Engine control method and engine

Abstract

The application discloses an engine control method and an engine. The engine control method comprises the following steps: determining whether to adjust the set start scavenging crank angle and the set scavenging crank angle change amount of the next scavenging according to the exhaust gas residual amount in the precombustion chamber; and adjusting the set start scavenging crank angle and the set scavenging crank angle change amount of the next scavenging according to the set start scavenging crank angle of the present scavenging, the set scavenging crank angle change amount of the present scavenging, the set limit start scavenging crank angle range and the set limit scavenging crank angle change amount range. By adjusting the set start scavenging crank angle and the set scavenging crank angle change amount of the next scavenging, the precombustion chamber can be accurately and efficiently scavenged, the scavenging quality can be effectively improved, and the ignition efficiency and the ignition reliability of igniting the gas in the precombustion chamber can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine, in particular to an engine control method and an engine. BACKGROUND

[0002] Pre-chamber ignition is one of the main implementation ways of engine ignition, which ignites pilot gas in the pre-chamber by spark plug, and sprays the ignited high-temperature and high-pressure pilot gas into the main combustion chamber through the channel between the pre-chamber and the main combustion chamber to ignite the gas in the main combustion chamber. In this way, the combustion duration of the gas in the main combustion chamber can be significantly shortened, lean gas can be ignited, the combustion temperature can be reduced, the emission of NOx can be reduced, the combustion efficiency can be improved, and the gas consumption of the engine can be reduced, etc. Therefore, it is widely studied and applied. Specifically, the pre-chamber ignition includes active ignition and passive ignition. The active ignition refers to that the gas in the pre-chamber is sent from outside the engine by an independent pipeline and ignited by a spark plug. The passive ignition refers to that the gas in the pre-chamber is obtained by being pressed from the main combustion chamber by a piston and ignited by a spark plug.

[0003] For the active ignition, the prior art usually sweeps the pre-chamber at the end of the exhaust stage of the main combustion chamber and the intake stage of the main combustion chamber, and sprays the gas into the pre-chamber during the compression stage of the main combustion chamber. Although it can achieve the purpose of igniting the gas in the main combustion chamber, the sweep quality and sweep efficiency of the pre-chamber, and the ignition efficiency and ignition reliability of the gas in the pre-chamber need to be improved. SUMMARY

[0004] The present application aims to provide an engine control method and an engine to solve the above problems existing in the prior art active ignition.

[0005] To achieve this goal, the present application adopts the following technical solutions:

[0006] An engine control method, the engine comprising a pre-chamber structure, the pre-chamber structure comprising a pre-chamber body, the pre-chamber body being provided with a pre-chamber; the engine control method comprising:

[0007] determining whether to adjust the set start scavenging crank angle and the set scavenging crank angle change amount of the next scavenging according to the residual exhaust gas amount in the pre-chamber this time;

[0008] adjusting the set start scavenging crank angle and the set scavenging crank angle change amount of the next scavenging according to the set start scavenging crank angle of the present scavenging, the set scavenging crank angle change amount of the present scavenging, the set limit start scavenging crank angle range and the set limit scavenging crank angle change amount range.

[0009] As a preferred solution of the above engine control method, the step of determining whether to adjust the set start scavenging crank angle at the next scavenging and the set scavenging crank angle change amount at the next scavenging according to the remaining exhaust gas amount in the precombustion chamber this time includes:

[0010] determining whether the mass fraction of the remaining exhaust gas in the precombustion chamber this time is less than a set exhaust gas mass fraction;

[0011] if the mass fraction of the remaining exhaust gas in the precombustion chamber this time is less than the set exhaust gas mass fraction, keeping the set start scavenging crank angle at the next start scavenging equal to the set start scavenging crank angle at the this start scavenging, and keeping the set scavenging crank angle change amount at the next scavenging equal to the set scavenging crank angle change amount at the this scavenging;

[0012] if the mass fraction of the remaining exhaust gas in the precombustion chamber this time is greater than or equal to the set exhaust gas mass fraction, adjusting the set start scavenging crank angle at the next scavenging and the set scavenging crank angle change amount at the next scavenging.

[0013] As a preferred solution of the above engine control method, the step of adjusting the set start scavenging crank angle at the next scavenging and the set scavenging crank angle change amount at the next scavenging according to the set start scavenging crank angle at the this scavenging, the set scavenging crank angle change amount at the this scavenging, a set limit start scavenging crank angle range and a set limit scavenging crank angle change amount range includes:

[0014] determining whether (the set start scavenging crank angle at the this scavenging + M°CA) is less than or equal to the minimum value of the set limit start scavenging crank angle range; wherein 0 > M ≥ -5;

[0015] if (the set start scavenging crank angle at the this scavenging + M°CA) is greater than the minimum value of the set limit start scavenging crank angle range and less than or equal to the maximum value of the set limit start scavenging crank angle range, adjusting the set start scavenging crank angle at the next scavenging = the set start scavenging crank angle at the this scavenging + M°CA.

[0016] As a preferred solution of the above engine control method, if (the set start scavenging crank angle at the this scavenging + M°CA) is less than or equal to the minimum value of the set limit start scavenging crank angle range, determining whether (the set scavenging crank angle change amount at the this scavenging + N°CA) is greater than or equal to the maximum value of the set limit scavenging crank angle change amount range; wherein 0 < N ≤ 5;

[0017] If (the set scavenging crank angle change amount at this time of scavenging + N°CA) is greater than or equal to the minimum value of the set limit scavenging crank angle change amount range and less than the maximum value of the set limit scavenging crank angle change amount range, then the set scavenging crank angle change amount at the next time of scavenging is adjusted = the set scavenging crank angle change amount at this time of scavenging + N°CA.

[0018] As a preferred aspect of the above engine control method, the set limit start scavenging crank angle range is -360°CA ~ -300°CA.

[0019] The set limit scavenging crank angle change amount range is 40°CA ~ 80°CA.

[0020] As a preferred aspect of the above engine control method, the precombustion chamber body is provided with a main gas passage that communicates with the precombustion chamber, and an input end of the main gas passage selectively communicates with a gas source; the engine control method further comprises:

[0021] After the end of scavenging, when the crank angle rotates to the set start fueling crank angle, the main gas passage and the gas source are communicated, and the gas source is synchronously controlled to deliver gas to the main gas passage;

[0022] The main gas passage and the gas source are disconnected according to the set fueling crank angle change amount at this time of fueling gas;

[0023] The set fueling crank angle change amount at the next time of fueling gas is adjusted according to the mass fraction of the gas in the precombustion chamber at this time of ignition, the set fueling crank angle change amount at this time of fueling gas, and the set limit fueling crank angle change amount range.

[0024] As a preferred aspect of the above engine control method, the step of adjusting the set fueling crank angle change amount at the next time of fueling gas according to the mass fraction of the gas in the precombustion chamber at this time of ignition, the set fueling crank angle change amount at this time of fueling gas, and the set limit fueling crank angle change amount range comprises:

[0025] Judging whether the mass fraction of the gas in the precombustion chamber at this time of ignition is within a set gas mass fraction range;

[0026] If the mass fraction of the gas in the precombustion chamber at this time of ignition is within the set gas mass fraction range, then the set fueling crank angle change amount at the next time of fueling gas is kept equal to the set fueling crank angle change amount at this time of fueling gas;

[0027] If the mass fraction of the fuel gas in the pre-combustion chamber at the current ignition is less than the minimum value of the set fuel gas mass fraction range, it is determined whether (the set fuel gas injection crank angle change amount at the current fuel gas injection + L°CA) is within the set limit fuel gas injection crank angle change amount range; wherein 0

[0028] If (the set fuel gas injection crank angle change amount at the current fuel gas injection + L°CA) is within the set limit fuel gas injection crank angle change amount range, the set fuel gas injection crank angle change amount at the next fuel gas injection is adjusted to be equal to the set fuel gas injection crank angle change amount at the current fuel gas injection + L°CA.

[0029] If the mass fraction of the fuel gas in the pre-combustion chamber at the current ignition is greater than the maximum value of the set fuel gas mass fraction range, it is determined whether (the set fuel gas injection crank angle change amount at the current fuel gas injection - L°CA) is within the set limit fuel gas injection crank angle change amount range.

[0030] If (the set fuel gas injection crank angle change amount at the current fuel gas injection - L°CA) is within the set limit fuel gas injection crank angle change amount range, the set fuel gas injection crank angle change amount at the next fuel gas injection is adjusted to be equal to the set fuel gas injection crank angle change amount at the current fuel gas injection - L°CA.

[0031] As a preferred solution of the above engine control method, the set limit fuel gas injection crank angle change amount range is 40°CA-100°CA.

[0032] As a preferred solution of the above engine control method, the pre-combustion chamber body is further provided with a main scavenging passage in communication with the pre-combustion chamber, and an input end of the main scavenging passage is selectively in communication with a scavenging gas source.

[0033] Before determining whether to adjust the set start scavenging crank angle at the next scavenging and the set scavenging crank angle change amount at the next scavenging according to the residual exhaust gas amount in the pre-combustion chamber, the following steps are further included:

[0034] The input end of the main scavenging passage and the scavenging gas source are connected according to the set start scavenging crank angle at the current scavenging, and the scavenging gas source is synchronously controlled to deliver gas to the main scavenging passage for scavenging;

[0035] The input end of the main scavenging passage and the scavenging gas source are disconnected according to the set scavenging crank angle change amount at the current scavenging to end the scavenging.

[0036] An engine including a pre-chamber structure, the pre-chamber structure including a pre-chamber body provided with a pre-combustion chamber; and an engine control method as described above is executed.

[0037] The present application has the following advantages:

[0038] The application discloses an engine control method and an engine. The engine control method comprises: determining whether to adjust a set start scavenging crank angle and a set scavenging crank angle change amount of next scavenging according to a residual amount of exhaust gas in a precombustion chamber; and adjusting the set start scavenging crank angle and the set scavenging crank angle change amount of next scavenging according to a set start scavenging crank angle of this scavenging, a set scavenging crank angle change amount of this scavenging, a set limit start scavenging crank angle range and a set limit scavenging crank angle change amount range.

[0039] By adjusting the set start scavenging crank angle and the set scavenging crank angle change amount of next scavenging, the precombustion chamber can be accurately and efficiently scavenged, so that the scavenging quality can be effectively improved, the risk of gas leakage from the precombustion chamber to the main combustion chamber of the engine can be effectively reduced, and the ignition efficiency and ignition reliability of the gas in the precombustion chamber can be effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a structural schematic view of a precombustion chamber structure provided by an embodiment of the application;

[0041] Figure 2 is Figure 1 a sectional view along A-A;

[0042] Figure 3 is Figure 1 a sectional view along B-B Figure 1 ;

[0043] Figure 4 is Figure 1 a sectional view along B-B Figure 2 ;

[0044] Figure 5 is Figure 2 a sectional view along C-C;

[0045] Figure 6 is a flowchart of an engine control method provided by an embodiment of the application Figure 1 ;

[0046] Figure 7 is a flowchart of an engine control method provided by an embodiment of the application Figure 2 ;

[0047] Figure 8 is a flowchart of an engine control method provided by an embodiment of the application Figure 3 ;

[0048] Figure 9The flow chart of the engine control method provided by the embodiment of the present application Figure 4 ;

[0049] Figure 10 The flow chart of the engine control method provided by the embodiment of the present application Figure 5 ;

[0050] Figure 11 The curve chart of the excess air coefficient in the pre-combustion chamber and the crank angle provided by the embodiment of the present application

[0051] Figure 12 The curve chart of the mass fraction of the gas in the pre-combustion chamber and the crank angle provided by the embodiment of the present application

[0052] In the figure:

[0053] 1, pre-combustion chamber body; 11, pre-combustion chamber; 111, first sub-chamber; 112, second sub-chamber; 12, center mounting hole; 13, vent hole; 14, main scavenging passage; 141, sub-scavenging passage; 142, annular scavenging passage; 15, main gas passage; 151, sub-gas passage; 152, annular gas passage;

[0054] 2, control valve block;

[0055] 3, intake manifold;

[0056] 4, intake branch pipe. DETAILED DESCRIPTION

[0057] The present application will be further described below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0058] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood in a broad sense, for example, it can be fixedly connected, or detachably connected, or integrated; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0059] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0060] In the description of the present embodiment, the terms "upper", "lower", "right", "left", and other orientation or position relationships are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used to distinguish in description and have no special meaning.

[0061] The present application provides an engine, comprising a pre-chamber structure. As shown in the figure, the pre-chamber structure comprises a pre-chamber body 1, which is provided with a pre-combustion chamber 11. Fuel gas is introduced into the pre-combustion chamber 11, and by igniting the fuel gas in the pre-combustion chamber 11, the fuel gas in the main combustion chamber of the engine can be ignited to achieve active ignition. So that the engine can work normally and orderly. Figures 1-4

[0062] Specifically, as shown in the figure, the top of the pre-chamber body 1 is provided with a center mounting hole 12 communicating with the pre-combustion chamber 11, which is used to mount a spark plug. To achieve the ability to ignite the fuel gas in the pre-combustion chamber 11. Preferably, the center axis of the center mounting hole 12 is collinear with the center axis of the pre-combustion chamber 11. Figures 2-4

[0063] Specifically, as shown in the figure, the bottom of the pre-chamber body 1 is provided with an air hole 13 communicating with the pre-combustion chamber 11. The air hole 13 communicates with the main combustion chamber of the engine. When scavenging, the exhaust gas in the pre-combustion chamber 11 flows to the main combustion chamber through the air hole 13 and flows out of the main combustion chamber. When igniting, the ignited fuel gas in the pre-combustion chamber 11 is injected into the main combustion chamber through the air hole 13, which can ignite the fuel gas in the main combustion chamber to achieve active ignition. Figures 1-5

[0064] ​​​Preferably, there are multiple vent holes 13, spaced apart along the circumference of the pre-combustion chamber 11. This improves the uniformity of gas injection and enhances the efficiency and reliability of igniting the gas in the main combustion chamber. Furthermore, preferably, the multiple vent holes 13 are evenly spaced apart along the circumference of the pre-combustion chamber 11, further improving gas injection uniformity.

[0065] Among them, such as Figures 2-4 As shown, the pre-combustion chamber body 1 is further provided with an active scavenging channel 14 and an active fuel gas channel 15, both communicating with the pre-combustion chamber 11. Along the height of the pre-combustion chamber 11, the active fuel gas channel 15 is located below the active scavenging channel 14. The pre-combustion chamber structure also includes a control valve block 2, which selectively connects and disconnects the input of the active scavenging channel 14 from the scavenging gas source, and selectively connects and disconnects the input of the active fuel gas channel 15 from the fuel gas source.

[0066] When the pre-combustion chamber 11 is scavenged, the control valve block 2 controls the input end of the active scavenging channel 14 to be connected to the scavenging gas source, and the input end of the active gas channel 15 to be disconnected from the gas source. When gas is introduced into the pre-combustion chamber 11, the control valve block 2 controls the input end of the active scavenging channel 14 to be disconnected from the scavenging gas source, and the input end of the active gas channel 15 to be connected to the gas source. When the pre-combustion chamber 11 is not scavenged and gas is not introduced, the control valve block 2 controls the input end of the active scavenging channel 14 to be disconnected from the scavenging gas source, and the input end of the active gas channel 15 to be disconnected from the gas source. This arrangement makes the active scavenging of the pre-combustion chamber 11 and the active gas injection of the pre-combustion chamber 11 independent of each other and do not interfere with each other, making it convenient to adjust the start time of the active scavenging and the start time of the active gas injection. Secondly, along the height direction of the pre-combustion chamber 11, an active gas channel 15 is arranged below the active scavenging channel 14, so that the active scavenging channel 14 is close to the top of the pre-combustion chamber body 1 relative to the active gas channel 15, so that when gas is introduced into the pre-combustion chamber 11 through the active scavenging channel 14, the effect and efficiency of scavenging the pre-combustion chamber 11 can be effectively improved. In addition, when gas is introduced into the pre-combustion chamber 11 through the active gas channel 15, the introduced gas can also further purge the pre-combustion chamber 11, thereby further improving the effect and efficiency of scavenging the pre-combustion chamber 11, so as to effectively reduce the risk of gas in the pre-combustion chamber 11 leaking into the main combustion chamber of the engine.

[0067] Specifically, in the present embodiment, the control valve block 2 comprises two on-off valves. The two on-off valves comprise a first on-off valve and a second on-off valve. The input end of the first on-off valve is in communication with the scavenging gas source, and the output end of the first on-off valve is in communication with the input end of the main scavenging passage 14 through one of the intake branch pipes 4. The input end of the second on-off valve is in communication with the fuel gas source, and the output end of the second on-off valve is in communication with the input end of the main fuel gas passage 15 through the other intake branch pipe 4. As an alternative, the control valve block 2 can also be a solenoid reversing valve. It is sufficient to selectively connect and disconnect the input end of the main scavenging passage 14 with the scavenging gas source and to selectively connect and disconnect the input end of the main fuel gas passage 15 with the fuel gas source. For example, the solenoid reversing valve is a three-position four-way solenoid reversing valve.

[0068] Specifically, as shown in Figures 2-4 the main scavenging passage 14 comprises a sub-scavenging passage group, and the sub-scavenging passage group comprises a plurality of sub-scavenging passages 141 distributed along the circumference of the pre-combustion chamber 11. The angle between the direction of the gas flowing from the sub-scavenging passages 141 to the pre-combustion chamber 11 and the direction of the pre-combustion chamber 11 from top to bottom is a first angle, which is greater than 90° and less than 180°. In this way, the gas injected into the pre-combustion chamber 11 by each sub-scavenging passage 141 is inclined downward along the height direction of the pre-combustion chamber 11, which helps to discharge the exhaust gas generated in the last cycle in the pre-combustion chamber 11, so as to effectively improve the scavenging effect of the pre-combustion chamber 11, thereby effectively reducing the risk of fuel gas leakage from the pre-combustion chamber 11 into the main combustion chamber and improving the working performance of the pre-chamber structure.

[0069] Preferably, as shown in Figures 2-4As shown, the number of sub-scavenge channel groups is multiple, and the multiple sub-scavenge channel groups are distributed along the height direction of the pre-combustion chamber 11. Along the direction from top to bottom of the pre-combustion chamber 11, the first angles corresponding to the multiple sub-scavenge channel groups gradually increase. The number of sub-scavenge channel groups is set to be multiple, and the multiple sub-scavenge channel groups are distributed along the height direction of the pre-combustion chamber 11, so that the coverage area of the active scavenge channel 14 is large, and the scavenge effect and scavenge efficiency of the pre-combustion chamber 11 can be further improved, thereby further reducing the risk of gas leakage from the pre-combustion chamber 11 to the main combustion chamber, and further improving the working performance of the pre-combustion chamber structure. Secondly, along the direction from top to bottom of the pre-combustion chamber 11, the first angles corresponding to the multiple sub-scavenge channel groups gradually increase, so that the gas injected into the central region of the pre-combustion chamber 11 by the sub-scavenge channel groups is distributed in sequence along the height direction of the pre-combustion chamber 11 from top to bottom, thereby further improving the scavenge effect and scavenge efficiency of the pre-combustion chamber 11. The central region of the pre-combustion chamber 11 refers to the region where the central axis of the pre-combustion chamber 11 is located. It can be understood that the direction from top to bottom of the pre-combustion chamber 11, the direction from bottom to top of the pre-combustion chamber 11, the height direction of the pre-combustion chamber 11 and the central axis of the pre-combustion chamber 11 are all parallel.

[0070] Preferably, as shown in the drawings, Figures 2-4 As shown, the multiple sub-scavenge channel groups are uniformly distributed along the height direction of the pre-combustion chamber 11. The multiple sub-scavenge channels 141 in each sub-scavenge channel group are uniformly distributed along the circumferential direction of the pre-combustion chamber 11. In this embodiment, two sub-scavenge channel groups are set as an example, and each sub-scavenge channel group includes five sub-scavenge channels 141 uniformly distributed along the circumferential direction of the pre-combustion chamber 11.

[0071] Preferably, as shown in the drawings, Figures 2-4 As shown, the multiple sub-scavenge channels 141 in one of the two adjacent sub-scavenge channel groups along the height direction of the pre-combustion chamber 11 are staggered distributed along the circumferential direction of the pre-combustion chamber 11 with the multiple sub-scavenge channels 141 in the other sub-scavenge channel group. This can further increase the scavenge range of the active scavenge channel 14, thereby further improving the scavenge effect and scavenge efficiency of the pre-combustion chamber 11. As an alternative, the multiple sub-scavenge channels 141 in one of the two adjacent sub-scavenge channel groups along the height direction of the pre-combustion chamber 11 correspond one-to-one with the multiple sub-scavenge channels 141 in the other sub-scavenge channel group, and are arranged at the same position along the circumferential direction of the pre-combustion chamber 11.

[0072] Preferably, as shown in the drawings, Figures 2-4As shown, the sub-scavenging passages 141 are arc-shaped; along the height direction of the pre-combustion chamber 11, the opening of the arc-shaped sub-scavenging passages 141 faces downward. In this way, along the height direction of the pre-combustion chamber 11, the gas injected into the pre-combustion chamber 11 by each of the sub-scavenging passages 141 is inclined downward, so as to facilitate the discharge of the exhaust gas generated in the previous cycle in the pre-combustion chamber 11. As an alternative, the sub-scavenging passages 141 can also be linear, and the angle between the direction in which the gas flows into the pre-combustion chamber 11 from the linear sub-scavenging passages 141 and the direction of the pre-combustion chamber 11 from top to bottom is greater than or equal to 90° and less than 180°. Along the height direction of the pre-combustion chamber 11, the gas injected into the pre-combustion chamber 11 by each of the sub-scavenging passages 141 is also inclined downward, so as to facilitate the discharge of the exhaust gas generated in the previous cycle in the pre-combustion chamber 11.

[0073] Preferably, the aperture of the sub-scavenging passages 141 gradually decreases from the input end of the sub-scavenging passages 141 to the output end of the sub-scavenging passages 141. It can be understood that the cross-sectional area of the sub-scavenging passages 141 perpendicular to the extending direction of the sub-scavenging passages 141 gradually decreases from the input end of the sub-scavenging passages 141 to the output end of the sub-scavenging passages 141. In this way, the speed of the gas injected into the pre-combustion chamber 11 from the sub-scavenging passages 141 can be effectively increased, so as to further improve the scavenging effect and scavenging efficiency of the pre-combustion chamber 11. As an alternative, the apertures of the sub-scavenging passages 141 are equal everywhere along the sub-scavenging passages 141.

[0074] Specifically, as shown in FIG. 1, Figures 2-4 The main scavenging passage 14 further includes a ring-shaped scavenging passage 142 located in the pre-combustion chamber body 1, the ring-shaped scavenging passage 142 is in communication with each of the sub-scavenging passages 141 of each sub-scavenging passage group and one of the output ends of the control valve block 2. In this way, one end of each of the sub-scavenging passages 141 is in communication and can selectively communicate with the scavenging gas source.

[0075] Specifically, in the present embodiment, the gas supplied by the scavenging gas source is fuel gas, and the fuel gas is methane. The fuel gas supplied by the fuel gas source is also methane. As an alternative, the gas supplied by the scavenging gas source is air. In other embodiments, the fuel gas can also be replaced by hydrogen or other hydrocarbons.

[0076] Specifically, as shown in FIG. 1, Figures 2-4As shown, the active scavenging passage 14 comprises a sub-gas passage group, which comprises a plurality of sub-gas passages 151 distributed along the circumference of the pre-combustion chamber 11. One end of each sub-gas passage 151 is in communication with another output end of the control valve block 2, and the other end of each sub-gas passage 151 is in communication with the pre-combustion chamber 11. The angle between the direction of gas flow from the sub-gas passage 151 to the pre-combustion chamber 11 and the direction of the pre-combustion chamber 11 from top to bottom is a second angle, which is less than or equal to 90°. When the angle between the direction of gas flow from the sub-gas passage 151 to the pre-combustion chamber 11 and the direction of the pre-combustion chamber 11 from top to bottom is less than 90°, the gas injected into the pre-combustion chamber 11 by each sub-scavenging passage 141 is inclined upward along the height direction of the pre-combustion chamber 11, so that the gas can accumulate upward near the spark plug along the height direction of the pre-combustion chamber 11, thereby making the gas around the spark plug as dense as possible, and further discharging the exhaust gas generated in the last cycle in the pre-combustion chamber 11 by using the inclined upward injection of gas, which is beneficial to improve the ignition efficiency and ignition reliability of the gas in the pre-combustion chamber 11. When the angle between the direction of gas flow from the sub-gas passage 151 to the pre-combustion chamber 11 and the direction of the pre-combustion chamber 11 from top to bottom is equal to 90°, the gas injected in the horizontal direction can make the gas mixture in the pre-combustion chamber 11 more uniform, which is beneficial to the ignition of the current cycle gas.

[0077] Preferably, as shown in the drawings, Figures 2-4 The number of sub-gas passage groups is multiple, and the multiple sub-gas passage groups are distributed along the height direction of the pre-combustion chamber 11. Along the direction of the pre-combustion chamber 11 from top to bottom, the corresponding second angles of the multiple sub-gas passage groups gradually increase. By setting the number of sub-gas passage groups to be multiple and the multiple sub-gas passage groups to be distributed along the height direction of the pre-combustion chamber 11, the coverage area of the active gas passage 15 can be increased, thereby further improving the uniformity of the gas mixture in the pre-combustion chamber 11. Secondly, by setting the corresponding second angles of the multiple sub-gas passage groups to gradually increase along the direction of the pre-combustion chamber 11 from top to bottom, the gas injected into the central region of the pre-combustion chamber by the sub-gas passage group is distributed in sequence along the height direction of the pre-combustion chamber from top to bottom, thereby further improving the uniformity of the gas mixture in the pre-combustion chamber 11.

[0078] Preferably, as shown in the drawings, Figures 2-4 The multiple sub-gas passage groups are uniformly distributed along the height direction of the pre-combustion chamber 11. Each sub-gas passage 151 in each sub-gas passage group is uniformly distributed along the circumference of the pre-combustion chamber 11.

[0079] Preferably, the sub-gas passages 151 are linear, and the angle between the direction of gas flow from the linear sub-gas passages 151 to the pre-combustion chamber 11 and the direction of the pre-combustion chamber 11 from top to bottom is less than or equal to 90°. This enables the gas to be quickly and efficiently accumulated in the top central area of the pre-combustion chamber 11, thereby further facilitating the improvement of the ignition efficiency and ignition reliability of the ignition of the gas in the pre-combustion chamber 11.

[0080] Specifically, as shown in Figures 2-4 the main gas passage 15 further comprises an annular gas passage 152 located in the pre-combustion chamber body 1, the annular gas passage 152 is in communication with each sub-gas passage 151 of each sub-gas passage group and is in communication with another output end of the control valve block 2. To achieve that one end of each sub-gas passage 151 is in communication and can selectively communicate with the gas source.

[0081] Preferably, as shown in Figures 2-4 the pre-combustion chamber 11 comprises a first sub-chamber 111 in the shape of a cone and a second sub-chamber 112 in the shape of a cylinder; along the height direction of the pre-combustion chamber 11, the first sub-chamber 111 is located above the second sub-chamber 112, and the small end of the first sub-chamber 111 is in communication with the second sub-chamber 112. The angle between the direction of gas flow from the sub-gas passages 151 to the pre-combustion chamber 11 and the direction of the pre-combustion chamber 11 from top to bottom is less than 90° for the sub-gas passage groups located in the area of the first sub-chamber 111; the angle between the direction of gas flow from the sub-gas passages 151 to the pre-combustion chamber 11 and the direction of the pre-combustion chamber 11 from top to bottom is equal to 90° for the sub-gas passage groups located in the area of the second sub-chamber 112. In this way, the sub-gas passage groups located in the area of the first sub-chamber 111 can enable the gas to accumulate upward along the height direction of the pre-combustion chamber 11 near the spark plug, thereby making the gas around the spark plug as thick as possible, and the sub-gas passage groups located in the area of the second sub-chamber 112 can enable the gas in the pre-combustion chamber 11 to be mixed more uniformly, which is conducive to the ignition of the current cycle of gas. This can effectively improve the ignition efficiency of the ignition of the gas in the pre-combustion chamber 11 and effectively improve the mixing uniformity of the gas in the pre-combustion chamber 11.

[0082] Specifically, in the present embodiment, as shown in Figures 2-4 along the height direction of the pre-combustion chamber 11, the center mounting hole 12 and the plurality of sub-scavenging passages 141 of the main scavenging passage 14 are all located at the top of the first sub-chamber 111 and are in communication with the first sub-chamber 111. The vent hole 13 is located at the bottom of the second sub-chamber 112 and is in communication with the second sub-chamber 112.

[0083] In the present embodiment, as shown in Figures 1-4As shown, five sub-gas passage groups are set as an example, and the five sub-gas passage groups are evenly spaced along the height direction of the pre-combustion chamber 11. Two of the sub-gas passage groups are located in the region of the first sub-chamber 111, and the remaining three sub-gas passage groups are located in the region of the second sub-chamber 112. Specifically, the two sub-gas passage groups located in the region of the first sub-chamber 111 have an angle between the direction of gas flow from the sub-gas passage 151 to the pre-combustion chamber 11 and the downward direction of the pre-combustion chamber 11 less than 90°, and the corresponding angles of the two sub-gas passage groups gradually increase along the downward direction of the pre-combustion chamber 11. The three sub-gas passage groups located in the region of the second sub-chamber 112 have an angle between the direction of gas flow from the sub-gas passage 151 to the pre-combustion chamber 11 and the downward direction of the pre-combustion chamber 11 equal to 90°.

[0084] In the embodiment, each sub-gas passage group includes five sub-gas passages 151 as an example, and the five sub-gas passages 151 of each sub-gas passage group are evenly spaced along the circumference of the pre-combustion chamber 11.

[0085] Specifically, as shown, Figures 6-9 The pre-combustion chamber structure further includes an intake manifold 3, an input end of the intake manifold 3 is used to communicate with the scavenging gas source and the fuel gas source, and an output end of the intake manifold 3 communicates with the input end of the control valve block 2.

[0086] In the embodiment, the scavenging gas source and the fuel gas source are the same gas supply source. The input end of the intake manifold 3 communicates with the gas supply source. As an alternative, the intake manifold 3 is provided with two inlets, one of which communicates with the scavenging gas source and the other of which communicates with the fuel gas source.

[0087] Preferably, the sum of the end surface areas of the output ends of the sub-scavenging passages 141 is equal to the intake cross-sectional area of the intake manifold 3 perpendicular to the extension direction thereof. In order to avoid pressure loss caused by gas delivery.

[0088] Preferably, the sum of the end surface areas of the output ends of the sub-gas passages 151 is equal to the intake cross-sectional area of the intake manifold 3 perpendicular to the extension direction thereof. In order to avoid pressure loss caused by gas delivery.

[0089] The application also provides an engine control method for implementing the above-mentioned engine. By adopting the engine control method, the scavenging quality of the pre-combustion chamber 11 can be effectively improved, and the ignition efficiency and ignition reliability of the fuel gas in the pre-combustion chamber 11 can be effectively improved.

[0090] As shown, Figures 6-8 The engine control method includes:

[0091] S100, according to the set start scavenging crank angle of the current scavenging, the input end of the active scavenging passage 14 is connected with the scavenging gas source, and the scavenging gas source is synchronously controlled to deliver gas to the active scavenging passage 14 to perform scavenging.

[0092] Specifically, step S100 includes:

[0093] It is judged whether the current crank angle is the set start scavenging crank angle of the current scavenging.

[0094] If the current crank angle is the set start scavenging crank angle of the current scavenging, the input end of the active scavenging passage 14 is connected with the scavenging gas source. The scavenging gas source is synchronously controlled to deliver gas to the active scavenging passage 14 to perform scavenging. So that the time when the precombustion chamber 11 starts to perform scavenging can be accurately controlled.

[0095] The set start scavenging crank angle of the first scavenging is the optimal scavenging crank angle determined when the engine works last time. Or, the set start scavenging crank angle of the first scavenging is the experience value obtained by a large number of experiments in the early stage. The set start scavenging crank angle corresponds to the end of the intake stage or the exhaust stage of the engine. In this embodiment, the set start scavenging crank angle of the first scavenging is-320°CA as an example.

[0096] S200, according to the set scavenging crank angle change amount of the current scavenging, the input end of the active scavenging passage 14 is disconnected with the scavenging gas source to end the scavenging.

[0097] Specifically, step S200 includes:

[0098] It is judged whether the crank angle change amount after starting scavenging reaches the set scavenging crank angle change amount of the current scavenging. If the crank angle change amount after starting scavenging reaches the set scavenging crank angle change amount of the current scavenging, the input end of the active scavenging passage 14 is disconnected with the scavenging gas source to end the scavenging. Specifically, the control valve block 2 is controlled to disconnect the input end of the active scavenging passage 14 with the scavenging gas source at this time. So that the time when the precombustion chamber 11 ends the scavenging can be accurately controlled. In this embodiment, the set scavenging crank angle change amount of the first scavenging is 60°CA as an example.

[0099] It can be understood that in the process of executing steps S100 and S200, the input end of the active gas passage 15 and the gas source are always kept disconnected by the control valve block 2.

[0100] Specifically, during the execution of steps S100 and S200, the total amount of sweep gas injection is monitored synchronously. The total amount of sweep gas injection is kept less than or equal to 1% of the total amount of fuel gas. The total amount of fuel gas refers to the total amount of fuel gas introduced into the pre-chamber 11 and the main combustion chamber of the engine this time. Too much total amount of air injection is not conducive to the subsequent ignition of the fuel gas in the pre-chamber 11 when the sweep gas is air; too much total amount of fuel gas injection is not conducive to energy saving when the sweep gas is fuel gas. In the present embodiment, the sweep gas is exemplarily set to be fuel gas. Therefore, the total amount of sweep gas injection is monitored by a fuel gas mass sensor; or, the sweep gas concentration is monitored by a fuel gas concentration sensor, and the total amount of fuel gas injection is calculated according to the fuel gas concentration. The specific calculation method of calculating the total amount of fuel gas injection according to the fuel gas concentration belongs to the prior art, and will not be described here.

[0101] Specifically, while the input end of the active sweep gas passage 14 is disconnected from the sweep gas source, the remaining amount of exhaust gas in the pre-chamber 11 this time is monitored, and then step S300 is executed. Further, while the input end of the active sweep gas passage 14 is disconnected from the sweep gas source, step S500 is executed. It can be understood that whether the set start sweep gas crankshaft angle and the set sweep gas crankshaft angle change amount at the next sweep gas are adjusted or not, the series of actions after the sweep gas this time are normally performed.

[0102] Further, the remaining amount of exhaust gas is monitored by a mass sensor; or, the remaining exhaust gas concentration is monitored by a concentration sensor, and then the remaining amount of exhaust gas is calculated according to the remaining exhaust gas concentration. The specific calculation method of calculating the remaining amount of exhaust gas according to the remaining exhaust gas concentration belongs to the prior art, and will not be described here. Further, in the present embodiment, the exhaust gas mainly includes carbon dioxide. Therefore, the remaining amount of exhaust gas is monitored by a carbon dioxide mass sensor; or, the remaining carbon dioxide concentration is monitored by a carbon dioxide concentration sensor, and then the remaining amount of carbon dioxide is calculated according to the remaining carbon dioxide concentration.

[0103] S300, determining whether to adjust the set start sweep gas crankshaft angle and the set sweep gas crankshaft angle change amount at the next sweep gas according to the remaining amount of exhaust gas in the pre-chamber 11 this time.

[0104] Specifically, as shown in Figure 6 , step S300 includes:

[0105] S310, calculating the mass fraction of the remaining exhaust gas in the pre-chamber 11 this time according to the remaining amount of exhaust gas in the pre-chamber 11 this time. The specific calculation method of calculating the mass fraction of the remaining exhaust gas in the pre-chamber 11 this time according to the remaining amount of exhaust gas in the pre-chamber 11 this time belongs to the prior art, and will not be described here.

[0106] S320, determine whether the mass fraction of the remaining exhaust gas in the precombustion chamber 11 is less than the set exhaust gas mass fraction.

[0107] If the mass fraction of the remaining exhaust gas in the precombustion chamber 11 is less than the set exhaust gas mass fraction, step S330 is performed.

[0108] S330, keep the set start scavenging crank angle at the next start scavenging equal to the set start scavenging crank angle at the present start scavenging, and keep the set scavenging crank angle change amount at the next scavenging equal to the set scavenging crank angle change amount at the present scavenging.

[0109] If the mass fraction of the remaining exhaust gas in the precombustion chamber 11 is greater than or equal to the set exhaust gas mass fraction, step S340 is performed.

[0110] S340, adjust the set start scavenging crank angle at the next scavenging and the set scavenging crank angle change amount at the next scavenging.

[0111] The set exhaust gas mass fraction is an empirical value obtained from a large number of experiments in the early stage.

[0112] Specifically, if the mass fraction of the remaining exhaust gas in the precombustion chamber 11 is less than the set exhaust gas mass fraction, it indicates that the amount of residual exhaust gas in the precombustion chamber 11 is small at the end of scavenging, and the set start scavenging crank angle at the next start scavenging and the set scavenging crank angle change amount at the next scavenging can accurately and efficiently clean the exhaust gas in the precombustion chamber 11, so there is no need to adjust the set start scavenging crank angle at the next start scavenging and the set scavenging crank angle change amount at the next scavenging.

[0113] Specifically, if the mass fraction of the remaining exhaust gas in the precombustion chamber 11 is greater than or equal to the set exhaust gas mass fraction, it indicates that there is still a large amount of exhaust gas remaining in the precombustion chamber 11 at the end of scavenging, so the set start scavenging crank angle at the next start scavenging and the set scavenging crank angle change amount at the next scavenging need to be adjusted to enable subsequent accurate and efficient scavenging of the precombustion chamber 11, thereby effectively improving the scavenging quality. It can be understood that when the scavenging quality is improved, the amount of residual exhaust gas in the precombustion chamber 11 is small, thereby effectively reducing the risk of gas leakage from the precombustion chamber 11 to the main combustion chamber of the engine, thereby effectively improving the ignition efficiency and ignition reliability of the gas in the precombustion chamber 11.

[0114] Specifically, in this embodiment, the set exhaust gas mass fraction is 0.04. The set exhaust gas mass fraction is an empirical value obtained from a large number of experiments in the early stage.

[0115] S400, adjust the set start scavenging crank angle at the next scavenging and the set scavenging crank angle change amount at the next scavenging according to the set start scavenging crank angle at this scavenging, the set scavenging crank angle change amount at this scavenging, the set limit start scavenging crank angle range, and the set limit scavenging crank angle change amount range.

[0116] Specifically, as shown in Figure 7 , Figure 9 and Figure 10 , step S400 includes:

[0117] S410, determine whether (the set start scavenging crank angle at this scavenging + M°CA) is less than or equal to the minimum value of the set limit start scavenging crank angle range. Wherein, 0 > M ≥ -5.

[0118] If (the set start scavenging crank angle at this scavenging + M°CA) is greater than the minimum value of the set limit start scavenging crank angle range and less than or equal to the maximum value of the set limit start scavenging crank angle range, then execute step S420.

[0119] S420, adjust the set start scavenging crank angle at the next scavenging = the set start scavenging crank angle at this scavenging + M°CA.

[0120] If (the set start scavenging crank angle at this scavenging + M°CA) is less than or equal to the minimum value of the set limit start scavenging crank angle range, then execute step S430.

[0121] S430, determine whether (the set scavenging crank angle change amount at this scavenging + N°CA) is greater than or equal to the maximum value of the set limit scavenging crank angle change amount range. Wherein, 0 < N ≤ 5.

[0122] If (the set scavenging crank angle change amount at this scavenging + N°CA) is greater than or equal to the minimum value of the set limit scavenging crank angle change amount range and less than the maximum value of the set limit scavenging crank angle change amount range, then execute step S440.

[0123] S440, adjust the set scavenging crank angle change amount at the next scavenging = the set scavenging crank angle change amount at this scavenging + N°CA.

[0124] Specifically, when the mass fraction of the remaining exhaust gas amount in the pre-combustion chamber 11 is greater than or equal to the set exhaust gas mass fraction, if (the set start scavenging crank angle at this time of scavenging + M°CA) is greater than the minimum value of the set limit start scavenging crank angle range and less than or equal to the maximum value of the set limit start scavenging crank angle range, the set start scavenging crank angle at the next time of scavenging is adjusted to be smaller, so that the start time corresponding to the set start scavenging crank angle at the next time of scavenging is adjusted to be earlier, so that the pre-combustion chamber 11 can be accurately and efficiently scavenged in the future, so as to effectively improve the scavenging quality.

[0125] Specifically, when the mass fraction of the remaining exhaust gas amount in the pre-combustion chamber 11 is greater than or equal to the set exhaust gas mass fraction, if (the set start scavenging crank angle at this time of scavenging + M°CA) is less than or equal to the minimum value of the set limit start scavenging crank angle range, and (the set scavenging crank angle change amount at this time of scavenging + N°CA) is greater than or equal to the minimum value of the set limit scavenging crank angle change amount range and less than the maximum value of the set limit scavenging crank angle change amount range, the set scavenging crank angle change amount at the next time of scavenging is adjusted to be larger, so that the duration at the next time of scavenging is adjusted to be longer, so that the pre-combustion chamber 11 can be accurately and efficiently scavenged in the future, so as to effectively improve the scavenging quality.

[0126] Specifically, when the mass fraction of the remaining exhaust gas amount in the pre-combustion chamber 11 is greater than or equal to the set exhaust gas mass fraction, if (the set start scavenging crank angle at this time of scavenging + M°CA) is equal to the minimum value of the set limit start scavenging crank angle range, and (the set scavenging crank angle change amount at this time of scavenging + N°CA) is equal to the maximum value of the set limit scavenging crank angle change amount range, it indicates that there is a fault in the pre-combustion chamber structure and / or the control valve block 2 and / or the intake branch pipe 4 and / or other structures related to the pre-combustion chamber structure, etc., which needs to be repaired. Preferably, when the mass fraction of the remaining exhaust gas amount in the pre-combustion chamber 11 is greater than or equal to the set exhaust gas mass fraction, if (the set start scavenging crank angle at this time of scavenging + M°CA) is equal to the minimum value of the set limit start scavenging crank angle range, and (the set scavenging crank angle change amount at this time of scavenging + N°CA) is equal to the maximum value of the set limit scavenging crank angle change amount range, an alarm is issued. In order to facilitate the knowledge of the fault.

[0127] Therefore, by adjusting the set start scavenging crank angle at the next time of scavenging and the set scavenging crank angle change amount at the next time of scavenging, the pre-combustion chamber 11 can be accurately and efficiently scavenged in the future, so as to effectively improve the scavenging quality, thereby effectively reducing the risk of gas leaking from the pre-combustion chamber 11 into the main combustion chamber of the engine, and effectively improving the ignition efficiency and ignition reliability of the gas in the pre-combustion chamber 11.

[0128] Specifically, the limit start scavenging crank angle range is set as -360°CA~ -300°CA. The limit scavenging crank angle change range is set as 40°CA~ 80°CA. The limit start scavenging crank angle range is an experience range obtained from a large number of previous tests. The limit scavenging crank angle change range is an experience range obtained from a large number of previous tests.

[0129] Specifically, in the present embodiment, the values of M and N are both taken as 5 as an example.

[0130] S500, when the crank angle rotates to the set start fueling crank angle, the main active gas passage 15 and the gas source are connected, and the gas source is controlled to deliver gas to the main active gas passage 15 synchronously.

[0131] Specifically, step S500 includes:

[0132] It is judged whether the current crank angle is the set start fueling crank angle at this time of fueling.

[0133] If the current crank angle is the set start fueling crank angle at this time of fueling, the main active gas passage 15 and the gas source are connected. The gas source is controlled to deliver gas to the main active gas passage 15 synchronously.

[0134] So that the time when the precombustion chamber 11 starts fueling can be controlled accurately.

[0135] In the present embodiment, fueling starts when scavenging ends.

[0136] In other embodiments, fueling can also be started when the crank angle change reaches the set crank angle change after scavenging ends. The value range of the set crank angle change is 0°CA~ 30°CA. That is, the start time of fueling is delayed.

[0137] S600, the main active gas passage 15 and the gas source are disconnected according to the set fueling crank angle change at this time of fueling.

[0138] Specifically, step S600 includes:

[0139] It is judged whether the crank angle change after fueling starts reaches the set fueling crank angle change at this time of fueling. If the crank angle change after fueling starts reaches the set fueling crank angle change at this time of fueling, the main active gas passage 15 and the gas source are disconnected. Specifically, the control valve block 2 is controlled to disconnect the input end of the main active gas passage 15 and the gas source at this time. So that the time when the gas is disconnected can be controlled accurately. In the present embodiment, the set fueling crank angle change at the first time of fueling is taken as 60°CA as an example.

[0140] It can be understood that, in the process of executing steps S500 and S600, the input end of the active scavenging passage 14 and the scavenging gas source are always kept disconnected by controlling the valve block 2.

[0141] Specifically, while the active fuel gas passage 15 is disconnected from the fuel gas source, the amount of fuel gas in the pre-chamber 11 at the end of the current fuel gas admission is monitored, and then step S700 is executed. Secondly, while the input end of the active scavenging passage 14 is disconnected from the scavenging gas source, a series of actions such as subsequent ignition are executed. It can be understood that, regardless of the adjustment of the set fuel admission crank angle change amount for the next fuel gas admission, the series of actions after the end of the current fuel gas admission are normally performed.

[0142] Further, the amount of fuel gas is monitored by a fuel gas mass sensor; or the concentration of fuel gas is monitored by a fuel gas concentration sensor, and then the amount of fuel gas is calculated based on the concentration of fuel gas. The specific calculation method of calculating the amount of fuel gas based on the concentration of fuel gas belongs to the prior art, and will not be described here.

[0143] In this embodiment, since the scavenging gas and the fuel gas admitted during fuel gas admission are the same gas, the fuel gas mass sensor can be shared. This simplifies the structure and reduces the cost.

[0144] S700, adjusting the set fuel admission crank angle change amount for the next fuel gas admission based on the mass fraction of fuel gas in the pre-chamber 11 at the time of the current ignition, the set fuel admission crank angle change amount for the current fuel gas admission, and the set limit fuel admission crank angle change amount range. The specific calculation method of calculating the mass fraction of fuel gas based on the amount of fuel gas belongs to the prior art, and will not be described here.

[0145] Specifically, as shown in Figure 11 S700 includes:

[0146] S710, determining whether the mass fraction of fuel gas in the pre-chamber 11 at the time of the current ignition is within the set fuel gas mass fraction range.

[0147] If the mass fraction of fuel gas in the pre-chamber 11 at the time of the current ignition is within the set fuel gas mass fraction range, step S720 is executed.

[0148] S720, keeping the set fuel admission crank angle change amount for the next fuel gas admission equal to the set fuel admission crank angle change amount for the current fuel gas admission.

[0149] If the mass fraction of fuel gas in the pre-chamber 11 at the time of the current ignition is less than the minimum value of the set fuel gas mass fraction range, steps S731 and S732 are executed.

[0150] S731, determine whether (the set ignition crank angle change amount at this time of gas injection + L°CA) is within the set limit ignition crank angle change amount range. Wherein, 0 < L ≤ 5.

[0151] If (the set ignition crank angle change amount at this time of gas injection + L°CA) is within the set limit ignition crank angle change amount range, then execute step S732.

[0152] S732, adjust the set ignition crank angle change amount at next time of gas injection = the set ignition crank angle change amount at this time of gas injection + L°CA.

[0153] If the mass fraction of gas in the pre-combustion chamber 11 at this time of ignition is greater than the maximum value of the set gas mass fraction range, then execute step S741 and step 742.

[0154] S741, determine whether (the set ignition crank angle change amount at this time of gas injection - L°CA) is within the set limit ignition crank angle change amount range. Wherein, 0 < L ≤ 5.

[0155] If (the set ignition crank angle change amount at this time of gas injection - L°CA) is within the set limit ignition crank angle change amount range, then execute step S742.

[0156] S742, adjust the set ignition crank angle change amount at next time of gas injection = the set ignition crank angle change amount at this time of gas injection - L°CA.

[0157] Specifically, if the mass fraction of gas in the pre-combustion chamber 11 at this time of ignition is within the set gas mass fraction range, it indicates that the amount of gas in the pre-combustion chamber 11 at this time is appropriate, and the set ignition crank angle change amount at this time of gas injection is appropriate.

[0158] Specifically, if the mass fraction of gas in the pre-combustion chamber 11 at this time of ignition is less than the minimum value of the set gas mass fraction range, it indicates that the amount of gas in the pre-combustion chamber 11 is less, and by increasing the set ignition crank angle change amount at next time of gas injection, the duration of injecting gas at next time is increased, so that the pre-combustion chamber 11 can be accurately and efficiently filled with gas in the subsequent, thereby further improving the ignition efficiency and ignition reliability of igniting the gas in the pre-combustion chamber 11.

[0159] Specifically, if the mass fraction of gas in the pre-combustion chamber 11 at this time of ignition is greater than the maximum value of the set gas mass fraction range, it indicates that the amount of gas in the pre-combustion chamber 11 is too much, and by reducing the set ignition crank angle change amount at next time of gas injection, the duration of injecting gas at next time is reduced, so that the pre-combustion chamber 11 can also be accurately and efficiently filled with gas in the subsequent, thereby also further improving the ignition efficiency and ignition reliability of igniting the gas in the pre-combustion chamber 11.

[0160] Specifically, when the mass fraction of the fuel gas in the pre-combustion chamber 11 at the present ignition is less than the minimum value of the set fuel gas mass fraction range, if (the set fuel gas intake crank angle change amount at the present fuel gas intake + L°CA) is greater than the maximum value of the set limit fuel gas intake crank angle change amount range, it indicates that the pre-combustion chamber structure and / or the control valve block 2 and / or the intake branch pipe 4 and / or other structures related to the pre-combustion chamber structure and the like have a fault and need to be overhauled. Preferably, when the mass fraction of the fuel gas in the pre-combustion chamber 11 at the present ignition is less than the minimum value of the set fuel gas mass fraction range, if (the set fuel gas intake crank angle change amount at the present fuel gas intake + L°CA) is greater than the maximum value of the set limit fuel gas intake crank angle change amount range, an alarm is issued. In this way, the fault can be easily known.

[0161] Specifically, when the mass fraction of the fuel gas in the pre-combustion chamber 11 at the present ignition is greater than the maximum value of the set fuel gas mass fraction range, if (the set fuel gas intake crank angle change amount at the present fuel gas intake - L°CA) is less than the minimum value of the set limit fuel gas intake crank angle change amount range, it indicates that the pre-combustion chamber structure and / or the control valve block 2 and / or the intake branch pipe 4 and / or other structures related to the pre-combustion chamber structure and the like have a fault and need to be overhauled. Preferably, when the mass fraction of the fuel gas in the pre-combustion chamber 11 at the present ignition is greater than the maximum value of the set fuel gas mass fraction range, if (the set fuel gas intake crank angle change amount at the present fuel gas intake - L°CA) is less than the minimum value of the set limit fuel gas intake crank angle change amount range, an alarm is issued. In this way, the fault can be easily known.

[0162] Thus, by adjusting the set fuel gas intake crank angle change amount at the next fuel gas intake, the fuel gas can be accurately and efficiently introduced into the pre-combustion chamber 11 in the subsequent, so as to further improve the ignition efficiency and ignition reliability of igniting the fuel gas in the pre-combustion chamber 11.

[0163] Specifically, the set fuel gas mass fraction range is 0.049-0.053. The set fuel gas mass fraction range is an empirical range obtained from a large number of previous tests.

[0164] Specifically, the set limit fuel gas intake crank angle change amount range is 40°CA-100°CA. In the present embodiment, the set limit fuel gas intake crank angle change amount at the first fuel gas intake is set to be 60°CA. The set limit fuel gas intake crank angle change amount range is an empirical range obtained from a large number of previous tests.

[0165] Specifically, in the present embodiment, the value of L is taken as an example of 5.

[0166] Specifically, in the embodiment, the injection pressure of the scavenging gas and the injection pressure of the fuel gas into the pre-combustion chamber 11 are both 6 bar to 8 bar.

[0167] Specifically, in the embodiment, the set start scavenging crank angle is -320°CA at the first time of scavenging; the set scavenging crank angle change amount is 60°CA at the first time of scavenging; the fuel gas is injected when the scavenging is finished; the set fuel injection crank angle change amount is 60°CA at the first time of fuel injection.

[0168] The optimal control strategy obtained by the engine control method is as follows:

[0169] The set start scavenging crank angle is -345°CA at the time of scavenging; the set scavenging crank angle change amount is 65°CA. The set start fuel injection crank angle is -280°CA (i.e. the fuel injection is started when the scavenging is finished) at the time of fuel gas injection into the pre-combustion chamber 11; the set fuel injection crank angle change amount is 50°CA. Compared with the prior art, the mass fraction of the residual exhaust gas in the pre-combustion chamber 11 is reduced by 0.005. In order to form the equivalent combustion in the pre-combustion chamber 11, the equivalence ratio in the pre-combustion chamber 11 at the time of ignition should be near 1 or the excess air coefficient should be near 1, so that Figure 12 and ​ It can be seen that the mass fraction of the fuel gas in the pre-combustion chamber 11 at this time is 0.051, and the crank angle at the time of ignition is -15°CA.

[0170] Therefore, by using the engine control method, the scavenging quality of the pre-combustion chamber 11 can be effectively improved, and the ignition efficiency and the ignition reliability of the fuel gas in the pre-combustion chamber 11 can be effectively improved.

[0171] Obviously, the above-mentioned embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation modes of the present application. For those skilled in the art, various obvious changes, re-adjustments and replacements can be made without departing from the protection scope of the present application. Here, it is unnecessary and impossible to enumerate all the implementation modes. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the claims of the present application.

Claims

1. Method of engine control, the engine comprising a pre-chamber structure, said pre-chamber structure comprising a pre-chamber body (1) provided with a pre-combustion chamber (11); characterized in that, The pre-chamber body (1) is further provided with a main scavenging passage (14) in communication with the pre-chamber (11), an input end of the main scavenging passage (14) being selectively in communication with a scavenging gas source; the engine control method comprises: communicating the input end of the main scavenging passage (14) and the scavenging gas source according to a set start scavenging crank angle of the present scavenging, and synchronously controlling the scavenging gas source to deliver gas to the main scavenging passage (14) for scavenging; disconnecting the input end of the main scavenging passage (14) and the scavenging gas source according to a set scavenging crank angle change amount of the present scavenging to end the scavenging; determining whether to adjust a set start scavenging crank angle of the next scavenging and a set scavenging crank angle change amount of the next scavenging according to a residual exhaust gas amount in the pre-chamber (11) of the present scavenging; adjusting the set start scavenging crank angle of the next scavenging and the set scavenging crank angle change amount of the next scavenging according to the set start scavenging crank angle of the present scavenging, the set scavenging crank angle change amount of the present scavenging, a set limit start scavenging crank angle range and a set limit scavenging crank angle change amount range.

2. The engine control method according to claim 1, characterized by, The step of determining whether to adjust the set start scavenging crank angle of the next scavenging and the set scavenging crank angle change amount of the next scavenging according to the residual exhaust gas amount in the pre-chamber (11) of the present scavenging comprises: judging whether a mass fraction of residual exhaust gas in the pre-chamber (11) of the present scavenging is less than a set exhaust gas mass fraction; if the mass fraction of residual exhaust gas in the pre-chamber (11) of the present scavenging is less than the set exhaust gas mass fraction, keeping the set start scavenging crank angle of the next scavenging equal to the set start scavenging crank angle of the present scavenging, and keeping the set scavenging crank angle change amount of the next scavenging equal to the set scavenging crank angle change amount of the present scavenging; if the mass fraction of residual exhaust gas in the pre-chamber (11) of the present scavenging is greater than or equal to the set exhaust gas mass fraction, adjusting the set start scavenging crank angle of the next scavenging and the set scavenging crank angle change amount of the next scavenging.

3. The engine control method according to claim 1, characterized by, The step of adjusting the set start scavenging crank angle of the next scavenging and the set scavenging crank angle change amount of the next scavenging according to the set start scavenging crank angle of the present scavenging, the set scavenging crank angle change amount of the present scavenging, the set limit start scavenging crank angle range and the set limit scavenging crank angle change amount range comprises: judging whether (the set start scavenging crank angle of the present scavenging + M°CA) is less than or equal to a minimum value of the set limit start scavenging crank angle range; wherein 0 > M ≥ -5; if (the set start scavenging crank angle of the present scavenging + M°CA) is greater than the minimum value of the set limit start scavenging crank angle range and less than or equal to a maximum value of the set limit start scavenging crank angle range, adjusting the set start scavenging crank angle of the next scavenging = the set start scavenging crank angle of the present scavenging + M°CA.

4. The engine control method according to claim 3, characterized in that: If (the set start scavenging crank angle of this time + M°CA) is less than or equal to the minimum value of the set limit start scavenging crank angle range, it is determined whether (the set scavenging crank angle change amount of this time + N°CA) is greater than or equal to the maximum value of the set limit scavenging crank angle change amount range; wherein 0 If (the set scavenging crank angle change amount of this time + N°CA) is greater than or equal to the minimum value of the set limit scavenging crank angle change amount range and less than the maximum value of the set limit scavenging crank angle change amount range, the set scavenging crank angle change amount of the next time is adjusted = the set scavenging crank angle change amount of this time + N°CA.

5. The engine control method of any one of claims 1-4, characterized in that: The set limit start scavenging crank angle range is -360°CA~ -300°CA; The set limit scavenging crank angle change amount range is 40°CA~ 80°CA.

6. The engine control method according to any one of claims 1 to 4, characterized by, The precombustion chamber body (1) is provided with a main gas passage (15) in communication with the precombustion chamber (11), and the input end of the main gas passage (15) can selectively communicate with a gas source; the engine control method further comprises: After the end of scavenging, when the crank angle rotates to the set start fueling crank angle, the main gas passage (15) and the gas source are communicated, and the gas source is synchronously controlled to deliver gas to the main gas passage (15); According to the set fueling crank angle change amount of this time, the main gas passage (15) and the gas source are disconnected; According to the mass fraction of the gas in the precombustion chamber (11) at this time, the set fueling crank angle change amount of this time, and the set limit fueling crank angle change amount range, the set fueling crank angle change amount of the next time is adjusted.

7. The engine control method according to claim 6, characterized by, The step of adjusting the set fueling crank angle change amount of the next time according to the mass fraction of the gas in the precombustion chamber (11) at this time, the set fueling crank angle change amount of this time, and the set limit fueling crank angle change amount range comprises: It is determined whether the mass fraction of the gas in the precombustion chamber (11) at this time is within the set gas mass fraction range; If the mass fraction of the gas in the precombustion chamber (11) at this time is within the set gas mass fraction range, the set fueling crank angle change amount of the next time is kept equal to the set fueling crank angle change amount of this time; If the mass fraction of the gas in the precombustion chamber (11) at this time is less than the minimum value of the set gas mass fraction range, it is determined whether (the set fueling crank angle change amount of this time + L°CA) is within the set limit fueling crank angle change amount range; wherein 0 If (the set fueling crank angle change amount of this time + L°CA) is within the set limit fueling crank angle change amount range, the set fueling crank angle change amount of the next time is adjusted = the set fueling crank angle change amount of this time + L°CA; If the mass fraction of the fuel gas in the pre-combustion chamber (11) at the present ignition is greater than the maximum value of the set fuel gas mass fraction range, it is determined whether the set fuel gas intake crank angle change amount at the present fuel gas intake - L°CA is within the set limit fuel gas intake crank angle change amount range; If the set fuel gas intake crank angle change amount at the present fuel gas intake - L°CA is within the set limit fuel gas intake crank angle change amount range, the set fuel gas intake crank angle change amount at the next fuel gas intake is adjusted to be equal to the set fuel gas intake crank angle change amount at the present fuel gas intake - L°CA.

8. The engine control method according to claim 7, characterized in that: The set limit fuel gas intake crank angle change amount range is 40°CA to 100°CA.

9. Engine comprising a pre-chamber structure, said pre-chamber structure comprising a pre-chamber body (1) provided with a pre-combustion chamber (11); characterized in that, The pre-combustion chamber body (1) is further provided with a main scavenging passage (14) in communication with the pre-combustion chamber (11), an input end of the main scavenging passage (14) being selectively in communication with a scavenging gas source, and the engine being used to execute the engine control method according to any one of claims 1 to 8.

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