A cryogenic pressure relief valve for offshore oil drilling

Abstract

This invention discloses a cryogenic pressure relief valve for offshore oil drilling, relating to the field of pressure relief valves. It includes a pressure relief valve body with a valve cover at its top. An inlet pipe is connected to the left side of the valve body, and an outlet pipe is connected to the right side. The valve body also has an internal cleaning structure. This invention utilizes a flow meter, motor, rotating rod, and pusher plate. The flow meter, connected to the inner wall of the pipe, detects the flow velocity of the oil. When the flow velocity significantly decreases, the cylinder inside the rotating rod is activated. The cylinder causes a locking block to extend and insert into a groove on the inner wall of the rotating sleeve, fixing the rotating sleeve to the rotating rod. This, in turn, fixes the pusher plate to the rotating rod. At this point, the motor can be controlled to rotate the output rotating rod, rotating sleeve, and pusher plate. When the two sets of pusher plates rotate rapidly, they push the oil to the right, increasing the oil flow velocity and resolving the oil blockage problem.

Description

Technical Field

[0001] This invention relates to the field of pressure relief valves, specifically a cryogenic pressure relief valve for offshore oil drilling. Background Technology

[0002] Offshore oil refers to oil distributed in the bedrock of the seabed. Offshore oil drilling is an exploration project conducted in the continental shelf area for the prospecting and exploration of seabed oil and natural gas. The drilling depth is generally several kilometers. The oil extracted during drilling is transported through pipelines. In order to ensure the smooth transportation of oil, pressure relief valves are generally installed on the pipelines. The pressure relief valve is composed of components such as a needle valve, pressure gauge, main valve, pilot valve and connecting pipe. It is a type of hydraulic control valve. The main valve is divided into upper and lower parts by a diaphragm. The lower chamber of the diaphragm is the water flow channel, and the upper chamber is the control chamber, which controls the opening and closing of the main valve disc. The pilot valve itself is a pressure relief valve. It also has a control chamber and a water flow channel. The opening and closing of the valve disc is controlled by the control chamber. The needle valve is a throttle valve, which controls the flow rate of water in the connecting pipe.

[0003] Existing pressure relief valves used in offshore oil drilling have connecting pipes on both sides. Due to the viscous nature of oil, these pipes are prone to blockage. The blockages cannot be dealt with in a timely manner, leading to the stagnation of oil transportation. Therefore, there is an urgent need for a cryogenic pressure relief valve for offshore oil drilling. Summary of the Invention

[0004] The purpose of this invention is to address the problems of existing pressure relief valves used in offshore oil drilling, which have connecting pipes on both sides. Due to the viscous nature of oil, these pipes are prone to blockage, leading to stagnation in oil transportation. Furthermore, after oil transportation, a large amount of oil adheres to the inner wall of the pressure relief valve, and due to temperature variations, the oil dries and hardens within the valve, making cleaning impossible. Additionally, the pressure of the pilot valve needs to be adjusted via a threaded rod, but the threaded rod is exposed to air and easily becomes damp and rusted, affecting its usability. Therefore, this invention provides a cryogenic pressure relief valve for offshore oil drilling.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a cryogenic pressure relief valve for offshore oil drilling, comprising a pressure relief valve body, a valve cover at the top of the pressure relief valve body, an inlet pipe connected to the left side of the pressure relief valve body, an outlet pipe connected to the right side of the pressure relief valve body, a cleaning structure inside the pressure relief valve body, a valve seat on the inner wall of the pressure relief valve body, a pilot valve housing at the top of the valve cover, a pushing structure on the left side of the inlet pipe, and two... A copper tube is provided on the side, and a needle valve is installed on the copper tube. A pressure gauge is installed above the needle valve. A main valve core is engaged inside the valve seat. A valve stem is fixed inside the main valve core, and a main valve diaphragm is provided above the main valve core. A threaded rod is provided inside the pilot valve housing, and a protective structure is provided outside the pilot valve housing. A nut is sleeved on the outer wall of the threaded rod, and a spring is connected to the bottom end of the threaded rod. A pilot valve core is provided at the bottom end of the spring, and a pilot valve diaphragm is provided outside the pilot valve core.

[0006] The pushing structure includes a connecting pipe with flanges at both ends. A flow meter is installed on the inner wall of the connecting pipe, and a motor is installed on the outer side of the connecting pipe. A rotating rod is installed at the output end of the motor. A bearing is installed on the outer wall of the rotating rod, and a rotating sleeve is installed on the outer side of the rotating rod. A cylinder is installed inside the rotating rod, and a locking block is installed at the output end of the cylinder. A locking groove is opened on the inner wall of the rotating sleeve, and a pushing plate is connected to the outer wall of the rotating sleeve.

[0007] The cleaning structure includes a first heating tube with a power base installed at its end. The bottom end of the pressure relief valve body is connected to a first discharge pipe. Vibration motors are installed on both sides of the first discharge pipe, and a sealing cap is provided at the end of the first discharge pipe. A second heating tube is provided above the first heating tube, and a second discharge pipe is provided at the bottom end of the water outlet pipe. A third heating tube is provided above the second heating tube, and a third discharge pipe is provided to the right of the third heating tube.

[0008] The protective structure includes a magnetic ring, a counterweight ring attached to the top of the magnetic ring, a folding cover connected to the top of the counterweight ring, a fixing plate at the top of the folding cover, and an anti-compression rod fixed to the inner wall of the fixing plate.

[0009] Preferably, the valve stem and valve cover are connected by a limiting mechanism, the main valve diaphragm is fixedly connected to the valve cover, the main valve core is engaged with the valve seat, and the pilot valve housing and valve cover are fixedly connected by a connecting sleeve.

[0010] Preferably, the connecting pipe and the inlet pipe are fixedly connected by a flange and bolts, and the flow meter is fixedly connected to the connecting pipe by a mounting base.

[0011] Preferably, there are two motors, and the two motors and the connecting pipe are fixedly installed by a mounting bracket, and the rotating sleeve and the rotating rod are rotatably connected by a bearing.

[0012] Preferably, the rotating sleeve and the rotating rod are engaged and fixed by a cylinder, a locking block and a push plate, and the locking block is engaged and connected to the locking slot.

[0013] Preferably, the ends of the first heating tube, the second heating tube, and the third heating tube are all equipped with power bases, and the ends of the first discharge tube, the second heating tube, and the third discharge tube are all fitted with sealing caps.

[0014] Preferably, there are two vibration motors, and the vibration motors are fixedly installed to the pressure relief valve body by bolts.

[0015] Preferably, the threaded rod is movably connected to the pilot valve housing and the nut by bolts, and the two ends of the spring are fixedly connected to the threaded rod and the pilot valve core, respectively.

[0016] Preferably, the fixing plate is magnetically fixed to the threaded rod, the folding cover is fixed to the valve housing by adsorption through a counterweight ring and a magnetic ring, and the number of anti-compression rods is four.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] First, this invention uses a flow meter, a motor, a rotating rod, and a pusher plate. The flow meter connected to the inner wall of the pipe detects the flow rate of the oil. When the flow rate decreases significantly, the cylinder inside the rotating rod is controlled to operate. The cylinder drives a locking block to extend and insert into a slot in the inner wall of the rotating sleeve, thus fixing the rotating sleeve to the rotating rod. This, in turn, fixes the pusher plate to the rotating rod. At this time, the motor can be controlled to operate, driving the rotating rod, rotating sleeve, and pusher plate at the output end to rotate. When the two sets of pusher plates rotate rapidly, the oil is pushed to the right, increasing the flow rate of the oil and solving the problem of oil blockage.

[0019] Secondly, this invention, by setting up a first heating tube, a second heating tube, a third heating tube, a first discharge pipe, a second discharge pipe, and a third discharge pipe, allows the pressure relief valve body to stop supplying oil. The first, second, and third heating tubes are then controlled to operate, with the power base providing power. Once operating, the first, second, and third heating tubes heat the lower, middle, and upper chambers of the pressure relief valve, respectively. After heating, the oil adhering to the lower, middle, and upper chambers begins to detach. Simultaneously, the vibration motor at the bottom of the pressure relief valve body operates, generating vibration force. This vibration force is transmitted to the pressure relief valve body, accelerating the detachment of oil from the lower, middle, and upper chambers. At this point, the sealing caps at the ends of the first, second, and third discharge pipes are unscrewed, allowing the detached oil to flow out through the first, second, and third discharge pipes, thus cleaning the interior of the pressure relief valve body.

[0020] Third, this invention, by setting up a folding cover, a fixing plate, a pressure-resistant rod, a magnetic ring, and a counterweight ring, first sets the main valve opening pressure. Loosening the nut and rotating the adjusting threaded rod clockwise causes it to move downwards, increasing the main valve opening pressure. Turning it counterclockwise causes the threaded rod to move upwards, closing the main valve and reducing the pressure. After adjustment, tightening the nut fixes the threaded rod. Then, the folding cover is placed on the outside of the pilot valve housing, with the fixing plate at the top of the folding cover magnetically fixed to the threaded rod. Simultaneously, four pressure-resistant rods at the bottom of the fixing plate are positioned on the outside of the pilot valve housing for protection. Then, the counterweight ring at the bottom of the folding cover moves downwards and is attracted and fixed to the magnetic ring on the outer wall of the pilot valve housing, thus fixing the folding cover to the outside of the pilot valve housing and providing waterproof protection for the pilot valve housing, threaded rod, and nut. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the front section structure of the present invention;

[0023] Figure 3 This is a schematic diagram of the push structure of the present invention;

[0024] Figure 4 This is a schematic diagram of the push plate of the present invention;

[0025] Figure 5 For the present invention Figure 4 Enlarged diagram of A in the middle;

[0026] Figure 6 This is a schematic diagram of the cleaning structure of the present invention;

[0027] Figure 7 This is a schematic diagram of the power supply base of the present invention;

[0028] Figure 8 This is a schematic diagram of the protective structure of the present invention;

[0029] Figure 9 This is a schematic diagram of the folding cover of the present invention.

[0030] In the diagram: 1. Pressure relief valve body; 2. Valve cover; 3. Valve stem; 4. Main valve diaphragm; 5. Main valve core; 6. Inlet pipe; 7. Outlet pipe; 8. Pushing structure; 801. Connecting pipe; 802. Flange; 803. Flow meter; 804. Motor; 805. Rotating rod; 806. Bearing; 807. Rotating sleeve; 808. Cylinder; 809. Locking block; 810. Locking groove; 811. Pushing plate; 9. Cleaning structure; 901. First heating element; 902. First discharge pipe; 903. Sealing cover; 904. Second heating element; 905, Second discharge pipe; 906, Third heating element; 907, Third discharge pipe; 908, Power supply base; 909, Vibration motor; 10, Valve seat; 11, Copper pipe; 12, Needle valve; 13, Pressure gauge; 14, Pilot valve housing; 15, Threaded rod; 16, Nut; 17, Spring; 18, Pilot valve core; 19, Pilot valve diaphragm; 20, Protective structure; 2001, Magnetic ring; 2002, Counterweight ring; 2003, Folding cover; 2004, Fixing plate; 2005, Pressure-resistant rod. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 scope of protection of the present invention.

[0032] Please see Figure 1-5A cryogenic pressure relief valve for offshore oil drilling includes a pressure relief valve body 1, a valve cover 2 at the top of the pressure relief valve body 1, an inlet pipe 6 connected to the left side of the pressure relief valve body 1, an outlet pipe 7 connected to the right side of the pressure relief valve body 1, a cleaning structure 9 inside the pressure relief valve body 1, a valve seat 10 on the inner wall of the pressure relief valve body 1, a pilot valve housing 14 at the top of the valve cover 2, a pushing structure 8 on the left side of the inlet pipe 6, copper pipes 11 on both sides of the pilot valve housing 14, needle valves 12 mounted on the copper pipes 11, a pressure gauge 13 mounted above the needle valves 12, a main valve core 5 engaged inside the valve seat 10, a valve stem 3 fixed inside the main valve core 5, and a main valve diaphragm 4 above the main valve core 5. A threaded rod 15 is provided on the side, and a protective structure 20 is provided on the outer side of the pilot valve housing 14. A nut 16 is sleeved on the outer wall of the threaded rod 15, and a spring 17 is connected to the bottom end of the threaded rod 15. A pilot valve core 18 is provided at the bottom end of the spring 17, and a pilot valve diaphragm 19 is provided on the outer side of the pilot valve core 18. The pushing structure 8 includes a connecting pipe 801, flanges 802 are provided at both ends of the connecting pipe 801, and a flow meter 803 is installed on the inner wall of the connecting pipe 801. A motor 804 is installed on the outer side of the connecting pipe 801, and a rotating rod 805 is provided at the output end of the motor 804. A bearing 806 is provided on the outer wall of the rotating rod 805, and a rotating sleeve 807 is provided on the outer side of the rotating rod 805. A cylinder 808 is installed inside the rotating rod 805. The output end is equipped with a locking block 809, the inner wall of the rotating sleeve 807 is provided with a locking groove 810, and the outer wall of the rotating sleeve 807 is connected with a pusher plate 811. The valve stem 3 and the valve cover 2 are connected by a limiting movement. The main valve diaphragm 4 is fixedly connected to the valve cover 2. The main valve core 5 is engaged with the valve seat 10. The pilot valve housing 14 and the valve cover 2 are fixedly connected by a connecting sleeve. The connecting pipe 801 and the inlet pipe 6 are fixedly connected by a flange 802 and bolts. The flow meter 803 is fixedly connected to the connecting pipe 801 by a mounting base. There are two motors 804. The two motors 804 and the connecting pipe 801 are fixedly installed by a mounting bracket. The rotating sleeve 807 and the rotating rod 805 are rotatably connected by a bearing 806. The rotating sleeve 807 and the rotating rod 805 are connected by a cylinder. 808, 809, and 811 are engaged and fixed. 809 engages with slot 810. Connecting pipe 801 is connected to inlet pipe 6 via flange 802. Oil flows through connecting pipe 801, driving the two sets of push plates 811 and rotating sleeve 807 to rotate, thus entering the pressure relief valve body 1. Flow meter 803 on the inner wall of connecting pipe 801 detects the flow rate of the oil. When the flow rate decreases significantly, it controls cylinder 808 inside rotating rod 805 to operate. After cylinder 808 operates, it drives the output end of block 809 to extend and insert into slot 810 on the inner wall of rotating sleeve 807, thus fixing rotating sleeve 807 and rotating rod 805, thereby fixing push plate 811 and rotating rod 805.At this point, motor 804 can be controlled to operate. The internal technology of motor 804 is existing technology. After motor 804 starts operating, it drives the rotating rod 805, rotating sleeve 807, and pusher plate 811 at the output end to rotate. When the two sets of pusher plates 811 rotate rapidly, they push the oil to the right, increasing the oil flow rate and resolving the oil blockage problem.

[0033] Please see Figure 6-7 A cryogenic pressure relief valve for offshore oil drilling, wherein the cleaning structure 9 includes a first heating tube 901, a power base 908 installed at the end of the first heating tube 901, a first discharge pipe 902 connected to the bottom end of the pressure relief valve body 1, vibration motors 909 installed on both sides of the first discharge pipe 902, and a sealing cap 903 provided at the end of the first discharge pipe 902; a second heating tube 904 is provided above the first heating tube 901, and a second discharge pipe 904 is provided at the bottom end of the water outlet pipe 7. A third heating pipe 906 is installed above the first heating pipe 901, the second heating pipe 904, and a third discharge pipe 907 is installed to the right of the third heating pipe 906. Power supply bases 908 are installed at the ends of the first heating pipe 901, the second heating pipe 904, and the third heating pipe 906. Sealing caps 903 are fitted onto the ends of the first discharge pipe 902, the second heating pipe 904, and the third discharge pipe 907. Two vibration motors 909 are used, and they are bolted to the pressure relief valve body 1. After the pressure relief valve body 1 stops supplying oil, it controls the operation of the first heating pipe 901, the second heating pipe 904, and the third heating pipe 906. The power supply base 908 provides power, and the first heating pipe 901, the second heating pipe 904, and the third heating pipe 906 heat the lower, middle, and upper chambers of the pressure relief valve, respectively. After heating, the oil adhering to the lower, middle, and upper chambers of the pressure relief valve begins to fall off. Furthermore, the vibration motor 909 at the bottom of the pressure relief valve body 1 operates, generating vibration force. The vibration force is transmitted to the pressure relief valve body 1, accelerating the shedding of oil from the lower, middle, and upper chambers of the pressure relief valve. At this time, the sealing caps 903 at the ends of the first discharge pipe 902, the second discharge pipe 905, and the third discharge pipe 907 are unscrewed, and the shed oil flows out through the first discharge pipe 902, the second discharge pipe 905, and the third discharge pipe 907 respectively, thus cleaning the interior of the pressure relief valve body 1.

[0034] Please see Figure 8-9A cryogenic pressure relief valve for offshore oil drilling, the protective structure 20 includes a magnetic ring 2001, a counterweight ring 2002 attached to the top of the magnetic ring 2001, a folding cover 2003 connected to the top of the counterweight ring 2002, a fixing plate 2004 at the top of the folding cover 2003, and pressure-resistant rods 2005 fixed to the inner wall of the fixing plate 2004. A threaded rod 15 is movably connected to the pilot valve housing 14 and the nut 16 by bolts. Two ends of a spring 17 are fixedly connected to the threaded rod 15 and the pilot valve core 18, respectively. The fixing plate 2004 is magnetically fixed to the threaded rod 15. The folding cover 2003 and the pilot valve housing 14 are attracted and fixed by the counterweight ring 2002 and the magnetic ring 2001. There are four pressure-resistant rods 2005. First, the main valve opening pressure is set, the nut 16 is loosened, and the valve is rotated clockwise. Adjust the threaded rod 15 downwards. When the threaded rod 15 moves downwards, the main valve opening pressure increases. Turning it counterclockwise moves the threaded rod 15 upwards, closing the main valve and reducing the pressure. After adjustment, tighten the nut 16 to fix the threaded rod 15. Then, put the folding cover 2003 on the outside of the pilot valve housing 14. The fixing plate 2004 at the top of the folding cover 2003 is magnetically fixed to the threaded rod 15. At the same time, the four anti-pressure rods 2005 at the bottom of the fixing plate 2004 are set on the outside of the pilot valve housing 14 to achieve a protective function. Then, the counterweight ring 2002 at the bottom of the folding cover 2003 moves downwards and is attracted and fixed to the magnetic ring 2001 on the outer wall of the pilot valve housing 14. This fixes the folding cover 2003 on the outside of the pilot valve housing 14, providing waterproof protection for the pilot valve housing 14, the threaded rod 15, and the nut 16.

[0035] Working Principle: When using this invention, first set the main valve opening pressure, loosen the nut 16, and rotate the adjusting threaded rod 15 clockwise. The threaded rod 15 moves downward, increasing the main valve opening pressure. Turning it counterclockwise moves the threaded rod 15 upward, closing the main valve and reducing the pressure. After adjustment, tighten the nut 16 to fix the threaded rod 15. Then, the folding cover 2003 is placed on the outside of the pilot valve housing 14, and the fixing plate 2004 at the top of the folding cover 2003 is magnetically fixed to the threaded rod 15. At the same time, the four anti-pressure rods 2005 at the bottom of the fixing plate 2004 are set on the outside of the pilot valve housing 14 to achieve a protective function. Then, the counterweight ring 2002 at the bottom of the folding cover 2003 moves downward and is attracted to the magnetic ring 2001 on the outer wall of the pilot valve housing 14. With the attachment fixed, the folding cover 2003 is fixed to the outside of the pilot valve housing 14, providing waterproof protection for the pilot valve housing 14, threaded rod 15, and nut 16. The connecting pipe 801 is connected to the water inlet pipe 6 through the flange 802. Oil flows through the connecting pipe 801, driving the two sets of push plates 811 and the rotating sleeve 807 to rotate, thus entering the pressure relief valve body 1. The flow meter 803 on the inner wall of the connecting pipe 801 detects the flow rate of the oil. When the flow rate decreases significantly, the cylinder 808 inside the rotating rod 805 is controlled to operate. After the cylinder 808 operates, it drives the output end locking block 809 to extend and insert into the locking groove 810 on the inner wall of the rotating sleeve 807, thus fixing the rotating sleeve 807 and the rotating rod 805, thereby making The push plate 811 is fixed to the rotating rod 805. At this time, the motor 804 can be controlled to run. The internal technology of the motor 804 is existing technology. After the motor 804 runs, it drives the rotating rod 805, rotating sleeve 807 and push plate 811 at the output end to rotate. When the two sets of push plates 811 rotate rapidly, they push the oil to the right, increase the oil flow rate and solve the oil blockage problem. When the pressure in the lower chamber of the main valve rises abnormally, the pressure in the upper chamber rises accordingly. At this time, the pressure in the upper chamber of the pilot valve remains unchanged. The lower chamber of the pilot valve core 18 is connected to the upper chamber of the main valve. As the pressure rises with the upper chamber of the main valve, the pilot valve core 18 and the pilot valve diaphragm 19 will move upward. At this time, the pilot valve opens. After the pilot valve opens, the oil in the upper chamber of the main valve will be discharged quickly, and the pressure in the upper chamber will drop rapidly. Similarly, the main valve... The pressure in the lower chamber of the main valve is significantly higher than that in the upper chamber of the main valve. The main valve opens and begins to discharge oil and relieve pressure. When the pressure in the pipeline before the valve drops to the set value, the pilot valve chamber gradually closes as the pressure above and below the pilot valve core 18 tends to balance. The pressure in the upper chamber of the main valve diaphragm 4 gradually increases. Since the area of ​​the main valve diaphragm 4 is larger than that of the main valve core 5, the main valve core 5 closes under the action of the pressure difference, and the main valve stops relieving pressure. After the pressure relief valve body 1 stops supplying oil, the first heating tube 901, the second heating tube 904, and the third heating tube 906 are controlled to operate. The power base 908 provides power to them. After the first heating tube 901, the second heating tube 904, and the third heating tube 906 operate, they heat the lower chamber, the middle chamber, and the upper chamber of the pressure relief valve, respectively. After heating and temperature rise...The oil adhering to the lower, middle, and upper chambers of the pressure relief valve begins to detach, and the vibration motor 909 at the bottom of the pressure relief valve body 1 operates, generating vibration force. This vibration force is transmitted to the pressure relief valve body 1, accelerating the detachment of oil from the lower, middle, and upper chambers. At this time, the sealing caps 903 at the ends of the first discharge pipe 902, the second discharge pipe 905, and the third discharge pipe 907 are unscrewed, and the detached oil flows out through the first discharge pipe 902, the second discharge pipe 905, and the third discharge pipe 907 respectively, thus cleaning the interior of the pressure relief valve body 1.

[0036] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A cryogenic pressure relief valve for offshore oil drilling, comprising a pressure relief valve body (1), characterized in that: The pressure relief valve body (1) is provided with a valve cover (2) at its top, and an inlet pipe (6) is connected to the left side of the pressure relief valve body (1). An outlet pipe (7) is connected to the right side of the pressure relief valve body (1). A cleaning structure (9) is provided inside the pressure relief valve body (1). A valve seat (10) is provided on the inner wall of the pressure relief valve body (1). A pilot valve housing (14) is provided at the top of the valve cover (2). A push structure (8) is provided on the left side of the inlet pipe (6). Copper pipes (11) are provided on both sides of the pilot valve housing (14). A needle valve (12) is installed on the copper pipe (11). The needle valve (12) has a... A pressure gauge (13) is installed on the valve seat (10). A main valve core (5) is engaged inside the valve seat (10). A valve stem (3) is fixed inside the main valve core (5). A main valve diaphragm (4) is provided above the main valve core (5). A threaded rod (15) is provided inside the pilot valve housing (14). A protective structure (20) is provided on the outside of the pilot valve housing (14). A nut (16) is sleeved on the outer wall of the threaded rod (15). A spring (17) is connected to the bottom end of the threaded rod (15). A pilot valve core (18) is provided at the bottom end of the spring (17). A pilot valve diaphragm (19) is provided on the outside of the pilot valve core (18). The pushing structure (8) includes a connecting pipe (801), flanges (802) are provided at both ends of the connecting pipe (801), and a flow meter (803) is installed on the inner wall of the connecting pipe (801). A motor (804) is installed on the outer side of the connecting pipe (801). A rotating rod (805) is provided at the output end of the motor (804). A bearing (806) is provided on the outer wall of the rotating rod (805), and a rotating sleeve (807) is provided on the outer side of the rotating rod (805). A cylinder (808) is installed inside the rotating rod (805). A locking block (809) is provided at the output end of the cylinder (808). A locking groove (810) is opened on the inner wall of the rotating sleeve (807), and a pushing plate (811) is connected to the outer wall of the rotating sleeve (807). The cleaning structure (9) includes a first heating tube (901), a power base (908) is installed at the end of the first heating tube (901), a first discharge pipe (902) is connected to the bottom end of the pressure relief valve body (1), a vibration motor (909) is installed on both sides of the first discharge pipe (902), and a sealing cap (903) is provided at the end of the first discharge pipe (902). A second heating tube (904) is provided above the first heating tube (901), a second discharge pipe (905) is provided at the bottom end of the water outlet pipe (7), a third heating tube (906) is provided above the second heating tube (904), and a third discharge pipe (907) is provided on the right side of the third heating tube (906). The protective structure (20) includes a magnetic ring (2001), a counterweight ring (2002) is attached to the top of the magnetic ring (2001), a folding cover (2003) is connected to the top of the counterweight ring (2002), a fixing plate (2004) is provided at the top of the folding cover (2003), and an anti-compression rod (2005) is fixed to the inner wall of the fixing plate (2004).

2. The cryogenic pressure relief valve for offshore oil drilling according to claim 1, characterized in that: The valve stem (3) is connected to the valve cover (2) by a limiting movement, the main valve diaphragm (4) is fixedly connected to the valve cover (2), the main valve core (5) is engaged with the valve seat (10), and the pilot valve housing (14) is fixedly connected to the valve cover (2) by a connecting sleeve.

3. A cryogenic pressure relief valve for offshore oil drilling according to claim 1, characterized in that: The connecting pipe (801) and the inlet pipe (6) are fixedly connected by a flange (802) and bolts, and the flow meter (803) is fixedly connected to the connecting pipe (801) by a mounting base.

4. A cryogenic pressure relief valve for offshore oil drilling according to claim 1, characterized in that: The number of motors (804) is two. The two motors (804) and the connecting pipe (801) are fixedly installed by the mounting bracket. The rotating sleeve (807) and the rotating rod (805) are rotatably connected by the bearing (806).

5. A cryogenic pressure relief valve for offshore oil drilling according to claim 1, characterized in that: The rotating sleeve (807) and the rotating rod (805) are engaged and fixed by a cylinder (808), a locking block (809) and a push plate (811), and the locking block (809) is engaged and connected with the locking groove (810).

6. A cryogenic pressure relief valve for offshore oil drilling according to claim 1, characterized in that: The ends of the first heating tube (901), the second heating tube (904) and the third heating tube (906) are all equipped with power bases (908), and the ends of the first discharge tube (902), the second heating tube (904) and the third discharge tube (907) are all fitted with sealing caps (903).

7. A cryogenic pressure relief valve for offshore oil drilling according to claim 1, characterized in that: The number of vibration motors (909) is two, and the vibration motors (909) are fixedly installed with the pressure relief valve body (1) by bolts.

8. A cryogenic pressure relief valve for offshore oil drilling according to claim 1, characterized in that: The threaded rod (15) is movably connected to the pilot valve housing (14) and the nut (16) by bolts, and the two ends of the spring (17) are fixedly connected to the threaded rod (15) and the pilot valve core (18) respectively.

9. A cryogenic pressure relief valve for offshore oil drilling according to claim 1, characterized in that: The fixing plate (2004) is magnetically fixed to the threaded rod (15), the folding cover (2003) is magnetically fixed to the valve housing (14) by the counterweight ring (2002) and the magnetic ring (2001), and there are four anti-compression rods (2005).

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