COMBUSTION SYSTEM CONTROL METHOD, COMBUSTION SYSTEM AND ENGINE

Abstract

A combustion system control method, a combustion system, and an engine are disclosed, and the combustion system control method includes an injector (10) performing a first main injection and a second main injection at an interval, the injector injecting fuel into a first arcuate ridge (3) during the first main injection, and the injector injecting fuel into a second arcuate ridge (6) during the second main injection. By adopting a combustion chamber with two arcuate ridges and injecting fuel into the two arcuate ridges respectively through injectors, it is possible to ensure that the amount of fuel allocated to each arcuate ridge is small, and it is possible to avoid too much fuel gathering at a single arcuate ridge, which is beneficial to the effect of the arcuate ridge improving the jet velocity field where the tip of the oil jet collides with the wall. In addition, the two arcuate ridges can guide and distribute the fuel from the two main injections, which facilitates the strengthening of the distribution of oil and gas in the cylinder, improves the utilization rate of the air in the cylinder chamber, improves the combustion efficiency, and further improves the thermal efficiency of the engine.

Description

[Technical Field]

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on June 17, 2021, bearing application number 202110669898.1 and entitled "Control method for combustion system, combustion system and engine," the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to the technical field of engines, and in particular to a method for controlling a combustion system, a combustion system and an engine. [Background technology]

[0003] The combustion structure of conventional diesel engines is primarily diffusion combustion, and the combustion speed is largely limited by the mixing speed of oil and gas. Furthermore, current high-pressure common-rail diesel engines all use a single main injection. The entrainment effect of a single high-pressure injection mainly occurs in the atomization region, resulting in weak entrainment in the middle of the oil jet, resulting in poor oil-gas mixing. Furthermore, most combustion chambers designed for a single main injection use a single-stage arc-ridge structure, which distributes a large amount of fuel to the tip of the oil jet, particularly at the arc-ridge, preventing the arc-ridge from effectively improving the jet velocity field where the tip of the oil jet hits the wall. Furthermore, due to the high engine speed, the time for oil-gas mixing is very short compared to four-stroke engines. The jets and droplets generated by a single main injection are difficult to disperse and atomize in a timely manner within the combustion chamber to form a uniform air-fuel mixture, which restricts the rapid progression of the combustion process and further limits the engine's power output. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to provide a control method for a combustion system, a combustion system and an engine, so as to solve the problem that the combustion systems in the related art usually adopt a single main injection, which is disadvantageous to sufficient mixing of oil and gas. [Means for solving the problem]

[0005] Meanwhile, the present invention provides a control method for a combustion system, the combustion system including a piston, a cylinder, and an injector, the piston being slidably positioned within a cylinder chamber of the cylinder, a combustion chamber being provided at the top of the piston and communicating with the cylinder chamber, a side wall of the combustion chamber having a first arcuate ridge and a second arcuate ridge spaced apart, the first arcuate ridge and the second arcuate ridge both protruding into the combustion chamber, the control method for the combustion system including the injector performing a first main injection and a second main injection at an interval, the injector injecting fuel onto the first arcuate ridge during the first main injection, and the injector injecting fuel onto the second arcuate ridge during the second main injection, the fuel injection speeds of the first main injection and the second main injection being equal to or greater than a set speed.

[0006] In a preferred technical solution of the combustion system control method, when the injector performs the first main injection, the piston rises in the cylinder and can compress the gas in the cylinder chamber, and when the injector performs the second main injection, the piston falls in the cylinder.

[0007] In a preferred technical solution of the combustion system control method, when the injector performs a first main injection, the oil injection hole of the injector faces the center position of the first arc-shaped ridge, the pitch between the oil injection hole of the injector and the center of the first arc-shaped ridge is L1, the speed at which the oil injection hole of the injector injects oil is V1, and the ignition delay period of the fuel injected in the first main injection is t1, where t1=L1 / V1.

[0008] In a preferred technical solution of the combustion system control method, when the injector performs a second main injection, the oil injection hole of the injector faces the center position of the second arc-shaped ridge, the pitch between the oil injection hole of the injector and the second arc-shaped ridge is L2, the speed at which the oil injection hole of the injector injects oil is V2, and the ignition delay period of the fuel injected in the second main injection is t2, where t2 = L2 / V2.

[0009] In a preferred technical solution of the combustion system control method, the vertical pitch between the center of the first arcuate ridge and the center of the second arcuate ridge is equal to H1, and the displacement between the position of the piston during the first main injection of the injector and the position of the piston during the second main injection of the injector is equal to H2, where H1=H2.

[0010] In a preferred technical solution of the combustion system control method, the injector continues to inject fuel during the period between the first main injection and the second main injection, and the fuel injection speed of the injector is smaller than the set speed.

[0011] On the other hand, the present invention provides a combustion system used in the combustion system control method in any of the above schemes, the combustion system comprising: a cylinder having a cylinder chamber; a piston slidably positioned within the cylinder chamber of the cylinder, with a combustion chamber at its top that communicates with the cylinder chamber, the piston having a side wall of the combustion chamber with a first arcuate ridge and a second arcuate ridge spaced apart, the first arcuate ridge and the second arcuate ridge both projecting into the combustion chamber; an injector for injecting oil into the combustion chamber; a control system for controlling the rate of fuel injection of the injector, the control system being capable of controlling the injector to inject fuel at or above a set rate onto the first arcuate ridge, and the control system being capable of controlling the injector to inject fuel at or above a set rate onto the second arcuate ridge.

[0012] In a preferred technical solution of the combustion system, the first arcuate ridge is closer to the center of the combustion chamber than the second arcuate ridge, and the second arcuate ridge is closer to the top surface of the combustion chamber than the first arcuate ridge.

[0013] In a preferred technical solution of the combustion system, the first arc-shaped ridge forms a first circular arc in a vertical cross section of the combustion chamber, the second arc-shaped ridge forms a second circular arc in the vertical cross section of the combustion chamber, the radius of the first circular arc is R1, the radius of the second circular arc is R2, and R1=2R2~3R2.

[0014] Furthermore, the present invention provides an engine including a combustion system according to any of the above solutions.

[0015] The beneficial effects of the present invention are as follows: The present invention provides a combustion system control method, a combustion system, and an engine, the combustion system control method including the steps of: an injector performing a first main injection and a second main injection at an interval; the injector injecting fuel onto a first arcuate ridge during the first main injection, allowing the fuel to rebound and splash; and the injector injecting fuel onto a second arcuate ridge during the second main injection, allowing the fuel to rebound and splash, and the fuel injection speeds of the first main injection and the second main injection are both equal to or greater than a set speed. By adopting a combustion chamber with two arc-shaped ridges and using injectors to inject fuel into each of the two arc-shaped ridges, it is possible to ensure that the amount of fuel allocated to each arc-shaped ridge is small, preventing too much fuel from concentrating at a single arc-shaped ridge. This is beneficial for the arc-shaped ridges to improve the jet velocity field where the oil jet tip hits the wall. In addition, the two arc-shaped ridges guide and distribute the fuel from the two main injections, which facilitates the strengthening of the distribution of oil and gas in the cylinder, improves the utilization of air in the cylinder chamber, improves combustion efficiency, and further enhances the thermal efficiency of the engine. [Brief explanation of the drawings]

[0016] [Figure 1] 2 is a structural schematic diagram of a combustion chamber and an injector of a piston according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] The technical solutions of the present invention are clearly and completely described below in conjunction with the accompanying drawings, and the described embodiments are not all embodiments but only a part of the embodiments of the present invention. All other embodiments obtained based on the embodiments of the present invention without the need for creative work by those skilled in the art are all within the scope of protection of the present invention.

[0018] In describing the present invention, the orientations or positional relationships indicated by the terms "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inside," "outside," etc. are orientations or positional relationships shown in the drawings, and are merely for the convenience of describing and simplifying the present invention. They are not intended to indicate or imply that the referred devices or elements must have a specific orientation or be configured and operated in a specific orientation, and therefore should not be understood as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to mean or imply relative importance. The terms "first position" and "second position" refer to two different positions, and the terms "above," "above," and "top" of a first feature include the first feature being directly above and diagonally above the second feature, or simply indicate that the first feature is higher horizontally than the second feature. A first feature being "below," "below," and "at the bottom" of a second feature includes the first feature being directly below and diagonally below the second feature, or simply indicating that the first feature is lower in horizontal height than the second feature.

[0019] In the description of the present invention, unless otherwise clearly specified or limited, the terms "attached," "coupled," and "connected" should be interpreted broadly, and it should be explained that they may be, for example, fixedly connected, detachably connected, or integrally connected, may be mechanically connected, may be electrically connected, may be directly connected, may be indirectly connected via an intermediate medium, or may be internal communication between two elements. Those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0020] The following describes in detail the embodiments of the present invention. An example of the embodiment is shown in the drawings, and the same or similar reference numerals always represent the same or similar elements, or elements having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and are used only to interpret the present invention, and should not be understood as limiting the present invention.

[0021] As shown in FIG. 1, this embodiment provides a combustion system, which includes a cylinder, a piston, an injector 10, and a control system.

[0022] The cylinder has a cylinder chamber, the piston is positioned within the cylinder chamber and slides therein, and a combustion chamber communicating with the cylinder chamber is provided at the top of the piston. The piston can reciprocate within the cylinder when driven by a crankshaft or the like.

[0023] The sidewall of the combustion chamber has a first arcuate ridge 3 and a second arcuate ridge 6 spaced apart, both of which project into the combustion chamber. Specifically, the combustion chamber has a structure as shown in FIG. 1, which is roughly a W-shaped combustion chamber. FIG. 1 shows only half of the cross section of the combustion chamber, which has a top plane 9, a tapered bottom plane 1, and an annular side wall connecting the top plane 9 and the bottom plane 1. The side wall specifically includes, arranged in order from bottom to top, a main arcuate surface 2, a first arcuate ridge 3, a first slope 4, a transition arc 5, a second arcuate ridge 6, a second slope 7, and a throat transition surface 8. The bottom plane 1, main arcuate surface 2, first arcuate ridge 3, first slope 4, transition arc 5, second arcuate ridge 6, second slope 7, throat transition surface 8, and top plane 9 are sequentially adjacent and connected to each other. In addition, the main arcuate surface 2 is recessed inward, and the first arcuate ridge 3 is closer to the center of the combustion chamber than the second arcuate ridge 6, and the second arcuate ridge 6 is closer to the top surface of the combustion chamber than the first arcuate ridge 3. In this embodiment, the first arc-shaped ridge 3 is closer to the center of the combustion chamber than the second arc-shaped ridge 6 along the depth direction of the combustion chamber. Preferably, the first arc-shaped ridge 3 forms a first circular arc 2 in the vertical cross section of the combustion chamber, and the second arc-shaped ridge 6 forms a second circular arc in the vertical cross section of the combustion chamber, with the radius of the first arc 2 being R1 and the radius of the second arc being R2, where R1 = 2R2 ~ 3R2. When installed in this manner, the first arc-shaped ridge 3 has a large oil-receiving area and is located in the center, which facilitates rebounding the fuel to various positions in the combustion chamber and allowing it to be thoroughly mixed with the air at the top, middle, and bottom of the combustion chamber.

[0024] The injector 10 is for injecting oil into a combustion chamber, and the control system is for controlling the speed of fuel injection by the injector 10. The control system can control the injector 10 to inject fuel into the first arcuate ridge 3 at a speed equal to or greater than a set speed, and can control the injector 10 to inject fuel into the second arcuate ridge 6 at a speed equal to or greater than the set speed. The injector 10 supplies fuel via an oil pump, and the control system can include a controller and a control valve. The control valve is provided in a connecting line between the oil supply pump and the injector 10, and the control valve is connected to the controller. The controller can adjust the flow rate of the fuel through the control valve and further control the speed of the fuel ejected from the injector 10. As will be understood, when the injector 10 injects fuel at a speed equal to or greater than the set speed, it indicates that the injector 10 is performing main injection, and when the injector 10 injects fuel at a speed lower than the preset speed, it indicates that the injector 10 is performing pre-injection. By adopting a combustion chamber with two arcuate ridges and injecting fuel into each of the two arcuate ridges via the injector 10, it is possible to ensure that the amount of fuel allocated to each arcuate ridge is small, and it is possible to avoid a large amount of fuel concentrating at a single arcuate ridge. This is advantageous for the arcuate ridges to improve the jet velocity field where the tip of the oil jet collides with the wall, and is also advantageous for the fuel droplets to be thoroughly mixed with the air.

[0025] This embodiment also provides a combustion system control method that can be implemented by the above-mentioned combustion system. Specifically, the combustion system control method includes the steps of: an injector 10 performing a first main injection and a second main injection at an interval; the injector 10 injecting fuel into the first arcuate ridge 3 during the first main injection, allowing the fuel to bounce back; and the injector 10 injecting fuel into the second arcuate ridge 6 during the second main injection, allowing the fuel to bounce back, with the fuel injection speeds of the first and second main injections being equal to or greater than a set speed. The two arcuate ridges guide and distribute the fuel from the two main injections, thereby enhancing the distribution of oil and gas in the cylinder, improving the utilization of air in the cylinder chamber, improving combustion efficiency, and further improving the thermal efficiency of the engine.

[0026] In other embodiments, the combustion chamber may further include three or more arcuate ridges. Taking three arcuate ridges as an example, the combustion chamber may further include a third arcuate ridge spaced apart from the first arcuate ridge 3 and the second arcuate ridge 6, with the third arcuate ridge protruding outward into the combustion chamber. The injector 10 may perform three main injections at intervals during the piston movement, and the oil jets of the three main injections may be controlled to fall on the three arcuate ridges, respectively, to further enhance the mixing effect of the oil and gas.

[0027] Furthermore, when the injector 10 performs the first main injection, the piston rises within the cylinder, compressing the gas in the cylinder chamber. When the injector 10 performs the second main injection, the piston may descend within the cylinder. This fully accommodates the symmetry of the piston's ascending and descending movements, subdivides the location of the fuel drop point, and fully utilizes the flow-diverging and splashing effects of the two arc-shaped ridges. Preferably, the vertical pitch between the center of the first arc-shaped ridge 3 and the center of the second arc-shaped ridge 6 is equal to H1, and the displacement between the piston's position during the first main injection of the injector 10 and the piston's position during the second main injection of the injector 10 is equal to H2, where H1 = H2. This eliminates the need to adjust the orientation of the oil injection hole of the injector 10, and allows the fuel to be accurately injected onto the two arc-shaped ridges as the piston ascends and descends.

[0028] In addition, the injector 10 may continue to inject fuel during the period between the first main injection and the second main injection, and the fuel injection speed of the injector 10 may be lower than the set speed. This arrangement can further promote uniform mixing of oil and gas in the cylinder chamber.

[0029] 1, when the injector 10 performs the first main injection, the oil injection hole of the injector 10 faces the center of the first arcuate ridge 3. The distance between the oil injection hole of the injector 10 and the center of the first arcuate ridge 3 is L1, the speed at which the oil injection hole of the injector 10 injects fuel is V1, and the ignition delay of the fuel injected in the first main injection is t1, where t1 = L1 / V1. With this arrangement, after the fuel is ejected from the injector 10, it contacts the first arcuate ridge 3 after time t1 has elapsed, splashing and then entering a rapid combustion period, without affecting the splashing effect of the subsequent fuel on the first arcuate ridge 3. The ignition delay of the fuel can be adjusted and controlled according to the temperature, oil quality, etc.

[0030] Furthermore, when the injector 10 performs the second main injection, the oil injection hole of the injector 10 faces the center position of the second arcuate ridge 6, the pitch between the oil injection hole of the injector 10 and the second arcuate ridge 6 is L2, the speed at which the oil injection hole of the injector 10 injects the fuel is V2, and the ignition delay period of the fuel injected in the second main injection is t2, where t2 = L2 / V2. With this arrangement, after the fuel is ejected from the injector 10, it comes into contact with the second arcuate ridge 6 after the time t2 has elapsed, and after splashing, it enters a rapid combustion period, without affecting the splashing effect of the subsequent fuel on the second arcuate ridge 6.

[0031] This embodiment further provides an engine including the combustion system of the above solution.

[0032] Obviously, the above examples of the present invention are not limited to the embodiments of the present invention, but are merely examples provided to clearly explain the present invention. Those skilled in the art may make further changes and modifications based on the above description. It is not necessary or possible to list all the embodiments one by one here. Various modifications, alternations, and improvements in accordance with the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0033] 1 Bottom 2. Main arc surface 3. First arc-shaped ridge 4. First slope 5. Transition Arc 6 Second arc-shaped ridge 7 Second Slope 8 Throat transition surface 9...Top plane 10 Injector

Claims

1. a combustion system including a piston, a cylinder, and an injector (10), the piston slidingly positioned within a cylinder chamber of the cylinder, a combustion chamber being provided at the top of the piston and communicating with the cylinder chamber, a side wall of the combustion chamber having a first arcuate ridge (3) and a second arcuate ridge (6) spaced apart, the first arcuate ridge (3) and the second arcuate ridge (6) both protruding into the combustion chamber; a control method for a combustion system, the injector (10) performing a first main injection and a second main injection at an interval, the control method further including the steps of: injecting fuel into the first arcuate ridge (3) during the first main injection; and injecting fuel into the second arcuate ridge (6) during the second main injection, the speeds of fuel injection in the first main injection and the second main injection being equal to or greater than a set speed; Along the depth direction of the combustion chamber, the first arcuate ridge (3) is closer to the center of the combustion chamber than the second arcuate ridge (6), the first arcuate ridge (3) forms a first arc in a vertical cross section of the combustion chamber, the second arcuate ridge (6) forms a second arc in the vertical cross section of the combustion chamber, and the radius of the first arc is R １ and the radius of the second arc is R ２ Let R １ =2R ２ ~3R ２ That is, A method for controlling a combustion system.

2. When the injector (10) performs the first main injection, the piston rises in the cylinder and can further compress gas in the cylinder chamber, and when the injector (10) performs the second main injection, the piston falls in the cylinder.

2. The method of claim 1, wherein the combustion system is controlled by the combustion control system.

3. When the injector (10) performs the first main injection, the oil injection hole of the injector (10) faces the center position of the first arc-shaped ridge (3), and the pitch between the oil injection hole of the injector (10) and the center of the first arc-shaped ridge (3) is set to L. １ The speed at which the fuel oil is injected from the oil injection hole of the injector (10) is V １ and the ignition delay period of the fuel injected in the first main injection is t １ Let t １ =L １ / V １ That is, 3. The method of claim 2, wherein the combustion system is controlled by the combustion control system.

4. When the injector (10) performs the second main injection, the oil injection hole of the injector (10) faces the center position of the second arc-shaped ridge (6), and the pitch between the oil injection hole of the injector (10) and the second arc-shaped ridge (6) is set to L ２ The speed at which the fuel oil is injected from the oil injection hole of the injector (10) is V ２ and the ignition delay period of the fuel injected in the second main injection is t ２ Let t ２ =L ２ / V ２ That is, 3. The method of claim 2, wherein the combustion system is controlled by the combustion control system.

5. The vertical pitch between the center of the first arcuate ridge (3) and the center of the second arcuate ridge (6) is H １ and the displacement between the position of the piston at the time of the first main injection of the injector (10) and the position of the piston at the time of the second main injection of the injector (10) is equal to H ２ becomes equal to H １ = H ２ That is, 3. The method of claim 2, wherein the combustion system is controlled by the combustion control system.

6. the injector (10) continues to inject fuel during a period between the first main injection and the second main injection by the injector (10), and the speed of fuel injection by the injector (10) is smaller than the set speed; 3. The method of claim 2, wherein the combustion system is controlled by the combustion control system.

7. A combustion system for implementing the combustion system control method according to any one of claims 1 to 6, a cylinder having a cylinder chamber; a piston slidably positioned within the cylinder chamber of the cylinder, with a combustion chamber at its top communicating with the cylinder chamber, the combustion chamber having a side wall with a first arcuate ridge (3) and a second arcuate ridge (6) spaced apart, the first arcuate ridge (3) and the second arcuate ridge (6) both projecting into the combustion chamber; an injector (10) for injecting oil into the combustion chamber; a control system for controlling the rate of fuel injection of the injector (10), the control system being capable of controlling the injector (10) to inject fuel into the first arcuate ridge (3) at or above a set rate, and the control system being capable of controlling the injector (10) to inject fuel into the second arcuate ridge (6) at or above a set rate; Along the depth direction of the combustion chamber, the first arcuate ridge (3) is closer to the center of the combustion chamber than the second arcuate ridge (6), the first arcuate ridge (3) forms a first arc in a vertical cross section of the combustion chamber, the second arcuate ridge (6) forms a second arc in the vertical cross section of the combustion chamber, and the radius of the first arc is R １ and the radius of the second arc is R ２ Let R １ =2R ２ ~3R ２ That is, A combustion system characterized by:

8. The second arcuate ridge (6) is closer to the top surface of the combustion chamber than the first arcuate ridge (3).

8. The combustion system of claim 7.

9. 9. A combustion system comprising: a combustion system according to claim 7 or 8; An engine characterized by:

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