Natural gas engine combustion system

Abstract

The invention relates to the technical field of natural gas engines, and particularly discloses a natural gas engine combustion system which is characterized in that after gas in a body part of a pre-combustion chamber is ignited, high-temperature gas is gathered and pressed into a gathering channel through a gas gathering part to be pressurized and mixed, and then the high-temperature gas is sprayed out of a plurality of spraying holes to a main combustion chamber to be ignited; the inner diameter of the gas gathering part is gradually reduced in the gas flowing direction to form a gradually-contracted flow channel, the gradual gathering effect on high-temperature gas is achieved, downward flowing of gas flow is accelerated, the flowing dead zone during gas inlet is reduced, the high-temperature gas flow can be guided to be directionally spread towards a main combustion chamber, jet flow multi-point ignition is achieved, and the combustion efficiency is improved. And the non-uniformity of flame spreading in all directions in the pre-combustion chamber after ignition is eliminated, flame jet flow is accelerated to enter the main combustion chamber, rapid release of energy is achieved, the combustion duration time of the main combustion chamber is shortened, the heat efficiency is improved, oil consumption is effectively reduced, the undesirable phenomena such as knocking are restrained, and the overall performance of the engine is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas engines, and in particular to a natural gas engine combustion system. Background Art

[0002] As the environmental pollution and climate change problems caused by traditional fuel engines become increasingly serious, and with the growing global demand for clean energy and reduced carbon emissions, natural gas, as a fossil fuel with abundant reserves and clean combustion (its carbon dioxide emissions are 20-30% lower than gasoline and there is almost no particulate matter emissions), has become an important choice for automotive fuel.

[0003] Existing natural gas engine combustion systems primarily rely on spark plug ignition, resulting in a small initial fire core and slow combustion, significantly limiting improvements in natural gas engine thermal efficiency. To improve the thermal efficiency of natural gas engines, a pre-combustion chamber is typically introduced alongside the main combustion chamber to accelerate combustion. However, existing pre-combustion chambers are prone to uneven high-temperature gas ejection from various injection holes, hindering the combustion process. Furthermore, uneven jet flow can lead to uneven gas distribution at the end of the main combustion chamber, potentially causing localized hot spots that can induce detonation and increase pressure fluctuations within the engine, impacting overall engine performance and lifespan.

[0004] Therefore, there is an urgent need for a natural gas engine combustion system to solve the above problems. Summary of the Invention

[0005] The object of the present invention is to provide a natural gas engine combustion system that can improve combustion efficiency, suppress the occurrence of knock, and effectively reduce fuel consumption.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a natural gas engine combustion system, comprising:

[0008] main combustion chamber;

[0009] A preburner, the preburner includes a converging channel and a precombustion chamber, the cross-sectional area of the converging channel is smaller than the cross-sectional area of the precombustion chamber, and the two ends of the converging channel along its own length direction are respectively an air inlet end and an air outlet end, the air outlet end is circumferentially provided with a plurality of injection holes, and the plurality of injection holes are all connected to the main combustion chamber, the precombustion chamber includes a main body and a gas gathering part, the inner diameter of the gas gathering part gradually decreases along the gas flow direction, and the gas gathering part is connected between the main body and the air inlet end.

[0010] As an optimal technical solution for the above-mentioned natural gas engine combustion system, the bottom wall of the main combustion chamber is provided with a protrusion and an annular groove, the protrusion is located in the center of the bottom of the main combustion chamber, the annular groove surrounds the protrusion in the circumferential direction, and the plurality of injection holes are arranged corresponding to the annular groove.

[0011] As an optimal technical solution for the above-mentioned natural gas engine combustion system, the natural gas engine combustion system also includes a plurality of guide vanes, which are arranged in a one-to-one correspondence with the plurality of injection holes, and the guide vanes are used to guide the gas at the injection holes to be sprayed to the bottom of the annular groove.

[0012] As a preferred technical solution of the above-mentioned natural gas engine combustion system, the longitudinal cross-section of the main combustion chamber is W-shaped.

[0013] As a preferred technical solution of the above-mentioned natural gas engine combustion system, the multiple injection holes are located at the same height, and on the longitudinal section in the axial direction of the preburner, the angle range of the cone angle formed by the multiple injection holes injecting gas is 140°-170°.

[0014] As a preferred technical solution of the above-mentioned natural gas engine combustion system, on the radial cross section of the preburner, the deflection angle formed by the gas injection from each injection hole ranges from 10° to 45°.

[0015] As a preferred technical solution of the above-mentioned natural gas engine combustion system, the diameter of the main body is d1, and the diameter of the converging channel is d2, wherein d1 and d2 satisfy: 1.5≤d1 / d2≤2.5.

[0016] As a preferred technical solution of the above-mentioned natural gas engine combustion system, the height of the main body is h1, and the height of the converging channel is h2, wherein h1 and h2 satisfy: 2≤h2 / h1≤4.

[0017] As a preferred technical solution of the above-mentioned natural gas engine combustion system, the gas gathering portion is in an inverted cone shape, and the inverted cone angle of the gas gathering portion ranges from 60° to 100°.

[0018] As a preferred technical solution of the above-mentioned natural gas engine combustion system, the plurality of injection holes are spaced apart and evenly arranged at the gas outlet end along the circumferential direction.

[0019] The beneficial effects of the present invention are:

[0020] The present invention provides a natural gas engine combustion system, which includes: a main combustion chamber and a preburner, the preburner includes a converging channel and a preburner, the cross-sectional area of the converging channel is smaller than the cross-sectional area of the preburner, and the two ends of the converging channel along its own length direction are respectively an air inlet end and an air outlet end, the air outlet end is provided with a plurality of injection holes along the circumference, and the plurality of injection holes are all connected to the main combustion chamber, the preburner includes a main body and a gas gathering part, the inner diameter of the gas gathering part gradually decreases along the gas flow direction, and the gas gathering part is connected between the main body and the air inlet end. With such arrangement, after the gas in the main body of the pre-combustion chamber is ignited, the high-temperature gas is gathered through the gas gathering part and pressed into the converging channel for pressurization and mixing, and then ejected from multiple injection holes to the main combustion chamber for ignition. Among them, the inner diameter of the gas gathering part gradually decreases along the gas flow direction to form a tapered flow channel, which gradually gathers the high-temperature gas to form high-intensity turbulence, accelerates the downward flow of the airflow, and reduces the flow dead zone during intake. It can further guide the high-temperature airflow to the directional propagation of the main combustion chamber, realize multi-point ignition of the jet, and eliminate the uneven propagation of the flame in all directions in the pre-combustion chamber after ignition. It accelerates the flame jet into the main combustion chamber, realizes the rapid release of energy, shortens the combustion duration of the main combustion chamber, improves thermal efficiency, effectively reduces fuel consumption, and suppresses adverse phenomena such as detonation, thereby improving the overall performance and service life of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic structural diagram of the natural gas engine combustion system provided by the present invention;

[0022] Figure 2 The structure of the pre-burner provided by the present invention is schematically shown Figure 1 ;

[0023] Figure 3 The structure of the pre-burner provided by the present invention is schematically shown Figure 2 .

[0024] in:

[0025] 1. Main combustion chamber;

[0026] 2. Preburner; 21. Converging channel; 22. Precombustion chamber;

[0027] 3. Injection hole; 4. Raised portion; 5. Annular groove. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but are not to be construed as limiting the present invention.

[0029] In the description of the present invention, it should be noted that the terms "center," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0030] Unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed or removable connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0031] Unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0032] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0033] like Figures 1 to 3As shown, this embodiment provides a natural gas engine combustion system, which includes: a main combustion chamber 1 and a preburner 2, the preburner 2 includes a converging channel 21 and a precombustion chamber 22, the cross-sectional area of the converging channel 21 is smaller than the cross-sectional area of the precombustion chamber 22, and the two ends of the converging channel 21 along its own length direction are respectively an air inlet end and an air outlet end, and the air outlet end is provided with a plurality of injection holes 3 along the circumferential direction, and the plurality of injection holes 3 are all connected to the main combustion chamber 1, and the precombustion chamber 22 includes a main body and a gas gathering part, the inner diameter of the gas gathering part gradually decreases along the gas flow direction, and the gas gathering part is connected between the main body and the air inlet end. With such arrangement, after the gas in the main body of the pre-combustion chamber 22 is ignited, the high-temperature gas is gathered through the gas gathering part and pressed into the converging channel 21 for pressurization and mixing, and then ejected from multiple injection holes 3 to the main combustion chamber for ignition. Among them, the inner diameter of the gas gathering part gradually decreases along the gas flow direction to form a tapered flow channel, which gradually gathers the high-temperature gas to form high-intensity turbulence, accelerates the downward flow of the airflow, and reduces the flow dead zone during intake. It can further guide the high-temperature airflow to the directional propagation of the main combustion chamber 1, realize multi-point ignition of the jet, and eliminate the uneven propagation of the flame in all directions in the pre-combustion chamber 22 after ignition. It accelerates the flame jet to enter the main combustion chamber 1, realizes the rapid release of energy, shortens the combustion duration of the main combustion chamber 1, improves thermal efficiency, effectively reduces fuel consumption, and suppresses adverse phenomena such as detonation, thereby improving the overall performance and service life of the engine.

[0034] Optionally, the bottom wall of the main combustion chamber 1 is provided with a protrusion 4 and an annular groove 5. The protrusion 4 is located at the bottom center of the main combustion chamber 1, and the annular groove 5 surrounds the protrusion 4 in the circumferential direction. A plurality of injection holes 3 are provided corresponding to the annular groove 5. Specifically, the longitudinal section of the main combustion chamber 1 is W-shaped. With such a configuration, the combination of the annular groove 5 and the protrusion 4 can guide the high-temperature gas to form a strong swirl and turbulence, so that the fuel and the oxidant are fully mixed, thereby improving the combustion efficiency. At the same time, the protrusion 4 blocks the high-temperature airflow from directly impacting the center of the bottom wall, and the annular groove 5 disperses the heat flow, avoids local overheating, and realizes uniform heat distribution. The W-shaped wavy cross-section also has higher rigidity, which can further resist the high-pressure deformation of the main combustion chamber 1.

[0035] Optionally, in order to further achieve precise matching between the injection hole 3 and the annular groove 5, the natural gas engine combustion system also includes multiple guide vanes, which are arranged in a one-to-one correspondence with the multiple injection holes 3, and the guide vanes are used to guide the gas at the injection hole 3 to be sprayed to the bottom of the annular groove 5.

[0036] Optionally, the multiple injection holes 3 are located at the same height, and in a longitudinal cross-section of the preburner 2 in the axial direction, the cone angle formed by the gas injection from the multiple injection holes 3 ranges from 140° to 170°. It should be noted that since the bottom of the pre-combustion chamber 22 protrudes from the bottom plane of the cylinder head by only a few millimeters, the difference in distribution at different heights is not significant. Generally, when multiple injection holes 3 are located at the same height, a too large cone angle will cause hot gas to rush toward the cylinder head, increasing the heat load. A too small cone angle will result in initial combustion being confined to the middle of the main combustion chamber 1, which is not conducive to the rapid propagation of the flame airflow.

[0037] Optionally, in order to form a vortex flow in the pre-combustion chamber 22, facilitate the gas renewal in the pre-combustion chamber 22, increase the turbulent kinetic energy and flow velocity, and thus improve the ignition conditions, on the radial cross section of the pre-burner 2, the angle range of the deflection angle formed by the gas injection from each injection hole 3 is 10°-45°.

[0038] In this embodiment, the cross-sectional shape of the injection hole 3 is circular, and the number of the injection holes 3 can be designed to be 8. The multiple injection holes 3 cooperate with each other to have a higher injection coverage range in the main combustion chamber 1, shortening the combustion duration.

[0039] Optionally, the diameter of the main body is d1, and the diameter of the converging channel 21 is d2, wherein d1 and d2 satisfy: 1.5≤d1 / d2≤2.5.

[0040] Optionally, the height of the main body is h1, and the height of the converging channel 21 is h2, wherein h1 and h2 satisfy: 2≤h2 / h1≤4.

[0041] Optionally, the gas gathering portion is in an inverted cone shape, and the inverted cone angle of the gas gathering portion ranges from 60° to 100°.

[0042] Optionally, the plurality of injection holes 3 are spaced apart and evenly arranged at the gas outlet end along the circumferential direction.

[0043] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A natural gas engine combustion system, characterized in that: include: Main combustion chamber (1); A preburner (2) includes a converging channel (21) and a pre-combustion chamber (22), wherein the cross-sectional area of the converging channel (21) is smaller than the cross-sectional area of the pre-combustion chamber (22), and the converging channel (21) has an air inlet end and an air outlet end at both ends along its length direction, and the air outlet end is provided with a plurality of injection holes (3) along the circumference, and the plurality of injection holes (3) are all connected to the main combustion chamber (1), and the pre-combustion chamber (22) includes a main body and an air gathering part, the inner diameter of the air gathering part gradually decreases along the gas flow direction, and the air gathering part is connected between the main body and the air inlet end.

2. The natural gas engine combustion system according to claim 1, characterized in that: The bottom wall of the main combustion chamber (1) is provided with a protrusion (4) and an annular groove (5), the protrusion (4) is located at the center of the bottom of the main combustion chamber (1), the annular groove (5) surrounds the protrusion (4) in a circumferential direction, and a plurality of injection holes (3) and the annular groove (5) are arranged correspondingly.

3. The natural gas engine combustion system according to claim 2, characterized in that: The natural gas engine combustion system further comprises a plurality of guide vanes, wherein the plurality of guide vanes are arranged in a one-to-one correspondence with the plurality of injection holes (3), and the guide vanes are used to guide the gas at the injection holes (3) to be sprayed to the bottom of the annular groove (5).

4. The natural gas engine combustion system according to claim 2, characterized in that: The longitudinal section of the main combustion chamber (1) is W-shaped.

5. The natural gas engine combustion system according to any one of claims 1 to 4, characterized in that: The plurality of injection holes (3) are located at the same height, and on the longitudinal section in the axial direction of the preburner (2), the cone angle formed by the injection of gas by the plurality of injection holes (3) is in the range of 140°-170°.

6. The natural gas engine combustion system according to claim 5, characterized in that: On a radial cross section of the preburner (2), the deflection angle formed by the gas injection from each injection hole (3) ranges from 10° to 45°.

7. The natural gas engine combustion system according to any one of claims 1 to 4, characterized in that: The diameter of the main body is d1, and the diameter of the converging channel (21) is d2, wherein d1 and d2 satisfy: 1.5≤d1 / d2≤2.

5.

8. The natural gas engine combustion system according to any one of claims 1 to 4, characterized in that: The height of the main body is h1, and the height of the converging channel (21) is h2, wherein h1 and h2 satisfy: 2≤h2 / h1≤4.

9. The natural gas engine combustion system according to any one of claims 1 to 4, characterized in that: The gas gathering portion is in an inverted cone shape, and the inverted cone angle of the gas gathering portion ranges from 60° to 100°.

10. The natural gas engine combustion system according to any one of claims 1 to 4, characterized in that: The plurality of injection holes (3) are spaced apart in the circumferential direction and evenly arranged at the gas outlet end.

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