CN113970066A

CN113970066A - A device that is used for inside heat preservation of LNG storage tank to subside on-line measuring

Info

Publication number: CN113970066A
Application number: CN202010702750.9A
Authority: CN
Inventors: 钟君儿; 蔺学江; 严艺敏; 刘立冬
Original assignee: Tianjin Incom Science & Technology Development Co ltd; Shanghai Lng Co ltd
Current assignee: Tianjin Incom Science & Technology Development Co ltd; Shanghai Lng Co ltd
Priority date: 2020-07-21
Filing date: 2020-07-21
Publication date: 2022-01-25
Anticipated expiration: 2040-07-21
Also published as: CN113970066B

Abstract

The invention provides a device for online detection of sedimentation of an insulating layer in an LNG storage tank, which comprises a safety valve box, a measuring guide rail and a measuring probe, wherein the measuring probe is arranged on the safety valve box; the safety valve box comprises a valve box main body, a valve base and an operation and control assembly, the valve base is connected with the detection port in a sealing mode, and an inflation interface is arranged on the valve box main body; the measuring guide rail comprises a first rod piece, a second rod piece capable of moving up and down and a connecting joint, the second rod piece is rotatably connected with the first rod piece through the connecting joint, the measuring probe is connected to the lower end of the first rod piece, and the extending direction of the connecting line between the control assembly and the measuring probe is consistent with the extending direction of the first rod piece and the second rod piece; the measuring probe is a temperature measuring probe or a settlement height measuring probe. The method and the device can realize the settlement on-line detection of the heat insulation layer in the LNG storage tank, are safe to operate and can ensure the normal production of the LNG storage tank; the measuring guide rail is of a bendable structure and is suitable for the LNG storage tank with the horizontal offset between the detection port and the annular area.

Description

A device that is used for inside heat preservation of LNG storage tank to subside on-line measuring

Technical Field

The invention relates to the field of LNG storage tank detection, in particular to a device for online detection of sedimentation of an internal heat-insulating layer of an LNG storage tank.

Background

Currently, each large LNG receiving station is provided with an LNG storage tank for storing LNG (liquefied natural gas), which is a core device of the LNG receiving station.

As shown in fig. 1, the LNG storage tank includes an inner tank, an elastic felt 71, a heat insulating layer 72, and an outer tank 73 in this order from inside to outside, the upper portion of the inner tank is an aluminum ceiling 74, rock wool 75 is filled in the aluminum ceiling 74, an outer region of an upper end of the aluminum ceiling 74, and an annular region between the elastic felt 71 and an inner wall of the outer tank 73 are filled in the heat insulating layer 72, and the rock wool 75 and the heat insulating layer 72 are separated from each other by a glass cloth 76 at the upper portion of the aluminum ceiling 74. Further, the pipe wall of the inner tank is made of 9% Ni steel and is resistant to low temperature; the elastic felt 71 buffers the expansion and contraction amount of the inner tank wall and plays a role in heat preservation; the outer tank 73 is made of concrete, and the inner wall of the outer tank 73 is a low-temperature carbon steel plate with the design temperature of-20 ℃; the insulation 72 is composed of perlite. In addition, a plurality of filling openings 77 extending up and down are formed in the tank top of the LNG storage tank, the filling openings 77 are aligned to the outer side area of the upper end of the aluminum ceiling 74, and perlite enters the outer side area of the upper end of the aluminum ceiling 74 from the filling openings 77 and then enters the annular area between the elastic felt 71 and the inner wall of the outer tank 73, so that the heat insulation layer 72 of the LNG storage tank is formed. In addition, the space outside the upper part of the aluminum ceiling 74 is also a perlite cold storage warehouse at the same time for supplementing the sinking of perlite.

Further, the perlite filled in the annular region between the elastic felt 71 and the inner wall of the outer tank 73 in the LNG storage tank can be settled due to the materials of the perlite, the construction quality of the perlite, the expansion and contraction of the LNG storage tank during operation, the materials of the elastic felt 71, the construction quality of the elastic felt 71 and the like, and the perlite is settled to form a settlement region 78, as shown in fig. 2, the settlement region 78 of the perlite enables only the elastic felt 71 at the upper part of the annular space to keep warm, the cold energy of the LNG in the LNG storage tank can be easily transferred to the inner wall of the outer tank 73 and further transferred to the outer wall of the outer tank 73, and the outer wall of the outer tank 73 is also the outer wall of the LNG storage tank, so that the corresponding position of the outer wall of the LNG storage tank is frosted, dewed and even frozen. The more the perlite settles, the more the cold transfer is, and the lower the temperature of the inner wall steel plate and the outer wall of the outer tank 73 of the LNG storage tank is.

In order to accurately evaluate whether the LNG storage tank needs to be supplemented with perlite and estimate the amount of perlite to be supplemented, it is necessary to perform a perlite sedimentation test in the LNG storage tank, which generally includes a perlite sedimentation height test and an outer tank inner wall temperature test.

In the prior art, the settlement detection of perlite in an LNG storage tank mainly comprises an infrared camera shooting method for the outer wall of the storage tank and an internal probe insertion method. The infrared camera shooting method for the outer wall of the storage tank is used for measuring the temperature of the outer wall of the storage tank through infrared camera shooting, but cannot be used for measuring the temperature of the inner wall of an outer tank in the storage tank; in addition, the settlement height of the perlite is estimated through the temperature field distribution of the outer wall of the LNG storage tank, and the temperature field distribution of the outer wall of the LNG storage tank is related to the settlement height of the perlite and possibly the state of the elastic felt, so that the settlement height of the perlite is not accurately measured. The internal probe insertion method is used for detecting the settlement height of the perlite, and the internal probe insertion method extends into a filling area of the perlite through a filling opening, but is only suitable for an LNG storage tank with the filling opening aligned with an annular area between an elastic felt and the inner wall of an outer tank. When the filling opening is not aligned with the annular area between the elastic felt and the inner wall of the outer tank and a horizontal offset of about 1.2 meters exists between the filling opening and the annular area, as shown in fig. 2, the internal probe insertion method cannot accurately detect the settlement height of the perlite. When the perlite is settled and detected, the filling port for inserting the inner probe forms a detection port.

In order to obtain a relatively accurate evaluation effect and ensure the operation safety of the LNG storage tank, it is necessary to develop an effective and reliable online detection device for the settlement of the insulating layer.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention provides an apparatus for detecting the settlement of the heat insulation layer inside an LNG storage tank on line, which can detect the settlement height of the heat insulation layer on line and is suitable for an LNG storage tank with a horizontal offset between the detection port and the annular area.

In order to achieve the purpose, the invention provides a device for detecting the sedimentation of an insulating layer in an LNG storage tank on line, which comprises a safety valve box, a measuring guide rail and a measuring probe; the safety valve box comprises a valve box main body, a valve base and an operation and control assembly, wherein the valve base is connected to the lower end of the valve box main body in a sealing mode, the operation and control assembly is installed on the valve box main body, the lower end of the valve base is used for being connected with a detection port on the LNG storage tank in a sealing mode, the operation and control assembly is connected with the measuring probe through a connecting wire, and an inflation port communicated with the interior of the valve box main body is arranged on the valve box main body; the measurement guide rail comprises a first rod piece which can be placed in the LNG storage tank, a second rod piece which can be vertically moved and penetrates through the valve box main body and the valve base, and a connecting joint, a sealing piece is arranged between the upper end of the second rod piece and the valve box main body, the lower end of the second rod piece is rotatably connected with the upper end of the first rod piece through the connecting joint, the measurement probe is connected with the lower end of the first rod piece, and the extending direction of the connecting line between the control assembly and the measurement probe is consistent with the extending direction of the first rod piece and the second rod piece; the measuring probe is a temperature measuring probe or a settlement height measuring probe.

Further, the link includes fixed connection at the first connecting piece of first member upper end, connects at the second connecting piece of second member lower extreme, rotates the pivot that links to each other and the cover with first connecting piece and second connecting piece and establish the epaxial torsional spring in the pivot, be equipped with first spacing portion on the first connecting piece, be equipped with the spacing portion of second on the second connecting piece, first spacing portion and the spacing butt cooperation of portion of second, the one end of torsional spring links to each other with first connecting piece, applys the effort that makes first spacing portion towards the spacing portion of second to first connecting piece.

Further, control the subassembly including the transmission shaft of horizontal extension, fix the epaxial wire reel of transmission and fix the hand wheel at the transmission shaft tip, the transmission shaft is rotationally installed in the valve box main part, the wire reel is located the inside of valve box main part, the connecting wire winding is on the wire reel, the hand wheel is located the outside of valve box main part.

Further, when the measuring probe is a temperature measuring probe, the connecting wire is a thermocouple connecting wire.

Further, install temperature instrument on the valve box main part, the thermocouple connecting wire links to each other with temperature instrument.

Further, when the measuring probe is a probe for measuring the sedimentation height, the connecting wire is a wear-resistant connecting wire.

Further, the control assembly comprises a horizontally extending spring, two ends of the spring are connected with the valve box main body, and the connecting line penetrates through the spring; the probe for measuring the sedimentation height is a copper pendant probe.

Further, the valve box main body is provided with an observation port.

Further, flange sealing connection is respectively arranged between the valve box main body and the valve base and between the valve base and the detection port of the LNG storage tank.

Further, a pressure gauge is installed on the valve box main body, and a pressure measuring end of the pressure gauge is located in the valve box main body.

As described above, the device for detecting the sedimentation of the heat insulation layer inside the LNG storage tank on line according to the present invention has the following advantages:

the settlement height of heat preservation in the on-line measuring LNG storage tank can be realized to this application, including the settlement height that detects the heat preservation and the inner wall temperature of outer jar in the heat preservation settlement department in detecting the LNG storage tank, its operation safety just can guarantee the normal production of LNG storage tank. Particularly, measure the guide rail in this application and be flexible structure, be applicable to the LNG storage tank that the annular region that detects mouth and heat preservation subside department on the LNG storage tank has horizontal offset. Therefore, the settlement condition of the heat preservation layer in the LNG storage tank can be accurately detected, accurate data are provided for accurately evaluating whether the LNG storage tank needs to be supplemented with perlite and estimating the amount of the perlite needing to be supplemented, and finally the operation safety of the LNG storage tank is ensured.

Drawings

Fig. 1 is a schematic structural view of an LNG storage tank.

Fig. 2 is a schematic structural diagram of the settled perlite in the LNG storage tank.

FIG. 3 is a structural schematic diagram of a device that is used for inside heat preservation of LNG storage tank to subside on-line measuring in this application.

Fig. 4 is an enlarged view of a frame a of fig. 3.

Fig. 5 is an enlarged view of the B frame of fig. 3.

Fig. 6 is a top perspective view of fig. 5.

Fig. 7 is a schematic structural diagram of a measurement rail in the present application.

Fig. 8 is a schematic structural view of the connection joint in fig. 7.

Description of the element reference numerals

10 safety valve box

11 valve box main body

12 valve base

13 operating assembly

131 drive shaft

132 wire spool

133 handwheel

134 spring

14 inflation interface

15 temperature instrument

16 viewing port

17 safety valve

18 pressure gauge

19 oil seal fixing device

110 anti-falling fastener

20 measuring guide rail

21 first bar member

22 second bar

23 connecting joint

231 first connecting piece

232 second connecting piece

233 rotating shaft

234 torsion spring

235 first position-limiting part

236 second limit part

24 third bar

30 measuring probe

40 connecting wire

50 sealing element

60 detection port

61 ball valve

71 elastic felt

72 insulating layer

73 outer pot

74 aluminum ceiling

75 rock wool

76 glass cloth

77 filling port

78 settling zone

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

It should be understood that the structures, proportions, and dimensions shown in the drawings and described herein are for illustrative purposes only and are not intended to limit the scope of the present invention, which is defined by the claims, but rather by the claims. In addition, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for convenience of description only and are not intended to limit the scope of the present invention, and changes or modifications of the relative relationship thereof may be made without substantial technical changes and modifications.

The application provides a device (the following short for on-line measuring device) that is arranged in inside heat preservation of LNG storage tank to subside on-line measuring detects heat preservation 72's settlement in the LNG storage tank through this on-line measuring device, should subside and detect the inner wall temperature of outer jar 73 in heat preservation settlement zone 78 department in detecting heat preservation 72's settlement height and detecting the LNG storage tank. In the following embodiments, the insulating layer 72 is an expanded perlite insulating layer; as shown in fig. 2, the subsidence area 78 of the thermal insulation layer 72 in the LNG tank is an annular area which is horizontally offset from the filling port 77 of the LNG tank serving as the inspection port 60 by a horizontal offset of about 1.2 m, and which is also located between the elastic felt 71 in the LNG tank and the inner wall of the outer tank 73. As shown in fig. 5, a ball valve 61 is disposed in the detection port 60 of the LNG storage tank, and the detection port 60 can be opened or closed by the ball valve 61.

As shown in fig. 3, the on-line inspection apparatus according to the present application includes a safety valve box 10, a measurement rail 20, and a measurement probe 30. As shown in fig. 4 and 5, the safety valve box 10 includes a valve box main body 11, a valve base 12 hermetically connected to a lower end of the valve box main body 11, and an operating assembly 13 installed on the valve box main body 11, a lower end of the valve base 12 is configured to be hermetically connected to an upper end of a detection port 60 on the LNG storage tank, the operating assembly 13 is connected to the measurement probe 30 through a connection line 40, and an inflation port 14 communicated with an interior of the valve box main body 11 is disposed on an upper end surface of the valve box main body 11. As shown in fig. 3 and 4, and fig. 7 and 8, the measuring guide rail 20 at least includes a first rod 21, a second rod 22 connected to the upper end of the first rod 21, and a connecting joint 23, the second rod 22 is vertically movably inserted into the valve box main body 11 and the valve base 12, a sealing member 50 is disposed between the upper end of the second rod 22 and the valve box main body 11, the lower end of the second rod 22 is rotatably connected to the upper end of the first rod 21 through the connecting joint 23, the measuring probe 30 is connected to the lower end of the first rod 21, and the extending direction of the connecting line 40 between the manipulating assembly 13 and the measuring probe 30 is consistent with the extending direction of the first rod 21 and the second rod 22; when the settlement of the insulating layer 72 is measured on line, the first rod 21 extends into the LNG tank, and the lower section of the second rod 22 also extends into the LNG tank. The measuring probe 30 is a temperature measuring probe or a settlement height measuring probe; when the temperature of the inner wall of the middle and outer tank 73 of the LNG storage tank at the heat insulation layer settlement area 78 is detected on line, the measuring probe 30 is a temperature measuring probe, namely the temperature measuring probe is arranged at the lower end of the first rod piece 21; when the settlement height of the insulating layer 72 is detected on line, the measuring probe 30 is a settlement height probe, that is, the settlement height probe is arranged at the lower end of the first rod 21.

After the online detection device is connected with the detection port 60 on the LNG storage tank, the lower end of the valve base 12 is connected with the upper end of the detection port 60 in a sealing manner, the upper end of the valve base 12 is connected with the lower end of the valve box main body 11 in a sealing manner, and the second rod piece 22 in the control assembly 13 is also connected with the valve box main body 11 in a sealing manner, so that the online detection device is of a self-sealing structure integrally, the connection part of the online detection device and the detection port 60 on the LNG storage tank is also in a sealing state, and the BOG gas with pressure in the LNG storage tank is prevented from being leaked outwards during subsequent detection. Before the detection starts, gas is filled into the valve box main body 11 through an inflation interface 14 on the valve box main body 11, so that the internal pressure of the safety valve box 10 is greater than the internal pressure of the LNG storage tank, and the pressure maintaining effect is achieved; after the ball valve 61 of the detection port 60 on the LNG storage tank is opened, because the internal pressure of the safety valve box 10 is greater than the internal pressure of the LNG storage tank, the BOG gas with pressure in the LNG storage tank is effectively prevented from leaking outwards, the detection requirement of the LNG storage tank under the normal operation working condition of the BOG gas with pressure is met, and therefore online detection is realized and the operation safety of online detection is ensured. In the detection process, as the first rod 21 is rotatably mounted on the second rod 22 through the connecting joint 23, the first rod 21 can be bent relative to the vertically extending second rod 22, and therefore, the lower end of the first rod 21 drives the temperature probe or the sedimentation height measuring probe to move together into the annular region of the heat insulation layer sedimentation region 78 until the annular region abuts against the inner wall of the outer tank 73, so that the sedimentation height of the heat insulation layer 72 and the temperature of the inner wall of the outer tank 73 at the heat insulation layer sedimentation region 78 are accurately detected, accurate data are provided for accurately evaluating whether the LNG storage tank needs to be supplemented with perlite and estimating the amount of the perlite needing to be supplemented, and finally the operation safety of the LNG storage tank is ensured. Therefore, the settlement of the heat preservation layer 72 in the LNG storage tank can be detected on line in the application, including the settlement height of the heat preservation layer 72 and the inner wall temperature of the outer tank 73 at the heat preservation layer settlement area 78 in the LNG storage tank, the operation is safe, and the normal production of the LNG storage tank can be ensured. In particular, the measurement guide rail 20 in this application is a bendable structure, and is suitable for the LNG storage tank that there is horizontal offset in the annular region of detection mouth 60 and heat preservation settlement zone 78 department on the LNG storage tank.

Preferably, in this embodiment, the inflation inlet 14 is a nitrogen inlet, that is, the gas filled in the forward valve box main body 11 is detected to be nitrogen. The seal 50 connected between the second rod 22 and the valve housing main body 11 is a seal oil seal. In addition, as shown in fig. 4, the safety valve box 10 is provided with an oil seal fixing device 19 on the outer periphery side of the sealed oil seal, the upper end of the second rod 22 is detachably connected with an anti-falling clamp 110 located above the oil seal fixing device 19, the anti-falling clamp 110 can be abutted against the oil seal fixing device 19, the measurement guide rail 20 can be prevented from falling down completely by the anti-falling clamp 110, and the operation safety is ensured.

Further, as shown in fig. 7 and 8, the connection joint 23 includes a first connection member 231 fixedly connected to the upper end of the first rod member 21, a second connection member 232 connected to the lower end of the second rod member 22, a rotation shaft 233 rotatably connecting the first connection member 231 and the second connection member 232, and a torsion spring 234 sleeved on the rotation shaft 233, the first connection member 231 is provided with a first limiting portion 235, the second connection member 232 is provided with a second limiting portion 236, the first limiting portion 235 is in butt fit with the second limiting portion 236, one end of the torsion spring 234 is connected with the first connection member 231, an acting force is applied to the first connection member 231 to enable the first limiting portion 235 to face the second limiting portion 236, and anti-separation retaining rings are fixedly arranged at two ends of the rotation shaft 233. Preferably, the fixed connection between the first rod 21 and the first connector 231 may be a threaded connection, and the fixed connection between the second rod 22 and the second connector 232 may also be a threaded connection. After the connecting member with the above structure is adopted, when an acting force overcoming the elasticity of the torsion spring 234 is applied to the first rod 21 and the first connecting member 231, the first rod 21 and the first connecting member 231 rotate in a direction close to the vertical center line of the second rod 22, the first limiting portion 235 is far away from the second limiting portion 236, and the collinearity of the first rod 21 and the second rod 22 can be realized. After the acting force applied to the first rod 21 and the first connecting member 231 is removed, the elastic force of the torsion spring 234 causes the first rod 21 and the first connecting member 231 to rotate in the direction away from the vertical center line of the second rod 22 until the first limiting portion 235 abuts against the second limiting portion 236, or the first rod 21 can be in a stable open state under the action of the torsion spring 234 and the abutting and matching action of the first limiting portion 235 and the second limiting portion 236, as shown in fig. 3 or fig. 7, in this embodiment, when the first rod 21 is opened, the included angle θ between the first rod 21 and the second rod 22 is 43 °, or when the measuring guide rail 20 is in a natural state, the first rod 21 is in a 43 ° bent state. Preferably, the first rod 21 and the second rod 22 are both hollow rods, the first connecting member 231 is provided with a connecting hole communicating with the hollow area inside the first rod 21, the connecting wire 40 is distributed on the second rod 22 outside the second rod 22 and arranged along the second rod 22, and then the connecting wire 40 penetrates into the first rod 21 from the connecting hole on the first connecting member 231 and arranged along the first rod 21. The inner space of the first rod 21 can accommodate a temperature probe and a settlement height probe.

Further, as shown in fig. 3, the measurement guide rail 20 in this application further includes a third rod 24, the third rod 24 is located outside the safety valve box 10, a lower end of the third rod 24 is fixedly connected to an upper end of the second rod 22, and the third rod and the second rod are coaxial, the length of the measurement guide rail 20 can be extended by the third rod 24, and the up-and-down movement of the second rod 22 is conveniently controlled, so that the moving position of the first rod 21 is conveniently controlled, and the first rod 21 can accurately reach the annular region where the heat insulation layer is settled. In addition, the first rod 21, the second rod 22, the third rod 24, the first connecting piece 231 and the second connecting piece 232 in the measurement guide rail 20 are all made of carbon fiber, so the measurement guide rail 20 is light, wear-resistant, high in strength, explosion-proof and anti-static, convenient to control, and particularly suitable for the ultra-low temperature inside the LNG storage tank and the severe dangerous working conditions full of combustible gas. When the third rod member 24 is connected to the upper end of the second rod member 22, the anti-dropping fastener 110 at the upper end of the second rod member 22 is taken down, and the anti-dropping fastener 110 is connected to the upper end of the third rod member 24, so that the measurement guide rail 20 is prevented from falling down completely, and the operation safety is guaranteed. Therefore, the anti-falling clamp 110 and the second rod 22, and the anti-falling clamp 110 and the third rod 24 are detachably connected.

Further, as shown in fig. 4 and 6, the manipulating assembly 13 includes a horizontally extending transmission shaft 131, a wire spool 132 fixed to the transmission shaft 131, and a hand wheel 133 fixed to an end of the transmission shaft 131, the transmission shaft 131 is rotatably installed in the valve housing main body 11, the wire spool 132 is located inside the valve housing main body 11, the connecting wire 40 is wound on the wire spool 132, and the hand wheel 133 is located outside the valve housing main body 11. During measurement, the hand wheel 133 is rotated to drive the transmission shaft 131 and the wire spool 132 to rotate together, so that the wire 40 is paid off and taken up.

In the present application, when the measurement probe 30 is a temperature measurement probe, the connection line 40 is a thermocouple connection line; the temperature measuring probe is preferably a dual-probe thermal resistance sensor. When the measuring probe 30 is a probe for measuring the sedimentation height, the connecting wire 40 is a low temperature resistant and wear resistant connecting wire.

Preferably, as shown in fig. 4, a temperature meter 15 is installed on the valve box main body 11, and the thermocouple connecting wire is connected with the temperature meter 15, so that the reading of temperature measurement data is facilitated. The valve box main body 11 is provided with a safety valve 17 to improve the operation safety. Install manometer 18 on the valve box main part 11, the pressure measurement end of manometer 18 is located valve box main part 11, can accurately measure the internal pressure of valve box main part 11 through manometer 18, makes things convenient for the measurement personnel to know whether the internal pressure of safety valve box 10 reaches the requirement when aerifing to valve box main part 11 through aerifing interface 14.

Further, as shown in fig. 4 and 6, the manipulating assembly 13 includes a horizontally extending spring 134, both ends of the spring 134 are connected to the valve housing main body 11, and the connection line 40 passes through the spring 134; the probe for measuring the sedimentation height is a copper pendant probe; when the settlement height of the heat insulation layer 72 is detected, if the copper pendant probe is not abutted to the heat insulation layer 72 below the annular region, the copper pendant probe is in a naturally drooping state, acting force is applied to the connecting wire 40, and the connecting wire 40 acts on the spring 134 to enable the spring 134 to be in a stretched state; if the copper pendant probe abuts the insulating layer 72 below the annular region, the copper pendant probe is held, the acting force applied to the connecting wire 40 disappears, and the spring 134 is in a natural unstretched state. Therefore, by determining the state of the spring 134, it can be determined whether the copper pendant probe is in contact with the insulation layer 72. Preferably, the valve box main body 11 is provided with an observation port 16, so that a tester can observe the state of each component in the valve box main body 11 conveniently, and the observation port 16 can be formed by a sight glass.

Further, flange sealing connections are respectively formed between the valve box main body 11 and the valve base 12 and between the valve base 12 and the detection port 60 of the LNG storage tank, so that sealing rubber strips are arranged between the two connected flanges and connected through the flanges between the valve box main body 11 and the valve base 12, and sealing rubber strips are also arranged between the two connected flanges and connected through the flanges between the valve base 12 and the detection port 60 of the LNG storage tank.

In summary, the operation of the online detection device with the above structure is as follows.

The on-line detection device is used for on-line detection of the temperature of the inner wall of the outer tank 73 in the heat insulation layer settling zone 78 in the LNG storage tank, and sequentially comprises the following steps:

1. building a working platform;

2. fixing a flange at the lower end of the valve base 12 and a flange at the upper end of a detection port 60 on the LNG storage tank, and sealing by using a sealing rubber strip;

3. a sealing rubber strip is arranged at a flange at the upper end of the valve base 12;

4. placing the first rod 21 1.3 meters long inside the valve base 12, and screwing the first connector 231 in the connection node 23 to the upper end of the first rod 21;

5. leading out a thermocouple connecting wire from the lower part of the valve box main body 11, penetrating through a connecting hole on the first connecting piece 231, penetrating into the first rod piece 21 and penetrating out of the lower end of the first rod piece 21, wherein the thermocouple connecting wire is installed in place, and the end part of the thermocouple connecting wire is connected with a temperature measuring probe which is positioned at the lower end of the first rod piece 21;

6. the valve housing main body 11 is lifted up above the valve base 12, and the top of the second rod 22 with the length of 2.2 meters is passed through the valve housing main body 11 and screwed with the second connecting member 232 in the connecting joint 23, thereby completing the connection of the first rod 21, the connecting joint 23 and the second rod 22;

7. fixing a flange at the lower end of the valve box main body 11 and a flange at the upper end of the valve base 12 to complete the connection of the valve box main body 11 and the valve base 12;

8. connecting the gas filling connector 14 with a nitrogen gas source through a high-pressure hose, wherein the nitrogen gas source is fixedly arranged on the tank top of the LNG storage tank; opening a nitrogen valve, inputting nitrogen into the valve box main body 11, observing a pressure gauge 18 at the top of the valve box main body 11, and stopping inputting the nitrogen when the pressure inside the valve box main body 11, which is displayed by the pressure gauge 18, is 1-2 kpa higher than the pressure of the LNG storage tank;

9. the ball valve 61 on the detection port 60 on the LNG storage tank is opened, the ball valve 61 needs to be communicated with a main control room before being opened every time, the internal pressure of the LNG storage tank is known through an interphone, and an operator can control and operate the internal pressure of the valve box main body 11 better;

10. the first rod piece 21, the temperature measuring probe and the thermocouple connecting wire are sent into the LNG storage tank by moving the second rod piece 22, two persons are required to finish the operation synchronously, one person is responsible for moving the second rod piece 22, the other person is responsible for rotating the hand wheel 133, releasing the thermocouple connecting wire wound on the wire spool 132, and the synchronism of the actions of the two persons is observed through the observation port 16;

11. after the second rod member 22 is moved to the right position, the upper end of the second rod member 22 is connected with the third rod member 24 with the length of 1 meter or 1.5 meters in a threaded manner;

12. continuing to move the measuring guide rail 20 until all the rod pieces move in place; at the moment, the first rod piece 21 reaches the annular area and is abutted against the inner part of the outer tank 73, so that the temperature measuring probe is contacted with the inner wall of the outer tank 73 in the annular area, and temperature data are read and recorded according to the temperature instrument 15;

13. the first rod piece 21, the second rod piece 22 and the temperature measuring probe are moved out of the LNG storage tank, two persons are required to synchronously complete the operation, one person is responsible for moving the second rod piece 22, the other person is responsible for rotating the hand wheel 133 and winding the thermocouple connecting wire on the wire spool 132, and the synchronism of actions of the two persons is observed through the observation port 16 and whether the measuring guide rail 20 is completely moved out is judged;

14. after the first rod 21 is completely moved out of the ball valve 61, the ball valve 61 on the detection port 60 on the LNG storage tank is closed, and the nitrogen valve is closed, thereby completing the online internal detection of the inner wall temperature of the inner tank 73 of the LNG storage tank at the insulation layer settling zone 78.

Secondly, the online detection device is used for online detection of the settlement height of the heat-insulating layer 72, and sequentially comprises the following steps:

1. building a working platform;

5. leading out the wear-resistant connecting line from the lower part of the valve box main body 11, penetrating the wear-resistant connecting line through a connecting hole in the first connecting piece 231, penetrating the wear-resistant connecting line into the first rod piece 21, and penetrating the wear-resistant connecting line out of the lower end of the first rod piece 21, wherein the wear-resistant connecting line is installed in place, and the end part of the wear-resistant connecting line is connected with a copper pendant probe which is positioned at the lower end of the first rod piece 21;

10. the first rod piece 21, the copper pendant probe and the wear-resistant connecting wire are sent into the LNG storage tank by moving the second rod piece 22, two persons are required to finish the operation synchronously, one person is responsible for moving the second rod piece 22, the other person is responsible for rotating the hand wheel 133 and releasing the wear-resistant connecting wire wound on the wire spool 132, and the synchronism of actions of the two persons is observed through the observation port 16;

12. continuing to move the measuring guide rail 20 until all the rod pieces move in place; at this time, the first pin 21 reaches into the annular region and abuts against the inside of the outer tank 73, and the measurement direction is determined based on the top mark of the third pin 24;

13. continuing to rotate the hand wheel 133, continuing to release the wear-resistant connecting wire, and observing the state of the spring 134 through the observation port 16 to judge whether the copper pendant probe reaches the position of perlite; when the copper pendant probe is judged to reach the position of the perlite, the hand wheel 133 stops rotating, namely the wear-resistant connecting wire is released;

14. reversely rotating the hand wheel 133, withdrawing the copper pendant probe, and recording the number of rotation turns of the hand wheel 133 in the process;

15. calculating the settlement height of the insulating layer 72 through the number of turns of the hand wheel 133, the structural data of the safety valve box 10, the structural data of the measurement guide rail 20, and the structural data of the LNG storage tank and the detection port 60;

16. the first rod piece 21, the second rod piece 22 and the copper pendant probe are moved out of the LNG storage tank, two persons are required to synchronously complete the operation, one person is responsible for moving the second rod piece 22, the other person is responsible for rotating the hand wheel 133 and winding the wear-resistant connecting wire on the wire spool 132, and the synchronism of actions of the two persons is observed through the observation port 16 and whether the measurement guide rail 20 is completely moved out is judged;

17. after the first rod 21 is completely moved out of the ball valve 61, the ball valve 61 on the detection port 60 on the LNG storage tank is closed, and the nitrogen valve is closed, thereby completing the online internal detection of the sedimentation height of the thermal insulation layer 72 in the LNG storage tank.

In conclusion, the online detection device for LNG storage tank inside heat preservation subsides that this application relates to has realized online internal detection, directly detects out the inner wall temperature of the outer jar 73 of 78 department in heat preservation subsidence area and the settlement height of heat preservation 72, has promoted the efficiency of detection operation's reliability and convenience, detection greatly, and especially, the detection data receives external environment's influence very little, and the detection data accuracy is very high.

Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. The utility model provides a device that is used for inside heat preservation of LNG storage tank to subside on-line measuring which characterized in that: the device comprises a safety valve box (10), a measuring guide rail (20) and a measuring probe (30);

the safety valve box (10) comprises a valve box main body (11), a valve base (12) connected to the lower end of the valve box main body (11) in a sealing mode, and an operation and control assembly (13) installed on the valve box main body (11), wherein the lower end of the valve base (12) is used for being connected with a detection port (60) on an LNG storage tank in a sealing mode, the operation and control assembly (13) is connected with a measuring probe (30) through a connecting line (40), and an inflation interface (14) communicated with the interior of the valve box main body (11) is arranged on the valve box main body (11);

the measurement guide rail (20) comprises a first rod piece (21) which can be placed in the LNG storage tank, a second rod piece (22) which can be vertically moved and is arranged in the valve box main body (11) and the valve base (12) in a penetrating mode, and a connecting joint (23), a sealing piece (50) is arranged between the upper end of the second rod piece (22) and the valve box main body (11), the lower end of the second rod piece (22) is rotatably connected with the upper end of the first rod piece (21) through the connecting joint (23), the measurement probe (30) is connected to the lower end of the first rod piece (21), and the extension direction of the connecting line (40) between the control assembly (13) and the measurement probe (30) is consistent with the extension directions of the first rod piece (21) and the second rod piece (22);

the measuring probe (30) is a temperature measuring probe or a settlement height measuring probe.

2. The apparatus of claim 1, wherein: the connecting joint (23) comprises a first connecting piece (231) fixedly connected to the upper end of the first rod piece (21), a second connecting piece (232) connected to the lower end of the second rod piece (22), a rotating shaft (233) connected with the first connecting piece (231) and the second connecting piece (232) in a rotating mode, and a torsion spring (234) sleeved on the rotating shaft (233), wherein a first limiting portion (235) is arranged on the first connecting piece (231), a second limiting portion (236) is arranged on the second connecting piece (232), the first limiting portion (235) is in butt fit with the second limiting portion (236), one end of the torsion spring (234) is connected with the first connecting piece (231), and acting force for enabling the first limiting portion (235) to face the second limiting portion (236) is applied to the first connecting piece (231).

3. The apparatus of claim 1, wherein: the control assembly (13) comprises a horizontally extending transmission shaft (131), a wire spool (132) fixed on the transmission shaft (131), and a hand wheel (133) fixed at the end of the transmission shaft (131), the transmission shaft (131) is rotatably installed in the valve box main body (11), the wire spool (132) is located inside the valve box main body (11), the connecting wire (40) is wound on the wire spool (132), and the hand wheel (133) is located outside the valve box main body (11).

4. The apparatus of claim 1 or 3, wherein: when the measuring probe (30) is a temperature measuring probe, the connecting wire (40) is a thermocouple connecting wire.

5. The apparatus of claim 4, wherein: install temperature instrument (15) on valve box main part (11), the thermocouple connecting wire links to each other with temperature instrument (15).

6. The apparatus of claim 1 or 5, wherein: when the measuring probe (30) is a probe for measuring the sedimentation height, the connecting wire (40) is a wear-resistant connecting wire.

7. The apparatus of claim 6, wherein: the operating assembly (13) comprises a horizontally extending spring (134), two ends of the spring (134) are connected with the valve box main body (11), and the connecting wire (40) penetrates through the spring (134); the probe for measuring the sedimentation height is a copper pendant probe.

8. The apparatus of claim 1, wherein: the valve box main body (11) is provided with an observation port (16).

9. The apparatus of claim 1, wherein: and the valve box main body (11) is in flange sealing connection with the valve base (12) and the valve base (12) is in flange sealing connection with the detection port (60) of the LNG storage tank.

10. The apparatus of claim 1, wherein: the pressure measuring valve is characterized in that a pressure gauge (18) is installed on the valve box main body (11), and the pressure measuring end of the pressure gauge (18) is located in the valve box main body (11).