A high-pressure hydrogen pressure reducing valve group with high pressure regulation accuracy and method thereof

Abstract

The application discloses a high-pressure hydrogen pressure reducing valve group with high pressure regulating precision and a method thereof, and belongs to the field of pressure reducing valve devices. The high-pressure hydrogen pressure reducing valve group mainly comprises an overpressure conduction valve which is conducted when the inlet pressure is too large, a pair of primary pressure reducing valves and secondary pressure reducing valves which are coaxially arranged in an upper and lower manner. In a high-inlet-pressure interval, the upper high-pressure interval pressure reducing valve keeps being conducted to reduce pressure, and the lower low-pressure interval pressure reducing valve is automatically closed under the action of high pressure; in a low-inlet-pressure interval, the lower low-pressure interval pressure reducing valve keeps being conducted to reduce pressure, and the upper high-pressure interval pressure reducing valve is automatically closed under the action of a spring. The gas after primary pressure reduction enters the secondary pressure reducing valve, and secondary pressure reduction is realized, so that the outlet pressure is stable. The high-pressure interval pressure reducing valve and the low-pressure interval pressure reducing valve are matched to realize sectional pressure reduction, the inlet pressure interval is expanded, the hydrogen pressure after pressure reduction of the pressure reducing valve group is stable, and the process that the front-end pressure of the hydrogen storage bottle releasing gas is reduced is adapted.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pressure reducing valve devices, in particular to an integrated two-stage pressure reducing valve set for use in a hydrogen supply system of a fuel cell. BACKGROUND

[0002] With the development of hydrogen energy industry, the field of hydrogen fuel cell vehicles has gradually become a major direction of technical development and market development. Higher pressure specifications of hydrogen storage cylinders mean higher energy density, and in order to improve the mileage of fuel cell vehicles, the storage pressure of high-pressure hydrogen gas has been increased from 35 MPa to 70 MPa.

[0003] The hydrogen supply system of a hydrogen fuel cell vehicle connects a high-pressure hydrogen storage cylinder and a fuel cell stack system to realize the functions of reducing the pressure of hydrogen gas and maintaining the stability of the supply pressure. Both excessive and insufficient hydrogen gas pressure after the hydrogen supply system will greatly affect the working efficiency and service life of the fuel cell. The core component of the hydrogen supply system is the pressure reducing valve set, which reduces the high-pressure hydrogen gas (2-70 MPa) in the hydrogen storage cylinder to a suitable pressure range (such as about 0.16 MPa) for the fuel cell. Therefore, the performance of a hydrogen fuel cell vehicle depends largely on the performance of the pressure reducing valve set in the hydrogen supply system.

[0004] Currently, the import pressure range of a vehicle-mounted 70 MPa specification high-pressure hydrogen storage cylinder is large. An excessively large import pressure range will cause the pressure reducing performance to decrease or even fail. A single pressure reducing valve cannot achieve stable pressure reduction in the entire range. Therefore, a pressure reducing valve set often uses two-stage pressure reducing valves to achieve stable pressure reduction. A pressure reducing valve set with two-stage pressure reducing valves usually uses a primary pressure reducing valve to bear the main pressure reducing capacity. The large import pressure range of the primary pressure reducing valve will cause a large pressure range after the primary pressure reducing valve, which will eventually affect the control accuracy of the hydrogen gas pressure after the secondary pressure reducing valve and affect the working efficiency of the hydrogen fuel cell.

[0005] In view of the above, it is necessary to further design the structure of the pressure reducing valve set to improve the control accuracy of the hydrogen gas pressure after the secondary pressure reducing valve and thus improve the working efficiency and service life of the hydrogen fuel cell. SUMMARY

[0006] The present application aims to overcome the defects in the prior art and provide a high-pressure hydrogen gas pressure reducing valve set with high pressure regulation accuracy and a method thereof. The present application improves the pressure regulation accuracy after the pressure reducing valve set through primary pressure reduction and secondary pressure reduction in different ranges, and can maintain the stability of the outlet flow and pressure. In addition, it should have an overpressure protection effect.

[0007] The specific technical solutions adopted by the present application are as follows:

[0008] In a first aspect, the application provides a high-pressure hydrogen pressure reducing valve group with high pressure regulating precision, comprising an overpressure guide valve, a high-pressure interval pressure reducing valve, a low-pressure interval pressure reducing valve and a second-stage pressure reducing valve installed on a valve body; one side of the valve body is provided with an inlet, and the other side is provided with an outlet; the bottom gas inlet of the overpressure guide valve is communicated with the inlet, and two gas outlets are respectively connected with two independent cavities of the high-pressure interval pressure reducing valve, for controlling the opening and closing of the bottom gas inlet of the high-pressure interval pressure reducing valve according to the gas pressure; the high-pressure interval pressure reducing valve is used for opening to perform first-stage pressure reduction when the pressure is high, and the bottom gas inlet thereof is communicated with the inlet, and the gas outlet is connected with the outlet through the second-stage pressure reducing valve; the low-pressure interval pressure reducing valve is used for opening to perform first-stage pressure reduction when the pressure is low, and two independent cavities thereof are respectively connected with the inlet, can control the opening and closing according to the gas pressure, and the gas outlet is connected with the outlet through the second-stage pressure reducing valve.

[0009] Preferably, the overpressure guide valve comprises an overpressure guide valve rod, an overpressure guide valve seat, an overpressure guide valve support and an overpressure guide valve cover;

[0010] The overpressure guide valve cover is located at the top and is sealingly connected with the valve body; the overpressure guide valve seat is located at the bottom and is sealingly connected with the valve body through the overpressure guide valve support arranged above; a second cavity is formed between the overpressure guide valve cover, the valve body and the overpressure guide valve seat, and the second cavity is communicated with the adjusting cavity channel; the overpressure guide valve rod penetrates the overpressure guide valve support and the overpressure guide valve seat from top to bottom, the top is located in a first groove arranged at the bottom of the overpressure guide valve cover, and the bottom is provided with a first shoulder and located in a second groove arranged on the valve body, and the second groove is communicated with the inlet through a third inlet channel; the overpressure guide valve rod can move up and down, and a first T-shaped through hole flow channel is arranged on the rod body and can communicate the second cavity with the third inlet channel; a first cavity is formed between the valve body, the overpressure guide valve seat and the first shoulder, and the first cavity is communicated with the overpressure guide channel; an overpressure guide adjusting spring with vertical elastic force is sleeved on the overpressure guide valve rod in the first cavity; the third inlet channel can be communicated with the first cavity or the second cavity through the up and down movement of the overpressure guide valve rod.

[0011] Further, the high-pressure interval pressure reducing valve comprises a high-pressure interval valve seat, a high-pressure interval valve core, a high-pressure interval top rod sleeve, a high-pressure interval top rod and a high-pressure interval valve cover;

[0012] The high-pressure interval valve cover is located at the top and is in sealing connection with the valve body, the inner top is fixed with the high-pressure interval adjusting spring with vertical elasticity, and the lower part is provided with the high-pressure interval top rod sleeve in sealing connection with the valve body; the second stop shoulder at the top of the high-pressure interval top rod is fixed with the lower end of the high-pressure interval adjusting spring and can slide up and down in the high-pressure interval valve cover in sealing; the third chamber is formed between the second stop shoulder of the high-pressure interval top rod, the high-pressure interval valve cover and the high-pressure interval top rod sleeve, and the third chamber is communicated with the second chamber through the adjusting cavity channel; the lower part of the high-pressure interval top rod penetrates through the high-pressure interval top rod sleeve and is in sliding sealing connection therebetween, and the bottom is fixed with the high-pressure interval partition plate always located below the high-pressure interval top rod sleeve; the high-pressure interval partition plate is in sealing sliding connection with the valve body, and the lower end is provided with the first push rod structure; the fourth chamber is formed between the high-pressure interval top rod, the high-pressure interval top rod sleeve, the valve body and the high-pressure interval partition plate, and the fourth chamber is communicated with the first chamber through the overpressure guide channel; the high-pressure interval partition plate is provided below with the high-pressure interval valve core in sealing sliding connection with the valve body, the high-pressure interval partition plate and the high-pressure interval valve core are provided with the high-pressure interval partition plate adjusting spring with vertical elasticity, the high-pressure interval partition plate, the high-pressure interval valve core and the valve body jointly form the fifth chamber, and the fifth chamber is communicated with the first outlet channel; the top of the high-pressure interval valve core can be in contact with the first push rod structure, and the lower part penetrates through the high-pressure interval valve seat and is in sealing sliding connection therebetween; the high-pressure interval valve seat is in sealing connection with the valve body, and the inner cavity thereof can be communicated with the inlet through the first inlet channel; the rod body of the high-pressure interval valve core is provided with the second T-shaped through-hole flow channel for communicating the inner cavity of the high-pressure interval valve seat with the fifth chamber, and the bottom is provided with the first taper head capable of controlling whether the inner cavity of the high-pressure interval valve seat is communicated with the first inlet channel.

[0013] Further, the low-pressure interval pressure reducing valve comprises a low-pressure interval valve seat, a low-pressure interval valve core, a low-pressure interval top rod and a low-pressure interval valve cover;

[0014] The low-pressure interval valve cover is located at the bottom and is sealingly connected with the valve body, and a low-pressure interval adjusting spring with vertical elasticity is fixed inside; the top of the low-pressure interval adjusting spring is fixed with a low-pressure interval top rod which is sealingly and slidingly connected with the valve body, and a sixth chamber is formed between the low-pressure interval top rod, the low-pressure interval valve cover and the valve body, and the sixth chamber is communicated with the inlet through a second inlet channel; a low-pressure interval partition plate which is sealingly and slidingly connected with the valve body is arranged above the low-pressure interval top rod, and the low-pressure interval top rod can contact with the low-pressure interval partition plate and provide upward force; the upper end of the low-pressure interval partition plate is provided with a second push rod structure, and a low-pressure interval valve core which is sealingly and slidingly connected with the valve body is arranged above; a low-pressure interval partition plate adjusting spring with vertical elasticity is arranged between the low-pressure interval partition plate and the low-pressure interval valve core, and a seventh chamber is formed between the low-pressure interval valve core, the low-pressure interval partition plate and the valve body, and the seventh chamber is communicated with the second outlet channel; the bottom of the low-pressure interval valve core can contact with the second push rod structure, and the upper part penetrates through a low-pressure interval valve seat and is sealingly and slidingly connected with the low-pressure interval valve seat; the low-pressure interval valve seat is sealingly connected with the valve body, and the inner cavity of the low-pressure interval valve seat can be communicated with the inlet through the first inlet channel; a third T-shaped through-hole flow channel for connecting the inner cavity of the low-pressure interval valve seat with the seventh chamber is arranged on the rod body of the low-pressure interval valve core, and a second taper head for controlling whether the inner cavity of the low-pressure interval valve seat is communicated with the first inlet channel is arranged at the top of the low-pressure interval valve core.

[0015] Further, the second-stage pressure reducing valve comprises a second-stage valve cover, a second-stage valve shell, a second-stage valve core and a second-stage valve seat;

[0016] One end of the second-stage valve shell is sealingly and fixedly connected with the valve body, and the other end is connected with the second-stage valve cover; a second-stage valve seat is fixed inside the second-stage valve shell, and a second-stage valve core penetrates through the second-stage valve seat and can move left and right in the horizontal direction; the second-stage valve core has a tapered surface step structure which can match the tapered opening of the second-stage valve seat in the middle, and the flow area between the tapered surface step structure and the tapered opening can be adjusted by moving left and right; a second-stage return spring with horizontal elasticity is arranged on the left end of the second-stage valve core; one end of the second-stage return spring is pressed on the valve body, and the other end is pressed on the tapered surface step structure; a second-stage diaphragm with elasticity is arranged at the connection between the second-stage valve cover and the second-stage valve shell, and the second-stage diaphragm divides the inside of the second-stage pressure reducing valve into two cavities which are not communicated with each other; a second-stage adjusting spring with horizontal elasticity is fixed between one side of the second-stage diaphragm and the second-stage valve cover, and the other side abuts against the right end of the second-stage valve core; the second-stage adjusting spring is coaxially arranged with the second-stage valve core; openings which are respectively communicated with the first outlet channel and the second outlet channel are arranged on the second-stage valve shell which is located on the left side of the second-stage valve seat; and an outlet which is communicated with the outside is arranged on the second-stage valve shell which is located on the right side of the second-stage valve seat.

[0017] As preferred, the inlet is coaxially arranged with the outlet, the high-pressure interval pressure reducing valve and the low-pressure interval pressure reducing valve are coaxially arranged; the overpressure conduction valve, the high-pressure interval pressure reducing valve, the low-pressure interval pressure reducing valve and the second-stage pressure reducing valve are respectively arranged in the valve body through cylindrical stepped grooves to form an entirety.

[0018] As preferred, the overpressure conduction valve cover is sealingly and fixedly connected with the valve body through threads and a sealing ring, the overpressure conduction valve seat is sealingly and fixedly connected with the valve body through a sealing ring, the overpressure conduction valve stem is sealingly and slidingly connected with the valve body through a sealing ring, the first stop shoulder of the overpressure conduction valve stem is sealingly and slidingly connected with the valve body through a sealing ring, and the overpressure conduction valve stem is sealingly and slidingly connected with the overpressure conduction valve seat through a sealing ring.

[0019] One end of the overpressure conduction adjusting spring is fixed on the overpressure conduction valve seat, and the other end is fixed on the first stop shoulder of the overpressure conduction valve stem; the overpressure conduction valve stem, the overpressure conduction valve seat, the overpressure conduction adjusting spring, the overpressure conduction valve seat and the overpressure conduction valve cover are coaxially arranged; the size of the first stop shoulder of the overpressure conduction valve stem is smaller than the size of the inner cavity of the overpressure conduction valve seat, so that when the overpressure conduction valve stem moves up to completely enter the inner cavity of the overpressure conduction valve seat, the third inlet channel is communicated with the first chamber.

[0020] As preferred, the high-pressure interval valve cover is sealingly and fixedly connected with the valve body through a sealing ring, the high-pressure interval top rod sleeve is sealingly and fixedly connected with the valve body through a sealing ring, the high-pressure interval top rod is sealingly and slidingly connected with the high-pressure interval valve cover and the high-pressure interval top rod sleeve through a sealing ring, the high-pressure interval partition plate is sealingly and slidingly connected with the valve body through a sealing ring, the high-pressure interval valve core is sealingly and slidingly connected with the valve body and the high-pressure interval valve seat through a sealing ring, and the high-pressure interval valve seat is sealingly and fixedly connected with the valve body through a sealing ring.

[0021] The top end of the high-pressure interval adjusting spring is fixed on the high-pressure interval valve cover through a bolt; the first push rod structure is a plurality of vertical straight rods fixed on the bottom of the high-pressure interval partition plate in a circumferential direction; the third chamber is communicated with the adjusting cavity channel through a plurality of right-angle through holes formed in the circumferential direction on the top of the high-pressure interval top rod sleeve; the high-pressure interval valve seat, the high-pressure interval valve core, the high-pressure interval partition plate, the high-pressure interval partition plate adjusting spring, the high-pressure interval top rod sleeve, the high-pressure interval top rod, the high-pressure interval adjusting spring and the high-pressure interval valve cover are coaxially arranged.

[0022] As preferred, the low-pressure interval valve cover is sealingly and fixedly connected with the valve body through a sealing ring, the low-pressure interval top rod is sealingly and slidingly connected with the valve body through a sealing ring, the low-pressure interval partition plate is sealingly and slidingly connected with the valve body through a sealing ring, the low-pressure interval valve seat is sealingly and fixedly connected with the valve body through a sealing ring, and the low-pressure interval valve core is sealingly and slidingly connected with the valve body and the low-pressure interval valve seat through a sealing ring.

[0023] The first low-pressure interval threaded retainer and the second low-pressure interval threaded retainer fixed to the valve body are arranged between the low-pressure interval partition plate and the low-pressure interval top rod, the first low-pressure interval threaded retainer is used for limiting the lower limit position of the low-pressure interval partition plate, and the second low-pressure interval threaded retainer is used for limiting the upper limit position of the low-pressure interval top rod; the bottom end of the low-pressure interval adjusting spring is fixed to the low-pressure interval valve cover through a bolt; the second push rod structure is a plurality of vertical straight rods fixed in the circumferential direction on the top of the low-pressure interval partition plate; the low-pressure interval valve seat, the low-pressure interval valve core, the low-pressure interval partition plate adjusting spring, the low-pressure interval partition plate, the low-pressure interval top rod, the low-pressure interval adjusting spring and the low-pressure interval valve cover are coaxially arranged.

[0024] In the second aspect, the application provides a high-pressure hydrogen pressure reducing method using the high-pressure hydrogen pressure reducing valve group with high pressure regulating precision.

[0025] S1: When no hydrogen is introduced into the inlet, the high-pressure interval pressure reducing valve and the low-pressure interval pressure reducing valve are both in the closed state, and the specific process is as follows:

[0026] The overpressure guide valve rod in the overpressure guide valve is in the lower limit position under the elastic force of the overpressure guide adjusting spring, so that the third inlet channel is in communication with the second chamber and is not in communication with the first chamber; the high-pressure interval top rod in the high-pressure interval pressure reducing valve is pushed downward by the high-pressure interval adjusting spring, the high-pressure interval partition plate contacts the high-pressure interval valve core and generates a force on the high-pressure interval valve core through the first push rod structure; the first taper head at the bottom of the high-pressure interval valve core blocks the opening at the bottom of the high-pressure interval valve seat, and the first slit area between the two is closed; at the same time, the low-pressure interval valve core and the low-pressure interval partition plate of the low-pressure interval pressure reducing valve are respectively in the upper limit position and the lower limit position of the low-pressure interval partition plate under the elastic force of the low-pressure interval partition plate adjusting spring; the upper limit position of the low-pressure interval valve core refers to that the second taper head at the top of the low-pressure interval valve core blocks the opening at the top of the low-pressure interval valve seat, so that the second slit area between the two is closed; the second-stage valve core in the second-stage pressure reducing valve is kept in the open state of the third slit area between the taper face ladder structure and the tapered opening of the second-stage valve seat under the combined force of the second-stage return spring and the second-stage adjusting spring.

[0027] S2: When the gas pressure introduced from the inlet exceeds 70 MPa and reaches the rated value, the inlet reaches the overpressure state, at this time, the high-pressure interval pressure reducing valve and the low-pressure interval pressure reducing valve are both in the closed state, and the specific process is as follows:

[0028] The overpressure pilot valve stem in the overpressure pilot valve moves up to completely enter the inner cavity of the overpressure pilot valve seat under the action of the gas pressure in the third inlet channel, so that the third inlet channel is communicated with the first chamber; the gas enters the fourth chamber from the first chamber through the overpressure pilot channel, and the pressure directly acts on the high-pressure interval spacer plate; the high-pressure interval spacer plate overcomes the elastic force of the high-pressure interval spacer plate adjusting spring, moves down to contact the high-pressure interval valve core and generates a downward force on it, so that the first taper head at the bottom of the high-pressure interval valve core blocks the opening at the bottom of the high-pressure interval valve seat, and the first narrow gap is closed; at the same time, the gas enters the sixth chamber through the second inlet channel, and the gas pressure acts on the lower end surface of the low-pressure interval top rod to make it move up; because the gas pressure is greater than the elastic force of the low-pressure interval adjusting spring acting on the low-pressure interval top rod, the low-pressure interval top rod continues to move up to contact the low-pressure interval spacer plate and push it to move up; in the process of moving up of the low-pressure interval spacer plate, the second push rod structure abuts against the low-pressure interval valve core, and the second taper head blocks the opening at the top of the low-pressure interval valve seat, so that the second narrow gap between them is closed;

[0029] S3: When the gas pressure introduced from the inlet is in the high-pressure interval of 40-70 MPa, the high-pressure interval pressure relief valve is in the open state, and the low-pressure interval pressure relief valve is in the closed state, as follows:

[0030] The overpressure pilot valve stem in the overpressure pilot valve moves up but does not completely enter the inner cavity of the overpressure pilot valve seat under the action of the gas pressure in the third inlet channel, and the third inlet channel is communicated with the second chamber; the gas enters the third chamber from the second chamber through the adjusting cavity channel, and the pressure acts on the high-pressure interval top rod and is greater than the elastic force of the high-pressure interval adjusting spring, so that the high-pressure interval top rod moves up; the high-pressure interval spacer plate also moves up under the action of the elastic force of the high-pressure interval spacer plate adjusting spring, until it abuts against the high-pressure interval top rod sleeve and reaches the upper limit position; in the process of moving up of the high-pressure interval spacer plate, the high-pressure interval top rod does not generate a force on it; the elastic force on the top of the high-pressure interval valve core gradually decreases until it is less than the gas pressure introduced from the first inlet channel, the high-pressure interval valve core moves up to open the first narrow gap and generate a first throttling window; the gas enters the fifth chamber through the second T-shaped through hole flow passage of the high-pressure interval valve core, and enters the second-stage pressure relief valve through the first outlet channel;

[0031] In this process, when the gas pressure introduced from the inlet becomes larger, the force acting on the upper end surface of the high-pressure interval valve core becomes larger, the high-pressure interval valve core moves down a larger distance, and the first throttling window opening degree decreases; when the gas pressure introduced from the inlet becomes smaller, the force acting on the upper end surface of the high-pressure interval valve core becomes smaller, the high-pressure interval valve core moves down a smaller distance, and the first throttling window opening degree increases;

[0032] The gas enters the sixth chamber through the second inlet channel, and the gas pressure acts on the lower end surface of the low-pressure interval top rod to move it upward; because the gas pressure is greater than the elastic force of the low-pressure interval adjusting spring acting on the low-pressure interval top rod, the low-pressure interval top rod continues to move upward to contact the low-pressure interval partition plate and push it upward; in the process of moving the low-pressure interval partition plate upward, the second push rod structure abuts against the low-pressure interval spool, and the second taper head blocks the opening at the top of the low-pressure interval valve seat to close the second slit area between them;

[0033] S4: When the gas pressure from the inlet is in the low-pressure interval of 5-40 MP, the high-pressure interval pressure relief valve is in the closed state, and the low-pressure interval pressure relief valve is in the open state, as follows:

[0034] The gas pressure entering the overpressure conduction valve from the third inlet channel is less than the elastic force of the overpressure conduction adjusting spring, so that the third inlet channel is in communication with the second chamber and not in communication with the first chamber; the gas enters the third chamber from the second chamber through the adjusting cavity channel, and the pressure acts on the high-pressure interval top rod but the pressure is less than the elastic force of the high-pressure interval adjusting spring, so that the high-pressure interval top rod moves downward under the action of the resultant force and pushes the high-pressure interval partition plate downward; the high-pressure interval partition plate contacts the high-pressure interval spool through the first push rod structure and generates a force on it, and the first taper head at the bottom of the high-pressure interval spool blocks the opening at the bottom of the high-pressure interval valve seat to close the first slit area between them;

[0035] The gas enters the sixth chamber through the second inlet channel, and the gas pressure acts on the lower end surface of the low-pressure interval top rod; because the gas pressure acting on the low-pressure interval top rod is less than the elastic force of the low-pressure interval adjusting spring, the low-pressure interval top rod moves downward under the action of the resultant force; at the same time, the gas acts on the second taper head of the low-pressure interval spool through the first inlet channel, and because the gas pressure acting on the upper end of the low-pressure interval spool is greater than the elastic force of the low-pressure interval partition plate adjusting spring, the low-pressure interval spool moves downward to open the second slit area and generate a second throttling window; the gas enters the seventh chamber from the first inlet channel through the third T-shaped through-hole flow passage of the low-pressure interval spool, and enters the second-stage pressure relief valve through the second outlet channel;

[0036] In this process, when the gas pressure at the inlet becomes larger, the pressure acting on the lower end surface of the low-pressure interval spool becomes larger because the cross-sectional area of the second taper head is smaller than that of the bottom of the low-pressure interval top rod, the low-pressure interval spool moves upward, and the opening degree of the second throttling window decreases; when the gas pressure at the inlet becomes smaller, the pressure acting on the lower end surface of the low-pressure interval spool becomes smaller, the low-pressure interval spool moves downward, and the opening degree of the second throttling window increases;

[0037] S5: The second-stage pressure relief valve can realize dynamic adjustment of the stable outlet gas pressure, as follows:

[0038] When the gas from the first outlet channel or the second outlet channel enters the upstream area of the second stage valve housing inner cavity, passes through the third slit area and forms the third throttling window, the gas after pressure reduction enters the downstream area of the second stage valve housing inner cavity and acts on the second stage diaphragm, and finally flows out from the outlet;

[0039] In this process, when the pressure and flow of the gas entering from the first outlet channel or the second outlet channel increase, the pressure of the gas in the downstream area also gradually increases to be greater than the spring force of the second stage adjusting spring, the second stage adjusting spring is further compressed while driving the second stage diaphragm to move rightward, the second stage valve core also moves rightward, the opening degree of the third throttling window decreases, and the pressure of the gas in the downstream area correspondingly decreases, so as to generate negative feedback until the elastic force of the second stage adjusting spring and the second stage return spring is balanced with the pressure of the gas, so that the output pressure of the outlet of the downstream area is stabilized; when the pressure and flow of the gas entering from the first outlet channel or the second outlet channel decrease, the pressure of the gas in the downstream area also gradually decreases to be less than the spring force of the second stage adjusting spring, the second stage diaphragm moves leftward while driving the second stage valve core to also move leftward, the opening degree of the third throttling window increases, and the pressure of the gas in the downstream area correspondingly rises, so as to generate negative feedback until the elastic force of the second stage adjusting spring and the second stage return spring is balanced with the pressure of the gas, so that the output pressure of the outlet of the downstream area is stabilized.

[0040] Compared with the prior art, the present application has the following beneficial effects:

[0041] 1) The present application can realize compact structure of the pressure reducing valve group, integration in a single valve body, greatly reduce the leakage point, and high reliability.

[0042] 2) The present application realizes pressure reduction through pressure partition of the first stage pressure reducing valve, ensures that the single pressure reducing valve structure plays a good pressure reducing role, reduces the pressure variation interval of the valve after the first stage pressure reducing valve in the large inlet pressure variation interval working condition, improves the hydrogen pressure control precision of the second stage pressure reducing valve, and further improves the working efficiency and service life of the hydrogen fuel cell.

[0043] 3) The present application can realize overpressure protection of the pressure reducing valve group, when the inlet pressure is too large to exceed the rated pressure, the overpressure conduction valve and the adjusting cavity can ensure that the first stage pressure reducing valve is closed, the fuel cell is protected, and the safety is improved. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 It is a structure schematic view of the high-pressure hydrogen pressure reducing valve group of the present application;

[0045] Figure 2 It is a structure schematic view of the overpressure conduction valve;

[0046] Figure 3 It is a structure schematic view of the high-pressure interval pressure reducing valve;

[0047] Figure 4 This is a schematic diagram of a pressure reducing valve in the low-pressure range.

[0048] Figure 5 This is a schematic diagram of the second-stage pressure reducing valve;

[0049] Reference numerals: Valve body 1, Overpressure Activation Valve 2, High Pressure Zone Pressure Reducing Valve 3, Low Pressure Zone Pressure Reducing Valve 4, Second Stage Pressure Reducing Valve 5, Inlet 6, Outlet 7, First Inlet Channel a1, Second Inlet Channel a2, Third Inlet Channel a3, Adjustment Chamber Channel b1, Overpressure Activation Channel b2, First Outlet Channel c1, Second Outlet Channel c2, Overpressure Activation Valve Stem 2-1, Overpressure Activation Valve Seat 2-2, Overpressure Activation Adjusting Spring 2-3, Overpressure Activation Support 2-4, Overpressure Activation Valve Cover 2-5, High Pressure Zone Valve Seat 3-1, High Pressure Zone Valve Core 3-2, High Pressure Zone Partition 3-3, High Pressure Zone Partition Adjusting Spring 3-4, High Pressure Zone 3-5, high-pressure zone push rod sleeve, 3-6, high-pressure zone adjusting spring, 3-7, high-pressure zone valve cover, 3-8, low-pressure zone valve seat, 4-1, low-pressure zone valve core, 4-2, low-pressure zone partition plate adjusting spring, 4-3, low-pressure zone partition plate, 4-4, first low-pressure zone threaded retaining ring, 4-5, second low-pressure zone threaded retaining ring, 4-6, low-pressure zone push rod, 4-7, low-pressure zone adjusting spring, 4-8, low-pressure zone valve cover, 4-9, second-stage valve cover, 5-1, second-stage valve body, 5-2, second-stage return spring, 5-3, second-stage valve core, 5-4, second-stage valve seat, 5-5, second-stage diaphragm, 5-6, second-stage adjusting spring, 5-7. Detailed Implementation

[0050] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly, provided that there is no mutual conflict.

[0051] like Figure 1 As shown, this invention provides a high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy. The assembly mainly includes an overpressure valve 2 that activates when the inlet pressure is too high, a pair of primary pressure reducing valves distributed vertically, and a secondary pressure reducing valve located at the outlet. In the high inlet pressure range, the upper high-pressure range pressure reducing valve remains activated to reduce pressure, while the lower low-pressure range pressure reducing valve automatically closes under high pressure. In the low inlet pressure range, the lower low-pressure range pressure reducing valve remains activated to reduce pressure, while the upper high-pressure range pressure reducing valve automatically closes under spring action. The gas after primary pressure reduction enters the secondary pressure reducing valve, achieving secondary pressure reduction to ensure stable outlet pressure. The high-pressure range pressure reducing valve works in conjunction with the low-pressure range pressure reducing valve to achieve segmented pressure reduction, expanding the inlet pressure range and ensuring stable hydrogen pressure after pressure reduction by the valve assembly, thus adapting to the pressure drop process at the front end of the gas release from the high-pressure hydrogen storage cylinder.

[0052] Specifically, the overpressure conducting valve 2, the high-pressure interval pressure reducing valve 3, the low-pressure interval pressure reducing valve 4 and the second-stage pressure reducing valve 5 are arranged in the valve body 1 through cylindrical stepped recesses and form an integral whole. The valve body 1 is provided with an inlet 6 on one side and an outlet 7 on the other side. The air inlet at the bottom of the overpressure conducting valve 2 is communicated with the inlet 6, and the two air outlets are respectively communicated with two independent inner cavities of the high-pressure interval pressure reducing valve 3. The overpressure conducting valve 2 can control the opening and closing of the air inlet at the bottom of the high-pressure interval pressure reducing valve 3 according to the air pressure. The high-pressure interval pressure reducing valve 3 is used to open and perform first-stage pressure reduction when the air pressure is high, and the air inlet at the bottom thereof is communicated with the inlet 6, and the air outlet is communicated with the outlet 7 through the second-stage pressure reducing valve 5. The low-pressure interval pressure reducing valve 4 is used to open and perform first-stage pressure reduction when the air pressure is low, and the two independent inner cavities thereof are respectively communicated with the inlet 6 and can be controlled to open and close according to the air pressure, and the air outlet is communicated with the outlet 7 through the second-stage pressure reducing valve 5. The structure and connection mode of each valve will be described in detail below.

[0053] As shown in Figure 2 , the overpressure conducting valve 2 is arranged in the valve body 1 through a cylindrical stepped recess, and the inlet of the overpressure conducting valve 2 is located at the bottom end of the cylindrical stepped recess and is connected with the third inlet channel a3. The overpressure conducting valve 2 mainly comprises an overpressure conducting valve rod 2-1, an overpressure conducting valve seat 2-2, an overpressure conducting valve support 2-4 and an overpressure conducting valve cover 2-5. The overpressure conducting valve cover 2-5 is located at the top and is sealingly connected with the valve body 1. In this embodiment, the overpressure conducting valve cover 2-5 is connected with the valve body 1 through threads, and a sealing ring is arranged at the connection position. The overpressure conducting valve seat 2-2 is located at the bottom of the overpressure conducting valve 2 and is pressed by the overpressure conducting valve support 2-4 from above, that is, the overpressure conducting valve seat 2-2 is clamped between the overpressure conducting valve support 2-4 and the valve body 1, so as to realize the sealing connection with the valve body 1. The overpressure conducting valve support 2-4 is also sealingly connected with the valve body 1. The overpressure conducting valve cover 2-5, the valve body 1 and the overpressure conducting valve seat 2-2 form a relatively independent second cavity, and the second cavity is communicated with the adjusting cavity channel b1.

[0054] As shown in Figure 2As shown, the overpressure conduction valve rod 2-1 penetrates the overpressure conduction support 2-4 and the overpressure conduction valve seat 2-2 from top to bottom in sequence, the top is located in the first groove at the bottom of the overpressure conduction valve cover 2-5, the bottom is provided with a first shoulder and located in the second groove provided on the valve body 1, and the second groove is communicated with the inlet 6 through the third inlet channel a3. That is, the overpressure conduction valve seat 2-2, the overpressure conduction support 2-4 and the overpressure conduction valve cover 2-5 are centrally provided with a sliding groove, and the overpressure conduction valve rod 2-1 can axially slide in the sliding groove. The rod body of the overpressure conduction valve rod 2-1 is provided with a first T-shaped through hole flow channel, which can communicate the second chamber with the third inlet channel a3. Specifically, the first T-shaped through hole flow channel includes a horizontal pipe section and a vertical pipe section, the horizontal pipe section is provided on the upper part of the overpressure conduction valve rod 2-1 and can be communicated with the second chamber, one end of the vertical pipe section is communicated with the middle part of the horizontal pipe section, and the other end is located at the bottom of the overpressure conduction valve rod 2-1 and communicated with the third inlet channel a3. In this embodiment, the longitudinal cross section of the overpressure conduction valve rod 2-1 is inverted T-shaped structure, including a vertical section at the top and a horizontal section (i.e. the first shoulder) at the bottom, the size of the horizontal section is smaller than the size of the inner cavity of the overpressure conduction valve seat 2-2, so that the horizontal section can completely enter the inner cavity of the overpressure conduction valve seat 2-2. The connection between the overpressure conduction valve cover 2-5 and the overpressure conduction valve rod 2-1 is not completely sealed, but has a certain small gap, which ensures the feasibility of the up and down movement of the overpressure conduction valve rod 2-1.

[0055] As shown in the figure, Figure 2 The valve body 1, the overpressure conduction valve seat 2-2 and the first shoulder form a relatively independent first chamber, and the first chamber is communicated with the overpressure conduction channel b2. The overpressure conduction valve rod 2-1 located in the first chamber is provided with an overpressure conduction adjusting spring 2-3. The overpressure conduction adjusting spring 2-3 always has a vertical elastic force, one end of which is fixed to the overpressure conduction valve seat 2-2, and the other end is fixed to the first shoulder of the overpressure conduction valve rod 2-1. Through the up and down movement of the overpressure conduction valve rod 2-1, the third inlet channel a3 can be communicated with the first chamber or the second chamber.

[0056] In this embodiment, the overpressure conduction valve cover 2-5 is sealingly and fixedly connected with the valve body 1 through threads and a sealing ring, the overpressure conduction support 2-4 is sealingly and fixedly connected with the valve body 1 through a sealing ring, the overpressure conduction valve seat 2-2 is sealingly connected with the valve body 1 through a sealing ring, the first shoulder of the overpressure conduction valve rod 2-1 is sealingly and slidingly connected with the valve body 1 (in this application, if not specially stated, "sealingly and slidingly connected" means that the connection between the two is sealed and can slide relatively), and the overpressure conduction valve rod 2-1 is sealingly and slidingly connected with the overpressure conduction valve seat 2-2 through a sealing ring. The overpressure conduction valve rod 2-1, the overpressure conduction valve seat 2-2, the overpressure conduction adjusting spring 2-3, the overpressure conduction support 2-4 and the overpressure conduction valve cover 2-5 are coaxially arranged.

[0057] AsFigure 3 As shown, the high-pressure section pressure reducing valve 3 is disposed in the valve body 1 through a cylindrical stepped groove, and the inlet of the high-pressure section pressure reducing valve 3 is located at the bottom end of the cylindrical stepped groove and connected to the first inlet channel a1. The high-pressure section pressure reducing valve 3 mainly includes a high-pressure section valve seat 3-1, a high-pressure section valve core 3-2, a high-pressure section push rod sleeve 3-5, a high-pressure section push rod 3-6, and a high-pressure section valve cover 3-8. The high-pressure section valve cover 3-8 is located at the top and is sealed to the valve body 1, and a high-pressure section adjusting spring 3-7 with vertical elasticity is fixed inside the top. In this embodiment, the high-pressure section valve cover 3-8 is threaded to the valve body 1, and the connection is sealed by a sealing ring; the high-pressure section adjusting spring 3-7 is connected to the high-pressure section valve cover 3-8 by a set screw, and there is a small gap at the connection between the set screw and the high-pressure section valve cover 3-8 to ensure the feasibility of the high-pressure section push rod 3-6 moving up and down. A high-pressure section push rod sleeve 3-5 is provided below the high-pressure section valve cover 3-8, and the high-pressure section push rod sleeve 3-5 is sealed to the valve body 1. The second shoulder at the top of the high-pressure section push rod 3-6 is located inside the high-pressure section valve cover 3-8 and is fixed to the lower end of the high-pressure section adjusting spring 3-7. The high-pressure section push rod 3-6 can slide up and down sealed inside the high-pressure section valve cover 3-8. The second shoulder of the high-pressure section push rod 3-6, the high-pressure section valve cover 3-8, and the high-pressure section push rod sleeve 3-5 form a relatively independent third chamber, which is connected to the second chamber through the adjusting chamber channel b1. In this embodiment, the third chamber is connected to the adjusting chamber channel b1 through several right-angle through holes circumferentially opened at the top of the high-pressure section push rod sleeve 3-5.

[0058] like Figure 3 As shown, the lower part of the high-pressure section top rod 3-6 penetrates the high-pressure section top rod sleeve 3-5, and the high-pressure section top rod 3-6 and the high-pressure section top rod sleeve 3-5 are slidably and sealingly connected. A high-pressure section partition plate 3-3 is fixed to the bottom of the high-pressure section top rod 3-6. The high-pressure section partition plate 3-3 is located below the high-pressure section top rod sleeve 3-5 and is slidably and sealingly connected to the valve body 1. The high-pressure section partition plate 3-3 remains below the high-pressure section top rod sleeve 3-5 during its vertical sliding motion; that is, the upper limit position of the high-pressure section partition plate 3-3 is in contact with the bottom of the high-pressure section top rod sleeve 3-5. To achieve this effect, in this embodiment, the cross-section of the high-pressure section top rod sleeve 3-5 is set to be larger than the cross-section of the high-pressure section partition plate 3-3, thereby limiting the position of the high-pressure section partition plate 3-3. The lower end of the high-pressure section partition plate 3-3 has a first push rod structure. In this embodiment, the first push rod structure consists of several vertical straight rods circumferentially fixed to the bottom of the high-pressure section partition plate 3-3. The high-pressure section push rod 3-6, the high-pressure section push rod sleeve 3-5, the valve body 1, and the high-pressure section partition 3-3 form a relatively independent fourth chamber, which is connected to the first chamber through the overpressure conduction channel b2.

[0059] like Figure 3As shown, the high-pressure interval spacer plate 3-3 is provided below the high-pressure interval valve core 3-2, and the high-pressure interval valve core 3-2 is in sealing sliding connection with the valve body 1. The high-pressure interval spacer plate adjusting spring 3-4 is arranged between the high-pressure interval valve core 3-2 and the high-pressure interval spacer plate 3-3, and the high-pressure interval spacer plate adjusting spring 3-4 always has vertical elastic force. The high-pressure interval spacer plate 3-3, the high-pressure interval valve core 3-2 and the valve body 1 jointly constitute a relatively independent fifth chamber, and the fifth chamber is in communication with the first outlet channel c1. The top of the high-pressure interval valve core 3-2 can be in contact with the first push rod structure, and the lower part penetrates the high-pressure interval valve seat 3-1, and the high-pressure interval valve core 3-2 can vertically and sealingly slide under the limitation of the high-pressure interval valve seat 3-1. The high-pressure interval valve seat 3-1 is in sealing connection with the valve body 1, and the inner cavity thereof can be in communication with the inlet 6 through the first inlet channel a1. The stem of the high-pressure interval valve core 3-2 is provided with a second T-shaped through-hole flow channel for connecting the inner cavity of the high-pressure interval valve seat 3-1 with the fifth chamber, and the bottom is provided with a first taper head capable of controlling whether the inner cavity of the high-pressure interval valve seat 3-1 is in communication with the first inlet channel a1.

[0060] That is, the high-pressure interval valve seat 3-1 is arranged at the lower end of the high-pressure interval valve core 3-2, is connected with the valve body 1 through threads, and is centrally provided with a sliding groove; the first taper head at the bottom of the high-pressure interval valve core 3-2 axially relatively slides in the sliding groove; and the taper surface of the first taper head of the high-pressure interval valve core 3-2 can form a slit with the first inlet channel a1. Specifically, the high-pressure interval top rod 3-6 is in T-shaped structure, including a horizontal segment (i.e. a second shoulder) at the upper part and a vertical segment at the lower part, the horizontal segment is in circumferential sealing connection with the inner wall of the high-pressure interval valve cover 3-8, and the vertical segment penetrates the high-pressure interval top rod sleeve 3-5 and is connected with the high-pressure interval spacer plate 3-3 at the bottom. The second T-shaped through-hole flow channel includes a horizontal pipe segment and a vertical pipe segment, the horizontal pipe segment is arranged at the lower part of the high-pressure interval valve core 3-2 adjacent to the first taper head; one end of the vertical pipe segment is in communication with the middle part of the horizontal pipe segment, and the other end is located at the top of the high-pressure interval valve core 3-2 and is in communication with the fifth chamber.

[0061] In the embodiment, the high-pressure interval valve cover 3-8 is sealingly and fixedly connected with the valve body 1 through a sealing ring, the high-pressure interval top rod sleeve 3-5 is sealingly and fixedly connected with the valve body 1 through a sealing ring, the high-pressure interval top rod 3-6 is sealingly and slidingly connected with the high-pressure interval valve cover 3-8 and the high-pressure interval top rod sleeve 3-5 through a sealing ring, the high-pressure interval spacer plate 3-3 is sealingly and slidingly connected with the valve body 1 through a sealing ring, the high-pressure interval valve core 3-2 is sealingly and slidingly connected with the valve body 1 and the high-pressure interval valve seat 3-1 through a sealing ring, and the high-pressure interval valve seat 3-1 is sealingly and fixedly connected with the valve body 1 through a sealing ring. The top end of the high-pressure interval adjusting spring 3-7 is fixed to the high-pressure interval valve cover 3-8 through a bolt, the connection part of the bolt and the high-pressure interval valve cover 3-8 is not completely sealed, has a small gap, and ensures the feasibility of the up-down movement of the high-pressure interval top rod 3-6.

[0062] AsFigure 4 As shown, the low-pressure interval pressure-reducing valve 4 is arranged in the valve body 1 through a cylindrical stepped groove, and the inlet of the low-pressure interval pressure-reducing valve 4 is located at the high end of the cylindrical stepped groove and connected with the first inlet channel a1. The low-pressure interval pressure-reducing valve 4 mainly comprises a low-pressure interval valve seat 4-1, a low-pressure interval valve core 4-2, a low-pressure interval top rod 4-7 and a low-pressure interval valve cover 4-9. The low-pressure interval valve cover 4-9 is located at the bottom and is sealingly connected with the valve body 1, and the inside is fixed with a low-pressure interval adjusting spring 4-8, which always has a vertical elastic force. In this embodiment, the bottom end of the low-pressure interval adjusting spring 4-8 is fixed on the low-pressure interval valve cover 4-9 through a bolt. The top of the low-pressure interval adjusting spring 4-8 is fixed with the low-pressure interval top rod 4-7, which is sealingly and slidingly connected with the valve body 1. The low-pressure interval top rod 4-7, the low-pressure interval valve cover 4-9 and the valve body 1 form a relatively independent sixth chamber, and the sixth chamber is communicated with the inlet 6 through the second inlet channel a2. The low-pressure interval top rod 4-7 is provided above with a low-pressure interval partition plate 4-4, which is sealingly and slidingly connected with the valve body 1, and the low-pressure interval top rod 4-7 can contact with the low-pressure interval partition plate 4-4 and provide an upward force. The upper end of the low-pressure interval partition plate 4-4 has a second push rod structure, and the low-pressure interval valve core 4-2 is arranged above, which is sealingly and slidingly connected with the valve body 1. In this embodiment, the second push rod structure is a plurality of vertical straight rods fixed on the top of the low-pressure interval partition plate 4-4. The low-pressure interval partition plate 4-4 is provided with a low-pressure interval partition plate adjusting spring 4-3 between the low-pressure interval partition plate 4-4 and the low-pressure interval valve core 4-2, which always has a vertical elastic force. The low-pressure interval valve core 4-2, the low-pressure interval partition plate 4-4 and the valve body 1 jointly form a relatively independent seventh chamber, and the seventh chamber is communicated with the second outlet channel c2. The bottom of the low-pressure interval valve core 4-2 can contact with the second push rod structure, and the upper part penetrates through the low-pressure interval valve seat 4-1, and the low-pressure interval valve core 4-2 can sealingly slide up and down under the limitation of the low-pressure interval valve seat 4-1. The low-pressure interval valve seat 4-1 is sealingly connected with the valve body 1, and the inner cavity can be communicated with the inlet 6 through the first inlet channel a1. The rod body of the low-pressure interval valve core 4-2 is provided with a third T-shaped through-hole flow channel for communicating the inner cavity of the low-pressure interval valve seat 4-1 with the seventh chamber, and the top is provided with a second taper head for controlling whether the inner cavity of the low-pressure interval valve seat 4-1 is communicated with the first inlet channel a1.

[0063] In this embodiment, the third T-shaped through-hole flow channel comprises a horizontal pipe segment and a vertical pipe segment. The horizontal pipe segment is arranged on the upper part of the low-pressure interval valve core 4-2 adjacent to the second taper head and communicates with the inner cavity of the low-pressure interval valve seat 4-1. One end of the vertical pipe segment is communicated with the middle part of the horizontal pipe segment, and the other end is located at the bottom of the low-pressure interval valve core 4-2 and communicated with the seventh chamber.

[0064] In this embodiment, the low-pressure zone valve cover 4-9 is sealed and fixedly connected to the valve body 1 via a sealing ring; the low-pressure zone push rod 4-7 is sealed and slidably connected to the valve body 1 via a sealing ring; the low-pressure zone partition 4-4 is sealed and slidably connected to the valve body 1 via a sealing ring; the low-pressure zone valve seat 4-1 is sealed and fixedly connected to the valve body 1 via a sealing ring; and the low-pressure zone valve core 4-2 is sealed and slidably connected to the valve body 1 and the low-pressure zone valve seat 4-1 via a sealing ring. A first low-pressure zone threaded retaining ring 4-5 and a second low-pressure zone threaded retaining ring 4-6, fixed to the valve body 1, are provided between the low-pressure zone partition 4-4 and the low-pressure zone push rod 4-7. The first low-pressure zone threaded retaining ring 4-5 is used to limit the lower limit position of the low-pressure zone partition 4-4, and the second low-pressure zone threaded retaining ring 4-6 is used to limit the upper limit position of the low-pressure zone push rod 4-7. The low-pressure zone valve seat 4-1, low-pressure zone valve core 4-2, low-pressure zone partition adjusting spring 4-3, low-pressure zone partition 4-4, low-pressure zone top rod 4-7, low-pressure zone adjusting spring 4-8, and low-pressure zone valve cover 4-9 are all coaxially arranged.

[0065] like Figure 5 As shown, the second-stage pressure reducing valve 5 mainly includes a second-stage valve cover 5-1, a second-stage valve housing 5-2, a second-stage valve core 5-4, and a second-stage valve seat 5-5. The second-stage valve housing 5-2 is disposed in the valve body 1 through a cylindrical stepped groove and is fastened to the valve body 1 by screws. The narrow end of the second-stage valve housing 5-2 (i.e., Figure 5 The middle left end) has through holes on both sides, which are connected to the first outlet channel c1 and the second outlet channel c2 respectively. A recessed groove is provided at the bottom of the narrow end of the second-stage valve body 5-2. The wide end of the second-stage valve body 5-2 (i.e., the...) Figure 5The second stage valve cover 5-1 is connected with the second stage valve shell 5-2, and the second stage valve shell 5-2 is internally fixed with the second stage valve seat 5-5 which is connected with the second stage valve shell 5-2 through screw threads and has a central through hole with a tapered surface inside. The second stage valve core 5-4 penetrates the second stage valve seat 5-5 and can move left and right in the horizontal direction. The left side of the second stage valve core 5-4 is inserted into the concave groove of the second stage valve shell 5-2, the middle part has a tapered stepped structure which can match the tapered opening of the second stage valve seat 5-5, and the flow area between the tapered stepped structure and the tapered opening can be adjusted by moving left and right. The left end of the second stage valve core 5-4 is sleeved with the second stage return spring 5-3 which always has horizontal elasticity. One end of the second stage return spring 5-3 is pressed on the valve body 1, and the other end is pressed on the tapered stepped structure. The connection between the second stage valve cover 5-1 and the second stage valve shell 5-2 clamps the second stage diaphragm 5-6 which has elasticity, and the second stage diaphragm 5-6 divides the second stage pressure reducing valve 5 into two chambers which are not connected with each other. The second stage adjusting spring 5-7 which always has horizontal elasticity is fixed between one side of the second stage diaphragm 5-6 and the second stage valve cover 5-1, and the other side is provided with a gasket which abuts against the right end of the second stage valve core 5-4. The second stage adjusting spring 5-7 is coaxially arranged with the second stage valve core 5-4. The second stage adjusting spring 5-7 is arranged at the right end of the second stage diaphragm 5-6 and is connected with the second stage valve cover 5-1 through a set screw. The second stage valve shell 5-2 on the left side of the second stage valve seat 5-5 is provided with openings which are respectively connected with the first outlet channel c1 and the second outlet channel c2, and the second stage valve shell 5-2 on the right side of the second stage valve seat 5-5 is provided with an outlet 7 which is connected with the outside.

[0066] In the embodiment, the inlet 6 and the outlet 7 are coaxially arranged, and the high-pressure interval pressure reducing valve 3 and the low-pressure interval pressure reducing valve 4 are coaxially arranged. The overpressure conducting valve 2, the high-pressure interval pressure reducing valve 3, the low-pressure interval pressure reducing valve 4 and the second stage pressure reducing valve 5 are respectively arranged in the valve body 1 through cylindrical stepped grooves to form an integral whole.

[0067] In actual use, the second stage pressure reducing valve 5 can adjust the outlet pressure and flow of the second stage pressure reducing valve 3 by selecting different specifications of the second stage adjusting spring 5-7 or by changing the rotation amount of the set screw of the second stage valve cover 5-1. The overpressure conducting valve 2 can realize overpressure conducting functions with different rated inlet pressures by selecting different specifications of the overpressure conducting adjusting spring 2-3. The high-pressure interval pressure reducing valve 3 can change the lower limit of the working interval of the high-pressure interval pressure reducing valve 3 by selecting different specifications of the high-pressure interval adjusting spring 3-7 or by changing the rotation amount of the set screw of the high-pressure interval valve cover 3-8. The low-pressure interval pressure reducing valve 4 can change the upper limit of the working interval of the low-pressure interval pressure reducing valve 4 by selecting different specifications of the low-pressure interval adjusting spring 4-8 or by changing the rotation amount of the set screw of the low-pressure interval valve cover 4-9.

[0068] The high-pressure hydrogen pressure reducing method using the high-pressure hydrogen pressure reducing valve group is as follows:

[0069] S1: When no hydrogen is introduced into the inlet 6, the high-pressure interval pressure reducing valve 3 and the low-pressure interval pressure reducing valve 4 are both in a closed state, which is as follows:

[0070] The overpressure guide valve rod 2-1 in the overpressure guide valve 2 is in the lower limit position under the elastic force of the overpressure guide adjustment spring 2-3, so that the third inlet channel a3 is in communication with the second chamber and not in communication with the first chamber. The high-pressure interval top rod 3-6 in the high-pressure interval pressure reducing valve 3 is pushed downward by the high-pressure interval adjustment spring 3-7, which pushes the high-pressure interval partition plate 3-3 downward, and the high-pressure interval partition plate 3-3 contacts the high-pressure interval valve core 3-2 through the first push rod structure and generates a force on it. The first taper head at the bottom of the high-pressure interval valve core 3-2 blocks the opening at the bottom of the high-pressure interval valve seat 3-1, closing the first narrow gap between them. At the same time, the low-pressure interval valve core 4-2 and the low-pressure interval partition plate 4-4 of the low-pressure interval pressure reducing valve 4 are in their upper limit position and lower limit position respectively under the elastic force of the low-pressure interval partition plate adjustment spring 4-3. The upper limit position of the low-pressure interval valve core 4-2 means that the second taper head at the top of the low-pressure interval valve core 4-2 blocks the opening at the top of the low-pressure interval valve seat 4-1, closing the second narrow gap between them. The second-stage valve core 5-4 in the second-stage pressure reducing valve 5 is under the combined force of the second-stage return spring 5-3 and the second-stage adjustment spring 5-7, so that the third narrow gap between the taper face ladder structure of the second-stage valve core 5-4 and the tapered opening of the second-stage valve seat 5-5 is kept open.

[0071] S2: When the gas pressure introduced from the inlet 6 exceeds 70 MPa and reaches the rated value, the inlet 6 reaches the overpressure state, at which time the high-pressure interval pressure reducing valve 3 and the low-pressure interval pressure reducing valve 4 are both in a closed state, which is as follows:

[0072] The overpressure pilot valve stem 2-1 in the overpressure pilot valve 2 moves up to completely enter the inner cavity of the overpressure pilot valve seat 2-2 under the action of the gas pressure in the third inlet channel a3, so that the third inlet channel a3 is in communication with the first chamber. The gas enters the fourth chamber from the first chamber through the overpressure pilot valve channel b2, and the pressure directly acts on the high-pressure interval spacer plate 3-3. The high-pressure interval spacer plate 3-3 overcomes the elastic force of the high-pressure interval spacer plate adjusting spring 3-4, moves down to contact the high-pressure interval valve core 3-2 and generates a downward force on it, so that the first taper head at the bottom of the high-pressure interval valve core 3-2 blocks the opening at the bottom of the high-pressure interval valve seat 3-1, and the first narrow gap is closed. At the same time, the gas enters the sixth chamber through the second inlet channel a2, and the gas pressure acts on the lower end surface of the low-pressure interval top rod 4-7 to make it move up. Since the gas pressure is greater than the elastic force of the low-pressure interval adjusting spring 4-8 acting on the low-pressure interval top rod 4-7, the low-pressure interval top rod 4-7 continues to move up to contact the low-pressure interval spacer plate 4-4 and push it to move up. In the process of moving up of the low-pressure interval spacer plate 4-4, the second push rod structure abuts against the low-pressure interval valve core 4-2, and the second taper head blocks the opening at the top of the low-pressure interval valve seat 4-1, so that the second narrow gap between them is closed.

[0073] S3: When the gas pressure introduced from the inlet 6 is in the high-pressure interval of 40-70 MPa, the high-pressure interval pressure relief valve 3 is in the open state, and the low-pressure interval pressure relief valve 4 is in the closed state, as follows:

[0074] The overpressure pilot valve stem 2-1 in the overpressure pilot valve 2 moves up but does not completely enter the inner cavity of the overpressure pilot valve seat 2-2 under the action of the gas pressure in the third inlet channel a3, and the third inlet channel a3 is in communication with the second chamber. The gas enters the third chamber from the second chamber through the adjusting cavity channel b1, and the pressure acts on the high-pressure interval top rod 3-6 and the pressure is greater than the elastic force of the high-pressure interval adjusting spring 3-7, so that the high-pressure interval top rod 3-6 moves up. The high-pressure interval spacer plate 3-3 also moves up under the action of the elastic force of the high-pressure interval spacer plate adjusting spring 3-4, until it abuts against the high-pressure interval top rod sleeve 3-5 and reaches the upper limit position. In the process of moving up of the high-pressure interval spacer plate 3-3, the high-pressure interval top rod 3-6 does not generate a force on it. The elastic force on the top of the high-pressure interval valve core 3-2 gradually decreases until it is less than the gas pressure introduced from the first inlet channel a1, so that the high-pressure interval valve core 3-2 moves up to open the first narrow gap and generate a first throttling window. The gas enters the fifth chamber through the second T-shaped through hole flow passage of the high-pressure interval valve core 3-2, and enters the second-stage pressure relief valve 5 through the first outlet channel c1.

[0075] In the process, when the inlet pressure fluctuates, the high-pressure interval spacer plate 3-3 lower end cavity downstream passage pressure also fluctuates accordingly, as follows: when the gas pressure at the inlet 6 increases, the force acting on the upper end surface of the high-pressure interval valve core 3-2 increases, the high-pressure interval valve core 3-2 moves downward, the first throttling window opening decreases, and stronger throttling effect is achieved. When the gas pressure at the inlet 6 decreases, the force acting on the upper end surface of the high-pressure interval valve core 3-2 decreases, the high-pressure interval valve core 3-2 moves downward, the first throttling window opening increases, and smaller throttling effect is achieved, to achieve dynamic adjustment.

[0076] The gas enters the sixth chamber through the second inlet passage a2, and the gas pressure acts on the lower end surface of the low-pressure interval top rod 4-7 to make it move upward. Because the gas pressure is greater than the elastic force of the low-pressure interval adjusting spring 4-8 acting on the low-pressure interval top rod 4-7, the low-pressure interval top rod 4-7 continues to move upward to contact the low-pressure interval spacer plate 4-4 and push it upward. In the process of moving the low-pressure interval spacer plate 4-4 upward, the second push rod structure contacts the low-pressure interval valve core 4-2, and the second taper head seals the opening at the top of the low-pressure interval valve seat 4-1, closing the second slit area between them.

[0077] S4: When the gas pressure from the inlet 6 is in the low-pressure interval of 5-40 MP, the high-pressure interval pressure reducing valve 3 is in the closed state, and the low-pressure interval pressure reducing valve 4 is in the open state, as follows:

[0078] The gas pressure from the third inlet passage a3 into the overpressure conduction valve 2 is less than the elastic force of the overpressure conduction adjusting spring 2-3, so that the third inlet passage a3 is in communication with the second chamber and not in communication with the first chamber. The gas from the second chamber enters the third chamber through the adjusting cavity passage b1, and the pressure acts on the high-pressure interval top rod 3-6 but the pressure is less than the elastic force of the high-pressure interval adjusting spring 3-7. The high-pressure interval top rod 3-6 moves downward under the action of the resultant force and pushes the high-pressure interval spacer plate 3-3 downward. The high-pressure interval spacer plate 3-3 contacts the high-pressure interval valve core 3-2 through the first push rod structure and generates a force on it. The first taper head at the bottom of the high-pressure interval valve core 3-2 seals the opening at the bottom of the high-pressure interval valve seat 3-1, closing the first slit area between them.

[0079] The gas enters the sixth chamber through the second inlet channel a2, and the gas pressure acts on the lower end surface of the low-pressure interval top rod 4-7. Since the gas pressure acting on the low-pressure interval top rod 4-7 is less than the elastic force of the low-pressure interval adjusting spring 4-8, the low-pressure interval top rod 4-7 moves downward under the action of the resultant force. At the same time, the gas acts on the second taper head of the low-pressure interval valve core 4-2 through the first inlet channel a1. Since the gas pressure acting on the upper end of the low-pressure interval valve core 4-2 is greater than the elastic force of the low-pressure interval partition adjusting spring 4-3, the low-pressure interval valve core 4-2 moves downward to open the second slit area and form a second throttling window. The gas from the first inlet channel a1 enters the seventh chamber through the third T-shaped through-hole flow channel of the low-pressure interval valve core 4-2, and enters the second-stage pressure reducing valve 5 through the second outlet channel c2.

[0080] In this process, the downstream channel pressure acts on the lower end surface of the low-pressure interval valve core 4-2 to produce dynamic adjustment, which is the same as the adjustment of the high-pressure interval pressure reducing valve described above, as follows: When the gas pressure at the inlet 6 becomes larger, the pressure acting on the lower end surface of the low-pressure interval valve core 4-2 becomes larger due to the smaller cross-sectional area of the second taper head than the cross-sectional area of the bottom of the low-pressure interval top rod 4-7. The low-pressure interval valve core 4-2 moves upward, the opening degree of the second throttling window decreases, and stronger throttling effect is achieved. When the gas pressure at the inlet 6 becomes smaller, the pressure acting on the lower end surface of the low-pressure interval valve core 4-2 becomes smaller, and the low-pressure interval valve core 4-2 moves downward, the opening degree of the second throttling window increases, and smaller throttling effect is achieved.

[0081] S5: The second-stage pressure reducing valve 5 can achieve dynamic adjustment of the gas pressure at the outlet 7, as follows:

[0082] When the gas enters the upstream area of the second-stage valve shell 5-2 cavity from the first outlet channel c1 or the second outlet channel c2, it passes through the third slit area and forms a third throttling window. The reduced pressure gas enters the downstream area of the second-stage valve shell 5-2 cavity and acts on the second-stage diaphragm 5-6, and finally flows out from the outlet 7.

[0083] In the process, when the gas pressure and flow from the first outlet channel c1 or the second outlet channel c2 increase, the gas pressure in the downstream area also gradually increases to be greater than the spring force of the second-stage adjusting spring 5-7, the second-stage adjusting spring 5-7 is further compressed while driving the second-stage diaphragm 5-6 to move rightward, the second-stage spool 5-4 also moves rightward, the third throttling window opening degree is reduced, a stronger throttling effect is achieved, the gas pressure in the downstream area is reduced accordingly, and thus a negative feedback is generated until the spring force of the second-stage adjusting spring 5-7 and the second-stage return spring 5-3 is balanced with the gas pressure, so that the output pressure of the downstream area outlet 7 is stabilized. When the gas pressure and flow from the first outlet channel c1 or the second outlet channel c2 decrease, the gas pressure in the downstream area also gradually decreases to be less than the spring force of the second-stage adjusting spring 5-7, the second-stage diaphragm 5-6 moves leftward while driving the second-stage spool 5-4 to also move leftward, the third throttling window opening degree is increased, a smaller throttling effect is achieved, the gas pressure in the downstream area is increased accordingly, and thus a negative feedback is generated until the spring force of the second-stage adjusting spring 5-7 and the second-stage return spring 5-3 is balanced with the gas pressure, so that the output pressure of the downstream area outlet 7 is stabilized. In addition, by adjusting the screwing amount of the locking screw, the spring force can be changed, and a corresponding balance state can be obtained according to the output pressure and flow demand.

[0084] The above-described embodiments are only a preferred solution of the present application, and are not used to limit the present application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. A high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy, characterized in that, The valve body (1) includes an overpressure control valve (2), a high-pressure zone pressure reducing valve (3), a low-pressure zone pressure reducing valve (4), and a second-stage pressure reducing valve (5) installed on the valve body (1). The valve body (1) has an inlet (6) on one side and an outlet (7) on the other side. The bottom inlet of the overpressure control valve (2) is connected to the inlet (6), and the two outlets are respectively connected to the two independent inner cavities of the high-pressure zone pressure reducing valve (3), which are used to control the opening and closing of the bottom inlet of the high-pressure zone pressure reducing valve (3) according to the air pressure. The high-pressure zone pressure reducing valve (3) is used to open for first-stage pressure reduction when the pressure is high. Its bottom inlet is connected to the inlet (6), and its outlet is connected to the outlet (7) through the second-stage pressure reducing valve (5). The low-pressure zone pressure reducing valve (4) is used to open for first-stage pressure reduction when the pressure is low. Its two independent inner cavities are respectively connected to the inlet (6), which can control the opening and closing according to the air pressure. Its outlet is connected to the outlet (7) through the second-stage pressure reducing valve (5).

2. The high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy according to claim 1, characterized in that, The overpressure control valve (2) includes an overpressure control valve stem (2-1), an overpressure control valve seat (2-2), an overpressure control support (2-4), and an overpressure control valve cover (2-5); The overpressure conduction valve cover (2-5) is located at the top and is sealed to the valve body (1); the overpressure conduction valve seat (2-2) is located at the bottom and is sealed to the valve body (1) through the overpressure conduction support (2-4) pressed on above; a second chamber is formed between the overpressure conduction valve cover (2-5), the valve body (1) and the overpressure conduction valve seat (2-2), and the second chamber is connected to the regulating chamber channel (b1); the overpressure conduction valve stem (2-1) passes through the overpressure conduction support (2-4) and the overpressure conduction valve seat (2-2) from top to bottom, with its top located in the first groove opened at the bottom of the overpressure conduction valve cover (2-5), and its bottom provided with a first shoulder and located in the second groove opened on the valve body (1). In the groove, the second groove is connected to the inlet (6) through the third inlet channel (a3); the overpressure conduction valve stem (2-1) can move up and down, and the stem body is provided with a first T-shaped through-hole flow channel that can connect the second chamber with the third inlet channel (a3); a first chamber is formed between the valve body (1), the overpressure conduction valve seat (2-2) and the first shoulder, and the first chamber is connected to the overpressure conduction channel (b2); an overpressure conduction adjusting spring (2-3) with vertical elasticity is sleeved on the overpressure conduction valve stem (2-1) located in the first chamber; by moving the overpressure conduction valve stem (2-1) up and down, the third inlet channel (a3) ​​can be connected to the first chamber or the second chamber.

3. A high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy according to claim 2, characterized in that, The high-pressure section pressure reducing valve (3) includes a high-pressure section valve seat (3-1), a high-pressure section valve core (3-2), a high-pressure section push rod sleeve (3-5), a high-pressure section push rod (3-6), and a high-pressure section valve cover (3-8); The high-pressure section valve cover (3-8) is located at the top and is sealed to the valve body (1). A high-pressure section adjusting spring (3-7) with a constant vertical elastic force is fixed inside the top. A high-pressure section push rod sleeve (3-5) is provided below and is sealed to the valve body (1). The second shoulder at the top of the high-pressure section push rod (3-6) is fixed to the lower end of the high-pressure section adjusting spring (3-7) and can slide up and down sealed within the high-pressure section valve cover (3-8). The second shoulder of the high-pressure section push rod (3-6), the high-pressure section valve cover (3-8), and the high-pressure section push rod sleeve (3-5) are... The three chambers form a third chamber, which is connected to the second chamber through the regulating chamber channel (b1); the lower part of the high-pressure section push rod (3-6) passes through the high-pressure section push rod sleeve (3-5) and the two are slidably sealed together, and the bottom is fixed with a high-pressure section partition plate (3-3) that is always located below the high-pressure section push rod sleeve (3-5); the high-pressure section partition plate (3-3) is slidably sealed to the valve body (1), and has a first push rod structure at its lower end; the high-pressure section push rod (3-6), the high-pressure section push rod sleeve (3-5), the valve body (1) and the high-pressure section partition plate (3-3) are connected in a sealed manner. The high-pressure zone partition (3-3) forms a fourth chamber, which is connected to the first chamber via an overpressure conduction channel (b2). Below the high-pressure zone partition (3-3) is a high-pressure zone valve core (3-2) that is slidably and sealingly connected to the valve body (1). A high-pressure zone partition adjusting spring (3-4) with a constant vertical elastic force is pressed between the high-pressure zone valve core (3-2) and the high-pressure zone partition (3-3). The high-pressure zone partition (3-3), the high-pressure zone valve core (3-2), and the valve body (1) together form a fifth chamber, which is connected to the first outlet channel (c1). The top of the core (3-2) can contact the first push rod structure, and the lower part passes through the high-pressure section valve seat (3-1) and the two are sealed and slidably connected; the high-pressure section valve seat (3-1) is sealed and connected to the valve body (1), and its inner cavity can be connected to the inlet (6) through the first inlet channel (a1); the rod of the high-pressure section valve core (3-2) is provided with a second T-shaped through hole flow channel for connecting the inner cavity of the high-pressure section valve seat (3-1) with the fifth chamber, and the bottom is provided with a first cone head that can control whether the inner cavity of the high-pressure section valve seat (3-1) is connected to the first inlet channel (a1).

4. A high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy according to claim 3, characterized in that, The low-pressure range pressure reducing valve (4) includes a low-pressure range valve seat (4-1), a low-pressure range valve core (4-2), a low-pressure range push rod (4-7), and a low-pressure range valve cover (4-9); The low-pressure zone valve cover (4-9) is located at the bottom and is sealed to the valve body (1). A low-pressure zone adjusting spring (4-8) with vertical elasticity is fixed inside. A low-pressure zone push rod (4-7) is fixed at the top of the low-pressure zone adjusting spring (4-8) and is sealed to the valve body (1). The low-pressure zone push rod (4-7), the low-pressure zone valve cover (4-9), and the valve body (1) form a sixth chamber. The sixth chamber is connected to the inlet (6) through the second inlet channel (a2). A low-pressure zone partition plate (4-4) is provided above the low-pressure zone push rod (4-7) and is sealed to the valve body (1). The low-pressure zone push rod (4-7) can contact the low-pressure zone partition plate (4-4) and provide an upward force. The upper end of the low-pressure zone partition plate (4-4) has a second push rod structure. A low-pressure zone valve core (4-2) is provided above the low-pressure zone partition plate (4-4) and is sealed to the valve body (1). A low-pressure zone partition adjusting spring (4-3) with vertical elasticity is pressed between (4-2) and the low-pressure zone partition (4-4). The low-pressure zone valve core (4-2), the low-pressure zone partition (4-4), and the valve body (1) together form the seventh chamber, which is connected to the second outlet channel (c2). The bottom of the low-pressure zone valve core (4-2) can contact the second push rod structure, and the upper part passes through the low-pressure zone valve seat (4-1) and the two are sealed and slidably connected. The low-pressure zone valve seat (4-1) is sealed and connected to the valve body (1), and its inner cavity can be connected to the inlet (6) through the first inlet channel (a1). The rod of the low-pressure zone valve core (4-2) is provided with a third T-shaped through hole flow channel for connecting the inner cavity of the low-pressure zone valve seat (4-1) with the seventh chamber, and the top is provided with a second cone head that can control whether the inner cavity of the low-pressure zone valve seat (4-1) is connected to the first inlet channel (a1).

5. A high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy according to claim 4, characterized in that, The second-stage pressure reducing valve (5) includes a second-stage valve cover (5-1), a second-stage valve body (5-2), a second-stage valve core (5-4), and a second-stage valve seat (5-5); One end of the second-stage valve housing (5-2) is sealed and fixedly connected to the valve body (1), and the other end is connected to the second-stage valve cover (5-1); a second-stage valve seat (5-5) is fixed inside the second-stage valve housing (5-2), and a second-stage valve core (5-4) passes through the second-stage valve seat (5-5) and can move left and right in the horizontal direction; the middle part of the second-stage valve core (5-4) has a conical stepped structure that matches the conical opening of the second-stage valve seat (5-5), and the flow area between it and the conical opening can be adjusted by moving left and right; a second-stage return spring (5-3) with horizontal elasticity is sleeved on the left end of the second-stage valve core (5-4); one end of the second-stage return spring (5-3) is pressed on the valve body (1), and the other end is pressed on the conical stepped structure; the second-stage valve cover (5-1) and the second-stage valve core (5-2) are connected to the valve body (1) and the valve cover (5-1) are connected to the valve cover (1) and the valve cover (5-1) are connected to the valve cover (1) and the valve cover (5-2) are connected to the valve body ... A second-stage diaphragm (5-6) with elasticity is pressed at the connection of the first-stage valve body (5-2). The second-stage diaphragm (5-6) divides the interior of the second-stage pressure reducing valve (5) into two non-communicating chambers. A second-stage adjusting spring (5-7) with horizontal elasticity is fixed between one side of the second-stage diaphragm (5-6) and the second-stage valve cover (5-1), and the other side abuts against the right end of the second-stage valve core (5-4). The second-stage adjusting spring (5-7) and the second-stage valve core (5-4) are coaxially arranged. An opening is opened on the second-stage valve body (5-2) located to the left of the second-stage valve seat (5-5) to communicate with the first outlet channel (c1) and the second outlet channel (c2) respectively. An outlet (7) communicating with the outside is opened on the second-stage valve body (5-2) located to the right of the second-stage valve seat (5-5).

6. A high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy according to claim 1, characterized in that, The inlet (6) and outlet (7) are coaxially arranged, and the high-pressure zone pressure reducing valve (3) and the low-pressure zone pressure reducing valve (4) are coaxially arranged; the overpressure conduction valve (2), the high-pressure zone pressure reducing valve (3), the low-pressure zone pressure reducing valve (4) and the second-stage pressure reducing valve (5) are all arranged in the valve body (1) through cylindrical stepped grooves to form a whole.

7. A high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy according to claim 2, characterized in that, The overpressure conduction valve cover (2-5) is sealed and fixedly connected to the valve body (1) by threads and a sealing ring. The overpressure conduction support (2-4) is fixedly and sealedly connected to the valve body (1) by a sealing ring. The overpressure conduction valve seat (2-2) is sealed and connected to the valve body (1) by a sealing ring. The first shoulder of the overpressure conduction valve stem (2-1) is sealed and slidably connected to the valve body (1) by a sealing ring. The overpressure conduction valve stem (2-1) is sealed and slidably connected to the overpressure conduction valve seat (2-2) by a sealing ring. One end of the overpressure conduction adjusting spring (2-3) is fixed to the overpressure conduction valve seat (2-2), and the other end is fixed to the first shoulder of the overpressure conduction valve stem (2-1). The overpressure conduction valve stem (2-1), the overpressure conduction valve seat (2-2), the overpressure conduction adjusting spring (2-3), the overpressure conduction support (2-4), and the overpressure conduction valve cover (2-5) are all coaxially arranged. The size of the first shoulder of the overpressure conduction valve stem (2-1) is smaller than the size of the inner cavity of the overpressure conduction valve seat (2-2), so that when the overpressure conduction valve stem (2-1) moves up to fully enter the inner cavity of the overpressure conduction valve seat (2-2), the third inlet channel (a3) ​​communicates with the first chamber.

8. A high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy according to claim 3, characterized in that, The high-pressure section valve cover (3-8) is sealed and fixedly connected to the valve body (1) through a sealing ring. The high-pressure section push rod sleeve (3-5) is sealed and fixedly connected to the valve body (1) through a sealing ring. The high-pressure section push rod (3-6) is sealed and slidably connected to the high-pressure section valve cover (3-8) and the high-pressure section push rod sleeve (3-5) through a sealing ring. The high-pressure section partition plate (3-3) is sealed and slidably connected to the valve body (1) through a sealing ring. The high-pressure section valve core (3-2) is sealed and slidably connected to the valve body (1) and the high-pressure section valve seat (3-1) through a sealing ring. The high-pressure section valve seat (3-1) is sealed and fixedly connected to the valve body (1) through a sealing ring. The top end of the high-pressure zone adjusting spring (3-7) is fixed to the high-pressure zone valve cover (3-8) by bolts; the first push rod structure is a number of vertical straight rods circumferentially fixed to the bottom of the high-pressure zone partition plate (3-3); the third chamber is connected to the adjusting chamber channel (b1) through a number of right-angle through holes circumferentially opened on the top of the high-pressure zone top rod sleeve (3-5); the high-pressure zone valve seat (3-1), high-pressure zone valve core (3-2), high-pressure zone partition plate (3-3), high-pressure zone partition plate adjusting spring (3-4), high-pressure zone top rod sleeve (3-5), high-pressure zone top rod (3-6), high-pressure zone adjusting spring (3-7) and high-pressure zone valve cover (3-8) are all coaxially arranged.

9. A high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy according to claim 4, characterized in that, The low-pressure zone valve cover (4-9) is sealed and fixedly connected to the valve body (1) through a sealing ring, the low-pressure zone top rod (4-7) is sealed and slidably connected to the valve body (1) through a sealing ring, the low-pressure zone partition plate (4-4) is sealed and slidably connected to the valve body (1) through a sealing ring, the low-pressure zone valve seat (4-1) is sealed and fixedly connected to the valve body (1) through a sealing ring, and the low-pressure zone valve core (4-2) is sealed and slidably connected to the valve body (1) and the low-pressure zone valve seat (4-1) through a sealing ring; A first low-pressure zone threaded retaining ring (4-5) and a second low-pressure zone threaded retaining ring (4-6) fixed to the valve body (1) are provided between the low-pressure zone partition plate (4-4) and the low-pressure zone top rod (4-7). The first low-pressure zone threaded retaining ring (4-5) is used to limit the lower limit position of the low-pressure zone partition plate (4-4), and the second low-pressure zone threaded retaining ring (4-6) is used to limit the upper limit position of the low-pressure zone top rod (4-7); the low-pressure zone adjusting spring The bottom end of the spring (4-8) is fixed to the low-pressure zone valve cover (4-9) by bolts; the second push rod structure is a number of vertical rods circumferentially fixed to the top of the low-pressure zone partition (4-4); the low-pressure zone valve seat (4-1), the low-pressure zone valve core (4-2), the low-pressure zone partition adjusting spring (4-3), the low-pressure zone partition (4-4), the low-pressure zone top rod (4-7), the low-pressure zone adjusting spring (4-8), and the low-pressure zone valve cover (4-9) are all coaxially arranged.

10. A method for reducing high-pressure hydrogen pressure using the high-pressure hydrogen pressure reducing valve assembly with high pressure regulation accuracy as described in claim 5, characterized in that, Specifically as follows: S1: When hydrogen is not introduced into the inlet (6), both the high-pressure zone pressure reducing valve (3) and the low-pressure zone pressure reducing valve (4) are closed, as follows: The overpressure valve stem (2-1) in the overpressure valve (2) is in the lower limit position under the elastic force of the overpressure regulating spring (2-3), so that the third inlet channel (a3) ​​is connected to the second chamber but not to the first chamber; the high pressure section push rod (3-6) in the high pressure section pressure reducing valve (3) is pushed down by the elastic force of the high pressure section regulating spring (3-7), and the high pressure section partition plate (3-3) contacts the high pressure section valve core (3-2) through the first push rod structure and exerts force on it; the first cone at the bottom of the high pressure section valve core (3-2) blocks the opening at the bottom of the high pressure section valve seat (3-1), closing the first slit area between the two; At this time, the low-pressure zone valve core (4-2) and the low-pressure zone partition plate (4-4) of the low-pressure zone pressure reducing valve (4) are respectively in their upper limit position and lower limit position under the elastic force of the low-pressure zone partition plate adjusting spring (4-3); the upper limit position of the low-pressure zone valve core (4-2) means that the second cone head at its top blocks the opening at the top of the low-pressure zone valve seat (4-1), so that the second slit area between the two is closed; the second stage valve core (5-4) in the second stage pressure reducing valve (5) is kept open under the combined force of the second stage return spring (5-3) and the second stage adjusting spring (5-7); the third slit area between the conical stepped structure and the conical opening of the second stage valve seat (5-5) is kept open. S2: When the gas pressure introduced from the inlet (6) exceeds 70MPa and reaches the rated value, the inlet (6) reaches the overpressure state. At this time, the high-pressure zone pressure reducing valve (3) and the low-pressure zone pressure reducing valve (4) are both in the closed state, as follows: Under the pressure of the gas introduced through the third inlet channel (a3), the overpressure valve stem (2-1) in the overpressure valve (2) moves upward until it fully enters the inner cavity of the overpressure valve seat (2-2), making the third inlet channel (a3) ​​connected to the first chamber; the gas enters the fourth chamber from the first chamber through the overpressure channel (b2), and the pressure acts directly on the high-pressure zone partition (3-3); the high-pressure zone partition (3-3) overcomes the elastic force of the high-pressure zone partition adjusting spring (3-4), moves downward to contact the high-pressure zone valve core (3-2), and exerts a downward force on it. The first cone at the bottom of the high-pressure section valve core (3-2) blocks the opening at the bottom of the high-pressure section valve seat (3-1), closing the first slit area. At the same time, gas enters the sixth chamber through the second inlet channel (a2), and the gas pressure acts on the lower end face of the low-pressure section push rod (4-7), causing it to move upward. Since the gas pressure is greater than the elastic force of the low-pressure section adjusting spring (4-8) acting on the low-pressure section push rod (4-7), the low-pressure section push rod (4-7) continues to move upward until it contacts the low-pressure section partition plate (4-4), and pushes the low-pressure section partition plate (4-4) upward. During the upward movement of the low-pressure zone partition plate (4-4), the second push rod structure abuts against the low-pressure zone valve core (4-2), and the second cone head blocks the opening at the top of the low-pressure zone valve seat (4-1), thus closing the second slit area between the two. S3: When the gas pressure introduced from the inlet (6) is in the high pressure range of 40-70MPa, the high pressure range pressure reducing valve (3) is in the open state, and the low pressure range pressure reducing valve (4) is in the closed state, as follows: The overpressure valve stem (2-1) in the overpressure valve (2) moves upward under the pressure of the gas introduced through the third inlet channel (a3), but does not completely enter the inner cavity of the overpressure valve seat (2-2). The third inlet channel (a3) ​​is connected to the second chamber. Gas enters the third chamber from the second chamber through the regulating chamber channel (b1). The pressure acts on the high-pressure section push rod (3-6) and is greater than the elastic force of the high-pressure section regulating spring (3-7). The high-pressure section push rod (3-6) moves upward. The high-pressure section partition (3-3) also moves upward under the elastic force of the high-pressure section partition regulating spring (3-4). The high-pressure section push rod sleeve (3-5) is in the upper limit position when it abuts against the high-pressure section push rod sleeve (3-5); during the upward movement of the high-pressure section partition plate (3-3), the high-pressure section push rod (3-6) does not exert force on it; the elastic force on the top of the high-pressure section valve core (3-2) gradually decreases until it is less than the gas pressure entering from the first inlet channel (a1), and the high-pressure section valve core (3-2) moves upward to open the first slit area, creating the first throttling window; the gas enters the fifth chamber through the second T-shaped through-hole flow channel of the high-pressure section valve core (3-2), and enters the second-stage pressure reducing valve (5) through the first outlet channel (c1); During this process, when the gas pressure introduced at the inlet (6) increases, the force acting on the upper end face of the high-pressure section valve core (3-2) increases, the downward movement distance of the high-pressure section valve core (3-2) increases, and the opening of the first throttling window decreases; when the gas pressure introduced at the inlet (6) decreases, the force acting on the upper end face of the high-pressure section valve core (3-2) decreases, the downward movement distance of the high-pressure section valve core (3-2) decreases, and the opening of the first throttling window increases. Gas enters the sixth chamber through the second inlet channel (a2). The gas pressure acts on the lower end face of the low-pressure zone push rod (4-7), causing it to move upward. Since the gas pressure is greater than the elastic force of the low-pressure zone adjusting spring (4-8) acting on the low-pressure zone push rod (4-7), the low-pressure zone push rod (4-7) continues to move upward until it contacts the low-pressure zone partition plate (4-4), and pushes the low-pressure zone partition plate (4-4) upward. During the upward movement of the low-pressure zone partition plate (4-4), the second push rod structure abuts against the low-pressure zone valve core (4-2), and the second cone head blocks the opening at the top of the low-pressure zone valve seat (4-1), thus closing the second slit area between the two. S4: When the gas pressure introduced from the inlet (6) is in the low-pressure range of 5-40MP, the high-pressure range pressure reducing valve (3) is closed and the low-pressure range pressure reducing valve (4) is open, as follows: The gas pressure entering the overpressure conduction valve (2) from the third inlet channel (a3) ​​is less than the elastic force of the overpressure conduction regulating spring (2-3), so that the third inlet channel (a3) ​​is connected to the second chamber but not to the first chamber; the gas enters the third chamber from the second chamber through the regulating chamber channel (b1), and the pressure acts on the high pressure section push rod (3-6) but is less than the elastic force of the high pressure section regulating spring (3-7). Under the combined force, the high pressure section push rod (3-6) moves down and pushes the high pressure section partition plate (3-3) down; the high pressure section partition plate (3-3) contacts the high pressure section valve core (3-2) through the first push rod structure and exerts force on it. The first cone at the bottom of the high pressure section valve core (3-2) blocks the opening at the bottom of the high pressure section valve seat (3-1) and closes the first slit area between the two; Gas enters the sixth chamber through the second inlet channel (a2), and the gas pressure acts on the lower end face of the low-pressure zone push rod (4-7). Since the gas pressure acting on the low-pressure zone push rod (4-7) is less than the elastic force of the low-pressure zone adjusting spring (4-8), the low-pressure zone push rod (4-7) moves downward under the action of the resultant force. At the same time, gas acts on the second cone of the low-pressure zone valve core (4-2) through the first inlet channel (a1). Since the gas pressure acting on the upper end of the low-pressure zone valve core (4-2) is greater than the elastic force of the low-pressure zone partition adjusting spring (4-3), the low-pressure zone valve core (4-2) moves downward to open the second slit zone and generate the second throttling window. Gas enters the seventh chamber from the first inlet channel (a1) through the third T-shaped through-hole of the low-pressure zone valve core (4-2) and enters the second-stage pressure reducing valve (5) through the second outlet channel (c2). During this process, when the gas pressure introduced at the inlet (6) increases, since the cross-sectional area of ​​the second cone is smaller than the cross-sectional area of ​​the bottom of the low-pressure zone top rod (4-7), the pressure acting on the lower end face of the low-pressure zone valve core (4-2) becomes greater, the low-pressure zone valve core (4-2) moves upward, and the opening of the second throttling window decreases; when the gas pressure introduced at the inlet (6) decreases, the pressure acting on the lower end face of the low-pressure zone valve core (4-2) decreases, the low-pressure zone valve core (4-2) moves downward, and the opening of the second throttling window increases. S5: The second-stage pressure reducing valve (5) can achieve dynamic regulation of the outlet (7) gas pressure, as detailed below: When the gas enters the upstream region of the inner cavity of the second-stage valve body (5-2) from the first outlet channel (c1) or the second outlet channel (c2), it passes through the third slit area and forms the third throttling window. The depressurized gas enters the downstream region of the inner cavity of the second-stage valve body (5-2) and acts on the second-stage diaphragm (5-6), and finally flows out from the outlet (7). During this process, when the gas pressure and flow rate entering from the first outlet channel (c1) or the second outlet channel (c2) increase, the gas pressure in the downstream region also gradually increases until it exceeds the spring force of the second-stage regulating spring (5-7). The second-stage regulating spring (5-7) is further compressed, simultaneously driving the second-stage diaphragm (5-6) to move to the right. The second-stage valve core (5-4) also moves to the right, reducing the opening of the third throttling window. Consequently, the gas pressure in the downstream region decreases, generating negative feedback until the elastic force of the second-stage regulating spring (5-7) and the second-stage return spring (5-3) balances with the gas pressure, thus allowing the downstream region to exit. (7) The output pressure is stabilized; when the gas pressure and flow rate entering from the first outlet channel (c1) or the second outlet channel (c2) decrease, the gas pressure in the downstream area also gradually decreases to less than the spring force of the second stage regulating spring (5-7). The second stage diaphragm (5-6) moves to the left and drives the second stage valve core (5-4) to move to the left, which increases the opening of the third throttling window and the gas pressure in the downstream area rises accordingly, thereby generating negative feedback until the elastic force of the second stage regulating spring (5-7) and the second stage reset spring (5-3) is balanced with the gas pressure, so that the output pressure of the downstream area outlet (7) is stabilized.

Images