A hydrogen and diesel dual fuel supply device and fuel injection method

Abstract

The present invention relates to a hydrogen and diesel dual fuel supply device and a fuel injection method, comprising a diesel supply system, a hydrogen supply system, and a dual fuel ECU electronic control module; the diesel supply system is connected to a fuel injector to supply diesel to an engine combustion chamber; the hydrogen supply system sprays hydrogen into the intake branch pipe to mix with air and then enter the engine combustion chamber; the dual fuel ECU electronic control module uses a self-developed dual fuel ECU as the control core, first determines the engine operating conditions, sprays the maximum hydrogen blending amount based on the maximum explosion pressure and the maximum exhaust temperature as the limiting conditions, obtains the original engine fuel injection amount under the current hydrogen blending amount according to the torque conservation control strategy, can realize accurate hydrogen diesel injection control and determine the maximum hydrogen blending amount range under various working conditions. The present invention does not change the overall structure of the diesel engine, is simple to operate, and is low in cost, and can realize low-carbon combustion of hydrogen and diesel dual fuels, so as to reduce carbon emissions and improve the performance of traditional diesel engines.

Description

Technical Field

[0001] The invention relates to the technical field of engine fuel supply systems, and in particular to a hydrogen and diesel dual-fuel supply device and a fuel injection method. Background Art

[0002] Traditional diesel engines burn fossil fuels, and the combustion products contain a large amount of carbon dioxide, in addition to a small amount of nitrogen oxides, nitric oxide, hydrocarbons and soot pollutants. As a tool that converts chemical energy into mechanical energy through combustion, internal combustion engines urgently need energy transformation to reduce carbon emissions and pollutants. Using hydrogen as an alternative fuel for internal combustion engines, the combustion product only produces water, which is an important measure to reduce carbon emissions, achieve sustainable development and carbon neutrality goals, and has high environmental significance.

[0003] Therefore, by installing a hydrogen injection system on a high-pressure common rail diesel engine, it is converted into a hydrogen and diesel dual-fuel engine, hydrogen is injected into the intake port, and a hydrogen and diesel dual-fuel supply device and fuel injection method are designed. This design combines the independently developed dual-fuel ECU electronic control module, and queries the fuel supply amount according to the torque conservation control strategy for the amount of hydrogen mixed under each working condition. By adjusting the required fuel supply and hydrogen supply under different working conditions, the diesel flame ignites the combustion of hydrogen, and the maximum explosion pressure and the maximum exhaust temperature limit the maximum hydrogen blending range, so as to reduce carbon emissions and improve the performance of traditional diesel engines, and provide a reference for the maximum hydrogen blending substitution rate range. Summary of the invention

[0004] The purpose of the present invention is to provide a hydrogen and diesel dual-fuel supply device and a fuel injection method, which adds an independent hydrogen supply system to the engine. The whole design scheme does not change the overall structure of the diesel engine, and has the characteristics of relatively simple operation, low cost and safe operation. With the dual-fuel ECU as the control core, the engine operating conditions are first judged, and the maximum hydrogen blending amount is injected based on the maximum explosion pressure and the maximum exhaust temperature as the limiting conditions. The original engine fuel injection amount under the current hydrogen blending amount is obtained according to the torque conservation control strategy, which can realize the precise injection control of diesel and hydrogen, and determine the maximum hydrogen blending amount range under various working conditions. The purpose of achieving low-carbon combustion of hydrogen and diesel dual fuels, reducing carbon emissions and improving the performance of traditional diesel engines is achieved.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A hydrogen and diesel dual fuel supply device and a fuel injection method, comprising a diesel supply system, wherein a fuel tank, a diesel filter, a high-pressure oil pump, a diesel mass flow meter and a high-pressure common rail are connected in sequence; the hydrogen supply system comprises a hydrogen bottle group, a pressure reducing gauge, a flame arrester, a hydrogen mass flow meter, a hydrogen rail and a hydrogen injection nozzle; a dual-fuel ECU electronic control module, wherein the ECU used is a dual-fuel LabECU integrated controller based on FPGA program calculation, wherein the engine operating condition is first determined by a crankshaft signal and a camshaft signal, and then the maximum hydrogen blending amount under this condition is injected with the maximum explosion pressure and the maximum exhaust temperature as limiting conditions, and the original engine fuel injection amount under the current hydrogen blending amount is obtained according to the torque conservation control strategy, so as to realize the precise injection control of diesel and hydrogen and determine the maximum hydrogen blending amount range under various conditions.

[0007] Preferably, the diesel supply system further includes a fuel supply pressure sensor, which can detect the pressure of diesel. The fuel supply pressure sensor is connected to the dual-fuel ECU electronic control module, and the electronic control module adjusts the injection amount according to the received real-time injection pressure. The diesel supply system also includes an injection solenoid valve, which is connected to the self-developed dual-fuel ECU electronic control module, and the dual-fuel ECU electronic control module can control the injection solenoid valve to open or close. The injection solenoid valve is used to control the start or stop of injection of the injector.

[0008] Preferably, the hydrogen supply system further comprises a hydrogen supply pressure sensor and a hydrogen supply temperature sensor, which can detect the pressure and temperature of hydrogen. The hydrogen supply pressure sensor and the hydrogen supply temperature sensor are connected to the dual-fuel ECU electronic control module, and the electronic control module adjusts the hydrogen injection amount according to the received real-time hydrogen supply pressure and temperature. The hydrogen supply system further comprises a hydrogen injection solenoid valve, which is connected to the independently developed dual-fuel ECU electronic control module, and the dual-fuel ECU electronic control module can control the hydrogen injection solenoid valve to open or close. The hydrogen injection solenoid valve is used to control the start or stop injection of the hydrogen injection nozzle.

[0009] Preferably, the diesel in the diesel supply system is directly injected into the cylinder using a high-pressure common rail.

[0010] As a preferred method, the hydrogen in the hydrogen supply system is injected in a multi-point sequential manner in the air inlet. In addition, in order to ensure that the experiment is carried out smoothly and safely, a safety alarm system is added to detect whether the use of hydrogen is safe in real time.

[0011] In the above technical solution, the present invention provides a hydrogen and diesel dual fuel supply device and a fuel injection method, which have the following beneficial effects:

[0012] 1. Add an independent hydrogen supply system to the engine. The whole design does not change the overall structure of the diesel engine. It has the characteristics of relatively simple operation, low cost and safe operation. The combustion of diesel mixed with hydrogen helps to reduce carbon emissions.

[0013] 2. Combined with the independently developed dual-fuel ECU electronic control system, by accurately controlling the oil supply and hydrogen supply, it can achieve precise injection control of diesel and hydrogen, as well as flexible switching between single-fuel and dual-fuel modes. The maximum hydrogen blending amount is injected with the maximum explosion pressure and the maximum exhaust temperature as the limiting conditions, and the maximum hydrogen blending amount range under various working conditions is determined to achieve the purpose of reducing carbon emissions and improving the performance of traditional diesel engines, as well as providing a reference for the maximum hydrogen blending substitution rate range.

[0014] In order to ensure the smooth and safe progress of the experiment, a safety alarm system was added to detect in real time whether the use of hydrogen is safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a hydrogen and diesel dual-fuel supply device provided by an example of the present invention.

[0016] Figure 2 It is a schematic diagram of a hydrogen and diesel dual-fuel fuel injection method provided by an example of the present invention.

[0017] Figure 1 The figure numbers are as follows: 1-hydrogen cylinder group; 2-first pressure reducing gauge; 3-first flame arrester; 4-second pressure reducing gauge; 5-hydrogen flow sensor; 6-hydrogen supply temperature sensor; 7-second flame arrester; 8-hydrogen supply pressure sensor; 9-hydrogen rail; 10-hydrogen injection solenoid valve; 11-hydrogen injection nozzle; 12-dual fuel ECU electronic control module; 13-fuel supply pressure sensor; 14 high pressure common rail; 15-diesel mass flow meter; 16-high pressure fuel pump; 17-diesel filter; 18-fuel tank; 19-engine speed sensor; 20-flywheel ring gear; 21-fuel injection solenoid valve; 22-fuel injection nozzle; 23-intake branch pipe; 24-combustion chamber; 25-exhaust branch pipe; 26-accelerator pedal position sensor. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0019] The present invention proposes a hydrogen and diesel dual-fuel supply device and a fuel injection method, which include a diesel supply system, a hydrogen supply system, and a dual-fuel ECU electronic control module 12.

[0020] The output end of the diesel supply system is connected to the fuel injector 22 and supplies fuel to the engine combustion chamber 24; the output end of the hydrogen supply system is connected to the jet nozzle 11 and supplies the mixed gas to the engine combustion chamber 24 after mixing with air at the intake branch pipe 23. The diesel supply system includes a fuel tank 18, a diesel filter 17, a high-pressure fuel pump 16, a diesel mass flow meter 16 and a high-pressure common rail 14 connected in sequence; the hydrogen supply system includes a hydrogen bottle group 1, a pressure reducing gauge 2, a flame arrester 3, a pressure reducing gauge 4, a hydrogen flow sensor 5, a flame arrester 7, a hydrogen rail 9, and a hydrogen nozzle 11 connected in sequence.

[0021] The dual-fuel ECU module 12 collects engine status signals such as the speed sensor 19 and the accelerator pedal position sensor 26 and sends them to the FPGA processor, and the control strategy in the host computer analyzes and processes the signals.

[0022] Furthermore, the speed and load are first fixed, and the current operating condition of the engine is determined by the crankshaft signal and the camshaft signal. The hydrogen supply valve is opened, and after the hydrogen supply pressure is stabilized, the dual-fuel mode is switched to gradually increase the hydrogen injection pulse width, and the hydrogen supply volume increases. According to the torque conservation control strategy, the total torque is equal to the sum of the hydrogen-substituted torque and the original engine torque. The ECU queries the original engine map according to the remaining required torque after hydrogen addition to obtain the required injection volume corresponding to each hydrogen addition volume under the current operating condition, and completes the injection control. The hydrogen addition volume is limited by the maximum explosion pressure and the maximum exhaust temperature. When the limit conditions are reached, the hydrogen addition volume under this operating condition is terminated, and then the hydrogen pulse width is gradually reduced to 0, the hydrogen supply valve is closed, and the next operating point is switched to repeat the above steps. This method can obtain the maximum hydrogen addition volume range under various operating conditions. Under this method, the maximum hydrogen substitution rate does not exceed 49.1% at low speed and low load, the maximum hydrogen substitution rate does not exceed 16.0% at low speed and high load, the maximum hydrogen substitution rate does not exceed 30.5% at high speed and low load, and the maximum hydrogen substitution rate does not exceed 14.0% at high speed and high load.

[0023] Furthermore, the dual-fuel ECU module 12 is connected to the fuel injection solenoid valve 21 and the hydrogen injection solenoid valve 10, the fuel injection solenoid valve 21 is connected to the fuel injector 22, and the hydrogen injection solenoid valve 10 is connected to the hydrogen injection nozzle 11. The dual-fuel ECU electronic control module 12 can control the opening or closing of the fuel injection solenoid valve 21 and the hydrogen injection solenoid valve 10; the fuel injection solenoid valve 21 is used to control the start injection or stop injection of the fuel injector 22; the hydrogen injection solenoid valve 10 is used to control the start injection or stop injection of the hydrogen injection nozzle 11; therefore, the dual-fuel ECU module 12 outputs the output control signal to the fuel injector 22, the hydrogen injection nozzle 11 and other actuators through the drive board control circuit to realize dual fuel supply or single fuel supply.

[0024] Furthermore, the diesel supply system also includes a fuel supply pressure sensor 13, which can detect the pressure of diesel and is connected to the dual-fuel ECU electronic control module 12. The dual-fuel ECU electronic control module 12 adjusts the injection amount according to the received real-time injection pressure.

[0025] Furthermore, the hydrogen supply system also includes a hydrogen supply pressure sensor 8 and a hydrogen supply temperature sensor 6, which can detect the pressure and temperature of the hydrogen in the pipeline, and are both connected to the dual-fuel ECU electronic control module 12, which adjusts the hydrogen injection amount according to the received real-time hydrogen supply pressure and temperature.

[0026] In order to ensure the smooth and safe progress of the experiment, a safety alarm system was added to detect in real time whether the use of hydrogen is safe.

Claims

1. A hydrogen and diesel dual fuel supply device, characterized in that: include: Diesel supply system, hydrogen supply system, dual-fuel ECU electronic control module; The diesel supply system is connected to the fuel injector to supply diesel to the engine combustion chamber; The hydrogen supply system sprays hydrogen into the intake manifold and mixes with air before entering the engine combustion chamber; The dual-fuel ECU electronic control module first determines the engine operating conditions, injects the maximum hydrogen blending amount based on the maximum explosion pressure and the maximum exhaust temperature as limiting conditions, and obtains the original engine fuel injection amount under the current hydrogen blending amount according to the torque conservation control strategy, so as to realize the precise injection control of diesel and hydrogen; The fuel injection method of the hydrogen and diesel dual fuel supply device comprises: (1) First, set the speed and load, determine the current operating condition of the engine based on the crankshaft signal and camshaft signal, and open the hydrogen supply valve; (2) After the hydrogen supply pressure stabilizes, switch to dual-fuel mode, gradually increase the hydrogen injection pulse width, and increase the hydrogen supply volume. The ECU calculates the total torque equal to the sum of the hydrogen replacement torque and the original engine torque. The ECU obtains the required fuel injection amount corresponding to each hydrogen blending amount under the current working condition by querying the original engine map based on the remaining torque required after hydrogen blending, thereby achieving precise injection control of diesel and hydrogen. (3) The addition of hydrogen is limited by the maximum explosion pressure and the maximum exhaust temperature. When the limit conditions are reached, the addition of hydrogen under this operating condition is terminated. Then, the hydrogen pulse width is gradually reduced to 0, the hydrogen supply valve is closed, and the next operating point is switched to repeat the above steps.

2. A hydrogen and diesel dual fuel supply device according to claim 1, characterized in that: The hydrogen supply system comprises a hydrogen cylinder group (1), a first pressure reducing valve (2), a first flame arrester (3), a second pressure reducing valve (4), a hydrogen mass flow meter (5), a second flame arrester (7), a hydrogen rail (9) and a hydrogen nozzle (11) which are connected in sequence; the hydrogen cylinder group (1) is used to store hydrogen; the first pressure reducing valve (2) and the second pressure reducing valve (4) are used to reduce the pressure of high-pressure hydrogen in the hydrogen cylinder group; the first flame arrester (3) and the second flame arrester (7) are used to prevent the flame of hydrogen from spreading in the pipeline to prevent backfire and avoid explosion; the hydrogen mass flow meter (5) is used to read the mass of hydrogen injected into the cylinder in each cycle; the hydrogen rail (9) is a five-way valve composed of an air inlet and four air outlets, the air inlet of which is connected to the hydrogen nozzle (11); the hydrogen nozzle (11) is installed at the air intake branch pipe (23), and the hydrogen mixed with air is mixed into the engine combustion chamber (24).

3. A hydrogen and diesel dual fuel supply device according to claim 2, characterized in that: The hydrogen supply system further comprises a hydrogen supply pressure sensor (8) and a hydrogen supply temperature sensor (6) for measuring real-time hydrogen supply pressure and temperature. The hydrogen supply pressure sensor (8) and the hydrogen supply temperature sensor (6) are connected to the dual-fuel ECU electronic control module (12). The dual-fuel ECU electronic control module (12) adjusts the hydrogen injection amount according to the received real-time hydrogen supply pressure and temperature.

4. A hydrogen and diesel dual fuel supply device according to claim 2, characterized in that: The hydrogen supply system further comprises a hydrogen injection solenoid valve (10) connected to the dual-fuel ECU electronic control module (12), and the dual-fuel ECU electronic control module (12) starts or stops the hydrogen injection nozzle (11) by controlling the hydrogen injection solenoid valve (10) to open or close.

5. A hydrogen and diesel dual fuel supply device according to claim 2, characterized in that: In the hydrogen supply system, hydrogen is injected in a multi-point sequential manner in the air intake passage.

6. A hydrogen and diesel dual fuel supply device according to claim 2, characterized in that: It also includes a safety alarm system for real-time detection of whether hydrogen use is safe.

7. A hydrogen and diesel dual fuel supply device according to claim 1, characterized in that: The diesel supply system comprises a fuel tank (18), a diesel filter (17), a high-pressure fuel pump (16), a diesel mass flow meter (15) and a high-pressure common rail (14) which are connected in sequence; the fuel tank (18) is used to store diesel; the diesel filter (17) is used to filter out solid residues contained in the diesel; the high-pressure fuel pump (16) transmits the diesel in the fuel tank to the high-pressure common rail at high pressure; the diesel mass flow meter (15) is used to read the mass of diesel injected into the cylinder in each cycle; the high-pressure common rail (14) directly or indirectly forms a constant high-pressure fuel through the common rail, distributes it to each diesel fuel injector (22) of the engine, and injects the diesel into the combustion chamber (24).

8. A hydrogen and diesel dual fuel supply device according to claim 7, characterized in that: The diesel supply system further comprises a fuel supply pressure sensor (13) for detecting the pressure of diesel, the fuel supply pressure sensor (13) being connected to the dual-fuel ECU electronic control module (12), and the dual-fuel ECU electronic control module (12) adjusting the fuel injection amount according to the received real-time fuel injection pressure; the diesel supply system further comprises a fuel injection solenoid valve (21) being connected to the dual-fuel ECU electronic control module (12), and the dual-fuel ECU electronic control module (12) being able to control the fuel injection solenoid valve (21) to be opened or closed; the fuel injection solenoid valve (21) is used to control the fuel injection nozzle (22) to start injection or stop injection.

9. A hydrogen and diesel dual fuel supply device according to claim 7, characterized in that: The diesel fuel in the diesel fuel supply system is directly injected into the cylinder using a high-pressure common rail.

10. A hydrogen and diesel dual fuel supply device according to any one of claims 1 to 9, characterized in that: The ECU used in the dual-fuel ECU electronic control module (12) is a dual-fuel LabECU integrated controller based on FPGA program calculation. It collects engine status signals such as a speed sensor (19) and an accelerator pedal position sensor (25) and sends them to an FPGA processor. The control strategy in the host computer analyzes and processes the signals, and then outputs the output control signals to the fuel injector (22) and the hydrogen injector (11) through the driver board control circuit to control the operation of the engine.

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