A heavy oil engine combustion system and a heavy oil engine

Abstract

The present application provides a kind of heavy oil engine combustion system, including machine case, reed valve mounting seat, air inlet pipe, cylinder body and piston, the machine case is equipped with air inlet, the reed valve mounting seat is fixedly arranged with air inlet, the air inlet pipe is installed on the reed valve mounting seat, the cylinder body is arranged in machine case both sides, the cylinder body includes combustion chamber in its inner cavity top, the top of the cylinder body is provided with air injection nozzle assembly and spark plug, the piston is arranged in the cylinder body, and can reciprocate along the axial direction of cylinder body, the piston includes combustion-supporting structure in top, the combustion-supporting structure sequentially includes annular spherical surface portion, first annular recessed portion, first annular convex portion, second annular recessed portion and central boss portion along radial direction from outside to inside.The present application is equipped with double heating structure plus the unique curved surface design of piston top and the position cooperation of air injection nozzle and spark plug, which jointly constitute the combustion system of the present application, greatly improve fuel activity, atomization effect, ignition capacity, combustion efficiency and combustion stability.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to a heavy oil engine combustion system and a heavy oil engine. Background Technology

[0002] Heavy fuel oil engines are the future trend, but heavy fuel oil has high viscosity and is difficult to atomize, which makes it difficult to mix the fuel and gas and form a uniform fuel-gas mixture. This can easily cause difficulties in cold starting the engine, carbon buildup on spark plugs, and high fuel consumption. In addition, heavy fuel oil has a low octane rating and slow flame propagation speed, which makes the engine prone to knocking under high load and can easily limit the engine's power output.

[0003] Current technologies for improving air-fuel mixture efficiency employ optimized fuel injector methods, directly injecting fuel into the corresponding combustion chamber area to enhance mixing efficiency. This technology places extremely high demands on the fuel injectors and is difficult to manufacture. Improving ignition efficiency involves widening the carburetor injection angle to directly inject fuel mist onto the spark plug for ignition. However, for engines using heavy fuel oil, this method can lead to wet-wall combustion, reducing combustion efficiency and increasing fuel consumption.

[0004] Therefore, it is necessary to provide a heavy oil engine combustion system and a heavy oil engine to overcome the defects mentioned above. Summary of the Invention

[0005] The purpose of this invention is to provide a heavy oil engine combustion system and a heavy oil engine.

[0006] According to one aspect of the present invention, a heavy oil engine combustion system is provided, comprising: A casing, wherein an air inlet is provided on the casing; A reed valve mounting base is fixedly disposed with the air inlet; An intake pipe, which is mounted on the reed valve mounting base; A cylinder block is disposed on both sides of the casing. The cylinder block includes a combustion chamber located at the top of its inner cavity. A clump injector assembly and a spark plug are disposed at the top of the cylinder block. The piston is disposed in the cylinder body and can reciprocate along the axial direction of the cylinder body. The piston includes a combustion-promoting structure located at the top. The combustion-promoting structure includes, in radial order from the outside to the inside, an annular spherical part, a first annular recess, a first annular protrusion, a second annular recess, and a central boss.

[0007] Preferably, the piston top is convex in shape. On a cross-section passing through the piston axis, the combustion-promoting structure is symmetrically arranged about the piston axis. Describing the cross-section of the combustion-promoting structure on the left side of the axis, the annular spherical part is an arc with its center at the bottom and extending upward, the first annular recess is an arc with its center at the top and extending upward, the first annular protrusion is an arc with its center at the bottom and protruding upward, and the second annular recess is an arc with its center at the top and concave downward.

[0008] Preferably, the annular spherical part is tangentially connected to the first annular recess, the first annular protrusion is tangentially connected to the first annular recess, the first annular protrusion is tangentially connected to the second annular recess, and the second annular recess is tangentially connected to the central boss.

[0009] Preferably, the center of the annular spherical part is located on the axis of the piston, the radius of the annular spherical part is R1, the cylinder diameter is D, then 2D≤R1≤3.5D, the radius of the first annular recess is R2, then R2≥D, the second annular recess is set to correspond to the oil mist trajectory sprayed by the air-clamping injector assembly, and the tangent at the end of the second annular recess can intersect with the spark plug on the same side after extension.

[0010] Preferably, the upper central surface of the central boss is a plane.

[0011] Preferably, a heating grille is provided between the intake pipe and the reed valve mounting seat, a throttle valve is integrated on the intake pipe, and a temperature sensor is provided on the throttle valve.

[0012] Preferably, the air-clamping injector assembly includes a housing, a pressure regulating valve, an injector, and an air-clamping nozzle. The pressure regulating valve and the injector are located inside the housing, and the air-clamping nozzle is partially located inside the housing and partially extends out of the housing.

[0013] Preferably, the outer casing includes an oil inlet, an air inlet, and a heating element. The air inlet is located at the end of the heating element, and the incoming air can be heated by the heating element.

[0014] Preferably, the outer casing further includes a first mounting portion and a second mounting portion. The first mounting portion is disposed away from the air inlet, and the second mounting portion is disposed close to the air inlet. Both the first mounting portion and the second mounting portion are connected to the heating portion and are internally interconnected. The first mounting portion is provided with a temperature sensor, and the second mounting portion is provided with a heating element.

[0015] Preferably, the heating element extends into the heating section to heat the air entering the heating section, and the temperature sensor extends into the heating section to detect the temperature of the heated air.

[0016] Preferably, the air-clamping nozzle is located at the top of the cylinder block and on the central axis of the cylinder block, opposite to the central boss, and the spark plug is arranged symmetrically about the air-clamping nozzle.

[0017] According to another aspect of the present invention, a heavy oil engine is provided, comprising the above-described heavy oil engine combustion system.

[0018] Compared with the prior art, the heavy oil engine combustion system and heavy oil engine provided by the present invention have the following beneficial effects: Due to the adoption of the above technical solution, the present invention has the advantages of simple structure, ingenious design and low cost. Through the combustion-promoting structure at the top of the piston and its positional cooperation with the spark plug and air-fuel injector assembly, the injected mixture can bounce at the top of the piston to promote evaporation and mixing, and can obtain better mixture quality at the spark plug. This allows the spark plug electrode to contact the appropriate fuel mixture more quickly, thereby improving ignition capability. The combustion-promoting structure can effectively guide the backflow of scavenging gas, replace the exhaust gas in the dead zone of the combustion chamber, reduce the residual coefficient of the exhaust gas in the combustion chamber, and improve the scavenging efficiency. At the same time, it is beneficial to improve the structural stability, anti-knock properties and reliability of the engine. In the air-clamped injector assembly, the intense movement of the air-fuel mixture in the fuel mixing chamber is amplified by heating the compressed air, thereby improving the atomization effect of heavy fuel oil. Combined with the heating grille, dual heating is achieved, further solving problems such as difficulty in cold start, slow fuel evaporation and atomization, difficulty in forming a uniform air-fuel mixture, and high fuel consumption rate. Attached Figure Description

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a perspective view of the heavy oil engine combustion system of the present invention; Figure 2 This is a cross-sectional view of the heating grille of the heavy oil engine combustion system of the present invention; Figure 3 This is a cross-sectional view of the heavy oil engine of the present invention; Figure 4 This is a cross-sectional view of the air-clamping injector assembly of the present invention; Figure 5 This is a top cross-sectional view of the piston of the present invention; Figure 6 for Figure 5 A magnified view of a portion of the image; Figure 7 This is a cross-sectional view of the cylinder block of the heavy oil engine combustion system of the present invention; Figure 8 This is a perspective view of the piston of the present invention.

[0020] The components are as follows: 1. Casing; 2. Reed valve mounting seat; 3. Heating grille; 4. Intake pipe; 41. Throttle valve; 5. Cylinder block; 51. Combustion chamber; 6. Piston; 61. Combustion-promoting structure; 611. Annular spherical part; 612. First annular recess; 613. First annular protrusion; 614. Second annular recess; 615. Central boss; 7. Air-clamping injector assembly; 71. Outer shell; 711. Upper shell; 7111. Oil return port; 7112. Oil inlet; 712. Lower shell; 7121. Air inlet; 7122. Heating unit; 7123. First mounting part; 7124. Second mounting part; 72. Pressure regulating valve; 73. Injector; 74. Air-clamping nozzle; 75. Temperature sensor; 76. Heating element; 8. Spark plug; 91. Crankshaft; 92. Connecting rod. Detailed Implementation

[0021] To more clearly illustrate the technical solutions in the embodiments of the present 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] To keep the drawings concise, only the parts relevant to the invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of components with the same structure or function is shown schematically, or only one is labeled. In this document, "one" can mean not only "only one" but also "more than one".

[0023] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0024] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0027] See Figure 1 and Figure 3 This embodiment discloses a heavy oil engine combustion system, including a casing 1, a reed valve mounting seat 2, a heating grille 3, an intake pipe 4, a cylinder, and a piston 6. The cylinder body 5 is fixed to both sides of the casing 1, and the piston 6 is disposed within the cylinder body 5. A crankshaft 91 is provided within the casing 1. The piston 6 is connected to the crankshaft 91 via a connecting rod 92, and can reciprocate along the axial direction of the cylinder body 5 under the drive of the crankshaft 91.

[0028] See Figure 2 and Figure 3 The engine casing 1 has a vent for supplying fresh air to the engine, located at the top of the casing 1. A reed valve mounting seat 2 is fixed to the vent, and a heating grille 3 is fixed to the reed valve mounting seat 2. The intake pipe 4 is fixed to the heating grille 3. A throttle valve 41 is integrated into the intake pipe 4, and a temperature sensor is installed on the throttle valve 41 to monitor the intake air temperature and control the intake air volume. The cylinder block 5 has a chuck injector assembly 7 and a spark plug 8 at its end. Outside air enters the engine casing 1 through the intake pipe 4, passing through the heating grille 3 and the reed valve mounting seat 2 in sequence. The heating grille 3 can directly heat the incoming fresh air. The intake air heating method effectively improves the atomization effect and enhances the cold start performance of heavy oil engines, especially two-stroke heavy oil engines.

[0029] See Figure 7 The cylinder block 5 includes a combustion chamber 51 located at the top of its inner cavity. A gas injector assembly 7 and spark plugs 8 are disposed on the top of the cylinder block 5. The gas injector assembly 7 is located at the center of the top of the cylinder block 5, and there are two spark plugs 8, which are disposed on both sides of the gas injector assembly.

[0030] See Figure 4 The air-clamping injector assembly 7 includes a housing 71, a pressure regulating valve 72, an injector 73, and an air-clamping nozzle 74. The housing 71 includes an upper housing 711 and a lower housing 712. The pressure regulating valve 72 and the injector 73 are located inside the housing 71 and between the upper housing 711 and the lower housing 712. The air-clamping nozzle 74 is partially located inside the lower housing 712 and partially extends out of the lower housing 712.

[0031] The upper housing 711 includes an oil return port 7111 and an oil inlet 7112, while the lower housing 712 includes an air inlet 7121 and a heating element 7122. The oil return port 7111 is equipped with an oil return connector, the oil inlet 7112 is equipped with an oil inlet connector, and the air inlet 7121 is equipped with an air inlet connector. The air inlet 7121 is located at the end of the heating element 7122; incoming fresh air is first heated by the heating element 7122 before entering the lower housing 712.

[0032] The lower housing 712 also includes a first mounting portion 7123 and a second mounting portion 7124 disposed adjacent to each other. The first mounting portion 7123 is disposed away from the air inlet 7121, and the second mounting portion 7124 is disposed close to the air inlet 7121. Both the first mounting portion 7123 and the second mounting portion 7124 are connected to the heating portion 7122 and are internally interconnected. The first mounting portion 7123 is provided with a temperature sensor 75, and the second mounting portion 7124 is provided with a heating element 76.

[0033] In this embodiment, the heating element 76 is a heating plug that extends into the heating section 7122 to heat the air entering the heating section 7122. The temperature sensor 75 extends into the heating section 7122 to detect the temperature of the heated air. Fresh air passes through the air inlet 7121, is heated by the heating element 76, and then flows to the temperature sensor 75. The temperature sensor 75 detects whether the temperature of the heated air has reached a preset value; if not, it raises the temperature of the heating element 76.

[0034] External compressed air enters through the intake port 7121 and is accelerated through the heating section 7122, which has an internal shape similar to a Venturi tube (Laval effect). After being heated by the heating plug and flowing rapidly, the compressed air enters the fuel mixing chamber and mixes with the fuel injected by the injector 73. The temperature of the hot air is transferred to the fuel particles, which can accelerate the thermal motion of the fuel particles, making the fuel particles smaller. Finally, the fuel particles are injected into the cylinder block 5 by the air-clamping nozzle 74 and ignited.

[0035] Of course, the heated plugs are not always working while the engine is running. In this embodiment, the heated plugs are activated by the heating relay in the ECU control harness before heating. When the temperature sensor 75 detects that the incoming compressed air reaches 140°C, the heated plugs stop heating. When the compressed air temperature is below 120°C, the heated plugs continue heating.

[0036] The upper housing 711 has a high-pressure oil passage connected to the oil return port 7111 and the oil inlet port 7112. The lower housing 712 has a high-pressure air passage connected to the air inlet port 7121. The air pressure in the air passage is kept constant at 6 bar by an air pump, while the oil pressure is controlled by a pressure regulating valve 72. The pressure regulating valve 72 is preset with a pressure difference of 1.5 bar. When the oil pressure exceeds the air pressure at the other end of the pressure regulating valve 72 by 1.5 bar (i.e., the oil pressure is 7.5 bar), the excess oil returns to the fuel tank through the oil return port 7111. The 7.5 bar high-pressure aviation fuel is injected into the fuel-air mixing chamber through the injector 73, and finally injected into the combustion chamber 51 through the air-jet nozzle 74 to participate in combustion.

[0037] See Figure 5 , Figure 6 and Figure 8 The piston 6 includes a combustion-promoting structure 61 located at the top. The combustion-promoting structure 61, radially from the outside to the inside, includes an annular spherical portion 611, a first annular recess 612, a first annular protrusion 613, a second annular recess 614, and a central boss 615. The annular spherical portion 611 is located at the outermost ring of the piston 6 top, and the central boss is located at the center of the piston 6 top. A chuck nozzle 74 is located at the top of the cylinder block 5 and on the central axis of the cylinder block 5, opposite to the central boss. The spark plug 8 is centrally symmetrical about the chuck nozzle 74.

[0038] The top of piston 6 is generally convex. In a cross-section passing through the axis of piston 6, the combustion-promoting structure 61 is symmetrically arranged about the axis of piston 6. Describing the cross-section of the combustion-promoting structure 61 on the left side of the axis, the annular spherical part 611 is an arc with its center at the bottom and extending upward, the first annular recess 612 is an arc with its center at the top and extending upward, the first annular protrusion 613 is an arc with its center at the bottom and protruding upward, and the second annular recess 614 is an arc with its center at the top and concave downward.

[0039] The annular spherical portion 611 is tangentially connected to the first annular recess 612, the first annular protrusion 613 is tangentially connected to the first annular recess 612, the first annular protrusion 613 is tangentially connected to the second annular recess 614, and the second annular recess 614 is tangentially connected to the central boss 615. The center of the annular spherical portion 611 is located on the axis of the piston 6, and the radius of the annular spherical portion 611 is R1. The cylinder diameter of the cylinder block 5 is D, satisfying 2D≤R1≤3.5D. In this embodiment, R1=3D. This configuration is used to cooperate with the scavenging port design of the cylinder block 5, reduce scavenging disturbance resistance, and at the same time, when the piston 6 is in the compression stage, it forms a high-speed squeeze flow with the combustion chamber 51 wall of the cylinder block 5, enhancing the fuel-air mixing efficiency.

[0040] The radius of the first annular recess 612 is R2, which satisfies R2≥D. The first annular recess 612 is a concave arc design, with the starting point of the arc tangent to the annular spherical surface 611. The inclination angle α of the tangent at the end of the arc is between 45° and 55°, and this tangent intersects with the air-clamping nozzle 74. This structure can achieve the replacement of exhaust gas in the scavenging dead zone of the cylinder combustion chamber 51 when the piston 6 moves upward, reducing the exhaust gas retention rate, improving the overall power performance and economy of the engine, and reducing carbon deposits on the spark plug 8.

[0041] The second annular recess 614 is the oil jet guiding area. Its end extending towards the first annular protrusion 613 is an upward arc shape. The tangent of the end of the arc can intersect with the spark plug 8 on the same side. The inclination angle b of the tangent at the end of the arc is controlled between 5° and 20°.

[0042] The overall position of the second annular recess 614 depends on the installation position of the spark plug 8. It adopts a concave rounded corner design, ensuring that the concave rounded corner is on the oil mist trajectory of the air-jet injector assembly 7. The sprayed oil mist trajectory is shown in Figure 7. This structure allows the oil mist to be buffered by first colliding with the second annular recess 614, and then guided to the ignition position of the spark plug 8 through the rounded corner trajectory, increasing ignition efficiency. The tangential extension of the end of the second annular recess 614 intersects with the spark plug 8 on the same side, ensuring the correct oil mist trajectory after guidance. The oil mist buffered in this area can also more effectively avoid wall wetting, effectively improving the ignition efficiency of heavy oil and reducing fuel consumption.

[0043] The central upper surface of the central boss is flat. This structural design effectively improves the piston 6's resistance to high temperatures and strong impacts during high-speed operation, thereby extending the piston 6's lifespan. The vertical cross-section of the piston 6's top upper surface is similar to a wave, meaning the combustion-promoting structure 61 also has a similar wave-like cross-section in the vertical direction. This curved design creates a more complex flow pattern within the combustion chamber 51, enhancing vortices, which helps in the formation of the air-fuel mixture and accelerates combustion. Simultaneously, it guides the return scavenging air, reduces residual exhaust gas in the combustion chamber 51, improves the air-fuel mixture quality, further reduces fuel consumption and emissions, accelerates the flow of intake and exhaust air, and improves scavenging efficiency.

[0044] In this embodiment, the air entering the casing 1 is heated by the heating grille 3. The heated air then enters the cylinder block 5 for scavenging and to mix with and ignite the fuel-air mixture ejected by the air-jet injector 74. The air-jet injector assembly 7 also heats the incoming compressed air via a heating plug, thereby intensifying the movement of the fuel-air mixture in the mixing chamber. This dual heating structure, combined with the unique curved surface design of the piston 6 top and its positional coordination with the air-jet injector 74 and spark plug 8, constitutes the combustion system of this invention, greatly improving fuel activity, atomization effect, ignition capability, combustion efficiency, and combustion stability.

[0045] This embodiment also discloses a heavy oil engine, including the above-described heavy oil engine combustion system.

[0046] It will be apparent to those skilled in the art that various modifications and variations can be made to the exemplary embodiments described above without departing from the spirit and scope of the invention. Therefore, it is intended that this invention cover modifications and variations falling within the scope of the appended claims and their equivalents.

Claims

1. A heavy oil engine combustion system, characterized in that, include: A casing, wherein an air inlet is provided on the casing; A reed valve mounting base is fixedly disposed with the air inlet; An intake pipe, which is mounted on the reed valve mounting base; A cylinder block is disposed on both sides of the casing. The cylinder block includes a combustion chamber located at the top of its inner cavity. A clump injector assembly and a spark plug are disposed at the top of the cylinder block. The piston is disposed in the cylinder body and can reciprocate along the axial direction of the cylinder body. The piston includes a combustion-promoting structure located at the top. The combustion-promoting structure includes, in radial order from the outside to the inside, an annular spherical part, a first annular recess, a first annular protrusion, a second annular recess, and a central boss.

2. The heavy oil engine combustion system as described in claim 1, characterized in that, The piston top is convex in shape. In a cross-section passing through the piston axis, the combustion-promoting structure is symmetrically arranged about the piston axis. The cross-section of the combustion-promoting structure on the left side of the axis is described as follows: the annular spherical part is an arc with its center at the bottom and extending upward; the first annular recess is an arc with its center at the top and extending upward; the first annular protrusion is an arc with its center at the bottom and protruding upward; and the second annular recess is an arc with its center at the top and concave downward.

3. The heavy oil engine combustion system as described in claim 2, characterized in that, The annular spherical part is tangentially connected to the first annular recess, the first annular protrusion is tangentially connected to the first annular recess, the first annular protrusion is tangentially connected to the second annular recess, and the second annular recess is tangentially connected to the central boss.

4. The heavy oil engine combustion system as described in claim 3, characterized in that, The center of the annular spherical part is located on the axis of the piston. The radius of the annular spherical part is R1, and the cylinder diameter is D. Then 2D≤R1≤3.5D. The radius of the first annular recess is R2. Then R2≥D. The second annular recess is set to correspond to the oil mist trajectory sprayed by the air-clamping injector assembly, and the tangent at the end of the second annular recess can intersect with the spark plug on the same side after it extends.

5. The heavy oil engine combustion system as described in claim 4, characterized in that, The upper surface of the central boss is a plane.

6. The heavy oil engine combustion system as described in claim 3, characterized in that, A heating grille is provided between the intake pipe and the reed valve mounting base. A throttle valve is integrated on the intake pipe, and a temperature sensor is provided on the throttle valve.

7. The heavy oil engine combustion system as described in claim 4, characterized in that, The air-clamping injector assembly includes a housing, a pressure regulating valve, an injector, and an air-clamping nozzle. The pressure regulating valve and the injector are located inside the housing, and the air-clamping nozzle is partially located inside the housing and partially extends out of the housing.

8. The heavy oil engine combustion system as described in claim 5, characterized in that, The outer casing includes an oil inlet, an air inlet, and a heating element. The air inlet is located at the end of the heating element, and the incoming air can be heated by the heating element.

9. The heavy oil engine combustion system as described in claim 6, characterized in that, The outer casing also includes a first mounting part and a second mounting part. The first mounting part is located away from the air inlet, and the second mounting part is located close to the air inlet. Both the first mounting part and the second mounting part are connected to the heating part and are internally interconnected. The first mounting part is equipped with a temperature sensor, and the second mounting part is equipped with a heating element.

10. The heavy oil engine combustion system as described in claim 7, characterized in that, The heating element extends into the heating section to heat the air entering the heating section, and the air temperature sensor extends into the heating section to detect the temperature of the heated air.

11. The heavy oil engine combustion system as described in claim 10, characterized in that, The air-clamping nozzle is located at the top of the cylinder block and on the central axis of the cylinder block, opposite to the central boss. The spark plug is arranged symmetrically about the air-clamping nozzle.

12. A heavy oil engine, characterized in that, The heavy oil engine combustion system includes any one of claims 1 to 1.

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