Low-carbon zero-carbon fuel injector assembly

Abstract

The invention discloses a low-carbon zero-carbon fuel injector assembly which is unique in structure and comprises an injector body, a valve assembly and a nozzle matching part. The ejector is provided with a control oil inlet connector and a low-carbon / zero-carbon fuel inlet connector, and separation of control oil and main fuel is achieved. The oil return interface is independently controlled; control oil enters the valve seat through an oil way and is led to an upper annular cavity and a control cavity of the nozzle valve body through a control branch oil way and a control oil way on the valve plate respectively. The control cavity is connected with an oil return path through an oil return hole and a normally-closed ball valve, and circulation of control oil is achieved. The low-carbon / zero-carbon fuel enters the valve seat through the oil inlet path, enters the oil containing groove of the nozzle valve body through the main fuel oil channel hole in the valve plate, and is injected into an engine combustion chamber after the needle valve is lifted up. According to the design, a medium with low saturated vapor pressure can be adopted for the control oil way, cavitation erosion is avoided, one-way leakage between the control oil way and the main fuel oil way is achieved through a unique structure, the control oil way is effectively prevented from being diluted and polluted, and stable and reliable injection is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of engine injectors, and in particular relates to a low-carbon or zero-carbon fuel injector assembly. Background Art

[0002] In the field of modern transportation and industry, heavy-duty and ultra-heavy-duty engines are core power equipment, and their fuel selection has a vital impact on energy efficiency and environmental protection. Traditionally, such engines mainly rely on diesel or heavy oil as energy. However, these fossil fuels are not only non-renewable resources and face the risk of increasing depletion, but also the large amount of carbon emissions generated during their combustion process has become one of the main drivers of global climate change and environmental pollution.

[0003] With the increasing global awareness of sustainable development and environmental protection, as well as the clear requirements for reducing carbon emissions at the national level, it is particularly urgent to find and promote the use of renewable, low-carbon alternative fuels. In this context, new low-carbon and zero-carbon fuels such as methanol, ammonia, dimethyl ether, hydrogen and natural gas have gradually become a hot spot for research and application due to their clean, renewable or low-carbon emission characteristics.

[0004] However, despite the significant advantages of these low-carbon fuels in terms of environmental protection and energy sustainability, they face a series of technical challenges when actually applied to conventional common rail injectors for heavy-duty and ultra-heavy-duty engines. Specifically, because these fuels are often highly corrosive and have high saturated vapor pressures, the moving parts inside the injector (such as valve ports, needle valves, etc.) are very susceptible to cavitation after long-term operation. Cavitation not only causes the performance of the injector to decline and shortens its service life, but in severe cases it can even cause the injector to fail to work properly, thereby affecting the stable operation and power output of the engine.

[0005] Therefore, in view of the cavitation problem existing in the common rail injectors in the prior art when injecting low-carbon and zero-carbon fuels, there is an urgent need to develop an injector assembly that can adapt to the characteristics of these fuels and has higher corrosion resistance and cavitation resistance to meet the needs of heavy and ultra-heavy engines for low-carbon, efficient and reliable fuel injection systems. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a low-carbon zero-carbon fuel injector assembly, which is implemented as follows: a low-carbon zero-carbon fuel injector assembly includes an injector body, a valve assembly connected to the injector body, and a nozzle pair connected thereto; the injector is provided with a control oil inlet interface, the control oil inlet interface is connected to a control oil inlet oil circuit, the control oil inlet oil circuit passes through the injector body to the valve seat of the valve assembly, the valve seat is connected to a valve plate, the valve plate is provided with a control branch oil circuit and a control oil circuit connected to the control oil inlet oil circuit; the control branch oil circuit is connected to the oil channel on the nozzle valve body in the nozzle pair, and finally reaches the upper ring cavity of the nozzle valve body; the control oil circuit is connected to the control cavity below the valve plate, and a throttling hole is provided on the control oil circuit;

[0007] There is an independent control oil return line interface on the injector body, the control chamber is connected to the oil return hole on the valve plate, the oil return hole is connected to the normally closed ball valve in the valve seat, when the normally closed ball valve is opened by the electromagnet, the oil return hole is connected to the control oil return line in the injector body;

[0008] There is an independent low-carbon / zero-carbon fuel oil inlet interface on the injector body, and the oil inlet interface is connected to the low-carbon / zero-carbon fuel through the oil inlet; the low-carbon / zero-carbon fuel passes through the injector body to the valve seat and reaches the valve plate through the oil inlet, and then passes through the main fuel oil channel hole on the valve plate to the main fuel oil channel hole on the nozzle valve body, and is finally stored in the oil tank on the nozzle valve body. When the needle valve is lifted, the main fuel will be sprayed from the spray hole into the engine combustion chamber to burn and do work.

[0009] The advantages and technical effects of the present invention are particularly outstanding and innovative compared to traditional common rail diesel injectors. In traditional designs, diesel not only serves as the main fuel, but also serves as the control oil in the control oil circuit. After entering the interior through a single interface outside the injector, it is simply divided into two oil circuits, which lead to the control chamber and the nozzle head respectively. The injector of the present invention has undergone a revolutionary improvement, with two independent inlets added, which are designed for the main fuel and the control oil, respectively, to achieve precise separation and independent management of the two inside the injector. The control oil circuit is subtly subdivided into two branches inside the injector: one leads to the control chamber, and the other cleverly extends to the nozzle valve body, and a special annular cavity is designed between the control chamber at the rear end of the valve needle and the main fuel oil tank at the front end of the valve needle. This innovative design can ensure that the pressure of the control oil circuit is always higher than that of the main fuel oil circuit when the injector is in a non-injection state, so that only a small amount of the medium in the control oil circuit leaks into the main fuel oil circuit, and burns and works together with the main fuel in the subsequent injection process, achieving efficient energy utilization. More importantly, when the injector performs the injection task, although the pressure in the control chamber will be temporarily lower than the main fuel oil circuit, thanks to the control oil circuit branch leading to the annular cavity, its pressure can still be maintained higher than the main fuel oil circuit, thereby effectively preventing the reverse leakage of the main fuel to the control oil circuit. This mechanism not only completely solves the problem of cavitation of the control mechanism valve port and moving parts due to the high saturated vapor pressure of low-carbon and zero-carbon fuels, thereby avoiding the occurrence of faults such as abnormal injection; at the same time, it also fundamentally eliminates the risk of low-carbon and zero-carbon fuels mixing into the control oil circuit and diluting the control oil, ensuring the purity and stability of the control oil circuit, and providing a solid guarantee for the long-term reliable operation of the injector. In summary, the present invention not only significantly improves the adaptability of the injector to low-carbon and zero-carbon fuels through the ingenious dual-inlet design and fine diversion of the control oil circuit, but also shows excellent technical effects in protecting the control mechanism from cavitation and preventing the dilution of the control oil, opening up a new technical path for the efficient and low-carbon operation of heavy-duty and ultra-heavy-duty engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the structure of a low-carbon and zero-carbon fuel injector;

[0011] Figure 2 It is a schematic diagram of the oil circuit of the assembly of the present invention;

[0012] Figure 3 yes Figure 2 Schematic diagram of the oil circuit of the middle nozzle pair.

[0013] In the figure: 1. Solenoid valve; 2. Spring; 3. Normally closed ball valve;

[0014] Ⅰ. Control oil inlet circuit; Ⅱ. Control oil return circuit; Ⅲ. Low carbon / zero carbon fuel inlet circuit;

[0015] A. Injector body; A-1. Control oil inlet interface; A-2. Independent control oil return interface; A-3. Independent low-carbon / zero-carbon fuel oil inlet interface; B. Valve seat; C. Valve plate; C-1. Control branch oil circuit; C-2. Control oil circuit; C-2-0. Throttle hole; C-3. Control chamber; C-4. Oil return hole; C-5. Main fuel oil channel hole; D. Nozzle; D-1. Valve body; D-2. Needle valve; D-1-1. Oil channel; D-1-2. Ring cavity; D-1-3. Main fuel oil channel hole; D-1-4. Pair; D-1-5. Oil reservoir; D-1-6. Sealing surface; D-1-7. Spray hole. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0017] See also Figure 1 and Figure 2 A low-carbon and zero-carbon fuel injector assembly comprises an injector body A, a valve assembly connected to the injector body and a nozzle pair, characterized in that: the injector is provided with a control oil inlet interface A-1, the control oil inlet interface is connected to the control oil inlet oil circuit I, the control oil inlet oil circuit passes through the injector body to the valve seat B of the valve assembly, the valve seat is connected to a valve plate C, the valve plate C is provided with a control branch oil circuit C-1 and a control oil circuit C-2 connected to the control oil inlet oil circuit; the control branch oil circuit C-1 is connected to the oil channel D-1-1 on the nozzle valve body D-1 in the nozzle pair D, and finally reaches the upper annular cavity D-1-2 of the nozzle valve body D-1; the control oil circuit C-2 is connected to the control cavity C-3 under the valve plate, and a throttle hole C-2-0 is provided on the control oil circuit C-2;

[0018] There is an independent control oil return line interface A-2 on the injector body A, the control chamber C-3 is connected to the oil return hole C-4 on the valve plate, the oil return hole C-4 is connected to the normally closed ball valve 3 in the valve seat B, when the normally closed ball valve 3 is opened by the electromagnet 1, the oil return hole C-4 is connected to the control oil return line II in the injector body A;

[0019] There is an independent low-carbon / zero-carbon fuel oil inlet interface A-3 on the injector body A, and the oil inlet interface A-3 is connected to the low-carbon / zero-carbon fuel through the oil inlet III; the low-carbon / zero-carbon fuel passes through the injector body A to the valve seat B and reaches the valve plate C through the oil inlet III, and passes through the main fuel oil channel hole C-5 on the valve plate to the main fuel oil channel hole D-1-3 on the nozzle valve body D-1, and is finally stored in the oil storage tank D-1-5 on the nozzle valve body D-1. When the needle valve D-2 is lifted, the main fuel will be sprayed from the D-1-7 spray hole into the engine combustion chamber to burn and do work.

[0020] Preferably, the pressure in the control oil inlet passage I is always greater than the pressure in the low carbon / zero carbon fuel inlet passage III, usually greater than 100 bar or even higher;

[0021] Preferably, the nozzle valve body D-1 and the needle valve D-2 form a matching section D-1-4;

[0022] Preferably, when the injector enters the stop injection state, the normally closed ball valve 3 is closed under the preload force of the spring 2, and then the oil return hole C-4 is blocked. At this time, the control oil still enters the control chamber C-3 through the control oil path C-2; when the combined force of the pressure in the control chamber C-3 and the spring preload force on the needle valve D-2 is greater than the force of the pressure in the oil tank D-1-5 on the needle valve D-2, the valve needle D-2 moves downward, the sealing surface D-1-6 is closed, and the oil injection stops;

[0023] Preferably, when the injector enters the injection start state, the normally closed ball valve 3 is opened under the action of the solenoid valve 1, and then the oil return hole C-4 is opened, and the pressure in the control chamber C-3 is reduced; when the combined force of the pressure in the control chamber C-3 and the spring preload force acting on the needle valve D-2 is less than the force of the pressure in the oil tank D-1-5 acting on the needle valve D-2, the valve needle D-2 moves upward, the sealing surface D-1-6 opens, and oil injection starts.

[0024] When the above structure is in operation, the control oil pressure connected to the control oil inlet interface (A-1) must be greater than the pressure connected to (A-3), usually greater than about 100 bar. This pressure difference is the key to ensure that the medium in the low-carbon / zero-carbon fuel inlet circuit III does not leak into the control oil inlet circuit (I) and the control oil return circuit (II). 100 bar is not a fixed value, and is usually based on the calibration result.

[0025] The advantages and technical effects of the patent of the present invention are as follows: the above technical scheme can be used to separate the control oil circuit from the main fuel oil circuit, and the control oil circuit can use a medium with a relatively low saturated vapor pressure alone to avoid cavitation of the valve port and moving parts of the control mechanism; through a unique structure, one-way leakage is achieved at the critical point between the control oil circuit and the main fuel oil circuit to prevent the control oil circuit from being diluted and contaminated, resulting in abnormal injection.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-carbon and zero-carbon fuel injector assembly, comprising an injector body (A), a valve assembly connected to the injector body, and a nozzle connection assembly (D), characterized in that: The injector is provided with a control oil inlet interface (A-1), the control oil inlet interface is connected to the control oil inlet oil circuit (I), the control oil inlet oil circuit passes through the injector body to the valve seat (B) of the valve assembly, the valve seat is connected to the valve plate (C), the valve plate (C) is provided with a control branch oil circuit (C-1) and a control oil circuit (C-2) connected to the control oil inlet oil circuit; the control branch oil circuit (C-1) is connected to the oil channel (D-1-1) on the nozzle valve body (D-1) in the nozzle pair (D), and finally reaches the upper ring cavity (D-1-2) of the nozzle valve body (D-1); the control oil circuit (C-2) is connected to the control cavity (C-3) below the valve plate, and a throttle hole (C-2-0) is provided on the control oil circuit (C-2); An independent control oil return line interface (A-2) is provided on the injector body (A), the control chamber (C-3) is connected to the oil return hole (C-4) on the valve plate, the oil return hole (C-4) is connected to the normally closed ball valve (3) in the valve seat (B), and when the normally closed ball valve (3) is opened by the electromagnet (1), the oil return hole (C-4) is connected to the control oil return line (II) in the injector body (A); An independent low-carbon / zero-carbon fuel oil inlet interface (A-3) is provided on the injector body (A), and the oil inlet interface (A-3) is connected to the low-carbon / zero-carbon fuel through the oil inlet (III); the low-carbon / zero-carbon fuel passes through the injector body (A) to the valve seat (B) and reaches the valve plate (C) through the oil inlet (III), and then passes through the main fuel oil channel hole (C-5) on the valve plate to the main fuel oil channel hole (D-1-3) on the nozzle valve body (D-1), and is finally stored in the oil storage tank (D-1-5) on the nozzle valve body (D-1). When the needle valve (D-2) is lifted, the main fuel will be sprayed from the spray hole (D-1-7) into the engine combustion chamber to burn and do work.

Images