Rail pressure fluctuation control method and device for hydrogen internal combustion engine, storage medium and injection system

Abstract

The invention relates to a hydrogen internal combustion engine rail pressure fluctuation control method and device, a storage medium and an injection system. The control method comprises the steps that the current working condition is obtained, and the preset rail pressure and the preset fuel injection quantity are obtained according to the working condition; acquiring current rail pressure data and cylinder pressure data; according to the rail pressure data and the cylinder pressure data, the current injection flow is calculated; according to the injection flow and the current preset oil injection quantity, the current cylinder fluctuation coefficient is calculated; and when the cylinder fluctuation coefficient exceeds a preset threshold value, the current rail pressure adjustment amount is calculated according to the current preset rail pressure, and the rail pressure of all the air cylinders is adjusted according to the rail pressure adjustment amount. Compared with the prior art, the method has the advantages that injection fluctuation and multi-cylinder interference are reduced, and the combustion stability, efficiency and emission performance of the hydrogen internal combustion engine are improved.

Description

Technical Field

[0001] The present invention relates to the field of engine technology, and in particular to a method, device, storage medium and injection system for controlling rail pressure fluctuation of a hydrogen internal combustion engine. Background Art

[0002] As a clean energy, hydrogen energy is gaining more and more attention due to its zero emissions and high energy efficiency. In hydrogen internal combustion engines, the hydrogen injection system is the core component that determines the combustion efficiency and emission levels. Due to the low density and high diffusivity of hydrogen, the injection characteristics of hydrogen are more complex than those of traditional fuels. The hydrogen injection stability of a hydrogen internal combustion engine directly affects the uniformity and power performance of the combustion process, especially in multi-cylinder engines, where injection fluctuations between different cylinders may cause mutual interference between adjacent cylinders, thereby affecting the overall working stability and emission performance. Therefore, improving the hydrogen injection stability of hydrogen internal combustion engines has become one of the key technical challenges for their widespread application.

[0003] At present, the research on hydrogen injection stability is mainly focused on the design of hydrogen injectors, optimization of injection timing, and control of the combustion process. However, although some studies have proposed to stabilize the operation of hydrogen injectors by adjusting parameters such as injection timing, pressure, and flow, it is easy to ignore the injection fluctuation and interference between multiple cylinders, which affects the stability of the hydrogen injector and thus the overall performance of the hydrogen internal combustion engine. Therefore, how to accurately measure and feedback the stability of hydrogen injection in real time and improve the combustion stability of hydrogen internal combustion engines has become a problem that needs to be solved in this field. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a method, device, storage medium and injection system for controlling rail pressure fluctuation of a hydrogen internal combustion engine, which can accurately measure and feedback hydrogen injection stability in real time and improve the combustion stability of the hydrogen internal combustion engine.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] According to a first aspect of the present invention, a method for controlling rail pressure fluctuation of a hydrogen internal combustion engine is provided, comprising the following steps: S1, obtaining a current operating condition, and obtaining a preset rail pressure and a preset fuel injection amount according to the operating condition; S2, obtaining current rail pressure data and cylinder pressure data; S3, calculating a current injection flow rate according to the rail pressure data and the cylinder pressure data; S4, calculating a current cylinder fluctuation coefficient according to the injection flow rate and the current preset fuel injection amount; S5, when the cylinder fluctuation coefficient exceeds a preset threshold, calculating a current rail pressure adjustment amount according to the current preset rail pressure, adjusting the rail pressures of all cylinders according to the rail pressure adjustment amount, and returning to S2.

[0007] As a preferred technical solution, the injection flow rate is expressed as:

[0008]

[0009] Where m is the injection flow rate, C d is the pre-measured flow coefficient of the hydrogen injector, A is the effective cross-sectional area of ​​the hydrogen injector nozzle, ρ is the hydrogen density, P rail is the current rail pressure data, P chamber It is the current cylinder pressure data.

[0010] As a preferred technical solution, the cylinder fluctuation coefficient is expressed as:

[0011]

[0012] In the formula, σ m is the cylinder fluctuation coefficient, m set It is the current preset injection amount.

[0013] As a preferred technical solution, the rail pressure adjustment amount is expressed as:

[0014]

[0015] e rail =P set -P rail

[0016] In the formula, ΔP rail is the rail pressure adjustment, K pi is the proportional gain of the i-th cylinder, K di is the differential gain of the i-th cylinder, i≤n, n is the total number of cylinders, e rail is the rail pressure error, P set The preset rail pressure.

[0017] As a preferred technical solution, the control method further includes: in S2, simultaneously acquiring current injection timing data; in S5, simultaneously calculating the current cylinder injection timing adjustment amount according to the current cylinder fluctuation coefficient, and adjusting the injection timing according to the cylinder injection timing adjustment amount.

[0018] As a preferred technical solution, the cylinder injection timing adjustment amount is expressed as:

[0019] Δt=-K·(σ m -σ target )

[0020] Where Δt is the current cylinder injection timing adjustment, K is the preset adjustment coefficient, σ m is the cylinder fluctuation coefficient, σ target is the preset threshold.

[0021] As a preferred technical solution, in S5, when the cylinder fluctuation coefficient does not exceed the preset threshold, the rail pressure of all cylinders is maintained and the process returns to S1.

[0022] According to a second aspect of the present invention, there is provided a rail pressure fluctuation control device for a hydrogen internal combustion engine, comprising a memory, a processor, and a program stored in the memory, wherein the method described is implemented when the processor executes the program.

[0023] According to a third aspect of the present invention, there is provided a storage medium having a program stored thereon, wherein the program implements the method described above when executed.

[0024] According to a fourth aspect of the present invention, there is provided an injection system, comprising a hydrogen rail, an injector mounted on the hydrogen rail, and a cylinder connected to the injector, wherein the cylinder comprises a combustion chamber, the system further comprising a hydrogen rail pressure sensor, a cylinder pressure sensor, and an electronic control unit, wherein the hydrogen rail pressure sensor is mounted on the hydrogen rail, the cylinder pressure sensor is mounted on the cylinder, the hydrogen rail pressure sensor and the cylinder pressure sensor are respectively communicatively connected to the electronic control unit; the hydrogen rail pressure sensor is used to obtain rail pressure data in real time, and the cylinder pressure sensor is used to obtain cylinder pressure data in real time; the electronic control unit is used to receive the rail pressure data and the cylinder pressure data, and execute the rail pressure fluctuation control method of a hydrogen internal combustion engine.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention defines the injection flow rate of the injector as the mass flow rate of hydrogen injected into the combustion chamber through the hydrogen injector per unit time, and uses rail pressure data, cylinder pressure data, hydrogen density, the effective cross-sectional area of ​​the hydrogen injector nozzle and the pre-measured flow coefficient of the hydrogen injector to jointly calculate the real-time injection flow rate, and then calculate the cylinder fluctuation coefficient. The real-time rail pressure adjustment amount is calculated by judging the size of the cylinder fluctuation coefficient, thereby realizing real-time control of the rail pressure fluctuation of the hydrogen internal combustion engine. Based on the real-time feedback of the rail pressure, the hydrogen injection flow rate and injection timing can be accurately adjusted to reduce injection fluctuations, improve the hydrogen injection stability of the hydrogen internal combustion engine, and ensure the uniformity and efficiency of the combustion process;

[0027] 2. The present invention also calculates the real-time cylinder injection timing adjustment amount according to the real-time cylinder fluctuation coefficient, and then adjusts the injection timing in real time, which can effectively reduce the injection fluctuation interference between the cylinders in the multi-cylinder hydrogen internal combustion engine, optimize the hydrogen injection timing and rail pressure of each cylinder, make the hydrogen injection of each cylinder of the engine more uniform, and further improve the overall operation stability of the engine;

[0028] 3. The present invention can optimize the combustion process and improve the combustion efficiency of the hydrogen internal combustion engine by accurately controlling the rail pressure and the hydrogen injection process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of the injection system is provided in an embodiment of the present invention;

[0030] Among them: 101, hydrogen rail; 102, injector; 103, cylinder; 1031, combustion chamber; 104, hydrogen rail pressure sensor; 105, cylinder pressure sensor; 106, ECU;

[0031] Figure 2 A flow chart of a control method is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0033] Example

[0034] Regarding the research on hydrogen injection stability, there is still a lack of a method that can accurately measure and feedback the hydrogen injection stability in real time, especially how to optimize the hydrogen injection flow and injection timing by controlling the rail pressure to achieve higher stability. Rail pressure is a key parameter in the hydrogen injection system, and its stability has an important influence on the control of the hydrogen injection flow and the injection process. Therefore, a hydrogen injection stability optimization method based on real-time feedback control of rail pressure is proposed, which can effectively reduce injection fluctuations and improve combustion stability. The rail pressure fluctuation control method for a hydrogen internal combustion engine proposed in the present invention calculates parameters such as the hydrogen injection flow and the rail pressure fluctuation coefficient through real-time feedback of the rail pressure, accurately adjusts the rail pressure and the hydrogen injection timing, and optimizes the hydrogen injection process, thereby achieving efficient and stable operation of the hydrogen internal combustion engine.

[0035] like Figure 1 As shown, this embodiment provides an injection system for implementing the rail pressure fluctuation control method of a hydrogen internal combustion engine proposed in the present invention. The injection system includes a hydrogen rail 101, an injector 102 installed on the hydrogen rail 101, and a cylinder 103 connected to the injector 102, the cylinder 103 includes a combustion chamber 1031, the system also includes a hydrogen rail pressure sensor 104, a cylinder pressure sensor 105 and an electronic control unit (i.e., ECU 106), the hydrogen rail pressure sensor 104 is installed on the hydrogen rail 101, the cylinder pressure sensor 105 is installed on the cylinder 103, and the hydrogen rail pressure sensor 104 and the cylinder pressure sensor 105 are respectively connected to the ECU 106 for communication. Specifically, the hydrogen rail pressure sensor 104 is used to obtain rail pressure data in real time, and the cylinder pressure sensor 105 is used to obtain cylinder pressure data in real time; ECU 106 is used to receive rail pressure data and cylinder pressure data, and execute the rail pressure fluctuation control method of a hydrogen internal combustion engine proposed in the present invention.

[0036] Figure 2The following is an execution flow of the above method, which specifically includes the following steps:

[0037] Step S1, obtain the current working condition, and obtain the preset rail pressure P according to the working condition set and preset injection quantity m set .

[0038] Specifically, during the operation of the engine, based on the current operating conditions, the preset rail pressure P is read according to the map table. set and the preset injection amount m for the current cycle set .

[0039] Step S2, obtaining the current rail pressure data P rail 、Current cylinder pressure data P chamber and the current injection timing data t start .

[0040] Specifically, the hydrogen rail pressure sensor 104 and the cylinder pressure sensor 105 start to collect the rail pressure data P of each cylinder in real time. rail And cylinder pressure data P chamber Rail pressure and cylinder pressure signals are fed back to ECU 106 through sensors.

[0041] Step S3: according to the current rail pressure data P rail And cylinder pressure data P chamber , calculate the current injection flow rate.

[0042] Specifically, the injection flow rate is defined as: the mass flow rate of hydrogen injected into the combustion chamber 1031 through the injector 102 per unit time, represented by m, and the specific calculation formula is:

[0043]

[0044] In the formula, C d is the flow coefficient of the hydrogen injector, which is measured experimentally; A is the effective cross-sectional area of ​​the hydrogen injector nozzle, and ρ is the hydrogen density.

[0045] Step S4: according to the injection flow m and the current preset injection amount m set , calculate the current cylinder fluctuation coefficient σ m .

[0046] Specifically, the specific calculation formula of the cylinder fluctuation coefficient is:

[0047]

[0048] Step S5, determine the current cylinder fluctuation coefficient σ m Whether it exceeds the preset threshold σ target :

[0049] When the cylinder fluctuation coefficient σm Exceeding the preset threshold σ target When the current preset rail pressure P set Calculate the current rail pressure adjustment ΔP rail , and adjust the rail pressure ΔP according to the rail pressure rail Adjust the rail pressure of all cylinders and return to step S2;

[0050] When the cylinder fluctuation coefficient σ m Does not exceed the preset threshold σ target When the rail pressure of all cylinders is maintained, the process returns to step S1.

[0051] Among them, the rail pressure adjustment amount ΔP rail The specific calculation formula is:

[0052]

[0053] e rail =P set -P rail (4)

[0054] In the formula, K pi is the proportional gain of the i-th cylinder, indicating the degree of response of the system to the hydrogen injection stability error; K di is the differential gain of the i-th cylinder, indicating the degree of response of the system to the error change rate; i≤n, n is the total number of cylinders; e rail is the rail pressure error.

[0055] Furthermore, in step S5, according to the current cylinder fluctuation coefficient σ m , calculate the current cylinder injection timing adjustment amount Δt, and adjust the injection timing t according to the cylinder injection timing adjustment amount Δt start The adjusted injection timing is recorded in the ECU 106, and the process returns to step S1.

[0056] Among them, the specific calculation formula of the cylinder injection timing adjustment amount Δt is:

[0057] Δt=-K·(σ m -σ target ) (5)

[0058] Where K is the preset adjustment coefficient.

[0059] Injection timing t start Adjust according to the following formula:

[0060] t start =t start +Δt (6)

[0061] Furthermore, the present embodiment also provides a hydrogen internal combustion engine rail pressure fluctuation control device, including a memory, a processor, and a program stored in the memory. When the processor executes the program, one or more steps of the aforementioned method are implemented. The execution flow of each step of the specific execution process is basically the same and will not be repeated here.

[0062] Furthermore, this embodiment also provides a storage medium on which a program is stored. When the program is executed, one or more steps of the aforementioned method are implemented. The execution flow of each step in the specific execution process is basically the same and will not be repeated here.

[0063] The aforementioned hydrogen internal combustion engine rail pressure fluctuation control method and the device and storage medium based on the method can realize the hydrogen injection stability measurement and real-time feedback control of the hydrogen internal combustion engine based on rail pressure. Specifically, by real-time monitoring of rail pressure changes, combined with feedback control algorithms, the hydrogen injection flow rate and injection timing are optimized to ensure the stable operation of the hydrogen injector; by accurately adjusting the rail pressure, the injection fluctuation and multi-cylinder interference are reduced, the combustion stability, efficiency and emission performance of the hydrogen internal combustion engine are improved, and ultimately the overall performance and reliability of the engine are improved.

[0064] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for controlling rail pressure fluctuation of a hydrogen internal combustion engine, characterized in that: The following steps are involved: S1, obtaining a current operating condition, and obtaining a preset rail pressure and a preset fuel injection amount according to the operating condition; S2, obtaining current rail pressure data and cylinder pressure data; S3, calculating the current injection flow rate according to the rail pressure data and the cylinder pressure data; S4, calculating a current cylinder fluctuation coefficient according to the injection flow rate and the current preset injection amount; S5, when the cylinder fluctuation coefficient exceeds the preset threshold, the current rail pressure adjustment amount is calculated according to the current preset rail pressure, and the rail pressures of all cylinders are adjusted according to the rail pressure adjustment amount, and the process returns to S2.

2. The method for controlling rail pressure fluctuation of a hydrogen internal combustion engine according to claim 1, characterized in that: The injection flow rate is expressed as: Where m is the injection flow rate, C d is the pre-measured flow coefficient of the hydrogen injector, A is the effective cross-sectional area of ​​the hydrogen injector nozzle, ρ is the hydrogen density, P rail is the current rail pressure data, P chamber It is the current cylinder pressure data.

3. The method for controlling rail pressure fluctuation of a hydrogen internal combustion engine according to claim 2, characterized in that: The cylinder fluctuation coefficient is expressed as: In the formula, σ m is the cylinder fluctuation coefficient, m set It is the current preset injection amount.

4. The method for controlling rail pressure fluctuation of a hydrogen internal combustion engine according to claim 3, characterized in that: The rail pressure adjustment amount is expressed as: e rail =P set -P rail In the formula, ΔP rail is the rail pressure adjustment, K pi is the proportional gain of the i-th cylinder, K di is the differential gain of the i-th cylinder, i≤n, n is the total number of cylinders, e rail is the rail pressure error, P set The preset rail pressure.

5. The method for controlling rail pressure fluctuation of a hydrogen internal combustion engine according to claim 1, characterized in that: The control method further comprises: In S2, the current injection timing data is obtained simultaneously; In S5, the current cylinder injection timing adjustment amount is calculated according to the current cylinder fluctuation coefficient, and the injection timing is adjusted according to the cylinder injection timing adjustment amount.

6. The method for controlling rail pressure fluctuation of a hydrogen internal combustion engine according to claim 5, characterized in that: The cylinder injection timing adjustment amount is expressed as: Δt=-K·(σ m -s target ) Where Δt is the current cylinder injection timing adjustment, K is the preset adjustment coefficient, σ m is the cylinder fluctuation coefficient, σ target is the preset threshold.

7. The method for controlling rail pressure fluctuation of a hydrogen internal combustion engine according to claim 1, characterized in that: In S5 , when the cylinder fluctuation coefficient does not exceed the preset threshold, the rail pressures of all cylinders are maintained, and the process returns to S1 .

8. A rail pressure fluctuation control device for a hydrogen internal combustion engine, comprising a memory, a processor, and a program stored in the memory, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

9. A storage medium having a program stored thereon, characterized in that: When the program is executed, the method according to any one of claims 1 to 7 is implemented.

10. An injection system comprising a hydrogen rail, an injector mounted on the hydrogen rail, and a cylinder connected to the injector, wherein the cylinder comprises a combustion chamber, characterized in that: The system further comprises a hydrogen rail pressure sensor, a cylinder pressure sensor and an electronic control unit, wherein the hydrogen rail pressure sensor is mounted on the hydrogen rail, the cylinder pressure sensor is mounted on the cylinder, and the hydrogen rail pressure sensor and the cylinder pressure sensor are respectively connected to the electronic control unit for communication; The hydrogen rail pressure sensor is used to obtain rail pressure data in real time, and the cylinder pressure sensor is used to obtain cylinder pressure data in real time; The electronic control unit is used to receive the rail pressure data and the cylinder pressure data, and execute the rail pressure fluctuation control method for a hydrogen internal combustion engine as described in any one of claims 1 to 7.

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