CN115773177A - Jet ignition combustion system and jet control method for hydrogen internal combustion engine - Google Patents

Abstract

The application relates to a jet ignition combustion system and an injection control method of a hydrogen internal combustion engine, comprising the following steps: the hydrogen internal combustion engine comprises a cylinder body and a piston which is connected in the cylinder body in a sliding manner, wherein a cylinder cover is arranged at the top of the cylinder body, and a main combustion chamber is formed among the cylinder body, the cylinder cover and the piston; the main ejector is fixed on the cylinder cover and extends into the main combustion chamber, and the main ejector is used for ejecting hydrogen into the main combustion chamber at the initial stage and the final stage of the compression stroke respectively; the pre-combustion chamber is fixedly connected with the cylinder cover and is positioned on the central axis of the piston, a plurality of jet holes communicated with the main combustion chamber are formed in the pre-combustion chamber, and the piston presses the mixed gas in the main combustion chamber into the pre-combustion chamber through the jet holes in a compression stroke; and the spark plug is fixedly connected with the pre-combustion chamber and extends into the pre-combustion chamber, and the spark plug is used for igniting the mixed gas in the pre-combustion chamber when the piston reaches the vicinity of the top dead center so as to generate homogeneous jet flow to ignite the main combustion chamber. This application can make whole combustion chamber produce super clean, effectual combustion effect.

Description

Jet ignition combustion system and jet control method for hydrogen internal combustion engine

Technical Field

The application relates to the technical field of hydrogen internal combustion engines, in particular to a jet ignition combustion system of a hydrogen internal combustion engine and an injection control method.

Background

Most common engine systems use fossil fuels, and the large emission of CO2, a combustion product, poses a serious environmental problem, and carbon dioxide is considered to be a major source for exacerbating the greenhouse effect. However, the idea of improving engine emissions by replacing gasoline and diesel with carbonaceous fuels such as natural gas, alcohols, and liquefied petroleum gas seems to be only a mitigation rather than a radical treatment for environmental pollution.

Hydrogen is a well-known "clean" energy carrier, which has the greatest advantage of being carbon-free and not producing emissions of carbon-containing pollutants. In addition, the hydrogen has the characteristics of cleanness, continuous regeneration and the like, has good combustion performance when being used for an automobile engine, and is expected to become an excellent fuel for replacing the traditional fossil fuel as an internal combustion engine for the automobile. However, unlike liquid fuels, how to accept the existing engine technologies and develop hydrogen internal combustion engines based on these technologies is a problem that needs to be solved to ensure/even improve the engine performance and to realize stable operation of hydrogen internal combustion engines.

In the related art, hydrogen supply modes of a hydrogen internal combustion engine are mainly divided into gas inlet channel hydrogen injection and in-cylinder direct hydrogen injection, and for the gas inlet channel hydrogen injection internal combustion engine, the hydrogen occupies a part of the working volume of a cylinder, so that the charge coefficient is small, the output power is low, and abnormal combustion phenomena such as pre-ignition, backfire and detonation are possibly induced.

The direct-injection hydrogen internal combustion engine in the cylinder avoids hydrogen from occupying the working volume of the cylinder, improves the charge coefficient, and can inhibit abnormal combustion, but the problem of how to reasonably design the whole system of the direct-injection hydrogen internal combustion engine in the cylinder is the current problem. In addition, the high performance and low emission of the direct hydrogen injection internal combustion engine are related to the formation and combustion mode of the hydrogen-air mixture, and the proposal of a reasonable hydrogen injection strategy and a combustion control method of the direct hydrogen injection internal combustion engine are also important.

Disclosure of Invention

The embodiment of the application provides a jet ignition combustion system and a jet control method of a hydrogen internal combustion engine, and aims to solve the problems that how to reasonably design the whole system of a direct-injection hydrogen internal combustion engine in a cylinder in the related technology, and the mixture of hydrogen and air is ignited and combusted under the high-compression condition, so that the combustion process is efficient and stable.

In a first aspect, an embodiment of the present application provides a jet ignition combustion system for a hydrogen internal combustion engine, including:

the hydrogen internal combustion engine comprises a cylinder body and a piston which is connected in the cylinder body in a sliding manner, wherein a cylinder cover is arranged at the top of the cylinder body, and a main combustion chamber is formed among the cylinder body, the cylinder cover and the piston;

the main injectors are fixed on the cylinder cover and extend into the main combustion chamber, and are used for injecting hydrogen into the main combustion chamber in the initial stage and the final stage of a compression stroke respectively;

the pre-combustion chamber is fixedly connected with the cylinder cover and is positioned on the central axis of the piston, a plurality of jet holes communicated with the main combustion chamber are formed in the pre-combustion chamber, and the piston presses mixed gas in the main combustion chamber into the pre-combustion chamber through the jet holes in a compression stroke;

the spark plug is fixedly connected with the pre-combustion chamber and extends into the pre-combustion chamber, and the spark plug is used for igniting the mixed gas in the pre-combustion chamber when the piston reaches the vicinity of the top dead center so as to generate homogeneous jet flow to ignite the main combustion chamber.

In some embodiments: the pre-combustion chamber comprises a spark plug connecting section and a jet flow cavity shell connected with the spark plug connecting section, and the spark plug connecting section is provided with a threaded hole which is used for connecting a spark plug and communicated with the jet flow cavity shell;

the jet cavity shell is of a spherical crown structure protruding towards the direction of the main combustion chamber, the plurality of jet holes are formed in the jet cavity shell, and one end, close to the jet cavity shell, of each threaded hole is provided with a conical slope surface with the diameter gradually increasing.

In some embodiments: the jet holes comprise an upper layer jet hole and a lower layer jet hole which are positioned on the jet cavity shell, the lower layer jet holes are uniformly distributed around the circumference of the axial direction of the pre-combustion chamber, and the angle between the opening direction of the lower layer jet hole and the axial line of the pre-combustion chamber is 45-75 degrees;

the aperture of the upper-layer jet hole is larger than that of the lower-layer jet hole, the upper-layer jet hole is positioned on one side close to the conical slope surface, and the hole opening direction of the upper-layer jet hole is parallel to the conical slope surface.

In some embodiments: the ratio of the volume of the precombustion chamber to the volume of the main combustion chamber is 2%, the number of the upper-layer jet holes is 3-5, and the number of the lower-layer jet holes is 6-8.

In some embodiments: the top surface of the piston is provided with a ball socket with an upward opening, when the piston reaches the vicinity of a top dead center, a pre-combustion chamber positioned in the main combustion chamber is at least partially positioned in the ball socket, and the compression ratio of the main combustion chamber is 15-18.

In some embodiments: the outlet of the main ejector is provided with an ejection cap, the ejection cap is provided with a plurality of ejection holes, the diameter of each ejection hole is larger than 1.5mm, and the ejection directions are obtained by respectively connecting a plurality of points which are uniformly distributed on the top plane of the piston and the circle of the lower surface plane of the ejection cap.

In some embodiments: the pre-combustion chamber is characterized by further comprising an auxiliary injector fixedly connected with the cylinder cover and extending into the pre-combustion chamber, wherein the auxiliary injector is used for injecting hydrogen into the pre-combustion chamber at the end of a compression stroke.

In some embodiments: the cylinder cover is also provided with an air inlet channel and an air outlet channel which are communicated with the main combustion chamber, the air inlet channel is provided with an air inlet valve for opening and closing the air inlet channel, and the air outlet channel is provided with an exhaust valve for opening and closing the air outlet channel.

A second aspect of the embodiments of the present application provides an injection control method for a jet ignition combustion system of a hydrogen internal combustion engine, which uses the jet ignition combustion system of the hydrogen internal combustion engine described in any one of the embodiments above, the method including the steps of:

the main injector injects hydrogen for the first time to the main combustion chamber according to the engine speed within the range of 138-118 degrees before the top dead center, and the hydrogen and fresh air form mixed gas outside the pre-combustion chamber;

along with the upward movement of the piston, the mixed gas in the main combustion chamber is pressed into the pre-combustion chamber through a plurality of jet holes, and under the flow guiding action of the conical slope surface in the pre-combustion chamber, tumble flow is formed in the pre-combustion chamber to sweep the waste gas in the pre-combustion chamber;

before the air inlet valve is closed and the pressure of the main combustion chamber rises to 12.5bar, the main injector injects hydrogen to the main combustion chamber for the second time so as to meet the power output of the engine;

when the piston reaches the top dead center, the controller controls the spark plug to carry out one or more times of ignition, and at the moment, the mixed gas in the precombustion chamber is ignited, so that the pressure in the precombustion chamber is increased, and the pressure difference is established between the precombustion chamber and the main combustion chamber;

the mixed gas is combusted in the pre-combustion chamber to release heat, and due to the existence of pressure difference, the pre-combustion chamber generates homogeneous jet flow which is jetted to the main combustion chamber, and the flame in the jet flow further ignites or activates the mixed gas in the main combustion chamber.

A third aspect of the embodiments of the present application provides an injection control method for a jet ignition combustion system of a hydrogen internal combustion engine, which uses the jet ignition combustion system of the hydrogen internal combustion engine according to any one of the embodiments described above, the method including the steps of:

after the air inlet valve is closed, the main injector starts to inject hydrogen into the main combustion chamber, and the hydrogen and fresh air form mixed gas outside the pre-combustion chamber;

in the ascending process of the piston, the mixed gas in the main combustion chamber is pressed into the precombustion chamber through a plurality of jet holes;

the auxiliary injector injects hydrogen into the pre-combustion chamber at the last stage of the compression stroke so as to enhance the concentration of mixed gas in the pre-combustion chamber and balance the pressure difference between the inside and the outside of the pre-combustion chamber;

when the piston reaches the top dead center, the controller controls the spark plug to carry out one or more times of ignition, and at the moment, the mixed gas in the precombustion chamber is ignited, so that the pressure in the precombustion chamber is increased, and the pressure difference is established between the precombustion chamber and the main combustion chamber;

the mixed gas is combusted in the pre-combustion chamber to release heat, and due to the existence of pressure difference, the pre-combustion chamber generates homogeneous jet flow which is jetted to the main combustion chamber, and the flame in the jet flow further ignites or activates the mixed gas in the main combustion chamber.

The beneficial effect that technical scheme that this application provided brought includes:

the embodiment of the application provides a jet ignition combustion system and a jet control method of a hydrogen internal combustion engine, and the jet ignition combustion system of the hydrogen internal combustion engine is provided with the hydrogen internal combustion engine, wherein the hydrogen internal combustion engine comprises a cylinder body and a piston which is connected in the cylinder body in a sliding manner, the top of the cylinder body is provided with a cylinder cover, and a main combustion chamber is formed among the cylinder body, the cylinder cover and the piston; the main ejector is fixed on the cylinder cover and extends into the main combustion chamber, and the main ejector is used for ejecting hydrogen into the main combustion chamber at the initial stage and the final stage of the compression stroke respectively; the pre-combustion chamber is fixedly connected with the cylinder cover and is positioned on the central axis of the piston, a plurality of jet holes communicated with the main combustion chamber are formed in the pre-combustion chamber, and the piston presses mixed gas in the main combustion chamber into the pre-combustion chamber through the jet holes in a compression stroke; and the spark plug is fixedly connected with the pre-combustion chamber and extends into the pre-combustion chamber, and the spark plug is used for igniting the mixed gas in the pre-combustion chamber when the piston reaches the vicinity of the top dead center so as to generate homogeneous jet flow to ignite the main combustion chamber.

Therefore, the jet ignition combustion system of the hydrogen internal combustion engine can be divided into an active jet ignition combustion system and a passive jet ignition combustion system. The spark plug of the precombustion chamber allows decoupling the precombustion chamber and the main combustion chamber, and improves the dilution limit of the mixture. The high dilution of the mixture reduces the risk of pre-ignition, knock, and increases power, torque, and BTE. The hydrogen and air mixture is ignited and combusted under high compression conditions, making the combustion process efficient and stable. The gas plasma generated by the precombustion chamber enters the main combustion chamber through the plurality of jet holes, and the gas mixture in the main combustion chamber can be quickly and uniformly ignited due to high energy content. The combustion chamber can generate ultra-clean and effective combustion effect in the whole combustion chamber, and almost or not generate pollutants such as nitrogen oxides and the like.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a jet ignition combustion system of a passive jet type hydrogen internal combustion engine according to an embodiment of the present application;

FIG. 2 is a schematic structural view of a pre-combustion chamber and spark plug according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a jet ignition combustion system of an active jet type hydrogen internal combustion engine according to an embodiment of the present application.

Reference numerals:

1. a cylinder cover; 2. a main injector; 3. a piston; 4. a cylinder body; 5. a spark plug; 6. a pre-combustion chamber; 7. a secondary ejector; 8. a tapered slope; 9. a lower jet hole; 10. and an upper layer jet hole.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making creative efforts shall fall within the protection scope of the present application.

The embodiment of the application provides a jet ignition combustion system and a jet control method of a hydrogen internal combustion engine, which can solve the problems that how to reasonably design the whole system of a direct injection hydrogen internal combustion engine in a cylinder in the related technology, and the mixture of hydrogen and air is ignited and combusted under the high-compression condition, so that the combustion process is efficient and stable.

Referring to fig. 1 and 2, in a first aspect, an embodiment of the present application provides a jet ignition combustion system for a hydrogen internal combustion engine, including:

the hydrogen internal combustion engine comprises a cylinder body 4 and a piston 3 which is connected in the cylinder body 4 in a sliding mode, a cylinder cover 1 for closing the cylinder body 4 is arranged on the top of the cylinder body 4, and a main combustion chamber is formed among the cylinder body 4, the cylinder cover 1 and the piston 3.

And the main ejector 2 is fixed on the cylinder head 1 and extends into the main combustion chamber, and the main ejector 2 is used for ejecting hydrogen with set flow into the main combustion chamber according to the engine speed at the end of an intake stroke and a compression stroke respectively.

The pre-combustion chamber 6 is fixedly connected with the cylinder cover 1 and is positioned on the central axis of the piston 3, a plurality of jet holes communicated with the main combustion chamber are formed in the pre-combustion chamber 6, and the piston 3 presses mixed gas in the main combustion chamber into the pre-combustion chamber 6 through the jet holes in the compression stroke stage.

And the spark plug 5 is fixedly connected with the pre-combustion chamber 6 and extends into the pre-combustion chamber 6, and the spark plug 5 is used for igniting the mixture in the pre-combustion chamber 6 when the piston 3 reaches the position near the top dead center so as to generate a homogeneous jet flow to ignite the mixture in the main combustion chamber.

The embodiment of the application is provided with the precombustion chamber 6 on the cylinder cover 1, and the spark plug of the precombustion chamber 6 allows decoupling of the precombustion chamber 6 and the main combustion chamber, so that the dilution limit value of the mixed gas is improved. The high dilution of the air-fuel mixture reduces the risk of engine pre-ignition, knock, and increases power, torque, and BTE.

The main injector 2 injects hydrogen with set flow into the main combustion chamber at the initial stage and the final stage of the compression stroke, the hydrogen and fresh gas are mixed in the main combustion chamber to form mixed gas, and the piston 3 presses the mixed gas in the main combustion chamber into the pre-combustion chamber 6 through jet holes at the stage of the compression stroke, so that a passive jet type jet ignition combustion system of the hydrogen internal combustion engine is formed.

The spark plug 5 ignites and combusts the hydrogen and air mixture under high compression conditions, making the combustion process efficient and stable. The gas plasma generated by the pre-combustion chamber 6 enters the main combustion chamber through a plurality of jet holes, and the gas mixture in the main combustion chamber can be quickly and uniformly ignited due to high energy content.

In some alternative embodiments: referring to fig. 2, the embodiment of the present application provides a jet ignition combustion system of a hydrogen internal combustion engine, wherein a pre-combustion chamber 6 of the jet ignition combustion system of the hydrogen internal combustion engine comprises a spark plug connecting section and a jet cavity shell connected with the spark plug connecting section, and the spark plug connecting section is provided with a threaded hole used for connecting a spark plug 5 and communicated with the jet cavity shell. The ratio of the volume of the precombustion chamber 6 to the volume of the main combustion chamber is 2%, and the spark plug 5 ignites the mixture in the precombustion chamber 6 to ignite the main combustion chamber.

The efflux chamber shell is to the convex spherical crown shape structure of main combustion chamber direction, and a plurality of jet orifices are located the efflux chamber shell, and the screw hole is close to the one end of efflux chamber shell and offers the domatic 8 of toper that the diameter crescent, and the domatic 8 of toper can form tiny tumble in efflux chamber shell inside to this can improve the mobility of 6 inside gases in precombustion chamber, realizes sweeping of 6 inside waste gases in precombustion chamber.

The jet holes specifically comprise an upper layer jet hole 10 and a lower layer jet hole 9 which are positioned on the jet cavity shell, the number of the lower layer jet holes 9 is 6-8, the lower layer jet holes 9 are uniformly distributed around the circumference of the axial direction of the pre-combustion chamber 6, and the angle between the opening direction of the lower layer jet holes 9 and the axial direction of the pre-combustion chamber 6 is 45-75 degrees so as to jet homogeneous jet to the main combustion chamber, and the flame in the jet flow ignites or activates the mixed gas in the main combustion chamber.

The aperture of the upper-layer jet hole 10 is larger than that of the lower-layer jet hole 9, and the aperture of the upper-layer jet hole 10 is larger than 1.5mm, so that the layered spraying of flame and active base is facilitated. The number of the upper-layer jet holes 10 is 3-5, the upper-layer jet holes 10 are positioned on one side close to the conical slope surface 8, and the hole opening direction of the upper-layer jet holes 10 is parallel to the conical slope surface 8. The mixed gas entering the pre-combustion chamber 6 from the upper-layer jet hole 10 further improves the fluidity of the gas in the pre-combustion chamber 6, and realizes the purging of the waste gas in the pre-combustion chamber 6.

In some alternative embodiments: referring to fig. 1, the embodiment of the present application provides a jet ignition combustion system for a hydrogen internal combustion engine, in which a ball socket with an upward opening is arranged on the top surface of a piston 5, and when the piston 5 reaches the vicinity of a top dead center, a pre-combustion chamber 6 in a main combustion chamber is at least partially arranged in the ball socket, so that the compression ratio of the main combustion chamber reaches 15 to 18.

When the piston 5 reaches the vicinity of the top dead center, the pre-combustion chamber 6 is positioned at the center of the ball socket of the piston 5 to improve the compression ratio of the main combustion chamber and release the maximum explosion energy to improve the power output of the engine. The outlet of the main ejector 2 is provided with an ejection cap, the ejection cap is provided with a plurality of ejection holes, the diameter of each ejection hole is larger than 1.5mm, and the direction of the plurality of ejection holes is obtained by respectively connecting a plurality of uniformly distributed points on the circles of the top plane of the piston and the plane of the lower surface of the ejection cap.

In some alternative embodiments: referring to fig. 3, the embodiment of the application provides a jet ignition combustion system of a hydrogen internal combustion engine, which further comprises a secondary injector 7 fixedly connected with a cylinder cover 1 and extending into a pre-combustion chamber 6, wherein the injection quantity and volume of the secondary injector 7 are smaller than those of the main injector 2.

The auxiliary injector 7 is used for injecting hydrogen into the pre-combustion chamber 6 at the last stage of the compression stroke so as to improve the concentration of the mixture before ignition and effectively ensure the success rate of ignition, thereby forming an active jet-type jet ignition combustion system of the hydrogen internal combustion engine.

The cylinder head 1 is also provided with an air inlet passage (not shown) and an air outlet passage (not shown) which are communicated with the main combustion chamber, the air inlet passage is provided with an air inlet valve (not shown) for opening and closing the air inlet passage, and the air outlet passage is provided with an exhaust valve (not shown) for opening and closing the air outlet passage.

Referring to fig. 1 and 2, a second aspect of the embodiments of the present application provides an injection control method for a jet ignition combustion system of a hydrogen internal combustion engine, which uses the passive jet type hydrogen internal combustion engine jet ignition combustion system according to one or more of the embodiments described above, the method including the steps of:

step 101, the main injector 2 injects hydrogen to the main combustion chamber for the first time according to the rotation speed of the engine within the range of 138-118 degrees before top dead center, the hydrogen and fresh air form richer mixed gas outside the pre-combustion chamber 6, and the excess air coefficient lambda of the richer mixed gas is between 1.5-2.

102, along with the upward movement of the piston 3, the mixed gas in the main combustion chamber is pressed into the pre-combustion chamber 6 through the upper-layer jet holes 10 and the lower-layer jet holes 9, and under the flow guiding effect of the inner conical slope 8 of the pre-combustion chamber 6, tumble flow is formed in the pre-combustion chamber 6 to purge the waste gas in the pre-combustion chamber 6.

Step 103, before the air inlet valve is closed and the pressure of the main combustion chamber rises to 12.5bar, the main injector 2 injects hydrogen to the main combustion chamber for the second time so as to meet the power output of the engine.

And 104, when the piston 3 reaches the vicinity of the top dead center, controlling the spark plug 5 to carry out one or more times of ignition by the controller, wherein the mixed gas in the pre-combustion chamber 6 is ignited, so that the pressure in the pre-combustion chamber 6 is increased, and the pressure difference is established between the pre-combustion chamber 6 and the main combustion chamber.

Step 105, the mixture is combusted in the precombustion chamber 6 to release heat, due to the existence of the pressure difference, the precombustion chamber 6 generates a homogeneous jet flow which is jetted to the main combustion chamber, and the flame in the jet flow further ignites or activates the mixture in the main combustion chamber.

Referring to fig. 3, a third aspect of the embodiments of the present application provides an injection control method for a jet ignition combustion system of a hydrogen internal combustion engine, which uses the active jet type hydrogen internal combustion engine jet ignition combustion system according to one or more of the embodiments, and the method includes the following steps:

step 101, after the air inlet valve is closed, the main injector 2 starts to inject hydrogen into the main combustion chamber, and the hydrogen and fresh air form mixed gas outside the pre-combustion chamber.

102, in the ascending process of the piston 3, the mixed gas in the main combustion chamber is pressed into the pre-combustion chamber 6 through the upper-layer jet hole 10 and the lower-layer jet hole 9.

103, injecting hydrogen into the pre-combustion chamber 6 by the auxiliary injector 7 at the end of the compression stroke to enhance the concentration of the mixed gas in the pre-combustion chamber 6 and balance the pressure difference between the inside and the outside of the pre-combustion chamber 6; the injection triggering time of the auxiliary injector 7 is within the range that the air inlet valve is closed to 60 degrees, the auxiliary injector 7 injects hydrogen to effectively increase the internal air-fuel ratio of the pre-combustion chamber 6, and the internal and external pressure difference in the pre-combustion chamber 6 in the compression stroke stage is small, so that the hydrogen in the pre-combustion chamber 6 can be prevented from entering the main combustion chamber.

And 104, when the piston 3 reaches the vicinity of the top dead center, controlling the spark plug 5 to carry out one or more times of ignition by the controller, wherein the mixed gas in the pre-combustion chamber 6 is ignited, so that the pressure in the pre-combustion chamber 6 is increased, and the pressure difference is established between the pre-combustion chamber 6 and the main combustion chamber.

Step 105, the mixture is combusted in the pre-combustion chamber 6 to release heat, due to the existence of pressure difference, the pre-combustion chamber 6 generates a homogeneous jet flow which is jetted to the main combustion chamber, flame in the jet flow further ignites or activates the mixture in the main combustion chamber, and the jet flow ignition is beneficial to the efficient operation of the engine.

Principle of operation

The embodiment of the application provides a jet ignition combustion system and a jet control method of a hydrogen internal combustion engine, and the jet ignition combustion system of the hydrogen internal combustion engine is provided with the hydrogen internal combustion engine, wherein the hydrogen internal combustion engine comprises a cylinder body 4 and a piston 3 connected in the cylinder body 4 in a sliding manner, the top of the cylinder body 1 is provided with a cylinder cover 1, and a main combustion chamber is formed among the cylinder body 4, the cylinder cover and the piston; a main injector 2, the main injector 2 being fixed to the cylinder head and extending into the main combustion chamber, the main injector 2 being configured to inject hydrogen into the main combustion chamber at an initial stage of a compression stroke and at a final stage of the compression stroke, respectively;

the precombustion chamber 6 is fixedly connected with the cylinder cover 1 and is positioned on the central axis of the piston 3, a plurality of jet holes communicated with the main combustion chamber are formed in the precombustion chamber 6, and the piston 3 presses the mixed gas in the main combustion chamber into the precombustion chamber 6 through the jet holes in the compression stroke; and the spark plug 5 is fixedly connected with the pre-combustion chamber 6, extends into the pre-combustion chamber 6, and the spark plug 5 is used for igniting the mixed gas in the pre-combustion chamber 6 when the piston 3 reaches the position near the top dead center so as to generate a homogeneous jet flow to ignite the main combustion chamber.

Therefore, the jet ignition combustion system of the hydrogen internal combustion engine can be divided into an active jet ignition combustion system and a passive jet ignition combustion system. The spark plug 5 of the pre-combustion chamber 6 allows decoupling of the pre-combustion chamber 6 and the main combustion chamber, raising the mixture dilution limit. The high dilution of the mixture reduces the risk of pre-ignition, knock, and increases power, torque, and BTE. The hydrogen and air mixture is ignited and combusted under high compression conditions, making the combustion process efficient and stable. The gas plasma generated by the pre-combustion chamber 6 enters the main combustion chamber through a plurality of jet holes, and the gas mixture in the main combustion chamber can be quickly and uniformly ignited due to high energy content. The combustion chamber can generate ultra-clean and effective combustion effect in the whole combustion chamber, and almost or not generate pollutants such as nitrogen oxides and the like.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are merely for convenience of describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising one of 8230; \8230;" 8230; "does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A jet-ignited combustion system for a hydrogen internal combustion engine, comprising:

the hydrogen internal combustion engine comprises a cylinder body (4) and a piston (3) which is connected in the cylinder body (4) in a sliding manner, wherein a cylinder cover (1) is arranged at the top of the cylinder body (4), and a main combustion chamber is formed among the cylinder body (4), the cylinder cover (1) and the piston (3) together;

the main injector (2) is fixed on the cylinder cover (1) and extends into the main combustion chamber, and the main injector (2) is used for injecting hydrogen into the main combustion chamber at the initial stage and the final stage of a compression stroke respectively;

the pre-combustion chamber (6) is fixedly connected with the cylinder cover (1) and is positioned on the central axis of the piston (2), a plurality of jet holes communicated with the main combustion chamber are formed in the pre-combustion chamber (6), and the piston (3) presses mixed gas in the main combustion chamber into the pre-combustion chamber (6) through the jet holes in a compression stroke;

the spark plug (5), the spark plug (5) is connected with the precombustion chamber (6) fixedly and stretches into the precombustion chamber (6), and the spark plug (5) is used for the piston (3) to reach near top dead center and ignite the mixture in the precombustion chamber (6) so as to produce the homogeneous jet flow to ignite the main combustion chamber.

2. A jet ignition combustion system for a hydrogen internal combustion engine as defined in claim 1, wherein:

the pre-combustion chamber (6) comprises a spark plug connecting section and a jet flow cavity shell connected with the spark plug connecting section, and the spark plug connecting section is provided with a threaded hole which is used for connecting a spark plug (5) and communicated with the jet flow cavity shell;

the jet cavity shell is of a spherical crown structure protruding towards the direction of the main combustion chamber, the plurality of jet holes are formed in the jet cavity shell, and one end, close to the jet cavity shell, of each threaded hole is provided with a conical slope surface (8) with the diameter gradually increasing.

3. A jet ignition combustion system for a hydrogen internal combustion engine as defined in claim 2, wherein:

the jet holes comprise an upper layer jet hole (10) and a lower layer jet hole (9) which are positioned on the jet cavity shell, the lower layer jet holes (9) are uniformly distributed around the circumference of the axial direction of the pre-combustion chamber (6), and the angle between the opening direction of the lower layer jet hole (9) and the axial line of the pre-combustion chamber (6) is 45-75 degrees;

the aperture of upper jet orifice (10) is greater than the aperture of lower floor jet orifice (9), upper jet orifice (10) are located the one side that is close domatic (8) of toper, just the trompil direction of upper jet orifice (10) is parallel to each other with domatic (8) of toper.

4. A jet ignition combustion system for a hydrogen internal combustion engine as defined in claim 3, wherein:

the ratio of the volume of the pre-combustion chamber (6) to the volume of the main combustion chamber is 2%, the number of the upper-layer jet holes (10) is 3-5, and the number of the lower-layer jet holes (9) is 6-8.

5. A jet ignition combustion system for a hydrogen internal combustion engine as defined in claim 1, wherein:

the top surface of the piston (3) is provided with a ball socket with an upward opening, when the piston (3) reaches the vicinity of a top dead center, a pre-combustion chamber (6) in the main combustion chamber is at least partially positioned in the ball socket, and the compression ratio of the main combustion chamber is 15-18.

6. A jet ignition combustion system for a hydrogen internal combustion engine as defined in claim 1, wherein:

the outlet of the main ejector (2) is provided with an ejection cap, the ejection cap is provided with a plurality of ejection holes, the diameter of each ejection hole is larger than 1.5mm, and the direction of each ejection hole is obtained by connecting a plurality of points which are uniformly distributed on the top plane of the piston (3) and the circle of the lower surface plane of the ejection cap.

7. A jet ignition combustion system for a hydrogen internal combustion engine as defined in claim 1, wherein:

the pre-combustion chamber structure is characterized by further comprising a secondary injector (7) which is fixedly connected with the cylinder cover (1) and extends into the pre-combustion chamber (6), wherein the secondary injector (7) is used for injecting hydrogen into the pre-combustion chamber (6) at the tail stage of a compression stroke.

8. A jet ignition combustion system for a hydrogen internal combustion engine as defined in claim 1, wherein:

the cylinder cover (1) is further provided with an air inlet channel and an air outlet channel which are communicated with the main combustion chamber, the air inlet channel is provided with an air inlet valve for opening and closing the air inlet channel, and the air outlet channel is provided with an exhaust valve for opening and closing the air outlet channel.

9. An injection control method of a jet ignition combustion system of a hydrogen internal combustion engine, characterized in that the method uses the jet ignition combustion system of the hydrogen internal combustion engine according to any one of claims 1 to 8, the method comprising the steps of:

the main ejector (2) ejects hydrogen to the main combustion chamber for the first time within the range of 138-118 degrees before top dead center according to the rotating speed of the engine, and the hydrogen and fresh air form richer mixed gas outside the pre-combustion chamber (6) under the action of in-cylinder airflow;

along with the upward movement of the piston (3), the mixed gas in the main combustion chamber is pressed into the pre-combustion chamber (6) through a plurality of jet holes, and under the flow guide effect of the inner conical slope (8) of the pre-combustion chamber (6), tumble flow is formed in the pre-combustion chamber (6) to sweep the waste gas in the pre-combustion chamber (6);

before the air inlet valve is closed and the pressure of the main combustion chamber rises to 12.5bar, the main injector (2) injects hydrogen to the main combustion chamber for the second time so as to meet the power output of the engine;

when the piston (3) reaches the vicinity of the top dead center, the controller controls the spark plug (5) to carry out one or more times of ignition, and at the moment, the mixed gas in the pre-combustion chamber (6) is ignited, so that the pressure in the pre-combustion chamber (6) is increased, and the pressure difference is established between the pre-combustion chamber (6) and the main combustion chamber;

the mixed gas is combusted in the pre-combustion chamber (6) to release heat, due to the existence of pressure difference, the pre-combustion chamber (6) generates a homogeneous jet flow which is jetted to the main combustion chamber, and the flame in the jet flow further ignites or activates the mixed gas in the main combustion chamber.

10. An injection control method of a jet ignition combustion system of a hydrogen internal combustion engine, characterized in that the method uses the jet ignition combustion system of the hydrogen internal combustion engine according to any one of claims 1 to 8, the method comprising the steps of:

after the air inlet valve is closed, the main ejector (2) starts to eject hydrogen to the main combustion chamber, and the hydrogen and fresh air form mixed gas outside the pre-combustion chamber (6);

in the ascending process of the piston (3), the mixed gas in the main combustion chamber is pressed into the pre-combustion chamber (6) through a plurality of jet holes;

the auxiliary injector (7) injects hydrogen into the pre-combustion chamber (6) at the last stage of the compression stroke so as to enhance the concentration of the mixed gas in the pre-combustion chamber (6) and balance the pressure difference between the inside and the outside of the pre-combustion chamber (6);

when the piston (3) reaches the vicinity of the top dead center, the controller controls the spark plug (5) to carry out one or more times of ignition, and at the moment, the mixed gas in the pre-combustion chamber (6) is ignited, so that the pressure in the pre-combustion chamber (6) is increased, and the pressure difference is established between the pre-combustion chamber (6) and the main combustion chamber;

the mixed gas is combusted in the pre-combustion chamber (6) to release heat, due to the existence of pressure difference, the pre-combustion chamber (6) generates a homogeneous jet flow which is jetted to the main combustion chamber, and the flame in the jet flow further ignites or activates the mixed gas in the main combustion chamber.

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