Method for adjusting flatness of tank wall of liquefied gas storage and transportation tank

Abstract

The application discloses a kind of tank wall flatness adjustment methods of liquefied gas storage and transportation tank.The method comprises: a plurality of measuring components are respectively arranged in multiple positioning points;Measuring component includes target ball base and measuring wedge with preset height;At least one target ball is arranged in the target ball base of a plurality of measuring components, and the measuring height data of at least one target ball relative to the inner surface of support structure is obtained;Move at least one target ball to other unmeasured target ball base, and obtain the measuring height data of target ball;Move a plurality of measuring components to other unmeasured positioning points, move at least one target ball to unmeasured target ball base, and obtain the measuring height data of target ball;The measuring height data is input into tank wall flatness adjustment model, and the target height data of a plurality of supporting wedges is determined.Integrated measuring component is formed, so that the measuring reference of measuring stage is consistent with the actual supporting surface of supporting wedge in installation stage, and system error is eliminated.

Description

Technical Field

[0001] This invention relates to the field of liquefied natural gas (LNG) storage tank enclosure film manufacturing technology, specifically a method for adjusting the flatness of the tank wall of an LNG storage and transportation tank. Background Technology

[0002] Cryogenic membrane tanks are large storage tank structures used for storing cryogenic media such as liquefied natural gas (LNG), typically for the storage and long-distance transportation of LNG. A cryogenic membrane tank generally consists of a main sealing layer, a main plywood layer, a secondary sealing layer, and an insulation box from the inside out. Each insulation box is installed on the hull of the LNG vessel using wedges. Because construction errors are unavoidable during the building process, wedges of varying thicknesses are installed at various positioning points between the insulation box and the hull to compensate for surface unevenness and meet the flatness requirements for the insulation box installation.

[0003] During the marking and marking process for LNG vessels, target balls need to be set at each positioning point, and three-dimensional position data of each positioning point needs to be obtained through a laser tracker to calculate the thickness of the wedge block at each positioning point. In actual construction, there are many pits and depressions of varying depths on the hull of the vessel. If the positioning point is located in a pit or depression, the target ball will also be embedded in the pit or depression to some extent, resulting in a large error in the calculation results and increasing construction time and costs.

[0004] Therefore, there is a need to provide a method for adjusting the flatness of the tank wall to at least partially solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank, which solves the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank. The liquefied gas storage and transportation tank is arranged in a support structure and includes multiple tank walls, which are connected to each other and fixed to the support structure. Multiple positioning points are disposed on the inner surface of the support structure, and multiple support wedges are respectively disposed at the multiple positioning points. The tank walls are disposed on the inner surface of the support structure through the multiple support wedges. The method for adjusting the flatness of the tank wall includes:

[0008] Several measuring components are respectively set at the plurality of positioning points; each measuring component includes a target ball base and a measuring wedge with a preset height; the target ball base is set on the mating surface of the measuring wedge with the preset height; the size of the mating surface is larger than the size of the target ball base, and the number of the several measuring components is less than or equal to the number of the plurality of positioning points;

[0009] At least one target ball is placed inside the target ball base of the plurality of measuring components, and the at least one target ball is scanned by a laser tracker to obtain the measured height data of the at least one target ball relative to the inner surface of the support structure; the number of target balls is less than or equal to the number of target ball bases;

[0010] Move at least one target ball into another unmeasured target ball base until the measured height data of the target ball in all other unmeasured target ball bases is obtained;

[0011] Move the plurality of measuring components to other unmeasured positioning points, and move the at least one target ball to the unmeasured target ball base, until the measured height data of the target ball at all other unmeasured positioning points is obtained;

[0012] The measured height data is input into the tank wall flatness adjustment model to determine the target height data of the multiple support wedges.

[0013] By setting the target ball base on the mating surface of the measuring wedge with a preset height, the measurement reference of the target ball during the measurement stage is kept consistent with the actual support surface of the support wedge during the installation stage. This eliminates the systematic error caused by the inconsistency in the amount of sinking at the pit positioning point due to the different dimensions of the target ball base and the support wedge in the traditional method. The height data obtained by measurement directly reflects the actual positioning state of the support wedge after installation, thereby reducing measurement errors, improving the accuracy of tank wall flatness adjustment, and meeting the flatness requirements of insulation box installation.

[0014] Preferably, before setting the plurality of measuring components at the plurality of positioning points, the method further includes:

[0015] The target ball base is temporarily fixed to the mating surface of the measuring wedge by adhesive bonding.

[0016] The target ball base is temporarily fixed to the mating surface of the measuring wedge by adhesive bonding, so that the target ball base and the measuring wedge form a synchronously movable integral measuring component, avoiding the relative displacement of the target ball base during the scanning measurement process and the resulting measurement error. At the same time, the adhesive bonding fixation does not require additional fasteners, and the disassembly and assembly are convenient. After the measurement is completed, the target ball base and the measuring wedge can be quickly separated without affecting the subsequent installation of the support wedge and the insulation box.

[0017] Preferred, specifically including:

[0018] The target ball base is attached to the mating surface of the measuring wedge using removable pressure-sensitive tape.

[0019] Removable pressure-sensitive tape is used to temporarily bond and fix the target ball base to the measuring wedge. The bonding operation is simple and reliable, and there is no adhesive residue after removal, which does not affect the reusability of the measuring wedge or the subsequent installation accuracy. Butyl tape can be used as the removable pressure-sensitive tape, which can maintain stable bonding performance and removability in low-temperature construction environment, and is suitable for the construction conditions of liquefied gas storage and transportation tanks.

[0020] Preferably, before setting the plurality of measuring components at the plurality of positioning points, the method further includes:

[0021] The mounting surface of the measuring wedge is temporarily fixed to the positioning point by adhesive bonding; the mounting surface is the other surface opposite the mating surface of the measuring wedge.

[0022] The measuring wedge is temporarily fixed to the positioning point by adhesive bonding, which keeps the measuring wedge in a stable position during laser scanning and avoids measurement errors caused by displacement of the measuring wedge due to personnel touch or environmental vibration. At the same time, the adhesive bonding is a detachable connection, which can be quickly removed and transferred to the next unmeasured positioning point after the measurement is completed. This allows for cyclic measurement of all positioning points with a small number of measuring wedges, improving measurement efficiency, and does not affect the subsequent installation of support wedges and insulation boxes.

[0023] Preferred, specifically including:

[0024] The mounting surface of the measuring wedge is bonded to the positioning point using a non-curing, plastic-filled adhesive material.

[0025] A non-curing, plastic, filler adhesive material is used to temporarily fix the measuring wedge to the positioning point. This material is plastic and can fill the gap between the mounting surface of the measuring wedge and the pit of the supporting structure, so that the bottom surface of the measuring wedge and the supporting structure form a surface contact rather than a point contact. On the one hand, this increases the bonding area and improves the fixing strength. On the other hand, it makes the positioning state of the measuring wedge closer to the actual installation state of the supporting wedge, further reducing the measurement error caused by the difference in the bottom surface contact state. At the same time, the non-curing material always maintains viscoelasticity, and can be completely peeled off without residue when removed, which facilitates the transfer and reuse of the measuring components.

[0026] Preferably, the bottom surface dimension of the measuring wedge is the same as the bottom surface dimension of the supporting wedge; and / or,

[0027] The target ball base is positioned at the center of the mating surface of the measuring wedge; and / or,

[0028] The positioning point is located at the center of the mating surface of the measuring wedge.

[0029] By ensuring that the bottom dimensions of the measuring wedge and the supporting wedge are identical, the degree of depression of the measuring wedge and the supporting wedge at the pit positioning point is completely consistent. This ensures that the height data obtained during the measurement phase accurately corresponds to the actual height of the supporting wedge after installation, eliminating measurement system errors caused by dimensional differences and further improving the flatness adjustment accuracy. By positioning the positioning point at the center of the measuring wedge mating surface, it ensures that the supporting wedge provides equal support force to the adjacent corners of the four adjacent insulation boxes after installation. This avoids uneven force distribution on the insulation boxes due to support eccentricity, which affects the overall flatness and guarantees the stability and uniformity of the insulation box installation. By placing the target ball base at the center of the measuring wedge mating surface, the projection of the target ball on the support structure coincides with the center of the measuring wedge. This ensures that the height data measured by the target ball represents the height of the measuring wedge's center position, avoiding height measurement deviations introduced by target ball offset and improving measurement accuracy.

[0030] Preferably, before inputting the measured height data into the tank wall flatness adjustment model, the method further includes:

[0031] Establish tank wall flatness constraints for each of the aforementioned tank walls;

[0032] Using the minimization of the sum of the height adjustment values ​​of the measuring components as the objective function, the tank wall flatness constraint of each tank wall is combined to construct the tank wall flatness adjustment model.

[0033] Preferably, establishing the tank wall flatness constraint includes:

[0034] In the first direction of the tank wall, for three adjacent measuring components i, j, k, a first constraint is configured:

[0035] ;

[0036] In the second direction of the tank wall, for three adjacent measuring components Configure the second constraint for m and n:

[0037] ;

[0038] The first direction is perpendicular to the second direction; z i z j z k These represent the Z-axis coordinates of measurement components i, j, and k in the tank wall coordinate system after height adjustment; x i x j x k These are the coordinates of measuring components i, j, and k along the first direction in the tank wall coordinate system after height adjustment; z l z m z nThese represent the Z-axis coordinates of the measuring components l, m, and n in the tank wall coordinate system after height adjustment; y l y m y n These are the coordinates of the measuring components l, m, and n along the second direction in the tank wall coordinate system after height adjustment; A is the tank wall flatness tolerance.

[0039] Preferably, the objective function is configured as follows:

[0040] ;

[0041] M represents the total number of tank walls; Nm represents the total number of measuring components on the m-th tank wall; This is the height adjustment value of the p-th measuring component on the m-th tank wall.

[0042] Preferably, the measuring wedge is made of magnetic material and is magnetically attracted and fixed to the inner surface of the support structure; the target ball base is made of magnetic material or has magnetic components and is magnetically attracted and fixed to the mating surface of the measuring wedge.

[0043] The measuring wedge and target ball base, made of magnetic materials, temporarily fix the measuring wedge to the inner surface of the support structure and the target ball base to the measuring wedge using magnetic attraction. No adhesive is required, making assembly and disassembly more convenient and enabling rapid positioning and transfer of the measuring components, further improving measurement efficiency. After removal of the magnetic fixation, no adhesive residue remains, ensuring no impact on subsequent processing of the inner surface of the support structure or the installation accuracy of the support wedge. Furthermore, the measuring wedge and target ball base are reusable, reducing construction costs. Simultaneously, the magnetic attraction provides stable fixing force, ensuring no displacement of the measuring components during laser scanning and guaranteeing the accuracy of the measurement data. This design is suitable for adjusting the flatness of the inner surface of steel support structures.

[0044] The present invention also provides a liquefied gas storage and transportation tank, the liquefied gas storage and transportation tank including a plurality of support wedges having target height data obtained according to the tank wall flatness adjustment method of the liquefied gas storage and transportation tank as described above.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] This invention forms an integrated measurement component by setting the target ball base on a measuring wedge with a preset height. This ensures that the measurement reference during the measurement phase is consistent with the actual support surface of the support wedge during the installation phase. This fundamentally eliminates the systematic error caused by the difference in size between the target ball base and the support wedge at the pit positioning point in traditional methods. It enables direct measurement of the actual positioning state of the support wedge, significantly improving the measurement accuracy of tank wall flatness adjustment. This invention ensures measurement accuracy while also taking into account construction efficiency and ease of operation, providing a reliable technical solution for high-precision adjustment of the flatness of liquefied gas storage and transportation tank walls. Attached Figure Description

[0047] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0048] Figure 1 This is a schematic diagram of the structure of the liquefied gas storage and transportation tank provided in an embodiment of the present invention;

[0049] Figure 2 This is a schematic diagram of the arrangement of the insulation box on the support structure via support wedges, as provided in an embodiment of the present invention.

[0050] Figure 3 This is a schematic diagram of the arrangement of the support wedges on the support structure according to an embodiment of the present invention;

[0051] Figure 4 This is a flowchart of the tank wall flatness adjustment method provided in the embodiment of the present invention;

[0052] Figure 5 This is a schematic diagram of the first device structure for positioning the location of the positioning point provided in an embodiment of the present invention;

[0053] Figure 6 This is a schematic diagram of the second device structure for positioning the location of the positioning point provided in an embodiment of the present invention;

[0054] 10. Liquefied gas storage and transportation tank; 101. First tank wall; 102. Second tank wall; 103. Third tank wall; 100. Support structure; 200. Support wedge; 300. Measuring wedge; 400. Insulation box; 20. Target ball; 21. Target ball base; 201. Removable pressure-sensitive tape; 202. Non-curing plastic filler adhesive material. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0056] In the description of this invention, it should be understood that, unless otherwise stated, the terms "center," "perpendicular to the wall thickness direction," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0057] Furthermore, unless otherwise stated, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0058] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0060] Example 1

[0061] Understandably, referring to Figure 1 As shown, the liquefied gas storage and transportation tank 10 is formed by multiple tank walls (e.g., first tank wall 101, second tank wall 102, or third tank wall 103). It is understood that the liquefied gas storage and transportation tank is used to safely store and transport liquefied natural gas at extremely low temperatures of -163°C, as shown in the reference. Figure 2 As shown, the tank wall is assembled from multiple insulating boxes. Each insulating box is installed on the supporting structure 100 via support wedges 200 laid at positioning points. Since the supporting structure 100 cannot be perfectly flat during construction, and liquefied gas storage tanks have extremely high requirements for the flatness of the insulating boxes, the thickness of the support wedges 200 is adjusted to compensate for construction errors in the supporting structure 100 and meet the flatness requirements for the insulating box installation in order to fill in unevenness and compensate for component errors. When laying the insulating boxes 400, different thicknesses of support wedges can be selected to fine-tune the levelness of each insulating box 400. For example, for a square insulating box 400, each insulating box 400 is configured with a set of four support wedges 200, corresponding to the four corners of the square insulating box. The four support wedges can be selected with different thicknesses according to the actual height requirements of the insulating box 400. Figure 3 As shown, each wall of the support structure 100 is equipped with multiple positioning points, and support wedges 200 are installed at the positioning points, and then insulation boxes 400 are laid.

[0062] Understandably, the membrane enclosure system is a multi-layered composite structure, closely fitted to the hull of the ship. From the inside out, it includes: a primary shielding layer, a primary insulation layer, a secondary shielding layer, and a secondary insulation layer. The primary shielding layer is the innermost layer, directly in contact with the liquefied natural gas, providing the first line of sealing protection. The primary insulation layer, located between the primary and secondary shielding layers, provides thermal insulation. The secondary shielding layer is the second line of defense, preventing further leakage of the liquefied cargo in the event of a leak in the primary shielding layer. The secondary insulation layer, located between the secondary shielding layer and the hull, further enhances the insulation effect. The outermost layer is the hull's steel plate, providing structural support for the entire membrane enclosure system.

[0063] The support structure is a solid structure. To enable the electronic device to optimize the thickness of each wedge using subsequent methods, the geometric data of the wedge mounting positions (i.e., positioning points) must first be determined. In some embodiments, this geometric data can be determined using the spatial coordinates of the positioning points. On one hand, the positioning points are markers on the support structure used to obtain the coordinates of that position; on the other hand, the positioning points characterize the mounting position of the wedges. In some embodiments, the three-dimensional positioning data is determined using a target sphere and a laser rangefinder. Specifically, a target sphere is placed at each mounting point. The target sphere is a reflective measurement marker with a standard geometric shape (typically a high-precision sphere) and its surface is coated with a high-reflectivity coating (e.g., aluminum dioxide, magnesium fluoride, etc.). It can reflect the incident laser back to its original position. The laser rangefinder is placed at a nearby fixed point (e.g., a temporary support within the support structure or a reference point with known coordinates), and it uses laser pulse or phase measurement principles to measure distance. During measurement, the laser rangefinder emits a laser beam towards each target sphere and receives the echo signals reflected from the target spheres. Based on the laser's time of flight or phase difference, the distance between the laser rangefinder and each target sphere is obtained. After obtaining these distances, a local spatial rectangular coordinate system (i.e., a local coordinate system) is established with the spatial position of the laser rangefinder as the origin. Based on the distance between the laser rangefinder and each target sphere, combined with the direction angles of the laser beam on the three coordinate axes, the three-dimensional position data of each positioning point is determined. The number and arrangement density of the target spheres can be determined according to the measurement accuracy requirements. For example, several target spheres can be evenly arranged on each support structure to cover the entire area of ​​the support structure.

[0064] Reference Figure 4 As shown in the figure, an embodiment of the present invention proposes a method for adjusting the flatness of a tank wall, including the following steps:

[0065] S100. Several measuring components are respectively set at multiple positioning points;

[0066] S200. At least one target ball is placed in the target ball base of several measuring components, and at least one target ball is scanned by a laser tracker to obtain the measurement height data of at least one target ball relative to the inner surface of the support structure.

[0067] like Figures 5-6As shown, the measuring component includes a target ball base and a measuring wedge with a preset height. The target ball is placed in the target ball base, and the two are fixed by magnetic attraction. The target ball base is set on the mating surface of the measuring wedge with the preset height, and the size of the mating surface is larger than the size of the target ball base. In actual construction, if the positioning point is located in a pit, the target ball base will also sink into the pit to some extent during the measurement stage. However, the size of the wedge is usually larger than the size of the target ball base, and the wedge will not sink into the pit. Therefore, the installation of the target ball base on the hull is different from that of the wedge on the hull. This causes the height adjustment value calculated during the measurement stage to be directly applied to the wedge installation during the installation stage, which will not meet the accuracy requirements of the flatness of the insulation box installation. In this embodiment, the target ball base is set on the mating surface of the measuring wedge during the measurement stage, avoiding the situation where the target ball base sinks into the pit while the wedge does not. The actual installation situation is measured directly, reducing measurement errors and improving the flatness adjustment accuracy.

[0068] S300, Move at least one target ball into another unmeasured target ball base until the measured height data of the target ball in all other unmeasured target ball bases is obtained;

[0069] S400, Move several measuring components to other unmeasured positioning points, move at least one target ball to the unmeasured target ball base, until the measured height data of the target ball at all other unmeasured positioning points are obtained;

[0070] The number of several measuring components is less than or equal to the number of multiple positioning points, and the number of target balls is less than or equal to the number of target ball bases;

[0071] S500: Input the measured height data into the tank wall flatness adjustment model to determine the target height data of several support wedges.

[0072] In this embodiment, before setting the various measuring components at the various positioning points, the tank wall flatness adjustment method further includes: temporarily fixing the target ball base to the mating surface of the measuring wedge by adhesive bonding. The target ball base and the wedge are temporarily joined by adhesive bonding. This method allows for the use of fewer target ball bases to measure all the measuring wedges, and also facilitates the removal of the measuring components after measurement for subsequent installation of the wedges and insulation box.

[0073] like Figure 6 As shown, in one optional embodiment, the tank wall flatness adjustment method specifically includes: attaching the target ball base 21 to the mating surface of the measuring wedge 300 using a removable pressure-sensitive adhesive tape 201. The removable pressure-sensitive adhesive tape can be butyl tape, which offers high construction efficiency and facilitates the removal of the measuring components after measurement for subsequent installation of the wedge and insulation box.

[0074] In this embodiment, before setting the various measuring components at the various positioning points, the tank wall flatness adjustment method further includes: temporarily fixing the mounting surface of the measuring wedge to the positioning point by adhesive bonding; the mounting surface is the other surface opposite the mating surface of the measuring wedge. Temporarily installing the measuring wedge to the positioning point by adhesive bonding allows for the use of a small number of measuring wedges to measure all positioning points, and also facilitates the removal of the measuring components after measurement for subsequent installation of the wedges and insulation box.

[0075] like Figure 6 As shown, in one optional embodiment, the tank wall flatness adjustment method specifically includes: bonding the mounting surface of the measuring wedge 300 to the positioning point using a non-curing plastic filler adhesive 202. The non-curing plastic filler adhesive can be butyl putty. Filling the gap between the mounting surface of the measuring wedge and the pits in the supporting structure with the non-curing plastic filler adhesive increases the bonding surface area and improves the fixing strength. It also facilitates the removal of the measuring components after measurement for subsequent installation of the wedge and insulation box.

[0076] Furthermore, the measuring wedge is made of magnetic material and is magnetically attracted and fixed to the inner surface of the supporting structure. The target ball base is also made of magnetic material or equipped with magnetic components and is magnetically attracted and fixed to the mating surface of the measuring wedge. The use of magnetic materials for the measuring wedge and target ball base allows for temporary fixation of the measuring wedge to the inner surface of the supporting structure and the target ball base to the measuring wedge, respectively, through magnetic attraction. This eliminates the need for adhesive materials, making assembly and disassembly more convenient and enabling rapid positioning and transfer of the measuring components, further improving measurement efficiency. After removal of the magnetic fixation, no adhesive residue remains, ensuring no impact on subsequent processing of the inner surface of the supporting structure or the installation accuracy of the supporting wedge. The measuring wedge and target ball base are reusable, reducing construction costs. Simultaneously, the magnetic attraction provides a stable fixing force, ensuring that the measuring components do not shift during laser scanning and guaranteeing the accuracy of the measurement data. This method is suitable for adjusting the flatness of the inner surface of steel supporting structures.

[0077] In this embodiment, the bottom surface dimensions of the measuring wedge are the same as those of the supporting wedge, ensuring that the measuring wedge and the supporting wedge are in the same degree of pitting, reducing measurement errors and improving the flatness adjustment accuracy.

[0078] The target ball base is positioned at the center of the mating surface of the measuring wedge; the positioning point is located at the center of the mating surface of the measuring wedge. For example... Figure 2As shown, the adjacent corners of the four adjacent insulation boxes are pressed together by a support wedge. The positioning point is located at the center of the measuring wedge to ensure that the support wedge provides equal support to the four adjacent insulation boxes when it is installed at the positioning point. The target ball base is set at the middle of the mating surface of the measuring wedge to ensure that the projection of the target ball on the support structure coincides with the positioning point, thereby reducing measurement errors and improving the flatness adjustment accuracy.

[0079] In this embodiment, before inputting the measured height data into the tank wall flatness adjustment model, the following steps are also included:

[0080] Establish tank wall flatness constraints for each tank wall separately;

[0081] Using the minimization of the sum of height adjustment values ​​of the measurement components as the objective function, a tank wall flatness adjustment model is constructed by simultaneously establishing tank wall flatness constraints for each tank wall.

[0082] Specifically, establishing tank wall flatness constraints includes:

[0083] In the first direction along the tank wall, for three adjacent measurement components i, j, and k, a first constraint is configured:

[0084] ;

[0085] On the second direction of the tank wall, for three adjacent measuring components Configure the second constraint for m and n:

[0086] ;

[0087] The first direction is perpendicular to the second direction; z i z j z k These represent the Z-axis coordinates of measurement components i, j, and k in the tank wall coordinate system after height adjustment; x i x j x k These are the coordinates of measuring components i, j, and k along the first direction in the tank wall coordinate system after height adjustment; z l z m z n These represent the Z-axis coordinates of the measuring components l, m, and n in the tank wall coordinate system after height adjustment; y l y m y n These are the coordinates of the measuring components l, m, and n along the second direction in the tank wall coordinate system after height adjustment; A is the tank wall flatness tolerance, representing the maximum allowable height difference over a one-meter length, which can be determined according to the type of insulation box and installation accuracy requirements, for example, 1.25mm, 2mm, or 3mm.

[0088] The physical meaning of the above constraint is that, among three adjacent installation points, the absolute value of the difference between the slope of the first segment (i→j) and the slope of the second segment (j→k) should not exceed the preset tolerance value 2A. This constraint ensures that the height change between installation points is smooth and does not result in drastic fluctuations. The flatness is controlled by using the slope difference between three adjacent points rather than the absolute value of a single point because the installation of insulation boxes is more sensitive to local relative height changes than absolute height changes.

[0089] In practical engineering, the value of A can be determined based on factors such as the type of insulation box, installation accuracy requirements, and construction errors of the supporting structure. For example, the value of A can be 0.2mm, 0.5mm, or 1mm, etc.

[0090] What needs to be understood is that z i z j z k Let i, j, and k be the Z-coordinate values ​​after the support wedges are installed at installation points i, j, and k, respectively. The relationship between these values ​​and the installation measurement wedges and height adjustment values ​​is as follows: . The Z coordinate of the measuring wedge when installing the positioning point i; Let be the height adjustment value of the wedge block at installation point i. Therefore, the in-plane flatness constraint is essentially a linear constraint on the shim value at each installation point.

[0091] In addition, the objective function is configured as follows:

[0092] ;

[0093] M represents the total number of tank walls; Nm represents the total number of measuring components on the m-th tank wall; This is the height adjustment value of the p-th measuring component on the m-th tank wall.

[0094] The physical meaning of this objective function is that the smaller the wedge height, the less wedge material is required, and the less filling material (such as resin putty) is used, resulting in lower construction costs. It can be understood that the objective function is a linear function of all design variables, eliminating local extrema and facilitating subsequent optimization. In this embodiment, a linear programming algorithm is used to solve the global optimization model to obtain the optimal wedge height for each installation point.

[0095] Example 2

[0096] This embodiment also provides a liquefied gas storage and transportation tank, which includes a plurality of support wedges with target height data obtained according to the tank wall flatness adjustment method of the liquefied gas storage and transportation tank in Embodiment 1.

[0097] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank, wherein the liquefied gas storage and transportation tank is arranged in a support structure and includes multiple tank walls, the multiple tank walls being connected to each other and fixed to the support structure; multiple positioning points are arranged on the inner surface of the support structure, and multiple support wedges are respectively disposed at the multiple positioning points, the tank walls being disposed on the inner surface of the support structure through the multiple support wedges; characterized in that... The method for adjusting the flatness of the tank wall includes: Several measuring components are respectively set at the plurality of positioning points; each measuring component includes a target ball base and a measuring wedge with a preset height; the target ball base is set on the mating surface of the measuring wedge with the preset height; the size of the mating surface is larger than the size of the target ball base, and the number of the several measuring components is less than or equal to the number of the plurality of positioning points; At least one target ball is placed inside the target ball base of the plurality of measuring components, and the at least one target ball is scanned by a laser tracker to obtain the measured height data of the at least one target ball relative to the inner surface of the support structure; the number of target balls is less than or equal to the number of target ball bases; Move at least one target ball into another unmeasured target ball base until the measured height data of the target ball in all other unmeasured target ball bases is obtained; Move the plurality of measuring components to other unmeasured positioning points, and move the at least one target ball to the unmeasured target ball base, until the measured height data of the target ball at all other unmeasured positioning points is obtained; The measured height data is input into the tank wall flatness adjustment model to determine the target height data of the multiple support wedges.

2. The method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank according to claim 1, characterized in that, Before setting the various measuring components at the multiple positioning points, the method further includes: The target ball base is temporarily fixed to the mating surface of the measuring wedge by adhesive bonding.

3. The method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank according to claim 2, characterized in that, Specifically, it includes: The target ball base is attached to the mating surface of the measuring wedge using removable pressure-sensitive tape.

4. The method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank according to claim 1, characterized in that, Before setting the various measuring components at the multiple positioning points, the method further includes: The mounting surface of the measuring wedge is temporarily fixed to the positioning point by adhesive bonding; the mounting surface is the other surface opposite the mating surface of the measuring wedge.

5. The method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank according to claim 4, characterized in that, Specifically, it includes: The mounting surface of the measuring wedge is bonded to the positioning point using a non-curing, plastic-filled adhesive material.

6. The method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank according to claim 1, characterized in that, The bottom surface dimension of the measuring wedge is the same as the bottom surface dimension of the supporting wedge; and / or, The target ball base is positioned at the center of the mating surface of the measuring wedge; and / or, The positioning point is located at the center of the mating surface of the measuring wedge.

7. The method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank according to claim 1, characterized in that, Before inputting the measured height data into the tank wall flatness adjustment model, the following steps are also included: Establish tank wall flatness constraints for each of the aforementioned tank walls; Using the minimization of the sum of the height adjustment values ​​of the measuring components as the objective function, the tank wall flatness constraint of each tank wall is combined to construct the tank wall flatness adjustment model.

8. The method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank according to claim 7, characterized in that, Establishing the tank wall flatness constraint includes: In the first direction of the tank wall, for three adjacent measuring components i, j, k, a first constraint is configured: ； In the second direction of the tank wall, for three adjacent measuring components Configure the second constraint for m and n: ； The first direction is perpendicular to the second direction; z i z j z k These represent the Z-axis coordinates of measurement components i, j, and k in the tank wall coordinate system after height adjustment; x i x j x k These are the coordinates of measuring components i, j, and k along the first direction in the tank wall coordinate system after height adjustment; z l z m z n These represent the Z-axis coordinates of the measuring components l, m, and n in the tank wall coordinate system after height adjustment; y l y m y n These are the coordinates of the measuring components l, m, and n along the second direction in the tank wall coordinate system after height adjustment; A is the tank wall flatness tolerance.

9. The method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank according to claim 7, characterized in that, The objective function is configured as follows: ； M represents the total number of tank walls; Nm represents the total number of measuring components on the m-th tank wall; This is the height adjustment value of the p-th measuring component on the m-th tank wall.

10. The method for adjusting the flatness of the tank wall of a liquefied gas storage and transportation tank according to claim 1, characterized in that, The measuring wedge is made of magnetic material and is fixed to the inner surface of the support structure by magnetic attraction; the target ball base is made of magnetic material or has magnetic components and is fixed to the mating surface of the measuring wedge by magnetic attraction.

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