阅读说明：本技术 一种适用于高功率密度柴油机的非对称燃烧室系统 (Asymmetric combustion chamber system suitable for high power density diesel engine ) 是由 杨灿 成晓北 訾真 于 2021-01-25 设计创作，主要内容包括：本发明公开了一种适用于高功率密度柴油机的非对称燃烧室系统,属于柴油机相关技术领域,包括燃烧室、竖直设置于气缸盖中心的主喷油器和倾斜设置于气缸盖的副喷油器,所述燃烧室与所述活塞为偏心设置,所述燃烧室喉口圆心位于所述副喷油器一侧,以使所述燃烧室在所述副喷油器一侧的第一凹坑的容积大于远离所述副喷油器一侧的第二凹坑容积。本发明可以调节其副喷油一侧和远离副喷油器一侧的空气量的比例,使之与主副喷油器系统中副喷油器一侧的燃油较多,远离副喷油器一侧的燃油较少的特征适配,从而解决所述主副喷油器系统中因为燃油分布不均匀、不对称而导致的当量比分布的不均匀、不对称的问题。(The invention discloses an asymmetric combustion chamber system suitable for a high-power-density diesel engine, which belongs to the technical field related to diesel engines and comprises a combustion chamber, a main fuel injector vertically arranged in the center of a cylinder cover and an auxiliary fuel injector obliquely arranged on the cylinder cover, wherein the combustion chamber and a piston are eccentrically arranged, and the center of a throat of the combustion chamber is positioned on one side of the auxiliary fuel injector, so that the volume of a first pit of the combustion chamber on one side of the auxiliary fuel injector is larger than the volume of a second pit on one side far away from the auxiliary fuel injector. The invention can adjust the proportion of the air quantity at one side of the auxiliary fuel injector and one side far away from the auxiliary fuel injector, so that the air quantity is matched with the characteristic that more fuel oil is at one side of the auxiliary fuel injector and less fuel oil is at one side far away from the auxiliary fuel injector in the main fuel injector and auxiliary fuel injector system, thereby solving the problems of uneven and asymmetrical equivalent ratio distribution caused by uneven and asymmetrical fuel oil distribution in the main fuel injector and auxiliary fuel injector system.)

1. The utility model provides an asymmetric combustion chamber system suitable for high power density diesel engine, includes combustion chamber (6) of setting in piston (13), vertically sets up in main sprayer (2) of cylinder head (1) center and slope set up in vice sprayer (3) of cylinder head (1), its characterized in that:

the combustion chamber (6) and the piston (13) are arranged eccentrically, and the center of a throat of the combustion chamber (6) is located on one side of the auxiliary fuel injector (3), so that the volume of a first pit (10) of the combustion chamber (6) on one side of the auxiliary fuel injector (3) is larger than the volume of a second pit (11) on one side far away from the auxiliary fuel injector (3).

2. The asymmetric combustion chamber system of the high power density diesel engine as recited in claim 1, characterized in that an inward combustion chamber annular bulge (7) is provided in the middle of the side wall of said combustion chamber (6) to divide said combustion chamber (6) into a combustion chamber upper layer pit (8) and a combustion chamber lower layer pit (9);

the fuel spray beam sprayed by the main fuel sprayer (2) points to the annular bulge (7) of the combustion chamber, the tail end of the fuel spray beam (4) of the main fuel sprayer collides with the annular bulge (7) of the combustion chamber, is divided into two upward and downward plumes, and enters the upper-layer pit (8) and the lower-layer pit (9) of the combustion chamber in a wall surface jet flow mode.

3. The asymmetric combustion chamber system of the high-power-density diesel engine as claimed in claim 2, characterized in that the profile of the lower combustion chamber pit (9) is reduced to enhance the intensity of the swirl flow entering the lower combustion chamber pit (9), so that the swirl flow entering the lower combustion chamber pit (9) is greater than the swirl flow entering the upper combustion chamber pit (8) to promote the air-fuel mixture.

4. The asymmetric combustion chamber system of the high-power-density diesel engine as claimed in claim 3, characterized in that said combustion chamber annular protrusion (7) is of a circular arc structure, and said circular arc structure is respectively connected with the molded lines of said combustion chamber upper layer pit (8) and said combustion chamber lower layer pit (9).

5. The asymmetric combustion chamber system of the high power density diesel engine as recited in claim 4, characterized in that the fuel mist bundle (4) of the main fuel injector is directed to the middle point of the combustion chamber annular bulge (7).

6. The asymmetric combustion chamber system of a high power density diesel engine as claimed in any of claims 1-5, characterized in that said combustion chamber lower dimples (9) are arranged symmetrically along the central axis of said piston (13).

7. The asymmetric combustion chamber system of the diesel engine with high power density as recited in claim 6, characterized in that the main injector (2) has a plurality of injection holes uniformly distributed along the circumferential direction of the injection nozzle, the auxiliary injector (3) has a plurality of injection holes, and one injection hole of the main injector (2) is opposite to one injection hole of the auxiliary injector (3).

8. The asymmetric combustion chamber system of a high power density diesel engine as claimed in claim 7, characterized in that the number of the injection holes of said sub-injector (3) is singular, and the injection holes of said sub-injector (3) are symmetrically distributed with reference to the middle injection hole thereof.

9. An asymmetric combustion chamber system for a high power density diesel engine according to claim 8 characterized in that the fuel mist jet (5) of the secondary fuel injector is directed towards the centre of the combustion chamber (6).

Technical Field

The invention belongs to the technical field of diesel engines, and particularly relates to an asymmetric combustion chamber system suitable for a high-power-density diesel engine.

Background

In order to meet the requirement that the volume of a power cabin of a special vehicle (such as a tank) is continuously reduced, the strengthening degree of an engine is higher and higher, the power per liter index of the engine breaks through 100-110 kW/L, and the engine is developing towards the target of 120kW/L or higher. For safety and power reasons, the special engine is generally a diesel engine. Whereas diesel fuel is diffusion combustion dominated by spray mixing. To increase the power per liter of a diesel engine, the quantity and rate of fuel injected by the diesel engine are correspondingly increased. Therefore, a main oil injector and an auxiliary oil injector can be arranged in the cylinder, the main oil injector is vertically arranged in the center of the cylinder cover, the auxiliary oil injector is obliquely arranged on the outer side of the cylinder cover, the two oil injectors can simultaneously increase the overall oil injection rate, shorten the oil injection duration and meet the requirement of a high-power-density diesel engine on the oil injection rate.

However, fuel mist beams of the auxiliary fuel injector in the main and auxiliary fuel injection system are asymmetric about the central axis of the cylinder, so that the overall fuel distribution is asymmetric, the fuel on one side of the auxiliary fuel injector is more, and the fuel far away from the auxiliary fuel injector is less, so that the overall equivalence ratio distribution is uneven and asymmetric, and the combustion performance is influenced.

In summary, in the main and auxiliary fuel injection systems of the high-power-density diesel engine, the improvement of the nonuniformity and asymmetry of the equivalence ratio distribution is the key for optimizing the combustion performance of the diesel engine.

Disclosure of Invention

The invention provides an asymmetric combustion chamber system suitable for a high-power-density diesel engine, aiming at solving the technical problems of non-uniform and asymmetric distribution of an equivalent ratio caused by non-uniform and asymmetric distribution of fuel oil in a combustion chamber system in the prior art by adjusting the proportion of air quantity at one side of an auxiliary fuel injector and one side of the auxiliary fuel injector far away from the auxiliary fuel injector to be matched with the characteristics of more fuel oil at one side of the auxiliary fuel injector and less fuel oil at one side of the main fuel injector and the auxiliary fuel injector by enabling the volume of a first pit at one side of the auxiliary fuel injector of the combustion chamber to be larger than the volume of a second pit at one side of the auxiliary fuel injector far away from the auxiliary fuel injector by eccentrically arranging the combustion chamber and a piston.

To achieve the above object, according to one aspect of the present invention, there is provided an asymmetric combustion chamber system for a high power density diesel engine, comprising a combustion chamber provided in a piston, a main injector vertically provided in the center of a cylinder head, and a sub injector obliquely provided to the cylinder head,

the combustion chamber and the piston are arranged eccentrically, and the center of a throat of the combustion chamber is positioned on one side of the auxiliary fuel injector, so that the volume of a first pit of the combustion chamber on one side of the auxiliary fuel injector is larger than the volume of a second pit of the combustion chamber on one side far away from the auxiliary fuel injector.

Preferably, the middle part of the side wall of the combustion chamber is provided with an inward combustion chamber annular bulge so as to divide the combustion chamber into a combustion chamber upper-layer pit and a combustion chamber lower-layer pit;

the fuel oil mist beam sprayed by the main oil sprayer points to the annular bulge of the combustion chamber, the tail end of the fuel oil mist beam collides with the annular bulge of the combustion chamber, is divided into two upward and downward plumes, and enters the upper-layer pit and the lower-layer pit of the combustion chamber in a wall surface jet flow mode.

Preferably, the molded line of the lower pit of the combustion chamber is in a necking shape to enhance the swirl strength entering the lower pit of the combustion chamber, so that the swirl flow entering the lower pit of the combustion chamber is larger than the swirl flow entering the upper pit of the combustion chamber, and the oil-gas mixing is promoted.

Preferably, the annular bulge of the combustion chamber is of an arc structure, and the arc structure is respectively connected with molded lines of the upper pit layer and the lower pit layer of the combustion chamber.

Preferably, the fuel fog beam sprayed by the main fuel sprayer is directed to the middle point of the annular bulge of the combustion chamber.

Preferably, the combustion chamber lower dimples are arranged symmetrically along a central axis of the piston.

Preferably, the main injector is evenly distributed with a plurality of injection holes along the circumferential direction of the injection nozzle, the auxiliary injector is provided with a plurality of injection holes, and one injection hole of the main injector is opposite to one injection hole of the auxiliary injector.

Preferably, the number of the injection holes of the auxiliary injector is singular, and the injection holes of the auxiliary injector are symmetrically distributed with reference to the middle injection hole.

Preferably, the fuel mist of the secondary fuel injector is directed towards the center of the combustion chamber.

In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:

1. the invention provides an asymmetric combustion chamber system suitable for a high-power-density diesel engine, wherein a combustion chamber and a piston are eccentrically arranged, the center of a throat of the combustion chamber is positioned at one side of an auxiliary fuel injector, so that the volume of a first pit of the combustion chamber at one side of the auxiliary fuel injector is larger than the volume of a second pit at one side far away from the auxiliary fuel injector, the proportion of air quantity at one side of the auxiliary fuel injector and one side far away from the auxiliary fuel injector can be adjusted, the air quantity is matched with the characteristics that fuel at one side of the auxiliary fuel injector in a main fuel injector system is more and fuel at one side far away from the auxiliary fuel injector is less, and the problems of non-uniform and asymmetric distribution of an equivalence ratio caused by non-uniform and asymmetric distribution of fuel.

2. The invention provides an asymmetric combustion chamber system suitable for a high-power-density diesel engine, wherein an inward combustion chamber annular bulge is arranged in the middle of the side wall of a combustion chamber, the combustion chamber annular bulge divides a combustion chamber pit into a combustion chamber upper pit and a combustion chamber lower pit, the combustion chamber lower pit is a main combustion generation area, the molded line of the combustion chamber lower pit is in a necking shape, and the turbulence intensity in the combustion chamber lower pit can be enhanced; the tail end of the fuel oil mist bundle of the main oil sprayer collides with the annular bulge of the combustion chamber to form two upward and downward swirling flows which respectively enter the upper pit and the lower pit of the combustion chamber, so that oil-gas mixing is promoted, the air utilization rate is improved, and the combustion effect under the condition of low air-fuel ratio is improved.

3. The invention provides an asymmetric combustion chamber system suitable for a high-power-density diesel engine, which comprises a main oil sprayer and an auxiliary oil sprayer, wherein the main oil sprayer is vertically arranged in the center of a cylinder cover, the auxiliary oil sprayer is obliquely arranged on the outer side of the cylinder cover, the two oil sprayers can spray oil simultaneously to increase the overall oil spraying rate, shorten the oil spraying duration, and effectively solve the problem of insufficient oil spraying rate of a single oil sprayer in the high-power-density diesel engine.

Drawings

FIG. 1 is a schematic structural diagram of an asymmetric combustion chamber system suitable for use in a high power density diesel engine according to the present invention;

FIG. 2 is a schematic diagram showing the matching relationship between the fuel spray beam of the main oil sprayer and the annular bulge of the combustion chamber in the asymmetric combustion chamber system of the high-power-density diesel engine according to the invention;

FIG. 3 is a cross-sectional view of an asymmetric combustion chamber of the present invention in an asymmetric combustion chamber system for a high power density diesel engine;

FIG. 4 is a line contour diagram of the asymmetric region of an asymmetric combustion chamber in an asymmetric combustion chamber system suitable for use in a high power density diesel engine in accordance with the present invention;

FIG. 5 is a schematic diagram of the fuel spray distribution of the main and auxiliary fuel injectors in an asymmetric combustion chamber system suitable for use in a high power density diesel engine according to the present invention.

The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein: 1-a cylinder head; 2-main oil ejector; 3-auxiliary fuel injector; 4-fuel mist bundle of main fuel injector; 5-fuel mist bundle of the auxiliary fuel injector; 6-a combustion chamber; 7-a combustion chamber annular projection; 8-combustion chamber upper pit; 9-combustion chamber lower pit; 10-a first pit; 11-a second pit; 12-a cylinder; 13-piston.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Referring to fig. 1, the present invention provides an asymmetric combustion chamber system suitable for a high power density diesel engine, including a main oil injector 2, an auxiliary oil injector 3 and a combustion chamber 6, where the main oil injector 2 is vertically installed in the center of a cylinder head 1, the auxiliary oil injector 3 is installed at the outer side of the cylinder head 1 in an inclined manner, and the main oil injector 2 and the auxiliary oil injector 3 inject oil simultaneously, so as to increase the overall oil injection rate, shorten the oil injection duration, and effectively solve the problem of insufficient oil injection rate of a single oil injector in the high power density diesel engine. However, in the combustion chamber system, the fuel mist of the sub-injector 3 is asymmetrical with respect to the central axis of the cylinder 12, so that the overall fuel distribution is also asymmetrical, the side of the sub-injector 3 has more fuel, and the side far from the sub-injector 3 has less fuel, thereby causing the overall equivalence ratio distribution to be uneven and asymmetrical, and affecting the combustion performance. Therefore, the invention provides an asymmetric combustion chamber structure, by arranging an inward combustion chamber annular bulge 7 in the middle of the side wall of the combustion chamber 6, the tail end of the fuel spray beam 4 of the main fuel injector collides with the combustion chamber annular bulge 7 to form double swirl, and the double swirl is fully mixed with the air in the combustion chamber 6; through proper asymmetric design, the ratio of the air amount on one side of the auxiliary fuel injector 3 and the air amount on one side far away from the auxiliary fuel injector 3 is adjusted to be matched with the characteristics that the fuel amount on one side of the auxiliary fuel injector 3 is more and the combustion amount on one side far away from the auxiliary fuel injector 3 is less, so that the problems of uneven distribution and asymmetry of the equivalent ratio caused by uneven and asymmetric fuel distribution of a high-power-density diesel engine are solved.

Specifically, as shown in fig. 1, in the embodiment of the present invention, the asymmetric combustion chamber system includes a main injector 2, a secondary injector 3, and a combustion chamber 6, where the main injector 2 and the secondary injector 3 are both disposed on a cylinder head 1, and both inject directly in the cylinder, and share one combustion chamber 6.

Further, the main fuel injector 2 is vertically mounted on the cylinder head 1, and the central axis thereof coincides with the central axis of the cylinder 12, and the auxiliary fuel injector 3 is obliquely mounted on the cylinder head 1, and the central axis thereof is on the same plane with the central axis of the cylinder 12. An included angle between the central axis of the auxiliary fuel injector 3 and the central axis of the cylinder 12 is alpha, an intersection point of the central axis of the auxiliary fuel injector 3 and the bottom surface of the cylinder cover 1 is A, a radial distance between the intersection point A and the central axis of the main fuel injector 2 is L, and the included angle alpha and the radial distance L are specifically determined according to a target model.

As a preferred embodiment of the present invention, the reference values of the included angle α and the radial distance L are 25 ° and 36mm, respectively.

To explain further, as shown in fig. 5, the central axis of the main injector 2 and the central axis of the auxiliary injector 3 extend to form a plane S, the central axis of one injection hole of the main injector 2 is located on the plane S and points to the side of the auxiliary injector 3, the number of injection holes of the auxiliary injector 3 is generally singular, and the central axis of the middle injection hole is also located on the plane S, and the injection holes of the auxiliary injector 3 are symmetrically arranged with reference to the middle injection hole; the main oil injector 2 bears the main oil injection quantity, the auxiliary oil injector 3 plays a role in auxiliary oil injection, but the fuel oil mist bundle 5 of the auxiliary oil injector is mainly distributed in the combustion chamber on one side of the auxiliary oil injector 3, so that more fuel oil is arranged on one side of the auxiliary oil injector 3, and less fuel oil is arranged on one side far away from the auxiliary oil injector 3.

As a preferred embodiment of the present invention, the reference value of the number of injection holes of the main injector 2 is 8; the reference value of the number of the oil injection holes of the auxiliary oil injector 3 is 3, and the reference value of the included angle between the left and right oil injection holes of the auxiliary oil injector 3 and the middle oil injection hole thereof is 47 degrees.

As a further preferable embodiment of the present invention, the reference value of the ratio of the injection quantity of the main injector 2 to the injection quantity of the sub-injector 3 is 8: 2, it is understood that the fuel injection amount ratio of the side of the combustion chamber 6 closer to the sub-injector 3 to the side farther from the sub-injector 3 is 3:2, and therefore the fuel distribution in the combustion chamber 6 is uneven and asymmetric.

In order to solve the problems of non-uniform and non-symmetric equivalence ratio distribution caused by non-uniform and asymmetric fuel distribution, the embodiment of the invention provides an asymmetric combustion chamber structure, which comprises the following specific parts:

as shown in fig. 1-3, an inward combustion chamber annular protrusion 7 is arranged in the middle of the side wall of the combustion chamber 6, the combustion chamber annular protrusion 7 divides the combustion chamber 6 into a combustion chamber upper layer pit 8 and a combustion chamber lower layer pit 9, the combustion chamber annular protrusion 7 is an arc structure with a radius of r, and the arc structure is respectively connected with molded lines of the combustion chamber upper layer pit 8 and the combustion chamber lower layer pit 9 to play a role in transition.

In a further description, the combustion chamber lower pit 9 is a main area where combustion occurs, and the profile of the combustion chamber lower pit 9 is in a necking shape, so that the turbulence intensity in the combustion chamber lower pit 9 is enhanced, and mixing and combustion are promoted. The fuel spray beam 4 of the main oil sprayer points to the annular bulge 7 of the combustion chamber, namely the middle point of the circular arc structure, the tail end of the fuel spray beam 4 of the main oil sprayer collides with the annular bulge 7 of the combustion chamber to form two upward and downward plumes, and the plumes enter the upper pit 8 and the lower pit 9 of the combustion chamber respectively in the wall surface jet flow movement mode, wherein the wall surface jet flow entering the lower pit 9 of the combustion chamber downwards is dominant.

As a preferred embodiment of the present invention, the radius r of the circular arc structure is 1 mm.

To explain further, as shown in fig. 3, the center of the throat of the combustion chamber 6 is O ', the center O' is not on the central axis of the cylinder 12, the center O 'is on the same plane with the central axis of the cylinder 12 and the central axis of the sub-injector 3, the center O' is located on the side of the sub-injector 3 and is at a distance S from the central axis of the cylinder 12, and as a result, the combustion chamber 6 has a larger first dimple volume 10 on the side of the sub-injector 3 and a smaller second dimple volume 11 on the side away from the sub-injector 3. Accordingly, the amount of air of the combustion chamber 6 on the side of the auxiliary fuel injector 3 is larger, and the proportion of the amount of air of the combustion chamber 6 on the side of the auxiliary fuel injector 3 and on the side far away from the auxiliary fuel injector 3 can be controlled by adjusting the magnitude of the eccentric distance S, so that the proportion is matched with the characteristic that the fuel on the side of the auxiliary fuel injector 3 is larger and the fuel on the side far away from the auxiliary fuel injector 3 is smaller in the asymmetric combustion chamber system, and the problem of uneven and asymmetric distribution of the equivalence ratio caused by uneven and asymmetric distribution of the fuel in the combustion chamber system is solved. After the centre O' of the throat of the combustion chamber 6 is eccentrically arranged, the asymmetrical surface of the throat of the combustion chamber 6 needs continuous smooth transition, and the contour line schematic diagram is shown in fig. 4.

Further, as shown in fig. 3, a thin solid line shows a symmetric throat profile, a center O of which is located on the central axis of the cylinder 12, and as shown in fig. 3, a solid line shows an asymmetric throat profile, a center O 'of which is not located on the central axis of the cylinder 12, and a distance between the center O and the center O' is S, it can be seen by comparing the two, compared with the symmetric throat profile, a first pit volume 10 of the asymmetric throat profile on one side of the sub-injector 3 is larger, and a second pit volume 11 of the asymmetric throat profile on one side far away from the sub-injector 3 is smaller.

To be more specific, as shown in fig. 3 and 4, the contour line of the throat where the point F (F ') is located is a circle with the center of the circle being O ', the contour line of the throat where the point C (C ') is located is a circle with the center of the circle being O_C，O_CAnd O are on the same vertical line, coinciding with the central axis of the cylinder 12; the contour lines of the horizontal section at any height between F (F ') and C (C') are all circles with the center positions (such as O shown in FIG. 3)_DAnd O_E) Are all located at O' -O_COn a straight line as shown.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.