Assembly type tank body upside-down construction method

Abstract

The invention discloses an assembly type tank body upside-down construction method, and belongs to the technical field of tank body construction. Comprising the following steps; the method comprises the steps that S1, foundation inspection and paying-off are conducted, specifically, firstly, the axis position and the elevation of a foundation are accurately measured through a total station, then foundation axis paying-off operation is conducted, oil return channels of a hydraulic system are additionally arranged, the oil return speed is increased, a speed regulating valve is installed in a hydraulic loop, then the oil return flow is regulated according to needs, a jack can stably and rapidly fall back, and the jack can return to the foundation; the pressure compensation device is installed, and the pressure of the hydraulic system is monitored and adjusted in real time in the falling process of the tank body, so that it can be ensured that the pressure is stable in the falling process of the jacking device, the situation that the jack is clamped or falls back difficultly due to pressure fluctuation is avoided, the difficulty of adjusting the circular seam assembling gap during circular seam assembling is lowered, and the assembling efficiency is improved. And the working efficiency is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of tank construction, and more specifically to an assembled tank inverted construction method. Background Art

[0002] With the rapid development of my country's economic construction and the continuous improvement of people's living standards, my country's oil consumption has increased year by year. According to statistics, my country's annual oil consumption has reached about 500 million tons in 2012. Therefore, a large number of crude oil storage tanks and refined oil storage tanks are being built and will continue to be built all over the country. Oil storage tanks are special storage equipment for crude oil and refined oil, and are the main link in oil storage construction. At present, the oil storage tanks built in my country are mainly ground oil tanks, and most of them are vertical cylindrical metal structures.

[0003] At present, there are two ways to assemble oil pipes. One is the upright method, which is carried out from bottom to top. It requires workers to work at a high position, which increases the risk of high-altitude operations. The other is the inverted method, which is carried out from top to bottom, and the working surface is concentrated on the bottom layer, reducing the risk of high-altitude operations. The board wall is then lifted by a loose-card hydraulic jack and lifted to the top. At this time, during the lifting process, if the horizontality of the board wall deviates, the hydraulic jack will be stuck or difficult to fall back due to pressure fluctuations when it falls back, resulting in easy lifting and difficult falling back. This makes it more difficult to adjust the gap between the annular seams during the annular seam assembly, increases the difficulty of construction, and reduces work efficiency. Summary of the invention

[0004] The object of the present invention is to provide an assembled tank inverted installation method to solve the problems raised in the above background technology.

[0005] An assembled tank inverted installation method, the assembled tank inverted installation method comprising the following steps: S1. Foundation inspection and layout: First, use a total station to accurately measure the axis position and elevation of the foundation, and then perform foundation axis layout operations; S2. Cutting and prefabrication: layout the base plate, wall plate and arch according to the construction drawings and sheet materials, then cut the materials using the reference line method and control the error of cutting; S3. Tank bottom installation: Install in pairs according to the structure of the tank bottom; S4, staged lifting: After the tank bottom assembly is completed, the tank body assembly will be installed. At this time, the tank body lifting process will be divided into several stages, and each stage will be paused after lifting a certain height, and the operation of the lifting system and the status of the tank body will be checked; S5, tank body assembly and installation: according to the graded stages, the tank top and the first circle wall plate are installed until the first circle wall plate is installed and the upper circle wall plate is formed, and then the tank top is hoisted as a whole to the uppermost circle wall plate for installation and welding; S6. Falling back adjustment: During the installation of the tank body, after a circle of the tank body wall plate is lifted to a certain height for assembly and welding, if the overall levelness deviation of the lifted tank body is large, it is necessary to fall back and adjust the lifting tank body, and adjust the overall levelness of the lifted tank body until the tank body is restored to the level; S7. Installation of lower wall panels and pneumatic lifting: surround the lower wall panels tightly against the upper wall panels, leaving a gap, weld the outer sides of the other longitudinal seams of the wall panels, install locking chains at both ends of the gap, then tighten the locking chains at the gap, turn on the blower, and lift the tank body with pneumatic lifting. When it reaches the predetermined height, adjust the air volume to keep the raised tank body in a suspended state, adjust and assemble the upper and lower wall panels, and weld the wall panels. Finally, repeat this process until the wall panels are installed, and then install other components until the tank body is formed.

[0006] The baseline method is a measurement and positioning method widely used in many fields. It is based on one or more known baselines and determines the position of the target point or locates and monitors the target by measuring the relative position relationship between the target point and the baseline.

[0007] Preferably, the S1 further comprises the following steps: S1-1. Foundation inspection: Check the deviation of the foundation center position, and make the deviation value no more than ±10 mm, then measure the elevation deviation of each plane of the foundation, and the deviation value no more than ±10 mm, then check the inner diameter deviation of the annular load-bearing beam foundation no more than ±10 mm, and make the flatness height difference of its surface along the circumference of the tank wall no more than 10 mm, and make the outer diameter circumference ellipticity deviation no more than 20 mm, finally set 4 permanent foundation settlement observation points evenly distributed around the foundation; S1-2. Foundation axis line laying: Taking the control points in the control network as the reference, use the total station and the polar coordinate method to measure and lay out the main axis of the foundation, and then set the axis control pile at a stable position on the edge of the foundation and fix it with concrete as the axis reference for subsequent construction; S1-3. Foundation edge and detail layout: Based on the main axis of the foundation, use a steel ruler and ink fountain tool to pop up the foundation edge and detail contour lines, such as the column foot edge and foundation beam edge, according to the design dimensions; The specific steps of the polar coordinate method Collect data: Collect the existing control survey results of the survey area, including the coordinates and elevation of the control points, as well as the topographic data of the survey area; Instruments and equipment: prepare total station, theodolite and rangefinder measuring instruments, and inspect and calibrate the instruments to ensure that the measuring accuracy meets the requirements; Select the measuring station: Set up the measuring station at the known control point. The measuring station should have a wide field of view, be able to see the measuring point, and the surrounding environment should have little interference with the measurement. Centering and leveling: Use the instrument ground centering device to accurately center the instrument on a known control point, and adjust the foot screws to center the instrument level bubble to achieve leveling of the instrument; Orientation: Find another known control point, set the instrument's horizontal circle reading to the azimuth of the known edge, and complete the instrument's orientation; Measuring angle: aim at the point to be measured and read the angle value on the horizontal disk, which is the horizontal angle between the measuring station and the point to be measured; Measuring distance: Use the distance measuring function of a distance meter or total station to measure the horizontal distance between the measuring station and the point to be measured; Calculate azimuth: Calculate the azimuth between the measuring station and the point to be measured based on the coordinates of the known control points and the measured horizontal angle; Calculate the coordinate increment: According to the measured distance and azimuth, calculate the coordinate increment Δx and Δy of the measured point relative to the measuring station. The calculation formula is Δx=Dcosa, where D is the measured distance and a is the azimuth. Calculate the coordinates of the point to be measured: Calculate the coordinates of the point to be measured based on the known coordinates of the measuring station and the calculated coordinate increment. The calculation formula is x P =x A +Δx,y P =y A +Δy, where (x A ,y A） is the station coordinate, (x P ,y P） is the coordinate of the point to be measured; Record data: record the measurement data and calculation results in detail in the measurement notebook, including the measurement station information, measurement angle, distance, and calculated coordinates; Sketching: Draw a sketch of the measurement area based on the measurement results, marking the locations of the measurement stations and points to be measured and related measurement data; Inspection and review: Check and review the measurement data and calculation results to ensure the accuracy and reliability of the measurement results.

[0008] Preferably, the S2 further comprises the following steps: S2-1. Classification and stacking: prefabrication of materials shall be carried out in the order of installation, and classified, stacked and marked; S2-2. Control the cutting error: The plate is cut by a combination of semi-automatic gas cutting and manual gas cutting. The profile is cut by a grinder, and the slag and burrs are removed after cutting. Then the cutting error is controlled, such as the groove ≦±2°, the length ≦±1mm, the diagonal length ≦±2mm. The curved plate is stacked on the jig after the arc is qualified, and it is well marked.

[0009] Preferably, the S3 further comprises the following steps: S3-1, the first type of assembly installation: if the tank bottom is a cone bottom, the base ring is prefabricated and positioned with the cone bottom and welded, and when positioning, the weld is staggered; S3-2, the second type of assembly installation: if the tank bottom is flat without edge plate, do not weld after the tank bottom plate positioning spot welding, and weld the bottom plate after the fillet welds between the tank wall and the tank bottom are welded; S3-3. The third type of installation: If the tank bottom is flat with edge plates, the tank bottom plate is spot welded and then the middle plate is welded. After the fillet welds between the tank wall and the tank bottom are welded, the welds between the edge plate and the middle plate are welded. Finally, a certain type of installation is selected according to the structural form of the tank bottom until the tank bottom is installed.

[0010] Preferably, the S4 further comprises the following steps: S4-1, Gradual operation: Before installing the tank, adopt the method of graded lifting, divide the tank lifting process into several stages, and pause after lifting to a certain height in each stage to check the operation of the lifting system and the state of the tank, and ensure the synchronization of each lifting point and the stability of the tank; S4-2, Real-time monitoring: During the process of tank lifting, the displacement sensors and pressure sensors installed at each lifting point are used to detect the lifting height and force conditions in real time, and the detection data is transmitted to the control system in real time; S4-3, Synchronous adjustment: The control system automatically compares the lifting height and force conditions of each lifting point based on real-time monitoring data. When it is found that the deviation between a certain lifting point and other lifting points exceeds the set value, the lifting equipment of the lifting point is immediately adjusted; S4-4. Manual intervention: arrange professional personnel to observe the lifting of the tank on site and compare it with the monitoring data of the control system. If any abnormal situation that the control system cannot handle in time is found, the operator should immediately take manual intervention measures, suspend the lifting operation, check the equipment and connecting parts, and continue lifting after troubleshooting.

[0011] Preferably, the S5 further comprises the following steps: S5-1. Installation of the top wall panel: When installing the tank body, install the positioning device of the top wall panel on the edge plate of the tank bottom according to the design requirements, and lift the prefabricated top wall panels piece by piece to the positioning device, assemble and weld them, and form the top wall panel; S5-2, tank top installation: After the welding of the top circle of wall panels is completed, the tank top support structure and center column are installed, and the prefabricated tank top is hoisted as a whole to the top circle of wall panels for installation and welding.

[0012] Preferably, the S6 further comprises the following steps: S6-1. Personnel training and explanation: Organize professional training for personnel involved in the construction to make them familiar with the process flow, operation methods and safety precautions of the fallback construction. Then, before the tank construction, the technicians shall give detailed technical explanations to the operators to ensure that everyone is clear about their job responsibilities and operation points; S6-2. Optimize the hydraulic system: increase the oil return passage of the hydraulic system, increase the oil return speed, and install a speed regulating valve in the hydraulic circuit, and then adjust the oil return flow as needed so that the jack can fall back smoothly and quickly. Then, by installing a pressure compensation device, during the tank falling back process, the pressure of the hydraulic system is monitored and adjusted in real time to ensure stable pressure and avoid the jack being stuck or difficult to fall back due to pressure fluctuations; S6-3. Slow and even fall: During the process of lifting the tank, if it needs to fall back, try to fall back at a very low speed, and observe the overall state of the tank and the stress conditions of each lifting point. After confirming that there is no error, fall back slowly and evenly at the predetermined speed, and the speed is controlled at 5-10cm / min; S6-4, Monitoring and Adjustment: During the fallback process, the horizontality, verticality, force and displacement of the tank body, and each lifting point are monitored in real time through sensors and monitoring instruments installed at each lifting point. Once abnormal data is found, the fallback is stopped immediately, the cause is analyzed and adjustments are made. At the same time, the monitoring personnel must feed back the detection data to the command personnel at any time so that timely decisions can be made; S6-5. Adjustment measures: If it is found that the tank body has local tilt or height difference during the lowering process, it can be corrected by adjusting the height of the corresponding lifting point separately. For the hydraulic lifting system, the height of the lifting point can be controlled by adjusting the oil volume of a single hydraulic jack; for the electric lifting system, it can be achieved by adjusting the speed or stroke of the motor; if the overall horizontality deviation of the tank body is large, all lifting points need to be adjusted uniformly.

[0013] Preferably, the S7 further comprises the following steps: S7-1, the next circle of wall panels and assembly: the prefabricated next circle of wall panels are hoisted to the surrounding of the installed tank body, and the panels are assembled. When assembling, the gap and misalignment between the wall panels and the previous circle of wall panels are controlled, and temporary supports and clamps are used for fixing; S7-2. Lift the tank body: Start the lifting device and slowly lift the tank body. The lifting speed is controlled at 5-10cm / min. During the lifting process, closely observe the rising of the tank body. Through the sensors and monitoring instruments installed at the lifting points, monitor the force and displacement of each lifting point in real time to ensure the smooth rising of the tank body. If the tank body is found to be tilted or the lifting is not synchronized, stop lifting immediately and make adjustments. When the tank body is lifted to the predetermined height, stop lifting, adjust the position of the wall panel, and weld the longitudinal and circumferential seams of the wall panel. Finally, follow the above steps to install, lift and weld the wall panels circle by circle until all wall panels are installed.

[0014] Compared with the prior art, the advantages of the present invention are: (1) In the present invention, by increasing the oil return passage of the hydraulic system, increasing the oil return speed, installing a speed regulating valve in the hydraulic circuit, and then adjusting the oil return flow rate as needed, the jack can be smoothly and quickly lowered. Then, by installing a pressure compensation device, the pressure of the hydraulic system is monitored and adjusted in real time during the tank body lowering process. In this way, the pressure can be ensured to be stable during the lowering process of the jacking device, avoiding the jack being stuck or difficult to lower due to pressure fluctuations, thereby reducing the difficulty of adjusting the gap between the annular seams during the annular seam assembly, thereby improving work efficiency.

[0015] (2) In the present invention, before installing the tank, a graded lifting method is adopted to divide the tank lifting process into several stages. After each stage is lifted to a certain height, the lifting system is paused to check the operation of the lifting system and the state of the tank to ensure the synchronization of each lifting point and the stability of the tank. Then, professional personnel are arranged to observe the lifting of the tank on site and compare it with the monitoring data of the control system. If an abnormal situation that the control system fails to handle in time is found, the operator should immediately take manual intervention measures. In this way, the tank lifting process is divided into multiple stages, which can timely discover potential safety hazards of the lifting system and ensure the safety of construction personnel and equipment. Manual intervention can respond to emergencies in the shortest time, avoid further deterioration of the problem, and reduce possible losses.

[0016] (3) In the present invention, by testing the tank body at an extremely low speed and observing the state of the tank body and the stress conditions at each lifting point, problems that may occur during the falling process can be discovered in time. Slow and uniform falling can make the tank body transition smoothly during the descent process, reducing the impact on the supporting structure, foundation and surrounding facilities. The speed is controlled at 5-10 cm / min to ensure that the inertial force and other external forces on the tank body are small, preventing damage to the tank body itself and connecting parts due to sudden changes in stress, which is beneficial to protecting the integrity and structural stability of the tank body. At the same time, the slow falling speed makes it easier for on-site staff to observe the overall state of the tank body and the conditions of each lifting point more clearly, which helps to take measures in advance to avoid the expansion of problems and ensure the smooth progress of the falling operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall process of the present invention. DETAILED DESCRIPTION

[0018] Example: See Figure 1 , an assembled tank inverted construction method comprises the following steps; S1. Foundation inspection and layout: First, use a total station to accurately measure the axis position and elevation of the foundation, and then perform foundation axis layout operations; S2. Cutting and prefabrication: layout the base plate, wall plate and arch according to the construction drawings and sheet materials, then cut the materials using the reference line method and control the error of cutting; S3. Tank bottom installation: Install in pairs according to the structure of the tank bottom; S4, staged lifting: After the tank bottom assembly is completed, the tank body assembly will be installed. At this time, the tank body lifting process will be divided into several stages, and each stage will be paused after lifting a certain height, and the operation of the lifting system and the status of the tank body will be checked; S5, tank body assembly and installation: according to the graded stages, the tank top and the first circle wall plate are installed until the first circle wall plate is installed and the upper circle wall plate is formed, and then the tank top is hoisted as a whole to the uppermost circle wall plate for installation and welding; S6. Falling back adjustment: During the installation of the tank body, after a circle of the tank body wall plate is lifted to a certain height for assembly and welding, if the overall levelness deviation of the lifted tank body is large, it is necessary to fall back and adjust the lifting tank body, and adjust the overall levelness of the lifted tank body until the tank body is restored to the level; S7. Installation of lower wall panels and pneumatic lifting: surround the lower wall panels tightly against the upper wall panels, leaving a gap, weld the outer sides of the other longitudinal seams of the wall panels, install locking chains at both ends of the gap, then tighten the locking chains at the gap, turn on the blower, and lift the tank body with pneumatic lifting. When it reaches the predetermined height, adjust the air volume to keep the raised tank body in a suspended state, adjust and assemble the upper and lower wall panels, and weld the wall panels. Finally, repeat this process until the wall panels are installed, and then install other components until the tank body is formed.

[0019] The baseline method is a measurement and positioning method widely used in many fields. It is based on one or more known baselines and determines the position of the target point or locates and monitors the target by measuring the relative position relationship between the target point and the baseline.

[0020] See also Figure 1 , S1 further comprises the following steps: S1-1. Foundation inspection: Check the deviation of the foundation center position, and make the deviation value no more than ±10 mm, then measure the elevation deviation of each plane of the foundation, and the deviation value no more than ±10 mm, then check the inner diameter deviation of the annular load-bearing beam foundation no more than ±10 mm, and make the flatness height difference of its surface along the circumference of the tank wall no more than 10 mm, and make the outer diameter circumference ellipticity deviation no more than 20 mm, finally set 4 permanent foundation settlement observation points evenly distributed around the foundation; S1-2. Foundation axis line laying: Taking the control points in the control network as the reference, use the total station and the polar coordinate method to measure and lay out the main axis of the foundation, and then set the axis control pile at a stable position on the edge of the foundation and fix it with concrete as the axis reference for subsequent construction; S1-3. Foundation edge lines and detail layout: Based on the main axis of the foundation, use a steel ruler and ink fountain tool to pop up the foundation edge lines and detailed contour lines, such as the column base edge lines and foundation beam edge lines, according to the design dimensions.

[0021] See also Figure 1 , S2 further includes the following steps: S2-1. Classification and stacking: prefabrication of materials shall be carried out in the order of installation, and classified, stacked and marked; S2-2. Control the cutting error: The plate is cut by a combination of semi-automatic gas cutting and manual gas cutting. The profile is cut by a grinder, and the slag and burrs are removed after cutting. Then the cutting error is controlled, such as the groove ≦±2°, the length ≦±1mm, the diagonal length ≦±2mm. The curved plate is stacked on the jig after the arc is qualified, and it is well marked.

[0022] See also Figure 1 , S3 also includes the following steps: S3-1, the first type of assembly installation: if the tank bottom is a cone bottom, the base ring is prefabricated and positioned with the cone bottom and welded, and when positioning, the weld is staggered; S3-2, the second type of assembly installation: if the tank bottom is flat without edge plate, do not weld after the tank bottom plate positioning spot welding, and weld the bottom plate after the fillet welds between the tank wall and the tank bottom are welded; S3-3. The third type of installation: If the tank bottom is flat with edge plates, the tank bottom plate is spot welded and then the middle plate is welded. After the fillet welds between the tank wall and the tank bottom are welded, the welds between the edge plate and the middle plate are welded. Finally, a certain type of installation is selected according to the structural form of the tank bottom until the tank bottom is installed.

[0023] See also Figure 1 , S4 further includes the following steps: S4-1, Gradual operation: Before installing the tank, adopt the method of graded lifting, divide the tank lifting process into several stages, and pause after lifting to a certain height in each stage to check the operation of the lifting system and the state of the tank, ensure the synchronization of each lifting point and the stability of the tank, such as checking and adjusting every 1-2 meters of lifting; S4-2, Real-time detection: During the process of tank lifting, the displacement sensors and pressure sensors installed at each lifting point are used to detect the lifting height and force conditions in real time, and the detection data is transmitted to the control system in real time, so that the operator can grasp the lifting status at any time; S4-3, Synchronous adjustment: The control system automatically compares the lifting height and force conditions of each lifting point based on real-time monitoring data. When it is found that the deviation between a certain lifting point and other lifting points exceeds the set value, it immediately adjusts the lifting equipment of the lifting point, such as adjusting the flow of the hydraulic system or the speed of the electric hoist, to keep it synchronized with other lifting points; S4-4. Manual intervention: arrange professional personnel to observe the lifting of the tank on site and compare it with the monitoring data of the control system. If any abnormal situation is found that the control system cannot handle in time, the operator should immediately take manual intervention measures, suspend the lifting operation, check the equipment and connecting parts, and continue lifting after troubleshooting. Abnormal situations include local jamming and abnormal noise.

[0024] Specifically, before installing the tank, a graded lifting method is adopted to divide the tank lifting process into several stages. After each stage is lifted to a certain height, the lifting system is paused to check the operation of the lifting system and the status of the tank, ensure the synchronization of each lifting point and the stability of the tank, and then arrange professional personnel to observe the tank lifting situation on site and compare it with the monitoring data of the control system. If any abnormal situation that the control system fails to handle in time is found, the operator should immediately take manual intervention measures. In this way, the tank lifting process is divided into multiple stages, which can timely discover potential safety hazards of the lifting system and ensure the safety of construction personnel and equipment. Manual intervention can respond to emergencies in the shortest time, avoid further deterioration of the problem, and reduce possible losses.

[0025] See also Figure 1 , S5 further includes the following steps: S5-1. Installation of the top wall panel: When installing the tank body, the positioning device of the top wall panel is installed on the edge plate of the tank bottom according to the design requirements, and the prefabricated top wall panels are hoisted to the positioning device piece by piece, assembled and welded to form the top wall panel, and the positioning device is a positioning ring made of angle steel or channel steel; S5-2. Tank top installation: After the welding of the top circle of wall panels is completed, the supporting structure and center column of the tank top are installed, and the prefabricated tank top is hoisted as a whole to the top circle of wall panels for installation and welding. The connecting welds between the tank top and the wall panels should be tight to ensure the sealing of the tank top.

[0026] See also Figure 1 , S6 further includes the following steps: S6-1. Personnel training and explanation: Organize professional training for personnel involved in the construction to make them familiar with the process flow, operation methods and safety precautions of the fallback construction. Then, before the tank construction, the technicians shall give detailed technical explanations to the operators to ensure that everyone is clear about their job responsibilities and operation points; S6-2. Optimize the hydraulic system: increase the oil return passage of the hydraulic system, increase the oil return speed, and install a speed regulating valve in the hydraulic circuit, and then adjust the oil return flow as needed so that the jack can fall back smoothly and quickly. Then, by installing a pressure compensation device, the pressure of the hydraulic system can be monitored and adjusted in real time during the tank falling back process; S6-3. Slow and even fall: During the process of lifting the tank, if it needs to fall back, try to fall back at a very low speed, and observe the overall state of the tank and the stress conditions of each lifting point. After confirming that there is no error, fall back slowly and evenly at the predetermined speed, and the speed is controlled at 5-10cm / min; S6-4, Monitoring and Adjustment: During the fallback process, the horizontality, verticality, force and displacement of the tank body, and each lifting point are monitored in real time through sensors and monitoring instruments installed at each lifting point. Once abnormal data is found, the fallback is stopped immediately, the cause is analyzed and adjustments are made. At the same time, the monitoring personnel must feed back the detection data to the command personnel at any time so that timely decisions can be made; S6-5. Adjustment measures: If it is found that the tank body has local tilt or height difference during the falling process, it can be corrected by adjusting the height of the corresponding lifting point separately. For the hydraulic lifting system, the height of the lifting point can be controlled by adjusting the oil volume of a single hydraulic jack; for the electric lifting system, it can be achieved by adjusting the speed or stroke of the motor; if the overall horizontality deviation of the tank body is large, all lifting points need to be adjusted uniformly. First, calculate the height difference that needs to be adjusted for each lifting point, and then adjust the height of each lifting point step by step according to the principle of high first and low later to restore the tank body to the level. The pressure compensator includes a compensator, an accumulator, a pressure reducing valve, and a relief valve.

[0027] Specifically, by increasing the oil return passage of the hydraulic system, increasing the oil return speed, and installing a speed regulating valve in the hydraulic circuit, the oil return flow is adjusted as needed to allow the jack to fall back smoothly and quickly, and then by installing a pressure compensation device, the pressure of the hydraulic system is monitored and adjusted in real time during the tank falling back process. At this time, the falling back speed is controlled at 5-10cm / min. This can ensure that the pressure is stable during the falling back of the jacking device to avoid the jack being stuck or difficult to fall back due to pressure fluctuations. Then, according to the local tilt or height difference during the falling back of the tank, it can be corrected by adjusting the height of the corresponding lifting point separately. If the overall horizontality deviation of the tank is large, all lifting points need to be adjusted uniformly. This can reduce the difficulty of adjusting the gap between the annular seams during the annular seam assembly and improve work efficiency.

[0028] See also Figure 1 , S7 further includes the following steps: S7-1, the next circle of wall panels and assembly: the prefabricated next circle of wall panels are hoisted to the surrounding of the installed tank body, and the panels are assembled. When assembling, the gap and misalignment between the wall panels and the previous circle of wall panels are controlled, and temporary supports and clamps are used for fixing; S7-2. Lift the tank body: Start the lifting device and slowly lift the tank body. The lifting speed is controlled at 5-10cm / min. During the lifting process, closely observe the rising of the tank body. Through the sensors and monitoring instruments installed at the lifting points, monitor the force and displacement of each lifting point in real time to ensure the smooth rising of the tank body. If the tank body is found to be tilted or the lifting is not synchronized, stop lifting immediately and make adjustments. When the tank body is lifted to the predetermined height, stop lifting, adjust the position of the wall panel, and weld the longitudinal and circumferential seams of the wall panel. Finally, follow the above steps to install, lift and weld the wall panels circle by circle until all wall panels are installed.

[0029] Specifically, by testing the descent at an extremely low speed and observing the state of the tank and the stress conditions at each lifting point, possible problems that may arise during the descent can be discovered in a timely manner. Slow and even descent can allow the tank to transition smoothly during the descent, reducing the impact on the supporting structure, foundation and surrounding facilities. Speed ​​control at 5-10cm / min can ensure that the inertial force and other external forces on the tank are small, preventing damage to the tank itself and connecting parts due to sudden changes in force, which is beneficial to protecting the integrity and structural stability of the tank. At the same time, the slow descent speed allows on-site staff to more clearly observe the overall state of the tank and the conditions of each lifting point, which helps to take measures in advance to avoid the expansion of problems and ensure the smooth progress of the descent operation.

[0030] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for inverted assembly of an assembled tank, characterized in that: The method for inverted assembly of an assembled tank body comprises the following steps: S1. Foundation inspection and layout: First, use a total station to accurately measure the axis position and elevation of the foundation, and then perform foundation axis layout operations; S2. Cutting and prefabrication: layout the base plate, wall plate and arch according to the construction drawings and sheet materials, then cut the materials using the reference line method and control the error of cutting; S3. Tank bottom installation: Install in pairs according to the structure of the tank bottom; S4, staged lifting: After the tank bottom assembly is completed, the tank body assembly will be installed. At this time, the tank body lifting process will be divided into several stages, and each stage will be paused after lifting a certain height, and the operation of the lifting system and the status of the tank body will be checked; S5, tank body assembly and installation: according to the graded stages, the tank top and the first circle wall plate are installed until the first circle wall plate is installed and the upper circle wall plate is formed, and then the tank top is hoisted as a whole to the uppermost circle wall plate for installation and welding; S6. Falling back adjustment: During the installation of the tank body, after a circle of the tank body wall plate is lifted to a certain height for assembly and welding, if the overall levelness deviation of the lifted tank body is large, it is necessary to fall back and adjust the lifting tank body, and adjust the overall levelness of the lifted tank body until the tank body is restored to the level; S7. Installation of lower wall panels and pneumatic lifting: surround the lower wall panels tightly against the upper wall panels, leaving a gap, weld the outer sides of the other longitudinal seams of the wall panels, install locking chains at both ends of the gap, then tighten the locking chains at the gap, turn on the blower, and lift the tank body with pneumatic lifting. When it reaches the predetermined height, adjust the air volume to keep the raised tank body in a suspended state, adjust and assemble the upper and lower wall panels, and weld the wall panels. Finally, repeat this process until the wall panels are installed, and then install other components until the tank body is formed.

2. The method for inverted assembly of an assembled tank according to claim 1, characterized in that: The S1 further comprises the following steps: S1-1. Foundation inspection: Check the deviation of the foundation center position, and make the deviation value no more than ±10 mm, then measure the elevation deviation of each plane of the foundation, and the deviation value no more than ±10 mm, then check the inner diameter deviation of the annular load-bearing beam foundation no more than ±10 mm, and make the flatness height difference of its surface along the circumference of the tank wall no more than 10 mm, and make the outer diameter circumference ellipticity deviation no more than 20 mm, finally set 4 permanent foundation settlement observation points evenly distributed around the foundation; S1-2. Foundation axis line laying: Taking the control points in the control network as the reference, use the total station and the polar coordinate method to measure and lay out the main axis of the foundation, and then set the axis control pile at a stable position on the edge of the foundation and fix it with concrete as the axis reference for subsequent construction; S1-3. Foundation edge lines and detail layout: Based on the main axis of the foundation, use a steel ruler and ink fountain tool to pop up the foundation edge lines and detailed contour lines, such as the column base edge lines and foundation beam edge lines, according to the design dimensions.

3. The method for inverted assembly of an assembled tank according to claim 1, characterized in that: The S2 further comprises the following steps: S2-1. Classification and stacking: prefabrication of materials shall be carried out in the order of installation, and classified, stacked and marked; S2-2. Control the cutting error: The plate is cut by a combination of semi-automatic gas cutting and manual gas cutting. The profile is cut by a grinder, and the slag and burrs are removed after cutting. Then the cutting error is controlled, such as the groove ≦±2°, the length ≦±1mm, the diagonal length ≦±2mm. The curved plate is stacked on the jig after the arc is qualified, and it is well marked.

4. The method for inverted assembly of an assembled tank according to claim 3, characterized in that: The S3 further comprises the following steps: S3-1, the first type of pair installation: when installing the tank body, if the tank bottom is a cone bottom, the base ring is prefabricated and positioned with the cone bottom and welded, and when positioning, the weld is staggered; S3-2, the second type of assembly installation: if the tank bottom is flat without edge plate, do not weld after the tank bottom plate positioning spot welding, and weld the bottom plate after the fillet welds between the tank wall and the tank bottom are welded; S3-3. The third type of installation: If the tank bottom is flat with edge plates, the tank bottom plate is spot welded and then the middle plate is welded. After the fillet welds between the tank wall and the tank bottom are welded, the welds between the edge plate and the middle plate are welded. Finally, a certain type of installation is selected according to the structural form of the tank bottom until the tank bottom is installed.

5. The method for inverted assembly of an assembled tank according to claim 4, characterized in that: The S4 further comprises the following steps: S4-1, Gradual operation: Before installing the tank, adopt the method of graded lifting, divide the tank lifting process into several stages, and pause after lifting to a certain height in each stage to check the operation of the lifting system and the state of the tank, and ensure the synchronization of each lifting point and the stability of the tank; S4-2, Real-time monitoring: During the process of tank lifting, the displacement sensors and pressure sensors installed at each lifting point are used to detect the lifting height and force conditions in real time, and the detection data is transmitted to the control system in real time; S4-3, Synchronous adjustment: The control system automatically compares the lifting height and force conditions of each lifting point based on real-time monitoring data. When it is found that the deviation between a certain lifting point and other lifting points exceeds the set value, the lifting equipment of the lifting point is immediately adjusted; S4-4. Manual intervention: arrange professional personnel to observe the lifting of the tank on site and compare it with the monitoring data of the control system. If any abnormal situation that the control system cannot handle in time is found, the operator should immediately take manual intervention measures, suspend the lifting operation, check the equipment and connecting parts, and continue lifting after troubleshooting.

6. The method for inverted assembly of an assembled tank according to claim 1, characterized in that: The S5 further comprises the following steps: S5-1. Installation of the top wall panel: When installing the tank body, install the positioning device of the top wall panel on the edge plate of the tank bottom according to the design requirements, and lift the prefabricated top wall panels piece by piece to the positioning device, assemble and weld them, and form the top wall panel; S5-2, tank top installation: After the welding of the top circle of wall panels is completed, the tank top support structure and center column are installed, and the prefabricated tank top is hoisted as a whole to the top circle of wall panels for installation and welding.

7. The method for inverted assembly of an assembled tank according to claim 6, characterized in that: The S6 further comprises the following steps: S6-1. Personnel training and explanation: Organize professional training for personnel involved in the construction to make them familiar with the process flow, operation methods and safety precautions of the fallback construction. Then, before the tank construction, the technicians shall give detailed technical explanations to the operators to ensure that everyone is clear about their job responsibilities and operation points; S6-2. Optimize the hydraulic system: increase the oil return passage of the hydraulic system, increase the oil return speed, and install a speed regulating valve in the hydraulic circuit, and then adjust the oil return flow as needed so that the jack can fall back smoothly and quickly. Then, by installing a pressure compensation device, during the tank falling back process, the pressure of the hydraulic system is monitored and adjusted in real time to ensure stable pressure and avoid the jack being stuck or difficult to fall back due to pressure fluctuations; S6-3. Slow and even fall: During the process of lifting the tank, if it needs to fall back, try to fall back at a very low speed, and observe the overall state of the tank and the stress conditions of each lifting point. After confirming that there is no error, fall back slowly and evenly at the predetermined speed, and the speed is controlled at 5-10cm / min; S6-4, Monitoring and Adjustment: During the fallback process, the horizontality, verticality, force and displacement of the tank body, and each lifting point are monitored in real time through sensors and monitoring instruments installed at each lifting point. Once abnormal data is found, the fallback is stopped immediately, the cause is analyzed and adjustments are made. At the same time, the monitoring personnel must feed back the detection data to the command personnel at any time so that timely decisions can be made; S6-5. Adjustment measures: If it is found that the tank body has local tilt or height difference during the falling process, it can be corrected by adjusting the height of the corresponding lifting point separately; if the overall horizontal deviation of the tank body is large, all lifting points need to be adjusted uniformly.

8. The method for inverted assembly of an assembled tank according to claim 7, characterized in that: The S7 further comprises the following steps: S7-1, the next circle of wall panels and assembly: the prefabricated next circle of wall panels are hoisted to the surrounding of the installed tank body, and the panels are assembled. When assembling, the gap and misalignment between the wall panels and the previous circle of wall panels are controlled, and temporary supports and clamps are used for fixing; S7-2. Lift the tank body: Start the lifting device and slowly lift the tank body. The lifting speed should be controlled at 5-10cm / min. During the lifting process, closely observe the rising of the tank body. Through the sensors and monitoring instruments installed at the lifting points, the force and displacement of each lifting point can be monitored in real time. When the tank body is lifted to the predetermined height, stop lifting, adjust the position of the wall panel, and weld the longitudinal and circumferential seams of the wall panel. Finally, follow the above steps to install, lift and weld the wall panels circle by circle until all the wall panels are installed.

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