CN113719341B

CN113719341B - Jet-compression ignition combustion system of multi-partition combustion chamber

Info

Publication number: CN113719341B
Application number: CN202110876385.8A
Authority: CN
Inventors: 王必璠; 李智; 张宏飞; 程伟; 安涛; 王志; 赵自庆; 蔡开源; 王巍
Original assignee: Tsinghua University; Dongfeng Commercial Vehicle Co Ltd
Current assignee: Tsinghua University; Dongfeng Commercial Vehicle Co Ltd
Priority date: 2021-07-29
Filing date: 2021-07-29
Publication date: 2022-11-29
Anticipated expiration: 2041-07-29
Also published as: CN113719341A

Abstract

The invention discloses a jet-compression ignition combustion system of a multi-partition combustion chamber, which comprises a cylinder cover, a nozzle, a jet chamber and a spark plug, wherein the nozzle is arranged in the cylinder cover; a fuel supply channel is arranged on the cylinder cover; the nozzle is arranged on the side wall of the cylinder cover; the jet chamber is arranged on the cylinder cover and is coaxial with the cylinder; the spark plug is communicated with the jet flow chamber and is positioned right above the jet flow chamber; the jet chamber is provided with a plurality of jet holes; one end of the fuel supply channel is communicated with the nozzle, and the other end of the fuel supply channel is communicated with the jet chamber through one or more fuel inlets arranged on the jet chamber; the cylinder cover is connected with a cylinder sleeve, and a piston is arranged in the cylinder sleeve; the top of the piston is provided with a pit and a concave ring groove; the center of the pit is over against the axis of the jet flow chamber; the concave ring groove is located the outside of pit, and is coaxial with the pit. The invention reduces the possibility of detonation induced by spontaneous combustion of the tail end gas mixture, and is beneficial to improving the structural stability, the anti-detonation performance and the reliability of the engine.

Description

Jet-compression ignition combustion system of multi-partition combustion chamber

Technical Field

The invention belongs to the technical field of automobile engines, relates to a design method of a combustion system in an internal combustion engine and an organization method of a combustion mode, and particularly relates to a jet flow-compression ignition combustion system of a multi-partition combustion chamber.

Background

For the traditional ignition type gasoline engine, the technical route of equivalence ratio combustion is adopted for combustion, and single-point flame propagation is relied on; the method has two limit values, firstly, the equivalence ratio combustion is not beneficial to the improvement of the thermal efficiency, and in order to realize further energy conservation and emission reduction of the internal combustion engine, the technical route of the internal combustion engine combustion is bound to adopt lean combustion; secondly, spark ignition depends on the propagation speed of flame, the propagation speed of flame of a single point restricts the improvement of the combustion isochoric degree of the engine, the improvement of the thermal efficiency of the engine is not facilitated, and under the future lean-burn condition, the propagation speed of flame is further reduced, and the combustion isochoric degree and the combustion stability are further reduced. In order to support the technical development direction of future advanced engines, the ignition energy of the internal combustion engine needs to be further improved, and a novel high-energy ignition mode is adopted; jet ignition is an effective way of ignition. The jet ignition adopts multiple jets to ignite the mixture in the cylinder, and the multiple jets induce the propagation of multiple flame surfaces in the cylinder. However, the compression of the multiple flame surfaces promotes the end mixture to be more easily self-ignited, and the detonation phenomenon with different intensities is generated.

Chinese patent "a jet valve controlled prechamber ignition internal combustion engine", publication No. CN112879145A, publication No. 2021.06.01, discloses a jet valve controlled prechamber ignition internal combustion engine, which sets a jet valve in the air flow passage between the prechamber and the main combustion chamber, before the pilot mixture is ignited by the spark plug in the prechamber, the jet valve is closed, the air passage leading from the prechamber to the main combustion chamber is cut off, after the pilot mixture is ignited by the spark plug in the prechamber and burned for a while, the pilot mixture reaches the required high temperature and high pressure state, the jet valve is opened at the optimum timing, so that the high temperature and high pressure gas in the prechamber is jetted to the main combustion chamber and ignites the mixture in the main combustion chamber. The jet flow passage is communicated with the main combustion chamber from the precombustion chamber, and the passive air intake passage is communicated with the precombustion chamber from the main combustion chamber; the jet flow control valve plays a role in opening and closing a jet flow channel; the mixture directly enters the cylinder.

Chinese patent "turbulent jet ignition prechamber combustion system of a spark ignition engine", publication No. CN106194395A, publication No. 2016.12.07, discloses an ignition system for an internal combustion engine having at least one combustion chamber, wherein the ignition system comprises a housing, an ignition device, an injector and a prechamber having a nozzle arranged spaced apart from a proximal portion of the prechamber. The igniter portion of the ignition device and the nozzle of the injector are operably supported in the proximal portion of the prechamber and are disposed flush therewith. The igniter partially ignites the fuel in the prechamber so that partially combusted prechamber products are forced through the apertures in the prechamber and are extinguished, but are distributed through the combustion chamber to ignite a main fuel charge therein.

Chinese patent "a lean burn engine heat jet mechanism and combustion system thereof", publication No. CN113006927A, publication No. 2021.06.22, improves the gas fuel heat jet engine mechanism, and separately extracts the mixed gas with higher concentration at the outlet end of the fuel injector in the air intake passage, and supplies the mixed gas to the precombustion chamber through the camshaft and the valve mechanism, when the engine needs to ignite, the spark plug in the precombustion chamber ignites the rich mixed gas in the precombustion chamber, and injects the high-temperature burned compound in the precombustion chamber into the combustion chamber through the pressure difference between the precombustion chamber and the combustion chamber, thereby igniting the lean mixed gas in the combustion chamber, and effectively simplifying the preparation process of the mixed gas in the precombustion chamber of the heat jet engine. The invention also effectively inhibits detonation and harmful pollutant discharge while further improving the combustion stability of the thermal jet engine by exhaust gas recirculation and air intake layering technologies.

Chinese patent "compression ignition jet flow ignition combustion system and combustion control method", publication No. CN110925077A, publication No. 2020.03.27, discloses a compression ignition jet flow ignition combustion system and combustion control method, in which a manifold injector and a direct injection injector jointly form a dual injection structure, and a spark plug is not required to be provided in the combustion system. The injection port of a manifold injector of the combustion system is connected with an air inlet channel; the jet chamber is arranged in the main combustion chamber, a jet orifice of the direct injection oil injector is connected with the jet chamber, and the jet chamber is used for enabling fuel oil sprayed by the direct injection oil injector to be subjected to compression ignition to form compression ignition fuel gas and respectively dispersing the compression ignition fuel gas into the main combustion chamber. The combustion system does not need to change a complex structure on the basis of the existing engine, has low cost, and ensures stable combustion and strong robustness; compared with the traditional flame jet combustion mode in the prior art, the combustion temperature is lower, the emission of nitrogen oxides in the engine is reduced, the load of a lean burn catalyst is lightened, and the time-sharing, partition and controllable spontaneous combustion of a jet chamber and a main combustion chamber is realized.

The jet fuel of the patent either directly enters the cylinder or adopts a double-injection structure through an overhead design.

For a side jet ignition system arranged on a traditional engine cylinder cover, the difficulty is how to consider that the structure of the existing parts is not greatly changed and the requirement of providing fuel in a transient state can be met.

Chinese patent "a direct-injection diesel lip jet combustion system", publication No. CN112324556A, publication No. 2021.02.05, discloses a direct-injection diesel lip jet combustion system, which includes an oil injector and a combustion chamber composed of a diesel cylinder head, a cylinder liner and a piston; the fuel injector sprays high-pressure fuel into the combustion chamber in a mist form in a multi-fuel-bundle mode; the top surface of the piston is a revolving body taking a piston shaft as a rotation center; the outline of the revolving body is formed by connecting the bottom surface of the combustion chamber outer area, a flow distribution ridge, a jet flow wall, a jet flow platform and the bottom surface of the combustion chamber inner area in a smooth transition mode in sequence; the jet flow platform is formed by connecting a jet flow lip and a jet flow lip back in a smooth transition manner; the combustion chamber is divided into a combustion chamber inner area, a combustion chamber middle area and a combustion chamber outer area; the oil beam collides with a flow dividing ridge arranged on the top surface of the piston to generate first separation, and the fuel oil is divided into two parts of inward movement and outward movement; the fuel oil moving inwards moves towards the center direction of the combustion chamber in a clockwise direction by taking the right half side combustion chamber as a reference, and then enters the combustion chamber in a back rotating mode through the bottom surface of the inner region of the combustion chamber, the fuel oil moving outwards moves to a jet flow table along a jet flow wall arranged on the top surface of a piston, fuel oil jet flow is generated at a jet flow lip, the fuel oil is peeled off from the wall surface to form high-speed jet flow in a spatial distribution mode, the fuel oil which is peeled off from the wall surface and moves at high speed flows in the air in a diffusion mode, surrounding air is continuously sucked until the fuel oil collides with the bottom surface of a cylinder cover, secondary separation is generated after the collision, a part of the separated fuel oil moves towards the center direction of the combustion chamber in an anticlockwise direction, the fuel oil enters the middle combustion chamber after passing through the bottom surface of the cylinder cover and then rotates towards the center direction of the combustion chamber, the other part of the fuel oil moves away from the center direction of the combustion chamber in a clockwise direction, and sequentially passes through the bottom surface of the cylinder cover, the bottom surface of the combustion chamber in the middle region and the jet flow chamber and the jet flow lip and then rotates into the outer region of the combustion chamber, so that the combustion chamber in the whole combustion chamber is realized in the whole combustion chamber.

Chinese patent "direct injection internal combustion engine with double cone angle for producing a fuel mixture in a dual zone combustion chamber with low compression ratio" and method of use thereof ", publication No. CN107076007A, publication No. 2017.08.18, discloses a compression ignition direct injection internal combustion engine comprising at least one cylinder, a cylinder head carrying a fuel injection means, a piston sliding in the cylinder, a combustion chamber bounded on one side by an upper surface of the piston, the piston comprising a protrusion extending in the direction of the cylinder head and arranged in the center of a concave bowl-shaped cavity with at least two mixing zones, the injection means injecting fuel in at least two fuel injection layers with different stream angle, an upper stream layer with injection axis C2 for zone (Z1) and an upper stream layer with injection axis C2 for zone (Z2), the fuel injector comprising at least two rows of injection holes arranged above each other, and the number of holes per row (Ninf, nsp) being greater than or equal to-4.ns 14 and less than or equal to Ns 4.18 for the lower row.

The prior engine mainly comprises a spark ignition gasoline engine and a compression ignition diesel engine, and the design of a combustion system is optimized mainly from the aspects of a piston, a cylinder cover, an air inlet channel, a fuel injector position, a spark plug position and the like. And the design scheme aiming at the novel jet flow-compression ignition type combustion system is lacked, and the existing design scheme of the traditional gasoline engine and the traditional diesel engine is adopted, so that the strong knocking is caused due to the mismatching of the structure and the combustion mode of the combustion system. This gives the possibility of damage to the structure of the engine. The traditional structural design can not be matched with the current novel combustion mode, so that the structure of the combustion system needs to be matched with the characteristics of the combustion mode.

The prior engine mainly comprises a spark ignition gasoline engine and a compression ignition diesel engine, and the design of a combustion system is optimized mainly from the aspects of a piston, a cylinder cover, an air inlet channel, a fuel injector position, a spark plug position and the like. And the design scheme aiming at a novel jet flow-compression ignition type combustion system is lacked, and the design scheme of the traditional gasoline engine and the traditional diesel engine is adopted, so that strong knocking is caused due to the mismatching of the structure and the combustion mode of the combustion system. This may cause damage to the structure of the engine. The traditional structural design can not be matched with the current novel combustion mode, so that the structure of the combustion system needs to be matched with the characteristics of the combustion mode.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a jet flow-compression ignition combustion system of a multi-partition combustion chamber, which eliminates tail end mixed gas, reduces the occurrence tendency of knocking, is favorable for expanding the load of an engine and realizes a jet flow compression ignition combustion mode.

In order to achieve the purpose, the invention designs a jet flow-compression ignition combustion system of a multi-partition combustion chamber, which is characterized in that: comprises a cylinder cover, a nozzle, a jet chamber and a spark plug; a fuel supply channel is arranged on the cylinder cover; the nozzle is arranged on the side wall of the cylinder cover; the jet chamber is arranged on the cylinder cover and is coaxial with the cylinder; the spark plug is communicated with the jet flow chamber and is positioned right above the jet flow chamber; the jet chamber is provided with a plurality of jet holes; one end of the fuel supply channel is communicated with the nozzle, and the other end of the fuel supply channel is communicated with the jet chamber through one or more fuel inlets arranged on the jet chamber; the cylinder cover is connected with a cylinder sleeve, and a piston is arranged in the cylinder sleeve;

the top of the piston is provided with a pit and a concave ring groove; the center of the pit is over against the axis of the jet flow chamber; the concave ring groove is located the outside of pit, and is coaxial with the pit.

Preferably, the concave pit is a spherical cap.

Preferably, the maximum diameter of the pit is 30-50% of the diameter of the piston.

Preferably, the depth of the concave pit is 15mm to 50mm.

Preferably, the maximum diameter of the concave ring groove is 50-90% of the diameter of the piston.

Preferably, the inner side wall surface of the concave ring groove is tangent to the jet flow stream direction at the top dead center position of the engine.

Preferably, the volume of the jet chamber is 1-3% of the volume of the main combustion chamber.

Preferably, a plurality of uniformly distributed first jet holes are axially arranged at the bottom of the jet chamber, and the included angle between the injection direction of the first jet holes and the axis of the jet chamber is 45-75 degrees.

Further preferably, the aperture of the first jet hole is 1 mm-2 mm.

Further preferably, 4 to 8 first jet holes are provided.

Preferably, a coaxial second jet hole is formed in the middle of the bottom of the jet chamber, and the injection direction of the second jet hole is coaxial with the axis of the jet chamber.

Further preferably, the aperture of the second jet hole is 0.5 mm-1 mm.

Preferably, the axis of the fuel supply passage is coplanar with the axis of the fuel inlet.

Further preferably, the diameter of the fuel inlet is 0.5mm to 1.5mm.

Further preferably, the fuel supply passage communicates with the jet chamber through a fuel inlet, and the fuel supply passage is coaxial with the fuel inlet.

Further preferably, the fuel supply passage communicates with the jet chamber through a plurality of fuel inlets; a groove is arranged on the cylinder cover which is contacted with the plurality of fuel inlets; the fuel supply passage communicates with the plurality of fuel inlets through the groove.

Still further preferably, the groove centerline, the axis of the fuel feed passage, and the axes of the plurality of fuel inlets are coplanar.

Still more preferably, the diameter of the groove is 0.5mm to 2.0mm.

Preferably, the recess is an annular groove, the fuel supply passage is a straight hole and a center line of the fuel supply passage passes through a center of the annular groove.

Preferably, the plurality of fuel inlets are uniformly distributed, and the axes of the plurality of fuel inlets are perpendicularly intersected with the axis of the jet flow chamber.

Preferably, the aperture diameter of the plurality of fuel inlets increases as the distance the fuel travels within the groove increases.

As another preferred scheme, the groove is a rotary groove; one end of the rotary groove is communicated with the first fuel inlet and the fuel supply channel at the same time, and the other end of the rotary groove is communicated with the last fuel inlet.

Preferably, the centre line of the fuel supply channel is arc-shaped, and a section close to the rotary groove is tangent to the outer wall of the jet chamber.

The invention has the beneficial effects that: the invention reduces the possibility of knocking induced by the spontaneous combustion of the tail end gas mixture, and is beneficial to improving the structural stability, the anti-knock property and the reliability of the engine. The cylinder wall-oriented induced jet flow is beneficial to eliminating sources of unburned hydrocarbon at the tail end and reducing the emission of hydrocarbon, and meanwhile, the compression ignition is introduced into the combustion system, so that the combustion rate and the isochoricity under lean combustion are improved, and the thermal efficiency is improved.

Drawings

FIG. 1 is a schematic view of the structure of the intake side of the cylinder head according to the present invention

FIG. 2 is a schematic view of the exhaust side structure of the cylinder head of the present invention

FIG. 3 is a schematic perspective view of the jet chamber assembly of the present invention

FIG. 4 is a schematic view of the split side-mounted jet ignition system of the present invention

FIG. 5 is a schematic view of a single orifice side fuel supply of the present invention

FIG. 6 shows a porous side-mounted fuel supply embodiment of the invention

FIG. 7 is a porous side-on-side fuel supply embodiment of the invention

FIG. 8 is a schematic diagram of the fuel supply passage of the present invention applied to a side-mounted jet ignition system

FIG. 9 is a schematic structural view of a fuel supply passage fuel pipe body of the present invention applied to a side-mounted jet ignition system

FIG. 10 is a schematic view of a jet-compression ignition combustion system for a multi-zone combustion chamber according to the present invention

Detailed Description

The technical solutions of the present invention (including the preferred ones) are described in further detail below by way of fig. 1 to 10 and enumerating some alternative embodiments of the present invention. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.

In the description of the present invention, "a plurality" means two or more unless otherwise specified; the terms "upper", "lower", "left", "right", "inner", "outer", "front", "rear", "head", "tail", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In addition, in the description of the present invention, the terms "mounted," "connected," and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

The invention relates to a fuel supply structure of a side jet ignition system, which is characterized in that: comprises a cylinder cover, a nozzle and a jet chamber installation body;

the jet chamber mounting body is arranged on the cylinder cover and is coaxial with the cylinder;

the jet chamber installation body is provided with a jet chamber, and the jet chamber is provided with a plurality of jet holes;

the cylinder cover between the two air channel openings is provided with a slender hole, one end of the slender hole is communicated with the jet flow chamber, and the other end of the slender hole is communicated with the nozzle.

Preferably, the elongated hole is a straight hole.

Preferably, the aperture of the elongated hole is 0.5 mm-1.0 mm. The aperture of the jet fuel elongated hole on the cylinder cover must be small enough to ensure that the total volume of the injected fuel passing path is small enough, so that the transient response of fuel injection can be ensured, and the working requirement of the jet ignition combustion system is met.

Preferably, the device further comprises a nozzle mounting body fixed with the cylinder cover, and the nozzle is mounted on the nozzle mounting body through a nozzle mounting pressing plate.

As shown in fig. 1 to fig. 3, the fuel supply structure of the side jet ignition system designed by the invention comprises a cylinder cover 1, a nozzle 2 and a jet chamber installation body 4;

the arrangement positions of the jet flow fuel elongated holes 3 can be designed according to the number of the valves (two valves or four valves) of the cylinder cover, the specific arrangement forms (parallel, rhombic, rectangular and the like) of the air inlet and outlet channels on the cylinder cover 1, the arrangement positions of the bowl-shaped plugs and the bolts on the cylinder cover and other specific structures.

That is to say the inlet for the jet ignition fuel supply may be arranged on the inlet side of the cylinder head, but also on the outlet side of the cylinder head. In the arrangement structure with the cylinder cover intake and exhaust sides as fuel inlets, according to the arrangement form (the number of valves, the arrangement of rhombic valves, the arrangement of parallel valves and the like) of intake and exhaust gas passages of a traditional engine on the cylinder cover, a jet ignition type fuel supply passage can pass between two intake passage outlets of the cylinder cover, between one intake passage outlet and one exhaust passage outlet or between two exhaust passage outlets.

According to the usual form of conventional head construction and to facilitate control of the gas temperature and pressure of the jet fuel, it is generally recommended to arrange as far as possible between the two inlet ports 5 an elongated hole 3 designed for the inlet of the jet fuel. Of course, if the position between two air inlet ports is limited by the structure and space of the engine and the cab, the position between two air inlet ports can be defined as the position between one air inlet port and one air outlet port or the position between two air outlet ports.

The nozzle 2 is mounted on the cylinder head 1 by a nozzle mounting body 7, specifically, a nozzle mounting body 8 is mounted on a cylinder head side wall on an intake side or an exhaust side by bolts, and the fuel nozzle 2 for injecting jet fuel is mounted on the nozzle mounting body 7 by a nozzle mounting pressing plate 6.

The diameter of the elongated hole 3 for the jet fuel to flow into in the invention must be small enough to ensure that the total volume of the path through which the jet fuel passes is small enough to meet the transient response in the working process of the jet combustion system and the working requirement of the jet ignition combustion system.

Meanwhile, the pressure and the temperature of the indoor fuel need to calibrate and correct the influence of the temperature of the wall of the elongated hole on the actual parameters of the relevant injection in different air passage outlet schemes, so that different influences of different structural forms on the work of the jet ignition system are eliminated, and the application range and the use effect of the invention are improved.

This patent combines the concrete structural style of traditional engine cylinder lid, has proposed the jet fuel of side formula jet ignition system and has transmitted the solution to the efflux room by the cylinder lid bottom surface through the spatial structure between two valves, ingenious structure and the space that has utilized traditional engine cylinder lid, realized the jet fuel supply demand that side formula jet ignition system needs under the prerequisite that does not change current traditional cylinder lid structure.

The invention fully utilizes the existing engine cylinder cover structure, and realizes the requirement that the side jet ignition system supplies fuel through the slender inner hole of the cylinder cover on the premise of low additional cost, so that the mass production and the sale of the engine products of the side jet ignition system become possible.

The invention fully utilizes the structural design and layout design basis of the existing engine, reasonably and skillfully utilizes the structural space of the engine cylinder cover, and realizes the fuel supply function by designing the elongated hole structure on the cylinder cover bottom plate and passing through the space between the outlets of the two air passages. The universality of parts is very high, the manufacture and assembly of key parts also meet the requirements of mass production and sale of products, and the operation and the implementation are very good.

The jet fuel elongated hole on the cylinder cover can ensure the safety of fuel injection work, simultaneously, the volume for the jet fuel to pass through is smaller, the transient characteristic of the jet fuel is effectively ensured, and the problem of the working stability of a jet fuel ignition system is effectively solved.

The position of the arrangement of the elongated holes 3 is described above and in the following, how the fuel enters the inlet flow chamber is described in detail.

The invention designs a split side jet ignition system, which is characterized in that: comprises a cylinder cover, a nozzle, a jet chamber and a spark plug; a fuel supply channel is arranged on the cylinder cover; the nozzle is arranged on the side wall of the cylinder cover; the jet chamber is arranged on the cylinder cover and is coaxial with the cylinder; the spark plug is communicated with the jet flow chamber and is positioned right above the jet flow chamber; the jet chamber is provided with a plurality of jet holes; one end of the fuel supply channel is communicated with the nozzle, and the other end of the fuel supply channel is communicated with the jet chamber through one or more fuel inlets arranged on the jet chamber.

Further preferably, the diameter of the fuel inlet is 0.5mm to 1.5mm.

Still further preferably, the groove centerline, the axis of the fuel supply passage, and the axis of the plurality of fuel inlets are coplanar.

Still more preferably, the diameter of the groove is 0.5mm to 2.0mm.

Preferably, the aperture diameter of the plurality of fuel inlets increases as the distance fuel travels within the groove increases.

As another preferable scheme, the groove is a rotary groove; one end of the rotary groove is communicated with the first fuel inlet and the fuel supply channel at the same time, and the other end of the rotary groove is communicated with the last fuel inlet.

Preferably, the centre line of the fuel supply channel is an arc line, and a section close to the rotating groove is tangential to the outer wall of the jet flow chamber.

Preferably, the cylinder head is provided with a plurality of air passage openings for exhaust and/or intake, and the fuel supply passage is provided on the cylinder head between the two air passage openings.

Preferably, the fuel supply passage has a diameter of 0.5mm to 1.0mm.

Preferably, the volume of the jet chamber is 1% -3% of the volume of the main combustion chamber at the top dead center of the engine.

Preferably, a plurality of uniformly distributed first jet holes are axially formed in the bottom of the jet chamber.

Further preferably, the aperture of the first jet hole is 1 mm-2 mm.

Preferably, a coaxial second jet hole is formed in the middle of the bottom of the jet chamber.

Further preferably, the aperture of the second jet hole is 0.5 mm-1 mm.

As shown in fig. 4 to 7, the split side jet ignition system designed by the invention comprises a cylinder head 1, a nozzle 2, a jet chamber 9 and a spark plug 10; a fuel supply channel 3' is arranged on the cylinder head 1; the nozzle 2 is arranged on the side wall of the cylinder cover; the jet chamber 9 is arranged on the cylinder cover 1 and is coaxial with the cylinder; the spark plug 10 is communicated with the jet flow chamber 9 and is positioned right above the jet flow chamber 9; the jet chamber 9 is provided with a plurality of jet holes; the fuel supply channel 3' communicates at one end with the nozzle 2 and at the other end with the jet chamber via one or more fuel inlets 14 provided in the jet chamber 9.

The split side jet ignition system comprises a cylinder sleeve 8, a piston 12, a connecting rod 13, a main combustion chamber 11, a spark plug 10, a cylinder cover 1, a fuel supply channel 3', a nozzle 2 and a jet chamber 9.

The spark plug 10 and the jet flow chamber 9 are designed in an integrated mode, the spark plug 10 is located in the middle of the jet flow chamber 9, and the jet flow chamber 9 is installed in the middle of the cylinder cover 1, so that the axial jet flow spray holes are consistent in distance from the wall of an engine cylinder; the nozzle 2 is fixed to one side of the cylinder head 1 and communicates with the jet chamber 9 through a fuel supply passage 3'. The fuel supply scheme can adopt a gas fuel, a liquid fuel or a liquid fuel with gas assistance, the diameter of a fuel supply channel 3' is 0.5 mm-1 mm, the volume of a jet flow chamber 9 is about 1% -3% of the volume of a main combustion chamber 11 when the top dead center of an engine is reached, a plurality of first jet flow holes which are uniformly distributed are axially arranged at the bottom of the jet flow chamber 9, and the hole diameter is 1 mm-2 mm; a second jet hole with the aperture of 0.5 mm-1 mm is arranged in the middle of the bottom of the jet chamber 9; one or more fuel inlets 14 are arranged on the side wall of the jet chamber 9;

when a fuel inlet is provided, as shown in FIG. 5, the fuel supply passage 3' is connected to the fuel inlet 14, and the fuel inlet 14 has a diameter of 0.5mm to 1.5mm. The same diameter as the fuel supply passage may be employed.

As shown in fig. 6 and 7, when a plurality of fuel inlets 14 are provided, two embodiments employ four fuel inlets, and the fuel supply passage 3' is connected to the fuel inlets 14 via the grooves 15; the groove central line, the axis of the fuel supply channel and the axes of the plurality of fuel inlets are coplanar; the diameter of the fuel inlet is 0.5 mm-1.5 mm.

As shown in fig. 6, an annular groove is employed, the fuel supply passage 3 'is a straight hole and the center line of the fuel supply passage 3' passes through the center of the annular groove. The fuel inlets 14 are uniformly distributed and the axes of the fuel inlets are perpendicularly intersected with the axis of the jet flow chamber 9.

Specifically, a first fuel inlet 14a, a second fuel inlet 14b, a third fuel inlet 14c, and a fourth fuel inlet 14d are provided, and the second fuel inlet 14b and the third fuel inlet 14c are arranged symmetrically with respect to the axes of the first fuel inlet 14a and the fourth fuel inlet 14 d.

The pore size of the plurality of fuel inlets increases as the distance the fuel travels within the groove 15 increases.

Specifically, the diameter of the first fuel inlet 14a is smaller than the diameter of the second fuel inlet 14 b; the diameters of the second fuel inlet 14b and the third fuel inlet 14c are equal because the second fuel inlet 14b and the third fuel inlet 14c are designed symmetrically and the distance traveled by the fuel is equal; the diameter of the second fuel inlet 14b and the diameter of the third fuel inlet 14c are both smaller than the diameter of the fourth fuel inlet 14 d.

As shown in fig. 7, the groove 15 is a rotary groove; one end of the rotary groove is simultaneously communicated with the first fuel inlet and the fuel supply channel 3', and the other end is communicated with the last fuel inlet. In this example, four fuel inlets are provided, a first fuel inlet 14a ', a second fuel inlet 14b', a third fuel inlet 14c ', and a fourth fuel inlet 14d' in the order of fuel flow.

Specifically, the head portion of the rotary groove communicates with both the first fuel inlet 14a ' and the fuel supply passage 3', and the tail portion communicates with the fourth fuel inlet 14d '. The centre line of the fuel feed channel 3' is curved and a section close to the rotating slot is tangential to the outer wall of the jet chamber 9. Therefore, a rotary feeding mode is formed together, the air inlet rotational flow of the mixed air is improved, and the mixing of the fuel in the jet flow chamber is facilitated.

The pore size of the plurality of fuel inlets increases as the distance fuel travels within the groove 15 increases.

Specifically, the diameter of the first fuel inlet 14a 'is less than the diameter of the second fuel inlet 14b' is less than the diameter of the third fuel inlet 14c 'is less than the diameter of the fourth fuel inlet 14d'.

The invention fully utilizes the existing structure of the existing spark ignition engine, reduces the change requirement on the engine cylinder cover and the cost requirement on the research and development of a novel jet ignition engine by laterally arranging the oil injector, and is easy to realize. The invention can generate more homogeneous premixed combustible mixed gas in the jet chamber, is beneficial to generating more homogeneous jet flame, and reduces the problems of combustion instability such as additional detonation and the like caused by uneven jet.

The fuel injector can adopt single gas fuel, liquid fuel or liquid fuel with auxiliary gas.

When single fuel is adopted, the fuel injector adopts a two-time or multi-time injection strategy; the first injection of the fuel injector is formed in the air intake, and the injection time is 270-180 degrees before the ignition top dead center; the second injection of the fuel injector occurs in the compression stroke, and the injection triggering time is in the range from 180 degrees to 90 degrees before the ignition top dead center;

the spark plug is matched with a multi-injection strategy of the oil injector to carry out multi-ignition; the control system controls the spark plug to trigger one-time or multi-time ignition after the first injection, and because the mixed gas in the jet flow chamber is thin, effective jet flow cannot be produced, and a large amount of active free radicals are generated in the jet flow chamber by discharging, so that the activation of the mixed gas atmosphere and the subsequent rapid combustion are facilitated;

after the fuel injector performs the second injection, the control system controls the spark plug to perform one or more times of ignition, at the moment, the mixed gas inside the jet flow chamber is in an ideal state, effective combustion is generated, a large amount of heat is released, and the jet flow chamber generates homogeneous jet flow.

When gas-assisted liquid fuel is used, the fuel injector performs four or more injections; the first injection of the fuel injector is carried out in an air inlet stroke, auxiliary gas is injected, the injection time is 360-270 degrees before the ignition top dead center, and the injected auxiliary gas is helpful for driving residual waste gas in a fuel supply channel, a groove and a jet flow chamber;

the second injection of the fuel injector occurs in an intake stroke, liquid fuel is injected, and the injection triggering time is in the range of 270-180 degrees before the ignition top dead center;

the third injection of the fuel injector is carried out in the compression stroke, liquid fuel is injected, and the injection triggering time is in the range of 180-90 degrees before the ignition top dead center;

the fourth injection of the fuel injector is carried out in the compression stroke, auxiliary gas is injected, the injection triggering time is in the range of 180-90 degrees before the ignition top dead center, and the auxiliary gas injected at this time is helpful for driving liquid fuel remained in the fuel supply channel and the groove;

the spark plug is matched with a multi-injection strategy of the oil injector to carry out multi-ignition; the control system controls the spark plug to trigger one-time or multi-time ignition after the second injection, and because the mixed gas in the jet flow chamber is thin, effective jet flow cannot be produced, and a large amount of active free radicals are generated in the jet flow chamber by discharging, so that the activation of the mixed gas atmosphere and the subsequent rapid combustion are facilitated; after the oil sprayer sprays for the third time, the control system controls the spark plug to ignite for one time or multiple times, at the moment, the mixed gas inside the jet flow chamber is in an ideal state, effective combustion is generated, a large amount of heat is released, and homogeneous jet flow is generated in the jet flow chamber.

The fuel supply passage, i.e. the elongate bore initially described, has been described, but to this end the invention also provides a fuel supply passage for use in a side-jet ignition system if direct drilling presents certain technical difficulties.

The invention designs a fuel supply channel applied to a side jet ignition system, which is characterized in that: comprises a cylinder cover, a nozzle and a jet chamber installation body; the nozzle is arranged on the side wall of the cylinder cover, and the jet flow chamber mounting body is arranged on the cylinder cover and is coaxial with the cylinder; the jet chamber installation body is provided with a jet chamber, and the jet chamber is provided with a plurality of jet holes; a fuel supply channel is arranged on the cylinder cover; one end of the fuel supply channel is communicated with the nozzle, and the other end of the fuel supply channel is communicated with the jet flow chamber;

the fuel supply passage includes: a cylinder cover bottom hole and a fine hole which are positioned on the cylinder cover;

one end of the bottom hole of the cylinder cover is communicated with a nozzle inserted into the cylinder cover, the other end of the bottom hole of the cylinder cover is communicated with one end of the fine hole, and the other end of the fine hole is communicated with the jet flow chamber;

a detachable fuel pipe body is arranged in the bottom hole of the cylinder cover; the fuel pipe body is provided with a coaxial fuel through hole, and the fuel through hole is communicated with the fine hole.

Preferably, a plurality of fuel oil pipe bodies which are connected end to end and are used for communicating the nozzle with the fine hole are arranged in the bottom hole of the cylinder cover.

Further preferably, the outer contour of the head end of the fuel oil pipe body is a rotating surface with the axis thereof as a rotating shaft, and the outer contour of the tail end is in adaptive connection with the head end.

Further preferably, the head end and the tail end of the fuel oil pipe are in adaptive sealing connection by adopting spherical, conical and cylindrical profile surfaces.

Preferably, the diameter of the cylinder head bottom hole is larger than that of the fine hole.

Preferably, the pore diameter of the fine pores is 0.5mm to 1.0mm.

Preferably, the outer diameter of the fuel pipe body is equal to that of a bottom hole of the cylinder cover, and the diameter of the fuel through hole is equal to that of the fine hole.

Optionally, a plurality of air passage openings for exhaust and/or intake are provided in the cylinder head, and the fuel supply passage is located in the cylinder head between the two air passage openings.

The invention fully utilizes the manufacturing and assembling process of the existing engine parts, and realizes the requirement that the side jet ignition system supplies fuel through the slender inner hole of the cylinder cover on the premise of lower manufacturing and assembling cost, so that the mass production and sale of the engine products of the side jet ignition system become possible. The method of positioning by scribing effectively solves the problem that the centering hole on the jet chamber installation body is difficult to position and process, effectively ensures the assembly quality, and solves the practical difficult problems of processing and cleaning after assembly.

As shown in fig. 3, 8 and 9, the fuel supply passage designed by the invention and applied to the side jet ignition system comprises a cylinder head 1, a nozzle 2 and a jet chamber installation body 4; the nozzle 2 is arranged on the side wall of the cylinder cover 1, and the jet flow chamber installation body 4 is arranged on the cylinder cover 1 and is coaxial with the cylinder; the jet chamber installation body 4 is provided with a jet chamber, and the jet chamber is provided with a plurality of jet holes; a fuel supply channel is arranged on the cylinder cover 1; one end of the fuel supply channel is communicated with the nozzle 2, and the other end of the fuel supply channel is communicated with the jet flow chamber;

the fuel supply passage includes: a cylinder cover bottom hole 1.1 and a fine hole 1.2 which are positioned on the cylinder cover 1; one end of the cylinder cover bottom hole 1.1 is communicated with a nozzle 2 inserted into the cylinder cover 1, the other end of the cylinder cover bottom hole is communicated with one end of the fine hole 1.2, and the other end of the fine hole 1.2 is communicated with the jet flow chamber;

a detachable fuel pipe body 16 is arranged in the cylinder cover bottom hole 1.1; the fuel pipe body 16 is provided with a coaxial fuel through hole 16.1, and the fuel through hole 16.1 is communicated with the fine hole 1.2.

Preferably, a plurality of fuel pipe bodies 16 which are connected end to end and are used for communicating the nozzle 2 with the fine holes 1.2 are arranged in the cylinder cover bottom hole 1.1. The outline of the head end of the fuel pipe body 16 is a rotating surface taking the axis thereof as a rotating shaft, and the outline of the tail end is in adaptive connection with the head end. The head end and the tail end of the fuel pipe 16 are in adaptive sealing connection with spherical, conical and cylindrical profile surfaces.

Preferably, the diameter of the cylinder head bottom hole 1.1 is larger than that of the fine hole 1.2.

Preferably, the pore diameter of the fine pores 1.2 is 0.5mm to 1.0mm.

Preferably, the outer diameter of the fuel pipe body 16 is equal to that of the cylinder head bottom hole 1.1, and the diameter of the fuel through hole 16.1 is equal to that of the fine hole 1.2.

The cylinder cover 1 is provided with a plurality of air passage openings 5 for exhausting and/or intaking air, and the fuel supply passage is positioned on the cylinder cover 1 between the two air passage openings 5.

Preferably, the fuel supply channel applied to the side jet ignition system designed by the invention further comprises a nozzle mounting body 7 fixed with the cylinder cover 1, and the nozzle 2 is mounted on the nozzle mounting body 7 through a nozzle mounting pressing plate 6.

The total length of the fuel pipe body 16 is controlled within the range convenient for processing the pore 1.2, and the fuel pipe bodies 16 combined by a plurality of sections are sequentially arranged in the cylinder cover bottom hole 1.1. The head of the fuel pipe body 16 is of a spherical structure, so that the multi-section combination installation and sealing are convenient. The nozzle 2 is installed on the side surface of the cylinder cover 1, and the nozzle 2 and the plurality of fuel pipe bodies 16 are installed in a pressing mode through the nozzle installation pressing plate 6. The fuel enters from the nozzle feed inlet, passes through the nozzle 2, the plurality of fuel pipe bodies 16 and the fine holes 1.2 and then is delivered into the jet flow chamber for subsequent related ignition combustion work.

The jet chamber installation body 4 is installed on the cylinder cover 1 through threads, in order to ensure that the fine hole 1.2 and the installation hole on the jet chamber installation body 4 are screwed more than once before the fuel inlet, namely the feeding hole on the jet chamber installation body 4 is machined, the position of the installation hole on the installation body and the cylinder cover is carved on the parts of the jet chamber installation body 4 after the jet chamber installation body is screwed according to the position size of the fuel feeding hole on the cylinder cover, the installation hole is machined according to the carved line after the installation body is loosened, and the installation body is screwed according to the same installation and assembly process after the hole machining is finished.

The invention provides a fuel supply channel applied to a side jet ignition system, wherein a fuel pipe body is generally divided into a plurality of sections according to requirements, the pipe bodies with the same length can be selected, and different length combinations can be selected according to actual lengths. The two ends of the fuel pipe body are adaptive connection structures, generally spherical, conical and cylindrical rotating body structures which are convenient for connection and sealing. The final determined length of the fuel pipe body 16 is related to the diameter of the fuel through hole 16.1 and the actual processing length, and can be reasonably selected according to different processing equipment, process level and cost requirements. The length dimension of the pores 1.2 needs to take into account the processing equipment capacity, the processing cost and the total volume design requirement of the fuel channel in order to achieve the simultaneous consideration of the manufacturing cost and the jet transient performance.

The specific implementation flow of the invention is as follows: firstly, designing and arranging a general scheme according to the requirements of a side-mounted jet type ignition system, determining the specific position of a fine hole 1.2 on a cylinder cover 1, calculating the total length and diameter of the fine hole 1.2, determining the length and the number of nodes of a single-node fuel pipe body, designing the machining size of a cylinder cover bottom hole 1.1, and designing the specific structures of the fuel pipe body 16, a nozzle mounting body 7 and a nozzle mounting pressure plate 6. After the overall arrangement and design work is finished, parts such as a cylinder cover bottom hole, a fuel pipe body, a jet flow chamber installation body, a nozzle installation pressing plate and the like are processed according to the drawing requirements.

The hole connected with the fine hole on the jet chamber installation body, namely the fuel inlet, is not required to be processed in the first part processing and manufacturing process, the jet chamber installation body is assembled on the cylinder cover according to the installation requirement, the cylinder cover and the jet chamber installation body are scribed, and then the jet chamber installation body is loosened and removed, and the connection through hole is processed according to the scribed position. And after the machining is finished, restoring and installing the jet chamber installation body according to the assembly requirement. The installation sequence and the installation positions of all the combined pipe bodies are installed in the bottom hole of the cylinder cover, the nozzle installation body is installed on the cylinder cover according to requirements, the nozzle is inserted into the nozzle installation body and the bottom hole of the cylinder cover, and the nozzle and each section of combined pipe body are pressed tightly by the nozzle pressing plate, so that the sealing requirements among all the parts are met.

The path and manner of fuel entering the cylinder head, and the path and manner of fuel entering the intake plenum are described above; how the fuel in the jet chamber enters the main chamber, and the design of the main chamber, are described below.

The invention relates to a jet flow-compression ignition combustion system of a multi-partition combustion chamber, which is characterized in that:

comprises a cylinder cover, a nozzle, a jet chamber and a spark plug; a fuel supply channel is arranged on the cylinder cover; the nozzle is arranged on the side wall of the cylinder cover; the jet chamber is arranged on the cylinder cover and is coaxial with the cylinder; the spark plug is communicated with the jet flow chamber and is positioned right above the jet flow chamber; the jet chamber is provided with a plurality of jet holes; one end of the fuel supply channel is communicated with the nozzle, and the other end of the fuel supply channel is communicated with the jet chamber through one or more fuel inlets arranged on the jet chamber; the cylinder cover is connected with a cylinder sleeve, and a piston is arranged in the cylinder sleeve;

Preferably, the concave pits are spherical caps.

Preferably, the depth of the pits is 15mm to 50mm.

Further preferably, the aperture of the first jet hole is 1 mm-2 mm.

Further preferably, 4-8 first jet holes are arranged.

Further preferably, the aperture of the second jet hole is 0.5 mm-1 mm.

Further preferably, the diameter of the fuel inlet is 0.5mm to 1.5mm.

Still more preferably, the diameter of the groove is 0.5mm to 2.0mm.

The invention reduces the possibility of detonation induced by spontaneous combustion of the tail end gas mixture, and is beneficial to improving the structural stability, the anti-detonation performance and the reliability of the engine. The cylinder wall-oriented induced jet flow is beneficial to eliminating sources of unburned hydrocarbon at the tail end and reducing the emission of hydrocarbon, and meanwhile, the compression ignition is introduced into the combustion system, so that the combustion rate and the isochoricity under lean combustion are improved, and the thermal efficiency is improved.

As shown in FIG. 10, the jet flow-compression ignition combustion system of the double swirl combustion chamber designed by the invention comprises a cylinder head 1, a nozzle 2, a jet flow chamber 9 and a spark plug 10; a fuel supply channel 3' is arranged on the cylinder head 1; the nozzle 2 is arranged on the side wall of the cylinder cover; the jet chamber 9 is arranged on the cylinder cover 1 and is coaxial with the cylinder; the spark plug 10 is communicated with the jet flow chamber 9 and is positioned right above the jet flow chamber 9; the jet chamber 9 is provided with a plurality of jet holes; one end of the fuel supply channel 3' is communicated with the nozzle 2, and the other end is communicated with the jet chamber 9 through one or more fuel inlets arranged on the jet chamber 9; the cylinder cover 1 is connected with a cylinder sleeve 8, and a piston 12 is arranged in the cylinder sleeve 8;

the spark plug 10 and the jet flow chamber 9 are designed in an integrated mode, the spark plug 10 is located in the middle of the jet flow chamber 9, and the jet flow chamber 9 is installed in the middle of the cylinder cover 1, so that the distance between the first jet flow spray hole 17 and the wall of an engine cylinder is consistent;

the top of the piston 12 is provided with a concave pit 21 and a concave ring groove 18; the center of the pit 21 is over against the axis of the jet flow chamber; the groove 18 is located outside the recess 21 and coaxial therewith.

The jet flow generated by the jet flow chamber is matched with the shape of the piston, the center of the piston 12 is a spherical pit, namely a spherical crown-shaped pit 21, the maximum diameter of the pit 21 is 30-50% of the diameter of the piston, the periphery of the pit 21 is a concave ring groove 18, the diameter of the concave ring groove 18 is about 50-90% of the diameter of the piston, the inner side wall surface of the concave ring groove 18 is tangent to the jet flow 19 in the direction of the top dead center position of the engine, the jet flow 19 is induced by the inner side wall of the concave ring groove 18, and rolls upwards after being transited by the arc part at the bottom of the concave ring groove 18, and a continuous rolling flow area is induced in the near-wall area of the cylinder. The induction of the pocket groove 18 provides more efficient combustion of the jet and eliminates the end mixture near the wall, reducing the tendency of the end to auto-ignite inducing intense detonation.

The depth of the pit is 15 mm-50 mm, the center of the pit is just opposite to the bottom center spray hole of the jet chamber, namely the second jet hole 20, and the jet flame can be more effectively quenched due to the smaller diameter of the second jet hole 20, so that the jet flow contains high-activity free radicals. During the compression stroke, tumble and squish flow areas are formed in the pit areas, and after the spark plug is ignited, the active free radicals contained in the central jet flow activate the mixed gas in the central pit area, so that the whole pit area forms an ignition mode of spontaneous combustion.

The high edge at the junction of the concave pit 21 and the concave ring groove 18 effectively divides the combustion chamber into two areas in ignition combustion: one is a peripheral groove area, takes jet flame propagation as a characteristic, effectively eliminates tail end mixed gas by high-energy jet ignition, reduces the possibility of strong detonation caused by spontaneous combustion of tail end gas, and simultaneously reduces the emission source of near-wall hydrocarbon; the other is a spontaneous combustion area at the center of the pit, and the activity-induced central spontaneous combustion is beneficial to improving the combustion speed in the cylinder, accelerating the combustion, improving the combustion isocapacity and improving the heat efficiency.

The whole combustion system is of a centrosymmetric structure, the volume of the jet chamber 9 is about 1-3% of that of the main combustion chamber, a plurality of first jet holes 17 which are uniformly distributed are axially arranged at the bottom of the jet chamber 9, the number of the first jet holes is 4-8, the aperture is 1-2 mm, and the included angle between the injection direction of the first jet holes 17 and the vertical central line, namely the axis of the jet chamber 9, is 45-75 degrees; the middle of the bottom of the jet chamber 9 is provided with a second jet hole 20, and the aperture of the second jet hole 20 is 0.5 mm-1 mm.

The above-described multi-zone combustion chamber jet-compression ignition combustion system may also be combined with the split side-mounted jet ignition system wherein the fuel enters the jet chamber

As shown in fig. 6 and 7, when a plurality of fuel inlets 14 are provided, two embodiments employ four fuel inlets, and the fuel supply passage 3' is connected to the fuel inlets 14 via the grooves 15; the groove center line, the axis of the fuel supply channel and the axes of the plurality of fuel inlets are coplanar; the diameter of the fuel inlet is 0.5 mm-1.5 mm.

As shown in fig. 6, with the annular groove, the fuel supply passage 3 'is a straight hole and the center line of the fuel supply passage 3' passes through the center of the annular groove. The fuel inlets 14 are uniformly distributed, and the axes of the fuel inlets perpendicularly intersect with the axis of the jet flow chamber 9.

As shown in fig. 7, the groove 15 is a rotary groove; one end of the rotary groove is communicated with the first fuel inlet and the fuel supply channel 3' at the same time, and the other end is communicated with the last fuel inlet. In this example, four fuel inlets are provided, one for each of the first fuel inlet 14a ', the second fuel inlet 14b', the third fuel inlet 14c ', and the fourth fuel inlet 14d' in the order of fuel flow.

Specifically, the head portion of the rotary groove communicates with both the first fuel inlet 14a ' and the fuel supply passage 3', and the tail portion communicates with the fourth fuel inlet 14d '. The centre line of the fuel supply channel 3' is curved and a section close to the rotary slot is tangential to the outer wall of the jet chamber 9. Therefore, a rotary feeding mode is formed together, the air inlet cyclone degree of the mixed air is improved, and the mixing of the fuel in the jet flow chamber is facilitated.

The embodiments of the present invention have been presented for purposes of illustration and description, and are not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to practitioners skilled in this art. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A jet-compression ignition combustion system of a multi-partition combustion chamber is characterized in that:

comprises a cylinder cover, a nozzle, a jet chamber and a spark plug; a fuel supply channel is arranged on the cylinder cover; the nozzle is arranged on the side wall of the cylinder cover; the jet chamber is arranged on the cylinder cover and is coaxial with the cylinder; the spark plug is communicated with the jet flow chamber and is positioned right above the jet flow chamber; the jet chamber is provided with a plurality of jet holes; one end of the fuel supply channel is communicated with the nozzle, and the other end of the fuel supply channel is communicated with the jet chamber through a plurality of fuel inlets arranged on the jet chamber; the cylinder cover is connected with a cylinder sleeve, and a piston is arranged in the cylinder sleeve; the top of the piston is provided with a pit and a concave ring groove; the center of the pit is over against the axis of the jet flow chamber; the concave ring groove is positioned on the outer side of the concave pit and is coaxial with the concave pit;

the fuel supply passage communicates with the jet chamber through a plurality of fuel inlets; a groove is arranged on the cylinder cover which is contacted with the plurality of fuel inlets; the fuel supply channel is communicated with the plurality of fuel inlets through the groove; the pore size of the plurality of fuel inlets increases as the distance fuel travels within the groove increases.

2. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 1, wherein: the concave pits are spherical crowns; the maximum diameter of the concave pit is 30% -50% of the diameter of the piston.

3. The jet-compression ignition combustion system of a multi-zone combustion chamber of claim 1 or 2, characterized in that: the depth of the concave pit is 15 mm-50 mm.

4. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 1, wherein: the maximum diameter of the concave ring groove is 50% -90% of the diameter of the piston.

5. The jet-compression ignition combustion system of a multi-zone combustion chamber of claim 1 or 4, characterized in that: the inner side wall surface of the concave ring groove is tangent to the jet flow stream direction at the top dead center position of the engine.

6. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 1, wherein: the volume of the jet flow chamber is 1-3% of the volume of the main combustion chamber.

7. The jet-compression ignition combustion system of a multi-zone combustion chamber of claim 1 or 6, characterized in that: the bottom of the jet flow chamber is axially provided with a plurality of uniformly distributed first jet flow holes, and the included angle between the jet direction of the first jet flow holes and the axis of the jet flow chamber is 45-75 degrees.

8. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 7, wherein: the aperture of the first jet hole is 1 mm-2 mm.

9. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 7, wherein: 4-8 first jet holes are arranged.

10. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 7, wherein: and a coaxial second jet hole is arranged in the middle of the bottom of the jet chamber, and the jet direction of the second jet hole is coaxial with the axis of the jet chamber.

11. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 10, wherein: the aperture of the second jet hole is 0.5 mm-1 mm.

12. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 1, wherein: the diameter of the fuel inlet is 0.5 mm-1.5 mm.

13. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 1, wherein: the groove centerline, the axis of the fuel feed passage, and the axes of the plurality of fuel inlets are coplanar.

14. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 1, wherein: the diameter of the groove is 0.5 mm-2.0 mm.

15. The jet-compression ignition combustion system for a multi-zone combustion chamber as claimed in any one of claims 10 to 14, wherein: the groove is an annular groove, the fuel supply channel is a straight hole, and the center line of the fuel supply channel passes through the circle center of the annular groove.

16. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 15, wherein: the fuel inlets are uniformly distributed, and the axes of the fuel inlets are vertically intersected with the axis of the jet flow chamber.

17. The jet-compression ignition combustion system for a multi-zone combustion chamber as claimed in any one of claims 10 to 14, wherein: the groove is a rotary groove; one end of the rotary groove is communicated with the first fuel inlet and the fuel supply channel at the same time, and the other end of the rotary groove is communicated with the last fuel inlet.

18. The jet-compression ignition combustion system for a multi-zone combustion chamber of claim 17, wherein: the central line of the fuel supply channel is an arc line, and a section close to the rotating groove is tangent to the outer wall of the jet flow chamber.