Liquefied natural gas (LNG) ultralow-temperature pipeline emergency separation joint device

Abstract

The invention discloses an emergency joint disengaging device for an LNG ultralow-temperature pipeline. The quick connecting device comprises two butterfly valve devices, a butterfly valve execution transmission mechanism, an emergency release device and a quick connecting device, the two butterfly valve devices are installed at the two ends of the emergency release device respectively, one butterfly valve device is connected with the tail end of an outer arm pipeline of the unloading arm of the LNG receiving station, the other butterfly valve device is connected with the quick connecting device, and the quick connecting device is arranged below the unloading arm body and is in butt joint with an LNG transport ship manifold. And a butterfly valve execution transmission mechanism is mounted on the butterfly valve device. The emergency release device keeps stable connection between the coastal unloading arm and the manifold under the condition of small pulling force or small displacement, the emergency release function is achieved under the condition of large pulling force or large displacement, the LNG unloading arm is rapidly separated from the deck and the ship side of the LNG transport ship through the emergency release device and the rapid connection device, and therefore the LNG transport ship is protected. Therefore, the safety of the unloading arm is ensured.

Description

Technical Field

[0001] The invention belongs to the field of gas transmission systems for offshore LNG loading and unloading operations, and in particular relates to an emergency disconnection joint device for an LNG ultra-low temperature pipeline. Background Art

[0002] With the continuous expansion of the scale of marine LNG application, in the production and transportation of marine LNG, the LNG ultra-low temperature flexible pipe emergency disconnection joint has gradually become one of the key core equipment of the marine LNG transmission system. In the process of loading and unloading operations between LNG carriers and coastal LNG receiving stations, the main focus of work is on the safety and efficiency of loading and unloading operations. Once the LNG carrier encounters sudden accidents such as typhoons and wind and wave currents at sea during loading and unloading operations with coastal LNG receiving stations, causing the carrier to drift away from the receiving station dock, the LNG carrier will pull the unloading arm, causing damage to the unloading arm and LNG leakage, and even causing the unloading arm to topple, causing immeasurable losses. At this time, the LNG carrier must be quickly separated from the unloading arm, otherwise the LNG with volatility, ultra-low temperature and flammable and explosive characteristics will cause frostbite, suffocation, and even fire and explosion accidents to the staff. It is usually chosen to install an emergency disconnection joint on the LNG unloading arm to protect the safety of LNG unloading and personal safety, and avoid environmental pollution and economic losses. Therefore, the emergency release device of the LNG loading and unloading operation system must have sufficient emergency capabilities.

[0003] LNG ultra-low temperature flexible pipe emergency release joint is mainly used in the outer arm of the unloading arm of the coastal LNG receiving station. Its main function is to ensure the safety of the entire loading and unloading operation system during the offshore LNG loading and unloading operation. When special circumstances such as offshore typhoons or wind and wave currents occur during the loading and unloading operation, the LNG transport ship and the LNG unloading arm can be quickly and urgently released. This protects the unloading safety and personal safety of the LNG receiving station, avoids environmental pollution and economic losses, and reduces the probability of accidents at the LNG receiving station. Therefore, the performance of the emergency release joint directly affects the reliable operation of the LNG transportation system.

[0004] In summary, the LNG ultra-low temperature flexible pipe emergency disconnect joint involves many links such as cryogenic material selection, molding and manufacturing, sealing, and test verification. The entire set of cryogenic flexible pipe emergency disconnect joints has a complex structure and high safety requirements. Therefore, there is an urgent need for a large-size, fast-disconnecting, and reliable-sealing LNG ultra-low temperature pipeline emergency disconnect joint device to provide a useful reference for the selection of relevant parameters of the actual offshore gas transmission system. The traditional LNG ultra-low temperature flexible pipe emergency disconnect joint requires the complicated operation of reconnecting the valves on both sides and the valve transmission mechanism, which cannot adapt to the changes in the loading and unloading conditions of LNG transport ships and the requirements for lightweight equipment, operational safety, and reliability. Summary of the invention

[0005] The purpose of the present invention is to provide an emergency disconnect joint device for LNG ultra-low temperature pipelines.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] An LNG ultra-low temperature pipeline emergency disconnection joint device comprises: two butterfly valve devices, a butterfly valve actuator transmission mechanism, an emergency release device and a quick connection device; the two butterfly valve devices are respectively installed at both ends of the emergency release device, one of the butterfly valve devices is connected to the end of the outer arm pipeline of the unloading arm of the LNG receiving station, and the other butterfly valve device is connected to the quick connection device, the quick connection device is below the unloading arm body and docked with the manifold of the LNG transport ship, the butterfly valve actuator transmission mechanism is installed on the butterfly valve device, the butterfly valve device is used to adjust the flow resistance of LNG liquid and quickly open and close the valve; the emergency release device maintains a stable connection between the coastal unloading arm and the manifold under small pulling force or small displacement conditions, realizes an emergency disconnection and release function under large pulling force or large displacement conditions, and through the emergency release device and the quick connection device, the LNG unloading arm is quickly disconnected from the deck and side of the LNG transport ship, thereby ensuring the safety of the unloading arm.

[0008] Furthermore, the emergency release device includes two valve bodies connected by a breaking bolt, a pin is installed at the center of the valve body, a plug is located at the end of the pin, the pin is threadedly connected to the plug, and a spring is sleeved at the center of the pin; an O-ring is embedded in the pin; the pin is used to achieve emergency disengagement, and the quick break function also serves as an auxiliary device to assist the butterfly valve in sealing to prevent LNG leakage and reduce environmental pollution.

[0009] Furthermore, the valve body is provided with a protective sleeve outside, and a protective interlayer is provided between the valve body and the protective sleeve.

[0010] Furthermore, the quick connection device includes an outer wall body, one end of which is equipped with a group of hydraulic cylinders and a group of claws arranged in a circle, the hydraulic cylinder is installed on a hydraulic cylinder support, the claw is tightly connected to one end of the claw connector, the outer side of the claw connector is provided with lateral support by a claw support member to prevent displacement; the other end of the claw connector is inserted into the head cylinder of the hydraulic cylinder, and a Gray sealing ring is put on the outer side of the other end of the head cylinder to prevent oil and gas leakage; a dust plug is put in the middle of the head cylinder and the end cylinder; the end cylinder is at the outermost side of the claw (44), and there is an exhaust valve on the side of the end cylinder.

[0011] Furthermore, the claw connecting member is a planar connecting rod mechanism, one end of the hydraulic cylinder base of the planar connecting rod mechanism is connected to the outer wall body, and one end of the piston rod of the hydraulic cylinder of the planar connecting rod mechanism is connected to the claw.

[0012] Furthermore, when the hydraulic oil is pushed toward the hydraulic cylinder of the quick-connect device, the piston in the hydraulic cylinder will move due to the oil pressure, and this movement is transmitted to the claw through the claw connector, so that the claw can open or close. By precisely controlling the flow and pressure of the hydraulic oil, the opening and closing speed of the claw and the clamping force can be precisely regulated.

[0013] Furthermore, the butterfly valve actuator transmission mechanism includes a cover plate, an electromagnet, a spring, a cylindrical gear and a rack are placed inside the cover plate, the electromagnet is against one end of the spring, the other end of the spring is connected to the side of the rack, and the rack is meshed with the cylindrical gear; the lower part of the cover plate is connected to the rotating shaft, a drip tray is mounted on the rotating shaft, packings are screwed into the water tray and the rotating shaft, and a sealing ring is placed on the packing; the butterfly valve actuator transmission mechanism is used to simultaneously drive the opening and closing of the double butterfly valves, to ensure the synchronization of opening and closing of the two butterfly valve devices when they are in operation, and to avoid interlocking operation failures and failures.

[0014] Furthermore, the butterfly valve device includes a butterfly valve body, which is connected to the end cover, the internal flange, and the external flange. A circular butterfly plate is provided in the cylindrical channel inside the butterfly valve body. The circular butterfly plate rotates around the rotating axis, and the rotation angle is between 0° and 90°. When it rotates to 90°, the butterfly valve is in a fully open state.

[0015] Furthermore, a graphite gasket and a sealing ring are provided between the butterfly valve and the emergency release device to prevent leakage of the medium due to failure of the structural seal between the valve body and the valve cover of the butterfly valve and the breakaway valve.

[0016] The beneficial effects of the present invention are:

[0017] In the process of LNG loading and unloading, if special circumstances such as offshore typhoons or wind and wave currents occur, when the valve body of the emergency release device is subjected to a tensile force reaching or exceeding the designed breaking force, the break valve will break at the shrinkage of the breaking bolt preset in the middle, and at the same time, the ejector pin will instantly seal the flow in the valve bodies at both ends, so that the LNG transport ship and the unloading arm can be urgently and quickly separated, and the sealing between the LNG transport ship manifold and the LNG unloading arm can be guaranteed.

[0018] The present invention adopts an emergency release device of a break valve structure, adopts a disengagement method in which the valve body is first broken and disengaged, and then an ejector pin in the valve body contacts the valve body to achieve automatic sealing, thereby maintaining a stable connection between the coastal unloading arm and the manifold under conditions of small pulling force or small displacement, and realizing an emergency disengagement and release function under conditions of large pulling force or large displacement, and through the emergency release device and the quick connection device, the LNG unloading arm is quickly disengaged from the deck and the side of the LNG transport ship, thereby ensuring the safety of the unloading arm. When it is restored to reuse, it only needs to replace the breaking bolts of the break valve to achieve reconnection of the entire device, which not only ensures rapid disengagement in an emergency situation, but also realizes rapid resumption of work after the emergency situation is relieved, and provides a reference basis for the design of large-diameter ultra-low temperature pipe structures that can adapt to -162℃.

[0019] The emergency release device of the present invention is an important facility to ensure the safe operation of the unloading arm. Researching a new type of emergency release device and studying existing hydraulic problems is conducive to improving the reliability of existing equipment and ensuring the safety of the entire hydraulic control system, effectively improving economic benefits and social value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Attached Figure 1 It is a structural schematic diagram of the present invention.

[0021] Attached Figure 2 It is a schematic structural diagram of the quick connection device of the present invention.

[0022] Attached Figure 3 It is a structural schematic diagram of the emergency release device of the present invention.

[0023] Attached Figure 4 It is a structural schematic diagram of a butterfly valve and a butterfly valve actuator of the present invention.

[0024] In the figure: 1. butterfly valve; 2. butterfly valve actuator; 3. emergency release device; 4. quick connection device; 5. flat washer 1; 6. composite bearing; 7. flat washer 2;

[0025] 31. Valve body; 32. Protective sleeve; 33. Breaking bolt; 34. Nut; 35. Screw plug; 36. Ejector pin; 37. Spring; 38. O-ring; 39. Protective interlayer;

[0026] 41. Hydraulic cylinder support; 42. Claw connector; 43. Claw support; 44. Claw; 45. Gley seal; 46. End cylinder; 47. Exhaust valve; 48. Dust plug; 49. Head cylinder;

[0027] 81. Rack; 82. Electromagnet; 83. Spring; 84. Cover plate; 85. Rotating shaft; 86. Inner flange; 87. End cover; 88. Outer flange; 89. Flat washer three; 90. Drip tray; 91. Packing; 92. Sealing retaining ring; 93. Cylindrical gear; 94. Circlip; 95. Butterfly plate. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings.

[0029] Embodiment 1:

[0030] According to an embodiment of the present invention, there is provided an LNG ultra-low temperature pipeline emergency disconnection joint device, as shown in the attached Figure 1 As shown, after being guided by the guide device for alignment and positioning, the hydraulic cylinder on the quick connection device starts to start operation, and the butterfly valve actuator 2 drives the rotating shaft 85 of the butterfly valve to drive the butterfly plate 95 to rotate 90°, closing the butterfly valves 1 on both sides to prevent LNG leakage after the emergency release device 3 is disconnected; finally, the breaking bolt 33 breaks under the action of external force, the entire LNG ultra-low temperature flexible pipe is separated from the emergency disconnection joint, and the butterfly valves 1 on both sides are separated under the action of external force, and the hydraulic cylinder drives the front end claw 44 to move to clamp the ship-side butterfly valve 1 of the emergency disconnection joint with the quick connection device 4, and finally achieve docking and locking.

[0031] This embodiment is based on the butterfly valve 1, the emergency release device 3, the quick connection device 4 and the butterfly valve actuator 2, and uses the emergency release device 3 (breakaway valve) as the main body of the emergency release device, and adopts the method of breaking the valve body 31 first, and then realizing the automatic sealing by contacting the valve body 31 with the ejector pin 56 in the valve body 31. It can realize the stable connection between the coastal discharge arm and the manifold under the condition of small pulling force or small displacement, and realize the emergency separation and release function under the condition of large pulling force or large displacement. After the emergency separation operation is completed, the butterfly valve on the LNG discharge arm side and half of the emergency release device are retracted to the coastal LNG receiving station with the movement of the outer arm of the discharge arm, while the butterfly valve on the LNG transport ship side and half of the emergency release device are moved away from the coastal receiving station with the movement of the transport ship manifold. The butterfly valves and breakaway valves on both sides are in the closed state at this time. After the emergency situation is handled, the breaking bolt 33 can be replaced again to realize the reconnection of the whole device, and the whole LNG ultra-low temperature flexible pipe emergency separation joint can be put into use again for LNG loading and unloading operations. Compared with the complicated operation of traditional LNG ultra-low temperature flexible pipe emergency disconnection joints that require reconnecting the valves on both sides and the valve transmission mechanism, it is simpler and faster. It not only ensures rapid disconnection in an emergency, but also realizes the rapid resumption of work after the emergency is lifted.

[0032] As attached Figure 2As shown, the quick connection device 4 includes an outer wall body, one end of which is equipped with a group of hydraulic cylinders and a group of claws arranged in a circle, the hydraulic cylinder is installed on a hydraulic cylinder support 41, the claw 44 is tightly connected to one end of the claw connector 42, and the outer side of the claw connector 42 is provided with lateral support by a claw support 43 to prevent displacement; the other end of the claw connector 42 is inserted into the head cylinder 49 of the hydraulic cylinder, and the outer side of the other end of the head cylinder 49 is covered with a Gley sealing ring 45 to prevent oil and gas leakage; a dust plug 48 is provided in the middle of the head cylinder 49 and the end cylinder 46; the end cylinder 46 is at the outermost side of the claw 44, and an exhaust valve 47 is provided on the side of the end cylinder 46.

[0033] Specifically, the claw connector 42 is a planar linkage mechanism, one end of a hydraulic cylinder base of the planar linkage mechanism is connected to the outer wall body, and one end of a piston rod of the hydraulic cylinder of the planar linkage mechanism is connected to the claw 44 .

[0034] When the hydraulic oil is pushed toward the hydraulic cylinder of the quick connection device 4, the piston in the hydraulic cylinder will move due to the oil pressure, and this movement is transmitted to the claw 44 through the claw connection piece, so that the claw 44 can open or close. By accurately controlling the flow and pressure of the hydraulic oil, the opening and closing speed and the clamping force of the claw 44 can be accurately regulated.

[0035] The hydraulic drive part provides operating power for the claw of the moving connection part of the device. In the planar connecting rod transmission mechanism of the transmission part, one end of the hydraulic cylinder base is connected to the quick connection device body, and one end of the piston rod of the hydraulic cylinder is connected to the claw of the quick connection device.

[0036] As attached Figure 3 As shown, the emergency release device 3 of this embodiment uses two actuators to control the two valves and the emergency release joint respectively. The butterfly valve 1 is driven to open and close simultaneously through the connecting rod mechanism driving device, and the other hydraulic cylinder push rod opens the emergency release interface to complete the separation of the double butterfly valves.

[0037] In this embodiment, the sealing between the rotating shaft 85 of the butterfly valve and the butterfly valve body 31 is added with an O-ring, and the rotating shaft 4 at the other end can be simplified to reduce the weight of the entire emergency release device. Under this structure, the structural design of the valve cover 8 can be removed, and the valve body 6 adopts an integral welding structure to increase the structural stability and avoid the leakage of the butterfly valve 15 caused by deformation between the valve cover 8 and the valve body 6 under ultra-low temperature conditions.

[0038] The emergency release device 3 of this embodiment is connected between the two butterfly valve 1 components as an emergency release device. When the valve body 31 is subjected to a tensile force that reaches or exceeds the designed breaking force, the emergency release device 3 will break at the constricted portion of the preset breaking bolt 33 in the middle, and at the same time, the ejector pin 36 will instantly block the internal flow of the valve bodies at both ends, so that the LNG transport ship can be quickly and urgently separated from the unloading arm, and the sealing between the LNG transport ship manifold and the LNG unloading arm can be guaranteed.

[0039] The emergency release device 3 of this embodiment is a symmetrical structure. The outermost protective sleeve 32 prevents the valve body 31 from being damaged. The breaking bolt 33 locks the valve bodies 31 on both sides through the nut 34. The spring 37 and the O-ring 38 are embedded inside the ejector pin 36. The outer side of the ejector pin 36 is limited by the wire plug 35. When the breaking bolt 33 is subjected to large external pressure and large displacement, the emergency release device is separated. When the hydraulic oil is pushed into the hydraulic cylinder, the piston in the hydraulic cylinder will move due to the oil pressure. This movement is transmitted to the claw 44 through the claw connection mechanism 42, so that the claw 44 can realize the opening or closing action. By accurately controlling the flow and pressure of the hydraulic oil, the opening and closing speed of the claw and the clamping force can be accurately regulated. The butterfly valve 1 is a valve that uses a circular butterfly plate 95 as an opening and closing member to open and close and regulate the flow of medium in a pipeline. In the cylindrical channel of the butterfly valve body, the break valve 14 rotates around the rotating shaft 85, and the rotation angle is between 0° and 90°. When it rotates to 90°, the butterfly valve is in a fully open state.

[0040] The sealing structure of this embodiment includes the sealing design of the butterfly valve 1 and the emergency release device 3. The sealing ring is installed in the sealing groove and is manufactured using an integrated design to prevent the structural sealing between the valve body and the valve cover of the butterfly valve and the breakaway valve from failing, resulting in leakage of the medium.

[0041] As attached Figure 4As shown, the butterfly valve actuator 2 of this embodiment includes a cover plate 84, wherein an electromagnet 82, a spring 83, a cylindrical gear 93, and a rack 81 are placed inside the cover plate 84, wherein the electromagnet 82 is against one end of the spring 83, and the other end of the spring 83 is connected to the side of the rack 81, and the rack 81 is meshed with the cylindrical gear 93; the lower part of the cover plate 84 is connected to the rotating shaft 85, and the rotating shaft 85 is covered with a drip tray 90, and a packing 91 is screwed into the water tray 90 and the rotating shaft 85, and a sealing retaining ring 92 is placed on the packing 91; the butterfly valve actuator 2 is used to simultaneously drive the opening and closing of the double butterfly valves, to ensure the synchronization of the opening and closing of the two butterfly valve devices 1 when they are in operation, and to avoid interlocking operation failure and failure. When the electromagnet coil is energized, the magnetic field generated will attract the armature (or valve core), thereby driving the mechanical parts (such as the valve stem) connected thereto to move, and realize the opening of the butterfly valve. When the solenoid coil is powered off, the magnetic field disappears, and the armature returns to its original position under the action of the spring force, thereby driving the butterfly valve to close. In the butterfly valve actuator, the magnetic field generated by the electromagnet directly controls the movement of the valve core, thereby realizing the valve switch. The electromagnet and the strong spring cooperate with the gear rack transmission mechanism as a driving device to simultaneously drive the opening and closing of the double butterfly valve. The action of the electromagnet is amplified by the gear rack transmission mechanism to provide sufficient torque to drive the rotating shaft of the butterfly valve to realize the opening and closing of the butterfly valve.

[0042] The emergency release device of this embodiment realizes the emergency release and disengagement of the two butterfly valves on the arm side and the ship side. The two butterfly valves are disengaged by following the movement of the LNG unloading arm and the LNG transport ship respectively. Secondly, the actuators of the valves on both sides close the two valves at the same time to prevent the flow of the transport medium in the pipeline, namely LNG, and complete the emergency disengagement of the LNG unloading arm and the LNG transport ship.

[0043] The 16-inch discharge arm emergency release device developed by the present invention provides a theoretical basis and reference value for the research and development design of larger equipment (such as a 20-inch discharge arm emergency release device). Emergency release is performed by using a breakaway valve to break the bolt. The analysis results show that its structural design and material selection meet the overall device design and functional requirements, can realize the emergency release function, and ensure the rationality and reliability of the design.

[0044] The structural layout of this embodiment is the unloading arm of the coastal LNG receiving station - butterfly valve on the arm side - emergency release device (i.e. break valve) - butterfly valve on the ship side - quick connection device - LNG transport ship manifold. The butterfly valve actuator is located at the upper end of the valve stem of the two butterfly valves, which is mainly composed of a driving device of an electromagnet and a strong spring in conjunction with a gear rack transmission mechanism; the emergency release device adopts the design of a break valve; the quick connection device is mainly composed of an outer wall body, 10 hydraulic cylinders and 10 matching claws. The butterfly valves on both sides are connected to the emergency release device, i.e. the break valve, through threads, while the butterfly valve on the ship side and the quick connection device are connected and clamped by the hydraulic cylinder on the quick connection device pushing the claws. During the LNG loading and unloading operation, if there are special circumstances such as offshore typhoons or wind and wave currents, when the valve body of the breakaway valve is subjected to a tensile force that reaches or exceeds the designed breaking force, the breakaway valve will break at the shrinkage of the preset breaking bolt in the middle, and at the same time, the ejector pin will instantly block the flow in the valve bodies at both ends, enabling the LNG carrier to be quickly and urgently separated from the unloading arm, and ensuring the sealing between the LNG carrier manifold and the LNG unloading arm.

[0045] This embodiment uses an emergency release device of a break valve structure, adopts a disengagement method in which the valve body is first broken and disengaged, and then the ejector pin in the valve body contacts the valve body to achieve automatic sealing, thereby maintaining a stable connection between the coastal unloading arm and the manifold under conditions of small pulling force or small displacement, and realizing an emergency disengagement and release function under conditions of large pulling force or large displacement, and through the emergency release device and the quick connection device, the LNG unloading arm is quickly disengaged from the deck and the side of the LNG transport ship, thereby ensuring the safety of the unloading arm. When it is restored to use, it is only necessary to replace the breaking bolts of the break valve to achieve reconnection of the entire device, which not only ensures rapid disengagement in an emergency situation, but also realizes rapid resumption of work after the emergency situation is lifted, and provides a reference for the design of large-diameter ultra-low temperature pipe structures that can adapt to -162°C.

[0046] Embodiment 2:

[0047] According to the LNG ultra-low temperature pipeline emergency disconnection joint device described in Example 1, its emergency disconnection process is as follows:

[0048] The outer arm of the LNG unloading arm is usually installed at a coastal LNG receiving station. When the LNG unloading arm is normally performing LNG loading and unloading operations, the two butterfly valves 1 are in a normally open state. When the coastal LNG receiving station is loading and unloading LNG, the LNG unloading arm is connected to the manifold of the LNG transport ship. When emergency weather conditions such as wind, waves, and offshore typhoons occur during the loading and unloading operation and the LNG unloading arm needs to be urgently disconnected from the LNG transport ship, before the emergency release device 3, i.e., the breaking bolt 33 of the break valve, undergoes a large deformation and breaks under the action of external force, the staff on the LNG transport ship needs to first shut down the unloading pump on the LNG transport ship to prevent the butterfly valve plate from being damaged by water hammer caused by the water hammer effect when the two butterfly valves are closed; secondly, the butterfly valve actuator 2 drives the butterfly valve stem to drive the valve plate to rotate 90°, closing the butterfly valves on both sides to prevent LNG leakage after the emergency release device is disconnected; finally, when the emergency release device 3, i.e., the breaking bolt of the break valve, breaks under the action of external force, the entire LNG ultra-low temperature flexible pipe is disconnected from the emergency joint, and the butterfly valves 1 on both sides are separated under the action of external force. At this time, the butterfly valve on the LNG transport ship side moves away from the coastal LNG receiving station along with the manifold of the transport ship, while the butterfly valve on the LNG unloading arm side of the coastal LNG receiving station rises along with the outer arm of the unloading arm, and the emergency disengagement operation is completed.

[0049] Offshore LNG loading and unloading operation workflow:

[0050] When the LNG carrier enters the coastal LNG receiving station and approaches the LNG unloading arm, the LNG carrier manifold and the LNG unloading arm outer arm hose of the coastal LNG receiving station are connected outboard and aligned and positioned by the guide device, and the LNG carrier manifold and the LNG unloading arm of the coastal LNG receiving station are docked and locked by the quick connection device. During the unloading operation, once an emergency such as a typhoon and wind and wave current causes the LNG carrier to drift away from the coastal LNG receiving station, and the tension between the LNG carrier manifold and the LNG unloading arm outer arm hose of the coastal LNG receiving station exceeds 10KN, the emergency release device, i.e., the breakaway valve, breaks off at the preset breakaway bolt reduction in the middle, breaks off and separates the LNG carrier manifold and the LNG unloading arm outer arm hose of the coastal LNG receiving station, and instantly closes the valves at both ends to prevent the internal transport medium from spilling and leaking, so that the LNG carrier can be quickly and urgently separated from the unloading arm and the sealing of the LNG carrier manifold and the LNG unloading arm on both sides can be ensured. After the emergency release device 3, i.e. the breakaway valve, is disconnected by tension, the butterfly valve transmission mechanism 2 is actuated to close the butterfly valve on the LNG unloading arm side and the butterfly valve on the LNG transport ship side respectively, and the butterfly valve plate and the valve body form a secondary seal to prevent the internal transport medium from leaking out.

[0051] Subsequently, the butterfly valve and half of the breakaway valve on the LNG unloading arm side are retracted to the coastal LNG receiving station as the outer arm of the unloading arm moves, while the butterfly valve and half of the breakaway valve on the LNG carrier side are moved away from the coastal LNG receiving station as the manifold of the LNG carrier moves, achieving rapid disengagement in an emergency.

[0052] When the emergency is over and the normal LNG loading and unloading operations need to be resumed, the LNG ultra-low temperature flexible pipe must be disconnected from the joint for emergency reconnection so that it can be used again. On-site operators only need to replace the emergency release device, that is, the breaking bolt of the breakaway valve, to reconnect the entire device and put it into use again.

[0053] Compared with the complicated operation of reconnecting the valves on both sides and the valve transmission mechanism of the traditional LNG ultra-low temperature flexible pipe emergency disconnection joint, the present invention is simpler and faster, not only ensuring the rapid disconnection in an emergency situation, but also realizing the rapid resumption of work after the emergency situation is lifted.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An LNG ultra-low temperature pipeline emergency disconnection joint device, characterized in that: include: Two butterfly valve devices (1), a butterfly valve actuator (2), an emergency release device (3) and a quick connection device (4); The two butterfly valve devices (1) are respectively installed at both ends of the emergency release device (3), one of the butterfly valve devices (1) is connected to the end of the outer arm pipeline of the unloading arm of the LNG receiving station, and the other butterfly valve device (1) is connected to the quick connection device (4), the quick connection device (4) is below the unloading arm body and docked with the manifold of the LNG transport ship, the butterfly valve device (1) is installed with the butterfly valve actuator (2), the butterfly valve device (1) is used to adjust the flow resistance of LNG liquid and quickly open and close the valve; the emergency release device (3) maintains a stable connection between the coastal unloading arm and the manifold under the condition of small pulling force or small displacement, and realizes an emergency release function under the condition of large pulling force or large displacement, and through the emergency release device (3) and the quick connection device (4), the LNG unloading arm is quickly separated from the deck and the side of the LNG transport ship, thereby ensuring the safety of the unloading arm.

2. The LNG ultra-low temperature pipeline emergency disconnect joint device according to claim 1 is characterized in that: The emergency release device (3) comprises two valve bodies (31) connected by a breaking bolt (33), a pin (36) is installed at the center of the valve body (31), a screw plug (35) is located at the end of the pin (36), the pin (36) is threadedly connected to the screw plug (35), and a spring (37) is sleeved at the center of the pin; an O-ring (38) is embedded in the pin (36); the pin (36) is used to achieve emergency separation, and the quick breaking function also serves as an auxiliary device to assist the butterfly valve in sealing to prevent LNG leakage and reduce environmental pollution.

3. The LNG ultra-low temperature pipeline emergency disconnect joint device according to claim 2 is characterized in that: The valve body (31) has a protective sleeve (32) on the outside, and a protective interlayer (39) is provided between the valve body (31) and the protective sleeve (32).

4. The LNG ultra-low temperature pipeline emergency disconnect joint device according to claim 1, characterized in that: The quick connection device (4) comprises an outer wall body, one end of which is provided with a group of hydraulic cylinders and a group of claws arranged in a circumferential manner, the hydraulic cylinder being installed on a hydraulic cylinder support (41), the claw (44) being tightly connected to one end of a claw connector (42), the outer side of the claw connector (42) being provided with lateral support by a claw support member (43) to prevent displacement; the other end of the claw connector (42) is inserted into the head cylinder barrel (49) of the hydraulic cylinder, the outer side of the other end of the head cylinder barrel (49) is provided with a Gley sealing ring (45) to prevent oil and gas leakage; a dust plug (48) is provided in the middle of the head cylinder barrel (49) and the end cylinder barrel (46); the end cylinder barrel (46) is at the outermost side of the claw (44), and an exhaust valve (47) is provided on the side of the end cylinder barrel (46).

5. The LNG ultra-low temperature pipeline emergency disconnect joint device according to claim 4 is characterized in that: The clamping claw connecting piece (42) is a planar connecting rod mechanism, one end of the hydraulic cylinder base of the planar connecting rod mechanism is connected to the outer wall body, and one end of the piston rod of the hydraulic cylinder of the planar connecting rod mechanism is connected to the clamping claw (44).

6. The LNG ultra-low temperature pipeline emergency disconnect joint device according to claim 4 or 5, characterized in that: When the hydraulic oil is pushed toward the hydraulic cylinder of the quick connection device (4), the piston in the hydraulic cylinder will move due to the oil pressure, and this movement is transmitted to the claw (44) through the claw connection piece, so that the claw (44) can open or close. By accurately controlling the flow rate and pressure of the hydraulic oil, the opening and closing speed and the clamping force of the claw (44) can be accurately regulated.

7. The LNG ultra-low temperature pipeline emergency disconnect joint device according to claim 1, characterized in that: The butterfly valve actuator transmission mechanism (2) comprises a cover plate (84), wherein an electromagnet (82), a spring (83), a cylindrical gear (93) and a rack (81) are placed inside the cover plate (84), wherein the electromagnet (82) abuts against one end of the spring (83), wherein the other end of the spring (83) is connected to the side of the rack (81), and the rack (81) is meshed with the cylindrical gear (93); the lower part of the cover plate (84) is connected to a rotating shaft (85), wherein a drip tray (90) is sleeved on the rotating shaft (85), wherein a packing (91) is screwed into the water flow tray (90) and the rotating shaft (85), and a sealing retaining ring (92) is placed on the packing (91); the butterfly valve actuator transmission mechanism (2) is used for simultaneously driving the opening and closing of the double butterfly valves, thereby ensuring the synchronization of opening and closing of the two butterfly valve devices (1) when they are in operation, and avoiding interlocking operation faults and failures.

8. The LNG ultra-low temperature pipeline emergency disconnect joint device according to claim 1, characterized in that: The butterfly valve device (1) comprises a butterfly valve body, which is connected to an end cover (87), an internal flange (86), and an external flange (88). A circular butterfly plate (96) is provided in a cylindrical channel inside the butterfly valve body. The circular butterfly plate (96) rotates around the rotation axis at an angle of 0° to 90°. When the butterfly valve rotates to 90°, the butterfly valve is in a fully open state.

9. The LNG ultra-low temperature pipeline emergency disconnect joint device according to claim 1, characterized in that: A graphite gasket and a flat gasket (7) are provided between the butterfly valve and the emergency release device to prevent leakage of the medium due to failure of the structural seal between the valve body and the valve cover of the butterfly valve and the breakaway valve.

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