An integrated device for visual detection inside LNG storage tanks

Abstract

The present invention relates to an integrated device for visual detection of the inside of an LNG storage tank, which includes a mounting hole reserved on the tank top of the LNG storage tank, a cable device installed on the outside of the tank top of the LNG storage tank, a first end of the cable device arranged in the LNG storage tank through the mounting hole, and a magnetic fixing block arranged at the first end of the cable device, the magnetic fixing block adsorbed on the bottom of the tank body of the LNG storage tank; the second end of the cable device is connected to a power supply and control system arranged outside the LNG storage tank; the cable device is located in the LNG storage tank, and a detection device is arranged on the cable device, and the detection device realizes visual detection of the inside of the LNG storage tank. The present invention can perform three-dimensional laser imaging and visible light imaging of the inside of the storage tank without stopping the vehicle, intuitively observe and monitor the internal conditions of the storage tank, observe the deformation caused by temperature stress in the storage tank, intuitively observe the corrosion conditions inside the storage tank, and observe the amount of ice deposition in the storage tank.

Description

Technical Field

[0001] The invention relates to the technical field of ultra-low temperature medium storage space monitoring, and in particular to an integrated device for visual detection inside an LNG storage tank. Background Art

[0002] LNG (liquefied natural gas) storage tanks are the core facilities for LNG storage and transportation. They have the characteristics of large storage space, low medium temperature, expensive construction, and difficult maintenance. The construction of LNG storage tanks is complex. The inner tank is a large steel storage tank formed by welding special steel plates that are resistant to ultra-low temperatures. In addition, the inner tank also includes facilities and equipment such as unloading pipelines, pump wells, and low-pressure pumps. The working medium of the LNG storage tank is liquefied natural gas stored at normal pressure, and the storage temperature is about -165°C. The materials built at normal temperature will produce temperature shrinkage stress and deformation at ultra-low temperatures. However, there is still no detection technology to monitor whether the deformation of the facilities in the tank during the pre-cooling process exceeds the design parameters, and it is impossible to verify the design and construction parameters. On the other hand, after the tank welds have undergone hydraulic pressure tests and later construction, corrosion is inevitable. After commissioning, it is impossible to conduct regular inspections on the corrosion of the facilities inside the tank. Finally, as pressure vessels in LNG receiving stations, storage tanks should be inspected regularly according to the special equipment inspection standard "TSG R7004 Pressure Vessel Supervision Inspection Rules" to ensure the integrity of the facilities. However, there is currently no effective means to complete online or intermittent monitoring of the interior of LNG storage tanks to ensure the integrity of the facilities.

[0003] At present, there are patent applications for acoustic emission internal detection technology for oil storage tanks, but there is no internal detection technology for LNG storage tanks. Therefore, there is no solution to the above problems. Therefore, it is necessary to further study the internal detection and monitoring equipment, methods and technologies of LNG storage tanks. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide an integrated device for visual detection of the interior of an LNG tank, which can perform three-dimensional laser imaging and visible light imaging of the interior of the tank without stopping the vehicle, visually observe and monitor the internal conditions of the tank, observe the deformation caused by temperature stress in the tank, visually observe the corrosion conditions inside the tank, and observe the amount of ice deposited in the tank.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an integrated device for visual detection of the inside of an LNG storage tank, comprising: an LNG storage tank, a power supply and control system, a cable device, a detection device and a magnetic fixing block; a mounting hole is reserved on the tank top of the LNG storage tank, the cable device is installed on the outside of the tank top of the LNG storage tank, the first end of the cable device is arranged in the LNG storage tank through the mounting hole, and the magnetic fixing block is arranged at the first end of the cable device, and the magnetic fixing block is adsorbed on the bottom of the tank body of the LNG storage tank; the second end of the cable device is connected to the power supply and control system arranged outside the LNG storage tank; the detection device is located in the LNG storage tank, and is arranged on the cable device, and the detection device realizes visual detection of the inside of the LNG storage tank.

[0006] Furthermore, the cable device includes a power supply and signal cable, a steel strand cable and a cable shaft; one end of the power supply and signal cable is connected to the detection device, and the other end is connected to the power supply and control system via the cable shaft; the first end of the steel strand cable is connected to the magnetic fixing block, and the second end of the steel strand cable is connected to the cable shaft arranged on the outside of the LNG tank top through the mounting hole.

[0007] Furthermore, the power supply and signal cable includes a cable shell, a cold insulation layer, a signal cable and a power supply cable; the cold insulation layer is provided on the inner side of the cable shell, and the signal cable and the power supply cable are located inside the cold insulation layer; the signal cable and the power supply cable are connected to the detection device to power the detection device, and transmit the signal detected by the detection device to the power supply and control system via the signal cable.

[0008] Furthermore, the detection device includes a sealed shell and a back hole, and a mounting base, a camera device, a laser imaging device and a lighting device arranged in the sealed shell; the camera device, the laser imaging device and the lighting device are arranged on the mounting base through a rotating shaft, and the rotating shaft is driven to rotate by a motor arranged in the sealed shell, and the motor is connected to the power supply and control system via the power supply and signal cable; the back hole is arranged on the back of the sealed shell, and the first end of the steel strand cable passes through the back hole and is connected to the magnetic fixing block; the power supply and signal cable passes through the sealed shell and is connected to the camera device, the laser imaging device and the lighting device to supply power to each component, and the image signal collected by the camera device and the laser imaging device is transmitted to the power supply and control system via the signal cable.

[0009] Furthermore, the lighting equipment adopts LED lighting facilities, and the color temperature of the light source is 3000K or 6000K; the rated service life of the lighting facilities should be greater than or equal to 5000 hours; the brightness of the lighting facilities should be continuously adjustable; and the central illumination should be greater than or equal to 33000lx.

[0010] Furthermore, the resolution of the camera device is greater than or equal to 2 million pixels; the sensitivity is not less than 0.21ux@f1.4; the focus mode is automatic focus or manual focus; the magnification range is not less than 30:1, and the magnification mode is manual or electric; the camera device can withstand an external air pressure of not less than 50 bar.

[0011] Furthermore, the laser imaging device can generate three-dimensional imaging of the space inside the tank, using a parallax scanning method at a close distance and a laser phase scanning method at a long distance.

[0012] Furthermore, the sealed shell is a sealed cavity made of a transparent material such as special glass or special resin material, and the sealed cavity is in a vacuum state.

[0013] Furthermore, the special glass or special resin is an ultra-low temperature material that can withstand temperatures below -165°C.

[0014] Furthermore, the power supply and control system includes mobile power supply facilities and an industrial control computer; the power supply facilities are used to supply power to the industrial control computer and the detection device; the industrial control computer controls the detection device deep inside the LNG storage tank to achieve depth position control, detector opening and closing control, imaging parameter control, size measurement control, temperature distribution imaging control, leakage alarm control, data processing and storage control.

[0015] Due to the adoption of the above technical scheme, the present invention has the following advantages: 1. The present invention is used for visualization imaging, internal dimension measurement, internal equipment and facility corrosion status / weld status / defect / crack and structural deformation observation, leakage monitoring, temperature distribution observation of the sealed cavity that conventional observation devices cannot enter, such as the interior of the LNG storage tank or the storage tank of the LNG transport ship, and can also detect the precipitation of ice inside the LNG storage tank or the transport ship. The present invention can realize imaging and detection inside the closed space, and transmit the detection data to the control system outside the closed space through a cable for processing and analysis. 2. The present invention can observe and understand the corrosion status, weld status, leakage, and bottom ice precipitation of the inner wall of the LNG storage tank, the inner wall of the LNG transport ship, and the facilities inside the tank and the cabin through the detection data. 3. The present invention can perform three-dimensional laser imaging and visible light imaging on the inside of the storage tank without stopping, intuitively observe and monitor the internal situation of the storage tank, observe the deformation caused by temperature stress in the storage tank, intuitively observe the corrosion status inside the storage tank, and observe the amount of ice precipitation in the storage tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0017] Figure 2 This is a front view of the detection device.

[0018] Figure 3 It is a side view of the detection device.

[0019] Figure 4 This is a cross-sectional view of the power supply and signal cables.

[0020] Figure numbers: 1. LNG storage tank, 2. Power supply and control system, 3. Cable device, 4. Detection device sealing device, 5. Magnetic fixing block, 6. Camera equipment, 7. Laser imaging equipment, 8. Lighting equipment, 9. Sealing device back hole, 10. Power supply and signal cables, 11. Cable casing, 12. Cold insulation layer, 13. Signal cable, 14. Power supply cable. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0022] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] like Figure 1 to Figure 4 As shown, the present invention provides an integrated device for visual detection inside an LNG storage tank, which includes an LNG storage tank 1, a power supply and control system 2, a cable device 3, a detection device 4 and a magnetic fixing block 5.

[0024] The top of the LNG storage tank 1 is provided with a mounting hole, and the cable device 3 is installed outside the top of the LNG storage tank 1. The first end of the cable device 3 is arranged in the LNG storage tank 1 through the mounting hole, and a magnetic fixing block 5 is arranged at the first end of the cable device 3, and the magnetic fixing block 5 is adsorbed on the bottom of the tank body of the LNG storage tank 1; the second end of the cable device 3 is connected to the power supply and control system 2 arranged outside the LNG storage tank 1. Located in the LNG storage tank 1, a detection device 4 is arranged on the cable device 3, and the detection device 4 realizes visual detection inside the LNG storage tank.

[0025] In the above embodiment, the cable device 3 includes a power supply and signal cable 10, a steel strand cable and a cable shaft. One end of the power supply and signal cable 10 is connected to the detection device 4, and the other end is connected to the power supply and control system 2 via the cable shaft. The first end of the steel strand cable is connected to the magnetic fixing block 5, and the second end of the steel strand cable is connected to the cable shaft arranged outside the LNG tank top through the reserved mounting hole on the LNG tank top.

[0026] Among them, Figure 4 As shown, the power supply and signal cable 10 includes a cable housing 11, a cold insulation layer 12, a signal cable 13 and a power supply cable 14. The cold insulation layer 12 is provided inside the cable housing 11, and the signal cable 13 and the power supply cable 14 are located inside the cold insulation layer 12; and the signal cable 13 and the power supply cable 14 are connected to the detection device 4, for supplying power to the detection device 4, and transmitting the signal detected by the detection device 4 to the power supply and control system 2 via the signal cable 13.

[0027] Preferably, the steel strand cable uses φ25 stainless steel strand.

[0028] In the above embodiment, Figure 2 , Figure 3 As shown, the detection device 4 includes a sealed shell and a back hole 9, as well as a mounting seat, a camera device 6, a laser imaging device 7 and a lighting device 8 arranged in the sealed shell. The camera device 6, the laser imaging device 7 and the lighting device 8 are arranged on the mounting seat through a rotating shaft, and the rotating shaft is driven to rotate by a motor arranged in the sealed shell, and the motor is connected to the power supply and control system 2 through a power supply and signal cable 10. The power supply and control system 2 controls the motor movement, thereby driving the rotating shaft to rotate in the horizontal direction to control the shooting angle of the camera device 6 and the laser imaging device 7 (from 45° to -315°), and the circumferential detection is achieved by controlling the horizontal rotation of the detection device 4. The back hole 9 is arranged at the back of the sealed shell, and the first end of the steel strand cable passes through the back hole 9 and is connected to the magnetic fixing block 5. The steel strand cable prevents the detection device 4 from flowing with the LNG in the tank, and ensures the vertical direction of the detection device 4.

[0029] Among them, the power supply and signal cable 10 passes through the sealed shell and is connected to the camera device 6, the laser imaging device 7 and the lighting device 8 to provide power to each component; the image signal collected by the camera device 6 and the laser imaging device 7 is transmitted to the power supply and control system 2 via the signal cable 13.

[0030] Preferably, the lighting device 8 can be an LED lighting facility with a light source color temperature of 3000K or 6000K. The rated service life of the lighting facility should be greater than or equal to 5000 hours; the brightness of the lighting facility should be continuously adjustable; the central illumination should be greater than or equal to 33000lx; and the maximum downward extension depth should be greater than or equal to 10 meters.

[0031] Preferably, the resolution of the camera device 6 is greater than or equal to 2 million pixels; the sensitivity is not less than 0.21ux@f1.4; the focusing mode of the camera device 6 can be automatic focus or manual focus; the magnification range is not less than 30:1, and the magnification mode can be manual or electric; the camera device 6 can withstand an external air pressure of not less than 50 bar.

[0032] Preferably, the laser imaging device 7 can generate three-dimensional imaging of the space inside the storage tank, using parallax scanning at close distances and laser phase scanning at long distances; the parallax scanning method measures a target size of not less than 4 meters, with a measurement accuracy of not less than 0.2mm; the phase scanning method measures a distance of not less than 30 meters, with a measurement accuracy of not more than ±3mm.

[0033] Preferably, the sealed housing is a sealed cavity made of a transparent material such as special glass or special resin material, and the sealed cavity is in a vacuum state. The special glass or special resin is an ultra-low temperature material that can withstand temperatures below -165°C.

[0034] In the above embodiments, the power supply and control system 2 includes a mobile power supply facility and an industrial computer. The power supply facility is used to supply power to the industrial computer and the detection device 4. The industrial computer is used to control the detection device 4 deep inside the LNG storage tank, realize depth position control, detector opening and closing control, imaging parameter control, size measurement control, temperature distribution imaging control, leakage alarm control, data processing and storage control, etc., and can also realize the maintenance of the entire system. Among them, the depth position control refers to the transmission of the position information received by the laser device to the control system outside the tank through the cable, and the control system controls the lowering depth of the device through the cable device.

[0035] In the above embodiments, the magnetic fixing block 5 is a magnetic block with a mass of not less than 25 kg.

[0036] In the above embodiments, a signal interface may be further provided on the sealed housing for signal communication between the detection device 4 and an external device.

[0037] In summary, when the present invention is in use, first pass the φ25 stainless steel strand through the back hole 9 of the detection device 4 to connect the magnetic fixing block 5, which weighs 25kg. Use the steel strand cable shaft to slowly lower the magnetic fixing block 5 through the 8-inch reserved mounting hole on the top of the LNG tank to the bottom of the storage tank, and tighten the steel strand after the magnetic adsorption is completed. Slowly lower the detection device 4 into the tank through the reserved hole on the top of the tank, control the lowering depth through the power supply and signal cable 10, and control it to be lowered in the vertical direction through the steel strand. The shooting angle (from 45° to -315°) is controlled by controlling the rotation axis of the detection device, and circumferential detection is achieved by controlling the detection device 4 and horizontal rotation.

[0038] Example:

[0039] like Figure 1 As shown, the lighting equipment 8 included in the detection device 4 adopts LED lighting facilities, the color temperature of the lighting facilities is 5000K, the effective range of visible light reaches 80 meters, the resolution of the visible light device is 8 million pixels, the device zooms 80 times, the zoom mode is automatic, and the device withstands a pressure of 50bar. The detection device 4 also includes a phase scanning laser imaging device, which can generate three-dimensional imaging of the space in the storage tank, with a measuring distance of 80 meters and a measuring accuracy of 3mm. The sealed shell of the detection device 4 is made of epoxy transparent resin. The sealed shell is vacuumed and insulated. Signal communication is carried out between the power supply and control system 2 and the detection device 2 through cables and MODBUS485 interfaces. The power supply and control system 2 can realize the operation of taking photos, video recording, three-dimensional imaging, signal processing and recording of the probe device.

[0040] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principle and essence of the present invention, but these changes and modifications shall fall within the scope of protection of the present invention.

Claims

1. An integrated device for visual detection inside an LNG tank, characterized in that: include: LNG storage tanks, power supply and control systems, cable devices, detection devices and magnetic fixing blocks; The tank top of the LNG storage tank is reserved with a mounting hole, the cable device is installed on the outside of the tank top of the LNG storage tank, the first end of the cable device is arranged in the LNG storage tank through the mounting hole, and the magnetic fixing block is arranged at the first end of the cable device, and the magnetic fixing block is adsorbed on the bottom of the tank body of the LNG storage tank; the second end of the cable device is connected to the power supply and control system arranged outside the LNG storage tank; the detection device is arranged on the cable device located in the LNG storage tank, and the detection device realizes visual detection inside the LNG storage tank; The cable device includes a power supply and signal cable, a steel strand cable and a cable shaft; one end of the power supply and signal cable is connected to the detection device, and the other end is connected to the power supply and control system via the cable shaft; the first end of the steel strand cable is connected to the magnetic fixing block, and the second end of the steel strand cable is connected to the cable shaft arranged outside the tank top of the LNG storage tank through the mounting hole; the steel strand cable adopts φ25 stainless steel strand; The power supply and signal cable comprises a cable housing, a cold insulation layer, a signal cable and a power supply cable; The cold insulation layer is provided on the inner side of the cable housing, and the signal cable and the power supply cable are located in the cold insulation layer; the signal cable and the power supply cable are connected to the detection device to supply power to the detection device, and transmit the signal detected by the detection device to the power supply and control system via the signal cable; The detection device includes a sealed shell and a back hole, as well as a mounting seat, a camera device, a laser imaging device and a lighting device arranged in the sealed shell; the camera device, the laser imaging device and the lighting device are arranged on the mounting seat through a rotating shaft, and the rotating shaft is driven to rotate by a motor arranged in the sealed shell, and the motor is connected to the power supply and control system through the power supply and signal cable; the back hole is arranged at the back of the sealed shell, and the first end of the steel strand cable passes through the back hole and is connected to the magnetic fixing block; the power supply and signal cable passes through the sealed shell and is connected to the camera device, the laser imaging device and the lighting device to supply power to each component, and the image signal collected by the camera device and the laser imaging device is transmitted to the power supply and control system through the signal cable; The sealed housing is a sealed cavity made of a transparent material such as special glass or special resin material, and the sealed cavity is in a vacuum state; The power supply and control system includes mobile power supply facilities and an industrial control computer; the power supply facilities are used to power the industrial control computer and the detection device; the industrial control computer controls the detection device deep inside the LNG storage tank to achieve depth position control, detector opening and closing control, imaging parameter control, size measurement control, temperature distribution imaging control, leakage alarm control, data processing and storage control.

2. The integrated device for visual detection of the interior of an LNG storage tank as claimed in claim 1, characterized in that: The lighting equipment adopts LED lighting facilities, and the color temperature of the light source is 3000K or 6000K; the rated service life of the lighting facilities should be greater than or equal to 5000 hours; the brightness of the lighting facilities should be continuously adjustable; the central illumination should be greater than or equal to 33000lx.

3. The integrated device for visual detection of the interior of an LNG storage tank as claimed in claim 1, characterized in that: The resolution of the camera device is greater than or equal to 2 million pixels; the sensitivity is not less than 0.21ux@f1.4; the focus mode is automatic focus or manual focus; the magnification range is not less than 30:1, and the magnification mode is manual or electric; the camera device can withstand an external air pressure of not less than 50 bar.

4. The integrated device for visual detection of the interior of an LNG storage tank as claimed in claim 1, characterized in that: The laser imaging device can generate three-dimensional imaging of the space inside the tank, using a parallax scanning method at a close distance and a laser phase scanning method at a long distance.

5. The integrated device for visual detection of the interior of an LNG storage tank as claimed in claim 1, characterized in that: The special glass or special resin material is an ultra-low temperature material that can withstand temperatures below -165°C.

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