CN217784862U - LNG low temperature unloading arm promptly breaks away from system - Google Patents

Abstract

The utility model relates to a LNG low temperature discharge arm promptly breaks away from system, including urgent disengaging device, chucking coupling mechanism, cold insulation mechanism and ball valve mechanism, urgent disengaging device breaks away from the body and the lower half breaks away from the body including the first one of butt joint, and chucking coupling mechanism's jack catch and dish spring hold locking again, and ball valve mechanism breaks away from originally internally including setting up two, and has the ball valve of backflow prevention structure, and cold insulation mechanism breaks away from on the cavity inner wall of body for the first one, break away from first dry layer and the first vacuum layer that the body outside direction was arranged to the first one inside supreme one of body along the first one. The utility model discloses earlier two ball valves are closed simultaneously, open the jack catch again and separate first half and break away from the body and the lower half breaks away from the body to adopt jack catch and the more reliable mode of dish spring, overcome locking and open time delay, effectively solve the outside and freeze and swell phenomenon serious problem, and the operation safety of guarantee discharge arm.

Description

LNG low temperature unloads urgent system that breaks away from of arm

Technical Field

The utility model relates to a cryogenic fluid is carried with promptly breaking away from system technical field, concretely relates to LNG low temperature unloading arm promptly breaks away from system.

Background

Liquefied Natural Gas (LNG) receiving terminals may be divided into marine receiving terminals and terrestrial receiving terminals, also referred to as LNG receiving stations. The offshore LNG receiving terminal is a new receiving terminal type proposed in recent years, and engineering examples are now available in the world. The offshore LNG receiving terminal may be further divided into a floating receiving terminal and a fixed receiving terminal, wherein the fixed receiving terminal is similar to the terrestrial receiving terminal. According to different LNG receiving terminal forms, the adopted LNG unloading modes are different. The Floating liquefied natural gas Production Storage and unloading device FLNG (LNG Floating Production Storage and offloading Unit) is a Floating Production device for offshore natural gas field development, is positioned on the sea through a mooring system, has the functions of exploiting, processing, liquefying, storing and loading and unloading natural gas, and realizes the exploitation and natural gas transportation of the offshore natural gas field by being matched with an LNG ship. The development of the offshore gas field by using the FLNG ends the single mode that the offshore gas field can only be transported to the shore by adopting a pipeline, saves the transportation cost and does not occupy land space. In addition, the FLNG can be used for the second time after the exploitation of the gas field is finished and is arranged in other natural gas fields, so that the economic performance is higher.

Terrestrial receiving terminals are now widely used worldwide and are still rapidly growing with increasing demand for natural gas. The LNG unloading arm is a rigid hinged pipeline system which is arranged on a landing terminal wharf or FLNG and used for LNG unloading, and mainly structurally comprises a rotary joint, an outer arm, an inner arm, a top end rotary joint, a base vertical pipe, a rotary joint connecting the inner arm and the base vertical pipe and other process pipelines, a supporting structure and accessories of the process pipelines. The large LNG discharge arm stands at the very front end of the LNG receiving station quay area, this height is about 50m, and the heavy natural object of 80 tons is as the key core equipment of receiving station connecting LNG ship and land pipeline and storage facility, is the "throat" of whole receiving station. After the LNG carrier arrives at a dock special for the receiving station, LNG is sent into a storage tank of the receiving station through a liquid-phase unloading arm and an unloading pipeline by using a cryogenic pump on the ship, and BOG gas in the storage tank returns to the LNG carrier through a gas return pipeline and a gas return arm. In the LNG unloading arm operation process, the end part of the unloading arm is guided to be interconnected with the receiving end of an LNG ship through a traction line, so that accurate butt joint can be achieved under the condition of relative motion, and the hydraulic system of the unloading arm is controlled to bear the influence of speed and acceleration caused by movement of a ship body.

In conclusion, the key technology of the LNG rigid discharging arm relates to various links such as low-temperature material selection, molding manufacturing and sealing, test verification and the like. The material selection and the structural design are difficult, the processing, manufacturing and system integration work are difficult, the ultra-low temperature sealing, connecting and leakage monitoring are difficult, and the whole set of low temperature discharging arm system has complex structure and high safety requirement. Whether the performance of the unloading arm is intrinsically safe or not directly influences the reliable operation of the whole system of the LNG receiving station.

The LNG transport ship carries out LNG transport operation after being connected with the unloading arm, when meetting stormy waves stream sea condition sudden change, unexpected conflagration or explosion accident etc. when unloading arm operation process when having surpassed the difference of specified working range with the safety margin, the system will start promptly breaking away from, and LNG unloading arm breaks away from with LNG transport ship deck and ship side rapidly. Simultaneously, breaking away from the in-process promptly at the system, hydraulic system can automatic locking prevent to unload the removal of arm under the wind load effect, makes the arm of unloading can not collide with other equipment after breaking away from to the safety of effectual guarantee LNG unloading arm and transport ship.

Therefore, the emergency release system is a key core component of the discharge arm, and the structural design and the operational reliability of the emergency release system are very important. The urgent system that breaks away from that present LNG low temperature unloading arm technique adopted mainly has the problem in following several respects:

(1) The prior art emergency release system has a structural design defect

Patent application No. ZL201510724353.0 discloses an emergency release device for ultralow-temperature fluid handling equipment, which comprises an upper ball valve, a lower ball valve, a valve switching mechanism for driving the two ball valves to be synchronously switched and a locking mechanism arranged on the outer edge of the butt joint surface of the two ball valves and used for controlling the two ball valves to be locked or released mutually. The mutual locking mechanism adopted by the technology is in an annular hoop type, and the problems of poor sealing performance, weak pressure bearing capacity, delay in locking and opening time and the like exist in the actual operation and application process, so that the effect of quick and safe separation is difficult to realize.

(2) The cold insulation and heat insulation effects of the emergency separation system in the prior art are not ideal

The emergency separation system in the prior art does not adopt any cold insulation and heat insulation measures, and the working temperature of LNG is about-173 ℃, so under the working condition of ultralow temperature, the temperature difference between the inside and the outside of the emergency separation system is large, and the phenomena of icing and frost heaving of the outside of the emergency separation system are very serious. As can be seen from the prior patent described in (1), in the case of freezing and frost heaving of the emergency release system in the prior art, the external mechanical transmission linkage mechanism may fail to perform linkage, which may result in the failure of the emergency release function, and thus cause serious safety accidents.

(3) Prior art emergency disconnect systems have "backflow" instability conditions

Because the quick connecting device position that promptly breaks away from the system and unloads the arm closes on, the characteristic of quick connecting device's structure, the transport process that inevitably leads to LNG to flow, the torrent appears in quick connecting device's inside, this kind of torrent belongs to the flow state of inside unstability, and is very unfavorable to the stable transmission of unloading of LNG, and the torrent can cause promptly to break away from the inside "backward flow" that produces of system simultaneously, takes place LNG against the current promptly and rocks, produces the water hammer effect when serious, influences the operation safety of unloading the arm.

Therefore, the key problems to be solved in the industries such as the defects, the unsatisfactory cold insulation and heat insulation effect, the unstable backflow situation and the like of the structural design of the LNG unloading arm emergency separation system in the prior art are solved urgently.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a LNG low temperature unloading arm promptly breaks away from system to solve among the prior art LNG unloading arm promptly break away from the problem that system structural design has defect, the adiabatic effect of cold insulation is unsatisfactory, "backward flow" unstable situation.

In order to achieve the purpose, the utility model adopts the following technical proposal:

an LNG cryogenic discharge arm emergency disconnect system, comprising:

the emergency separation device comprises an upper half separation body and a lower half separation body which are coaxially butted, wherein annular convex edge structures are outwards integrally formed at the butting ends of the upper half separation body and the lower half separation body, the other end of the upper half separation body is provided with an LNG inlet end, and the other end of the lower half separation body is provided with an LNG outlet end, so that a cavity through which liquefied natural gas flows from the LNG inlet end to the LNG outlet end is formed inside the emergency separation device;

the clamping connection mechanism comprises a clamping jaw and a disc spring, the clamping jaw is clamped on the two convex edge structures, the clamping jaw is rotatably installed on the shell of the upper half separation body, a rotatable rotating support is sleeved on the LNG inlet end of the upper half separation body, one end of the disc spring is rotatably connected to the rotating support, and the other end of the disc spring is rotatably connected to the clamping jaw, so that the disc spring is formed among the clamping jaw, the disc spring and the upper half separation body, can apply thrust to the clamping jaw in a free state, and drives the clamping jaw to clamp the triangular structure frameworks of the two convex edge structures;

the ball valve mechanism comprises a first ball valve and a second ball valve, the first ball valve is arranged on the inner side of the LNG inlet end in the emergency separation device, the second ball valve is arranged on the inner side of the LNG outlet end, and anti-backflow structures are arranged in ball passages of the first ball valve and the second ball valve;

cold insulation heat insulation mechanism, cold insulation heat insulation mechanism includes first dry layer and first vacuum layer, first dry layer and first vacuum layer are arranged in proper order to the inside supreme half direction that breaks away from the body outside along first on breaking away from the inside cavity inner wall that is close to the LNG entrance point of body in first half.

Furthermore, the rotary support is installed at the LNG inlet end in a bearing and slideway mode, a hydraulic oil cylinder is installed below the upper half part separation body, a cylinder body of the hydraulic oil cylinder is connected with the LNG inlet end through a first support rib plate, a piston of the hydraulic oil cylinder is connected with the rotary support through a second support rib plate, the first support rib plate and the second support rib plate are respectively arranged on two sides of the upper half part separation body, and the second support rib plate is in rotary connection with the piston of the hydraulic oil cylinder.

Furthermore, a plurality of groups of clamping connection mechanisms are uniformly distributed along the circumferential direction of the upper half separation body, the upper half separation body is close to the shell of the convex edge structure, a fixed rib plate is fixedly connected to the shell of the convex edge structure, each clamping jaw is of a triangular structure, a clamping opening for clamping the two convex edge structures is formed in the clamping jaw edge attached to the emergency separation device, the clamping jaw edge is arranged at the end part of the upper half separation body and is rotatably connected with the fixed rib plate, and two ends of the disc spring are rotatably connected with the rotary support and the end part of the clamping jaw far away from the emergency separation device through a pin shaft.

Further, the LNG low-temperature discharge arm emergency release system further includes a ball valve control mechanism, the ball valve control mechanism includes a rotary motor, a rotary screw, a first rotary shaft, a second rotary shaft, and a third rotary shaft, the first rotary shaft and the second rotary shaft are respectively disposed on two sides of the upper half portion of the body, and are connected to the first ball valve, the rotary screw is fixedly connected to the first rotary shaft outside the upper half portion of the body, the rotary motor is disposed on one side of the rotary screw, and a motor gear engaged with the rotary screw is fixedly connected to an output end of the rotary motor, the third rotary shaft is disposed on the same side as the second rotary shaft and connected to the second ball valve, and ends of the third rotary shaft and the second rotary shaft, which are far away from the ball valve, are connected to each other through a transmission gear set, and the rotary directions of the third rotary shaft and the second rotary shaft are opposite.

Further, first rotation axis is equipped with the polytetrafluoroethylene layer on being close to the off-axial wall of first ball valve, and inside the link that is close to first ball valve at first rotation axis, follows the first half breaks away from the body outside and is equipped with second drying layer, second vacuum layer and aerogel layer to inside direction in proper order, the intussuseption of second drying layer is filled with the molecular sieve drier this tip inside of first rotation axis is equipped with a plurality of support strengthening ribs that are parallel and first rotation axis side by side, and constitutes annular filling space between the adjacent support strengthening rib, second drying layer, second vacuum layer and aerogel layer all fill in filling space, wherein, second rotation axis and third rotation axis are unanimous with the structure of first rotation axis.

Further, the first half breaks away from the inside of body and is equipped with the connection the import inner segment pipe of LNG entrance point, just the inner of inlet inner segment pipe with first ball valve sealing connection makes the first half breaks away from this internal cavity and constitutes LNG raffinate space in the space of import inner segment pipe department, first dry layer and first vacuum layer have been arranged in proper order to the inner wall outside-in raffinate space, first dry layer intussuseption is filled with the molecular sieve drier, and first dry layer is the intercommunication setting with first vacuum layer.

Furthermore, an inert gas purging pipe is mounted on the upper half separating body, one end of the inert gas purging pipe is externally connected with a replacement gas source, and the other end of the inert gas purging pipe is communicated to the inner cavity of the upper half separating body at the position where the upper half separating body is butted with the end.

Further, the anti-backflow structure comprises an inlet section, a straight-flow section and a flow expansion section which are sequentially formed in the ball channel of the first ball valve along the direction from the LNG inlet end to the LNG outlet end, wherein the inner diameter of the inlet section gradually decreases along the direction until the inner diameter of the straight-flow section is kept unchanged, the inner diameter of the flow expansion section gradually increases along the direction, a plurality of annular grooves are uniformly distributed on the inner wall of the ball channel of the first ball valve, annular walls between adjacent annular grooves form annular blades, the annular blades are obliquely arranged in the direction in which LNG flows, the inner surface of the inlet section is an arc curve, the inner surface of the flow expansion section is a conical surface, the two sides of the annular grooves are arc surfaces, and the structure of the second ball valve is consistent with that of the first ball valve.

Further, the depth of the annular groove is gradually reduced along the direction from the inlet section to the flow expansion section;

wherein, the axial included angle between the concave surface of the annular groove or the tangent line thereof positioned in the direct current section and the ball channel in the first ball valve is set as an angle A, the included angle between the concave surface of the annular groove or the tangent line thereof positioned in the flow expansion section and the inner conical surface of the flow expansion section is set as an angle B, and the angle range of the angle A and/or the angle B is 40-70 degrees.

The utility model discloses owing to take above technical scheme, it has following beneficial effect:

1. the structure of a mutual locking mechanism of an emergency release system is innovatively designed, and the technical defects of poor sealing performance, weak bearing capacity, delay in locking and opening time and the like in the prior art are overcome by adopting a mode that a clamping jaw and a disc spring are more reliable;

2. the cold insulation and heat insulation structure is innovatively arranged in the emergency release system, so that the optimal matching of the cold insulation and heat insulation functions is realized, the serious problems of external icing and frost heaving are solved, and the operation failure of the emergency release system is prevented;

3. the ball valve mechanism adapted to the emergency separation system is provided by combining the internal flow rule of the discharging arm, so that the operation safety of the discharging arm can be guaranteed.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Like reference numerals refer to like parts throughout the drawings. In the drawings:

fig. 1 is a schematic overall structure diagram of an emergency release system for an LNG low-temperature discharge arm according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an internal structure of an emergency release system for an LNG low-temperature discharge arm according to an embodiment of the present invention;

fig. 3 is a top view of an emergency release system for an LNG low-temperature discharge arm according to an embodiment of the present invention;

fig. 4 is a schematic view of an internal anti-backflow structure of a ball valve of an emergency release system of an LNG low-temperature discharge arm according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a cold insulation and heat insulation mechanism of an emergency release system for an LNG low-temperature discharge arm according to an embodiment of the present invention;

fig. 6 is a schematic cross-sectional structure view of a first rotating shaft of an LNG low-temperature discharging arm emergency release system provided by an embodiment of the present invention.

In the drawings, the reference numerals denote the following:

1. the upper half part is separated from the body; 11. an LNG inlet end; 111. an inlet connecting bolt; 12. an inlet inner section pipe; 13. a raffinate space; 2. the lower half part is separated from the body; 21. an LNG outlet port; 211. an outlet connecting bolt; 3. a clamping connection mechanism; 31. a jaw; 32. a disc spring; 33. rotatably supporting; 34. a hydraulic cylinder; 35. A first support rib; 36. a second support rib; 37. a pin shaft; 38. a fixed rib plate; 4. a ball valve mechanism; 41. a first ball valve; 411. an inlet section; 412. a direct current section; 413. a flow expansion section; 414. an annular groove; 42. A second ball valve; 43. a rotating electric machine; 44. rotating the screw; 45. a first rotating shaft; 451. supporting the reinforcing ribs; 46. a second rotation shaft; 47. a third rotation axis; 48. a motor gear; 49. a drive gear set; 5. a cold insulation and heat insulation mechanism; 51. a first dry layer; 52. a first vacuum layer; 53. a polytetrafluoroethylene layer; 54. a second dry layer; 55. a second vacuum layer; 56. an aerogel layer; 6. the tube is purged with an inert gas.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Because there is structural design defect, the adiabatic effect of cold insulation unsatisfactory in the LNG unloading arm promptly system of breaking away from among the prior art, "backward flow" unstable situation's problem. The utility model provides a LNG low temperature unloads the arm and promptly breaks away from the system, adopt jack catch and the more reliable mode of dish spring, it is bad to overcome prior art sealing performance, bearing capacity is not strong, technical defect such as locking and opening time delay, set up the adiabatic structure of cold insulation through the innovation of promptly breaking away from the system, realize the optimization matching of the adiabatic function of cold insulation, and then solve the outside serious problem of icing and frost heaving phenomenon, prevent promptly to break away from the system operation inefficacy, and combine to unload the inside flow law of arm, propose the adaptation in the ball valve mechanism who promptly breaks away from the system, can ensure the operation safety of unloading the arm.

The embodiment of the present invention will be described in detail by way of examples.

Examples

As shown in fig. 1 and 2, the utility model provides a LNG low temperature unloading arm promptly breaks away from system, including promptly breaking away from device, chucking coupling mechanism 3, cold insulation mechanism 5 and ball valve mechanism 4, it specifically sets up as follows:

the emergency release device comprises an upper half release body 1 and a lower half release body 2 which are coaxially butted. The butt ends of the upper half separating body 1 and the lower half separating body 2 are respectively and integrally formed with a ring-shaped convex edge structure outwards. The other end that the first half breaks away from body 1 is equipped with LNG entrance point 11, and the other end that the lower half breaks away from the body is equipped with LNG exit end 21, makes the inside of urgent disengaging gear constitute the cavity that liquefied natural gas flowed through from LNG entrance point 11 to LNG exit end 21. Wherein, the shell of the upper half part separated from the body 1 is provided with inlet connecting bolts 111 around the LNG inlet end 11 for connecting and fastening with the upstream nozzle of the discharging arm, and the shell of the lower half part separated from the body 2 is provided with outlet connecting bolts 211 around the LNG outlet end 21 for connecting and fastening with the downstream nozzle of the discharging arm.

As described in connection with fig. 3, the clamp connection mechanism 3 includes a pawl 31 and a disc spring 32. The jaws 31 are clamped on two ledge structures and the jaws 31 are rotatably mounted on the housing of the disengagement body 1 in the upper half. The LNG inlet end 11 of the upper half part separated from the body 1 is sleeved with a rotatable rotating support 33, the rotating support 33 is installed at the LNG inlet end 11 in a bearing and slideway mode, a hydraulic oil cylinder 34 is installed below the upper half part separated from the body 1, the cylinder body of the hydraulic oil cylinder 34 is connected with the LNG inlet end 11 through a first supporting rib plate 35, and the piston of the hydraulic oil cylinder 34 is connected with the rotating support 33 through a second supporting rib plate 36. The first support rib 35 and the second support rib 36 are respectively provided on both sides of the upper half portion separated from the body 1, and the second support rib 36 is rotatably connected to the piston of the hydraulic cylinder 34. Through the arrangement of the structure, the reciprocating telescopic motion of the piston of the hydraulic oil cylinder 34 can be utilized to drive the rotating support 33 to rotate clockwise or anticlockwise in the circumferential direction. One end of the disc spring 32 is rotatably connected to the rotating support 33, and the other end of the disc spring 32 is rotatably connected to the jaw 31, so that the jaw 31, the disc spring 32 and the upper half part of the disc spring are separated from the body 1 to form a triangular structure frame, wherein the disc spring 32 can apply thrust to the jaw 31 in a free state, and the jaw 31 is driven to clamp two convex edge structures.

Furthermore, the chucking connection mechanisms 3 are uniformly distributed in multiple groups along the circumferential direction of the upper half part separated from the body 1, and a fixed rib plate 38 is fixedly connected to the shell of the upper half part separated from the body 1 and close to the convex edge structure. The claw 31 is a triangle structure, a clamping opening for clamping two convex edge structures is formed on the claw edge of the emergency release device, and the claw edge is arranged at the end part of the upper half release body 1 and is rotationally connected with the fixed rib plate 38. The two ends of the disc spring 32 are rotatably connected to the rotary support 33 and the end of the jaw 31 remote from the emergency release device by a pin 37, respectively.

When the clamping connection mechanism 3 is in a normal connection state, the upper half part and the lower half part of the emergency release device are kept in a pressing sealing connection through the pushing force of the disc spring 32. Meet emergency condition when unloading arm operation process, it is too big if the stormy waves flow, the conflagration or other emergency of exploding take place, unloading arm and LNG transport ship should the quickly separating, this lower half and the first half that just need urgent disengaging gear open, drive rotation support 33 along circumferential direction at hydraulic cylinder 34's piston this moment, and then drive chucking coupling mechanism 3 and produce rotation angle, effort through round pin axle 37 and dish spring 32, and the effect of rotary torque makes the jack catch 31 that originally is in clamping state open, and then realized the effect that first half and lower half break away from.

The ball valve mechanism 4 includes a first ball valve 41 disposed inside the LNG inlet port 11 inside the emergency release device, and a second ball valve 42 disposed inside the LNG outlet port 21, and the ball passages of the first ball valve 41 and the second ball valve 42 are provided with anti-backflow structures.

Further, the emergency disengaging system for the LNG cryogenic discharge arm further includes a ball valve control mechanism including a rotary motor 43, a rotary screw 44, a first rotary shaft 45, a second rotary shaft 46, and a third rotary shaft 47. The first and second rotary shafts 45 and 46 are connected to the first ball valve 41 at both sides of the upper half portion of the body 1. The rotary screw 44 is fixedly connected with the first rotary shaft 45 at the upper part separated from the outer part of the body 1, the rotary motor 43 is arranged at one side of the rotary screw 44, and the output end of the rotary motor 43 is fixedly connected with a motor gear 48 which is meshed with the rotary screw 44 for transmission. The third rotation shaft 47 is connected to the second ball valve 42 on the same side as the second rotation shaft 46, and the third rotation shaft 47 and the second rotation shaft 46 are connected by a transmission gear set 49 at ends thereof distant from the ball valves, wherein the rotation directions of the third rotation shaft 47 and the second rotation shaft 46 are opposite.

When the rotating screw 44 drives the first rotating shaft 45 to rotate, that is, the second rotating shaft 46 is synchronously driven to rotate, and when the rotating angle is 90 °, the first ball valve 41 can be in a closed state. And the second rotation shaft 46 and the third rotation shaft 47 are connected by a transmission gear set 49, so that when the first ball valve 41 is closed, the second ball valve 42 is also synchronously closed by the transmission gear set 49. It can be seen from the structural principle in fig. 3 that the two ball valves driven by the gear rotate in opposite directions to realize closing or opening, the two ball valves act synchronously, but rotate in opposite directions, and the cooperation mode also enables the emergency separation system to be balanced in internal stress, saves labor and can also act and respond quickly.

When an emergency occurs and the emergency release system is started, the two ball valves inside the emergency release system must be closed first, and then the claw 31 is opened, so that the upper half release body 1 and the lower half release body 2 are separated, and since the ball valves are closed, no LNG leakage occurs after separation. Owing to adopted the chucking coupling mechanism 3 of the jack catch formula of this kind of circumference equipartition to and gear drive reaches the structure that two inside ball valves were opened and were closed in step, compares in traditional staple bolt formula connected mode, the utility model discloses a structural scheme is simple and more reliable and stable. On one hand, the plurality of claws 31 synchronously perform opening or pressing actions under the driving of the rotating support 33, and under the acting force of the disc spring 32, the contact surfaces of the upper half part separated from the body 1 and the lower half part separated from the body 2 are stressed more uniformly, the bearing capacity is better, and the sealing performance can be better improved. On the other hand, the opening and closing of the ball valve are synchronous in action and opposite in direction, and due to the matching mode, the emergency separation system is balanced in stress inside, labor is saved, and meanwhile, quick action response can be achieved.

The contrast test result with prior art shows, adopts the utility model discloses the urgent system that breaks away from of technique, the time that jack catch 31 was opened only is 2-3s, and the current clamp formula connection structure of the same specification and dimension, and the time that the clamp was opened is about 5-7s, explains the utility model discloses the structure principle that the technique adopted is more high-efficient, and overcoming prior art sealing performance that can be fine is bad, and bearing capacity is not strong, technical defect such as locking and opening time delay.

Further, an inert gas purging pipe 6 is mounted on the upper half portion of the separation body 1, one end of the inert gas purging pipe 6 is externally connected with a replacement gas source, and the other end of the inert gas purging pipe 6 is communicated with an inner cavity of the upper half portion of the separation body 1 at a position where the upper half portion of the separation body 1 is in butt joint with the upper half portion of the separation body. It should be noted that before the emergency release system is put into service, the inert gas purging pipe is required to be used for purging and replacing the interior of the emergency release system, two sets of purging pipelines are generally symmetrically arranged, nitrogen is generally used as a replacing gas source, and the situation that explosion is generated by mixing of the LNG flowing through the interior and the air (oxygen) inside the emergency release system and the explosion of the emergency release system is caused in serious cases is prevented, which can cause irreparable safety accidents.

Further, as shown in fig. 4, the backflow prevention structure for preventing backflow includes an inlet section 411, a straight flow section 412, and a diffuser section 413 formed in sequence in a direction from the LNG inlet port 11 to the LNG outlet port 21 in the ball passage of the first ball valve 41. The inner diameter of the inlet section 411 becomes smaller along the direction until the inner diameter of the straight section 412 is kept constant, and the inner diameter of the flow expanding section 413 becomes larger along the direction. A plurality of annular grooves 414 are uniformly distributed on the inner wall of the ball passage of the first ball valve 41, so that the annular wall between adjacent annular grooves 414 forms an annular blade, and the annular blade is inclined towards the flowing direction of the LNG. Wherein, the inner surface of the inlet section 411 is a circular arc curve, the inner surface of the flow expansion section 413 is a conical surface, and both sides of the annular groove 414 are circular arc surfaces. The structure of the second ball valve 42 is the same as that of the first ball valve 41, so that two sets of backflow prevention structures are provided. Preferably, the depth of the annular groove 414 is gradually reduced in the direction from the inlet section 411 to the diffuser section 413.

As mentioned above, the angle between the concave surface of the annular groove 414 or its tangent in the straight flow section 413 and the axial direction of the ball valve mechanism 4 is defined as angle a (refer to fig. 4), the angle between the concave surface of the annular groove 414 or its tangent in the flow expansion section 412 and the inner conical surface of the flow expansion section 412 is defined as angle B, and the maximum value of the angles a and/or B should be less than 90 °, preferably in the range of 40 ° to 70 °. By utilizing the check valve structure with the annular groove 414 and the annular blades on the inner wall, the LNG flow resistance of the boundary layer on the inner wall of the ball valve can be reduced when LNG flows in the forward direction, and the flow of the LNG is facilitated. Meanwhile, when the aforementioned reverse flow, i.e., the "backflow" phenomenon occurs in the inner region of the rotary joint of the ball valve, the annular groove 414 may cause the LNG to form a vortex effect during the reverse flow process, thereby greatly increasing the reverse flow resistance, i.e., reducing the backflow of the LNG.

As shown in fig. 5 in conjunction with fig. 2, the cold insulation and heat insulation means 5 includes a first drying layer 51 and a first vacuum layer 52. The upper half part is separated from the inner wall of the chamber close to the LNG inlet end 11 in the body 1, and a first drying layer 51 and a first vacuum layer 52 are sequentially arranged from outside to inside. Specifically, an inlet inner section pipe 12 connected with the LNG inlet end 11 is arranged inside the upper half portion separated from the body 1, and the inner end of the inlet inner section pipe 12 is hermetically connected with the first ball valve 41, so that a residual liquid space 13 is formed in a space of the inlet inner section pipe 12 of a cavity in the upper half portion separated from the body 1. When the first ball valve 41 is in an open state, that is, in the state shown in the figure, the end of the inlet inner-section pipe 12 is spaced apart from the left end of the first ball valve 41, and when LNG flows inside the emergency release apparatus, the LNG inevitably flows into the raffinate space 13 along the path of the distance, so that a first drying layer 51 and a first vacuum layer 52 are sequentially disposed on the inner wall of the raffinate space 13 from the outside to the inside, the first drying layer 51 is filled with a molecular sieve drying agent preferably 13XAPG, and the first drying layer 51 and the first vacuum layer 52 are disposed in a communication manner. The molecular sieve-based drying agent is an aluminosilicate compound with a cubic lattice, silicon and aluminum are connected through oxygen bridges to form a hollow framework structure, a plurality of pore channels with uniform pore diameters and holes which are arranged in order and have large internal surface areas are formed in the structure, free water can be stably adsorbed in the holes, a vacuum layer connected with the holes can be kept to play a role for a long time, and through the structural arrangement of the molecular sieve drying agent and the vacuum layer 52, the heat exchange between LNG low-temperature fluid in a residual liquid space 13 and the outside is effectively reduced, so that good cold-keeping and heat-insulating effects are achieved.

One preferred embodiment is: as shown in fig. 4 and 6, the consideration of heat insulation and cold insulation is more necessary considering that the corresponding rotating shaft connected to the valve body of the ball valve is directly in contact with the external environment. The embodiment of the utility model provides a be equipped with polytetrafluoroethylene layer 53 on the first rotation axis 45 is close to the off-axial wall of first ball valve 41, and inside first rotation axis 45 is close to the link of first ball valve 41, it is equipped with second dry layer 54 to the inside direction in proper order to break away from the body 1 outside along first, second vacuum layer 55 and aerogel layer 56, second dry layer 54 intussuseption is filled with the molecular sieve drier, the gel is a nanometer porous solid-state material, effectively restrict local heat conduction through the fine nanometer network structure of aerogel, and then obtain the adiabatic effect of cold preservation of ideal. A plurality of coaxial supporting reinforcing ribs 451 are sequentially sleeved inside the end portion of the first rotating shaft 45, an annular filling space is formed between two adjacent supporting reinforcing ribs 451, and the second drying layer 54, the second vacuum layer 55 and the aerogel layer 56 are filled in the filling space. Wherein the second and third rotation shafts 46 and 47 are identical in structure to the first rotation shaft 45.

As mentioned above, polytetrafluoroethylene, commonly known in the industry as PTFE, is a high molecular weight polymer made by polymerizing tetrafluoroethylene as a monomer. Can be used for a long time at-180 to 260 ℃. The material has good toughness and rigidity, and also has certain cold insulation effect, so the material is arranged outside the rotating shaft. The utility model discloses a position innovation such as raffinate space 13 walls, inside ball valve body, ball valve rotation axis sets up cold insulation and heat insulation structure to realize the optimal combination matching of cold insulation and heat insulation function, effectively solved outside and iced and bloated phenomenon serious problem, prevent promptly to break away from the system operation inefficacy.

Based on foretell LNG low temperature unloads urgent disengagement system of arm, its specific operation is as follows:

starting the ball valve control mechanism and closing the first ball valve 41 in the upper half separating body 1 and the second ball valve 42 in the lower half separating body 2 at the same time;

after the two ball valves are closed simultaneously, the clamping connection mechanism 3 is started, the clamping claws 31 are opened to clamp the two convex edge structures, and the upper half part is separated from the body 1 and the lower half part is separated from the body 2;

and after the emergency situation is processed, interconnecting and butting the separated emergency separation devices again according to the steps opposite to the separation process, recovering the working state, and continuously finishing the LNG conveying operation.

The utility model discloses following beneficial effect has:

1. the structure of a mutual locking mechanism of an emergency release system is innovatively designed, a clamping connection mechanism 3 combining a jack catch 31 pin shaft 37 and a disc spring 32 is more reliable, and the technical defects of poor sealing performance, weak bearing capacity, delay in locking and opening time and the like in the prior art are overcome;

2. the cold insulation and heat insulation mechanism 5 is innovatively arranged in the emergency release system, so that the optimal matching of the cold insulation and heat insulation functions is realized, the serious problems of external icing and frost heaving are solved, and the operation failure of the emergency release system is prevented;

3. the ball valve mechanism 4 adapted to the emergency separation system is provided by combining the flow rule in the discharging arm, so that the operation safety of the discharging arm can be guaranteed.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (9)

1. The utility model provides a LNG low temperature discharge arm promptly breaks away from system which characterized in that, LNG low temperature discharge arm promptly breaks away from the system includes:

the emergency separation device comprises an upper half separation body and a lower half separation body which are coaxially butted, wherein annular convex edge structures are outwards integrally formed at the butting ends of the upper half separation body and the lower half separation body, the other end of the upper half separation body is provided with an LNG inlet end, and the other end of the lower half separation body is provided with an LNG outlet end, so that a cavity through which liquefied natural gas flows from the LNG inlet end to the LNG outlet end is formed inside the emergency separation device;

the clamping connection mechanism comprises clamping claws and disc springs, the clamping claws are clamped on the two convex edge structures, the clamping claws are rotatably mounted on the shell of the upper half part separating body, a rotatable rotating support is sleeved on the LNG inlet end of the upper half part separating body, one end of each disc spring is rotatably connected to the rotating support, and the other end of each disc spring is rotatably connected to the clamping claws, so that the disc springs formed among the clamping claws, the disc springs and the upper half part separating body can apply thrust to the clamping claws in a free state and drive the clamping claws to clamp the triangular structure frameworks of the two convex edge structures;

the ball valve mechanism comprises a first ball valve and a second ball valve, the first ball valve is arranged on the inner side of the LNG inlet end in the emergency separation device, the second ball valve is arranged on the inner side of the LNG outlet end, and anti-backflow structures are arranged in ball passages of the first ball valve and the second ball valve;

cold insulation heat insulation mechanism, cold insulation heat insulation mechanism includes first dry layer and first vacuum layer, first dry layer and first vacuum layer are arranged in proper order to the inside supreme half direction that breaks away from the body outside along first on breaking away from the inside cavity inner wall that is close to the LNG entrance point of body in first half.

2. An LNG cryogenic discharge arm emergency disconnect system of claim 1, wherein: the LNG inlet end is provided with a rotary support, the rotary support is arranged at the LNG inlet end in a bearing and slideway mode, a hydraulic oil cylinder is arranged below the upper half separation body, a cylinder body of the hydraulic oil cylinder is connected with the LNG inlet end through a first support rib plate, a piston of the hydraulic oil cylinder is connected with the rotary support through a second support rib plate, the first support rib plate and the second support rib plate are respectively arranged at two sides of the upper half separation body, and the second support rib plate is in rotary connection with the piston of the hydraulic oil cylinder.

3. An LNG cryogenic discharge arm emergency disconnect system of claim 1, wherein: the clamping connection mechanism is characterized in that a plurality of groups of clamping connection mechanisms are uniformly distributed along the circumferential direction of the upper half separation body, the upper half separation body is close to the shell of the convex edge structure, a fixed rib plate is fixedly connected onto the shell of the convex edge structure, the clamping jaw is of a triangular structure, a clamping opening for clamping two convex edge structures is formed in the edge of the clamping jaw attached to the emergency separation device, the clamping opening is arranged at the end part of the upper half separation body in a rotating mode and is connected with the fixed rib plate, and the two ends of the disc spring are respectively connected with the rotating support and the end part of the clamping jaw far away from the emergency separation device in a rotating mode through pin shafts.

4. An LNG cryogenic discharge arm emergency disconnect system of claim 1, wherein: the LNG low temperature unloading arm emergency separation system further comprises a ball valve control mechanism, wherein the ball valve control mechanism comprises a rotary motor, a rotary screw, a first rotary shaft, a second rotary shaft and a third rotary shaft, the first rotary shaft and the second rotary shaft are respectively arranged on the two sides of the upper half separation body and connected with the first ball valve, the rotary screw is arranged on the outer side of the upper half separation body and fixedly connected with the first rotary shaft, the rotary motor is arranged on one side of the rotary screw, a motor gear meshed with the rotary screw and driven is fixedly connected to the output end of the rotary motor, the third rotary shaft is arranged on the same side as the second rotary shaft and connected with the second ball valve, the third rotary shaft and the end part, far away from the ball valve, of the second rotary shaft are connected through a transmission gear set, and the rotation direction of the third rotary shaft and the rotation direction of the second rotary shaft are opposite.

5. An LNG cryogenic discharge arm emergency disconnect system of claim 4, characterized in that: first rotation axis is equipped with the polytetrafluoroethylene layer on being close to the off-axial wall of first ball valve, and inside first rotation axis is close to the link of first ball valve, follows first half breaks away from body outside and is equipped with second drying layer, second vacuum layer and aerogel layer to inside direction in proper order, second drying layer intussuseption is filled with the molecular sieve drier, is equipped with a plurality of covers in proper order and establishes and coaxial support strengthening muscle in this tip of first rotation axis inside, and adjacent two support and constitute annular filling space between the strengthening muscle, second drying layer, second vacuum layer and aerogel layer all fill in filling space, wherein, the structure of second rotation axis and third rotation axis and first rotation axis is unanimous.

6. An LNG cryogenic discharge arm emergency disconnect system of claim 1, wherein: first inside that breaks away from the body is equipped with the connection the import inner segment pipe of LNG entrance point, just the inner of inlet inner segment pipe with first ball valve sealing connection makes first cavity in this body breaks away from constitutes LNG raffinate space in the space of import inner segment pipe department, first dry layer and first vacuum layer have been arranged in proper order to the inner wall in raffinate space outside-in, first dry in situ is filled with the molecular sieve drier, and first dry layer is the intercommunication setting with first vacuum layer.

7. An LNG cryogenic discharge arm emergency disconnect system of claim 1, wherein: an inert gas purging pipe is mounted on the upper half separating body, one end of the inert gas purging pipe is externally connected with a replacement gas source, and the other end of the inert gas purging pipe is communicated to an inner cavity of the upper half separating body at the position of the butt joint end of the upper half separating body.

8. An LNG cryogenic discharge arm emergency disconnect system of claim 1, wherein: the anti-backflow structure comprises an inlet section, a direct-flow section and a flow expansion section which are sequentially formed in the direction from the LNG inlet end to the LNG outlet end in the spherical channel of the first ball valve, wherein the inner diameter of the inlet section is gradually reduced along the direction until the direct-flow section keeps unchanged, the inner diameter of the flow expansion section is gradually increased along the direction, a plurality of annular grooves are uniformly distributed on the inner wall of the spherical channel of the first ball valve, annular walls between adjacent annular grooves form annular blades, the annular blades are obliquely arranged in the direction in which LNG flows, the inner surface of the inlet section is an arc curve, the inner surface of the flow expansion section is a conical surface, the two sides of the annular grooves are arc surfaces, and the structure of the second ball valve is consistent with that of the first ball valve.

9. An LNG cryogenic discharge arm emergency disconnect system of claim 8, wherein: the depth of the annular groove is gradually reduced along the direction from the inlet section to the flow expansion section;

wherein, the axial included angle between the concave surface of the annular groove in the direct current section or the tangent line thereof and the spherical channel in the first ball valve is set as an angle A, the included angle between the concave surface of the annular groove in the flow expansion section or the tangent line thereof and the inner conical surface of the flow expansion section is set as an angle B, and the angle range of the angle A and/or the angle B is 40-70 degrees.

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