Combustion chamber of a turbulent natural gas engine

Abstract

The present invention discloses a combustion chamber of a turbulent natural gas engine, which is arranged on the top of a piston, a brake exhaust valve clearance pit of a cylinder is arranged on the annular area on the top of the piston, a proximal inlet duct bottom hole chamfer and a distal inlet duct bottom hole chamfer are arranged on the top of the cylinder, and the combustion chamber includes at least two turbulent chute grooves, which are arranged on the annular area, each turbulent chute runs through the annular area, and the transverse cross section of the turbulent chute is L-shaped. The arrangement of the turbulent chute of the combustion chamber of the present invention can increase the turbulent kinetic energy in the annular area of ​​the piston top surface.

Description

Technical Field

[0001] The invention relates to the field of natural gas engines, in particular to a combustion chamber of a turbulent natural gas engine with a spiral air passage. Background Art

[0002] The combustion chamber structure of a natural gas engine has a significant impact on the turbulence intensity in the cylinder. Optimizing the shape of the combustion chamber, increasing the turbulence intensity in the cylinder, and improving the flame propagation speed are of great significance to improving the power and economy of the natural gas engine.

[0003] At present, most of the commercial natural gas engines are developed from diesel engines. Natural gas engines use the original diesel engine's volute airway, and the airway performance is mainly vortex, supplemented by tumble. The combustion chamber of the natural gas engine cannot be directly used in the diesel engine. After redesign, the combustion chamber of the natural gas engine is generally straight or micro-shrink. The top surface of the piston of the natural gas engine is generally designed with a valve clearance pit corresponding to the brake exhaust valve 1 (i.e., the brake exhaust valve clearance pit, see Figure 1 ), and there are no other features on the top surface of the piston. In the existing scheme, after the piston is equipped with a spiral intake port, at the end of compression, the airflow forms a large-scale vortex with orderly movement in the cylinder. On the top surface of the piston, especially in the annular area near the intake port, the airflow cannot be broken into small-scale vortices due to the lack of obstruction or guidance, resulting in the turbulent kinetic energy in the annular area on the top surface of the piston being much lower than the turbulent kinetic energy in the combustion chamber pit. When the flame propagates from the center of the combustion chamber to the distal area, the flame propagation speed slows down, that is, the flame propagation speed in the later stage of combustion is lower than the flame propagation speed in the early stage of combustion, resulting in a decrease in thermal efficiency. At the same time, the probability of spontaneous combustion of the distal mixture is increased, resulting in a narrowing of the detonation boundary.

[0004] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0005] The object of the present invention is to provide a combustion chamber of a turbulent natural gas engine, the arrangement of which turbulent chute can well overcome the above-mentioned defects of the combustion chamber in the prior art.

[0006] To achieve the above-mentioned purpose, the present invention provides a combustion chamber of a spoiler-type natural gas engine, which is arranged on the top of a piston, and a brake exhaust valve give-way pit of the cylinder is arranged on the annular area on the top of the piston, and a proximal inlet duct bottom hole chamfer and a distal inlet duct bottom hole chamfer are arranged on the top of the cylinder. The combustion chamber includes at least two spoiler chute grooves, which are arranged on the annular area, each spoiler chute runs through the annular area, and the transverse cross-section of the spoiler chute is L-shaped.

[0007] In a preferred embodiment, one of the at least two spoiler chute is located below between the chamfer of the bottom hole of the proximal air inlet duct and the chamfer of the bottom hole of the distal air inlet duct, and the other is located below one side of the chamfer of the bottom hole of the distal air inlet duct.

[0008] In a preferred embodiment, the spoiler chute has a long side and a short side when viewed from the top of the piston, the short side is parallel to the center line of an annular region, and the distance between the short side and the center line of the annular region parallel to it is between 4 and 6 mm.

[0009] In a preferred embodiment, the angle between the short side and the vertical center line of the annular area is between 20° and 30°.

[0010] In a preferred embodiment, the angle between the short sides of at least two spoiler chute grooves is between 90° and 100°.

[0011] In a preferred embodiment, the total length of the spoiler chute in top view is between 22 and 24 mm.

[0012] In a preferred embodiment, the angle between the L-shaped short side of the transverse cross section of the spoiler chute and the center line of the piston in the vertical direction is between 25 and 35 degrees.

[0013] In a preferred embodiment, a rounded transition is formed between the L-shaped short side and the L-shaped long side of the transverse cross section of the spoiler chute.

[0014] In a preferred embodiment, the maximum depth of the spoiler chute from the top surface of the piston is between 2 and 3 mm.

[0015] Compared with the prior art, the combustion chamber of the turbulent natural gas engine of the present invention has the following beneficial effects: the present solution provides a turbulent chute on the annular area at the top of the combustion chamber, which can increase the turbulent kinetic energy in the annular area on the top surface of the piston. At the same time, it accelerates the flame propagation speed in the late stage of combustion and improves thermal efficiency. It further reduces the probability of spontaneous combustion of the far-end mixed gas and widens the detonation boundary. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a three-dimensional schematic diagram of a piston top surface according to an embodiment of the prior art;

[0017] Figure 2 is a three-dimensional schematic diagram of a piston top surface according to an embodiment of the present invention;

[0018] Figure 3 is a schematic top view of a piston top surface according to an embodiment of the present invention;

[0019] Figure 4 yes Figure 3 A schematic partial cross-sectional view at B-B of FIG.

[0020] Description of main reference numerals:

[0021] 1-brake exhaust valve give way pit, 2-near-end intake duct bottom hole chamfer, 3-distal intake duct bottom hole chamfer, 4-spoiler chute, 5-annular area. DETAILED DESCRIPTION

[0022] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0023] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0024] like Figures 2 to 4 As shown, a combustion chamber of a turbulent natural gas engine according to a preferred embodiment of the present invention is arranged on the top of the piston. The top of the piston has an annular area 5, on which a brake exhaust valve give-way pit 1 of the cylinder is arranged. The top of the cylinder is also provided with a proximal intake duct bottom hole chamfer 2 and a distal intake duct bottom hole chamfer 3. The combustion chamber includes at least two turbulent chute 4, which are arranged on the annular area 5. Each turbulent chute 4 passes through the annular area 5, and the transverse cross-section of the turbulent chute 4 is L-shaped. This embodiment only shows two, but the present invention is not limited thereto. The number of turbulent chute 4 is generally determined by the number of intake ducts, but it does not necessarily have to be the same as the number of intake ducts. For example, when the number of intake ducts is two, the number of turbulent chute 4 can be greater than two if the arrangement conditions of the annular area 5 allow.

[0025] See also Figure 2 and Figure 3 In some embodiments, one of the at least two spoiler chute grooves 4 is located below the chamfer 2 of the bottom hole of the proximal air inlet duct and the chamfer 3 of the bottom hole of the distal air inlet duct, and the other is located below one side of the chamfer 3 of the bottom hole of the distal air inlet duct. The spoiler chute 4 has a long side and a short side when viewed from the top of the piston. The short side is parallel to the center line of an annular area 5, and the distance L1 between the short side and the center line of the annular area 5 parallel to it is about 4 to 6 mm. The angle A2 between the short side and the center line of the annular area 5 in the vertical direction is between 20 and 30°. The angle A1 between the short sides of at least two spoiler chute grooves 4 is between 90 and 100°. The total length L2 of the spoiler chute 4 when viewed from above is about 22 to 24 mm.

[0026] See also Figure 4In some embodiments, the angle A3 between the short side of the L-shaped shape of the transverse section of the spoiler chute 4 and the center line of the piston in the vertical direction is between 25 and 35 degrees. The short side of the L-shaped shape of the transverse section of the spoiler chute 4 and the long side of the L-shaped shape are rounded transitions, and the radius R of the transition rounded corner is between about 0.5 and 1 mm. The maximum depth H of the spoiler chute 4 from the top surface of the piston is between about 2 and 3 mm, but generally H does not exceed 3 mm.

[0027] In some embodiments, the top view shape and cross-sectional shape of the spoiler chute 4 of this embodiment are substantially identical, and the position between the two spoiler chute 4 is mainly determined by the angle between the short sides of the two spoiler chute 4. However, when the number of spoiler chute 4 is greater than two, the distances between the spoiler chute 4 may be unequal, and the total length L2 may also be unequal. Preferably, the total length L2 of the spoiler chute 4 remains equal, and the distances between the spoiler chute 4 are equal.

[0028] In summary, the combustion chamber of the turbulent natural gas engine of the present invention has the following advantages: the present solution provides a turbulent chute on the annular area at the top of the combustion chamber, and the turbulent chute can increase the turbulent kinetic energy in the annular area on the top surface of the piston. At the same time, it accelerates the flame propagation speed in the late stage of combustion and improves thermal efficiency. In addition, it reduces the probability of spontaneous combustion of the far-end mixed gas and widens the detonation boundary.

[0029] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A combustion chamber of a turbulent natural gas engine, which is arranged on the top of a piston, a brake exhaust valve clearance pit of a cylinder is arranged on the annular area on the top of the piston, and a proximal inlet duct bottom hole chamfer and a distal inlet duct bottom hole chamfer are arranged on the top of the cylinder, characterized in that: The combustion chamber comprises at least two spoiler chute grooves, which are arranged on the annular area, each of the spoiler chute grooves passes through the annular area, and the transverse cross section of the spoiler chute groove is L-shaped; One of the at least two spoiler chute grooves is located below between the chamfer of the bottom hole of the proximal air inlet duct and the chamfer of the bottom hole of the distal air inlet duct, and the other is located below one side of the chamfer of the bottom hole of the distal air inlet duct; The spoiler chute has a long side and a short side when viewed from the top of the piston, the short side is parallel to a center line of the annular region, and the distance between the short side and the center line of the annular region to which it is parallel is between 4 and 6 mm; The angle between the short side and the vertical center line of the annular area is between 20° and 30°; The angle between the short sides of the at least two spoiler chute is between 90° and 100°; The total length of the spoiler chute when viewed from above is between 22 and 24 mm; The long side and the short side of the top view of the spoiler chute do not intersect at the outer edge of the annular area of ​​the top of the piston; The number of the at least two spoiler chute grooves is greater than the number of the air intake passages at the top of the cylinder, and when the number of the spoiler chute grooves is greater than two, the distances between the spoiler chute grooves are not equal.

2. The combustion chamber of the turbulent natural gas engine according to claim 1, characterized in that: The included angle between the L-shaped short side of the transverse cross section of the spoiler chute and the center line of the piston in the vertical direction is between 25 and 35 degrees.

3. The combustion chamber of the turbulent natural gas engine according to claim 2, characterized in that: The L-shaped short side and the L-shaped long side of the transverse cross section of the spoiler chute are transitioned with a rounded corner.

4. The combustion chamber of the turbulent natural gas engine according to claim 1, characterized in that: The maximum depth of the spoiler chute from the top surface of the piston is between 2 and 3 mm.

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