CN116857099A - Straight air passage hydrogen internal combustion engine - Google Patents

Abstract

The application relates to the technical field of hydrogen engines, in particular to a straight-gas-passage hydrogen internal combustion engine. The straight-gas-passage hydrogen internal combustion engine comprises a cylinder, a piston and a direct injection nozzle, wherein an air inlet valve and an air outlet valve are arranged on a cylinder cover of the cylinder; the piston is arranged in the cylinder, and the surface of the piston, which is close to the cylinder cover, is concave so that the piston is bowl-shaped; the direct injection nozzle is arranged on the cylinder cover, and is far away from the exhaust valve and close to the intake valve. The embodiment of the application provides a straight air passage hydrogen internal combustion engine to solve the problem of knocking and flame extinction caused by insufficient in-cylinder mixing of an in-cylinder direct injection internal combustion engine in the related art.

Description

Straight air passage hydrogen internal combustion engine

Technical Field

The application relates to the technical field of hydrogen engines, in particular to a straight-gas-passage hydrogen internal combustion engine.

Background

The hydrogen internal combustion engine is mainly classified into port injection and in-cylinder direct injection according to the fuel supply manner. The internal combustion engine with direct injection of hydrogen in a cylinder can fundamentally avoid backfire and greatly eliminate the probability of occurrence of pre-combustion and knocking.

However, in the in-cylinder direct injection hydrogen internal combustion engine, insufficient in-cylinder mixing at the end of the compression stroke may exist in an excessively rich and lean mixture region, and after ignition, the excessively rich region is liable to produce spontaneous combustion before the arrival of the flame front cover to cause knocking, and the excessively lean region may slow down the flame propagation speed and even extinguish the flame, resulting in a decrease in efficiency and a large amount of unburned hydrogen in the exhaust gas. In addition, the concentration fluctuation of the mixed gas near the spark plug between the cycles is larger due to insufficient mixing in the cylinder, so that larger cycle fluctuation is caused, and the phenomenon of fire even occurs due to low concentration near part of the cycle spark plug.

Disclosure of Invention

The embodiment of the application provides a straight air passage hydrogen internal combustion engine, which aims to solve the problem of knocking and flame extinction caused by insufficient in-cylinder mixing of an in-cylinder direct injection internal combustion engine in the related technology.

To achieve the above object, an embodiment of the present application provides a straight-gas-passage hydrogen internal combustion engine, comprising:

the cylinder is provided with an air inlet valve and an air outlet valve on a cylinder cover;

the piston is arranged in the cylinder, and the surface of the piston, which is close to the cylinder cover, is concave so that the piston is bowl-shaped;

and the direct injection nozzle is arranged on the cylinder cover, is far away from the exhaust valve and is close to the intake valve.

In some embodiments, the inlet comprises a straight inlet comprising a first inlet and a second inlet, with an avoidance zone between the first inlet and the second inlet;

the direct injection nozzle is arranged at the avoidance area.

In some embodiments, the included angle α between the straight intake duct and the cylinder head is 20 ° to 30 °. Preferably, the angle α takes the value of 30 °.

In some embodiments, the piston comprises an arc-shaped part, and the concave surface of the arc-shaped part is arranged towards one side where the cylinder cover is positioned; the piston moves from the bottom dead center to the top dead center, compresses gas in the cylinder, and the piston moves from the top dead center to the bottom dead center again to ignite and enable the gas in the cylinder to do work, and the arc-shaped part can strengthen tumble flow, so that the gas mixture in the cylinder is fully mixed.

The direct injection nozzle comprises a nozzle end positioned in the cylinder, wherein the nozzle end is inclined and extends from one end close to the exhaust valve to one end far away from the exhaust passage to the arc-shaped part.

In some embodiments, a combustion chamber is disposed between the piston and the cylinder;

the cylinder head is provided with the jet flow chamber, the jet flow chamber includes spark plug and ignition inner chamber, just the jet flow chamber is connected with hydrogen transfer line, hydrogen transfer line and ignition inner chamber intercommunication, ignition inner chamber and combustion chamber intercommunication, the spark plug meets with the ignition inner chamber.

In some embodiments, the ignition cavity includes an ignition portion and a throat portion, the ignition portion is in communication with the throat portion, and an inner diameter of the ignition portion decreases from an end distal from the throat portion to an end connected to the throat portion, and after ignition by the spark plug, the flame/gas flow gradually accelerates with the gradually decreasing diameter ignition portion and enters the combustion chamber through the throat portion.

In some embodiments, the ignition portion is funnel-shaped. The throat part is a cylindrical channel, the axis of the throat part is consistent with that of the ignition part, and flame/air flow enters the throat part from the ignition part, so that the flame/air flow keeps straight running, radial fluctuation is reduced, and the flame speed entering the combustion chamber is stable.

In some embodiments, when the piston is at top dead center, the combustion chamber is a top dead center combustion chamber, and the ignition cavity has a volume that is 2% -3% of the volume of the top dead center combustion chamber.

In some embodiments, the jet chamber includes a jet aperture, the jet chamber communicates with the combustion chamber through the jet aperture, and the jet chamber is disposed between the intake and exhaust passages.

In some embodiments, the jet chamber comprises a connector, the connector is arranged at one end of the ignition inner cavity far away from the spark plug and is at least partially positioned in the combustion chamber, and the jet holes are multiple and uniformly arranged on the connector.

The technical scheme provided by the application has the beneficial effects that:

the embodiment of the application provides a straight-gas-passage hydrogen internal combustion engine, because a piston is used, in the process that the piston moves from a top dead center to a bottom dead center in a cylinder, gas enters the cylinder through an air inlet passage and an air inlet valve, on one hand, the gas input by the air inlet passage is impacted on a bowl-shaped piston, a large-scale vortex structure is formed in the cylinder along an arc-shaped piston pit molded line, the flow of gas mixing in the cylinder is enhanced, the gas mixing in the cylinder can be optimized, the combustion speed is accelerated, and on the other hand, a direct injection nozzle is arranged at one end of the air inlet valve far away from an exhaust valve, and the tumble is enhanced to the greatest extent;

after air intake is completed, the piston moves from the bottom dead center to the top dead center, the air in the cylinder is compressed, the piston moves from the top dead center to the bottom dead center again, the air in the cylinder is ignited and is enabled to do work, the bowl-shaped piston can strengthen tumble flow, and the air-fuel mixture in the cylinder is fully mixed, so that the problems of knocking and flame extinction caused by insufficient mixing in the cylinder of the direct injection internal combustion engine in the related art can be solved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of the direction of gas movement in a piston of a straight air inlet channel and a straight injection nozzle in a straight air channel hydrogen internal combustion engine according to an embodiment of the present application;

FIG. 2 is a front view of a straight-gas-path hydrogen internal combustion engine provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of a straight airway according to an embodiment of the present application;

FIG. 4 is a top view of a straight-gas-path hydrogen internal combustion engine provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of a jet chamber and piston in a straight-gas-path hydrogen internal combustion engine according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a jet chamber according to an embodiment of the present application.

In the figure: 1. a straight air inlet channel; 11. an intake valve; 12. a first air inlet channel; 13. a second air inlet channel; 2. an exhaust passage; 21. an exhaust valve; 3. a direct injection nozzle; 31. a nozzle end; 4. a piston; 41. an arc-shaped portion; 5. a combustion chamber; 6. a jet chamber; 61. a spark plug; 62. a hydrogen gas delivery line; 63. an ignition cavity; 631. an ignition section; 632. a throat; 64. a connector; 641. and jet holes.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The embodiment of the application provides a straight air passage hydrogen internal combustion engine, which can solve the problem of knocking and flame extinction caused by insufficient in-cylinder mixing of an in-cylinder direct injection internal combustion engine in the related technology.

Referring to fig. 1 to 6, an embodiment of the present application provides a straight-gas-passage hydrogen internal combustion engine, which includes a cylinder including a cylinder head provided with an intake valve 11 and an exhaust valve 21 for installation of an intake passage, an exhaust passage 2, respectively, a piston 4, and a direct injection nozzle 3;

further, the piston is disposed in the cylinder, and as shown in fig. 1 to 2, the surface of the piston 4 near the cylinder head is concave so that the piston 4 takes a bowl shape; specifically, the piston 4 includes an arc portion 41, the arc portion 41 is located near one end of the cylinder head, and a concave surface of the arc portion 41 is provided toward the side where the cylinder head is located.

Further, the direct injection nozzle 3 is arranged on the cylinder cover, the direct injection nozzle 3 is far away from the exhaust valve 21 and is close to the intake valve 11, so that the direct injection nozzle 3 is closer to the intake valve 11, the hydrogen sprayed out by the direct injection nozzle 3 and the air entering through the intake valve 11 are mixed to a greater extent, the bowl-shaped piston 4 is combined, and a large-scale vortex structure is formed in the cylinder along the pit-shaped line of the shallow bowl-shaped piston 4 after the arc-shaped part 41 of the piston 4 is impacted, so that the full mixing is realized.

The embodiment of the application provides a straight-gas-passage hydrogen internal combustion engine, because a piston 4 is used, in the process that the piston 4 moves from a top dead center to a bottom dead center in a cylinder, gas enters the cylinder through an intake valve 11, on one hand, the gas input by the intake valve 11 is impacted onto an arc-shaped part 41 of the piston 4, a large-scale vortex structure is formed in the cylinder along the pit molded line of the arc-shaped piston 4, the flow of gas mixing in the cylinder is enhanced, the gas mixing in the cylinder can be optimized, the combustion speed is accelerated, and on the other hand, a direct injection nozzle 3 is arranged at one end of the intake valve 11 far away from an exhaust valve 21, the mixing time is prolonged, and the tumble is enhanced to the greatest extent;

after the air intake is completed, the piston 4 moves from the bottom dead center to the top dead center, the cylinder gas is compressed, the piston 4 moves from the top dead center to the bottom dead center again, the cylinder gas is ignited and is enabled to do work, the arc-shaped part 41 can strengthen the tumble flow, and the mixture gas in the cylinder is fully mixed, so that the problems of knocking and flame extinction caused by insufficient in-cylinder mixing of the in-cylinder direct injection internal combustion engine in the related art can be solved.

Specifically, the piston 4 is movably disposed in the cylinder, and the piston 4 is connected with a driving device for driving the piston 4 to move along the length direction of the cylinder, and the piston 4 moves in the cylinder, wherein the position where the top of the piston 4 reaches the highest point is called top dead center, the position where the piston 4 moves in the cylinder and the top of the piston 4 reaches the lowest point is called bottom dead center.

In some alternative embodiments, referring to fig. 1 and 2, the straight-channel hydrogen internal combustion engine further includes an intake channel and an exhaust channel 2, the intake channel and the exhaust channel 2 being provided on the cylinder head through an intake valve 11 and an exhaust valve 21, respectively, and being used for air intake and gas exhaust, respectively.

Optionally, as shown in fig. 4, the air inlet includes a straight air inlet 1, the straight air inlet 1 includes a first air inlet 12 and a second air inlet 13, an avoidance area is formed between the first air inlet 12 and the second air inlet 13, and the direct injection nozzle 3 is disposed at the avoidance area to ensure that the flow direction of the hydrogen injection is the same as the air inlet direction of the air passage, so as to strengthen the tumble flow to the greatest extent, optimize the in-cylinder gas mixture, and accelerate the combustion speed.

Referring to fig. 1 and 2 again, fig. 1 shows the gas movement directions of the direct injection nozzle 3 and the direct injection channel 1 in the piston 4 and the cylinder, and it can be seen that when the direct injection nozzle 3 is disposed in the avoidance area, the hydrogen sprayed from the direct injection nozzle 3 moves together with the air entering from the direct injection channel 1 and is fully mixed, after striking the piston 4, a large-scale vortex structure is formed in the cylinder along the pit-shaped line of the shallow bowl-shaped piston 4, so that more uniform mixed gas can be obtained at the top dead center ignition moment, and meanwhile, the turbulent energy and the tumble intensity are higher, the flame propagation speed can be accelerated, and the thermal efficiency is improved.

It should be noted that, due to space problems in the gas engine, the direct injection nozzle 3 needs to be disposed between the intake valve 11 and the exhaust valve 21, and compared with a mode of disposing the direct injection nozzle 3 at an end of the intake valve 11 far from the exhaust valve 21, mixing of hydrogen and air may lack a certain period of mixing, that is, after the air enters the cylinder from the intake valve 11, the air still needs to move for a certain period of time to be mixed with the hydrogen. In this embodiment, the direct injection nozzle 3 is disposed at one end of the intake valve 11 away from the exhaust valve 21 (disposed in the avoidance area), and after the hydrogen is sprayed, the movement path of the hydrogen passes through the intake valve 11, so that the hydrogen and air can be mixed to a greater extent. Accordingly, there are two exhaust passages 2, and they are provided corresponding to the first intake passage 12 and the second intake passage 13.

Referring to fig. 2, the joint of the straight air inlet channel 1 and the air inlet valve 11 has a certain limit on the arrangement of the straight air inlet channel 1, and the space above the cylinder cover is limited, so that air is limited to pass through the joint of the straight air inlet channel 1 and the air inlet valve, if the air inlet channel such as the air outlet channel 2 is in a bent pipe design, after the air enters the cylinder from the air inlet channel in the shape of the bent pipe, the air flow direction is changed from the bent position of the bent pipe, namely, the air flow direction is changed into the vertical direction, so that the air flow direction entering the cylinder is more inclined downwards, the transverse force is smaller, the formation of tumble is unfavorable, and the mixing is poor;

the air inlet is arranged as a straight air inlet 1 shown in fig. 2, the air flow direction is always consistent, and after entering the air cylinder, the movement direction is shown as the air flow (1) in fig. 1, so that the transverse force is larger, and the improvement of the rolling flow strength is facilitated.

In some alternative embodiments, as shown in fig. 1, the direct injection nozzle 3 includes a nozzle end 31 located in the cylinder, the nozzle end 31 being inclined and extending from an end near the exhaust passage 2 to an end remote from the exhaust passage to an arcuate portion 41. That is, as shown in fig. 1, the opening of the nozzle end 31 is provided toward the straight intake duct 1 so that the hydrogen gas ejected from the nozzle end 31 moves in the movement direction shown in (2) in fig. 1.

The combined direct injection nozzle 3 is arranged in an avoidance area between the first air inlet channel 12 and the second air inlet channel 13, and the nozzle end 31 is opened towards the direction of the exhaust valve 21, so that the flow direction of hydrogen sprayed out of the direct injection nozzle 3 is the same as the air inlet direction of the intake valve 11, namely the (1) air flow and the (2) hydrogen flow shown in fig. 1, and the tumble is intensified to the greatest extent.

Specifically, the cylinder includes a cylinder head, i.e., a sealing cover of the cylinder, with a combustion chamber 5 between the cylinder and a concave surface of the piston 4, i.e., a space where gases are mixed as shown in fig. 1, and a nozzle end 31 is located in the combustion chamber 5.

In some alternative embodiments, the angle alpha between the straight intake duct 1 and the cylinder head is 20 deg. to 30 deg. as shown in figures 1 to 3. In particular, the determination of the angle α depends on the structure of the intake valve on the cylinder head and the processing boundary of the cylinder head, and 20 ° to 30 ° are data after a plurality of tests, and in particular, with respect to α having a larger angle, for example, a value of 60 °, the lateral force of the gas entering the cylinder is larger, while the downward force is smaller, which is advantageous for the formation of the tumble flow in the cylinder, and the tumble flow ratio is larger, so that the tumble flow strength can be enhanced. The reason for the smaller included angle α is that when air enters the cylinder from the straight intake duct 1, the transverse movement force is stronger, and the movement direction of the air flow in the cylinder is further as shown in the air flow (1) in fig. 1.

Preferably, as shown in connection with fig. 2, the intake valve 11 has a certain height, and is connected with the straight intake duct 1, so that the included angle α between the straight intake duct 1 and the cylinder head is 30 °, no interference is caused to the cylinder head, and a strong in-cylinder tumble is formed.

In some alternative embodiments, see fig. 5, a combustion chamber 5 is provided between the piston 4 and the cylinder, a jet chamber 6 is provided on the cylinder head, and the jet chamber 6 communicates with the combustion chamber 5 for ignition as a pre-combustion chamber. Specifically, the jet chamber 6 includes a spark plug 61 and an ignition inner chamber 63, and the jet chamber 6 is communicated with a hydrogen gas delivery pipe 62, the ignition inner chamber 63 is communicated with the combustion chamber 5, and the spark plug 61 is connected with the ignition inner chamber 63 for igniting the ignition inner chamber 63 after hydrogen gas is delivered from the hydrogen gas delivery pipe 62 into the ignition inner chamber 63. The hydrogen delivery pipe 62 delivers hydrogen gas so that the hydrogen concentration near the ignition plug 61 is high, and controls the air-fuel ratio inside the jet chamber 6 to be at a rich level with respect to the main combustion chamber (combustion chamber 5), thereby ensuring the air-fuel ratio near the ignition plug, avoiding misfire and cyclic fluctuation.

The hydrogen conveying pipeline 62 is communicated with the ignition inner cavity 63 and conveys hydrogen to the ignition inner cavity 63, ignition in the ignition inner cavity 63 is realized, and the hydrogen is conveyed to the combustion chamber 5, so that the combustion speed can be increased, knocking is avoided, and the heat efficiency is improved.

The hydrogen has the physical and chemical characteristics of high heat value and low ignitable ignition energy as fuel, and abnormal combustion phenomena such as tempering, spontaneous combustion knocking and the like easily occur in practical application; in a low-pressure direct-injection hydrogen internal combustion engine, the injection timing and the injection pulse width of hydrogen change along with the load rotating speed, which means that the mixing time of the hydrogen and the air in a cylinder is different under different working conditions, the concentration of the mixed gas near a spark plug is difficult to keep consistent at the ignition moment, and the combustion stability is influenced; the present embodiment provides an independent jet chamber 6 to control the air-fuel ratio inside the jet chamber 6 to be at a richer level relative to the combustion chamber 5, thereby ensuring the air-fuel ratio near the ignition plug 61 and avoiding misfire and cyclic fluctuation.

Optionally, in this embodiment, an independent jet chamber 6 is provided, where the jet chamber 6 is connected to an independent hydrogen delivery pipe 62 and an ignition cavity 63, and at the moment of-360 ° to-180 ° ATDC, hydrogen accounting for 3% of the total fuel is injected into the ignition cavity 63 of the jet chamber 6, so as to control the air-fuel ratio in the jet chamber to be at a richer level relative to the main combustion chamber, thereby ensuring the air-fuel ratio near the spark plug, and avoiding fire and cyclic fluctuation.

Further, referring to fig. 5 and 6, the ignition chamber 63 includes an ignition portion 631 and a throat portion 632, the ignition portion 631 communicates with the throat portion 632, and the inner diameter of the ignition portion 631 decreases from an end distant from the throat portion 632 to an end connected to the throat portion 632.

Further, the output end of the hydrogen delivery pipe 62 is close to the ignition position of the spark plug 61, so as to ensure the hydrogen concentration near the spark plug 61 and further ensure the ignition effect.

Specifically, the end of the ignition portion 631 with larger inner diameter is located at the end of the spark plug 61, after the spark plug 61 ignites, the flame/air flow accelerates gradually along with the ignition portion 631 with gradually reduced diameter, and then the throat 632 connected with the end of the ignition portion 631 with smaller diameter is combined, the throat 632 can be hollow and cylindrical, the throat 632 is consistent with the axis of the ignition portion 631, and the flame/air flow enters the throat 632 from the ignition portion 631, so that the flame/air flow keeps straight, and radial fluctuation is reduced.

The ignition is divided into a plurality of times, for example, in the case of two adjacent ignition processes, for example, in the case of the first ignition and the second ignition, the flame/gas flow can only go straight up and down from the throat 632 (along the axial direction of the throat 632) before entering the combustion chamber 5, and the radial speed is reduced, so that the flow speed between the first cycle and the second cycle (the cycle refers to the ignition cycle) is close, and the fluctuation between the cycles is as small as possible, and the flame speed entering the combustion chamber 5 is stable.

Preferably, as shown in connection with fig. 5 and 6, the ignition portion 631 is funnel-shaped.

In some alternative embodiments, referring to FIG. 6, jet chamber 6 includes a jet hole 641, jet chamber 6 communicates with combustion chamber 5 through jet hole 641, and jet chamber 6 is disposed between the intake and exhaust passages 2. Specifically, the flame/gas flow is injected into the combustion chamber 5 through the injection hole 641 to ignite the mixed gas in the combustion chamber 5.

Optionally, the jet chamber 6 includes a connector 64, where the connector 64 is disposed at an end of the ignition cavity 63 away from the spark plug 61 and at least partially located in the combustion chamber 5, and the jet holes 641 are plural and uniformly disposed on the connector 64.

As shown in fig. 6, the joint 64 is regarded as a sphere, and the sphere is mounted at one end of the throat 632 far from the ignition portion 631, and six jet holes 641 are provided at intervals along the surface of the sphere as shown in fig. 6, or 12 jet holes 641 are provided at intervals of 30 ° with respect to a cylinder head parallel to the reference surface, so that flame/air flow is uniformly injected into the combustion chamber.

The jet holes 641 are preferably circular holes, and when the number of the jet holes 641 is six, the aperture thereof may be 2mm, and when the number of the jet holes 641 is twelve, the aperture thereof may be 1.4 to 1.6mm.

In some alternative embodiments, when the piston 4 is at top dead center, the combustion chamber 5 is a top dead center combustion chamber and the volume of the ignition cavity 63 is 2% to 3% of the top dead center combustion chamber volume. As shown in fig. 5, the combustion chamber 5 is a top dead center combustion chamber; further, the piston 4 shown in fig. 1 and 2 is located at the bottom dead center, and the combustion chamber 5 is a bottom dead center combustion chamber.

Alternatively, the diameter of the throat 632 may be in the range of 3.6mm to 6.6mm, and the larger the volume of the ignition portion 631, the smaller the volume of the throat 632, and the smaller the size of at least one of the length and the diameter, under certain conditions of the volume of the ignition cavity 63. The diameter of the throat 632 is not less than 3.6mm, so that the accelerated flame/air flow passes through, the diameter is not more than 6.6mm, the flame/air flow is directly above, the radial fluctuation is reduced, and knocking is avoided.

In some alternative embodiments, the direct injection nozzle 3 injects hydrogen into the cylinder, the air inlet channel injects air into the cylinder, the hydrogen and the air are mixed in the cylinder, when the piston 4 moves from the bottom dead center to the top dead center, a part of mixed gas in the cylinder is pressed into the ignition cavity 63, at this time, the hydrogen in the ignition cavity 63 is thinner, the combustion speed is limited, and the incomplete combustion of the hydrogen is caused, so the hydrogen is conveyed to the ignition cavity 63 through the hydrogen conveying pipeline 62, the concentration of the hydrogen in the ignition cavity 63 is higher, the combustion is more sufficient, and the flame injected into the combustion chamber 5 drives the gas mixture in the combustion chamber 5, so the combustion is more sufficient and the efficiency is higher.

Preferably, the piston 4 is bowl-shaped as shown in fig. 1-2, and is specifically concave near the surface of the cylinder cover, gas enters the cylinder through the intake valve 11, on one hand, the gas input by the intake valve 11 impinges on the arc-shaped part 41 of the piston 4, and a large-scale vortex structure is formed in the cylinder along the arc-shaped pit line of the piston 4, so that the flow of gas mixing in the cylinder is enhanced, the gas mixing in the cylinder can be optimized, and the combustion speed is accelerated;

further, the air inlet is a straight air inlet 1, namely the air flow direction of the air inlet is always consistent, and after the air enters the air cylinder, the movement direction of the air inlet is shown as the air flow (1) in the figure 1, so that the trend of transverse movement is larger, and the improvement of the tumble strength is facilitated;

further, the direct injection nozzle 3 is arranged on the cylinder cover, the direct injection nozzle 3 is far away from the exhaust valve 21 and is close to the intake valve 11, so that the direct injection nozzle 3 is closer to the intake valve 11, the movement direction of hydrogen sprayed out by the direct injection nozzle 3 is shown as the (2) airflow in fig. 1, the air entering through the intake valve 11 can be mixed with the air to a greater extent, the bowl-shaped piston 4 is combined, and a large-scale vortex structure is formed in the cylinder along the pit-shaped line of the shallow bowl-shaped piston 4 after the arc-shaped part 41 of the piston 4 is impacted, so that the full mixing is realized.

The application provides a straight air passage hydrogen internal combustion engine, which has the following advantages:

reinforcing tumble flow: the straight air inlet channel 1 and the bowl-shaped piston 4 (which can be used for a flat bottom or a ridge-shaped cylinder cover) are adopted, meanwhile, the straight air inlet channel 1 is provided with a straight air injection nozzle 3 for injecting hydrogen at one end far away from the air outlet channel 2, the hydrogen injected from the straight air inlet channel 1 moves together with air entering from the straight air inlet channel 1 and is fully mixed, and a large-scale vortex structure is formed in the cylinder along the pit line of the bowl-shaped piston 4 after the hydrogen is impacted on the arc-shaped part 41 of the piston 4. By adopting the design scheme, the oil-gas mixture can be obviously optimized, more uniform mixed gas can be obtained at the ignition time of the upper dead point, and simultaneously, the flame propagation speed can be accelerated due to higher turbulence energy and tumble intensity, so that the thermal efficiency is improved;

jet ignition: in the case of large fluctuation of the mixture concentration near the spark plug 61, the jet chamber 6 is provided, the spark plug 61 and the independent hydrogen nozzle (i.e. the hydrogen delivery pipeline 62) are arranged in the jet chamber 6, the hydrogen delivery pipeline 62 performs injection with shorter time per cycle of compression stroke, and the injection is combined with the upward gas in the compression stroke (i.e. the mixture gas pressed into the ignition cavity 63 from the combustion chamber 5 when the piston 4 moves from the bottom dead center to the top dead center), so that the mixture gas near the spark plug 61 is ensured to be thicker, and the unstable combustion and the occurrence of the fire phenomenon are avoided. After the ignition of the spark plug 61, the ignition inner cavity 63 serves as a pre-combustion chamber, the emitted jet flame is injected into the cylinder through the jet hole 641 connected with the combustion chamber 5 to ignite the mixed gas, and the ignition energy of the ignition mode is higher than that of the pure spark plug 61, so that the hydrogen combustion can be accelerated, and the thermal efficiency is improved.

In the description of the present application, it should be noted that the azimuth or positional relationship indicated by the terms "upper", "lower", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of describing the present application and simplifying the description, and are not indicative or implying that the apparatus or element in question must have a specific azimuth, be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present application. Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication 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 according to the specific circumstances.

It should be 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. Moreover, 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 phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is only a specific embodiment of the application to enable those skilled in the art to understand or practice the 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 straight-gas-passage hydrogen internal combustion engine, characterized by comprising:

the cylinder is provided with an air inlet valve (11) and an air outlet valve (21) on a cylinder cover;

the piston (4) is arranged in the cylinder, and the surface of the piston (4) close to the cylinder cover is concave, so that the piston (4) is bowl-shaped;

and a direct injection nozzle (3) arranged on the cylinder cover, wherein the direct injection nozzle (3) is far away from the exhaust valve (21) and is close to the intake valve (11).

2. The straight airway hydrogen internal combustion engine of claim 1 wherein:

the air inlet comprises a straight air inlet (1), the straight air inlet (1) comprises a first air inlet (12) and a second air inlet (13), and an avoidance area is arranged between the first air inlet (12) and the second air inlet (13);

the direct injection nozzle (3) is arranged at the avoidance area.

3. The straight airway hydrogen internal combustion engine of claim 2 wherein:

the included angle alpha between the straight air inlet channel (1) and the cylinder cover is 20-30 degrees.

4. The straight airway hydrogen internal combustion engine of claim 1 wherein:

the piston (4) comprises an arc-shaped part (41), and the concave surface of the arc-shaped part (41) is arranged towards one side where the cylinder cover is positioned;

the direct injection nozzle (3) comprises a nozzle end (31) positioned in the cylinder, wherein the nozzle end (31) is inclined and extends from one end close to the exhaust valve (21) to one end far from the exhaust passage to the arc-shaped part (41).

5. The straight airway hydrogen internal combustion engine of claim 1 wherein:

a combustion chamber (5) is arranged between the piston (4) and the cylinder;

the cylinder head is provided with jet flow chamber (6), jet flow chamber (6) include spark plug (61) and ignition inner chamber (63), just jet flow chamber (6) are connected with hydrogen conveying pipeline (62), hydrogen conveying pipeline (62) and ignition inner chamber (63) intercommunication, ignition inner chamber (63) and combustion chamber (5) intercommunication, spark plug (61) meet with ignition inner chamber (63).

6. The straight airway hydrogen internal combustion engine of claim 5 wherein:

the ignition cavity (63) comprises an ignition part (631) and a throat part (632), the ignition part (631) is communicated with the throat part (632), and the inner diameter of the ignition part (631) is reduced from one end far away from the throat part (632) to one end connected with the throat part (632).

7. The straight airway hydrogen internal combustion engine of claim 6 wherein:

the ignition part (631) is funnel-shaped.

8. The straight airway hydrogen internal combustion engine of claim 6 wherein:

when the piston (4) is at the top dead center, the combustion chamber (5) is a top dead center combustion chamber, and the volume of the ignition inner cavity (63) is 2% -3% of the volume of the top dead center combustion chamber.

9. The straight airway hydrogen internal combustion engine of claim 6 wherein:

the jet flow chamber (6) comprises a jet flow hole (641), the jet flow chamber (6) is communicated with the combustion chamber (5) through the jet flow hole (641), and the jet flow chamber (6) is arranged between the air inlet passage and the exhaust passage (2).

10. The straight airway hydrogen internal combustion engine of claim 9 wherein:

the jet flow chamber (6) comprises a connector (64), the connector (64) is arranged at one end of the ignition inner cavity (63) far away from the spark plug (61) and is at least partially positioned in the combustion chamber (5), and a plurality of jet flow holes (641) are uniformly formed in the connector (64).