Horizontal opposed two-stroke engine spiral flame combustion system

Abstract

The invention provides a horizontally-opposed two-stroke engine spiral flame combustion system which comprises a cylinder sleeve, a piston combustion chamber, an exhaust port, oil sprayers, an air inlet and a piston combustion chamber, the piston combustion chamber, the exhaust port, the oil sprayers, the air inlet and the piston combustion chamber are sequentially arranged above the cylinder sleeve from top to bottom, and the two oil sprayers are installed on the same horizontal plane; spraying holes of the oil sprayer are non-uniformly distributed on the nozzle and are mainly concentrated on one side of the oil sprayer. According to the horizontally-opposed two-stroke engine spiral flame combustion system, when the thermodynamic atmosphere in the cylinder reaches the ignition condition of oil-gas mixture, rotating annular flames are formed in the cylinder, spiral flames are formed in the descending process of the piston, and the combustion efficiency is improved. According to the combustion organization mode, the oil-gas mixing efficiency can be improved through rotational flowing of fluid in the cylinder, and the flame speed can be increased through vortex of the fluid in the cylinder after ignition.

Description

Technical Field

[0001] The invention belongs to the technical field of horizontally opposed two-stroke engines, and in particular relates to a spiral flame combustion system of a horizontally opposed two-stroke engine. Background Art

[0002] The horizontally opposed two-stroke engine has no cylinder head or camshaft, and has two pistons in a single cylinder, which is very beneficial to improving the engine volume power. It has obvious technical advantages in application scenarios where the engine volume is limited but the power demand is large. However, the horizontally opposed two-stroke engine has different ventilation and oil-gas mixing processes from traditional four-stroke and traditional two-stroke engines. The poor oil-gas mixing uniformity during the combustion process leads to low air utilization and thermal efficiency. Summary of the invention

[0003] In view of this, the present invention aims to propose a spiral flame combustion system for a horizontally opposed two-stroke engine to solve the problems of high rotational flow of fluid in the cylinder, low oil-gas mixing efficiency and long combustion cycle.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A spiral flame combustion system for a horizontally opposed two-stroke engine comprises a cylinder liner and a piston combustion chamber, an exhaust port, a fuel injector, an air inlet and a piston combustion chamber arranged in sequence from top to bottom on the cylinder liner, two fuel injectors are installed on the same horizontal plane and the angle between the two fuel injectors is 180 degrees, and the spray holes of the fuel injectors are unevenly distributed on the nozzle and are mainly concentrated on one side of the fuel injector.

[0006] Furthermore, the angle α between the spray holes on the two injector nozzles in the horizontal plane ranges from 10° to 80°, and the angle β between the spray holes in the vertical direction ranges from 5° to 70°.

[0007] Furthermore, the direction of the air inlet forms an angle with the cylinder liner.

[0008] Furthermore, the installation plane of the injector is perpendicular to the cylinder liner.

[0009] Furthermore, the piston combustion chamber is an inverted umbrella-shaped pit with a protrusion in the middle, and the edge of the pit has two involute notches near the spray holes of the two injectors.

[0010] Furthermore, the height of the protrusion in the middle of the pit is ±3 mm from the top of the piston.

[0011] Compared with the prior art, the horizontally opposed two-stroke engine spiral flame combustion system of the present invention has the following advantages:

[0012] (1) The spiral flame combustion system of the horizontally opposed two-stroke engine described in the present invention sprays droplets into the cylinder at a suitable advance angle before the top dead center, and gradually forms an annular oil-gas mixture rotating in the cylinder near the top dead center through the interaction between the movement of the oil droplets and the airflow in the cylinder; when the thermodynamic atmosphere in the cylinder reaches the ignition condition of the oil-gas mixture, a rotating annular flame is formed in the cylinder, and a spiral flame is formed during the downward movement of the piston. This combustion organization method can improve the oil-gas mixing efficiency through the rotational flow of the fluid in the cylinder, and the vortex of the fluid in the cylinder after ignition can accelerate the flame speed.

[0013] (2) The horizontally opposed two-stroke engine spiral flame combustion system described in the present invention can improve the thermal efficiency by 7% compared with the non-spiral flame combustion system under certain working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0015] Figure 1 A schematic diagram of an air port and a cylinder liner of a spiral flame combustion system of a horizontally opposed two-stroke engine according to an embodiment of the present invention;

[0016] Figure 2 A schematic diagram of the piston combustion chamber and the direction of the spray hole of the spiral flame combustion system of the horizontally opposed two-stroke engine according to an embodiment of the present invention;

[0017] Figure 3 for Figure 2 Sectional view along AA direction;

[0018] Figure 4 The simulated temperature field distribution of the spiral flame combustion system of the horizontally opposed two-stroke engine according to the embodiment of the present invention Figure 1 ;

[0019] Figure 5 The simulated temperature field distribution of the spiral flame combustion system of the horizontally opposed two-stroke engine according to the embodiment of the present invention Figure 2 .

[0020] Description of reference numerals:

[0021] 1- cylinder liner, 2- intake port, 3- injector, 4- exhaust port, 5- piston combustion chamber. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0026] A spiral flame combustion system for a horizontally opposed two-stroke engine, such as Figures 1 to 5 As shown, it includes a cylinder liner 1 and a piston combustion chamber 5, an exhaust port 4, an injector 3, an air intake port 2 and a piston combustion chamber 5 arranged in sequence from top to bottom above it. Two injectors 3 are installed on the same horizontal plane and the angle between the two injectors is 180°. The spray holes of the injector 3 are unevenly distributed on the nozzle, mainly concentrated on one side of the injector 3.

[0027] The angle α of the spray holes on the two injectors 3 in the horizontal plane ranges from 10° to 80°, and the angle β in the vertical direction ranges from 5° to 70°.

[0028] The direction of the air inlet 2 forms an angle with the surface of the cylinder liner 1. This inclined air inlet 2 can effectively ensure that a strong vortex is formed in the cylinder after the air inlet is closed.

[0029] Then, the direction of the injector spray hole is designed to match the direction of rotation of the vortex in the cylinder, and the installation plane of the injector 3 is perpendicular to the cylinder liner 1. At the appropriate advance angle before the top dead center, the spray droplets are sprayed into the cylinder. Through the interaction between the movement of the oil beam 3 droplets and the airflow in the cylinder, an annular oil-gas mixture that rotates in the cylinder is gradually formed near the top dead center. When the thermodynamic atmosphere in the cylinder reaches the ignition condition of the oil-gas mixture, a rotating annular flame is formed in the cylinder, and a spiral flame is formed during the downward movement of the piston. This combustion organization method can improve the oil-gas mixing efficiency through the rotational flow of the fluid in the cylinder, and the vortex of the fluid in the cylinder after ignition can accelerate the flame speed.

[0030] The piston combustion chamber 5 is an inverted umbrella-shaped pit with a raised center, and the edge of the pit has two involute notches near the spray holes of the two injectors 3. The height of the raised center of the pit is ±3 mm from the top of the piston.

[0031] Figure 3 As shown in the cross-sectional view, the height of the protrusion in the middle of the pit is 0 mm from the top of the piston.

[0032] For the spiral flame that is distributed in a ring shape in the cylinder, there will be a hollow area in the middle of the flame. In order to make full use of the air in the cylinder and improve the homogeneity of the mixed gas distribution in the cylinder, a central bulge is designed in the middle of the combustion chamber pit on the top of the piston, which can effectively reduce the air enrichment area. There are avoidance structures for the injectors on both sides of the combustion chamber.

[0033] The working principle of a spiral flame combustion system of a horizontally opposed two-stroke engine is:

[0034] Fresh air entering the cylinder liner 1 from the air inlet 2 will form a strong horizontal vortex in the cylinder liner 1. When it is close to the top dead center, the two injectors 3 will spray fuel into the cylinder liner 1. The oil beam formed by the fuel droplets moves together with the fluid in the cylinder liner 1 to form a "doughnut" type oil-gas mixture. When the hot atmosphere in the cylinder liner 1 reaches the chemical reaction condition for the mixture to ignite, a "doughnut" type oil-gas mixture is formed. Figure 4 and Figure 5 Temperature field inside the spiral flame cylinder.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A spiral flame combustion system for a horizontally opposed two-stroke engine, characterized in that: It includes a cylinder liner and a piston combustion chamber, an exhaust port, a fuel injector, an air intake port and a piston combustion chamber arranged in sequence from top to bottom on the cylinder liner. Two fuel injectors are installed on the same horizontal plane and the angle between the two fuel injectors is 180 degrees. The spray holes of the fuel injector are unevenly distributed on the nozzle and are mainly concentrated on one side of the fuel injector.

2. A horizontally opposed two-stroke engine spiral flame combustion system according to claim 1, characterized in that: The angle α of the spray hole directions on the two injector nozzles in the horizontal plane ranges from 10° to 80°, and the angle β in the vertical direction ranges from 5° to 70°.

3. The spiral flame combustion system of a horizontally opposed two-stroke engine according to claim 1, characterized in that: The direction of the air inlet is at an angle to the cylinder liner.

4. A horizontally opposed two-stroke engine spiral flame combustion system according to claim 1, characterized in that: The installation plane of the injector is perpendicular to the cylinder liner.

5. The spiral flame combustion system of a horizontally opposed two-stroke engine according to claim 1, characterized in that: The piston combustion chamber is an inverted umbrella-shaped pit with a raised center, and the edge of the pit has two involute notches near the spray holes of the two injectors.

6. A horizontally opposed two-stroke engine spiral flame combustion system according to claim 5, characterized in that: The height of the protrusion in the middle of the pit is ±3mm from the top of the piston.

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