Dual-fuel injection system, control method, control device and vehicle

Abstract

The invention belongs to the technical field of vehicles, and discloses a dual-fuel injection system, a control method, a control device and a vehicle, in the working process of an engine, the dual-fuel injection system is controlled to adjust the injection pressure of first fuel according to the rotating speed and torque of the engine, and it is guaranteed that the injection amount of the first fuel meets the basic requirements of engine operation; and P1 is limited to be larger than P2, so that carbon deposition at the injection hole can be washed away when the first fuel is injected, the injection hole is prevented from being blocked, and the first fuel injection channel can normally inject the first fuel into the combustion chamber. According to the dual-fuel injection system control method, waste of the first fuel can be avoided, and the economical efficiency of engine operation is improved; and meanwhile, the influence of first fuel injection on the performance of the engine can be reduced as much as possible on the premise that carbon deposition at the injection holes is flushed away.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a dual-fuel injection system, a control method, a control device and a vehicle. Background Art

[0002] The injection end of the dual-fuel injector directly extends into the combustion chamber. The dual-fuel injector is used to inject two fuels into the combustion chamber, one of which is the pilot fuel and the other is the main fuel. The pilot fuel is used to ignite the main fuel. When the pilot fuel is gasoline or diesel, the injection end is kept at high temperature for a long time, and the injection hole used to inject the pilot fuel is small in diameter, which is very easy to accumulate carbon. In order to improve fuel economy, the injection pressure is usually very low, so that as the carbon deposits increase, the carbon deposits will block the injection holes used to inject the pilot fuel, causing the dual-fuel injector to fail to work properly.

[0003] In order to prevent carbon deposits from clogging the nozzle holes for injecting pilot fuel, the prior art fuel engine proposes to calculate the amount of carbon deposits in the fuel injector in real time, and when the amount of carbon deposits exceeds a set value, use the maximum fuel injection pressure to inject fuel once, thereby clearing the carbon deposits at the nozzle holes through a larger fuel flow rate.

[0004] In actual application, it was found that the fuel consumption was high, which reduced the economic performance of the engine; the noise was loud, which reduced the NVH performance of the engine. Summary of the invention

[0005] The object of the present invention is to provide a dual-fuel injection system, a control method, a control device and a vehicle, which can ensure the normal operation of the dual-fuel injection system while removing carbon deposits.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A dual fuel injection system control method, wherein the fuel injected by the dual fuel injection system includes a first fuel, wherein the first fuel is a carbon fuel that plays an ignition role, and the dual fuel injection system has a carbon deposit removal mode and a normal working mode. The dual fuel injection system control method includes the following steps:

[0008] During the operation of the engine, controlling the dual fuel injection system to adjust the injection pressure of the first fuel according to the speed and torque of the engine;

[0009] When it is determined that the dual-fuel injection system needs to be cleaned of carbon deposits, switching the dual-fuel injection system from the normal working mode to the carbon deposit cleaning mode;

[0010] When the engine speed and torque are the same, the injection pressure of the first fuel when the dual-fuel injection system works in the carbon deposit removal mode is P1, and the injection pressure of the first fuel when the dual-fuel injection system works in the normal working mode is P2, P1>P2.

[0011] As an implementation scheme of the dual fuel injection system control method, the dual fuel injection system control method further includes the following steps:

[0012] The duration of the engine operating under the high-load condition is accumulated, and when the accumulated duration of the engine operating under the high-load condition reaches a preset duration, it is determined that the dual-fuel injection system needs to be cleaned of carbon deposits.

[0013] As an implementable embodiment of the dual fuel injection system control method, when the duration for which the dual fuel injection system operates in the carbon deposit removal mode reaches a preset removal duration, the dual fuel injection system is switched to the normal operation mode.

[0014] As an implementation scheme of the dual fuel injection system control method, the injection pressure P1 of the first fuel when the dual fuel injection system operates in the carbon deposit removal mode is obtained by the following steps:

[0015] Based on a first correspondence between the engine speed, the engine torque and the injection pressure P1 of the first fuel when the engine operates under the high-load condition for a preset clearing time, querying the actual engine speed and the actual engine torque to determine the injection pressure P1 of the first fuel;

[0016] The injection pressure P2 of the first fuel when the dual fuel injection system operates in the normal working mode is obtained by the following steps:

[0017] Based on the second corresponding relationship between the engine speed, the engine torque and the injection pressure P2 of the first fuel, the injection pressure P2 of the first fuel is determined by looking up the actual engine speed and the actual engine torque.

[0018] As an implementation scheme of the dual fuel injection system control method, the fuel injected by the dual fuel injection system further includes a second fuel;

[0019] When the dual-fuel injection system is in the carbon deposit removal mode, the displacement of the second fuel pump for supplying the second fuel in the dual-fuel injection system is adjusted according to the injection pressure of the first fuel to adjust the injection pressure of the second fuel so that the pressure difference between the injection pressure of the first fuel and the injection pressure of the second fuel is within a preset pressure difference range;

[0020] When the dual-fuel injection system is in the normal operating mode, the pressure regulating unit in the second fuel supply device is controlled to operate according to the injection pressure of the first fuel to adjust the injection pressure of the second fuel so that the pressure difference between the injection pressure of the first fuel and the injection pressure of the second fuel is within a preset pressure difference range.

[0021] In order to achieve the above object, the present invention further provides a dual fuel injection system, using the dual fuel injection system control method described in any of the above schemes, the dual fuel injection system comprising:

[0022] a fuel injector having a first fuel injection passage for injecting a first fuel into the combustion chamber;

[0023] The first fuel supply device includes a first fuel pump and a first fuel storage unit. The inlet of the first fuel pump is connected to the first fuel storage unit, the outlet of the first fuel pump is connected to the inlet of the first fuel injection channel, and the first fuel pump is a variable pump.

[0024] As an implementation scheme of the dual fuel injection system, the first fuel supply device further comprises a first fuel pressure detection unit for detecting the outlet pressure of the first fuel pump, and the fuel injector has a second fuel injection passage for injecting a second fuel into the combustion chamber;

[0025] The dual fuel injection system further comprises:

[0026] The second fuel supply device includes a second fuel pump, a second fuel storage unit and a pressure regulating unit. The inlet of the second fuel pump is connected to the second fuel storage unit, and the outlet of the second fuel pump is connected to the inlet of the second fuel injection channel through the pressure regulating unit. The second fuel pump is a variable pump, and the pressure regulating unit is used to adjust the pressure of the second fuel delivered to the second fuel injection channel according to the detection result of the first fuel pressure detection unit.

[0027] As an implementation scheme of the dual fuel injection system, the first fuel pump is connected to the inlet of the first fuel injection channel through the first fuel rail, and the pressure regulating unit is connected to the inlet of the second fuel injection channel through the second fuel rail;

[0028] The first fuel supply device further comprises:

[0029] a first pressure-limiting valve, wherein the inlet of the first fuel injection passage is connected to the first fuel storage unit via the first pressure-limiting valve;

[0030] A second pressure-limiting valve, wherein the inlet of the second pressure-limiting valve is connected to the inlet of the first pressure-limiting valve through a control switch valve, the outlet of the second pressure-limiting valve is connected to the outlet of the first pressure-limiting valve, and the opening pressure of the second pressure-limiting valve is greater than the opening pressure of the first pressure-limiting valve.

[0031] In order to achieve the above object, the present invention further provides a dual fuel injection system control device, which is used to control the dual fuel injection system described in any of the above schemes to execute the dual fuel injection system control method described in any of the above schemes, and the dual fuel injection system control device includes:

[0032] A determination module, used for determining whether the dual fuel injection system needs to be cleaned of carbon deposits;

[0033] A first control module, configured to control the dual-fuel injection system to execute the carbon deposit removal mode when the dual-fuel injection system needs to remove carbon deposits;

[0034] The second control module is used to control the dual fuel injection system to execute the normal working mode when the dual fuel injection system does not need to remove carbon deposits.

[0035] In order to achieve the above object, the present invention also provides a vehicle, comprising the above dual fuel injection system control device.

[0036] Beneficial effects of the present invention: The dual-fuel injection system, control method, control device and vehicle provided by the present invention, during the operation of the engine, control the dual-fuel injection system to adjust the injection pressure of the first fuel according to the engine speed and torque, to ensure that the injection amount of the first fuel meets the basic requirements of the engine operation, and by limiting P1>P2, the carbon deposits at the injection hole can be flushed away during the injection of the first fuel to avoid clogging of the injection hole, so that the first fuel injection channel can normally inject the first fuel into the combustion chamber.

[0037] The dual-fuel injection system control method can avoid the waste of the first fuel and improve the economy of engine operation; at the same time, it can reduce the influence of the first fuel injection on the engine performance as much as possible under the premise of ensuring that the carbon deposits at the injection hole are flushed away. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic diagram of the principle of a dual fuel injection system provided by an embodiment of the present invention;

[0039] Figure 2 It is a flow chart of a dual fuel injection system control method provided by an embodiment of the present invention.

[0040] In the figure:

[0041] 1. First fuel supply device; 11. First fuel storage unit; 12. First fuel pump; 13. First fuel filter; 14. First fuel rail; 15. First fuel pressure detection unit; 16. Control switch valve; 17. First pressure limiting valve; 18. Second pressure limiting valve;

[0042] 2. Second fuel supply device; 21. Second fuel storage unit; 22. Second fuel pump; 23. Second fuel filter; 24. Second fuel rail; 25. Second fuel pressure detection unit; 26. Pressure regulating unit;

[0043] 3. Fuel injector;

[0044] 4. Intake passage; 5. Exhaust passage; 6. Phase sensor; 7. Accelerator pedal; 8. Dual fuel injection system control device. DETAILED DESCRIPTION

[0045] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0046] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0048] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0049] like Figure 1 As shown, an embodiment of the present invention provides a dual fuel injection system, including a fuel injector 3 and a first fuel supply device 1, wherein the fuel injector 3 has a first fuel injection channel for injecting a first fuel into a combustion chamber of the engine; the first fuel supply device 1 includes a first fuel pump 12 and a first fuel storage unit 11, the inlet of the first fuel pump 12 is connected to the first fuel storage unit 11, the outlet of the first fuel pump 12 is connected to the inlet of the first fuel injection channel, and the first fuel pump 12 is a variable pump. The above-mentioned first fuel is a carbon-containing fuel that plays an ignition role. Exemplarily, the first fuel is fuel oil, such as diesel or gasoline. In other embodiments, the above-mentioned first fuel can also be dimethyl ether.

[0050] The combustion chamber is selectively connected or disconnected with the intake passage 4 through the intake valve, and selectively connected or disconnected with the exhaust passage 5 through the exhaust valve. A phase sensor 6 is installed on the engine, and the phase sensor 6 is used to detect the valve timing of the engine. The valve timing is the crankshaft angle corresponding to the moment when the intake valve and exhaust valve of the engine are opened and closed according to the working cycle of the engine. It is called the valve timing phase angle. When the valve timing phase angle is determined to be inaccurate according to the detection signal of the phase sensor 6, the instrument light on the vehicle is lit to indicate engine failure.

[0051] The accelerator pedal 7 on the vehicle is used to control the opening of the throttle valve of the engine to control the power output of the engine.

[0052] An embodiment of the present invention also provides a dual-fuel injection system control method, which is used for the above-mentioned dual-fuel injection system. The dual-fuel injection system has a carbon deposit removal mode and a normal working mode. When the engine speed and torque are the same, when the dual-fuel injection system works in the carbon deposit removal mode, the injection pressure of the first fuel is P1, and when the dual-fuel injection system works in the normal working mode, the injection pressure of the first fuel is P2, and P1>P2.

[0053] The dual fuel injection system control method comprises the following steps:

[0054] During the operation of the engine, the dual fuel injection system is controlled to adjust the injection pressure of the first fuel according to the speed and torque of the engine;

[0055] When it is determined that the dual-fuel injection system needs to be cleaned of carbon deposits, the dual-fuel injection system is controlled to switch from a normal working mode to a carbon deposit cleaning mode.

[0056] Specifically, the injection pressure of the first fuel is adjusted by adjusting the displacement of the first fuel pump 12. When the dual fuel injection system operates in the normal working mode, the injection pressure P2 of the first fuel and the displacement of the first fuel pump 12 correspond one to one.

[0057] The dual-fuel injection system control method controls the dual-fuel injection system to adjust the injection pressure of the first fuel according to the engine speed and torque during engine operation to ensure that the injection amount of the first fuel meets the basic requirements of engine operation, and by limiting P1>P2, the carbon deposits at the injection hole can be flushed away during the injection of the first fuel to avoid the injection hole being blocked, so that the first fuel injection channel can normally inject the first fuel into the combustion chamber.

[0058] The dual-fuel injection system control method can avoid the waste of the first fuel and improve the economy of engine operation; at the same time, it can reduce the influence of the first fuel injection on the engine performance as much as possible under the premise of ensuring that the carbon deposits at the injection hole are flushed away.

[0059] In some embodiments, the dual fuel injection system control method further includes the following steps:

[0060] The duration of the engine operating under the high-load condition is accumulated. When the accumulated duration of the engine operating under the high-load condition is greater than or equal to a preset duration, it is determined that the dual-fuel injection system needs to be cleaned of carbon deposits.

[0061] When the engine is in medium load, low load or idle condition, the temperature in the combustion chamber is relatively low and carbon deposits are not easy to form. Therefore, it is determined whether the accumulated time of the engine working under high load condition is greater than or equal to the preset time to determine whether the dual fuel injection system needs to be cleaned of carbon deposits.

[0062] The cumulative duration of the engine working under high-load conditions refers to the total duration of the engine working under high-load conditions from the completion of one carbon deposit removal mode to the start of the next carbon deposit removal mode of the dual-fuel injection system. It can be that the duration of the engine working under high-load conditions once reaches the preset duration, or it can be that the duration of the engine working under high-load conditions once does not reach the preset duration, but the sum of the duration of the engine working under high-load conditions multiple times reaches the preset duration.

[0063] The above-mentioned preset time is determined through repeated tests and will not be specifically limited here.

[0064] It should be noted that the high-load condition of the engine is determined based on the engine speed and torque. Specifically, if the ratio of the current torque of the engine to the maximum torque of the engine at the current speed is not less than the preset ratio, the engine is in a high-load condition. Exemplarily, the preset ratio is 90%, and the maximum torque of the engine at the current speed is the torque corresponding to the current speed of the engine obtained by querying the external characteristic curve between the speed and torque of the engine.

[0065] In some embodiments, the injection pressure P1 of the first fuel when the dual fuel injection system operates in the carbon deposit removal mode is obtained by the following steps:

[0066] Based on the first correspondence between the engine speed, the engine torque and the injection pressure P1 of the first fuel when the engine operates under high load conditions for a preset clearing time, the injection pressure P1 of the first fuel is determined by querying the actual engine speed and the actual engine torque.

[0067] It should be noted that the first corresponding relationship may be a map or a data table determined through multiple repeated tests, and is not specifically limited here.

[0068] The injection pressure P2 of the first fuel when the dual fuel injection system works in the normal working mode is obtained by the following steps:

[0069] Based on the second corresponding relationship between the engine speed, the engine torque and the injection pressure P2 of the first fuel, the injection pressure P2 of the first fuel is determined by looking up the actual engine speed and the actual engine torque.

[0070] It should be noted that the second corresponding relationship may be a map or a data table determined through multiple repeated tests, and is not specifically limited here.

[0071] The second fuel injected by the dual-fuel injection system is different from the first fuel. The second fuel may be natural gas, methanol, etc. At this time, the first fuel is used to ignite the second fuel.

[0072] The first fuel supply device 1 further includes a first fuel pressure detection unit 15 for detecting the outlet pressure of the first fuel pump 12, and the fuel injector 3 has a second fuel injection passage for injecting a second fuel into the combustion chamber.

[0073] The dual fuel injection system also includes a second fuel supply device 2, which includes a second fuel pump 22, a second fuel storage unit 21 and a pressure regulating unit 26. The inlet of the second fuel pump 22 is connected to the second fuel storage unit 21, and the outlet of the second fuel pump 22 is connected to the inlet of the second fuel injection channel through the pressure regulating unit 26. The second fuel pump 22 is a variable pump, and the pressure regulating unit 26 is used to adjust the pressure of the second fuel delivered to the second fuel injection channel according to the detection result of the first fuel pressure detection unit 15.

[0074] Exemplarily, the first fuel pressure detection unit 15 is a pressure sensor, and the pressure regulating unit 26 is an electromagnetic pressure reducing valve, which is convenient for adjusting the pressure of the second fuel delivered to the second fuel injection channel according to the detection result of the first fuel pressure detection unit 15.

[0075] Taking the first fuel as diesel and the second fuel as natural gas as an example, the first fuel storage unit 11 is a fuel tank, the second fuel storage unit 21 is an LNG gas cylinder, the first fuel pump 12 is a high-pressure oil pump, and the second fuel pump 22 is an LNG booster pump.

[0076] When the dual-fuel injection system is in normal working mode, the pressure regulating unit 26 in the second fuel supply device 2 is controlled to operate according to the injection pressure of the first fuel to adjust the injection pressure of the second fuel so that the pressure difference between the injection pressure of the first fuel and the injection pressure of the second fuel is within a preset pressure difference range.

[0077] The pressure regulating unit 26 adjusts the pressure of the second fuel delivered to the second fuel injection channel according to the detection result of the first fuel pressure detection unit 15, so that the injection pressure delivered to the second fuel follows the injection pressure change of the first fuel, and the injection pressure of the second fuel and the injection pressure of the first fuel maintain a stable pressure difference, thereby ensuring the combustion stability in the combustion chamber.

[0078] When the dual-fuel injection system is in the carbon deposit removal mode, since P1 is greater than P2 when the engine speed and torque are the same, the pressure regulating unit 26 may still fail to meet the injection pressure requirement for the second fuel when it is at the maximum opening, that is, it is impossible to keep the injection pressure of the first fuel and the injection pressure of the second fuel within the preset pressure difference range. Replacing the pressure regulating unit 26 will increase the cost and reduce the control accuracy of the injection pressure of the second fuel. For this reason, when the dual-fuel injection system is in the carbon deposit removal mode, the displacement of the second fuel pump 22 used to supply the second fuel in the dual-fuel injection system is adjusted according to the injection pressure of the first fuel to adjust the injection pressure of the second fuel so that the pressure difference between the injection pressure of the first fuel and the injection pressure of the second fuel is within the preset pressure difference range.

[0079] In some embodiments, the first fuel pump 12 is in communication with an inlet of the first fuel injection passage through the first fuel rail 14 , and the pressure regulating unit 26 is in communication with an inlet of the second fuel injection passage through the second fuel rail 24 .

[0080] During operation of the dual fuel injection system, the first fuel rail 14 prevents the air pressure in the combustion chamber from affecting the outlet pressure of the first fuel pump 12 , and the second fuel rail 24 prevents the air pressure in the combustion chamber from affecting the outlet pressure of the second fuel pump 22 .

[0081] In some embodiments, the first fuel supply device 1 also includes a first pressure-limiting valve 17 and a second pressure-limiting valve 18, and the inlet of the first fuel injection channel is connected to the first fuel storage unit 11 through the first pressure-limiting valve 17; the inlet of the second pressure-limiting valve 18 is connected to the inlet of the first pressure-limiting valve 17 through the control switch valve 16, and the outlet of the second pressure-limiting valve 18 is connected to the outlet of the first pressure-limiting valve 17, and the opening pressure of the second pressure-limiting valve 18 is greater than the opening pressure of the first pressure-limiting valve 17.

[0082] When the dual fuel injection system is in normal working mode, the first pressure limiting valve 17 is operative to prevent the outlet pressure of the first fuel injection channel from being too high, thereby improving the injection pressure accuracy of the first fuel and correspondingly improving the injection pressure accuracy of the second fuel.

[0083] When the dual fuel injection system is in the carbon deposit removal mode, due to the same engine speed and torque, P1 is greater than P2. Therefore, the control switch valve 16 is closed, so that the first pressure limiting valve 17 does not work. At this time, the second pressure limiting valve 18 works to avoid excessive outlet pressure of the first fuel injection channel.

[0084] Exemplarily, the control switch valve 16 is a solenoid switch valve.

[0085] In some embodiments, when the operating time of the dual fuel injection system in the carbon deposit cleaning mode reaches a preset cleaning time, the dual fuel injection system is switched to the normal operating mode.

[0086] When the cumulative working time of the engine under high load conditions is greater than or equal to the preset time, the dual-fuel injection system is switched from the normal working mode to the carbon deposit removal mode. Therefore, the above-mentioned preset removal time is based on the premise that the working time of the engine under high load conditions is equal to the preset time. The preset removal time is the time it takes to remove the carbon deposits near the injection hole determined through multiple repeated tests. This is a known value and is not specifically limited here.

[0087] When the working time of the dual-fuel injection system in the carbon deposit removal mode reaches the preset removal time, it means that the carbon deposit removal is completed, the accumulated time of the engine working under the high load condition is reset, and the time of the engine working under the high load condition is accumulated again.

[0088] In some embodiments, the dual fuel injection system further includes a second fuel pressure detection unit 25, which is used to detect the outlet pressure of the second fuel pump 22. Exemplarily, the second fuel pressure detection unit 25 is a pressure sensor.

[0089] In some embodiments, a first fuel filter 13 is disposed between the first fuel storage unit 11 and the first fuel pump 12 , and a second fuel filter 23 is disposed between the second fuel pump 22 and the pressure regulating unit 26 .

[0090] When the first fuel is fuel oil, the first fuel filter 13 is a fuel oil filter, and when the second fuel is natural gas, the second fuel filter 23 is a fuel gas filter.

[0091] Figure 2 is a flow chart of a dual fuel injection system control method provided by a preferred embodiment. Figure 2 As shown, the dual fuel injection system control method includes the following steps:

[0092] S10, during the operation of the engine in the normal working mode, the cumulative time T1 of the engine working under the high load condition;

[0093] S20, determine whether T1 is greater than or equal to the preset time length T0, if so, execute S30, if not, return to S10;

[0094] S30, controlling the dual fuel injection system to switch to a carbon deposit removal mode;

[0095] S40, determining whether the working time T2 of the dual fuel injection system working in the carbon deposit removal mode reaches the preset removal time T3, if yes, executing S50, if no, returning to S40;

[0096] S50: Control the dual fuel injection system to switch to a normal working mode, and clear the accumulated working time of the engine under the high load condition to zero.

[0097] An embodiment of the present invention also provides a dual fuel injection system control device, which is used to control the above-mentioned dual fuel injection system to execute the above-mentioned dual fuel injection system control method. The above-mentioned pressure regulating unit 26, the first fuel pump 12, the second fuel pump 22, the first fuel pressure detection unit 15, the second fuel pressure detection unit 25, and the control switch valve 16 are all electrically connected to the dual fuel injection system control device 8.

[0098] The dual fuel injection system control device 8 includes a determination module, a first control module and a second control module, wherein the determination module is used to determine whether the dual fuel injection system needs to perform carbon deposit removal; the first control module is used to control the dual fuel injection system to execute a carbon deposit removal mode when the dual fuel injection system needs to perform carbon deposit removal; the second control module is used to control the dual fuel injection system to execute a normal working mode when the dual fuel injection system does not need to perform carbon deposit removal.

[0099] When the dual-fuel injection system operates in the carbon deposit removal mode, the dual-fuel injection system is controlled to adjust the injection pressure of the first fuel according to the engine speed and torque to ensure that the injection amount of the first fuel meets the basic requirements of the engine operation, and by limiting P1>P2, the carbon deposits at the injection hole can be flushed away during the injection of the first fuel to avoid clogging of the injection hole, so that the first fuel injection channel can normally inject the first fuel into the combustion chamber.

[0100] The dual fuel injection system control device 8 can avoid the waste of the first fuel and improve the economy of engine operation; at the same time, it can reduce the influence of the first fuel injection on the engine performance as much as possible under the premise of flushing away the carbon deposits at the injection hole.

[0101] An embodiment of the present invention further provides a vehicle, comprising the dual-fuel injection system control device 8 described above. The vehicle has the same technical effects as the dual-fuel injection system control device 8 described above, and will not be repeated here.

[0102] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A dual fuel injection system control method, characterized in that: The fuel injected by the dual-fuel injection system includes a first fuel, the first fuel is a carbon-containing fuel that plays an ignition role, the dual-fuel injection system has a carbon deposit removal mode and a normal working mode, and the dual-fuel injection system control method includes the following steps: During the operation of the engine, controlling the dual fuel injection system to adjust the injection pressure of the first fuel according to the speed and torque of the engine; When it is determined that the dual-fuel injection system needs to be cleaned of carbon deposits, controlling the dual-fuel injection system to switch from the normal working mode to the carbon deposit cleaning mode; When the engine speed and torque are the same, the injection pressure of the first fuel when the dual-fuel injection system works in the carbon deposit removal mode is P1, and the injection pressure of the first fuel when the dual-fuel injection system works in the normal working mode is P2, P1>P2.

2. The dual fuel injection system control method according to claim 1, characterized in that: The dual fuel injection system control method further comprises the following steps: The duration of the engine operating under the high-load condition is accumulated, and when the accumulated duration of the engine operating under the high-load condition reaches a preset duration, it is determined that the dual-fuel injection system needs to be cleaned of carbon deposits.

3. The dual fuel injection system control method according to claim 2, characterized in that: When the duration for which the dual-fuel injection system operates in the carbon deposit removal mode reaches a preset removal duration, the dual-fuel injection system is switched to the normal operation mode.

4. The dual fuel injection system control method according to claim 3, characterized in that: The injection pressure P1 of the first fuel when the dual-fuel injection system operates in the carbon deposit removal mode is obtained by the following steps: Based on a first correspondence between the engine speed, the engine torque and the injection pressure P1 of the first fuel when the engine operates under the high-load condition for a preset clearing time, querying the actual engine speed and the actual engine torque to determine the injection pressure P1 of the first fuel; The injection pressure P2 of the first fuel when the dual fuel injection system operates in the normal working mode is obtained by the following steps: Based on the second corresponding relationship between the engine speed, the engine torque and the injection pressure P2 of the first fuel, the injection pressure P2 of the first fuel is determined by looking up the actual engine speed and the actual engine torque.

5. The dual fuel injection system control method according to claim 1, characterized in that: The dual fuel injection system is a dual fuel injection system, and the fuel injected by the dual fuel injection system also includes a second fuel; When the dual-fuel injection system is in the carbon deposit removal mode, the displacement of a second fuel pump (22) in the dual-fuel injection system for supplying a second fuel is adjusted according to the injection pressure of the first fuel to adjust the injection pressure of the second fuel so that the pressure difference between the injection pressure of the first fuel and the injection pressure of the second fuel is within a preset pressure difference range; When the dual fuel injection system is in the normal working mode, the pressure regulating unit (26) in the second fuel supply device (2) is controlled to operate according to the injection pressure of the first fuel to adjust the injection pressure of the second fuel so that the pressure difference between the injection pressure of the first fuel and the injection pressure of the second fuel is within a preset pressure difference range.

6. Dual fuel injection system, characterized in that, The dual fuel injection system control method according to any one of claims 1 to 5 is adopted, wherein the dual fuel injection system comprises: A fuel injector (3), wherein the fuel injector (3) has a first fuel injection passage for injecting a first fuel into a combustion chamber; A first fuel supply device (1) comprises a first fuel pump (12) and a first fuel storage unit (11), wherein the inlet of the first fuel pump (12) is connected to the first fuel storage unit (11), the outlet of the first fuel pump (12) is connected to the inlet of the first fuel injection channel, and the first fuel pump (12) is a variable displacement pump.

7. The dual fuel injection system according to claim 6, characterized in that: The first fuel supply device (1) further comprises a first fuel pressure detection unit (15) for detecting the outlet pressure of the first fuel pump (12), and the fuel injector (3) has a second fuel injection passage for injecting a second fuel into the combustion chamber; The dual fuel injection system further comprises: The second fuel supply device (2) comprises a second fuel pump (22), a second fuel storage unit (21) and a pressure regulating unit (26); the inlet of the second fuel pump (22) is connected to the second fuel storage unit (21); the outlet of the second fuel pump (22) is connected to the inlet of the second fuel injection channel via the pressure regulating unit (26); the second fuel pump (22) is a variable pump; the pressure regulating unit (26) is used to adjust the pressure of the second fuel delivered to the second fuel injection channel according to the detection result of the first fuel pressure detection unit (15).

8. The dual fuel injection system according to claim 7, characterized in that: The first fuel pump (12) is connected to the inlet of the first fuel injection channel through the first fuel rail (14), and the pressure regulating unit (26) is connected to the inlet of the second fuel injection channel through the second fuel rail (24); The first fuel supply device (1) further comprises: a first pressure limiting valve (17), wherein the inlet of the first fuel injection passage is connected to the first fuel storage unit (11) via the first pressure limiting valve (17); A second pressure-limiting valve (18), wherein the inlet of the second pressure-limiting valve (18) is connected to the inlet of the first pressure-limiting valve (17) via a control switch valve (16), the outlet of the second pressure-limiting valve (18) is connected to the outlet of the first pressure-limiting valve (17), and the opening pressure of the second pressure-limiting valve (18) is greater than the opening pressure of the first pressure-limiting valve (17).

9. A dual fuel injection system control device, characterized in that: The dual fuel injection system according to any one of claims 6 to 8 is used to control the dual fuel injection system control method according to any one of claims 1 to 5, wherein the dual fuel injection system control device (8) comprises: A determination module, used for determining whether the dual fuel injection system needs to be cleaned of carbon deposits; A first control module, configured to control the dual-fuel injection system to execute the carbon deposit removal mode when the dual-fuel injection system needs to remove carbon deposits; The second control module is used to control the dual fuel injection system to execute the normal working mode when the dual fuel injection system does not need to remove carbon deposits.

10. A vehicle, characterized in that It comprises the dual fuel injection system control device (8) as claimed in claim 9.

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