and face the combustion chamber; The fuel supply system comprises a hydrogen fuel tank (1) and a hydrogen outlet pipeline (4); the hydrogen fuel tank (1) stores hydrogen fuel; one end of the hydrogen outlet pipeline (4) is connected to the hydrogen fuel tank (1), and the other end is connected to a medium-pressure hydrogen nozzle (10); a medium-pressure hydrogen pressure reducing valve (2) and a medium-pressure hydrogen flow sensor (6) are arranged on the pipeline of the hydrogen outlet pipeline (4); The composite water injection system comprises a water tank (22), a water pump (21), a high-pressure water pump (20), a high-pressure water common rail (14), a heat exchanger (18), an in-cylinder high-temperature water nozzle (13) and an intake manifold water nozzle (7); the intake manifold water nozzle (7) is installed on the intake manifold (5); the intake manifold water nozzle (7) is connected to the water pump (21) through a pipeline; the in-cylinder high-temperature water nozzle (13) is installed in the combustion chamber; the in-cylinder high-temperature water nozzle (13) is connected to the high-pressure water common rail (14) through a pipeline; the heat exchanger (18) is connected to the high-pressure water common rail (14) through a pipeline. ) is connected; the water tank stores water for normal pressure injection; the water tank (22) has a water inlet and two water outlets; the two water outlets of the water tank (22) are respectively connected to the heat exchanger (18) and the water pump (21); a high-pressure water pump (20) is provided on the pipeline between the water tank (22) and the heat exchanger (18); a water temperature balancing pipeline is connected between the outlet and the inlet of the heat exchanger (22); a water temperature balancing valve (19) is provided on the water temperature balancing pipeline; a temperature sensor (17) is provided on the pipeline between the high-pressure water common rail (14) and the heat exchanger (18); The electronic control system comprises a closed-loop controller (11), and a combination of one or more of an ion current sensing unit, a pressure sensor (26) or a knock sensor (23); the ion current sensing unit comprises an ion current signal processing device (15), a high-voltage ion current power supply device (12) and an in-cylinder ion current sensor (8); the medium-pressure hydrogen pressure reducing valve (2), a medium-pressure hydrogen flow sensor (6), an intake manifold water nozzle (7), an in-cylinder high-temperature water nozzle (13), a high-pressure water common rail (14), an ion current signal processing device (15), a temperature sensor (17 ), a water temperature balancing valve (19), a high-pressure water pump (20) and a water pump (21) are all connected to a closed-loop controller (11); the knock sensor (23), a pressure sensor (26) and an in-cylinder ion current sensor (8) are installed in a combustion chamber of an argon cycle internal combustion engine body (24); the knock sensor (23) is connected to the closed-loop controller (11) via a wire; the pressure sensor (26) is connected to the closed-loop controller (11) via a wire; the high-pressure ion current power supply device (12) applies voltage to the cylinder body and the combustion chamber of the argon cycle internal combustion engine body (24); When working, hydrogen is used as the fuel of the internal combustion engine, oxygen is used as the oxidant to participate in the combustion, and argon is used as the medium to push the piston; oxygen, argon and hydrogen are mixed in the combustion chamber; The argon gas is expanded by burning hydrogen in the combustion chamber, thereby outputting power; the ion current sensor unit, the pressure sensor (26) and / or the knock sensor (23) monitor the knock signal in the cylinder; the knock sensor (23) and the pressure sensor (26) transmit the output signal to the closed-loop controller (11); the in-cylinder ion current sensor (8) detects the in-cylinder ion current signal and transmits it to the ion current signal processing device (15); the ion current signal processing device (15) processes the in-cylinder ion current signal, extracts the in-cylinder knock characteristic signal and transmits it to the closed-loop controller (11); after the injection water in the water tank (22) is transported to the intake duct water nozzle (7), the intake duct water nozzle (7) performs atomization water spraying to reduce The intake air temperature is increased to prevent the engine from overheating; the injection water in the water tank (22) is pressurized and heated by the high-pressure water pump (20) and the heat exchanger (18), and then accumulated in the common rail cavity of the high-pressure water common rail (14); when the difference between the maximum characteristic value of the in-cylinder knock and the lower threshold value is greater than zero, the high-pressure water common rail (14) eliminates the pressure fluctuation in the injection water, and then delivers the injection water to the high-temperature water nozzle (13) in the cylinder for injection into the cylinder, thereby increasing the working fluid mass and improving the thermal efficiency of the internal combustion engine; the closed-loop controller (11) adjusts the in-cylinder water injection strategy and the intake duct water injection strategy according to the current working state of the internal combustion engine and the in-cylinder knock characteristic signal; the closed-loop controller (11) adjusts the fuel supply strategy according to the current working state of the internal combustion engine and the in-cylinder knock characteristic signal.

2. The argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber according to claim 1, characterized in that: The invention also comprises a condenser (25); the condenser (25) is in one-way communication with the water inlet of the water tank (22); the condenser (22) is in communication with the intake manifold (5) and the exhaust manifold (16); the high-temperature exhaust gas enters the condenser (25) through the exhaust manifold (16) for condensation and separation; the separated liquid water is passed into the water tank (22) for storage, and the separated argon gas is supplied to the intake manifold (5) again.

3. The argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber according to claim 1, characterized in that: The closed-loop controller (11) adjusts the medium-pressure hydrogen pressure reducing valve (2) according to the throttle opening, and controls the hydrogen delivery pressure range to be 10 bar to 100 bar.

4. The argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber according to claim 1, characterized in that: The water tank (22) uses a heat exchanger (18) to maintain water temperature; the heat source of the heat exchanger (18) comes from the heat released during the working process of the engine.

5. The argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber according to claim 1, characterized in that: The high-voltage ion current power supply device (12), the ion current signal processing device (15) and the closed-loop controller (11) are all powered by a vehicle-mounted storage battery.

6. The argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber according to claim 1, characterized in that: The pipelines are made of heat-insulating, heat-resistant and pressure-resistant stainless steel pipes or hoses.

7. The argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber according to claim 1, characterized in that: The high-voltage ion current power supply device (12) applies a direct current voltage of 50 to 300 V to the cylinder block and combustion chamber of the argon cycle internal combustion engine body (24).

8. The argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber according to claim 1, characterized in that: The ion current signal processing device (15) filters, amplifies, performs digital-to-analog conversion, integrates, and performs maximum eigenvalue extraction signal processing on the monitored ion current signal, extracts in-cylinder knock information, and communicates with the closed-loop controller (11) via the CAN communication protocol; the intake manifold (5) is provided with a throttle valve (3) to control the intake volume according to the engine load.

9. A method for operating an argon cycle hydrogen engine based on composite water injection and active precombustion chamber according to any one of claims 1 to 8, characterized in that: The closed-loop controller (11) controls the water temperature balance valve (19) to adjust the high-pressure water output temperature and the output flow of the high-pressure water pump (20) in real time according to the target water temperature; the closed-loop controller (11) adjusts the injection timing, injection pulse width and water injection amount of the high-temperature water nozzle (13) in the cylinder in real time according to the working state of the internal combustion engine; the closed-loop controller (11) adjusts the injection strategy of the water pump (21) and the intake manifold water nozzle (7) in real time according to the working state of the internal combustion engine and the knock intensity in the cylinder to assist the water injection in the cylinder; the closed-loop controller (11) adjusts the fuel supply strategy of the medium-pressure hydrogen pressure reducing valve (2) and the medium-pressure hydrogen flow sensor (6) in real time according to the working state of the internal combustion engine and the knock intensity in the cylinder to assist the water injection in the cylinder to suppress the knock.

10. A vehicle system, characterized in that: It comprises an argon cycle hydrogen engine based on composite water injection and active pre-combustion chamber according to any one of claims 1 to 8.

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