Combustion system, engine and combustion control method

Abstract

The present application relates to the technical field of internal combustion engine, and the present disclosure provides a kind of combustion system, including body;Piston, installation is in body;Cylinder cover, installation is in the opening position of body, cylinder cover, body and piston define first combustion chamber;First combustion part, is set in the middle position of cylinder cover to be used to inject fuel into first combustion chamber;Second combustion part, is set in the position of cylinder cover and is located in the side of first combustion part and is communicated with first combustion chamber, second combustion part includes: second combustion chamber, is formed in cylinder cover, the fuel of second combustion chamber is combusted prior to the fuel of first combustion chamber;Jet hole, is formed in the surface of cylinder cover opposite to piston, to form jet flame and ignite the fuel beam formed by the fuel in first combustion chamber.The present disclosure also provides an engine including combustion system, monitoring unit and control unit.And a kind of combustion control method of engine, including according to the position of the piston of engine, control the ignition timing of spark plug and the timing of injection to form coordination.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of internal combustion engines, and in particular to a combustion system, an engine and a combustion control method. BACKGROUND

[0002] Methanol, dimethyl ether, biodiesel, synthetic natural gas, polymethoxy dimethyl ether (PODE) and ammonia, and in particular low-carbon or zero-carbon fuels such as methanol, synthetic natural gas and ammonia, have great potential in reducing carbon emissions.

[0003] However, such low-carbon and zero-carbon fuels have low activity and are not easy to burn. When applied in the field of internal combustion engines, they are generally implemented in two ways: by igniting a premixed gas or by dual-fuel combustion (such as diesel / natural gas dual fuel).

[0004] Among them, the premixed ignition type has low combustion efficiency, poor small load combustion stability, high pressure rise rate at high load, and even knock, and the engine can only use a lower compression ratio due to knock limitation, so the thermal efficiency is poor. The dual-fuel method has poor carbon emission reduction effect because it still needs to burn diesel, and the engine structure is complex because it uses two sets of fuel systems. In addition, because these fuels have low activity and are not easy to ignite and burn, the use of compression self-ignition will cause problems such as poor combustion stability at small load conditions and even "misfire" and rough operation at high load conditions, and the engine has a high compression ratio, poor operation stability and poor reliability. SUMMARY

[0005] To solve the above technical problems, the present application provides a combustion system, an engine and a combustion control method.

[0006] One aspect of the present disclosure provides a combustion system, a cylinder block; a piston installed in the cylinder block; a cylinder head installed at an opening position of the cylinder block, the cylinder head, the cylinder block and the piston defining a first combustion chamber; a first combustion portion provided at a middle position of the cylinder head and communicating with the first combustion chamber, for injecting fuel into the first combustion chamber; and a second combustion portion provided at a position beside the first combustion portion on the cylinder head and communicating with the first combustion chamber, the second combustion portion comprising: a second combustion chamber formed in the cylinder head, the fuel in the second combustion chamber being combusted before the fuel in the first combustion chamber; and a jet hole formed in a surface of the cylinder head opposite to the piston, for forming a jet flame of the fuel combusted in the second combustion chamber to ignite a fuel beam formed by the fuel in the first combustion chamber, and causing the fuel beam in the first combustion chamber to combust in a diffusion combustion manner.

[0007] According to an embodiment of the present disclosure, the cylinder head further comprises: an intake passage formed on the cylinder head; and an exhaust passage formed on the other side of the cylinder head in radial direction symmetrically to the intake passage; wherein an intake valve is installed in the intake passage and can be opened and closed; and an exhaust valve is installed in the exhaust passage and can be opened and closed.

[0008] According to an embodiment of the present disclosure, the connecting line of the first combustion part and the second combustion part formed in the radial plane of the cylinder head is perpendicular to the connecting line of the intake passage and the exhaust passage.

[0009] According to an embodiment of the present disclosure, the first combustion part comprises a first fuel injector arranged at the middle of the cylinder head and extending into the first combustion chamber in the axial direction of the cylinder head; and the first fuel injector is provided with a spray hole in the circumferential direction at the axial first end in the first combustion chamber.

[0010] According to an embodiment of the present disclosure, a groove is formed on the surface of the piston opposite to the cylinder head, the surface of the groove is smooth, and the fuel sprayed by the spray hole of the first fuel injector forms a vortex on the surface of the groove.

[0011] According to an embodiment of the present disclosure, the second combustion part further comprises a second fuel injector arranged in the second combustion chamber to spray fuel into the second combustion chamber; and a spark plug arranged in the second combustion chamber to ignite the fuel sprayed by the second fuel injector.

[0012] According to another aspect of the present disclosure, an engine is also provided, comprising: the combustion system; a monitoring unit adapted to monitor the position of the piston; and a control unit adapted to control the ignition timing of the spark plug according to the position of the piston; wherein the second combustion part comprises the second fuel injector and the spark plug.

[0013] According to another aspect of the present disclosure, a combustion control method of an engine is also provided, comprising: monitoring the position of the piston of the engine; and controlling the ignition timing of the spark plug according to the position of the piston.

[0014] According to an embodiment of the present disclosure, monitoring the position of the piston of the engine comprises obtaining the position of the piston according to the angle of the crank angle of the crankshaft in one working cycle of the piston.

[0015] According to an embodiment of the present disclosure, controlling the ignition timing of the spark plug according to the position of the piston comprises: in one working cycle of the piston, spraying fuel by the second fuel injector during the process that the piston approaches the top dead center again, then igniting by the spark plug, and controlling the first fuel injector to spray fuel into the first combustion chamber based on the ignition timing of the spark plug, so as to realize the ignition of the fuel sprayed by the first fuel injector by the jet flame.

[0016] The present disclosure provides a combustion system, a device, a first combustion chamber is formed by the cooperation of a body, a piston and a cylinder head, and a first combustion part and a second combustion part are respectively arranged in the cylinder head. The first combustion part is used to input fuel into the first combustion chamber, and the second combustion part is used to pre-burn a part of the fuel, and then the jet flame formed by the pre-burned fuel ignites the fuel beam formed by the fuel in the first combustion chamber and makes the fuel beam in the first combustion chamber burn in a diffusion combustion manner.

[0017] The present disclosure also provides an engine, which has the advantages of the combustion system, and the time of fuel injection, the opening and closing of the valve and the timing of spark plug ignition are controlled based on the position and state of the piston through the cooperation of a monitoring unit and a control unit.

[0018] The present disclosure also provides a combustion control method to achieve relatively stable combustion at a small load and high combustion efficiency, and to effectively prevent the occurrence of deflagration at a large load. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a sectional view of a combustion system according to an illustrative embodiment of the present disclosure;

[0020] Figure 2 is a sectional view of a combustion system according to an illustrative embodiment of the present disclosure; Figure 1 is a sectional view of another angle of the illustrative embodiment shown in FIG. 1;

[0021] Figure 3 is a sectional view of another angle of the illustrative embodiment shown in FIG. 1; Figure 1 is a state diagram of the fuel injection state of the combustion system according to the illustrative embodiment shown in FIG. 1;

[0022] Figure 4 is a sectional view of another angle of the illustrative embodiment shown in FIG. 1; Figure 1 is a sectional view of another angle of the illustrative embodiment shown in FIG. 1;

[0023] Figure 5 is a schematic block diagram of an engine according to an illustrative embodiment of the present disclosure; and

[0024] Figure 6 is a flowchart of a combustion control method according to the present disclosure.

[0025] REFERENCE NUMERALS

[0026] 1, piston;

[0027] 2, body;

[0028] 3, cylinder head;

[0029] 4, first combustion chamber;

[0030] 5, injection hole;

[0031] 6. First injector;

[0032] 7. Injector end cap;

[0033] 8. Second combustion chamber;

[0034] 9. Spark plugs;

[0035] 10. Second fuel injector;

[0036] 11. Jet orifice;

[0037] 12. Air intake;

[0038] 13. Intake valve;

[0039] 14. Exhaust valve; and

[0040] 15. Exhaust duct. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0043] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0044] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). Similarly, when using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0045] Figure 1 is a cross-sectional view of a combustion system according to an illustrative embodiment of the present disclosure; Figure 2 is Figure 1 is a cross-sectional view of another angle of the illustrative embodiment shown; Figure 3 is Figure 1 is a state diagram of a fuel injection state of the combustion system of the illustrative embodiment shown; Figure 4 is Figure 1 is a bottom view of the cylinder head portion of the illustrative embodiment shown; Figure 5 is a schematic block diagram of an engine according to an illustrative embodiment of the present disclosure; Figure 6 is a flowchart of a combustion control method according to the present disclosure.

[0046] The present disclosure provides a combustion device, such as Figures 1 to 4 as shown, the combustion system includes a body 2, a piston 1 installed in the body 2, a cylinder head 3 installed at an opening position of the body 2, the body 2, the piston 1 and the cylinder head 3 defining a first combustion chamber 4, a first combustion portion provided in the middle of the cylinder head 3 to inject fuel into the first combustion chamber 4, and a second combustion portion provided in the cylinder head 3 to form a jet flame and ignite the fuel of the first combustion chamber 4, wherein the second combustion portion includes a second combustion chamber 8 formed in the cylinder head 3 and a jet hole 11 formed on the surface of the cylinder head 3 opposite to the piston 1, the fuel in the second combustion chamber 8 is combusted before the fuel in the first combustion chamber 4, and a jet flame is formed in the first combustion chamber 4 through the jet hole 11 to ignite the fuel in the first combustion chamber 4.

[0047] In detail, the fuels used in the first combustion portion and the second combustion portion can be consistent, for example, a large amount of fuel is injected into the first combustion portion, and a small amount of fuel is injected into the second combustion portion, and the jet flame generated after the combustion of the small amount of fuel is used to ignite the fuel in the first combustion chamber. It should be understood that the embodiments of the present disclosure are not limited thereto.

[0048] For example, the fuels used in the first combustion portion and the second combustion portion are inconsistent. A first fuel that is not easy to burn is injected into the first combustion portion, and a second fuel that is easy to burn is injected into the second combustion portion, and the jet flame generated after the combustion of the second fuel is used to ignite the first fuel in the first combustion chamber.

[0049] According to the embodiments of the present disclosure, the combustion device further includes an intake port 12 formed on the cylinder head 3, and an exhaust port 15 symmetrically arranged on the cylinder head 3 with the intake port 12. Wherein, the intake valve 13 is installed in the intake port 12 in an openable and closable manner, and the exhaust valve 14 is installed in the exhaust port 15 in an openable and closable manner.

[0050] According to an embodiment of the present disclosure, in a plane formed in the radial direction of the cylinder head 3, the line connecting the first combustion portion and the second combustion portion is perpendicular to the line connecting the intake port 12 and the exhaust port 15. In order to form a bias design of the second combustion portion relative to the first combustion portion, the design purpose of igniting the first combustion portion by the second combustion portion is achieved by designing the parameters of the injection hole 5 and the jet hole 11, including but not limited to position, diameter, length of the jet hole, etc.

[0051] According to an embodiment of the present disclosure, as shown in Figure 3 and Figure 4 , the first combustion portion includes a first fuel injector 6 arranged in the middle of the cylinder head 3 and extending into the first combustion chamber 4 along the axial direction of the cylinder head 3. The first fuel injector 6 is arranged circumferentially at the axial first end of the first combustion chamber 4.

[0052] In detail, the number of injection holes 5 is six to eight, and the six injection holes 5 are arranged uniformly and circumferentially.

[0053] In detail, the first fuel injector 6 is fixed to the end cover through the fuel injector end cover 7.

[0054] Further, the number of injection holes 5 can be designed according to the actual fuel injection requirement and flow. It should be understood that the embodiments of the present disclosure are not limited thereto.

[0055] For example, the number of injection holes 5 is other numbers.

[0056] Further, the position of the injection hole 5 can also be designed according to the type of fuel and the relative position of the second combustion portion.

[0057] According to an embodiment of the present disclosure, a groove is formed on the surface of the piston 1 facing the cylinder head 3, and the surface of the groove is smooth. The fuel injected by the injection hole 5 of the first fuel injector forms a vortex through the surface of the groove.

[0058] In detail, the surface of the piston facing the cylinder head forms a groove, and the groove bottom is smooth and rounded.

[0059] Further, the middle of the groove and the position of the first combustion portion orthographic projection form a protrusion, and the protrusion and the groove bottom are integrally formed. After the fuel is injected into the groove, it is blocked by the groove bottom and extends radially outward along the groove bottom to form a vortex. It should be understood that the embodiments of the present disclosure are not limited thereto.

[0060] For example, the shape of the groove should be designed according to the position of the first combustion portion and the position of the injection hole 5 formed by the first fuel injector 6.

[0061] And since the piston 1 moves along the engine body 2, the shape of the groove should also be designed according to the position of the piston 1 relative to the engine body 2.

[0062] For example, the shape of the recess should meet the design purpose that when the piston 1 goes up to a certain position, the fuel injected by the first fuel injector 6 can form a vortex in the recess.

[0063] According to an embodiment of the present disclosure, as shown in Figure 3 and Figure 4 The second combustion part includes a second combustion chamber 8 formed in the cylinder head 3, the second combustion chamber 8 is provided with a second fuel injector 10 and a spark plug 9, and the surface of the cylinder head 3 facing the piston 1 is further provided with a jet hole 11 for communicating the second combustion chamber and the first combustion chamber, so that the fuel burned in the second combustion chamber 8 forms a jet flame.

[0064] In detail, the lower end of the second combustion chamber 8 is located in the first combustion chamber 4.

[0065] Further, the second combustion chamber 8 is a biased second combustion chamber relative to the first combustion chamber 4.

[0066] Further, each jet hole 11 communicating with the second combustion chamber 8 can be designed individually according to actual needs, for example, the position, number and parameters (including but not limited to angle, aperture and length) of the jet hole 11, so as to meet the requirement that the second combustion chamber 8 can form a jet flame and the jet flame can effectively ignite the fuel in the first combustion chamber 4.

[0067] For example, the number of jet holes 11 is consistent with the number of injection holes 5 of the first fuel injector 6. And the jet flame formed by the jet hole 11 and the path of the fuel injected by the injection hole 5 partially overlap.

[0068] For example, the number of jet holes 11 is not consistent with the number of injection holes 5.

[0069] For example, the downward inclination angle of the jet hole 11 close to the first fuel injector 6 is smaller than that of the jet hole 11 on the other side, so that the jet flames injected by the two sides can both contact the corresponding fuel and effectively ignite, so as to improve the ignition effect of the jet flame on the fuel in the first combustion chamber 4.

[0070] For example, the angle and position of the jet hole 11 are consistent.

[0071] For example, the length, aperture and angle of the jet hole 11 are designed as a whole to control the speed of the fuel injected by the jet hole 11 and the like.

[0072] According to another aspect of the present disclosure, an engine is also provided, as shown in Figure 5As shown, the engine comprises a monitoring unit and a control unit. The monitoring unit is configured to monitor the position of the piston 1, and the control unit is configured to control the injection time of the first injector 6 and / or the second injector 10, the opening and closing of the intake valve 13 and / or the exhaust valve 14, and the ignition timing of the spark plug 9 according to the position of the piston 1.

[0073] According to another aspect of the present disclosure, there is also provided a combustion control method of an engine, comprising: Figure 6 As shown, the engine comprises a monitoring unit and a control unit. The monitoring unit is configured to monitor the position of the piston 1, and the control unit is configured to control the injection time of the first injector 6 and / or the second injector 10, the opening and closing of the intake valve 13 and / or the exhaust valve 14, and the ignition timing of the spark plug 9 according to the position of the piston 1.

[0074] According to an embodiment of the present disclosure, the monitoring of the position of the piston 1 of the engine comprises obtaining the position of the piston 1 according to the angle of the crank angle of the crankshaft in one working cycle of the piston 1.

[0075] According to an embodiment of the present disclosure, the control of the ignition timing of the spark plug 9 according to the position of the piston 1 comprises, in one working cycle of the piston 1, injecting fuel by the second injector 10 during the process that the piston 1 approaches the top dead center again, then igniting by the spark plug 9, and controlling the injection of fuel into the first combustion chamber 4 by the first injector 6 based on the ignition timing of the spark plug 9, so as to achieve the effective ignition of the fuel injected by the first injector by the jet flame.

[0076] In detail, the piston 1 first descends from the top dead center, at this time, the intake valve 13 is opened, the exhaust valve 14 is closed, and fresh air enters the first combustion chamber 4 and the second combustion chamber 8 through the intake port; when the piston 1 passes the bottom dead center, the intake valve 13 is closed, and the piston 1 moves upward to compress the air in the cylinder, so that the temperature and pressure of the air are continuously increased, and the second injector 10 starts to inject fuel, and the injected fuel mixes with the air in the second combustion chamber 8 to form a uniform mixture; when the piston 1 moves to approach the top dead center, the spark plug 9 ignites to ignite the combustible mixture in the second combustion chamber 9, and the fuel combustion releases heat, causing the temperature and pressure in the second combustion chamber 8 to increase sharply, so the pressure difference between the second combustion chamber 8 and the first combustion chamber 4 gradually increases, and the combustion flame in the second combustion chamber 8 is injected from the jet hole 11 to form a jet flame; and the first injector 6 also starts to inject fuel, and due to the high injection pressure, the fuel spray is injected to the edge of the first combustion chamber 4, so that the jet flame can ignite the combustible mixture at the end of the spray; after the combustible mixture at the end of the spray in the first combustion chamber 4 is ignited, a diffusion combustion flame is formed, and a large amount of heat is released by the fuel combustion to drive the piston 1 to move downward and output mechanical work; when the piston 1 moves to approach the bottom dead center, the exhaust valve 14 is opened, the piston 1 moves upward to exhaust the exhaust gas in the combustion chamber, and the whole working process is completed.

[0077] According to the combustion system, the engine and the combustion control method provided by the present disclosure, 1, the jet flame formed by the second combustion chamber ignites the low-active fuel in the first combustion chamber, so that the low-active fuel can realize diffusion combustion, and the diffusion combustion has high efficiency, so that the combustion system and the engine provided by the present disclosure have high combustion efficiency and thermal efficiency. 2, the low-active fuel in the first combustion chamber is ignited by the jet flame, which can significantly improve the ignition and combustion stability of the low-active fuel under small load conditions. 3, compared with the premixed ignition method in the prior art, the problem of too high boost pressure under heavy load conditions can be effectively avoided. 4, the fuel quantity entering the first combustion chamber and / or the second combustion chamber can be adjusted according to the real-time change of the load, so as to effectively improve the stable combustion of the combustion system under full load conditions. Further, under small load conditions, the fuel quantity of the second combustion chamber is increased, the jet flame ignition effect is enhanced, the combustion stability is effectively improved, under heavy load conditions, the fuel injection strategy is optimized, and the combustion is effectively prevented from being too rough.

[0078] The above describes the embodiments of the present disclosure. However, these embodiments are only for illustrative purposes, and are not intended to limit the scope of the present disclosure. Although each embodiment is described above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A combustion system, comprising: Body (2); Piston (1) is installed inside the body (2); Cylinder head (3) is installed at the opening of the engine block (2), and the cylinder head (3), engine block (2) and piston (1) define a first combustion chamber (4). A first combustion section is disposed in the middle of the cylinder head (3) and communicates with the first combustion chamber (4) for injecting fuel into the first combustion chamber (4). The first combustion section includes a first injector (6) disposed in the middle of the cylinder head (3) and extending axially into the first combustion chamber (4). The first injector (6) has a spray hole circumferentially disposed at its first axial end within the first combustion chamber (4). The second combustion section is disposed on the cylinder head (3) at a position next to the first combustion section and communicates with the first combustion chamber (4). The second combustion section includes: A second combustion chamber (8) is formed inside the cylinder head (3), and the fuel in the second combustion chamber (8) burns before the fuel in the first combustion chamber (4); A second fuel injector (10) is disposed within the second combustion chamber (8) for injecting fuel into the second combustion chamber (8); and A spark plug (9), disposed in the second combustion chamber (8), is used to ignite fuel injected by the second injector (10); and The jet orifice (11) is formed on the surface of the cylinder head (3) opposite to the piston (1) to form a jet flame of the fuel burning in the second combustion chamber (8) to ignite the fuel bundle formed by the fuel in the first combustion chamber (4) and to make the fuel bundle in the first combustion chamber (4) burn in a diffusion combustion manner. The path of the jet flame formed by the jet orifice (11) and the path of the fuel ejected by the nozzle (5) partially overlap. In this invention, a groove is formed on the surface of the piston (1) facing the cylinder head (3). The surface of the groove is smoothly arranged. A protrusion is formed at the middle of the groove and at the position of the orthogonal projection of the first combustion section. The fuel injected by the nozzle of the first injector (6) forms a vortex on the surface of the groove.

2. The combustion system according to claim 1, further comprising: An intake manifold (12) is formed on the cylinder head (3); as well as An exhaust manifold (15) is formed on the other radial side of the cylinder head (3) that is symmetrical to the intake manifold (12); The intake duct (12) is equipped with an intake valve (13) that can be opened and closed; the exhaust duct (15) is equipped with an exhaust valve (14) that can be opened and closed.

3. The combustion system according to claim 2, wherein, The line connecting the first combustion section and the second combustion section in the radial plane of the cylinder head (3) is perpendicular to the line connecting the intake manifold (12) and the exhaust manifold (15).

4. An engine comprising: The combustion system as described in any one of claims 1 to 3; The monitoring unit is suitable for monitoring the position of the piston (1); as well as The control unit is adapted to control the ignition timing of the second combustion section according to the position of the piston (1); The second combustion section includes a second fuel injector (10) and a spark plug (9).

5. A combustion control method based on the engine of claim 4, comprising: Monitor the position of the engine piston (1); as well as The ignition timing of the spark plug (9) is controlled according to the position of the piston (1).

6. The control method according to claim 5, wherein, Monitoring the position of the piston (1) of the engine includes obtaining the position of the piston (1) based on the angle of the crankshaft rotation of the crankshaft linked to the piston (1) during one working cycle of the piston.

7. The control method according to claim 5, wherein, The ignition timing of the spark plug (9) is controlled according to the position of the piston (1). This includes the second injector (10) injecting fuel during one working cycle of the piston when the piston (1) approaches the top dead center again, after which the spark plug (9) ignites, and the first injector (6) is controlled to inject fuel into the first combustion chamber (4) based on the ignition timing of the spark plug (9), so as to achieve the ignition of the fuel injected by the first injector (6) by the jet flame.

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