Pre-combustion chamber and gas engine

Abstract

The invention relates to the technical field of engines, and provides a pre-combustion chamber and a gas engine, the pre-combustion chamber comprises a pre-combustion chamber body, the pre-combustion chamber body is provided with a pre-combustion cavity and a plurality of spraying holes, the multiple spraying holes are formed around the axis of the pre-combustion cavity at intervals, the spraying holes are gradually-expanded holes, and the spraying holes are communicated with the pre-combustion cavity. The small-diameter end of the spray hole is communicated with the pre-combustion cavity, and the large-diameter end of the spray hole is suitable for being communicated with a main combustion cavity of an engine. The pre-combustion chamber can improve the ignition stability under the working conditions of cold start and low load; meanwhile, after the pre-combustion chamber is ignited, the gradually-expanded spray holes are beneficial to increasing the ignition area of the high-energy particle jet flow in the main combustion chamber, the problem that the spray holes are choked under the supersonic jet flow condition is avoided, the combustion speed is increased, and the risks of cyclic change and knocking are reduced.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and more particularly to a pre-combustion chamber and a gas engine. Background Technology

[0002] Traditional spark plug ignition engines are limited by slow flame propagation speed, especially under low-speed, high-load conditions. This leads to combustion phase lag and low thermal efficiency, making it difficult to achieve efficient and stable combustion across a wide operating range. In particular, under lean-burn conditions, misfires or knocking are prone to occur. Furthermore, incomplete combustion increases emissions of pollutants such as CO and NOx, which is detrimental to environmental protection.

[0003] To address this, the relevant technology employs pre-combustion chamber jet ignition, which generates a high-speed jet flame in the pre-combustion chamber to ignite the air-fuel mixture in the main combustion chamber. This technology enables multi-point ignition, enhanced turbulence, and accelerated combustion in the main combustion chamber, overcoming the efficiency bottleneck of traditional spark plug ignition. Experiments show that the jet flame velocity can reach more than 15 times that of traditional flame propagation, and the combustion delay period is shortened by 40%-70%. This staged combustion mechanism overcomes the physical limitations of single-flame propagation, providing a new pathway for high thermal efficiency combustion.

[0004] Through high-energy jet ignition and rapid combustion, the relevant technologies employ low-tumble gas passages and pre-combustion chambers, achieving an ultra-high thermal efficiency of nearly 50% in lean-burn mode. However, existing pre-combustion chambers suffer from poor ignition stability under cold start and low-load conditions. Summary of the Invention

[0005] This invention provides a pre-combustion chamber and a gas engine to solve the problem of poor ignition stability of pre-combustion chambers under cold start and low load conditions in the prior art.

[0006] This invention provides a pre-combustion chamber, comprising: The pre-combustion chamber body is provided with a pre-combustion cavity and multiple nozzles. The multiple nozzles are arranged at intervals around the axis of the pre-combustion cavity. The nozzles are gradually expanding holes. The small diameter end of the nozzle is connected to the pre-combustion cavity, and the large diameter end of the nozzle is adapted to be connected to the main combustion cavity of the engine.

[0007] According to the present invention, a pre-combustion chamber is provided in which a plurality of spray holes are uniformly arranged around the axis of the pre-combustion chamber; Alternatively, the plurality of nozzles may include a plurality of first nozzles and a plurality of second nozzles, the plurality of first nozzles and the plurality of second nozzles being disposed on both axial sides of the pre-combustion chamber body, the plurality of first nozzles being evenly arranged around the axis of the pre-combustion chamber, the plurality of second nozzles being evenly arranged around the axis of the pre-combustion chamber, and the spacing between the plurality of first nozzles being greater than the spacing between the plurality of second nozzles.

[0008] According to a pre-combustion chamber provided by the present invention, the diameter of the large-diameter end of the nozzle is 1.1 to 1.5 times the diameter of the small-diameter end.

[0009] According to a pre-combustion chamber provided by the present invention, the angle between the axis of the nozzle and the axis of the pre-combustion chamber is . ~ .

[0010] According to a pre-combustion chamber provided by the present invention, the pre-combustion chamber has a tapered section extending along the axis of the pre-combustion chamber, and the nozzle is disposed near the small-diameter end of the tapered section.

[0011] The present invention also provides a gas engine, comprising: a cylinder liner, a cylinder head, a piston, and any one of the above-described pre-combustion chambers; The piston is movably disposed within the cylinder liner, and the cylinder head is connected to one end of the cylinder liner. The cylinder liner, piston, and cylinder head surround and form the main combustion chamber. The pre-combustion chamber body is disposed within the cylinder head, and the pre-combustion chamber and the main combustion chamber are coaxially arranged. The pre-combustion chamber is connected to the main combustion chamber through multiple injection holes.

[0012] According to a gas engine provided by the present invention, the piston has a combustion chamber recess at one end facing the cylinder head, the combustion chamber recess having a bottom surface and a side surface surrounding the bottom surface, the side surface having a plurality of raised ridges; The ridges extend along the depth of the combustion chamber recess, and multiple ridges are distributed at intervals around the axis of the piston. A flow guide area is formed between each pair of adjacent ridges, and multiple nozzles are arranged in a one-to-one correspondence with multiple flow guide areas.

[0013] According to a gas engine provided by the present invention, the portion of the side surface corresponding to the guide zone is an arc surface, and the jet landing point of the nozzle is located on the arc surface; the arc surface and the bottom surface are smoothly connected by a first arc surface, and the arc surface is smoothly connected to the convex ridges located on both sides thereof.

[0014] According to a gas engine provided by the present invention, the piston has a top surface at one end facing the cylinder head, and the combustion chamber recess has a transition plane; The transition plane and the top surface surround the side surface, and the arc surface and the transition plane are smoothly connected by a second arc surface. The smooth connection between the transition plane and the top surface forms a convection zone.

[0015] According to a gas engine provided by the present invention, the first arc surface and the second arc surface are located between two adjacent ridges, the first arc surface is smoothly connected to the ridges on both sides thereon, and the second arc surface is smoothly connected to the ridges on both sides thereon.

[0016] The pre-combustion chamber and gas engine provided by this invention, by setting gradually expanding nozzles on the pre-combustion chamber, with multiple nozzles spaced apart around the axis of the pre-combustion chamber and connecting the pre-combustion chamber and the main combustion chamber, the diameter of the gradually expanding nozzles gradually increases from the pre-combustion chamber to the main combustion chamber, which is beneficial for forcing the mixed gas in the main combustion chamber into the pre-combustion chamber during the compression stage, improving the ignition stability under cold start and low load conditions; at the same time, after the pre-combustion chamber is ignited, the gradually expanding nozzles help to increase the ignition area of ​​the high-energy particle jet in the main combustion chamber, avoiding the problem of nozzle blockage under supersonic jet conditions, thereby increasing the combustion speed and reducing the risk of cycle fluctuation and knocking. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the gas engine provided by the present invention.

[0019] Figure 2 This is a schematic diagram of the high-speed jet airflow motion inside the main combustion chamber of the gas engine provided by the present invention.

[0020] Figure 3 This is a schematic diagram of the piston structure of the gas engine provided by the present invention.

[0021] Figure 4 This is a schematic diagram of the high-speed jet airflow movement within the combustion chamber recess of the piston of the gas engine provided by the present invention.

[0022] Figure 5 This is a radial cross-sectional view of the piston of the gas engine provided by the present invention.

[0023] Figure 6 This is an axial sectional view of the piston of the gas engine provided by the present invention.

[0024] Figure 7 This is a graph showing the difference in cycle variation coefficients between the gas engine provided by this invention and a traditional gas engine.

[0025] Figure label: 11. Pre-combustion chamber body; 111. Pre-combustion chamber; 112. Nozzle; 12. Spark plug; 21. Cylinder liner; 22. Cylinder head; 23. Piston; 231. Combustion chamber recess; 2311. Bottom surface; 2312. Circular arc surface; 2313. Transition plane; 2314. Top surface; 232. Ridge; 24. Main combustion chamber; 2411. First circular arc surface; 2412. Second circular arc surface; 2413. Third circular arc surface; 2414. Fourth circular arc surface; 2415. Fifth circular arc surface; 2416. Sixth circular arc surface; 2417. Seventh circular arc surface. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0027] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "first"..."seventh" are numbering for the purpose of clearly identifying product components and do not represent any substantial difference. The terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances. Furthermore, "multiple" means two or more. In the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0028] The following is combined with Figures 1-7 The pre-combustion chamber and gas engine of the present invention are described.

[0029] like Figure 1 and Figure 2 As shown, the pre-combustion chamber provided in this embodiment of the invention includes a pre-combustion chamber body 11, which is provided with a pre-combustion cavity 111 and a plurality of nozzles 112. The plurality of nozzles 112 are arranged at intervals around the axis of the pre-combustion cavity 111. The nozzles 112 are gradually expanding holes, with the small-diameter end of the nozzles 112 communicating with the pre-combustion cavity 111, and the large-diameter end of the nozzles 112 being adapted to communicate with the main combustion cavity 24 of the engine.

[0030] The pre-combustion chamber provided in this embodiment of the invention is applied to a gas engine, which also includes a cylinder liner 21, a cylinder head 22, and a piston 23. The piston 23 is movably disposed within the cylinder liner 21, and the cylinder head 22 is connected to one end of the cylinder liner 21 to form a main combustion chamber. The cylinder liner 21, piston 23, and cylinder head 22 enclose a main combustion cavity 24. The pre-combustion chamber body 11 is adapted to be disposed within the cylinder head 22. The pre-combustion cavity 111 is connected to the main combustion cavity 24 through multiple nozzles 112, the diameter of which gradually increases from the pre-combustion cavity 111 towards the main combustion cavity 24.

[0031] The pre-combustion chamber can be either an active or passive pre-combustion chamber. When the pre-combustion chamber is an active pre-combustion chamber, it includes an independent gas supply system in addition to the spark plug 12. Both systems are located within the inner cavity of the pre-combustion chamber body 11, forming a pre-combustion chamber 111 together with the pre-combustion chamber body 11. When the pre-combustion chamber is a passive pre-combustion chamber, no independent gas supply system is required. The gas mixture in the main combustion chamber 24 enters the pre-combustion chamber 111 through the nozzle 112. Near top dead center, the gas mixture in the pre-combustion chamber 111 is ignited by the spark plug 12, and flame particles are injected at high speed into the main combustion chamber 24 through the nozzle 112, igniting the gas mixture in the main combustion chamber 24.

[0032] The pre-combustion chamber provided in this embodiment of the invention features a gradually expanding nozzle 112. Multiple nozzles 112 are spaced apart around the axis of the pre-combustion chamber 111 and connect the pre-combustion chamber 111 and the main combustion chamber 24. The diameter of the gradually expanding nozzle 112 gradually increases from the pre-combustion chamber 111 towards the main combustion chamber 24. This facilitates the compression of the mixed gas in the main combustion chamber 24 into the pre-combustion chamber during the compression stage, improving ignition stability under cold start and low load conditions. Simultaneously, after ignition in the pre-combustion chamber, the gradually expanding nozzle 112 helps increase the ignition area of ​​the high-energy particle jet in the main combustion chamber 24, avoiding nozzle 112 blockage under supersonic jet conditions, thereby increasing the combustion speed and reducing the risk of cyclic fluctuations and detonation.

[0033] Furthermore, in some embodiments of the present invention, multiple nozzles 112 are evenly arranged around the axis of the pre-combustion chamber 111. Specifically, with the pre-combustion chamber body 11 installed on the cylinder head 22, the pre-combustion chamber 111 is coaxial with the main combustion chamber 24. The high-speed jet within the pre-combustion chamber 111 can be evenly injected into the main combustion chamber 24 through the multiple nozzles 112, which helps improve combustion consistency, accelerates the combustion speed of the gas-mixture in the main combustion chamber 24, increases thermal efficiency, and reduces the risk of combustion knock.

[0034] In other embodiments, the plurality of nozzles 112 include a plurality of first nozzles and a plurality of second nozzles, which are respectively disposed on both axial sides of the pre-combustion chamber body 11. The plurality of first nozzles are evenly arranged around the axis of the pre-combustion chamber 111, and the plurality of second nozzles are evenly arranged around the axis of the pre-combustion chamber 111, with the spacing between the plurality of first nozzles being smaller than the spacing between the plurality of second nozzles.

[0035] The multiple first nozzles correspond to the intake valve side of the engine's main combustion chamber, and the multiple second nozzles correspond to the exhaust valve side of the engine's main combustion chamber. Temperature testing of the cylinder head 22 revealed that the exhaust valve side temperature was higher than the intake valve side temperature. By setting the spacing between the multiple first nozzles to be smaller than the spacing between the multiple second nozzles, the number of first nozzles is reduced to fewer than the number of second nozzles. This results in a more uniform temperature distribution within the main combustion chamber 24, reducing the risk of cylinder head cracking.

[0036] In an optional embodiment, the diameter of the larger diameter end of the nozzle 112 is 1.1 to 1.5 times the diameter of the smaller diameter end. This ensures ignition stability and prevents nozzle 112 blockage while maintaining the jet velocity at the nozzle 112 outlet. The nozzle 112 can be a circular orifice, or an elliptical or other shapes.

[0037] In an optional embodiment, the angle between the axis of the nozzle 112 and the axis of the pre-combustion chamber is... ~ For example, 65°, 70°, 75° or 80°.

[0038] The piston 23 of the gas engine has a combustion chamber recess 231 at one end facing the cylinder head 22. With this pre-combustion chamber installed on the cylinder head 22, the pre-combustion chamber 111 is coaxially aligned with the combustion chamber recess 231. The angle between the axis of the nozzle 112 and the axis of the pre-combustion chamber 111 is set to... ~ This allows the high-speed jet ejected from the nozzle 112 to land on the side of the combustion chamber recess 231. Part of the jet flame flows along the side towards the top of the combustion chamber recess 231, and part of the jet flame flows along the side towards the bottom of the combustion chamber recess 231, thus improving the air utilization rate of the main combustion chamber 24.

[0039] Based on the above embodiments, see Figure 2 The pre-combustion chamber 111 has a tapered section extending along the axis of the pre-combustion chamber, and nozzles 112 are disposed near the small-diameter end of the tapered section. Specifically, the pre-combustion chamber has a first end and a second end opposite to each other in its axial direction, the tapering direction of the tapered section is from the first end to the second end, and a plurality of nozzles 112 are disposed along the circumference of the second end. In this way, the flame propagation speed in the pre-combustion chamber can be increased, thereby increasing the jet velocity of the nozzles 112.

[0040] Specifically, the pre-combustion chamber 111 has a large-diameter section, a tapering section, and a small-diameter section connected sequentially along its axial direction, with the small-diameter section connected to the nozzle 112. The tapering section can be a conical section, while the large-diameter and small-diameter sections are cylindrical sections. The large-diameter end of the conical section is smoothly connected to the large-diameter section, and the small-diameter end of the conical section is smoothly connected to the small-diameter section.

[0041] This invention also provides a gas engine, including a cylinder liner 21, a cylinder head 22, a piston 23, and any one of the aforementioned pre-combustion chambers. The piston 23 is movably disposed within the cylinder liner 21, and the cylinder head 22 is connected to one end of the cylinder liner 21. The cylinder liner 21, piston 23, and cylinder head 22 enclose a main combustion chamber 24. The pre-combustion chamber body 11 is disposed within the cylinder head 22, and the pre-combustion chamber 111 and the main combustion chamber 24 are coaxially arranged. The pre-combustion chamber 111 is connected to the main combustion chamber 24 through multiple nozzles 112.

[0042] The cylinder liner 21, cylinder head 22, and piston 23 are assembled to form the main combustion chamber, and the cylinder liner 21, piston 23, and cylinder head 22 are arranged to form the main combustion cavity 24. The pre-combustion cavity 111, the main combustion cavity 24, and the piston 23 are arranged coaxially.

[0043] The gas engine provided in this embodiment of the invention, by setting multiple gradually expanding nozzles 112 on the pre-combustion chamber, facilitates the compression of the mixed gas in the main combustion chamber 24 into the pre-combustion chamber, improving ignition stability under cold start and low load conditions. After ignition in the pre-combustion chamber, the gradually expanding nozzles 112 help increase the ignition area of ​​the high-energy particle jet in the main combustion chamber, avoiding the problem of nozzle 112 blockage under supersonic jet conditions, thereby increasing the combustion speed of the mixed gas in the main combustion chamber 24 and reducing the risk of cycle fluctuations and knocking.

[0044] like Figure 2 and Figure 3 As shown in the embodiment of the invention, the piston 23 has a combustion chamber recess 231 at one end facing the cylinder head 22. The combustion chamber recess 231 has a bottom surface 2311 and a side surface surrounding the bottom surface 2311. The side surface has multiple ridges 232. The ridges 232 extend along the depth direction of the combustion chamber recess 231. The multiple ridges 232 are spaced apart around the axis of the piston 23, and a guide zone is formed between each pair of adjacent ridges 232. Multiple nozzles 112 are correspondingly arranged with the multiple guide zones.

[0045] It is understood that the ridge 232 protrudes towards the center of the combustion chamber recess 231 and extends along the depth direction of the combustion chamber recess 231, that is, the ridge 232 extends from the bottom of the combustion chamber recess 231 to the top of the combustion chamber recess 231. The top of the combustion chamber recess 231 corresponds to the edge opening of the combustion chamber recess 231.

[0046] The number of nozzles 112 is equal to the number of ridges 232. Multiple ridges 232 divide the side of the combustion chamber recess 231 into multiple flow-guiding zones, and the multiple nozzles 112 are arranged one-to-one with each flow-guiding zone. This ensures that the high-speed jet from the nozzles 112 lands within the flow-guiding zone and moves towards the ridges 232 on both sides, then moves along the sides of the ridges 232 towards the center of the main combustion chamber 24. Preferably, the two sides of the ridge 232 located on either side of the ridge line are smooth curved surfaces, and the two sides smoothly transition at the ridge line.

[0047] With multiple nozzles 112 arranged in a uniform circular array about the axis of the pre-combustion chamber 111, multiple ridges 232 are also arranged in a uniform circular array about the axis of the piston 23. Optionally, the number of ridges 232 is 6-12. See also Figure 3 There are six ridges 232, which are evenly distributed to form six evenly distributed flow guiding zones. Correspondingly, the pre-combustion chamber body 11 is provided with six nozzles 112, which are arranged one-to-one with the six flow guiding zones.

[0048] In embodiments where the multiple nozzles 112 include multiple first nozzles and multiple second nozzles, the arrangement of the multiple ridges 232 corresponds to the arrangement of the multiple first nozzles and multiple second nozzles, so as to ensure that the high-speed jet landing point of each nozzle 112 is located between two adjacent ridges 232.

[0049] See Figure 4 After ignition in the pre-combustion chamber, the jet flames ejected from multiple nozzles 112 move simultaneously from their impact point towards the two convex ridges 232 on both sides, and then, guided by the flow on both sides of the convex ridges 232, move towards the center of the main combustion chamber 24. The convex ridges 232 prevent jet flames from colliding within adjacent guide zones, reducing kinetic energy dissipation, which helps to increase the turbulence intensity within the main combustion chamber 24, accelerates the combustion speed of the mixture within the main combustion chamber, and thus reduces the risk of cycle fluctuations and detonation. (See also...) Figure 7 Compared to traditional gas engines, the gas engine provided in this embodiment has a reduced cycle variation coefficient and improved combustion stability.

[0050] In this embodiment of the invention, the distance between the side of the combustion chamber recess 231 corresponding to the guide zone and the axis of the piston 23 gradually increases from the bottom to the top of the combustion chamber recess 231, thus forming a non-constricted recess structure, which is beneficial for the guide zone to guide the jet flame falling towards it to the direction of the compression clearance at the top of the combustion chamber recess 231.

[0051] In some embodiments, the portion of the side of the combustion chamber recess 231 corresponding to the guide zone is an arc-shaped surface, and the jet landing point of the nozzle 112 is located on the arc-shaped surface 2312. The arc-shaped surface 2312 is smoothly connected to the bottom surface 2311, and the arc-shaped surface 2312 is smoothly connected to the ridges 232 located on both sides thereon.

[0052] In this embodiment, by setting the arc surface 2312, when the high-speed jet of the nozzle 112 moves along the arc surface 2312 towards the top of the combustion chamber pit 231 after landing, the airflow forms a certain angle with the horizontal plane of the cylinder head 22, which is conducive to the high-speed jet moving towards the compression clearance direction, thereby improving the air utilization rate of the compression clearance, increasing the turbulence intensity of the compression clearance, and further improving emissions and combustion efficiency.

[0053] The smooth transition between the curved surface 2312, the bottom surface 2311, and the convex ridges 232 on both sides allows for smoother airflow, forming stable vortices and improving combustion efficiency. Specifically, for example... Figure 5 As shown, the arc surface 2312 and the bottom surface 2311 are smoothly connected by the first arc surface 2411, and the arc surface 2312 and the convex ridges 232 located on both sides of it are smoothly connected by the fifth arc surface 2415.

[0054] In this embodiment of the invention, the bottom surface 2311 of the combustion chamber recess 231 can be a plane or a convex curved surface. For example... Figure 5 As shown, the bottom surface 2311 is an arc surface, and the radius R1 of the bottom surface 2311 is 1.0 to 1.2 times the diameter D0 of the piston 23.

[0055] Optionally, the radius R2 of the first arc surface 2411 is 0.05 to 0.09 times the diameter D0 of the piston 23, so as to ensure that the resistance and kinetic energy loss are minimized when the high-speed jet moves from the landing point to the bottom of the combustion chamber.

[0056] Optionally, the radius R3 of the arc surface 2312 is ≥ 0.8D0. The radius of the fifth arc surface 2415 is 0.5 to 1.0 times the radius R2 of the first arc surface 2411, to ensure that the resistance of the high-speed jet moving from the arc surface 2312 to the ridge 232 is small. The fifth arc surface 2415 is tangent to the arc of the ridge 232, so that the jets passing through the ridge 232 converge near the center of the main combustion chamber 24. The fifth arc surface 2415 is tangent to the arc of the ridge 232 at the diameter.

[0057] In this embodiment of the invention, the piston 23 is further provided with a top surface 2314 at the end facing the cylinder head 22, and the combustion chamber recess 231 is further provided with a transition plane 2313. The transition plane 2313 and the top surface 2314 surround the side of the combustion chamber recess 231, and the arc surface 2312 and the transition plane 2313 are smoothly connected by a second arc surface 2412. The smooth connection between the transition plane 2313 and the top surface 2314 forms a swirling zone.

[0058] The transition plane 2313 and the top surface 2314 are both annular surfaces surrounding the axis of the piston 23, with the transition plane 2313 located between the arc surface 2312 and the top surface 2314. From the bottom to the top of the combustion chamber recess 231, the bottom surface 2311, the arc surface 2312, the transition plane 2313, and the top surface 2314 are smoothly connected in sequence. By setting the transition plane 2313 between the second arc surface 2412 and the third arc surface 2413, the machining difficulty of the third arc surface 2413 can be reduced.

[0059] Specifically, the bottom surface 2311 and the arc surface 2312 are smoothly connected via a first arc surface 2411; the arc surface 2312 and the transition plane 2313 are smoothly connected via a second arc surface 2412; and the transition plane 2313 and the top surface 2314 are smoothly connected via a third arc surface 2413 and a fourth arc surface 2414, respectively. The transition plane 2313 and the third arc surface 2413 form a turbulence zone. When the high-speed jet from the nozzle 112 moves from the landing point towards the top of the combustion chamber recess 231, it is guided by the turbulence zone to form a turbulence zone at the compression clearance position, thereby increasing the turbulence intensity in the compression clearance and improving the combustion efficiency at that position, reducing pollutant emissions.

[0060] See Figure 2 In this embodiment of the invention, the combustion chamber recess 231, by setting an arc-shaped curved surface 2312 and a swirling zone, forms a non-constricted combustion chamber recess 231. This promotes the movement of the high-speed jet towards the swirling zone and the compression clearance direction, further improving the air utilization rate of the compression clearance, increasing the turbulence intensity of the compression clearance, and improving emissions and combustion efficiency. The design of the arc-shaped curved surface 2312 also allows for easy forging, which can greatly reduce the processing difficulty and cost.

[0061] Optionally, the radius R4 of the second arc surface 2412 is 0.3 to 0.8 times the radius R2 of the first arc surface 2411. The radius R5 of the third arc surface 2413 is 1.2 to 1.6 times the radius R2 of the first arc surface 2411. The radius R6 of the fourth arc surface 2414 is 0.1 to 0.3 times the radius R2 of the first arc surface 2411.

[0062] Optionally, the distance h1 between the bottom surface 2311 and the top surface 2314 is 0.2 to 0.3 times the diameter D0 of the piston 23. The distance h2 between the transition plane 2313 and the top surface 2314 is 0.1 to 1.5 times the distance h1.

[0063] In some embodiments of the present invention, the first arc surface 2411 and the second arc surface 2412 are located between two adjacent ridges 232. The first arc surface 2411 is smoothly connected to the ridges 232 on both sides thereon, and the second arc surface 2412 is smoothly connected to the ridges 232 on both sides thereon.

[0064] It is understood that each pair of adjacent ridges 232 has a first arc surface 2411, an arc surface 2312, and a second arc surface 2412, that is, the ridge 232 extends from the first arc surface 2411 to the second arc surface 2412. For example, the ridge 232 connects the bottom surface 2311 and the transition plane 2313, and the ridge 232 extends from the inner edge of the first arc surface 2411 to the outer edge of the second arc surface 2412.

[0065] Furthermore, the ridge 232 is smoothly connected to the arc surfaces 2312 on both sides of it via a fifth arc surface 2415, the ridge 232 is smoothly connected to the first arc surfaces 2411 on both sides of it via a sixth arc surface 2416, and the ridge 232 is smoothly connected to the second arc surfaces 2412 on both sides of it via a seventh arc surface 2417. Thus, the periphery of the ridge and the side surface of the combustion chamber recess 231 are smoothly connected.

[0066] like Figure 6 As shown, the angle between the radial tangents of the two adjacent sixth arc surfaces 2416 between two adjacent ridges 232 that are close to each other is α, and the angle between the radial tangents of the two distant edges of the two sixth arc surfaces 2416 on both sides of each ridge 232 is β, where α ≥ 0.6β. In this way, the high-speed airflow can maintain a high velocity when it changes from circumferential motion to radial motion, avoiding the formation of airflow dead zones.

[0067] The gas engine provided in this embodiment of the invention can use natural gas, hydrogen, ammonia, methanol, etc. Any single fuel can be used as the fuel for the main combustion chamber 24 and the pre-combustion chamber 111; or, the main combustion chamber 24 and the pre-combustion chamber 111 can each use any one of these fuels. This gas engine is suitable for equivalence mixtures (i.e., excess air coefficient φ=1) and also for lean mixtures (i.e., excess air coefficient φ>1).

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pre-chamber, characterized in that, include: The pre-combustion chamber body is provided with a pre-combustion cavity and multiple nozzles. The multiple nozzles are arranged at intervals around the axis of the pre-combustion cavity. The nozzles are gradually expanding holes. The small diameter end of the nozzle is connected to the pre-combustion cavity, and the large diameter end of the nozzle is adapted to be connected to the main combustion cavity of the engine.

2. The pre-chamber of claim 1, wherein, The plurality of spray holes are evenly arranged around the axis of the pre-combustion chamber; Alternatively, the plurality of nozzles may include a plurality of first nozzles and a plurality of second nozzles, the plurality of first nozzles and the plurality of second nozzles being disposed on both axial sides of the pre-combustion chamber body, the plurality of first nozzles being evenly arranged around the axis of the pre-combustion chamber, the plurality of second nozzles being evenly arranged around the axis of the pre-combustion chamber, and the spacing between the plurality of first nozzles being less than the spacing between the plurality of second nozzles.

3. The pre-chamber of claim 1, wherein, The diameter of the larger diameter end of the nozzle is 1.1 to 1.5 times the diameter of the smaller diameter end.

4. The pre-chamber of claim 1, wherein, An angle between an axis of the injection hole and an axis of the pre-combustion chamber is ​​ 5. A pre-chamber according to any one of claims 1 to 4, characterised in that, The pre-combustion chamber has a tapered section extending along the axis of the pre-combustion chamber, and the nozzle is located near the small-diameter end of the tapered section.

6. A gas engine characterized by include: Cylinder liner, cylinder head, piston, and pre-combustion chamber as described in any one of claims 1 to 5; The piston is movably disposed within the cylinder liner, and the cylinder head is connected to one end of the cylinder liner. The cylinder liner, piston, and cylinder head together form the main combustion chamber. The pre-combustion chamber body is located inside the cylinder head, and the pre-combustion chamber and the main combustion chamber are coaxially arranged. The pre-combustion chamber is connected to the main combustion chamber through multiple injection holes.

7. The gas engine of claim 6, wherein The piston has a combustion chamber recess at one end facing the cylinder head. The combustion chamber recess has a bottom surface and a side surface surrounding the bottom surface. The side surface is provided with a plurality of convex ridges. The ridges extend along the depth of the combustion chamber recess, and multiple ridges are distributed at intervals around the axis of the piston. A flow guide area is formed between each pair of adjacent ridges, and multiple nozzles are arranged in a one-to-one correspondence with multiple flow guide areas.

8. The gas engine of claim 7, wherein, The portion of the side surface corresponding to the guide area is an arc surface, and the jet landing point of the nozzle is located on the arc surface; the arc surface and the bottom surface are smoothly connected through a first arc surface, and the arc surface is smoothly connected to the convex ridges located on both sides thereon.

9. The gas engine of claim 8, wherein, The piston also has a top surface at the end facing the cylinder head, and the combustion chamber recess also has a transition plane; The transition plane and the top surface surround the side surface, and the arc surface and the transition plane are smoothly connected by a second arc surface. The smooth connection between the transition plane and the top surface forms a convection zone.

10. The gas engine of claim 9, wherein, The first arc surface and the second arc surface are located between two adjacent ridges. The first arc surface is smoothly connected to the ridges on both sides of it, and the second arc surface is smoothly connected to the ridges on both sides of it.

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