Engine control methods and engines

Abstract

This invention belongs to the field of engine technology and discloses an engine control method and an engine. The engine control method includes: determining the limiting crankshaft angle range corresponding to the start of scavenging in the pre-combustion chamber based on a preset injection pressure and a preset injection quantity; determining the conditions for starting scavenging in the pre-combustion chamber based on the temperature and pressure of the main combustion chamber, the preset injection pressure, and the limiting crankshaft angle range; and initiating scavenging in the pre-combustion chamber with the preset injection pressure and preset injection quantity. By employing this engine control method, the scavenging quality and efficiency of scavenging in the pre-combustion chamber can be effectively improved, as can the ignition efficiency and ignition reliability of igniting the combustion gases within the pre-combustion chamber.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and more particularly to engine control methods and engines. Background Technology

[0002] Pre-combustion chamber ignition is one of the main methods of engine ignition. It involves using a spark plug to ignite pilot gas in the pre-combustion chamber, and then injecting the ignited, high-temperature, high-pressure pilot gas into the main combustion chamber through a channel between the pre-combustion chamber and the main combustion chamber, igniting the gas inside the main combustion chamber. This significantly shortens the combustion duration of the gas in the main combustion chamber, ignites lean gases, lowers combustion temperature, reduces NOx emissions, improves combustion efficiency, and reduces engine fuel consumption, thus it is widely researched and applied. Specifically, pre-combustion chamber ignition includes active ignition and passive ignition. Active ignition refers to the gas in the pre-combustion chamber being introduced from outside the engine through a separate pipe and ignited by a spark plug; passive ignition refers to the gas in the pre-combustion chamber being forced into the main combustion chamber by the piston and ignited by a spark plug.

[0003] For active ignition, existing technologies typically involve scavenging the pre-combustion chamber at the end of the exhaust phase and during the intake phase of the main combustion chamber, and injecting gas into the pre-combustion chamber during the compression phase of the main combustion chamber. Although this can ignite the gas in the main combustion chamber, the scavenging quality and efficiency of the pre-combustion chamber, as well as the ignition efficiency and reliability of the gas in the pre-combustion chamber, all need to be improved. Summary of the Invention

[0004] The purpose of this invention is to provide an engine control method and an engine to solve the aforementioned problems of active ignition in the prior art.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] Engine control methods, including:

[0007] The limit crankshaft angle range at which scavenging begins when the pre-combustion chamber begins to be scavenged is determined based on the preset injection pressure and preset injection quantity.

[0008] The conditions for starting scavenging in the pre-combustion chamber are determined based on the temperature and pressure of the main combustion chamber, the preset injection pressure, and the crankshaft angle range at which scavenging begins.

[0009] The pre-combustion chamber is scavenged using the preset injection pressure and the preset injection quantity.

[0010] As a preferred embodiment of the above-mentioned engine control method, the step of determining the limit crankshaft angle range corresponding to the start of scavenging in the pre-combustion chamber based on the preset injection pressure and preset injection quantity includes:

[0011] The crankshaft angle range at the limit start of scavenging is obtained from the table based on the preset injection pressure and the preset injection quantity; wherein the table is formed by the preset injection pressure, the preset injection quantity and the crankshaft angle range at the limit start of scavenging.

[0012] As a preferred embodiment of the above engine control method, the step of determining the pre-combustion chamber scavenging condition based on the main combustion chamber temperature, the main combustion chamber pressure, the preset injection pressure, and the limit start-scavenging crankshaft angle range includes:

[0013] Determine if the crankshaft angle is within the range of the limit start scavenging crankshaft angle; determine if the temperature of the main combustion chamber is less than or equal to the set temperature; determine if the pressure difference is greater than or equal to the set scavenging pressure difference; the pressure difference = preset injection pressure - pressure of the main combustion chamber;

[0014] If the crankshaft angle is within the range of the limit start scavenging crankshaft angle, the temperature of the main combustion chamber is less than or equal to the set temperature, and the pressure difference is greater than or equal to the set scavenging pressure difference, then the pre-combustion chamber start scavenging condition is determined to be met.

[0015] As a preferred embodiment of the above engine control method, the set temperature range is 600K to 800K;

[0016] The range of the set scavenging pressure difference is 4 bar to 7 bar.

[0017] As a preferred embodiment of the above engine control method, the preset injection pressure ranges from 7 bar to 10 bar.

[0018] The preset injection quantity ranges from (0.5% * total gas volume) to (1% * total gas volume).

[0019] The total gas volume is the total amount of gas injected into the pre-combustion chamber and the main combustion chamber in each working cycle of the engine; the volume of the pre-combustion chamber accounts for 1% to 1.5% of the volume of the main combustion chamber.

[0020] As a preferred embodiment of the above engine control method, the preset injection pressure is 8 bar, the preset injection quantity is (1% * total gas quantity), and the crankshaft angle range for the limit start of scavenging is -345°CA to -180°CA.

[0021] As a preferred embodiment of the above engine control method, after scavenging the pre-combustion chamber with the preset injection pressure and the preset injection quantity, the method further includes the following steps:

[0022] Determine whether the pressure difference is less than the set intake and combustion pressure difference; the pressure difference = preset injection pressure - pressure of the main combustion chamber; if the pressure difference is less than the set intake and combustion pressure difference, then start injecting fuel into the pre-combustion chamber with the preset injection pressure and the preset injection quantity.

[0023] As a preferred embodiment of the above engine control method, the range of the set intake-fuel pressure differential is (1 bar, 4 bar).

[0024] An engine, the engine including a pre-combustion chamber structure, the pre-combustion chamber structure including a pre-combustion chamber body, the pre-combustion chamber body having a pre-combustion chamber and an intake passage communicating with the pre-combustion chamber, for implementing the above-described engine control method.

[0025] As a preferred embodiment of the aforementioned engine, the pre-combustion chamber includes a spherical first sub-chamber, a conical second sub-chamber, and a cylindrical third sub-chamber; along the height direction of the pre-combustion chamber, the first sub-chamber is connected to the large end of the second sub-chamber and is located above the second sub-chamber, and the third sub-chamber is connected to the small end of the second sub-chamber and is located below the second sub-chamber;

[0026] The air intake channel includes a sub-air intake channel communicating with the first sub-chamber; the sub-air intake channel is arc-shaped; along the height direction of the pre-combustion chamber, the opening of the sub-air intake channel faces downward, and the sub-air intake channel is located at the top of the first sub-chamber.

[0027] The beneficial effects of this invention are:

[0028] This invention provides an engine control method and an engine. The engine control method includes: determining the limiting crankshaft angle range corresponding to the start of scavenging in the pre-combustion chamber based on a preset injection pressure and a preset injection quantity; determining the conditions for starting scavenging in the pre-combustion chamber based on the temperature and pressure of the main combustion chamber, the preset injection pressure, and the limiting crankshaft angle range; and initiating scavenging in the pre-combustion chamber at the preset injection pressure and preset injection quantity. By employing this engine control method, the scavenging quality and efficiency of scavenging in the pre-combustion chamber can be effectively improved, as can the ignition efficiency and ignition reliability of the combustion gases within the pre-combustion chamber. Attached Figure Description

[0029] Figure 1 This is a cross-sectional view of the pre-combustion chamber structure provided in a specific embodiment of the present invention, viewed from a first perspective.

[0030] Figure 2 This is a cross-sectional view of the pre-combustion chamber structure provided in a specific embodiment of the present invention from a second perspective;

[0031] Figure 3 This is a schematic diagram of the pre-combustion chamber structure from a third-view perspective, provided in a specific embodiment of the present invention;

[0032] Figure 4 This is a simulation analysis comparison diagram of the residual exhaust gas volume at the end of scavenging between the pre-combustion chamber structure of the prior art and the pre-combustion chamber structure of the present invention.

[0033] Figure 5 This is a simulation analysis comparison diagram of the gas volume at the ignition moment between the pre-combustion chamber structure of the prior art and the pre-combustion chamber structure of the present invention.

[0034] Figure 6 This is a flowchart of an engine control method provided in a specific embodiment of the present invention;

[0035] Figure 7 These are temperature curves and pressure curves of the pre-combustion chamber provided in specific embodiments of the present invention;

[0036] Figure 8 This is a comparison chart of the residual exhaust gas mass fraction curves between the pre-combustion chamber structure of the prior art and the pre-combustion chamber structure of the present invention.

[0037] In the picture:

[0038] 1. Pre-combustion chamber body; 11. Pre-combustion chamber; 111. First sub-chamber; 112. Second sub-chamber; 113. Third sub-chamber; 12. Air intake passage; 121. Sub-air intake passage; 122. Annular passage; 13. Central mounting hole; 14. Vent hole;

[0039] 2. Main intake manifold. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0041] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0043] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0044] This invention provides an engine including a pre-combustion chamber structure, such as... Figure 1-3 As shown, the pre-combustion chamber structure includes a pre-combustion chamber body 1, which is provided with a pre-combustion chamber 11 and an air intake passage 12 communicating with the pre-combustion chamber 11. Scavenging gas is supplied to the pre-combustion chamber 11 through the air intake passage 12 to scaveng the pre-combustion chamber 11; fuel gas is also supplied to the pre-combustion chamber 11 through the air intake passage 12 to ignite the fuel gas in the main combustion chamber, thus achieving active ignition.

[0045] Preferably, such as Figure 1 and Figure 2As shown, the intake passage 12 includes multiple sub-intake passages 121, which are divided into multiple sub-intake passage groups. The multiple sub-intake passage groups are distributed at intervals along the height direction of the pre-combustion chamber 11. The multiple sub-intake passages 121 of each sub-intake passage group are distributed at intervals along the circumference of the pre-combustion chamber 11 and are all connected to the pre-combustion chamber 11. The number of sub-intake channels 121 is set to be multiple, and the multiple sub-intake channel groups are distributed at intervals along the height direction of the pre-combustion chamber 11, so that the coverage area of ​​the intake channel 12 is large, which can improve the scavenging effect of the pre-combustion chamber 11, thereby effectively reducing the amount of gas injected into the pre-combustion chamber 11 that leaks into the main combustion chamber and improving the working performance of the pre-combustion chamber structure. Secondly, the multiple sub-intake channels 121 of each sub-intake channel group are distributed at intervals along the circumference of the pre-combustion chamber 11, which can improve the scavenging uniformity, scavenging effect, scavenging efficiency and gas intake efficiency. When gas is injected into the pre-combustion chamber 11, it can effectively reduce the amount of gas leaking into the main combustion chamber and effectively improve the uniformity of gas distribution.

[0046] Further preferably, the multiple sub-intake channel groups are evenly spaced along the height direction of the pre-combustion chamber 11. The multiple sub-intake channels 121 of each sub-intake channel group are evenly spaced along the circumference of the pre-combustion chamber 11. This further improves the uniformity of scavenging gas and the uniformity of fuel gas distribution. In this embodiment, two sub-intake channel groups are exemplary, and the two sub-intake channel groups are spaced apart along the height direction of the pre-combustion chamber 11.

[0047] More preferably, such as Figure 1 and Figure 2 As shown, in two adjacent sub-intake channel groups along the height direction of the pre-combustion chamber 11, the multiple sub-intake channels 121 in one sub-intake channel group are staggered with the multiple sub-intake channels 121 in the other sub-intake channel group along the circumferential direction of the pre-combustion chamber 11. This can further increase the coverage of the sub-intake channels 121, thereby further improving the uniformity of scavenging gas and the uniformity of gas distribution. As an alternative, in two adjacent sub-intake channel groups along the height direction of the pre-combustion chamber 11, the multiple sub-intake channels 121 in one sub-intake channel group correspond one-to-one with the multiple sub-intake channels 121 in the other sub-intake channel group and are positioned in the same circumferential direction of the pre-combustion chamber 11.

[0048] Preferably, such as Figure 1 and Figure 2As shown, the sub-intake passage 121 is arc-shaped. Along the height direction of the pre-combustion chamber 11, the opening of the sub-intake passage 121 faces downwards. This ensures that the gas injected into the pre-combustion chamber 11 through each sub-intake passage 121 along the height direction of the pre-combustion chamber 11 is inclined downwards, further improving the scavenging effect and efficiency. Alternatively, the sub-intake passage 121 can be straight, with the angle between the direction of gas flow from the straight sub-intake passage 121 to the pre-combustion chamber 11 and the downward direction of the pre-combustion chamber 11 being greater than or equal to 90° and less than 180°. This ensures that the gas injected into the pre-combustion chamber 11 through each sub-intake passage 121 along the height direction of the pre-combustion chamber 11 is also inclined downwards, facilitating the discharge of exhaust gas generated in the previous cycle within the pre-combustion chamber 11.

[0049] More preferably, such as Figure 1 and Figure 2 As shown, along the top-to-bottom direction of the pre-combustion chamber 11, the included angles of the multiple sub-intake channel groups gradually increase. As the included angles of the multiple sub-intake channel groups gradually increase, the gas injected into the central region of the pre-combustion chamber 11 from each sub-intake channel group is distributed sequentially from top to bottom along the height direction of the pre-combustion chamber 11, thereby further improving the scavenging effect and scavenging efficiency. 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 top-to-bottom direction, the bottom-to-top direction, the height direction of the pre-combustion chamber 11, and the central axis of the pre-combustion chamber 11 are all parallel.

[0050] More preferably, the orifice diameter of the sub-intake channel 121 gradually decreases from its input end to its output end. It is understood that the cross-sectional area of ​​the sub-intake channel 121 perpendicular to its extension direction gradually decreases from its input end to its output end. This is to effectively increase the velocity of gas injected into the pre-combustion chamber 11 through the sub-intake channel 121, thereby further improving the scavenging effect and combustion efficiency. Alternatively, the orifice diameter of the sub-intake channel 121 may be uniform from its input end to its output end.

[0051] Among them, such as Figure 1 and Figure 2 As shown, the intake passage 12 also includes an annular passage 122 located within the pre-combustion chamber body 1, and the annular passage 122 is connected to each sub-intake passage 121 of each sub-intake passage group. This allows gas to be synchronously delivered into the pre-combustion chamber 11 through each sub-intake passage 121.

[0052] Specifically, such as Figure 1-3As shown, the pre-combustion chamber structure also includes an intake manifold 2, one end of which is connected to an annular channel 122, and the other end is used to connect to a scavenging gas source and a combustion gas source. This enables the delivery of scavenging gas and combustion gas into the pre-combustion chamber 11.

[0053] Preferably, the sum of the end face areas of the output ends of each sub-intake channel 121 is equal to the intake cross-sectional area of ​​the main intake pipe 2 perpendicular to its own extension direction, in order to avoid pressure loss caused by the transport of gas.

[0054] Preferably, in this embodiment, such as Figure 1 and Figure 2 As shown, the pre-combustion chamber 11 includes a spherical first sub-chamber 111, a conical second sub-chamber 112, and a cylindrical third sub-chamber 113. Along the height direction of the pre-combustion chamber 11, the first sub-chamber 111 communicates with the larger end of the second sub-chamber 112 and is located above the second sub-chamber 112, while the third sub-chamber 113 communicates with the smaller end of the second sub-chamber 112 and is located below the second sub-chamber 112. Along the height direction of the pre-combustion chamber 11, the intake passage 12 is located at the top of the first sub-chamber 111. That is, both the sub-intake passage 121 and the annular passage 122 are located at the top of the first sub-chamber 111.

[0055] In existing technologies, the gas flow dead zone in the pre-combustion chamber is mainly concentrated at the top. Therefore, the first sub-chamber 111 is spherical, and the inner wall of the sphere can guide the gas flow, effectively reducing the gas flow dead zone in the pre-combustion chamber 11 compared to existing technologies, thereby further improving the scavenging effect. The gas flow dead zone refers to a localized area in the pre-combustion chamber 11 where the gas essentially does not participate in the gas flow and only moves locally in place.

[0056] Specifically, in this embodiment, such as Figure 4 As shown, the left side is a simulation analysis diagram of the residual exhaust gas volume of the pre-combustion chamber structure before optimization at the end of scavenging, and the right side is a simulation analysis diagram of the residual exhaust gas volume of the pre-combustion chamber structure of the present invention at the end of scavenging. Figure 4 It is evident that the pre-combustion chamber structure on the right has significantly less dead zone for gas flow compared to the pre-combustion chamber structure on the left; secondly, the amount of residual exhaust gas in the area circled by the dashed line in the pre-combustion chamber structure on the right is significantly less than the amount of residual exhaust gas in the corresponding area in the pre-combustion chamber structure on the left.

[0057] Specifically, in this embodiment, such as Figure 5 As shown, the left side is a simulation analysis diagram of the gas volume at ignition time for the pre-combustion chamber structure before optimization, and the right side is a simulation analysis diagram of the gas volume at ignition time for the pre-combustion chamber structure of the present invention. Figure 5It is evident that, compared to the pre-combustion chamber structure on the left, the right pre-combustion chamber structure has significantly fewer dead zones in gas flow, and the gas is more evenly distributed within the pre-combustion chamber 11.

[0058] As an alternative, the pre-combustion chamber 11 includes a cylindrical first sub-chamber 111, a conical second sub-chamber 112, and a cylindrical third sub-chamber 113. Along the height direction of the pre-combustion chamber 11, the first sub-chamber 111 communicates with the larger end of the second sub-chamber 112 and is located above the second sub-chamber 112, while the third sub-chamber 113 communicates with the smaller end of the second sub-chamber 112 and is located below the second sub-chamber 112. Along the height direction of the pre-combustion chamber 11, the intake passage 12 is located at the top of the first sub-chamber 111.

[0059] Specifically, such as Figure 1-3 As shown, the top of the pre-combustion chamber body 1 is provided with a central mounting hole 13 communicating with the first sub-chamber 111. The central mounting hole 13 is used to install a spark plug to enable ignition of the gas in the pre-combustion chamber 11. Preferably, the central axis of the central mounting hole 13 is collinear with the central axis of the pre-combustion chamber 11. The annular channel 122 and multiple sub-intake channels 121 are distributed on the outer periphery of the central mounting hole 13.

[0060] Specifically, such as Figure 1-3 As shown, the bottom end of the pre-combustion chamber body 1 is provided with a vent 14 that communicates with the third sub-chamber 113, and the vent 14 is connected to the main combustion chamber of the engine. During scavenging, the exhaust gas in the pre-combustion chamber 11 flows through the vent 14 to the main combustion chamber and is discharged from the main combustion chamber. During ignition, the combustion gas ignited in the pre-combustion chamber 11 is injected into the main combustion chamber through the vent 14, igniting the combustion gas in the main combustion chamber to achieve active ignition.

[0061] Preferably, such as Figure 1-3 As shown, there are multiple vent holes 14, which are distributed at intervals 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. More preferably, the multiple vent holes 14 are evenly distributed at intervals along the circumference of the pre-combustion chamber 11 to further improve the uniformity of gas injection.

[0062] Specifically, in this embodiment, the scavenging gas source supplies air. The scavenging gas source is a separately installed air cylinder, and the main air inlet pipe 2 is used to connect to both the air cylinder and the fuel gas source. As an alternative, the scavenging gas source supplies fuel gas.

[0063] Specifically, in this embodiment, the fuel gas supplied by the gas source is methane. The gas source and the fuel gas source of the main combustion chamber are the same. In other embodiments, the fuel gas may also be hydrogen or other hydrocarbons.

[0064] The present invention also provides an engine control method for use in an engine. By employing this engine control method, the scavenging quality and efficiency of scavenging gas in the pre-combustion chamber 11 can be effectively improved, and the ignition efficiency and ignition reliability of igniting the combustion gas in the pre-combustion chamber 11 can also be effectively improved.

[0065] like Figure 6 As shown, the engine control method includes:

[0066] S100. Determine the limit crankshaft angle range corresponding to the start of scavenging when the pre-combustion chamber 11 begins scavenging based on the preset injection pressure and preset injection quantity.

[0067] Specifically, the preset injection pressure range is 7 bar to 10 bar. This preset injection pressure range is based on empirical data obtained from numerous previous experiments.

[0068] Specifically, the preset injection quantity ranges from (0.5% * total gas volume) to (1% * total gas volume). The total gas volume is the total amount of gas injected into the pre-combustion chamber 11 and the main combustion chamber in each working cycle of the engine; the volume of the pre-combustion chamber 11 accounts for 1% to 1.5% of the volume of the main combustion chamber. The preset injection quantity range is an empirical range obtained from a large number of previous tests.

[0069] It is understandable that for engines of different specifications, the selected preset injection pressure may be the same or different, and the selected preset injection quantity may be the same or different.

[0070] Specifically, step S100 includes: retrieving the crankshaft angle range for the start of scavenging from a table based on a preset injection pressure and a preset injection quantity. The table is formed by the preset injection pressure, preset injection quantity, and the crankshaft angle range for the start of scavenging. The table is an empirical table obtained from numerous prior experiments.

[0071] Based on the determined limit range of crankshaft angles for initiating scavenging, the crankshaft angle corresponding to the start of scavenging is limited to avoid starting scavenging in the pre-combustion chamber 11 too early or too late. This effectively ensures the scavenging effect in the pre-combustion chamber 11.

[0072] Understandably, the corresponding tables differ for different engine specifications. The crankshaft angle range for initiating scavenging may be the same or different depending on the preset injection pressure and preset injection quantity selected.

[0073] S200, based on the temperature of the main combustion chamber, the pressure of the main combustion chamber, the preset injection pressure, and the crankshaft angle range at the limit of the start of scavenging, determines the conditions for the start of scavenging in the pre-combustion chamber 11.

[0074] Specifically, step S200 includes:

[0075] The system determines whether the crankshaft angle is within the limit range for initiating scavenging; whether the temperature of the main combustion chamber is less than or equal to the set temperature; and whether the pressure difference is greater than or equal to the set scavenging pressure difference. Wherein, pressure difference = preset injection pressure - main combustion chamber pressure.

[0076] If the crankshaft angle is within the limit range of the crankshaft angle at which scavenging begins, the temperature of the main combustion chamber is less than or equal to the set temperature, and the pressure difference is greater than or equal to the set scavenging pressure difference, then the conditions for the pre-combustion chamber 11 to begin scavenging are met.

[0077] S300, scavenging begins in the pre-combustion chamber 11 with a preset injection pressure and preset injection quantity.

[0078] Specifically, when the pressure difference is greater than or equal to the set scavenging pressure difference, it indicates that the pressure in the main combustion chamber is low; when the temperature in the main combustion chamber is less than or equal to the set temperature, it indicates that the temperature in the main combustion chamber is also low. Therefore, starting scavenging in the pre-combustion chamber 11 when both the temperature and pressure in the main combustion chamber are low allows the scavenging gas injected into the pre-combustion chamber 11 to flow efficiently and smoothly into the main combustion chamber through the vent 14 after scavenging, and finally be discharged from the main combustion chamber. This effectively improves the scavenging effect and efficiency of scavenging the pre-combustion chamber 11.

[0079] In this embodiment, the scavenging gas is air. Scavenging the pre-combustion chamber 11 with air, compared to scavenging it with fuel gas, can effectively avoid fuel gas residue at the end of scavenging, thus facilitating control of the amount of fuel gas injected into the pre-combustion chamber 11 subsequently.

[0080] Specifically, the set temperature range is 600K to 800K. It is understood that the set temperature value is related to factors such as engine specifications, preset injection pressure, and preset injection quantity. For different engine specifications, preset injection pressures, and preset injection quantities, the set temperature value may be the same or different. The set temperature range is an empirical range obtained from extensive prior testing.

[0081] Specifically, the set scavenging pressure differential is 4 bar to 7 bar. It is understood that the set scavenging pressure differential is related to factors such as engine specifications, preset injection pressure, and preset injection quantity. For different engine specifications, preset injection pressures, and preset injection quantities, the set scavenging pressure differential may be the same or different. The set scavenging pressure differential range is based on empirical data obtained from extensive prior testing.

[0082] The process after step S300 also includes:

[0083] S400: Determine if the pressure difference is less than the set combustion pressure difference. If the pressure difference is less than the set combustion pressure difference, proceed to step S500.

[0084] S500, fuel is injected into the pre-combustion chamber 11 at a preset injection pressure and a preset injection quantity.

[0085] Specifically, when the pressure difference is less than the set intake pressure difference, it indicates that the pressure and temperature of the main combustion chamber will gradually increase, and the engine will gradually enter the compression stage. Therefore, when the set pressure difference is less than the set intake pressure difference, gas is injected into the pre-combustion chamber 11, which can effectively reduce the amount of gas leaking into the main combustion chamber, thereby effectively improving the ignition efficiency and ignition reliability of the gas in the pre-combustion chamber 11.

[0086] Specifically, the range for the intake-fuel pressure differential is set to (1 bar, 4 bar). That is, the minimum value of the intake-fuel pressure differential is greater than 1 bar, and the maximum value is less than 4 bar. It is understood that the set value of the intake-fuel pressure differential is related to factors such as engine specifications, preset injection pressure, and preset injection quantity. For different engine specifications, preset injection pressures, and preset injection quantities, the set value of the intake-fuel pressure differential may be the same or different. The set range for the intake-fuel pressure differential is an empirical range obtained from extensive prior testing.

[0087] Preferably, in this embodiment, the set value of the combustion pressure difference is the same as the set value of the scavenging pressure difference. This ensures that when scavenging of the pre-combustion chamber 11 is stopped, gas injection into the pre-combustion chamber 11 begins simultaneously. In other embodiments, the set value of the combustion pressure difference may also be less than the set value of the scavenging pressure difference. This ensures that gas injection into the pre-combustion chamber 11 begins only after a certain period of time has elapsed since scavenging has stopped.

[0088] Specifically, step S500 is followed by:

[0089] Following S600, the following further includes: when the pressure difference is less than or equal to 1 bar, controlling the cessation of gas injection into the pre-combustion chamber 11. Because the pressure in the pre-combustion chamber 11 fluctuates and is unstable when the pressure difference is less than or equal to 1 bar, this can easily lead to unstable gas injection into the pre-combustion chamber 11. Therefore, when the pressure difference is less than or equal to 1 bar, controlling the cessation of gas injection into the pre-combustion chamber 11 is implemented.

[0090] By adopting this engine control method, the scavenging effect and efficiency of scavenging the pre-combustion chamber 11 can be effectively improved, and the ignition efficiency and reliability of igniting the gas in the pre-combustion chamber 11 can also be effectively improved.

[0091] Specifically, in this embodiment, an exemplary example is taken with a preset injection pressure of 8 bar, a preset injection quantity of (1% * total fuel volume), a set temperature of 600 K, and a set pressure difference of 4 bar. The crankshaft angle range for scavenging, starting from the limit selected in the table using the preset injection pressure, is -345°CA to -180°CA. Figure 7 It can be seen that when the crankshaft angle is -345°CA, scavenging begins in the pre-combustion chamber 11; when the crankshaft angle is -180°CA, scavenging stops in the pre-combustion chamber 11 and gas injection begins; when the crankshaft angle is -85°CA, gas injection stops in the pre-combustion chamber 11.

[0092] Specifically, in this embodiment, combined with Figure 7 and Figure 8 It can be seen that the residual exhaust gas mass fraction decreased by approximately 0.01% at the end of the scavenging process in the pre-combustion chamber 11, thus improving the scavenging effect. The exhaust gas mainly consists of carbon dioxide.

[0093] Specifically, in this embodiment, the amount of gas in the pre-combustion chamber 11 remains essentially unchanged when the gas injection stops. Equivalent combustion occurs in the pre-combustion chamber 11.

[0094] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An engine control method, characterized in that, include: The limit crankshaft angle range at which scavenging begins when the pre-combustion chamber (11) begins is determined based on the preset injection pressure and preset injection quantity. Based on the temperature of the main combustion chamber, the pressure of the main combustion chamber, the preset injection pressure, and the crankshaft angle range at the limit start of scavenging, the conditions for starting scavenging in the pre-combustion chamber (11) are determined. The pre-combustion chamber (11) is scavenged with the preset injection pressure and the preset injection amount. The steps for determining the conditions for starting scavenging in the pre-combustion chamber (11) based on the temperature and pressure of the main combustion chamber, the preset injection pressure, and the maximum crankshaft angle range for starting scavenging include: Determine if the crankshaft angle is within the range of the limit start scavenging crankshaft angle; determine if the temperature of the main combustion chamber is less than or equal to the set temperature; determine if the pressure difference is greater than or equal to the set scavenging pressure difference; the pressure difference = preset injection pressure - pressure of the main combustion chamber; If the crankshaft angle is within the range of the crankshaft angle at the limit of the start of scavenging, the temperature of the main combustion chamber is less than or equal to the set temperature, and the pressure difference is greater than or equal to the set scavenging pressure difference, then the conditions for the start of scavenging in the pre-combustion chamber (11) are met.

2. The engine control method according to claim 1, characterized in that, The steps for determining the limit crankshaft angle range corresponding to the start of scavenging in the pre-combustion chamber (11) based on the preset injection pressure and preset injection quantity include: The limit start scavenging crankshaft angle range is obtained from the table based on the preset injection pressure and the preset injection quantity; wherein the table is formed by the preset injection pressure, the preset injection quantity and the limit start scavenging crankshaft angle range.

3. The engine control method according to claim 1, characterized in that: The set temperature range is 600K to 800K; The range of the set scavenging pressure difference is 4 bar to 7 bar.

4. The engine control method according to any one of claims 1-3, characterized in that: The preset injection pressure ranges from 7 bar to 10 bar. The preset injection quantity ranges from (0.5% * total gas volume) to (1% * total gas volume). The total gas volume is the total amount of gas injected into the pre-combustion chamber (11) and the main combustion chamber in each working cycle of the engine; the volume of the pre-combustion chamber (11) accounts for 1% to 1.5% of the volume of the main combustion chamber.

5. The engine control method according to claim 4, characterized in that: The preset injection pressure is 8 bar, the preset injection quantity is (1% * total fuel volume), and the crankshaft angle range for the start of the ultimate scavenging is -345°CA to -180°CA.

6. The engine control method according to any one of claims 1-3, characterized in that, After scavenging the pre-combustion chamber (11) with the preset injection pressure and the preset injection quantity, the following steps are also included: Determine whether the pressure difference is less than the set combustion pressure difference; the pressure difference = preset injection pressure - pressure of the main combustion chamber; if the pressure difference is less than the set combustion pressure difference, then start injecting fuel into the pre-combustion chamber (11) with the preset injection pressure and the preset injection amount.

7. The engine control method according to claim 6, characterized in that: The range of the set intake pressure differential is (1 bar, 4 bar).

8. An engine, the engine comprising a pre-combustion chamber structure, the pre-combustion chamber structure comprising a pre-combustion chamber body (1), the pre-combustion chamber body (1) having a pre-combustion chamber (11) and an intake passage (12) communicating with the pre-combustion chamber (11), characterized in that, Used to implement the engine control method according to any one of claims 1-7.

9. The engine according to claim 8, characterized in that, The pre-combustion chamber (11) includes a spherical first sub-chamber (111), a conical second sub-chamber (112), and a cylindrical third sub-chamber (113); along the height direction of the pre-combustion chamber (11), the first sub-chamber (111) is connected to the large end of the second sub-chamber (112) and is located above the second sub-chamber (112), and the third sub-chamber (113) is connected to the small end of the second sub-chamber (112) and is located below the second sub-chamber (112); The air intake channel (12) includes a sub-air intake channel (121) communicating with the first sub-chamber (111); the sub-air intake channel (121) is arc-shaped; along the height direction of the pre-combustion chamber (11), the opening of the sub-air intake channel (121) faces downward, and the sub-air intake channel (121) is located at the top of the first sub-chamber (111).

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