Hydrodynamically-driven hydrogen injection system and control method

Abstract

The hydraulic-driven hydrogen injection system comprises a hydrogen nozzle, a hydraulic supply assembly and a hydrogen supply assembly, the hydrogen nozzle comprises an injection valve, the injection valve comprises a valve body, a valve rod and an elastic reset piece, a piston head and a plugging head are arranged at the two ends of the valve rod correspondingly, and the valve body is provided with a hydrogen cavity, a piston cavity and a sliding groove channel; the sliding channel is connected between the hydrogen cavity and the piston cavity, the piston head is arranged in the piston cavity in a sealed and sliding mode to form a hydraulic control cavity, the hydrogen cavity is provided with an air inlet and an air outlet, the valve rod is in sealed and sliding fit with the sliding channel, a lubricating and sealing oil hole is formed in the side wall of the sliding channel, and the elastic reset piece acts between the valve rod and the valve body in the axial direction. The air outlet is plugged by the plugging head; the hydraulic supply assembly is communicated with the hydraulic control cavity and the lubricating sealing oil hole; the hydrogen supply assembly is connected with the gas inlet. The nozzle has good hydrogen sealing performance and low abrasion performance, bounce in the opening and closing process of the nozzle is reduced, and the service life of the nozzle is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen injection, in particular to a hydraulically driven hydrogen injection system and a control method. Background Art

[0002] In direct injection hydrogen engines, pressures greater than 60 bar are generally considered high pressure. With high-pressure hydrogen direct injection, injection can be performed in the late stage of the engine compression phase, and the injection duration is short, which is beneficial to improving the combustion efficiency of the engine. However, due to the low volume energy density of hydrogen, a larger volume flow rate is required. Compared with conventional injectors, a larger flow cross-sectional area and a larger stroke are required, resulting in a significant increase in the required driving force, especially with high-pressure injection. Therefore, it becomes very difficult to achieve high-pressure direct injection using an electromagnetic direct drive solution. Hydrogen molecules are small and difficult to seal, especially with high-pressure injection. Since hydrogen does not have a lubricating effect, the risk of wear on the moving parts is greatly increased; in addition, the damping of the hydrogen compression process is low, the impact stress of the nozzle during the switching process is large, and the bounce is significantly increased, resulting in flow fluctuations and reduced life. Summary of the invention The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a hydraulically driven hydrogen injection system and control method, which has good hydrogen sealing and low wear resistance, can reduce the bounce during the nozzle switching process, reduce the nozzle flow fluctuation, and increase the life of the nozzle.

[0003] A hydraulically driven hydrogen injection system according to a first aspect of an embodiment of the present invention comprises: A hydrogen nozzle comprises an injection valve, wherein the injection valve comprises a valve body, a valve stem and an elastic reset member, wherein the valve stem is slidably arranged in the valve body, and a piston head and a plugging head are respectively arranged at two ends of the valve stem, the valve body is provided with a hydrogen chamber, a piston chamber and a sliding groove, the sliding groove is connected between the hydrogen chamber and the piston chamber, the piston head is sealingly and slidably arranged in the piston chamber to form a hydraulic control chamber, the hydrogen chamber is provided with an air inlet and an air outlet, the valve stem is sealingly and slidably matched with the sliding groove, the plugging head is configured to plug and open the air outlet, the side wall of the sliding groove is provided with a lubricating sealing oil hole, and the elastic reset member acts axially between the valve stem and the valve body so that the plugging head plugs the air outlet; A hydraulic supply assembly, connected to the hydraulic control chamber and the lubricating seal oil hole; A hydrogen supply assembly is connected to the air inlet, and the hydrogen supply assembly includes a hydraulic pressure regulating valve, which is connected to the hydraulic supply assembly, and the outlet pressure of the hydraulic pressure regulating valve is controlled by the hydraulic pressure of the hydraulic supply assembly.

[0004] The hydrogen injection system according to the embodiment of the present invention has at least the following beneficial effects: When in use, high-pressure hydraulic oil is provided to the hydraulic control chamber, the lubricating sealing oil hole and the hydraulic pressure regulating valve through the hydraulic supply component. The outlet pressure of the hydraulic pressure regulating valve is controlled by the hydraulic pressure of the hydraulic supply component to adjust the hydrogen pressure of the hydrogen supply component. The outlet hydrogen pressure of the hydraulic pressure regulating valve 320 is controlled by the pressure of the hydraulic oil to achieve arbitrary adjustment and closed-loop control of the hydrogen injection pressure, so as to meet the requirements of the hydrogen engine for different hydrogen pressures in various combustion modes. The hydraulic oil in the hydraulic control chamber pushes the piston head to move, overcomes the force of the elastic reset part, drives the valve stem to slide, and makes the sealing head open the air outlet. The high-pressure hydrogen provided by the hydrogen supply component to the hydrogen chamber is sprayed out through the air outlet. At the same time, the hydraulic oil enters the sliding groove through the lubricating sealing oil hole to press the valve stem and Sealing and lubrication are performed between the sliding grooves to solve the wear problem caused by dry friction. When the hydraulic oil in the hydraulic control chamber is discharged, the valve stem is pushed to reset by the elastic reset member, so that the plugging head blocks the air outlet, and the hydraulic oil entering from the lubricating sealing oil hole will slightly seep into the plugging head to improve the sealing between the plugging head and the air outlet. In addition, during the closing process, the pressure of the hydraulic oil entering from the lubricating sealing oil hole is kept higher than the hydrogen pressure, which can prevent the high-pressure hydrogen from flowing back into the hydraulic control chamber when the pressure in the hydraulic control chamber is reduced; when switching under the action of oil pressure, the damping effect of the liquid can slow down the seating of the valve stem, reduce the impact and bounce of the valve stem during the switching process, which is beneficial to reduce flow fluctuations, improve consistency under small flow rates, and increase the service life of the nozzle.

[0005] According to some embodiments of the present invention, the valve stem is provided with a sliding section that is sealingly and slidingly matched with the sliding channel, the sliding section and the sealing head are spaced apart, the outer diameter of the sliding section is larger than the outer diameter of the valve stem, the inner diameter of the air outlet is larger than the outer diameter of the valve stem, and the sealing head is provided with a sealing surface that is sealingly abutted against the outer end of the air outlet.

[0006] According to some embodiments of the present invention, the sealing surface is an annular outer conical surface structure, and the inner peripheral wall of the air outlet is an annular inner conical surface structure matching the annular outer conical surface structure.

[0007] According to some embodiments of the present invention, the elastic return member is a return spring sleeved on the outer periphery of the valve stem, a limiting step is provided in the valve body, and two ends of the return spring act on the limiting step and the piston head respectively.

[0008] According to some embodiments of the present invention, the hydraulic supply assembly includes an oil tank, a high-pressure oil pump and an oil rail connected in sequence; The hydrogen nozzle further includes an electromagnetic switching valve, which is a two-position three-way electromagnetic valve, and is provided with an oil inlet, an oil inlet and an outlet, and a first oil return port, wherein the oil inlet and the outlet are in communication with the hydraulic control chamber, the oil inlet is connected to the oil rail, and the first oil return port is connected to the oil tank; The oil rail is communicated with the lubrication sealing oil hole.

[0009] According to some embodiments of the present invention, the valve body is provided with a second oil return port located between the sliding channel and the piston chamber, and the second oil return port is connected to the oil tank.

[0010] According to some embodiments of the present invention, the hydrogen supply assembly includes a hydrogen bottle and a hydrogen rail, the hydraulic pressure regulating valve is arranged between the hydrogen bottle and the hydrogen rail, the hydraulic pressure regulating valve is connected to the oil rail, the outlet pressure of the hydraulic pressure regulating valve is controlled by the hydraulic pressure of the oil rail, and the hydrogen rail is connected to the air inlet.

[0011] According to some embodiments of the present invention, the hydrogen supply assembly further includes a shut-off valve, a gas cylinder pressure sensor and a hydrogen rail pressure sensor, the shut-off valve and the gas cylinder pressure sensor being arranged between the hydrogen cylinder and the hydraulic pressure regulating valve, and the hydrogen rail pressure sensor being arranged on the hydrogen rail.

[0012] According to some embodiments of the present invention, the hydraulic supply assembly further includes a low-pressure oil pump, a filter and a rail pressure sensor, the low-pressure oil pump and the filter are arranged between the oil tank and the high-pressure oil pump, and the rail pressure sensor is arranged on the oil rail.

[0013] A control method according to a second aspect of an embodiment of the present invention is applicable to the hydrogen injection system, and the control method includes: Passing high-pressure hydraulic oil into the hydraulic pressure regulating valve to adjust the hydrogen pressure of the hydrogen supply assembly; High-pressure hydraulic oil is introduced into the hydraulic control chamber, and the valve stem is driven to slide through the piston head, so that the plugging head opens the gas outlet and hydrogen is ejected from the gas inlet; Passing high-pressure hydraulic oil into the lubricating sealing oil hole to lubricate and seal between the sliding channel and the valve stem; The hydraulic oil in the hydraulic control chamber is drained, and the elastic reset member pushes the valve stem to reset, so that the plugging head blocks the air outlet.

[0014] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 It is a structural schematic diagram of the hydrogen injection system of the present invention; Figure 2 yes Figure 1 A partial enlarged view of part A; Figure 3 is a flow chart of the control method of the present invention; Figure Number: Hydrogen nozzle 100; injection valve 110; valve body 111; limiting step 1111; valve stem 112; sliding section 1121; elastic reset member 113; piston head 114; plugging head 115; sealing surface 1151; piston cavity 116; sliding channel 117; lubricating sealing oil hole 1171; hydrogen cavity 118; air inlet 1181; air outlet 1182; hydraulic control cavity 119; solenoid switching valve 120; oil inlet 121; oil inlet and outlet 122; first oil return port 123; second oil return port 130; second oil return channel 131; Hydraulic supply assembly 200; oil tank 210; first oil return passage 211; high-pressure oil pump 220; oil rail 230; first oil inlet passage 231; second oil inlet passage 232; low-pressure oil pump 240; filter 250; rail pressure sensor 260; Hydrogen supply assembly 300 ; hydrogen cylinder 310 ; hydraulic pressure regulating valve 320 ; third oil inlet passage 321 ; hydrogen rail 330 ; stop valve 340 ; cylinder pressure sensor 350 ; hydrogen rail pressure sensor 360 . DETAILED DESCRIPTION

[0016] 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.

[0017] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the 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 should not be understood as a limitation on the present invention.

[0018] In the description of the present invention, "a plurality" means more than two. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0019] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0020] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described below are only some embodiments of the present invention, not all embodiments.

[0021] In direct injection hydrogen engines, pressures greater than 60 bar are generally considered high pressure. With high-pressure hydrogen direct injection, injection can be performed in the late stage of the engine compression phase, and the injection duration is short, which is beneficial to improving the combustion efficiency of the engine. However, due to the low volume energy density of hydrogen, a larger volume flow rate is required. Compared with conventional injectors, a larger flow cross-sectional area and a larger stroke are required, resulting in a significant increase in the required driving force, especially with high-pressure injection. Therefore, it becomes very difficult to achieve high-pressure direct injection using an electromagnetic direct drive solution. Hydrogen molecules are small and difficult to seal, especially with high-pressure injection. Since hydrogen does not have a lubricating effect, the risk of wear on the moving parts is greatly increased. In addition, the damping of the hydrogen compression process is low, the impact stress of the nozzle during the switching process is large, and the bounce is significantly increased, resulting in flow fluctuations and reduced life.

[0022] Therefore, an embodiment of the present invention proposes a hydraulically driven hydrogen injection system, which can realize arbitrary adjustment and control of the hydrogen injection pressure (10-150bar) to meet the requirements of different hydrogen pressures of various combustion modes of hydrogen engines; it has good hydrogen sealing and particularly low wear; and due to the effect of hydraulic damping, it can reduce the bounce during the nozzle switching process, reduce the nozzle flow fluctuation, and increase the life of the nozzle.

[0023] like Figure 1 and 2 As shown, the hydraulically driven hydrogen injection system according to the embodiment of the present invention includes: a hydrogen nozzle 100 , a hydraulic supply assembly 200 and a hydrogen supply assembly 300 .

[0024] Among them, Figure 1 As shown, the hydrogen nozzle 100 includes an injection valve 110, and the injection valve 110 includes a valve body 111, a valve stem 112 and an elastic return member 113. In this embodiment, the valve stem 112 is extended up and down as an example. In some other embodiments, the valve stem 112 can extend in other directions.

[0025] The valve stem 112 of the embodiment of the present invention is slidable up and down in the valve body 111, a piston head 114 is provided at the upper end of the valve stem 112, and a plugging head 115 is provided at the lower end of the valve stem 112. A piston cavity 116, a sliding groove 117 and a hydrogen cavity 118 are provided in the valve body 111 from top to bottom, and the sliding groove 117 is connected between the hydrogen cavity 118 and the piston cavity 116, so that the piston cavity 116, the sliding groove 117 and the hydrogen cavity 118 are interconnected. It can be understood that the valve stem 112 is slidable up and down in the piston cavity 116, the sliding groove 117 and the hydrogen cavity 118.

[0026] The hydrogen chamber 118 of the embodiment of the present invention is provided with an air inlet 1181 and an air outlet 1182 , wherein the air outlet 1182 is located at the bottom of the hydrogen chamber 118 , and the air inlet 1181 is used for hydrogen to flow in, and the air inlet 1181 is connected to the hydrogen supply assembly 300 .

[0027] The piston head 114 of this embodiment is sealed and slidably arranged in the piston cavity 116, and the top of the piston head 114 and the piston cavity 116 form a hydraulic control cavity 119. The hydraulic control cavity 119 is connected to the hydraulic supply component 200. The hydraulic supply component 200 of this embodiment provides high-pressure hydraulic oil and drain oil to the hydraulic control cavity 119. In some embodiments, the hydraulic control cavity 119 can be provided with a separate pressure relief oil channel.

[0028] The valve stem 112 of this embodiment is sealed and slidably matched with the sliding groove 117, and a lubricating sealing oil hole 1171 is provided on the side wall of the sliding groove 117. The lubricating sealing oil hole 1171 is also connected to the hydraulic supply component 200. The hydraulic supply component 200 supplies high-pressure hydraulic oil to the lubricating sealing oil hole 1171, so that an oil seal with lubrication and sealing functions is formed between the valve stem 112 and the sliding groove 117.

[0029] The plugging head 115 of the embodiment of the present invention is configured to plug and open the gas outlet 1182 . When the valve stem 112 moves up and down, the plugging head 115 can be driven to move up and down to achieve the plugging and opening of the gas outlet 1182 .

[0030] The elastic return member 113 of the embodiment of the present invention acts axially between the valve stem 112 and the valve body 111 to enable the sealing head 115 to block the air outlet 1182. It can be understood that, in a natural state, the elastic return member 113 drives the valve stem 112 to return to the position where the sealing head 115 blocks the air outlet 1182.

[0031] When in use, high-pressure hydraulic oil is provided to the hydraulic control chamber 119 and the lubricating sealing oil hole 1171 through the hydraulic supply component 200. The hydraulic oil in the hydraulic control chamber 119 pushes the piston head 114 to move, overcomes the force of the elastic reset member 113, and drives the valve stem 112 to slide, so that the plugging head 115 opens the air outlet 1182. The high-pressure hydrogen provided by the hydrogen supply component 300 to the hydrogen chamber 118 is sprayed out through the air outlet 1182. At the same time, the hydraulic oil enters the sliding groove 117 through the lubricating sealing oil hole 1171, and seals and lubricates the valve stem 112 and the sliding groove 117, thereby solving the wear problem caused by dry friction. When the hydraulic oil in the hydraulic control chamber 119 is discharged, the elastic reset member 113 is pushed The valve stem 112 is reset, so that the plugging head 115 blocks the air outlet 1182, and the hydraulic oil entering from the lubricating sealing oil hole 1171 will slightly seep into the plugging head 115 to improve the sealing between the plugging head 115 and the air outlet 1182. In addition, during the closing process, the pressure of the hydraulic oil entering from the lubricating sealing oil hole 1171 is kept higher than the hydrogen pressure, which can prevent the high-pressure hydrogen from flowing back into the hydraulic control chamber 119 when the pressure of the hydraulic control chamber 119 is reduced; when switching under the action of oil pressure, the damping effect of the liquid can slow down the seating of the valve stem 112, reduce the impact and bounce of the valve stem 112 during the switching process, which is beneficial to reduce flow fluctuations, improve consistency under small flow rates, and increase the service life of the nozzle.

[0032] Further, the valve stem 112 of the embodiment of the present invention is provided with a sliding section 1121, the sliding section 1121 is sealingly slidably matched with the sliding groove 117, the sliding section 1121 and the plugging head 115 are arranged at intervals, the outer diameter of the sliding section 1121 is larger than the outer diameter of the valve stem 112, the inner diameter of the air outlet 1182 is larger than the outer diameter of the valve stem 112, and the plugging head 115 is provided with a sealing surface 1151, and the sealing surface 1151 is located at the top of the plugging head 115, and the plugging head 115 is sealed and abutted with the outer end of the air outlet 1182 through the sealing surface 1151 to achieve the plugging of the air outlet 1182, such as Figure 1 As shown, the outer diameter of the part of the valve stem 112 passing through the hydrogen chamber 118 is smaller than the sliding section 1121 and the plugging head 115, and the pressure of the high-pressure hydrogen in the hydrogen chamber 118 acts axially on the top of the plugging head 115 and the bottom of the sliding section 1121 respectively. It can be understood that the injection valve 110 of the embodiment of the present invention is a balanced outward-opening injection valve 110, which makes the upward air pressure and the downward air pressure acting on the valve stem 112 equal. To close the valve stem 112, it is only necessary to ensure the reset spring force required for the sealing of the plugging head 115, and when opening the air outlet 1182, it is only necessary to overcome the elastic force of the elastic reset member 113.

[0033] In order to ensure sealing, a larger restoring elastic force is required. Since hydraulic drive is adopted, the restoring elastic force can be appropriately increased by increasing the hydraulic pressure to improve the sealing effect of the sealing surface 1151.

[0034] In order to further improve the sealing performance, the sealing surface 1151 is configured as an annular outer cone structure, and the inner peripheral wall of the air outlet 1182 is configured as an annular inner cone structure that matches the annular outer cone structure.

[0035] The elastic return member 113 of the embodiment of the present invention adopts a return spring, which is sleeved on the outer periphery of the valve stem 112. A limiting step 1111 is provided in the valve body 111. The lower end and upper end of the return spring act on the limiting step 1111 and the bottom of the piston head 114 respectively.

[0036] like Figure 1 As shown, the hydraulic supply assembly 200 of this embodiment includes an oil tank 210 , a high-pressure oil pump 220 and an oil rail 230 which are connected in sequence, and the pressure of the hydraulic oil is adjusted by controlling the oil supply of the high-pressure oil pump 220 .

[0037] Furthermore, the hydraulic supply assembly 200 also includes a low-pressure oil pump 240, a filter 250 and a rail pressure sensor 260. The low-pressure oil pump 240 and the filter 250 are arranged between the oil tank 210 and the high-pressure oil pump 220. The rail pressure sensor 260 is installed on the oil rail 230. The pressure in the oil rail 230 is monitored by the rail pressure sensor 260, and the hydraulic oil is filtered by the filter 250. Gradual pressurization is achieved through the mutual cooperation of the low-pressure oil pump 240 and the high-pressure oil pump 220.

[0038] The hydrogen supply assembly 300 includes a hydrogen bottle 310, a hydraulic pressure regulating valve 320 and a hydrogen rail 330 connected in sequence. The hydraulic pressure regulating valve 320 is connected to the oil rail 230 through a third oil inlet channel 321. The outlet pressure of the hydraulic pressure regulating valve 320 is controlled by the hydraulic pressure of the oil rail 230. The hydrogen rail 330 is connected to the air inlet 1181 through a hydrogen inlet channel 331.

[0039] When in use, the ECU is connected to the rail pressure sensor 260 and the high-pressure oil pump 220. The hydraulic supply assembly 200 provides the hydraulic oil required for driving the hydrogen nozzle 100 and operating the hydraulic pressure regulating valve 320. The pressure of the hydraulic oil is adjusted by the ECU controlling the oil supply of the high-pressure oil pump 220.

[0040] Furthermore, the hydrogen supply assembly 300 also includes a shut-off valve 340, a gas cylinder pressure sensor 350 and a hydrogen rail pressure sensor 360. The shut-off valve 340 and the gas cylinder pressure sensor 350 are arranged between the hydrogen cylinder 310 and the hydraulic pressure regulating valve 320, the hydrogen rail pressure sensor 360 is arranged on the hydrogen rail 330, and the ECU is connected to the gas cylinder pressure sensor 350 and the hydrogen rail pressure sensor 360.

[0041] After the high-pressure hydrogen in the hydrogen cylinder 310 is depressurized by the hydraulic pressure regulating valve 320, it enters the hydrogen rail 330 and then enters the hydrogen chamber 118 through the hydrogen inlet 331. The outlet pressure of the hydraulic pressure regulating valve 320 is controlled by the pressure of the third oil inlet 321. The greater the pressure of the third oil inlet 321, the greater the outlet pressure of the hydraulic pressure regulating valve 320. The ECU monitors the pressure of the hydrogen rail pressure sensor 360 and adjusts the pressure in the oil rail 230 by controlling the oil supply of the high-pressure oil pump 220, thereby adjusting the outlet pressure of the hydraulic pressure regulating valve 320, thereby realizing arbitrary adjustment and closed-loop control of the hydrogen injection pressure, meeting the requirements of different hydrogen pressures under various combustion modes of the hydrogen engine, improving the utilization rate of hydrogen in the hydrogen cylinder 310, and solving the problem of short driving range of the whole vehicle.

[0042] The hydrogen nozzle 100 of this embodiment also includes an electromagnetic switching valve 120, which is a two-position three-way electromagnetic valve. The electromagnetic switching valve 120 is connected to the ECU. The electromagnetic switching valve 120 is provided with an oil inlet 121, an oil inlet and outlet 122 and a first oil return port 123. The oil inlet and outlet 122 are connected to the hydraulic control chamber 119, the oil inlet 121 is connected to the oil rail 230 through the first oil inlet passage 231, the first oil return port 123 is connected to the oil tank 210 through the first oil return passage 211, and the oil rail 230 is connected to the lubrication sealing oil hole 1171 through the second oil inlet passage 232.

[0043] When the electromagnetic switching valve 120 is not energized, the oil inlet and outlet 122 and the first oil return port 123 are interconnected, and the pressure of the hydraulic control chamber 119 is low pressure. At this time, the valve stem 112 is in a closed state under the action of the return spring. The electromagnetic switching valve 120 is controlled by the engine ECU. When the ECU sends a current signal, the electromagnetic switching valve 120 opens, the oil inlet 121 and the oil inlet and outlet 122 are interconnected, and the pressure of the hydraulic control chamber 119 is high pressure. The high-pressure oil pressure acting on the valve stem 112 overcomes the force of the return spring, so that the valve stem 112 opens to spray hydrogen. When the ECU ends the current signal, the oil inlet and outlet 122 and the first oil return port 123 are interconnected, and the valve stem 112 is closed again under the action of the return spring, and the hydrogen injection ends. Therefore, the opening and closing of the hydraulically driven injection valve 110 can be realized.

[0044] Since the injection valve 110 is a balanced outward-opening injection valve 110, the opening of the electromagnetic switching valve 120 only needs to overcome the spring force, which has nothing to do with the hydrogen pressure. In order to overcome the spring force, only a higher hydraulic force is required, which reduces the demand for electromagnetic force and makes the hydrogen nozzle 100 applicable to a wider pressure range. In order to ensure sealing, a larger spring force is required. Since hydraulic drive is adopted, the spring force can be appropriately increased by increasing the hydraulic pressure to improve the sealing effect of the sealing seat surface.

[0045] In addition, the valve body 111 of the embodiment of the present invention is provided with a second oil return port 130 located between the sliding groove 117 and the piston chamber 116. The second oil return port 130 is connected to the oil tank 210 through the second oil return channel 131. In actual operation, the oil seeping between the sliding groove 117 and the valve stem 112, and between the piston chamber 116 and the piston head 114 flows back to the oil tank 210 through the second oil return port 130, ensuring that there is no blockage in the valve body 111.

[0046] The injection valve 110 of the embodiment of the present invention adopts a special surface coating technology, which can prevent hydrogen embrittlement of the material, while improving the surface hardness of the material, improving the impact resistance of the valve stem 112 and the valve body 111, and effectively increasing the service life of the nozzle.

[0047] like Figure 3 As shown, the embodiment of the present invention also provides a control method for the above hydrogen injection system, and the control method includes the following steps: Step S100: introducing high-pressure hydraulic oil into the hydraulic pressure regulating valve 320 to adjust the hydrogen pressure of the hydrogen supply assembly 300; Step S200: High-pressure hydraulic oil is introduced into the hydraulic control chamber 119, and the valve stem 112 is driven to slide through the piston head 114, so that the plugging head 115 opens the gas outlet 1182, and hydrogen is ejected from the gas inlet 1181; Step S300: high-pressure hydraulic oil is introduced into the lubricating sealing oil hole 1171 to lubricate and seal between the sliding groove 117 and the valve stem 112; Step S400 : the hydraulic oil in the hydraulic control chamber 119 is discharged, and the elastic reset member 113 pushes the valve stem 112 to reset, so that the plugging head 115 blocks the air outlet 1182 .

[0048] In step S100 and step S200, the electromagnetic switching valve 120 is controlled by the ECU to connect the hydraulic control chamber 119 with the oil rail 230. At the same time, the ECU controls the high-pressure oil pump 220 to control the oil pressure of the oil rail 230 to control the outlet hydrogen pressure of the hydraulic pressure regulating valve 320 to control the injection pressure of the hydrogen.

[0049] In step S400 , the electromagnetic switching valve 120 is controlled by the ECU to connect the hydraulic control chamber 119 with the oil tank 210 .

[0050] In step S300 , the ECU controls the high-pressure oil pump 220 to control the oil pressure of the oil rail 230 to control the oil pressure flowing through the lubricating seal oil hole 1171 to control the sealing lubricating pressure of the hydraulic oil.

[0051] The present invention can realize the opening and closing of the high-pressure oil-driven injection valve 110 through the designed hydraulically driven hydrogen injection system, thereby realizing the high-pressure direct injection of hydrogen. The lubrication effect of the hydraulic oil is used to reduce the wear problem of the valve stem 112 and the valve body 111, and it is also beneficial to improve the sealing of the valve stem 112 and the valve body 111. The damping effect of the hydraulic oil is used to slow down the seating of the valve stem 112, solve the problem of large impact force of the valve seat and bouncing when seating, which is beneficial to reduce the fluctuation of the flow rate, improve the consistency under small flow rate, and increase the service life of the nozzle. At the same time, the valve stem 112 and the valve body 111 adopt a special surface coating technology, which can prevent hydrogen embrittlement and increase the surface hardness of the material, thereby increasing the service life of the injection valve 110. The injection valve 110 adopts a balanced valve structure, and the gas pressures are balanced with each other. Closing the valve stem 112 only requires the spring force required to ensure the sealing of the valve seat, so that the injection valve 110 has a wider pressure range. Due to the use of hydraulic drive, the spring force can be appropriately increased by increasing the hydraulic pressure to improve the sealing effect of the nozzle. The ECU controls the oil supply of the high-pressure oil pump 220 to adjust the pressure of the hydraulic oil. The pressure of the hydraulic oil can control the size of the outlet hydrogen pressure of the hydraulic pressure regulating valve 320, and can realize arbitrary adjustment and closed-loop control of the hydrogen injection pressure, meet the needs of the hydrogen engine for different hydrogen pressures in various combustion modes, improve the utilization rate of hydrogen in the hydrogen bottle 310, and solve the problem of short driving range of the whole vehicle.

[0052] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0053] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A hydraulically driven hydrogen injection system, characterized in that: include: A hydrogen nozzle comprises an injection valve, wherein the injection valve comprises a valve body, a valve stem and an elastic reset member, wherein the valve stem is slidably arranged in the valve body, and a piston head and a plugging head are respectively arranged at two ends of the valve stem, the valve body is provided with a hydrogen chamber, a piston chamber and a sliding groove, the sliding groove is connected between the hydrogen chamber and the piston chamber, the piston head is sealingly and slidably arranged in the piston chamber to form a hydraulic control chamber, the hydrogen chamber is provided with an air inlet and an air outlet, the valve stem is sealingly and slidably matched with the sliding groove, the plugging head is configured to plug and open the air outlet, the side wall of the sliding groove is provided with a lubricating sealing oil hole, and the elastic reset member acts axially between the valve stem and the valve body so that the plugging head plugs the air outlet; A hydraulic supply assembly, connected to the hydraulic control chamber and the lubricating seal oil hole; A hydrogen supply assembly is connected to the air inlet, and the hydrogen supply assembly includes a hydraulic pressure regulating valve, which is connected to the hydraulic supply assembly, and the outlet pressure of the hydraulic pressure regulating valve is controlled by the hydraulic pressure of the hydraulic supply assembly.

2. The hydrogen injection system according to claim 1, characterized in that: The valve stem is provided with a sliding section that is sealingly slidably matched with the sliding groove, the sliding section and the sealing head are arranged at an interval, the outer diameter of the sliding section is larger than the outer diameter of the valve stem, the inner diameter of the air outlet is larger than the outer diameter of the valve stem, and the sealing head is provided with a sealing surface that is sealingly abutted against the outer end of the air outlet.

3. The hydrogen injection system according to claim 2, characterized in that: The sealing surface is an annular outer cone structure, and the inner peripheral wall of the air outlet is an annular inner cone structure matching the annular outer cone structure.

4. The hydrogen injection system according to claim 1, characterized in that: The elastic reset member is a reset spring sleeved on the outer periphery of the valve stem, a limiting step is arranged in the valve body, and two ends of the reset spring act on the limiting step and the piston head respectively.

5. The hydrogen injection system according to claim 1, characterized in that: The hydraulic supply assembly includes an oil tank, a high-pressure oil pump and an oil rail connected in sequence; The hydrogen nozzle further includes an electromagnetic switching valve, which is a two-position three-way electromagnetic valve, and is provided with an oil inlet, an oil inlet and an outlet, and a first oil return port, wherein the oil inlet and the outlet are in communication with the hydraulic control chamber, the oil inlet is connected to the oil rail, and the first oil return port is connected to the oil tank; The oil rail is communicated with the lubrication sealing oil hole.

6. The hydrogen injection system according to claim 5, characterized in that: The valve body is provided with a second oil return port located between the sliding channel and the piston chamber, and the second oil return port is connected to the oil tank.

7. The hydrogen injection system according to claim 5, characterized in that: The hydrogen supply assembly includes a hydrogen bottle and a hydrogen rail, the hydraulic pressure regulating valve is arranged between the hydrogen bottle and the hydrogen rail, the hydraulic pressure regulating valve is connected to the oil rail, the outlet pressure of the hydraulic pressure regulating valve is controlled by the hydraulic pressure of the oil rail, and the hydrogen rail is connected to the air inlet.

8. The hydrogen injection system according to claim 7, characterized in that: The hydrogen supply assembly further includes a shutoff valve, a gas cylinder pressure sensor and a hydrogen rail pressure sensor. The shutoff valve and the gas cylinder pressure sensor are arranged between the hydrogen cylinder and the hydraulic pressure regulating valve, and the hydrogen rail pressure sensor is arranged on the hydrogen rail.

9. The hydrogen injection system according to claim 5, characterized in that: The hydraulic supply assembly further includes a low-pressure oil pump, a filter and a rail pressure sensor. The low-pressure oil pump and the filter are arranged between the oil tank and the high-pressure oil pump, and the rail pressure sensor is arranged on the oil rail.

10. A control method, characterized in that: Applicable to the hydrogen injection system according to any one of claims 1 to 9, the control method comprises: Passing high-pressure hydraulic oil into the hydraulic pressure regulating valve to adjust the hydrogen pressure of the hydrogen supply assembly; High-pressure hydraulic oil is introduced into the hydraulic control chamber, and the valve stem is driven to slide through the piston head, so that the plugging head opens the gas outlet and hydrogen is ejected from the gas inlet; Passing high-pressure hydraulic oil into the lubricating sealing oil hole to lubricate and seal between the sliding channel and the valve stem; The hydraulic oil in the hydraulic control chamber is drained, and the elastic reset member pushes the valve stem to reset, so that the plugging head blocks the air outlet.

Images