Oil pressure differential valve with temperature compensation

Abstract

The application relates to an oil hydrogen pressure difference valve with temperature compensation, which comprises a valve assembly, an execution cavity is arranged on the valve assembly, the execution cavity is divided into a first cavity and a second cavity by a pressure difference sensing execution piece, the pressure difference sensing execution piece is in transmission connection with the valve assembly, a spring box is fixedly connected to one side of the execution cavity away from the valve assembly, a spring abutting against the pressure difference sensing execution piece is arranged in the spring box, a push rod is slidably arranged on the top of the spring box, an adjusting nut is threadedly connected to the push rod, a compensation piston is movably arranged in the push rod, a compensation adjusting assembly is arranged at the end of the push rod away from the spring box, and the compensation adjusting assembly is sealingly connected with a temperature bag for sensing oil temperature through a connecting pipe; the pure mechanical temperature compensation mechanism formed by the temperature bag, the compensation adjusting assembly and the compensation piston can respond to the oil temperature change of sealing oil in real time, dynamically adjust the spring pre-tightening force, and offset the effective pressure difference deviation caused by the oil temperature-induced sealing oil viscosity and system flow resistance change.

Description

Technical Field

[0001] This invention relates to the field of differential pressure valve technology, and specifically to an oil-hydrogen differential pressure valve with temperature compensation. Background Technology

[0002] Currently, in China's large-capacity thermal and nuclear power generation sectors, salient-pole synchronous steam turbine generator sets commonly use hydrogen as the cooling medium for the generator rotor. Compared to air cooling, hydrogen has significant advantages such as high thermal conductivity, low density, and low ventilation losses, which can greatly improve the cooling efficiency and operating economy of the generator set, making it the mainstream cooling solution for large-capacity generator sets. To prevent high-pressure hydrogen from leaking from the shaft end gap between the rotor and the end cover, the generator set must be equipped with a shaft end sealing oil system. Its core working principle is to continuously inject sealing oil with a pressure higher than the hydrogen pressure inside the machine into the shaft end sealing tile, forming a stable pressure oil film between the sealing tile and the shaft, achieving reliable sealing of the dynamic and static gaps, and preventing hydrogen leakage and air infiltration into the machine.

[0003] The oil-hydrogen differential pressure valve is a core control component of the sealing oil system. Its core function is to maintain the set pressure difference between the sealing oil supply pressure and the hydrogen pressure inside the generator in real time, making it a key device to ensure the safe and stable operation of the generator set. Currently, the oil-hydrogen differential pressure valves widely used in the industry are mainly of the mechanical force balance type, consisting of a valve assembly, a differential pressure sensing element, a balance spring, and a manual adjustment mechanism. Its working principle is as follows: the sealing oil pressure and the hydrogen pressure are introduced to both sides of the differential pressure sensing element, so that the differential pressure sensing element is subjected to an axial force corresponding to the actual oil-hydrogen pressure difference. This force is balanced by the preload of the balance spring. When the actual oil-hydrogen pressure difference deviates from the set value, the force balance is broken, and the differential pressure sensing element generates axial displacement, which simultaneously drives the valve core to adjust the valve flow cross-sectional area, correct the sealing oil supply pressure, and ultimately bring the oil-hydrogen pressure difference back to the set range.

[0004] The conventional oil-hydrogen differential pressure valve described above can meet basic differential pressure control requirements under stable sealing oil temperature conditions. However, during actual generator start-up, shutdown, and variable load operation, oil temperature changes significantly interfere with the accuracy of differential pressure control, making it unsuitable for all operating conditions. The sealing oil often uses turbine oil from the same source as the turbine lubricating oil system. Its kinematic viscosity exhibits significant non-linear characteristics with temperature changes; viscosity increases sharply as oil temperature decreases and decreases significantly as oil temperature increases. This viscosity change directly alters the flow resistance in the sealing oil system pipelines and the internal flow field resistance of the sealing pads, resulting in a significant deviation between the actual effective oil-hydrogen differential pressure at the sealing pads and the valve's set differential pressure. Conventional mechanically balanced oil-hydrogen differential pressure valves can only respond to the pressure difference between the oil and hydrogen sides and cannot detect changes in flow resistance and effective differential pressure shifts caused by oil temperature changes. Under different operating conditions such as cold start-up, low load, and full load, the oil temperature fluctuates greatly, easily leading to actual oil-hydrogen differential pressure exceeding the design allowable range. When the actual pressure difference is too low, there is a safety risk of hydrogen leakage along the shaft end; when the actual pressure difference is too high, a large amount of sealing oil may enter the generator, resulting in a decrease in the purity of hydrogen inside the generator and moisture in the stator winding insulation, affecting the safe and stable operation of the unit. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an oil-hydrogen differential pressure valve with temperature compensation.

[0006] The objective of this invention can be achieved through the following technical solution: A temperature-compensated oil-hydrogen differential pressure valve includes a valve assembly, an actuation chamber on the valve assembly, the actuation chamber being divided into a first chamber and a second chamber by a differential pressure sensing actuator, the differential pressure sensing actuator being drively connected to the valve assembly; a spring box is fixedly connected to the side of the actuation chamber away from the valve assembly, the spring box containing a spring that abuts against the differential pressure sensing actuator, a push rod slidingly passing through the top of the spring box, an adjusting nut being threadedly connected to the push rod, the adjusting nut being rotatably engaged with the spring box; a compensation piston is movably disposed within the push rod, the piston rod of the compensation piston abutting against the end of the spring away from the differential pressure sensing actuator, a compensation adjustment assembly is disposed at the end of the push rod away from the spring box, the compensation adjustment assembly being sealed and connected to a temperature sensor for sensing oil temperature via a connecting pipe.

[0007] Preferably, the compensation adjustment assembly includes a cylinder body, an adjustment chamber on one side of the cylinder body, an adjustment piston inside the adjustment chamber, a piston rod of the adjustment piston being threadedly connected to the cylinder body, and a handwheel being provided at the end of the piston rod of the adjustment piston away from the adjustment chamber.

[0008] Preferably, the top of the spring box has a countersunk hole for installing an adjusting nut, the bottom of the adjusting nut has an extension that extends into the countersunk hole, the outer periphery of the extension has a limiting groove, a retaining spring is provided in the limiting groove, and thrust bearings are provided on both sides of the retaining spring. A clamping nut that abuts against the thrust bearing is threaded into the countersunk hole.

[0009] Preferably, the push rod includes a threaded section and a smooth section. The threaded section is threadedly engaged with the adjusting nut, and the smooth section slides through the top of the spring box. A sealing ring is provided between the smooth section and the spring box.

[0010] Preferably, the end of the push rod near the threaded section has an integrally formed hollow anti-rotation retaining part.

[0011] Preferably, the end of the spring away from the differential pressure sensing actuator is provided with a spring seat, and the piston rod end of the compensating piston is provided with a tip that abuts against the spring seat.

[0012] Preferably, the valve assembly includes a valve body, a valve stem is movably inserted through the valve body, one end of the valve stem is connected to a differential pressure sensing actuator, the other end is fixedly provided with a valve plate, and a valve seat is fixedly provided in the valve body at a position corresponding to the valve plate.

[0013] The beneficial effects of this invention are: the purely mechanical temperature compensation mechanism, consisting of a temperature bulb, a compensation adjustment component, and a compensation piston, can respond in real time to changes in the sealing oil temperature, dynamically adjust the spring preload, and offset the effective pressure difference deviation caused by changes in sealing oil viscosity and system flow resistance due to oil temperature, ensuring that the oil-hydrogen pressure difference remains stable within the design allowable range and avoiding safety hazards such as hydrogen leakage and sealing oil entering the generator. Attached Figure Description

[0014] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of an oil-hydrogen differential pressure valve with temperature compensation according to the present invention.

[0016] Figure 2 This is a cross-sectional view of an oil-hydrogen differential pressure valve with temperature compensation according to the present invention.

[0017] Figure 3 This is a schematic diagram of the adjusting nut of an oil-hydrogen differential pressure valve with temperature compensation according to the present invention.

[0018] Figure 4 This is a schematic diagram of the push rod structure of an oil-hydrogen differential pressure valve with temperature compensation according to the present invention.

[0019] The labels in the diagram represent: 1. Valve assembly; 2. Actuating chamber; 3. Differential pressure sensing actuator; 4. First chamber; 5. Second chamber; 6. Spring box; 7. Spring; 8. Push rod; 9. Adjusting nut; 10. Compensating piston; 11. Compensating adjustment assembly; 12. Connecting pipe; 13. Temperature bulb; 14. Cylinder body; 15. Adjusting chamber; 16. Adjusting piston; 17. Handwheel; 18. Countersunk hole; 19. Extension; 20. Limiting groove; 21. Snap ring; 22. Thrust bearing; 23. Compression nut; 24. Threaded section; 25. Smooth rod section; 26. Sealing ring; 27. Anti-rotation retaining part; 28. Spring seat; 29. ​​Center; 30. Valve body; 31. Valve stem; 32. Valve plate; 33. Valve seat. Detailed Implementation

[0020] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0022] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0023] See Figures 1 to 4As shown, the structure of the present invention is as follows: an oil-hydrogen differential pressure valve with temperature compensation, including a valve assembly 1, an actuation chamber 2 on the valve assembly 1, the actuation chamber 2 being divided into a first chamber 4 and a second chamber 5 by a differential pressure sensing actuator 3, the differential pressure sensing actuator 3 being drively connected to the valve assembly 1; a spring box 6 is fixedly connected to the side of the actuation chamber 2 away from the valve assembly 1, the spring box 6 containing a spring 7 that abuts against the differential pressure sensing actuator 3, a push rod 8 slidingly passing through the top of the spring box 6, an adjusting nut 9 threadedly connected to the push rod 8, the adjusting nut 9 being rotatably engaged with the spring box 6; the top A compensating piston 10 is movably mounted inside the push rod 8. The piston rod of the compensating piston 10 abuts against the end of the spring 7 away from the differential pressure sensing actuator 3. A compensating adjustment component 11 is mounted on the end of the push rod 8 away from the spring box 6. The compensating adjustment component 11 is sealed to a temperature sensor 13 for sensing oil temperature via a connecting pipe 12. Specifically, the valve assembly 1, as the flow regulation actuator of the valve, forms a transmission cooperation with the differential pressure sensing actuator 3. It can directly respond to changes in the differential pressure signal to adjust the valve opening, thereby controlling the flow rate and output pressure of the sealing oil and realizing closed-loop regulation of the oil-hydrogen pressure difference. The actuator 2 is divided into a first chamber 4 and a second chamber 5 by the differential pressure sensing actuator 3. These chambers are used to receive the detection signals of the sealing oil pressure and hydrogen pressure, respectively. This allows the differential pressure sensing actuator 3 to directly sense the actual pressure difference between the two media, providing a direct drive signal for the valve's adjustment action. When the actual pressure difference deviates from the set value, the differential pressure sensing actuator 3 will generate an axial displacement corresponding to the pressure difference deviation, synchronously driving the valve assembly 1 to correct the sealing oil pressure and quickly return the oil-hydrogen pressure difference to the set range. The spring 7 inside the spring box 6 provides a stable preload force for the differential pressure sensing actuator 3. This preload force balances the force of the oil-hydrogen differential pressure. The preload of the spring 7 directly determines the reference setting value of the oil-hydrogen differential pressure, providing a reference elastic support for the differential pressure adjustment of the valve. The threaded transmission structure formed by the push rod 8 and the adjusting nut 9 converts the rotational motion of the adjusting nut 9 into the axial linear displacement of the push rod 8. By adjusting the axial position of the push rod 8, the preload of the spring 7 can be changed, achieving precise adjustment of the reference setting value of the oil-hydrogen differential pressure and adapting to the differential pressure control requirements under different operating conditions. The compensating piston 10, which is movable inside the push rod 8, can adjust the actual preload force of the spring 7 by superimposing its own axial displacement, providing adjustable stroke support for temperature compensation and realizing dynamic fine-tuning of the differential pressure setting value.The compensation and adjustment component 11 forms a closed pressure transmission system with the temperature bulb 13 through the connecting pipe 12. The temperature bulb 13 can directly sense the working oil temperature of the sealing oil. The temperature sensing medium filled inside it will generate corresponding volume and saturation pressure changes with the oil temperature. This pressure change is transmitted to the compensation and adjustment component 11 in real time through the connecting pipe 12, thereby driving the compensation piston 10 to generate corresponding axial displacement, and adjusting the preload of the spring 7 in real time. This offsets the oil-hydrogen pressure difference deviation caused by the change in sealing oil viscosity and system flow resistance due to the change in oil temperature. It solves the industry pain points of excessively high oil viscosity leading to excessive pressure difference and large amount of sealing oil entering the generator under low temperature conditions, and insufficient pressure difference and hydrogen leakage under high temperature conditions due to excessively low oil viscosity.

[0024] like Figure 2 As shown, the compensation adjustment assembly 11 includes a cylinder body 14, an adjustment chamber 15 on one side of the cylinder body 14, an adjustment piston 16 inside the adjustment chamber 15, and a piston rod of the adjustment piston 16 threadedly connected to the cylinder body 14. A handwheel 17 is provided at the end of the piston rod of the adjustment piston 16 away from the adjustment chamber 15. Specifically, the adjustment chamber 15 on the cylinder body 14, together with the connecting pipe 12 and the temperature bulb 13, constitutes a sealed pressure-sensing chamber. The adjustment piston 16 can move freely axially within the adjustment chamber 15. By rotating the handwheel 17, the piston rod of the adjustment piston 16 can be driven to rotate, and the adjustment piston 16 is driven to move axially through the threaded transmission, thereby adjusting the initial volume and reference pressure of the sealed pressure-sensing chamber, realizing zero-point calibration of the temperature compensation system, eliminating the zero-point offset problem caused by the filling deviation of the temperature-sensing medium and the volume error of the system processing and assembly; at the same time, the initial preload of the compensation system can be manually adjusted according to the temperature viscosity characteristics of different grades of sealing oil, matching the temperature compensation requirements of different units and different working conditions, and greatly improving the valve's working condition adaptability and temperature compensation accuracy.

[0025] like Figure 2 , Figure 3As shown, the top of the spring box 6 has a countersunk hole 18 for installing the adjusting nut 9. The bottom of the adjusting nut 9 has an extension 19 extending into the countersunk hole 18. A limiting groove 20 is formed on the outer periphery of the extension 19. A retaining spring 21 is provided in the limiting groove 20. Thrust bearings 22 are provided on both sides of the retaining spring 21. A clamping nut 23 that abuts against the thrust bearing 22 is threaded into the countersunk hole 18. Specifically, the extension 19 of the adjusting nut 9 is installed in the countersunk hole 18 of the spring box 6. The inner diameter of the extension 19 is larger than the outer diameter of the push rod 8. The retaining spring 21 and the limiting groove... The 20 mechanism enables the axial positioning of the adjusting nut 9, completely preventing axial movement of the adjusting nut 9 during adjustment and operation, and ensuring the accuracy of the displacement adjustment of the push rod 8. The thrust bearings 22 on both sides of the limiting groove 20 can convert the sliding friction of the adjusting nut 9 during rotation into rolling friction, greatly reducing the resistance of the adjustment operation, while completely isolating the influence of axial load on the rotation adjustment, ensuring the smoothness and accuracy of the differential pressure setting adjustment process. The clamping nut 23 clamps the thrust bearing 22 through threaded engagement, realizing the axial locking of the entire installation structure.

[0026] like Figure 4 As shown, the push rod 8 includes a threaded section 24 and a smooth section 25. The threaded section 24 is threadedly engaged with the adjusting nut 9, and the smooth section 25 slides through the top of the spring box 6. A sealing ring 26 is provided between the smooth section 25 and the spring box 6. Specifically, the threaded section 24 and the adjusting nut 9 form a precise threaded transmission engagement, which can accurately convert the rotational motion of the adjusting nut 9 into the axial linear motion of the push rod 8, realizing precise fine-tuning of the preload of the spring 7. The smooth section 25 and the sliding hole on the top of the spring box 6 form a precise sliding guide engagement, providing stable radial limit and guidance for the axial displacement of the push rod 8, avoiding radial wobble of the push rod 8 during adjustment and operation, and ensuring transmission accuracy and smooth operation. The sealing ring 26 provided between the smooth section 25 and the spring box 6 can reliably isolate and seal the inner cavity of the spring box 6 from the external environment, preventing internal media leakage, and at the same time preventing external dust and moisture from entering the spring box 6, causing the spring 7 to rust and jam, ensuring the long-term operational reliability and adjustment accuracy of the valve.

[0027] like Figure 4 As shown, a hollow anti-rotation retaining part 27 is integrally formed at one end of the push rod 8 near the threaded section 24. Specifically, the hollow anti-rotation retaining part 27 integrally formed at the end of the push rod 8 can form a stable retaining engagement with tools such as wrenches. During the process of rotating the adjusting nut 9 to adjust the axial position of the push rod 8, the anti-rotation retaining part 27 restricts the circumferential rotation of the push rod 8, completely avoiding the problem of the push rod 8 rotating synchronously with the adjusting nut 9, and ensuring that the rotational motion of the adjusting nut 9 can be completely converted into the axial linear displacement of the push rod 8.

[0028] like Figure 1 , Figure 4 As shown, the end of the spring 7 furthest from the differential pressure sensing actuator 3 is provided with a spring seat 28, and the piston rod end of the compensation piston 10 is provided with a tip 29 that abuts against the spring seat 28. Specifically, the spring seat 28 is fully fitted with the end of the spring 7, which can evenly distribute the pushing force of the compensation piston 10 to the entire end face of the spring 7, avoiding uneven wear and skewing of the end of the spring 7 due to local force, and ensuring the smoothness and uniformity of the extension and retraction of the spring 7. The tip 29 at the end of the piston rod of the compensation piston 10 abuts against the spring seat 28, which can automatically compensate for the coaxiality deviation between the compensation piston 10 and the spring seat 28 through small-area contact cooperation, completely eliminating the problem of jamming of the compensation piston 10 and loss of compensation force transmission caused by part processing and assembly errors. This ensures that during the temperature compensation process, the axial displacement of the compensation piston 10 can be accurately and losslessly converted into the adjustment of the preload of the spring 7, ensuring the response speed and control accuracy of temperature compensation, and can also limit the movement of the compensation piston 10.

[0029] like Figure 1 As shown, valve assembly 1 includes a valve body 30, within which a valve stem 31 is movably inserted. One end of the valve stem 31 is connected to a differential pressure sensing actuator 3, and the other end is fixedly fitted with a valve plate 32. A valve seat 33 is fixedly fitted within the valve body 30 at a position corresponding to the valve plate 32. Specifically, the flow channel within the valve body 30 provides a stable flow path for the sealing oil. The valve seat 33 and the valve plate 32 cooperate to form a controllable sealing pair. By adjusting the axial clearance between the valve plate 32 and the valve seat 33, the flow cross-sectional area of ​​the valve can be changed, thereby precisely controlling the flow rate and outlet pressure of the sealing oil. As a force transmission element, 31 can accurately transmit the axial displacement of the differential pressure sensing actuator 3 to the valve plate 32 without loss, ensuring that the opening of the valve plate 32 and the displacement of the differential pressure sensing actuator 3 form a linear correspondence, thus guaranteeing the linearity and response speed of differential pressure regulation. When the oil-hydrogen differential pressure deviates from the set value, the differential pressure sensing actuator 3 drives the valve stem 31 to move axially, synchronously driving the valve plate 32 to move closer to or away from the valve seat 33, adjusting the valve opening in real time, quickly correcting the output pressure of the sealing oil, and making the oil-hydrogen differential pressure return to the set range quickly, thus achieving closed-loop precise control of the oil-hydrogen differential pressure.

[0030] In practical use, under normal and stable operating conditions, the oil-hydrogen pressure difference is within the set range. The pressure difference force on both sides of the pressure difference sensing actuator 3 is balanced with the preload force of the spring 7, and the valve assembly 1 maintains a stable valve opening, keeping the sealing oil pressure stable. When the hydrogen pressure in the generator or the sealing oil supply pressure fluctuates, causing the actual oil-hydrogen pressure difference to deviate from the set value, the pressure difference sensing actuator 3 generates axial displacement under the drive of the pressure difference on both sides, synchronously driving the valve assembly 1 to adjust the valve opening, correcting the output pressure of the sealing oil, and making the oil-hydrogen pressure difference quickly return to the set range. When the working oil temperature of the sealing oil changes, the temperature sensor 13 senses the oil temperature change in real time and converts it into a corresponding pressure signal, which is transmitted to the compensation adjustment assembly 11 through the connecting pipe 12, driving the compensation piston 10 to generate axial displacement, dynamically fine-tuning the preload force of the spring 7, and performing real-time temperature compensation for the pressure difference set value, eliminating the influence of oil temperature changes on the pressure difference control accuracy, and ensuring that the valve can achieve stable and accurate control of the oil-hydrogen pressure difference within the entire oil temperature range.

[0031] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the nature and scope of the present invention. Various modifications made to the above embodiments by those skilled in the art after reading this specification are all within the scope of protection of the present invention.

Claims

1. An oil-hydrogen differential pressure valve with temperature compensation, characterized in that: The device includes a valve assembly (1), which has an actuation chamber (2). The actuation chamber (2) is divided into a first chamber (4) and a second chamber (5) by a differential pressure sensing actuator (3). The differential pressure sensing actuator (3) is connected to the valve assembly (1) in a transmission manner. A spring box (6) is fixedly connected to the side of the actuation chamber (2) away from the valve assembly (1). The spring box (6) has a spring (7) that abuts against the differential pressure sensing actuator (3). A push rod (8) is slidably inserted through the top of the spring box (6). An adjusting nut (9) is threaded onto the push rod (8), and the adjusting nut (9) is rotatably engaged with the spring box (6). A compensation piston (10) is movably provided inside the push rod (8), and the piston rod of the compensation piston (10) abuts against the end of the spring (7) away from the differential pressure sensing actuator (3). A compensation adjustment assembly (11) is provided at the end of the push rod (8) away from the spring box (6), and the compensation adjustment assembly (11) is sealed to a temperature sensor (13) for sensing oil temperature through a connecting pipe (12).

2. The oil-hydrogen differential pressure valve with temperature compensation according to claim 1, characterized in that: The compensation adjustment assembly (11) includes a cylinder (14), an adjustment chamber (15) is provided on one side of the cylinder (14), an adjustment piston (16) is provided in the adjustment chamber (15), the piston rod of the adjustment piston (16) is threadedly connected to the cylinder (14), and a handwheel (17) is provided at the end of the piston rod of the adjustment piston (16) away from the adjustment chamber (15).

3. The oil-hydrogen differential pressure valve with temperature compensation according to claim 1, characterized in that: The top of the spring box (6) is provided with a countersunk hole (18) for installing an adjusting nut (9). The bottom of the adjusting nut (9) is provided with an extension (19) extending into the countersunk hole (18). A limiting groove (20) is provided on the outer periphery of the extension (19). A retaining ring (21) is provided in the limiting groove (20). Thrust bearings (22) are provided on both sides of the retaining ring (21). A clamping nut (23) that abuts against the thrust bearing (22) is threaded into the countersunk hole (18).

4. The oil-hydrogen differential pressure valve with temperature compensation according to claim 1, characterized in that: The push rod (8) includes a threaded section (24) and a smooth section (25). The threaded section (24) is threadedly engaged with the adjusting nut (9). The smooth section (25) slides through the top of the spring box (6), and a sealing ring (26) is provided between the smooth section (25) and the spring box (6).

5. The oil-hydrogen differential pressure valve with temperature compensation according to claim 4, characterized in that: The push rod (8) has a hollow anti-rotation holding part (27) integrally formed at one end near the threaded section (24).

6. The oil-hydrogen differential pressure valve with temperature compensation according to claim 1, characterized in that: The spring (7) has a spring seat (28) at one end away from the differential pressure sensing actuator (3), and the piston rod of the compensation piston (10) has a tip (29) that abuts against the spring seat (28).

7. The oil-hydrogen differential pressure valve with temperature compensation according to claim 1, characterized in that: The valve assembly (1) includes a valve body (30), a valve stem (31) is movably inserted inside the valve body (30), one end of the valve stem (31) is connected to the differential pressure sensing actuator (3), and the other end is fixedly provided with a valve plate (32). A valve seat (33) is fixedly provided inside the valve body (30) at the position corresponding to the valve plate (32).

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