Dual-fuel injector, engine and control method of dual-fuel injector

Abstract

The invention relates to the technical field of engines, and particularly discloses a dual-fuel injector, an engine and a control method of the dual-fuel injector, and the dual-fuel injector comprises a fuel oil supply channel, a fuel gas supply channel and a fuel injection part. Wherein the fuel oil supply channel is used for conveying fuel oil, the fuel gas supply channel is used for conveying fuel gas, the fuel injection part is used for communicating with the combustion chamber, the fuel injection part can selectively communicate with the fuel oil supply channel, and the fuel injection part can also selectively communicate with the fuel gas supply channel; therefore, fuel oil and fuel gas are injected into the combustion chamber through the fuel injection part, when the fuel gas passes through the fuel injection part, the fuel oil in the fuel injection part can be scoured, the fuel oil is brought into the combustion chamber so as to improve the fuel utilization rate of the fuel oil, the fuel injection part is prevented from storing the fuel oil and being carbonized, and the heat efficiency and emission of the engine are guaranteed; in addition, fuel gas and fuel oil are injected into the combustion chamber through the fuel injection part, and the atomization effect and the ignition effect of diesel oil can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a dual-fuel injector, an engine and a control method for the dual-fuel injector. Background Art

[0002] Some existing engines use a single fuel, while others use dual fuels. Taking a dual fuel engine as an example, the fuel supply method of a dual fuel engine is to inject gas (such as natural gas) directly into the combustion chamber through a dual fuel injector, and use a pilot amount of liquid fuel (such as diesel) to trigger the combustion of gas fuel to drive the engine, which can effectively improve the engine's power, economy and emissions.

[0003] The existing dual-fuel injector disclosed in the previous patent with application number CN202020447532.0 includes an injector body, an injection needle valve and an injection valve needle. The injector body has a first injection part (for injecting natural gas) and a second injection part (for injecting diesel), the injection needle valve is used to close or open the first injection part, and the injection valve needle is used to close or open the second injection part. The following problems exist in this injector:

[0004] 1) Diesel and natural gas injection are independent of each other. Limited by the current injection technology level, the injection rail pressure of diesel is relatively low. In order to avoid diesel injection onto the bottom surface of the cylinder head, the injector is extended into the combustion chamber with a large size. Diesel is prone to coking and carbon deposition at high temperatures. After the engine runs for a long time, the hole of the second injection part is blocked, resulting in poor combustion, thermal efficiency and emissions.

[0005] 2) The two-row design with the first injection part and the second injection part separated by a distance, the natural gas is at a large distance from the diesel flame after being sprayed out, and due to the low injection rail pressure of the diesel, the atomization effect of the diesel is poor, resulting in a poor ignition effect.

[0006] Therefore, there is an urgent need for a dual fuel injector and an engine to solve the above problems. Summary of the invention

[0007] The purpose of the present invention is to provide a dual-fuel injector, an engine and a control method for the dual-fuel injector to solve the problem that the spray holes of the existing dual-fuel injectors are prone to carbon deposits, which affects the operation effect of the engine.

[0008] In a first aspect, the present invention provides a dual fuel injector, the dual fuel injector comprising:

[0009] It includes a fuel supply channel and a gas supply channel, the fuel supply channel is used to transport fuel, and the gas supply channel is used to transport gas. It is characterized in that the dual-fuel injector also includes a fuel injection part, the fuel injection part is used to communicate with the combustion chamber, the fuel injection part can be selectively connected with the fuel supply channel, and the fuel injection part can also be selectively connected with the gas supply channel.

[0010] As a preferred technical solution for a dual fuel injector, the fuel injection portion includes a steady flow chamber and a fuel injection hole. The steady flow chamber can be selectively connected to the fuel supply channel, and the steady flow chamber can also be selectively connected to the gas supply channel. The steady flow chamber is connected to one end of the fuel injection hole, and the other end of the fuel injection hole is used to communicate with the combustion chamber.

[0011] As a preferred technical solution for a dual-fuel injector, the steady flow chamber includes a first steady flow chamber, a second steady flow chamber, and an oil injection hole connecting the first steady flow chamber and the second steady flow chamber, the first steady flow chamber is selectively connected to the fuel supply channel, the second steady flow chamber is selectively connected to the gas supply channel, the second steady flow chamber surrounds the outer circumference of the first steady flow chamber, and the center line of the second steady flow chamber coincides with the center line of the first steady flow chamber.

[0012] As a preferred technical solution of the dual-fuel injector, the fuel injection hole is opened horizontally, and the fuel injection hole is located above the fuel injection hole.

[0013] As a preferred technical solution of the dual-fuel injector, the dual-fuel injector comprises a plurality of the fuel injection holes, and the plurality of the fuel injection holes are evenly distributed along the circumference of the second stabilizing flow cavity;

[0014] The flow stabilizing cavity includes a plurality of oil injection holes, and the plurality of oil injection holes are evenly distributed along the circumference of the first flow stabilizing cavity.

[0015] As a preferred technical solution for the dual-fuel injector, the injection hole is close to the top of the second stabilizing chamber and away from the bottom of the second stabilizing chamber, and the coverage area of ​​the fuel injected by the multiple injection holes can cover the entire cavity wall of the second stabilizing chamber.

[0016] As a preferred technical solution of the dual-fuel injector, the dual-fuel injector comprises a first valve body, a second valve body and a shell, the second valve body is slidably disposed in the shell, the first valve body is slidably disposed in the second valve body, the second valve body and the inner surface of the shell are enclosed to form the gas supply channel, and the first valve body and the second valve body are enclosed to form the fuel supply channel;

[0017] The first stabilizing chamber is provided in the second valve body, and the first stabilizing chamber and the fuel supply passage are communicated through a first opening. The first valve body can slide relative to the second valve body and has a first open position and a first closed position. When the first valve body is located at the first closed position, the first valve body closes the first opening. When the first valve body is located at the first open position, the first valve body opens the first opening.

[0018] The second stabilizing flow chamber is arranged in the outer shell, and the second stabilizing flow chamber and the gas supply channel are connected through a second opening. The second valve body can slide relative to the outer shell and has a second open position and a second closed position. When the second valve body is located at the second closed position, the second valve body closes the second opening; when the second valve body is located at the second open position, the second valve body opens the second opening.

[0019] As a preferred technical solution of the dual fuel injector, the bottom surface of the cylinder head is located between the fuel injection hole and the oil injection hole.

[0020] The dual fuel injector provided by the present invention has at least the following beneficial effects:

[0021] The dual fuel injector includes a fuel supply channel, a gas supply channel and a fuel injection unit. The fuel supply channel is used to transport fuel, the gas supply channel is used to transport gas, the fuel injection unit is used to communicate with the combustion chamber, the fuel injection unit can selectively communicate with the fuel supply channel, and the fuel injection unit can also selectively communicate with the gas supply channel. In the dual fuel injector, both fuel and gas are injected into the combustion chamber through the fuel injection unit. When the gas passes through the fuel injection unit, it can flush the fuel therein and bring the fuel therein into the combustion chamber for combustion, thereby improving the fuel utilization rate of the fuel, avoiding the presence of fuel in the fuel injection unit, and further avoiding the carbonization of the fuel in the fuel injection unit, thereby ensuring the thermal efficiency and emissions of the engine; in addition, both gas and fuel are injected into the combustion chamber through the fuel injection unit, which can ensure the atomization effect and ignition effect of the diesel.

[0022] In a second aspect, the present invention provides an engine, comprising the dual-fuel injector of any of the above-mentioned schemes, the engine also comprising a cylinder block, a cylinder head and a piston, the piston being slidably located in the cylinder block, the cylinder head being covered on the cylinder block, when the piston runs to the top dead center, a combustion chamber is enclosed between the top surface of the piston and the bottom surface of the cylinder head, the dual-fuel injector is penetrated through the cylinder head, and the bottom end of the dual-fuel injector extends into the combustion chamber, and the fuel injection part is connected to the combustion chamber.

[0023] The engine provided by the present invention has at least the following beneficial effects:

[0024] The engine includes the above dual-fuel injector, and also includes a cylinder body, a cylinder head and a piston. The piston is slidably located in the cylinder body, and the cylinder head is arranged on the cylinder body. When the piston runs to the top dead center, a combustion chamber is formed between the top surface of the piston and the bottom surface of the cylinder head. The dual-fuel injector is penetrated through the cylinder head, and the bottom end of the dual-fuel injector extends into the combustion chamber, and the fuel injection part is connected to the combustion chamber. The engine adopts the above dual-fuel injector, which can effectively avoid carbonization and coking of fuel in the dual-fuel injector, and ensure the reliability and stability of engine operation.

[0025] In a third aspect, the present invention provides a dual-fuel injector control method, which is implemented by the dual-fuel injector in any of the above schemes, and the dual-fuel injector control method includes a fuel priority injection control method, a gas priority injection method and a dual-fuel synchronous injection control method;

[0026] The fuel priority injection control method comprises: firstly connecting the fuel supply passage with the fuel injection part and disconnecting the gas supply passage from the fuel injection part, and the fuel injection part injects fuel into the combustion chamber; then disconnecting the fuel supply passage from the fuel injection part and connecting the gas supply passage with the fuel injection part, and the fuel injection part injects gas into the combustion chamber;

[0027] The gas priority injection control method comprises: firstly disconnecting the fuel supply passage from the fuel injection unit and connecting the fuel supply passage to the fuel injection unit, and the fuel injection unit injects fuel into the combustion chamber; then connecting the fuel supply passage to the fuel injection unit and disconnecting the fuel supply passage from the fuel injection unit, and the fuel injection unit injects fuel into the combustion chamber;

[0028] The dual-fuel synchronous injection control method includes: first connecting the fuel supply channel with the fuel injection unit, and connecting the gas supply channel with the fuel injection unit, the fuel injection unit simultaneously injects gas and fuel into the combustion chamber, and then disconnecting the fuel supply channel from the fuel injection unit, and disconnecting the gas supply channel from the fuel injection unit.

[0029] The control method of the dual-fuel injector provided by the present invention has at least the following beneficial effects:

[0030] The control method of the dual-fuel injector includes a fuel priority injection control method, a gas priority injection method and a dual-fuel synchronous injection control method, wherein in the fuel priority injection control method, the fuel is injected before the gas, and part of the first injected fuel will remain in the fuel injection part, and the fuel remaining in the fuel injection part can be flushed into the combustion chamber by the later injected gas, so as to avoid fuel carbonization and coking, and improve the utilization rate of the fuel; in the gas priority injection method, the gas is injected before the fuel, and part of the first injected gas will remain in the fuel injection part, and the fuel remaining in the fuel injection part can be brought into the combustion chamber by the later injected fuel, so as to improve the utilization rate of the gas; in the synchronous injection control method, the fuel and the gas are injected synchronously, and because the injection rail pressure of the gas is greater than the injection rail pressure of the fuel, the fuel entering the fuel injection part shares the injection rail pressure of the gas, and the atomization will be more sufficient after being injected into the combustion chamber, and the fuel and the gas are synchronously injected into the combustion chamber from the same fuel injection hole, and the ignition effect of the fuel is also optimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the first structure of the dual-fuel injector in an embodiment of the present invention (the first valve body is located at the first closed position, and the second valve body is located at the second closed position);

[0032] Figure 2 Schematic diagram of the second structure of the dual-fuel injector in the embodiment of the present invention (the first valve body is located at the first open position, and the second valve body is located at the second closed position);

[0033] Figure 3 Schematic diagram of the third structure of the dual-fuel injector in the embodiment of the present invention (the first valve body is located at the first closed position, and the second valve body is located at the second open position);

[0034] Figure 4 Schematic diagram of the fourth structure of the dual-fuel injector in an embodiment of the present invention (the first valve body is located at the first open position, and the second valve body is located at the second open position).

[0035] In the figure:

[0036] 1. Fuel supply channel; 2. Gas supply channel;

[0037] 3. fuel injection part; 31. fuel injection hole; 32. flow stabilizing cavity; 321. first flow stabilizing cavity; 322. second flow stabilizing cavity; 323. fuel injection hole;

[0038] 4. First opening; 5. Second opening;

[0039] 10. First valve body; 20. Second valve body; 30. Housing. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations 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" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0042] 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 according to specific circumstances.

[0043] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0044] The existing injector includes an injector body, an injection needle valve and an injection valve needle. The injector body has a first injection part and a second injection part. The injection needle valve is used to close or open the first injection part, and the injection valve needle is used to close or open the second injection part. In this injector, the injection of diesel and natural gas are independent of each other. Limited by the current injection technology level, the injection rail pressure of diesel is relatively low, and in order to avoid diesel being sprayed onto the bottom surface of the cylinder head, the injector extends into the combustion chamber with a large size. Diesel is prone to coking and carbon deposition at high temperatures. After the engine runs for a long time, the hole of the second injection part is blocked, resulting in poor combustion, thermal efficiency and emissions. In addition, the two-row design with the first injection part and the second injection part separated by a distance makes the natural gas flame far away from the diesel after being sprayed out, and limited by the low injection rail pressure of diesel, the atomization effect of diesel is poor, resulting in poor ignition effect.

[0045] In this regard, this embodiment provides a dual fuel injector to solve the above problems.

[0046] Please refer to Figures 1 to 4 The dual fuel injector includes a fuel supply channel 1, a gas supply channel 2 and a fuel injection unit 3. The fuel supply channel 1 is used to deliver fuel (such as diesel), the gas supply channel 2 is used to deliver gas (such as natural gas), and the fuel injection unit 3 is used to communicate with the combustion chamber. The fuel injection unit 3 can selectively communicate with the fuel supply channel 1, and the fuel injection unit 3 can also selectively communicate with the gas supply channel 2. In this way, both fuel and gas are injected into the combustion chamber through the fuel injection unit 3. When the gas passes through the fuel injection unit 3, it can flush the fuel therein and bring the fuel therein into the combustion chamber for combustion, thereby improving the fuel utilization rate of the fuel, avoiding the presence of fuel in the fuel injection unit 3, and further avoiding the carbonization of the fuel in the fuel injection unit 3, thereby ensuring the thermal efficiency and emission of the engine; in addition, both gas and fuel are injected into the combustion chamber through the fuel injection unit 3, and there is no gap after injection into the combustion chamber, which can ensure the atomization effect and ignition effect of the diesel.

[0047] It should be noted that natural gas will not coke at high temperatures and will not cause carbon deposition in the fuel injection portion 3 .

[0048] Optionally, the fuel injection part 3 includes a flow stabilizing chamber 32 and a fuel injection hole 31. The flow stabilizing chamber 32 can be selectively connected to the fuel supply channel 1, and the flow stabilizing chamber 32 can also be selectively connected to the gas supply channel 2. The flow stabilizing chamber 32 is connected to one end of the fuel injection hole 31, and the other end of the fuel injection hole 31 is used to communicate with the combustion chamber. After the fuel and gas enter the flow stabilizing chamber 32, the flow rate of the fuel and gas entering the fuel injection hole 31 can be stabilized by the flow stabilizing chamber 32, thereby ensuring that the fuel and gas are sprayed into the combustion chamber at a stable flow rate to ensure sufficient combustion; in addition, by stabilizing the flow rate of the gas through the flow stabilizing chamber 32, it can be ensured that the gas flushes the fuel in the fuel injection hole 31 at a stable flow rate, ensuring a stable flushing effect.

[0049] Optionally, the steady flow chamber 32 includes a first steady flow chamber 321, a second steady flow chamber 322 and an oil injection hole 323 connecting the first steady flow chamber 321 and the second steady flow chamber 322, the first steady flow chamber 321 is selectively connected to the fuel supply channel 1, the second steady flow chamber 322 is selectively connected to the gas supply channel 2, the second steady flow chamber 322 surrounds the outer circumference of the first steady flow chamber 321, and the center line of the second steady flow chamber 322 coincides with the center line of the first steady flow chamber 321. With such arrangement, on the one hand, after the fuel passes through the first steady flow chamber 321 for steady flow, it enters the second steady flow chamber 322 with a stable flow rate, and can further stabilize the flow through the second steady flow chamber 322, thereby ensuring the steady flow effect on the fuel; on the other hand, isolation through the first steady flow chamber 321 can prevent the gas from mixing into the fuel supply channel 1; on the other hand, when the fuel is sprayed into the combustion chamber, when the fuel is sprayed before the gas, the fuel in the second steady flow chamber 322 and the fuel injection hole 31 can be flushed by the gas, thereby preventing the fuel from carbonizing and coking in the second steady flow chamber 322 and the fuel injection hole 31; when the fuel is sprayed after the gas, the gas remaining in the second steady flow chamber 322 can be brought into the combustion chamber by the fuel, thereby ensuring the fuel utilization rate of the gas; when the fuel and the gas are sprayed at the same time, after the fuel enters the second steady flow chamber 322, it can be fully mixed with the gas, thereby improving the mixing uniformity of the gas and fuel entering the combustion chamber, thereby improving the ignition effect.

[0050] It should be noted that when the fuel is sprayed into the combustion chamber, when the fuel is sprayed after the gas, when the fuel is sprayed into the combustion chamber twice adjacently, the gas injected in the latter time can flush the fuel remaining in the second stabilizing chamber 322 and the fuel injection hole 31 from the previous injection, which can also prevent the fuel from carbonizing and coking in the second stabilizing chamber 322 and the fuel injection hole 31; similarly, when the fuel is sprayed before the gas, when the fuel is sprayed into the combustion chamber twice adjacently, the fuel injected in the latter time can bring the gas remaining in the second stabilizing chamber 322 and the fuel injection hole 31 from the previous injection into the combustion chamber.

[0051] In addition, the injection rail pressure of the gas is greater than the injection rail pressure of the fuel. When the fuel and the gas are injected at the same time, after the fuel enters the second flow stabilizing cavity 322, it will share the injection pressure of the gas, thereby improving the atomization effect and the ignition effect.

[0052] Optionally, the flow stabilizing chamber 32 includes a plurality of injection holes 323, and the plurality of injection holes 323 are evenly distributed along the circumference of the first flow stabilizing chamber 321. This ensures that the fuel is evenly sprayed into the second flow stabilizing chamber 322. In this embodiment, the first flow stabilizing chamber 321 is hemispherical.

[0053] Optionally, the dual fuel injector includes a plurality of fuel injection holes 31, which are evenly distributed along the circumference of the second flow stabilization cavity 322, so as to ensure that the gas and fuel are evenly sprayed into the combustion chamber. In this embodiment, the second flow stabilization cavity 322 is hemispherical.

[0054] Optionally, the bottom surface of the cylinder head is located between the fuel injection hole 31 and the oil injection hole 323. Figure 1 As shown in S in the figure, the distance between the bottom surface of the cylinder head and the bottom end of the fuel injection hole 31 is H. Compared with the dual-fuel injector in the prior art, it is necessary to arrange the injection part for injecting fuel and gas in the combustion chamber at the same time. In this embodiment, since both fuel and gas are injected into the combustion chamber through the same gas injection hole, compared with the prior art, the value of H can be effectively reduced, thereby reducing the contact area between the dual-fuel injector and the high-temperature gas in the combustion chamber, reducing the temperature of the dual-fuel injector, and avoiding carbonization and coking of the fuel in the dual-fuel injector.

[0055] Optionally, the fuel injection hole 323 is opened horizontally, and the fuel injection hole 323 is located above the fuel injection hole 31. In this way, after the fuel enters the second stabilizing chamber 322, the gas in the second stabilizing chamber 322 can be brought into the combustion chamber from top to bottom.

[0056] Optionally, the fuel injection hole 31 is opened obliquely downward, that is, the injection direction of the fuel injection hole 31 is set at an angle with the vertical plane. Specifically, the angle between the injection direction of the fuel injection hole 31 and the vertical plane can be determined by the shape of the combustion chamber.

[0057] Optionally, the fuel injection holes 323 are close to the top of the second stabilizing chamber 322 and away from the bottom of the second stabilizing chamber 322, and the coverage of the fuel injected by the multiple fuel injection holes 323 can cover the entire cavity wall of the second stabilizing chamber 322. This arrangement can ensure that after the fuel enters the second stabilizing chamber 322, it can bring the gas in the entire second stabilizing chamber 322 into the combustion chamber from top to bottom, thereby fully improving the combustion efficiency of the gas.

[0058] Optionally, the dual fuel injector includes a first valve body 10, a second valve body 20 and an outer shell 30, the second valve body 20 is slidably disposed in the outer shell 30, the first valve body 10 is slidably disposed in the second valve body 20, a gas supply channel 2 is enclosed between the inner surfaces of the second valve body 20 and the outer shell 30, and a fuel supply channel 1 is enclosed between the first valve body 10 and the second valve body 20.

[0059] The first steady flow chamber 321 is disposed in the second valve body 20, and the first steady flow chamber 321 and the fuel supply channel 1 are connected through the first opening 4. The first valve body 10 can slide relative to the second valve body 20 and has a first open position and a first closed position. Figure 1 and Figure 3 As shown, when the first valve body 10 is located at the first closed position, the first valve body 10 closes the first opening 4, and the fuel supply channel 1 cannot supply fuel to the first steady flow chamber 321; Figure 2 and Figure 4 As shown, when the first valve body 10 is located at the first open position, the first valve body 10 opens the first opening 4, and the fuel provided by the fuel supply channel 1 can enter the first stabilizing chamber 321 through the first opening 4. Specifically, in this embodiment, when the first valve body 10 is located at the first closed position, the first valve body 10 partially extends into the first stabilizing chamber 321 and is sealed with the edge of the first opening 4, so that the fuel supply channel 1 and the first stabilizing chamber 321 are separated.

[0060] The second flow stabilizing chamber 322 is disposed in the housing 30, and the second flow stabilizing chamber 322 and the gas supply channel 2 are connected through the second opening 5. The second valve body 20 can slide relative to the housing 30 and has a second open position and a second closed position. Figure 1 and Figure 2 As shown, when the second valve body 20 is located at the second closed position, the second valve body 20 closes the second opening 5, and the gas provided by the gas supply channel 2 cannot enter the second flow stabilizing chamber 322 through the second opening 5; Figure 3 and Figure 4 As shown, when the second valve body 20 is located at the second open position, the second valve body 20 opens the second opening 5, and the gas provided by the gas supply channel 2 can enter the second flow stabilizing chamber 322 through the second opening 5. Specifically, in this embodiment, when the second valve body 20 is located at the second closed position, the second valve body 20 partially extends into the second flow stabilizing chamber 322 and is sealed with the edge of the second opening 5, so as to separate the gas supply channel 2 from the second flow stabilizing chamber 322.

[0061] Optionally, when the second valve body 20 opens the second opening 5 , the oil injection hole 323 is flush with the top of the second stabilizing flow chamber 322 , thereby ensuring the effect of the fuel oil carrying the gas in the second stabilizing flow chamber 322 .

[0062] This embodiment also provides an engine, which includes the above-mentioned dual-fuel injector, and the engine also includes a cylinder body, a cylinder head and a piston. The piston slides in the cylinder body, and the cylinder head is arranged on the cylinder body. When the piston runs to the top dead center, a combustion chamber is formed between the top surface of the piston and the bottom surface of the cylinder head. The dual-fuel injector is penetrated through the cylinder head, and the bottom end of the dual-fuel injector extends into the combustion chamber, and the fuel injection part 3 is connected to the combustion chamber. Among them, the piston moves in the cylinder body, and the position at the highest point reached by the top surface of the piston is called the top dead center. At this time, the top surface of the piston is farthest from the rotation center of the crankshaft. The engine adopts the above-mentioned dual-fuel injector, which can effectively avoid carbonization and coking of fuel in the dual-fuel injector, and ensure the reliability and stability of the engine operation.

[0063] The present embodiment further provides a control method for a dual fuel injector, and the control method for a dual fuel injector is implemented by the dual fuel injector.

[0064] Specifically, the control method of the dual fuel injector includes a fuel oil priority injection control method, a gas priority injection method and a dual fuel synchronous injection control method.

[0065] The fuel priority injection control method includes: firstly connecting the fuel supply channel 1 with the fuel injection unit 3, and disconnecting the gas supply channel 2 from the fuel injection unit 3, and the fuel injection unit 3 injects fuel into the combustion chamber; then disconnecting the fuel supply channel 1 from the fuel injection unit 3, and connecting the gas supply channel 2 to the fuel injection unit 3, and the fuel injection unit 3 injects gas into the combustion chamber. For details, please refer to Figure 1 Before the fuel needs to be injected into the combustion chamber, the first valve body 10 is located at the first closed position, and the second valve body 20 is located at the second closed position. At this time, the fuel supply channel 1 and the gas supply channel 2 are disconnected from the fuel injection part 3; then refer to Figure 2 , the first valve body 10 is switched to the first open position, the second valve body 20 is still kept in the second closed position, only the fuel supply channel 1 and the fuel injection part 3 are connected, the fuel supplied by the fuel supply channel 1 enters the first stabilizing chamber 321 through the first opening 4, then enters the second stabilizing chamber 322 through the injection hole 323, and then is injected into the combustion chamber through the fuel injection hole 31. When the fuel injection time is reached, then refer to Figure 3 , the first valve body 10 is switched to the first closed position, the second valve body 20 is switched to the second open position, only the gas supply channel 2 and the fuel injection part 3 are connected, the gas supplied by the gas supply channel 2 passes through the second opening 5 and enters the second flow stabilizing cavity 322, and then is injected into the combustion chamber through the fuel injection hole 31. When the injection time of the gas is reached, please refer to Figure 1, the first valve body 10 remains in the first closed position, and the second valve body 20 switches to the second closed position. In the fuel priority injection control method, part of the first injected fuel will remain in the cavity wall of the second stabilizing cavity 322 and the fuel injection hole 31, and the fuel remaining in the cavity wall of the second stabilizing cavity 322 and the fuel injection hole 31 can be flushed into the combustion chamber by the later injected fuel gas to avoid fuel carbonization and coking, and improve the utilization rate of fuel. In the process of two adjacent injections, the fuel injected in the later injection can bring the fuel remaining in the second stabilizing cavity 322 and the fuel injection hole 31 after the previous injection into the combustion chamber to improve the utilization rate of fuel.

[0066] The gas priority injection control method includes: firstly disconnecting the fuel supply channel 1 from the fuel injection unit 3 and connecting the gas supply channel 2 to the fuel injection unit 3, and the fuel injection unit 3 injects fuel into the combustion chamber; then connecting the fuel supply channel 1 to the fuel injection unit 3 and disconnecting the gas supply channel 2 from the fuel injection unit 3, and the fuel injection unit 3 injects fuel into the combustion chamber. For details, please refer to Figure 1 Before the fuel needs to be injected into the combustion chamber, the first valve body 10 is located at the first closed position, and the second valve body 20 is located at the second closed position. At this time, the fuel supply channel 1 and the gas supply channel 2 are disconnected from the fuel injection part 3; then refer to Figure 3 Only the gas supply channel 2 is connected to the fuel injection part 3, the gas supplied by the gas supply channel 2 enters the second flow stabilizing cavity 322 through the second opening 5, and then is injected into the combustion chamber through the fuel injection hole 31. When the injection time of the gas is reached, then refer to Figure 2 , the first valve body 10 is switched to the first open position, the second valve body 20 is switched to the second closed position, only the fuel supply channel 1 and the fuel injection part 3 are connected, the fuel supplied by the fuel supply channel 1 enters the first stabilizing chamber 321 through the first opening 4, then enters the second stabilizing chamber 322 through the injection hole 323, and then is injected into the combustion chamber through the fuel injection hole 31. When the fuel injection time is reached, refer to Figure 1 , so that the first valve body 10 switches to the first closed position, and the second valve body 20 remains in the second closed position. In the gas priority injection control method, part of the first injected gas will remain in the second stabilizing chamber 322 and the fuel injection hole 31, and the fuel injected later can bring the remaining fuel in the second stabilizing chamber 322 and the fuel injection hole 31 into the combustion chamber to improve the utilization rate of the gas, and in the two adjacent injection processes, the gas injected later can flush the fuel remaining in the cavity wall of the second stabilizing chamber 322 and the fuel injection hole 31 after the first injection into the combustion chamber to avoid fuel carbonization and coking.

[0067] The dual-fuel synchronous injection control method includes: firstly connecting the fuel supply channel 1 with the fuel injection unit 3, and connecting the gas supply channel 2 with the fuel injection unit 3, and the fuel injection unit 3 simultaneously injects gas and fuel into the combustion chamber, and then disconnecting the fuel supply channel 1 from the fuel injection unit 3, and disconnecting the gas supply channel 2 from the fuel injection unit 3. For details, please refer to Figure 1 Before the fuel needs to be injected into the combustion chamber, the first valve body 10 is located at the first closed position, and the second valve body 20 is located at the second closed position. At this time, the fuel supply channel 1 and the gas supply channel 2 are disconnected from the fuel injection part 3; then refer to Figure 4 The fuel supply channel 1 and the gas supply channel 2 are both connected to the fuel injection part 3. The fuel supplied by the fuel supply channel 1 enters the first steady flow chamber 321 through the first opening 4, and then enters the second steady flow chamber 322 through the fuel injection hole 323. The gas supplied by the gas supply channel 2 enters the second steady flow chamber 322 through the second opening 5. The gas and the fuel are fully mixed in the second steady flow chamber 322 and are jointly injected into the combustion chamber through the fuel injection hole 31. Since the injection rail pressure of the gas is greater than the injection rail pressure of the fuel, the fuel entering the second steady flow chamber 322 shares the injection rail pressure of the gas, and the atomization will be more sufficient after being injected into the combustion chamber. In addition, the fuel and the gas are synchronously injected into the combustion chamber from the same fuel injection hole 31, and the ignition effect of the fuel is also optimal. When the injection time of the gas and the fuel is reached, refer to Figure 1 , the first valve body 10 is switched to the first closed position, the second valve body 20 is switched to the second closed position, and the fuel supply channel 1 and the gas supply channel 2 are disconnected from the fuel injection part 3.

[0068] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A dual fuel injector, comprising a fuel supply channel (1) and a gas supply channel (2), wherein the fuel supply channel (1) is used to deliver fuel, and the gas supply channel (2) is used to deliver gas, characterized in that: The dual fuel injector further comprises a fuel injection portion (3), wherein the fuel injection portion (3) is used to communicate with the combustion chamber, the fuel injection portion (3) can selectively communicate with the fuel oil supply passage (1), and the fuel injection portion (3) can also selectively communicate with the fuel gas supply passage (2).

2. The dual fuel injector according to claim 1, characterized in that: The fuel injection portion (3) comprises a flow stabilizing chamber (32) and a fuel injection hole (31); the flow stabilizing chamber (32) can be selectively connected to the fuel supply channel (1), and the flow stabilizing chamber (32) can also be selectively connected to the gas supply channel (2); the flow stabilizing chamber (32) is connected to one end of the fuel injection hole (31), and the other end of the fuel injection hole (31) is used to communicate with the combustion chamber.

3. The dual fuel injector according to claim 2, characterized in that: The flow stabilizing chamber (32) comprises a first flow stabilizing chamber (321), a second flow stabilizing chamber (322), and an oil injection hole (323) connecting the first flow stabilizing chamber (321) and the second flow stabilizing chamber (322); the first flow stabilizing chamber (321) is selectively connected to the fuel supply channel (1); the second flow stabilizing chamber (322) is selectively connected to the gas supply channel (2); the second flow stabilizing chamber (322) surrounds the outer periphery of the first flow stabilizing chamber (321), and the center line of the second flow stabilizing chamber (322) coincides with the center line of the first flow stabilizing chamber (321).

4. The dual fuel injector according to claim 3, characterized in that The oil injection hole (323) is opened horizontally, and the oil injection hole (323) is located above the fuel injection hole (31).

5. The dual fuel injector according to claim 3, characterized in that The dual-fuel injector comprises a plurality of fuel injection holes (31), and the plurality of fuel injection holes (31) are evenly distributed along the circumference of the second stabilizing cavity (322); The flow stabilizing chamber (32) comprises a plurality of oil injection holes (323), and the plurality of oil injection holes (323) are evenly distributed along the circumference of the first flow stabilizing chamber (321).

6. The dual fuel injector according to claim 5, characterized in that The fuel injection holes (323) are close to the top end of the second stabilizing chamber (322) and away from the bottom end of the second stabilizing chamber (322), and the coverage area of ​​the fuel injected by the multiple fuel injection holes (323) can cover the entire cavity wall of the second stabilizing chamber (322).

7. The dual fuel injector according to claim 3, characterized in that The dual-fuel injector comprises a first valve body (10), a second valve body (20) and a housing (30); the second valve body (20) is slidably disposed in the housing (30); the first valve body (10) is slidably disposed in the second valve body (20); the second valve body (20) and the inner surface of the housing (30) are enclosed to form the gas supply passage (2); and the first valve body (10) and the second valve body (20) are enclosed to form the fuel supply passage (1); The first stabilizing chamber (321) is arranged on the second valve body (20), and the first stabilizing chamber (321) and the fuel supply channel (1) are connected via a first opening (4); the first valve body (10) can slide relative to the second valve body (20) and has a first open position and a first closed position; when the first valve body (10) is located at the first closed position, the first valve body (10) closes the first opening (4); when the first valve body (10) is located at the first open position, the first valve body (10) opens the first opening (4); The second stabilizing chamber (322) is arranged on the shell (30), and the second stabilizing chamber (322) and the gas supply channel (2) are connected through a second opening (5); the second valve body (20) can slide relative to the shell (30) and has a second open position and a second closed position; when the second valve body (20) is located at the second closed position, the second valve body (20) closes the second opening (5); when the second valve body (20) is located at the second open position, the second valve body (20) opens the second opening (5).

8. The dual fuel injector according to any one of claims 3 to 7, characterized in that: The bottom surface of the cylinder head is located between the fuel injection hole (31) and the oil injection hole (323).

9. An engine, characterized in that: The dual-fuel injector comprises the dual-fuel injector as described in any one of claims 1 to 8, and the engine further comprises a cylinder block, a cylinder head and a piston, wherein the piston is slidably located in the cylinder block, and the cylinder head is covered on the cylinder block, and when the piston runs to the top dead center, a combustion chamber is enclosed between the top surface of the piston and the bottom surface of the cylinder head, the dual-fuel injector is penetrated through the cylinder head, and the bottom end of the dual-fuel injector extends into the combustion chamber, and the fuel injection part (3) is connected to the combustion chamber.

10. A control method for a dual fuel injector, characterized in that: The dual-fuel injector according to any one of claims 1 to 8 is implemented, wherein the control method of the dual-fuel injector includes a fuel priority injection control method, a gas priority injection method and a dual-fuel synchronous injection control method; The fuel priority injection control method comprises: firstly connecting the fuel supply passage (1) with the fuel injection unit (3) and disconnecting the gas supply passage (2) from the fuel injection unit (3), and the fuel injection unit (3) injects fuel into the combustion chamber; then disconnecting the fuel supply passage (1) from the fuel injection unit (3) and connecting the gas supply passage (2) with the fuel injection unit (3), and the fuel injection unit (3) injects gas into the combustion chamber; The gas priority injection control method comprises: firstly disconnecting the fuel supply channel (1) from the fuel injection unit (3) and connecting the fuel supply channel (2) to the fuel injection unit (3), and the fuel injection unit (3) injects fuel gas into the combustion chamber; then connecting the fuel supply channel (1) to the fuel injection unit (3) and disconnecting the fuel supply channel (2) from the fuel injection unit (3), and the fuel injection unit (3) injects fuel into the combustion chamber; The dual-fuel synchronous injection control method comprises: firstly connecting the fuel supply channel (1) with the fuel injection unit (3), and connecting the gas supply channel (2) with the fuel injection unit (3), and the fuel injection unit (3) injecting gas and fuel into the combustion chamber simultaneously; and then disconnecting the fuel supply channel (1) from the fuel injection unit (3), and disconnecting the gas supply channel (2) from the fuel injection unit (3).

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