Intelligent automatic overhauling device and overhauling method for double ball valves of LNG unloading arm

Abstract

The invention discloses an intelligent automatic overhauling device and method for double ball valves of an LNG unloading arm. Self-locking hoisting devices are arranged at the four corners of an overhauling platform, and honeycomb-shaped reinforcing ribs are welded to the lower surface of the overhauling platform. The double-ball-valve overhauling device comprises two vertical supporting columns and a first platform, the first platform is provided with C-shaped hydraulic clamps which are distributed orthogonally, and self-adaptive clamping is achieved through an infrared positioning module and a hydraulic driving device. The rotary joint maintenance device adopts three support columns distributed in an equilateral triangle to support an annular second platform, airtight test holes are uniformly distributed in the circumferential direction of the platform, and wireless pressure sensors are embedded in the holes. The intelligent cooperation device is integrated with a vibration monitoring module, an AR auxiliary module and an alarm module, the AR auxiliary module collects three-dimensional point cloud through an industrial camera, a CAD model is matched through an edge calculation unit, and virtual disassembly guidance and a leakage thermodynamic diagram are overlaid on AR glasses. According to the device, collaborative operation of multi-directional precise disassembly and assembly of the double-ball valve and full-circumference sealing detection of the rotary joint is achieved, and the maintenance efficiency and safety are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of unloading arm maintenance, and in particular to an intelligent automatic maintenance device and maintenance method for a double ball valve of an LNG unloading arm. Background Art

[0002] In the fields of liquefied natural gas, chemicals, etc., the unloading arm is a key conveying equipment. The reliability and maintenance efficiency of its double ball valve and rotary joint directly affect the safety and cost of the operation. Due to the complex structure and variable installation direction of the double ball valve, traditional maintenance devices often use fixed clamps or temporary support structures, which are difficult to adapt to the disassembly and assembly requirements of valves of different sizes and spatial angles, resulting in cumbersome operations and easy to cause secondary damage to the components. The airtightness test of the rotary joint needs to cover multiple circumferential directions, but conventional testing platforms mostly rely on single-point or local testing, which makes it difficult to achieve evenly distributed pressure injection points, easily resulting in missed leaks and affecting maintenance accuracy.

[0003] Most existing maintenance devices adopt a split design, and the maintenance areas of the double ball valve and the rotary joint are independent of each other, resulting in a fragmented working space and duplicate equipment configuration. The structural design of the existing maintenance platform has systemic defects: first, the load-bearing frame lacks overall mechanical optimization, and is prone to deformation due to stress concentration during lifting and displacement, affecting the accuracy of the maintenance reference surface; second, the clamp has a single function and cannot dynamically adjust the clamping force according to the valve size and installation direction, and the operation relies on manual experience; third, the lack of a safety monitoring mechanism means that abnormal vibrations or load offsets during the disassembly and assembly of heavy components cannot be warned in real time. The above limitations lead to low maintenance efficiency, unstable maintenance quality, and are prone to induce safety accidents in high-risk working environments. An integrated and intelligent solution is urgently needed. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides an intelligent automatic maintenance device for double ball valves of LNG unloading arm, comprising: a maintenance platform with self-locking lifting devices at the four corners; A double ball valve maintenance device is provided on one side of the maintenance platform, comprising two vertically mounted double ball valve maintenance support columns, the upper ends of which are connected to a first platform, the long sides of which are parallel to the side edges of the maintenance platform; A double ball valve fixing device is provided on the first platform, and the double ball valve fixing device includes a first ball valve fixing device and a second ball valve fixing device; A rotary joint maintenance device is provided on the other side of the maintenance platform, comprising three vertically mounted rotary joint maintenance support columns, wherein the distance between each of the three rotary joint maintenance support columns and the orthographic projections of the other two rotary joint maintenance support columns on the maintenance platform is equal, and the upper ends of the rotary joint maintenance support columns are connected to an annular second platform, and the second platform is provided with a plurality of equally spaced airtight test devices along the circumference; The intelligent collaborative device includes a vibration monitoring module, an AR auxiliary module, and an alarm module, which are electrically connected to the main control module respectively. Furthermore, the AR auxiliary module includes: The industrial camera is installed above the maintenance platform. The checkerboard method is used to determine the industrial camera-mechanical coordinate system conversion matrix. It is used to collect the 3D point cloud data of the double ball valve in real time and transmit the RGB image and 3D point cloud data to the edge computing unit. The edge computing unit is used to run the deep learning model, input the image to the YOLOv7 segmentation network, identify the double ball valve in real time, output the component type and bounding box, align the recognition result with the model in the knowledge base through the spatial matching engine, and output the 3D matrix to the AR glasses; Incremental knowledge base, used to update and store models, disassembly and assembly procedures, and torque parameters of double ball valves and rotary joints; AR glasses are used to provide virtual guidance in the maintenance personnel's field of view and superimpose virtual outlines on the real double ball valve.

[0005] Furthermore, the double ball valve maintenance support column is fixedly connected to the maintenance platform by bolts, and the axis of the double ball valve maintenance support column is perpendicular to the upper surface of the maintenance platform, the double ball valve fixing device is a C-shaped ring opening, the first ball valve fixing device is connected to the first platform through a first connecting seat, and the second ball valve fixing device is connected to the first platform through a second connecting seat, and the height of the second connecting seat is greater than the height of the first connecting seat; the arc cross-section of the first ball valve fixing device is parallel to the long side of the first platform, and the arc cross-section of the second ball valve fixing device is perpendicular to the long side of the first platform.

[0006] Furthermore, the first connecting seat and the second connecting seat are both adjustable lifting structures, and the adjustable lifting structure is a lifting sleeve. The outer wall of the lifting sleeve is provided with axial scale lines, and the interior of the lifting sleeve is provided with a hydraulic locking mechanism, which is electrically connected to the vibration monitoring module.

[0007] Furthermore, the double-ball valve fixing device is a hydraulically driven adaptive clamp, and the hydraulic driving device is arranged inside the first connecting seat and the second connecting seat. An infrared positioning module and a pressure sensor are provided on the inner side of the C-shaped ring opening of the double-ball valve fixing device. The infrared positioning module and the pressure sensor are electrically connected to the main control module, and the main control module is electrically connected to the hydraulic driving device.

[0008] Furthermore, the airtight test device is an airtight test hole, the spacing between the airtight test holes is 1 / 12 to 1 / 8 of the circumference of the second platform, and each airtight test hole is embedded with a wireless pressure sensor and a sealing rubber ring, and the wireless pressure sensor is electrically connected to the master control module.

[0009] Furthermore, the vibration monitoring module is arranged on the double ball valve maintenance support column and the rotary joint maintenance support column and is connected to the sound and light display device, and the alarm module is arranged below the double ball valve fixing device.

[0010] Furthermore, a fixed anchor point is provided on the maintenance platform, which is arranged at the side of the maintenance platform between the double ball valve maintenance device and the rotary joint maintenance device, and is used to fix external equipment. The fixed anchor point is provided with a hydraulic quick connector for one-click locking of external clamps. The fixed anchor point includes an ear plate vertically arranged on the side of the maintenance platform, and the ear plate is provided with a through bolt hole for connecting external clamps.

[0011] Furthermore, the lower surface of the maintenance platform is provided with a plurality of reinforcing ribs, which are distributed in a honeycomb shape and are welded and fixed to the bottom of the double ball valve maintenance support column and the rotary joint maintenance support column. The lifting device is a lifting ear, which is a U-shaped structure and is welded to the four corner edges of the maintenance platform, and the inner side of the lifting ear is provided with anti-slip grooves.

[0012] A maintenance method for an intelligent automatic maintenance device for a double ball valve of an LNG unloading arm is applied to the intelligent automatic maintenance device for a double ball valve of an LNG unloading arm according to any one of claims 1 to 9, and is characterized by comprising the following steps: S1. The maintenance platform is hoisted to the work area using the four-corner self-locking hoisting device. The hoisting device automatically triggers locking when it is subjected to force. The master control module, vibration monitoring module, and alarm module are activated, and the AR auxiliary module is initialized. The industrial camera scans the work environment, and hand-eye calibration is completed using the checkerboard method. The edge computing unit loads the double-ball valve model into the incremental knowledge base. S2. Use the threaded bushings at the fixed anchor points to install external auxiliary equipment, place the discharge arm double ball valve on the first platform, and fix the first ball valve fixing device and the second ball valve fixing device to the ball valves of the discharge arm double ball valve respectively and clamp them through the hydraulic drive device; S3. Adjust the height of the first connecting seat and the second connecting seat according to the axial scale line of the lifting sleeve, and the vibration monitoring module monitors the status of the hydraulic locking mechanism in real time; S4. After the rotary joint flange of the double ball valve of the discharge arm contacts the annular surface of the second platform, the AR glasses in the AR auxiliary module are superimposed with the proposed number to each airtight test hole, and a closed cavity is formed through the airtight test device. The external pressure detection equipment injects the detection medium into the adjacent airtight test devices in sections in sequence. After each test is completed, the joint is rotated circumferentially to the corresponding position of the next set of airtight test devices, and the pressurization operation is repeated until all circumferential tests are covered; the wireless pressure sensor monitors the pressure decay, and performs step-by-step pressurization retests on the points with the largest pressure drop, and generates a leakage heat map and transmits it to the main control module; the edge computing unit compares historical data, marks abnormal intervals, and displays the leakage points in the AR glasses; S5: The disassembly and assembly of the double ball valves in the discharge arm and the inspection of the rotary joint flange can be performed simultaneously. AR glasses superimpose virtual disassembly and assembly instructions. The welded frame of the reinforcement ribs and support columns under the platform distributes the load. External equipment forms a reaction force support with the platform through fixed anchor points. S6. After the maintenance is completed, the hydraulic drive device releases the C-shaped annular opening, releases the clamping of the first ball valve fixing device, the second ball valve fixing device and the double ball valve of the unloading arm, resets the lifting sleeve to the initial height, releases the connection between the rotary joint flange and the airtightness test device on the annular surface of the second platform, releases the mechanical lock of the self-locking lifting device, and transfers the maintenance platform through the lifting device.

[0013] The beneficial effects of the present invention are: The maintenance device of the present invention integrates the valve disassembly and assembly and seal detection functions into the same maintenance platform through the integrated layout of the double ball valve maintenance device and the rotary joint maintenance device. Through the orthogonal distribution of the C-shaped clamp structure, combined with the height-adjustable connecting seat design, it effectively adapts to the disassembly and assembly requirements of the double ball valve in the horizontal and vertical installation directions. The built-in rubber buffer layer of the C-shaped open ring clamp compensates for the flange size tolerance, and the closed-loop control of the infrared positioning module and the hydraulic drive device realizes precise adjustment of the clamping force, avoiding damage to the sealing surface caused by overload of traditional mechanical clamps. The overall frame formed by welding the honeycomb reinforcement ribs and the support columns significantly improves the torsional stiffness of the platform, and cooperates with the rotary joint support columns distributed in an equilateral triangle to disperse the composite load during the operation of heavy components, solving the deformation misalignment problem caused by stress concentration in traditional split platforms.

[0014] The circumferentially distributed airtightness test holes on the annular second platform work in conjunction with the indexing plate's stepping rotation mechanism to achieve 360° continuous segmented seal testing of the rotary joint. A wireless pressure sensor generates a real-time leak heat map. Combined with the AR-assisted module's spatial registration technology, it overlays virtual leak point annotations within the operator's field of view, eliminating the risk of missed detection in blind spots associated with single-point static testing. The vibration monitoring module's linked control of the hydraulic clamping force triggers an audible and visual alarm and automatically locks the lifting mechanism in the event of abnormal load offsets, creating a fully intelligent, collaborative system encompassing component positioning, operation guidance, and safety protection, significantly reducing the rate of maintenance accidents in high-risk environments.

[0015] The maintenance platform's integral frame, formed by welding ribs to support columns, is reinforced by anti-slip grooves on the four corner lifting devices and threaded bushings at the side anchor points, enhancing the platform's resistance to deformation. Optimized mechanical transmission within the lifting, support, and anchoring modules ensures the platform maintains structural rigidity even when carrying heavy components. This provides a stable attachment base for external equipment, reducing the risk of positioning errors caused by platform drift during maintenance operations and improving operational safety and maintenance accuracy in complex working conditions.

[0016] Through the collaborative mechanism of AR real-time guidance, hydraulic adaptive closed loop and intelligent step-by-step detection, precise automation and intelligent operation of LNG heavy valve maintenance can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a top view of an intelligent automated maintenance device for double ball valves in an LNG unloading arm; Figure 2 This is the main view of an intelligent automatic maintenance device for double ball valves in an LNG unloading arm; Figure 3 This is a left view of an intelligent automatic maintenance device for double ball valves in an LNG unloading arm; Figure 4 The figure is a flow chart of an automated maintenance method for a double ball valve of an LNG unloading arm.

[0018] Among them, 1. Maintenance platform; 2. Double ball valve maintenance support column; 3. First platform; 4. First ball valve fixing device; 5. Second ball valve fixing device; 6. Rotary joint maintenance support column; 7. Second platform; 8. Airtightness testing device; 9. First connecting seat; 10. Second connecting seat; 11. Lifting device; 12. Fixed anchor point; 13. Vibration monitoring module. DETAILED DESCRIPTION

[0019] The following is combined with Figure 1-4 The preferred embodiments of the present invention are described in detail so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0020] By arranging a coordinated layout of a double-ball valve maintenance device and a rotary joint maintenance device, maintenance platform 1 integrates double-ball valve assembly and disassembly and rotary joint inspection functions on the same work surface. The double-ball valve maintenance support column 2 is vertically fixed to one side of maintenance platform 1, with the long side of the first platform 3 at its top parallel to the side of maintenance platform 1. This ensures that the C-shaped opening of the first ball valve fixture 4 forms a spatially orthogonal distribution with the second ball valve fixture 5, adapting to the valve installation postures for horizontal and vertical pipes, respectively. The sleeve-type lifting column of the second ball valve fixture 5 is height-adjustable via axial scale lines and a locking nut. Combined with the fixed base of the first connecting seat 9, this forms an adaptive double-ball valve clamping structure for different flange spacings, addressing the technical limitation of traditional clamps that are incompatible with multi-directional installation. A pressure drive device, built into the connecting seat, drives the C-shaped clamping arm to open and close. An infrared positioning module inside the clamping arm scans the flange center coordinates, and a pressure sensor provides real-time feedback of clamping force data to the master control module.

[0021] The rotary joint maintenance support columns 6 are distributed in an equilateral triangle projection. The three support columns are designed to coincide with the axis of the annular second platform 7, so that the platform maintains torque balance when bearing the radial load of the rotary joint. The airtightness test devices 8, i.e., the airtightness test holes, uniformly distributed around the circumference of the second platform 7 are arranged in a radial direction from the center of the circle. A fluororubber sealing ring is embedded in the test hole to form a compression contact surface. The outer edge of the sealing ring protrudes from the platform surface to form a compression contact surface. A wireless pressure sensor is integrated at the bottom of the hole. When the rotary joint flange is aligned and pressed against the test hole, the external air pressure equipment can inject the test medium at different angles to achieve a 360° continuous segmented pressure test of the sealing surface, eliminating the blind spots of traditional single-point detection.

[0022] The radial reinforcement ribs on the lower surface of the maintenance platform 1 are welded to the bottom of the support column to form an overall frame. The anti-slip grooves of the four-corner U-shaped lifting devices 11 are arranged perpendicular to the edge of the platform. Combined with the triangular reinforcement ribs and threaded bushing structure of the side ear plate anchoring points, a multi-level fixing system is constructed. The U-shaped lifting ears are welded vertically on the four corner edges as self-locking lifting devices 11, and the inside of the lifting ears are processed with anti-slip grooves to increase the friction of the lifting rope. Honeycomb reinforcement ribs are welded on the lower surface of the platform. The reinforcement ribs are distributed in a hexagonal grid, extending from the center of the platform to the edge, and are fixed to the bottom of the double ball valve maintenance support column 2 and the rotary joint maintenance support column 6 by continuous fillet welds to form an overall load-bearing frame. This design maintains the structural rigidity of the platform during lifting and displacement by optimizing the mechanical transmission paths of the lifting, support and anchoring modules, while providing a stable locking interface for external equipment to avoid the risk of platform deformation during heavy component maintenance.

[0023] In the intelligent collaborative device, the industrial camera is adsorbed on the maintenance platform 1 through a universal magnetic base, with the lens axis facing the double-ball valve operating area. The camera is connected to the edge computing unit through a USB3.0 interface. The unit has a built-in GPU accelerator card and an incremental knowledge base. The AR glasses communicate with the edge computing unit through the WiFi6 protocol, and the lenses project virtual disassembly and assembly instructions to the operating field of view. The piezoelectric sensor of the vibration monitoring module is embedded in the surface of the support column and connected to the main control module through the CAN bus; the sound and light alarm module is provided at the base below the double-ball valve fixing device. The double-ball valve maintenance device is arranged on one side of the maintenance platform 1, and includes two vertically mounted double-ball valve maintenance support columns 2. The upper end of the double-ball valve maintenance support column 2 is connected to the first platform 3, and the long side of the first platform 3 is parallel to the side of the maintenance platform 1; A double ball valve fixing device is provided on the first platform 3, and the double ball valve fixing device includes a first ball valve fixing device 4 and a second ball valve fixing device 5; the double ball valve maintenance device includes two vertical support columns and the first platform 3. The first platform 3 fixes two ball valve fixing devices in different directions (parallel and vertical to the long side) to meet the multi-angle maintenance needs of the ball valve. The rotary joint inspection device, located on the other side of the inspection platform 1, includes three vertically mounted rotary joint inspection support columns 6. Each of these columns is equidistant from the orthographic projections of the other two columns on the inspection platform 1. The upper ends of these columns are connected to an annular second platform 7, which is circumferentially provided with multiple equally spaced airtightness test holes. The rotary joint inspection device utilizes three equally spaced support columns (their orthographic projections form an equilateral triangle) to support the annular second platform 7. The airtightness test holes are evenly distributed around the circumference, ensuring multi-angle sealing testing of the rotary joint. The double ball valve maintenance support column 2 is fixedly connected to the maintenance platform 1 by bolts, and the axis of the double ball valve maintenance support column 2 is perpendicular to the upper surface of the maintenance platform 1.

[0024] The double ball valve fixing device is an incomplete ring. The first ball valve fixing device 4 is connected to the first platform 3 through the first connecting seat 9, and the second ball valve fixing device 5 is connected to the first platform 3 through the second connecting seat 10. The height of the second connecting seat 10 is greater than the height of the first connecting seat 9; the arc-shaped cross-section of the first ball valve fixing device 4 is parallel to the long side of the first platform 3, and the arc-shaped cross-section of the second ball valve fixing device 5 is perpendicular to the long side of the first platform 3.

[0025] The first connecting seat 9 and the second connecting seat 10 are both adjustable lifting structures for adapting to double ball valves of different sizes.

[0026] The spacing between the airtight test holes is 1 / 12 to 1 / 8 of the circumference of the second platform 7, and a sealing rubber ring is embedded in each airtight test hole.

[0027] The lifting device 11 is a lifting lug, which is a U-shaped structure and is welded to the four corner edges of the maintenance platform 1. The inner side of the lifting lug is provided with anti-slip grooves.

[0028] The maintenance platform 1 is also provided with a fixed anchor point 12, which is set at the side of the maintenance platform 1 between the double ball valve maintenance device and the rotary joint maintenance device, and is used to fix external equipment.

[0029] The fixed anchor point 12 comprises an ear plate vertically welded to the side of the maintenance platform 1 , and a through bolt hole is provided on the ear plate for connecting an external clamp.

[0030] The lower surface of the maintenance platform 1 is provided with a plurality of reinforcing ribs, which are distributed radially and are welded and fixed to the bottom of the double ball valve maintenance support column 2 and the rotary joint maintenance support column 6.

[0031] The lifting device 11 is a U-shaped welded lifting lug with anti-slip grooves on the inside to prevent it from falling off during lifting; the radial reinforcement ribs under the maintenance platform 1 enhance the load-bearing capacity.

[0032] The double ball valve fixing device adapts to valves of different sizes through a height-adjustable connection seat (such as a hydraulic lifting structure), and the difference in the direction of the arc section facilitates the fixing of horizontal / vertical pipeline valves.

[0033] The spacing between the airtight test holes of the annular second platform 7 is 1 / 12 (30° interval) to 1 / 8 (45° interval) of the circumference, and an oil-resistant rubber sealing ring is embedded in it. The test is carried out hole by hole through an external air pressure pump.

[0034] There are four U-shaped lifting devices 11 symmetrically distributed at the four corner edges of the maintenance platform 1. The lifting devices 11 are fixedly connected to the upper surface of the maintenance platform 1 by welding. The opening direction of the lifting device 11 is perpendicular to the edge of the platform, and its inner surface is processed with anti-slip grooves to increase the friction of the sling. The lower surface of the maintenance platform 1 is provided with a radially distributed reinforcement structure. The reinforcement extends from the center of the platform to the edge and is connected to the bottom of the double ball valve maintenance support column 2 and the rotary joint maintenance support column 6 by continuous corner welds to form an integral load-bearing frame. The double ball valve maintenance support column 2 adopts a rectangular cross-section steel column, the lower end of which is fastened to the upper surface of the maintenance platform 1 by a bolt assembly. The axis of the bolt assembly coincides with the axis of the support column. The top of the support column is bolted to the lower surface of the first platform 3 by a flange, so that the long side of the first platform 3 maintains a parallel distance from the side of the maintenance platform 1.

[0035] The double ball valve fixture on the upper surface of the first platform 3 includes a first ball valve fixture 4 and a second ball valve fixture 5. Both are C-shaped ring-shaped openings with a rubber cushioning layer on their inner arc surfaces. The first ball valve fixture 4 is vertically mounted on the upper surface of the first platform 3 via a first connecting seat 9. The first connecting seat 9 is a rectangular base, its bottom secured to the platform via countersunk bolts. The second ball valve fixture 5 is mounted on the first platform 3 via a second connecting seat 10. The second connecting seat 10 includes a sleeve-type lifting column and a locking nut. The outer wall of the lifting column is provided with axial scale lines, and its bottom end is embedded in a guide groove preset in the first platform 3. The installation height of the second ball valve fixture 5 is adjusted by rotating the locking nut. The C-shaped opening of the C-shaped ring opening of the first ball valve fixture 4 is parallel to the long side of the first platform 3, while the C-shaped opening of the second ball valve fixture 5 is perpendicular to the long side of the first platform 3, forming a spatially orthogonal layout.

[0036] The projections of the rotary joint maintenance support columns 6 on the maintenance platform 1 are distributed in an equilateral triangle shape, and the spacing between adjacent support columns is equal. The top of the support column is welded and fixed to the bottom surface of the second platform 7 through an annular connecting plate, and the central axis of the second platform 7 coincides with the geometric center formed by the axes of the three support columns. A plurality of circular airtight test holes are evenly opened along the circumference on the annular surface of the second platform 7, and the axes of the test holes all point to the center of the platform. A sealing ring made of fluororubber is embedded in the hole, and the outer edge of the sealing ring protrudes from the platform surface to form a compression contact surface. The fixed anchor point 12 on the side of the maintenance platform 1 includes a vertically welded ear plate structure, a through hole is opened in the center of the ear plate, and a detachable threaded bushing is assembled in the through hole. The internal thread specification of the threaded bushing matches the fastening bolt of the external clamp, and a triangular reinforcing rib is welded between the bottom surface of the ear plate and the side of the maintenance platform 1.

[0037] A maintenance method for an intelligent automatic maintenance device for a double ball valve of an LNG unloading arm comprises the following steps: S1. The maintenance platform is hoisted to the work area using the four-corner self-locking hoisting device. The hoisting device automatically triggers locking when it is subjected to force. The master control module, vibration monitoring module, and alarm module are started, and the AR auxiliary module is initialized. The industrial camera scans the work environment, and hand-eye calibration is completed using the checkerboard method to complete the hand-eye coordinate system conversion. The checkerboard calibration establishes the spatial mapping relationship between the industrial camera and the mechanical coordinate system, so that the AR virtual guidance is accurately aligned with the physical components. The edge computing unit loads the double ball valve model into the incremental knowledge base. The disassembly and assembly procedures and torque parameters are associated. The incremental knowledge base dynamically loads the disassembly and assembly procedures, and the AR guidance content is adaptively matched with the valve model. S2. Install external auxiliary equipment using threaded bushings at fixed anchor points. Place the discharge arm double ball valve on the first platform. The first and second ball valve fixtures are respectively fixed to the ball valves of the discharge arm double ball valve and clamped together by a hydraulic drive. The master control module controls the hydraulic drive to close the C-shaped clamp. The pressure sensor provides real-time feedback on the clamping force. If the clamping force exceeds the limit, the alarm module triggers an audible and visual alarm. S3. Adjust the height of the first connecting seat and the second connecting seat according to the axial scale line of the lifting sleeve, and the vibration monitoring module monitors the status of the hydraulic locking mechanism in real time; S4. After the rotary joint flange of the double ball valve of the unloading arm contacts the annular surface of the second platform, the AR glasses in the AR auxiliary module are superimposed with the proposed number to each airtight test hole, and a closed cavity is formed by the airtight test device. The external pressure detection equipment injects the detection medium into the adjacent airtight test devices in sections in turn. Specifically, the external pressure pump injects 0.8MPa detection medium into the adjacent test holes in sections; after each test is completed, the joint is rotated circumferentially to the corresponding position of the next group of airtight test devices, and the pressurization operation is repeated until all circumferential tests are covered; the wireless pressure sensor monitors the pressure attenuation, and performs step-by-step pressurization retesting on the points with large pressure drops. Specifically, the wireless pressure sensor monitors the pressure drop, and performs step-by-step pressurization retesting when the pressure drop is greater than 5%; and generates a leakage heat map and transmits it to the main control module; the edge computing unit compares the historical data, marks the abnormal interval and displays the leakage point in the AR glasses; S5: The disassembly and assembly of the double ball valves in the discharge arm and the inspection of the rotary joint flange can be performed simultaneously. AR glasses superimpose virtual disassembly and assembly instructions, specifically, superimposed bolt removal sequence animation and real-time torque curves. The welded frame of the reinforcement ribs and support columns under the platform distributes the load, and external equipment forms a reaction force support with the platform through fixed anchor points. S6. After the maintenance is completed, the hydraulic drive device releases the C-shaped annular opening, releases the clamping of the first ball valve fixing device, the second ball valve fixing device and the double ball valve of the unloading arm, resets the lifting sleeve to the initial height, releases the connection between the rotary joint flange and the airtightness test device on the annular surface of the second platform, releases the mechanical lock of the self-locking lifting device, and transfers the maintenance platform through the lifting device.

[0038] Example: The maintenance platform is constructed from 20mm-thick Q345B steel plate. U-shaped lifting lugs welded to the four corners serve as self-locking lifting devices. The inner surfaces of the lifting lugs feature 1mm-deep diamond-shaped anti-slip grooves. Honeycomb reinforcement ribs, 50mm high, are welded to the underside of the platform. The ribs are arranged in a hexagonal grid and secured to the base of the double-ball valve maintenance support columns and the rotary joint maintenance support columns via continuous fillet welds. In the double-ball valve maintenance device, two 200mm x 200mm rectangular steel columns are vertically secured to one side of the platform using M30 high-strength bolts. The top flanges of the support columns connect to the first platform, aligning the long side of the first platform with a distance of 500mm. Two orthogonally spaced C-shaped hydraulic clamps are installed on the first platform. The first ball valve fixture is secured to the rectangular base, with its C-shaped opening parallel to the long side of the first platform. The second ball valve fixture is mounted via a lifting sleeve with axial scale lines, with the C-shaped opening perpendicular to the long side of the platform. The hydraulic locking mechanism within the sleeve is electrically connected to the vibration monitoring module. The infrared positioning module on the inside of the fixture scans the center of the flange with an accuracy of 0.1mm. The hydraulic drive device receives instructions from the main control module to adjust the clamping force. The pressure sensor provides real-time feedback of data in the range of 0.5-2MPa, and triggers an audible and visual alarm when the limit is exceeded.

[0039] The three support columns of the rotary joint inspection device are arranged in an equilateral triangle (with a side length tolerance of ±2mm). A 1.2m-diameter annular second platform is welded to the top of the support columns via an annular connecting plate. Twelve airtightness test holes are evenly distributed around the platform (spaced 30° apart), each embedded with a fluororubber seal and a wireless pressure sensor. A servo motor drives a rotary table at the bottom of the second platform. The output shaft of the rotary table is coupled to the platform's center axis via a cross coupling, enabling step-by-step rotation with 0.01° accuracy. The industrial camera of the intelligent collaborative device is attached to the reinforcement rib via a universal magnetic base. A coordinate system transformation matrix is ​​established through checkerboard calibration. The edge computing unit runs the YOLOv7 model to identify valve components in the RGB-D image. The spatial matching engine aligns the bounding box with the CAD model in the incremental knowledge base and outputs a 6DoF pose matrix to the AR glasses. The AR glasses overlay the bolt removal sequence number and torque value instructions in the operator's field of view. If unauthorized operation is detected, the virtual screen freezes and a red light warning is triggered. The vibration monitoring module's piezoelectric sensors, located at the support column nodes, trigger an audible and visual alarm when an amplitude greater than 0.5mm is detected. The ear plate for fixing the anchor point is provided with a Φ20mm through hole, and the built-in hydraulic quick connector enables one-touch locking of the external clamp.

[0040] During maintenance, the platform is first hoisted to the work area, where the self-locking lifting lugs automatically lock the slings. During the AR-assisted module initialization phase, the industrial camera scans the environment and completes hand-eye calibration, while the edge computing unit loads the CAD model of the double-ball valve. The discharge arm double-ball valve is placed on the first platform: the horizontal valve is clamped in the first fixture, while the vertical valve is adjusted in height by a lifting sleeve and secured by the second fixture. A hydraulic actuator closes the C-shaped clamp, an infrared positioning module calibrates the flange center, and a pressure sensor implements closed-loop control. After the rotary joint flange is attached to the second platform, AR glasses overlay virtual numbers on the airtightness test holes. A 0.8MPa test medium is injected into each section. A wireless pressure sensor generates a leak heat map, and the edge computing unit identifies abnormal areas and projects them into the AR field of view. During the simultaneous disassembly and assembly of the double-ball valve and rotary joint inspection, honeycomb reinforcement ribs distribute vertical loads, and triangular support columns balance torque. After maintenance is complete, the clamp is hydraulically released, the indexing plate is reset, and the transfer platform is hoisted. This solution, through structural innovation and intelligent collaboration, addresses the technical shortcomings of traditional maintenance procedures, such as poor adaptability of multi-directional valves, large blind spots in seal inspection, and high manual operation risks.

[0041] After hoisting the inspection platform to the work area using a lifting device, external auxiliary equipment is installed using threaded bushings at the anchor points. The disassembled double ball valve is placed horizontally on the first platform, with the C-shaped ring opening structure of the first ball valve fixture clamping the valve flange parallel. For vertically mounted valves, the second ball valve fixture's sleeve-type lifting column is adjusted in height so that the second C-shaped ring opening fits vertically into the flange groove. Locking nuts are used to secure the height, creating a bidirectional constraint.

[0042] After the rotary joint flange contacts the annular surface of the second platform, airtight test holes at corresponding angles are selected and the sealing rings are tightened with bolts to form a sealed cavity. An external pressure testing device sequentially injects the test medium into adjacent test holes. After each test segment is completed, the joint is rotated circumferentially to align with the next set of test holes. The pressure application operation is repeated until all circumferential test points are covered.

[0043] During maintenance, the double-ball valve disassembly and assembly, along with rotary joint testing, can be performed simultaneously. The welded frame of the platform's reinforcement ribs and support columns distributes the load, while external equipment forms a reaction force support with the platform through anchor points. After maintenance is complete, the C-shaped ring-shaped opening structure clamps and test hole bolt connections are released, and the maintenance platform is transferred using a hoisting device. During the reset process, the platform's structural rigidity maintains component positioning accuracy.

[0044] The double ball valve maintenance method for the discharge arm provided by the present invention realizes efficient maintenance through the collaborative operation of the modular structure. The operator first hoisted the maintenance platform to the working area, and used the threaded bushings at the anchor points of the side ear plates to install external equipment such as hydraulic wrenches or auxiliary support arms to form an operating reference surface. The disassembled double ball valves are placed horizontally or vertically on the first platform according to the differences in their installation directions: the horizontal valve is clamped parallel to the flange by the C-shaped annular opening structure of the first ball valve fixing device, and the vertical valve drives the sleeve-type lifting column to lift the second C-shaped annular opening structure to the flange height by rotating the locking nut of the second ball valve fixing device, and uses the deformation of the rubber buffer layer in the open ring to compensate for the flange size tolerance to complete the two-way constraint. The orthogonal clamping layout of the two valves allows for simultaneous sealing surface grinding or valve seat replacement operations, reducing the workstation switching time.

[0045] During the inspection of the rotary joint, after its flange is fitted with the annular surface of the second platform, the operator selects three adjacent test holes as the initial inspection section based on the 30° interval distribution pattern of the circumferential airtight test holes. The flange is pressed against the fluororubber sealing ring of the corresponding test hole by M16 bolts to form a partially closed cavity. The external pressure pump injects the inspection medium into the test holes spaced 120° apart in a segmented jump manner. Each test covers an arc length of 120°, and the symmetrical structure of the equilateral triangle support column is used to balance the radial pressure. After each test is completed, the flange connection bolts are loosened, and the joint flange is manually rotated to the next set of test holes for alignment. The pressurization operation is repeated until the 360° full-circle inspection is completed. This segmented inspection strategy, combined with the mechanical stability of the annular platform, avoids the interference of pressure fluctuations during traditional continuous rotation inspection.

[0046] During the maintenance process, the disassembly and assembly of the double ball valve and the inspection of the rotary joint can be performed in parallel. The radial reinforcement ribs on the lower surface of the platform disperse the vertical load of the double ball valve and the torque load of the rotary joint to the support column. The external equipment forms a reaction force support chain with the platform through the anchor point, reducing the risk of platform deformation. After the maintenance is completed, the clamping of the C-shaped ring-shaped opening structure and the bolt connection of the test hole are released. When the lifting device transfers the platform, the welded frame of the reinforcement ribs and the support column maintains the rigidity of the platform to prevent the displacement of components. This method solves the efficiency bottleneck and lack of precision in traditional split maintenance through spatial layout optimization and mechanical path collaborative design.

[0047] The AR auxiliary module uses industrial cameras to collect three-dimensional point cloud data of the double ball valve in real time. Combined with the spatial matching engine of the edge computing unit, it accurately aligns the component bounding box identified by deep learning with the CAD model in the incremental knowledge base. This technical solution superimposes virtual contours on the actual valve surface in the operating field of view, forming a virtual and real fusion of disassembly and assembly instructions, significantly improving the positioning accuracy of complex structures. Operators can directly view virtual indicators such as the bolt removal sequence number and the highlighted sealing surface grinding area through AR glasses, eliminating the perspective switching errors caused by traditional drawing comparison. This enables adaptive matching of maintenance procedures for different valve models, reducing personnel training costs and ensuring operational standardization.

[0048] Any embodiment of the present invention may be used as an independent technical solution or in combination with other embodiments. All patents and publications mentioned in the present specification indicate that they are public technologies in the field and can be used in the present invention. All patents and publications cited herein are also listed in the references, just as each publication is specifically cited individually. The present invention herein can be implemented in the absence of any element or elements, one limitation or multiple limitations, where such limitations are not specifically stated. The terms and expressions used herein are descriptive and not limiting, and there is no intention to indicate that the terms and explanations described in this book exclude any equivalent features. However, it is understood that any appropriate changes or modifications can be made within the scope of the present invention and the claims. It is understood that the embodiments described in the present invention are examples and features in some embodiments, and anyone skilled in the art can make some changes and modifications based on the essence of the description of the present invention, and these changes and modifications are also considered to fall within the scope of the present invention and the scope of the independent claims and appended claims.

Claims

1. An intelligent automatic maintenance device for double ball valves of LNG unloading arm, characterized by: include: The maintenance platform has self-locking lifting devices at the four corners; A double ball valve maintenance device is provided on one side of the maintenance platform, comprising two vertically mounted double ball valve maintenance support columns, the upper ends of which are connected to a first platform, the long sides of which are parallel to the side edges of the maintenance platform; A double ball valve fixing device is provided on the first platform, and the double ball valve fixing device includes a first ball valve fixing device and a second ball valve fixing device; A rotary joint maintenance device is provided on the other side of the maintenance platform, comprising three vertically mounted rotary joint maintenance support columns, wherein the distance between each of the three rotary joint maintenance support columns and the orthographic projections of the other two rotary joint maintenance support columns on the maintenance platform is equal, and the upper ends of the rotary joint maintenance support columns are connected to an annular second platform, and the second platform is provided with a plurality of equally spaced airtight test devices along the circumference; The intelligent collaborative device is installed on the maintenance platform and includes a vibration monitoring module, an AR auxiliary module, and an alarm module, which are electrically connected to the main control module respectively.

2. The intelligent automatic maintenance device for double ball valves of LNG unloading arm according to claim 1 is characterized in that: The AR auxiliary module includes: The industrial camera is installed above the maintenance platform. The checkerboard method is used to determine the industrial camera-mechanical coordinate system conversion matrix. It is used to collect the 3D point cloud data of the double ball valve in real time and transmit the RGB image and 3D point cloud data to the edge computing unit. The edge computing unit is used to run the deep learning model, input the image to the YOLOv7 segmentation network, identify the double ball valve in real time, output the component type and bounding box, align the recognition result with the model in the knowledge base through the spatial matching engine, and output the 3D matrix to the AR glasses; Incremental knowledge base, used to update and store models, disassembly and assembly procedures, and torque parameters of double ball valves and rotary joints; AR glasses are used to provide virtual guidance in the maintenance personnel's field of view and superimpose virtual outlines on the real double ball valve.

3. The intelligent automatic maintenance device for double ball valves of LNG unloading arm according to claim 1 is characterized in that: The double ball valve maintenance support column is fixedly connected to the maintenance platform by bolts, and the axis of the double ball valve maintenance support column is perpendicular to the upper surface of the maintenance platform. The double ball valve fixing device is a C-shaped ring opening, the first ball valve fixing device is connected to the first platform through a first connecting seat, and the second ball valve fixing device is connected to the first platform through a second connecting seat, and the height of the second connecting seat is greater than the height of the first connecting seat; the arc cross-section of the first ball valve fixing device is parallel to the long side of the first platform, and the arc cross-section of the second ball valve fixing device is perpendicular to the long side of the first platform.

4. The intelligent automatic maintenance device for double ball valves of LNG unloading arm according to claim 3 is characterized in that: The first connecting seat and the second connecting seat are both adjustable lifting structures, and the adjustable lifting structure is a lifting sleeve. The outer wall of the lifting sleeve is provided with axial scale lines, and the interior of the lifting sleeve is provided with a hydraulic locking mechanism, which is electrically connected to the vibration monitoring module.

5. The intelligent automatic maintenance device for double ball valves of LNG unloading arm according to claim 3 is characterized in that: The double-ball valve fixing device is a hydraulically driven adaptive clamp. The hydraulic driving device is arranged inside the first connecting seat and the second connecting seat. An infrared positioning module and a pressure sensor are provided on the inner side of the C-shaped ring opening of the double-ball valve fixing device. The infrared positioning module and the pressure sensor are electrically connected to the main control module, and the main control module is electrically connected to the hydraulic driving device.

6. The intelligent automatic maintenance device for double ball valves of LNG unloading arm according to claim 1 is characterized in that: The airtight test device is an airtight test hole, the spacing between the airtight test holes is 1 / 12 to 1 / 8 of the circumference of the second platform, and each airtight test hole is embedded with a wireless pressure sensor and a sealing rubber ring, and the wireless pressure sensor is electrically connected to the main control module.

7. The intelligent automatic maintenance device for double ball valves of LNG unloading arm according to claim 1 is characterized in that: The vibration monitoring module is arranged on the double ball valve maintenance support column and the rotary joint maintenance support column and is connected to the sound and light display device, and the alarm module is arranged below the double ball valve fixing device.

8. The intelligent automatic maintenance device for double ball valves of LNG unloading arm according to claim 1 is characterized in that: The maintenance platform is also provided with a fixed anchor point, which is arranged at the side of the maintenance platform between the double ball valve maintenance device and the rotary joint maintenance device, and is used to fix external equipment. The fixed anchor point is provided with a hydraulic quick connector for one-click locking of external clamps. The fixed anchor point includes an ear plate vertically arranged on the side of the maintenance platform, and the ear plate is provided with a through bolt hole for connecting external clamps.

9. The intelligent automatic maintenance device for double ball valves of LNG unloading arm according to claim 1 is characterized in that: The lower surface of the maintenance platform is provided with a plurality of reinforcing ribs, which are distributed in a honeycomb shape and are welded and fixed to the bottom of the double ball valve maintenance support column and the rotary joint maintenance support column. The lifting device is a lifting ear, which is a U-shaped structure and is welded to the four corner edges of the maintenance platform, and the inner side of the lifting ear is provided with anti-slip grooves.

10. A maintenance method for an intelligent automatic maintenance device for double ball valves of an LNG unloading arm, applied to the intelligent automatic maintenance device for double ball valves of an LNG unloading arm according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. The maintenance platform is hoisted to the work area using the four-corner self-locking hoisting device. The hoisting device automatically triggers locking when it is subjected to force. The master control module, vibration monitoring module, and alarm module are activated, and the AR auxiliary module is initialized. The industrial camera scans the work environment, and hand-eye calibration is completed using the checkerboard method. The edge computing unit loads the double-ball valve model into the incremental knowledge base. S2. Use the threaded bushings at the fixed anchor points to install external auxiliary equipment, place the discharge arm double ball valve on the first platform, and fix the first ball valve fixing device and the second ball valve fixing device to the ball valves of the discharge arm double ball valve respectively and clamp them through the hydraulic drive device; S3. Adjust the height of the first connecting seat and the second connecting seat according to the axial scale line of the lifting sleeve, and the vibration monitoring module monitors the status of the hydraulic locking mechanism in real time; S4. After the rotary joint flange of the double ball valve of the discharge arm contacts the annular surface of the second platform, the AR glasses in the AR auxiliary module are superimposed with the proposed number to each airtight test hole, and a closed cavity is formed through the airtight test device. The external pressure detection equipment injects the detection medium into the adjacent airtight test devices in sections in sequence. After each test is completed, the joint is rotated circumferentially to the corresponding position of the next set of airtight test devices, and the pressurization operation is repeated until all circumferential tests are covered; the wireless pressure sensor monitors the pressure decay, and performs step-by-step pressurization retests on the points with the largest pressure drop, and generates a leakage heat map and transmits it to the main control module; the edge computing unit compares historical data, marks abnormal intervals, and displays the leakage points in the AR glasses; S5: The disassembly and assembly of the double ball valves in the discharge arm and the inspection of the rotary joint flange can be performed simultaneously. AR glasses superimpose virtual disassembly and assembly instructions. The welded frame of the reinforcement ribs and support columns under the platform distributes the load. External equipment forms a reaction force support with the platform through fixed anchor points. S6. After the maintenance is completed, the hydraulic drive device releases the C-shaped annular opening, releases the clamping of the first ball valve fixing device, the second ball valve fixing device and the double ball valve of the unloading arm, resets the lifting sleeve to the initial height, releases the connection between the rotary joint flange and the airtightness test device on the annular surface of the second platform, releases the mechanical lock of the self-locking lifting device, and transfers the maintenance platform through the lifting device.

Images