A semi-underground LNG storage tank settlement monitoring system and method

Abstract

The application discloses a semi-underground LNG storage tank settlement monitoring system and method, and the system comprises a data acquisition and processing device, marking bolts, marking steel plates, a plurality of inclinometer casings and a plurality of horizontal fixed inclinometers. The traditional settlement monitoring method of the ground LNG storage tank is to periodically use a portable horizontal sliding inclinometer to complete settlement data measurement by manual operation. Compared with the traditional method, the horizontal fixed inclinometer is adopted in the application, automatic and uninterrupted data acquisition can be realized, and frequent operation of field personnel is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ocean technology, in particular to a semi-underground LNG tank settlement monitoring system and method. BACKGROUND

[0002] Due to various factors, during the construction and use of a large LNG tank, the total weight of the tank and the internal liquid is very large, which will exert a huge pressure on the pile cap and pile foundation. Over time, settlement or tilting may occur, and if settlement observation is not performed in a timely manner and appropriate measures are not taken, leakage may occur, resulting in incalculable losses.

[0003] Settlement observation is an important means of testing the safety of an LNG tank, and its purpose is to analyze whether the settlement that has occurred or will eventually occur in the tank meets the minimum reliability requirements for normal operation of the tank, so as to determine whether the in-service tank and its foundation need to be repaired and whether the tank can continue to operate.

[0004] Currently, existing LNG tanks are all in the form of above-ground tanks, and settlement data measurement is completed by manual use of a portable horizontal sliding inclinometer on a regular basis. There are no application cases for monitoring the settlement of semi-underground LNG tanks, and in order to ensure the safety of the construction and use of semi-underground LNG tanks. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a semi-underground LNG tank settlement monitoring system and method that can monitor semi-underground LNG tank settlement data in real time.

[0006] To solve the above technical problem, the present application provides a semi-underground LNG tank settlement monitoring system, comprising a data acquisition and processing device, marker bolts, marker steel plates, a plurality of inclinometer guide pipes and a plurality of horizontal fixed inclinometers, the inclinometer guide pipes are installed between the upper and lower surfaces of the pile cap, the inclinometers are installed in the guide pipes and connected to the data acquisition and processing device through a cable, the marker bolts are evenly arranged circumferentially on the upper surface edge of the pile cap as settlement observation points for the edge of the pile cap during construction, and the marker steel plates are evenly arranged circumferentially on the outer wall of the tank as settlement observation points for the LNG tank after earthwork backfilling.

[0007] Further, the horizontal fixed inclinometer is installed in the inclinometer guide pipe, and the horizontal fixed inclinometer is composed of a plurality of inclinometer sensors, an intermediate pulley set, a bottom pulley set, an orifice fixing assembly and a connecting pipe.

[0008] Furthermore, the end of the inclinometer guide tube is closed, the bottom pulley group presses against the end of the inclinometer guide tube, a connecting rod and the inclinometer sensor are provided between the bottom pulley group and the middle pulley group, and only a connecting rod is provided between the middle pulley group furthest from the end of the inclinometer guide tube and the orifice fixing assembly.

[0009] Furthermore, the inclinometer conduit includes a horizontal pipe and a vertical pipe that are connected together. The horizontal fixed inclinometer is installed in the horizontal pipe, and the cable located in the vertical pipe connects the horizontal fixed inclinometer to the data acquisition and processing device.

[0010] Furthermore, it also includes a total station, wherein the number of the marking bolts is the same as the number of the marking steel plates, the number is a multiple of 4, and there are no fewer than 4 of them. The total station can determine whether the storage tank has sunk by using the marking steel plates.

[0011] Furthermore, the data acquisition and processing device includes a data receiving module, a data processing module, a display module, a storage module, and a power supply module;

[0012] The power module provides power to the data acquisition and processing device, and also provides working power to the horizontal fixed inclinometer through the cable.

[0013] The data receiving module receives the tilt signal measured by the inclinometer sensor through the cable and transmits the signal to the data processing module;

[0014] The data processing module calculates and processes the tilt signal. By analyzing the tilt data of each point within the edge of the foundation and combining it with the height change of the inclinometer guide tube, it can determine whether uneven settlement has occurred at the foundation and the bottom of the tank.

[0015] The data processing module sends the processed data results to the display module and the storage module for real-time display and storage.

[0016] Furthermore, the display module is equipped with a visual monitoring system and a time calibration function, which is used to display the settlement tilt and alarm status of the LNG storage tank in real time based on the received settlement calculation results and alarm signals.

[0017] A method for monitoring the settlement of a semi-underground LNG storage tank based on the system described above is implemented through the following steps:

[0018] S1 is equipped with a semi-underground LNG storage tank settlement monitoring system, which includes marker bolts, marker steel plates, a total station, inclinometer guide pipes, a horizontal fixed inclinometer, a dedicated control cable, and a data acquisition device. The data acquisition device includes a data receiving module, a data processing module, a display module, a storage module, and a power supply module.

[0019] After marking bolts and marking steel plates were installed on the upper surface edge of the foundation and the outer side of the tank wall, S2 used a total station to record the settlement and tilt of the foundation edge and the entire tank during construction and backfilling.

[0020] S3 installs a horizontal fixed inclinometer inside the inclinometer guide tube. The inclinometer sensor detects tilt and temperature changes inside the inclinometer guide tube. The measured data is transmitted to the data receiving module in the data acquisition device in the form of an electrical signal through a dedicated control cable.

[0021] The data receiving module in the S4 data acquisition device packages and organizes the tilt signal and temperature signal and sends them to the data processing module.

[0022] In the S5 data processing module, the settlement calculation unit first performs settlement calculation on the tilt signal to obtain the initial tilt measurement value, and then sends it to the temperature compensation unit in combination with the temperature signal.

[0023] In the S6 data processing module, the temperature compensation unit first analyzes the received temperature signal to obtain the temperature measurement value, and then performs temperature compensation calculation in combination with the received initial tilt measurement value to obtain the final tilt measurement value, which is then sent to the settlement alarm unit.

[0024] In the S7 data processing module, the settlement alarm unit generates an alarm signal based on the received final tilt measurement value, and sends the final tilt measurement value and alarm signal to the display module and storage module for display and storage.

[0025] 10. A semi-underground LNG storage tank settlement monitoring method as described in claim 8, characterized in that: in step 7, the settlement alarm unit generates an alarm signal based on the received final tilt measurement value, mainly including the following steps:

[0026] ① The absolute tilt alarm module compares the final tilt measurement value received from each measurement point with the preset tilt alarm threshold. If the final tilt measurement value of the measurement point is higher than the tilt alarm threshold, an alarm signal is generated based on the position of the inclinometer sensor at that measurement point and sent to the display module and the storage module.

[0027] ② The tilt change rate alarm module calculates the tilt change rate based on the final tilt measurement values ​​received at different times from each measurement point, and compares the tilt change rate of each measurement point with the preset tilt change rate alarm threshold. When the tilt change rate of a measurement point is greater than the preset tilt change rate threshold, an alarm signal is generated based on the position of the inclinometer sensor at that measurement point and sent to the display module and storage module.

[0028] The technical effects of this invention are as follows:

[0029] 1. In contrast to the traditional method of manually measuring the settlement of above-ground LNG storage tanks using a portable horizontal sliding inclinometer, this invention employs a fixed horizontal inclinometer and data acquisition and processing device, enabling automatic and uninterrupted data acquisition. This avoids frequent on-site operations and is applicable not only to above-ground LNG storage tanks but also to semi-underground LNG storage tanks, thus filling the gap in settlement monitoring for semi-underground LNG storage tanks.

[0030] 2. This invention embeds the inclinometer guide tube between the upper and lower surfaces of the foundation, perpendicular to each other, and the intersection of their projections is located at the center of the LNG storage tank. This allows for the acquisition of settlement and tilt data at various points within the edge of the foundation, thus improving the comprehensiveness and effectiveness of the horizontal fixed inclinometer monitoring.

[0031] 3. This invention combines a total station with a horizontal fixed inclinometer, which can obtain the settlement and tilt of the semi-underground LNG storage tank at all times during construction, earthwork backfilling, and tank operation, greatly improving the safety factor of tank construction and use. Attached Figure Description

[0032] Figure 1 This is a side view of a semi-underground LNG storage tank settlement monitoring system provided by the present invention.

[0033] Figure 2 This is a top view of an observation point in a semi-underground LNG storage tank settlement monitoring system provided by the present invention.

[0034] Figure 3 This is a top view of the inclinometer guide tube layout in a semi-underground LNG storage tank settlement monitoring system provided by the present invention.

[0035] Figure 4 This is a cross-sectional view of the inclined conduit installation in a semi-underground LNG storage tank settlement monitoring system provided by the present invention.

[0036] Figure 5 This invention provides a schematic diagram of the installation of a horizontal inclinometer in a semi-underground LNG storage tank settlement monitoring system.

[0037] Figure 6 This is a schematic diagram of the data acquisition and processing device in a semi-underground LNG storage tank settlement monitoring system provided by the present invention. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0039] This invention provides a semi-underground LNG storage tank settlement monitoring system, combined withFigures 1 to 6 The device includes a marking bolt 101, a marking steel plate 102, a total station 103, a horizontal fixed inclinometer 104, a cable 105, an inclinometer guide tube 106, and a data acquisition and processing device 107.

[0040] The LNG storage tank 108 is located on a reinforced concrete foundation 109, which is supported by several reinforced concrete piles 110. The lower part of the LNG storage tank 108, the foundation 109 and the piles 110 are all below the ground 111, while the upper part of the LNG storage tank 108 is above the ground 111.

[0041] like Figure 1 As shown, the pier 109 is cylindrical, and its diameter is larger than that of the LNG storage tank 108. The LNG storage tank 108 is located in the middle of the pier 109, and the central axes of the two coincide, which can effectively balance the pressure of the LNG storage tank 108 and avoid the pier 109 from settling and tilting too quickly.

[0042] like Figure 1 and Figure 2 As shown, 20 marking bolts 101 are uniformly embedded circumferentially along the upper surface edge of the foundation 109, and 20 marking steel plates 102 are uniformly arranged circumferentially along the outer wall of the tank wall 112. After backfilling, the marking steel plates 102 are all located above the ground 111. The marking bolts 101 are uniformly arranged circumferentially along the upper surface edge of the foundation as settlement observation points at the edge of the foundation during construction, and the marking steel plates 102 are uniformly arranged circumferentially along the outer wall of the tank as settlement observation points for the LNG tank after backfilling.

[0043] During construction and after backfilling, the elevation of these monitoring points can be monitored using a total station 103. The elevation can be compared with the previous elevation to determine whether it has changed or is the same as the elevation of other points, thereby determining the overall settlement and tilt of the edge of the foundation 109 and the LNG storage tank 108.

[0044] like Figure 3 and Figure 4 As shown, the inclinometer conduit 201 is a straight pipe. Two inclinometer conduits 201 are horizontally buried at different heights between the upper and lower surfaces of the support platform 109, and are simultaneously arranged in two directions: 0 degrees / 180 degrees and 90 degrees / 270 degrees, perpendicular to each other. The intersection of their projections is located at the center of the LNG storage tank 108. The end port 306 of the inclinometer conduit 201 is sealed, and the beginning port 307 is sealed with explosion-proof putty. The inclinometer conduit 201 includes a connected horizontal pipe and a vertical pipe. The horizontal fixed inclinometer 104 is installed in the horizontal pipe, and the cable 105 located in the vertical pipe connects the horizontal fixed inclinometer 104 to the data acquisition and processing device 107.

[0045] like Figure 5As shown, the horizontal fixed inclinometer 104 consists of an inclinometer sensor 301, an intermediate pulley group 302, a bottom pulley group 303, an orifice fixing component 304, and a connecting pipe 305. The installation of the horizontal fixed inclinometer 104 is synchronized with the inclinometer guide tube 201. Installation of the horizontal fixed inclinometer 104 begins with the bottom pulley group 303, which presses against the end of the inclinometer guide tube 201 and connects to the corresponding connector and connecting pipe 305. Then, the inclinometer sensor 301 and the intermediate pulley group 302 are connected in a cyclical manner. The intermediate pulley group 302, furthest from the end of the inclinometer guide tube 201, is connected to the orifice fixing component 304 only by a connecting rod. After the first section of the horizontal fixed inclinometer 104 is installed, it is inserted into the first section of the inclinometer guide tube 201. The remaining installation involves first installing the horizontal fixed inclinometer 104, and then fitting the inclinometer guide tube 201 into it. Each set of horizontal fixed inclinometers 104 is equipped with only one bottom pulley group 303. The number of inclinometer sensors 301 and the number of intermediate pulley groups 302 are the same. After the inclinometer sensors 301 and intermediate pulley groups 302 required for the last section are installed, the hole fixing component 304 is connected to constrain the entire horizontal fixed inclinometer 104 from sliding to the bottom of the hole.

[0046] Preferably, each inclinometer guide tube 201 contains no more than 12 inclinometer sensors 301. In this embodiment, the number of inclinometer sensors 301 is 2.

[0047] like Figure 5 As shown, the data acquisition and processing device 107 is connected to the horizontal fixed inclinometer 104 via cable 105.

[0048] like Figure 6 As shown, the data acquisition and processing device 107 includes a data receiving module 401, a data processing module 402, a display module 403, a storage module 404, and a power supply module 405. The power supply module 405 provides power to the data acquisition and processing device 107 and also provides operating power to the inclinometer sensor 301 via cable 105. The data receiving module 401 receives the tilt signal measured by the inclinometer sensor 301 via cable 105 and transmits the signal to the data processing module 402. The data processing module 402 performs calculations on the tilt signal and, by analyzing the height change of the inclinometer guide tube 201, can determine whether uneven settlement has occurred at various points within the edge of the pier 109 and at the bottom of the LNG storage tank 108. The data processing module 402 sends the calculated data results to the display module 403 and the storage module 405 for real-time display and storage.

[0049] Based on the aforementioned semi-underground LNG storage tank settlement monitoring system, the present invention also provides a method for monitoring the settlement of a semi-underground LNG storage tank, characterized by comprising the following steps:

[0050] After marking bolts and marking steel plates are installed on the upper surface edge of S1 pier 109 and the outer side 112 of the tank wall, the settlement and tilt of the edge of pier 109 and the entire tank 108 are recorded using a total station 103 during construction and backfilling.

[0051] S2 installs a horizontal fixed inclinometer 104 inside the inclinometer guide tube 201. The inclinometer sensor 301 detects tilt and temperature changes inside the inclinometer guide tube 201. The measured data is transmitted to the data acquisition and processing device 107 in the form of an electrical signal via a dedicated control cable 105.

[0052] In the S3 data acquisition and processing device, the data receiving module 401 of 107 packages and organizes the tilt signal and temperature signal and sends them to the data processing module 402.

[0053] In the S4 data processing module 402, the settlement calculation unit 410 first analyzes and calculates the tilt signal to obtain the initial tilt measurement value, and then sends it to the temperature compensation unit 411 in combination with the temperature signal.

[0054] In the S5 data processing module 402, the temperature compensation unit 411 first analyzes the received temperature signal to obtain the temperature measurement value, and then performs temperature compensation calculation in combination with the received initial tilt measurement value to obtain the final tilt measurement value, which is then sent to the settlement alarm unit 412.

[0055] In the S6 data processing module 402, the settlement alarm unit 412 generates an alarm signal based on the received final tilt measurement value, and sends the final tilt measurement value and alarm signal to the display module 403 and the storage module 405 for real-time display and storage.

[0056] The settlement alarm unit generates an alarm signal based on the received final tilt measurement value, mainly including the following steps:

[0057] The S71 absolute tilt alarm module compares the final tilt measurement value received from each measurement point with the preset tilt alarm threshold. If the final tilt measurement value of the measurement point is higher than the tilt alarm threshold, an alarm signal is generated based on the position of the inclinometer sensor at that measurement point and sent to the display module and the storage module.

[0058] The S72 tilt change rate alarm module calculates the tilt change rate based on the final tilt measurement values ​​received at different times from each measurement point, and compares the tilt change rate of each measurement point with the preset tilt change rate alarm threshold. When the tilt change rate of a measurement point is greater than the preset tilt change rate threshold, an alarm signal is generated based on the position of the inclinometer sensor at that measurement point and sent to the display module and storage module.

[0059] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A method for monitoring the settlement of a semi-underground LNG storage tank based on a semi-underground LNG storage tank settlement monitoring system, characterized in that, The monitoring system includes a data acquisition and processing device, marking bolts, marking steel plates, several inclinometer guide pipes, and several horizontally fixed inclinometers. The inclinometer guide pipes are installed between the upper and lower surfaces of the foundation platform. The inclinometers are installed inside the guide pipes and connected to the data acquisition and processing device via cables. The marking bolts are evenly and circumferentially arranged along the edge of the upper surface of the foundation platform, serving as settlement observation points along the edge of the foundation platform during construction. The marking steel plates are evenly and circumferentially arranged along the outer wall of the storage tank, serving as settlement observation points for the LNG storage tank after backfilling. The horizontally fixed inclinometers are installed inside the inclinometer guide pipes. The horizontal fixed inclinometer consists of multiple sets of inclinometer sensors, a middle pulley group, a bottom pulley group, an orifice fixing assembly, and connecting pipes. The inclinometer guide tube includes a horizontal pipe and a vertical pipe that are connected. The horizontal fixed inclinometer is located on the horizontal pipe, and a cable located on the vertical pipe connects the horizontal fixed inclinometer to the data acquisition and processing device. It also includes a total station, which can determine whether the storage tank has sunk by using the marking steel plate. The data acquisition and processing device includes a data receiving module, a data processing module, a display module, a storage module, and a power supply module. The power module provides power to the data acquisition and processing device, and also provides working power to the horizontal fixed inclinometer through the cable. The data receiving module receives the tilt signal measured by the inclinometer sensor through the cable and transmits the signal to the data processing module; The data processing module calculates and processes the tilt signal. By analyzing the tilt data of each point within the edge of the foundation and combining it with the height change of the inclinometer guide tube, it can determine whether uneven settlement has occurred at the foundation and the bottom of the tank. The data processing module sends the processed data results to the display module and the storage module for real-time display and storage. The monitoring method includes the following steps: S1 is equipped with a semi-underground LNG storage tank settlement monitoring system, which includes marking bolts, marking steel plates, total station, inclinometer guide tube, horizontal fixed inclinometer, dedicated control cable, and data acquisition device; The data acquisition device includes a data receiving module, a data processing module, a display module, a storage module, and a power supply module; After marking bolts and marking steel plates were installed on the upper surface edge of the foundation and the outer side of the tank wall, S2 used a total station to record the settlement and tilt of the foundation edge and the entire tank during construction and backfilling. S3 installs a horizontally fixed inclinometer inside the inclinometer guide tube. The inclinometer sensor detects tilt and temperature changes inside the inclinometer guide tube. The measured data is transmitted to the data receiving module in the data acquisition device in the form of an electrical signal through a dedicated control cable. The data receiving module in the S4 data acquisition device packages and organizes the tilt signal and temperature signal and sends them to the data processing module. In the S5 data processing module, the settlement calculation unit first performs settlement calculation on the tilt signal to obtain the initial tilt measurement value, and then sends it to the temperature compensation unit in combination with the temperature signal. In the S6 data processing module, the temperature compensation unit first analyzes the received temperature signal to obtain the temperature measurement value, and then performs temperature compensation calculation in combination with the received initial tilt measurement value to obtain the final tilt measurement value, which is then sent to the settlement alarm unit. In the S7 data processing module, the settlement alarm unit generates an alarm signal based on the received final tilt measurement value, and sends the final tilt measurement value and alarm signal to the display module and storage module for display and storage.

2. The semi-underground LNG storage tank settlement monitoring method as described in claim 1, characterized in that: The inclinometer guide tube is closed at the end, the bottom pulley group is pressed against the end of the inclinometer guide tube, a connecting rod and the inclinometer sensor are provided between the bottom pulley group and the middle pulley group, and only a connecting rod is provided between the middle pulley group farthest from the end of the inclinometer guide tube and the orifice fixing assembly.

3. The semi-underground LNG storage tank settlement monitoring method as described in claim 1, characterized in that: The number of marking bolts is the same as the number of marking steel plates, the number is a multiple of 4, and there are no fewer than 4 of them.

4. The method for monitoring the settlement of semi-underground LNG storage tanks as described in claim 1, characterized in that: The display module is equipped with a visual monitoring system and a time calibration function, which is used to display the settlement tilt and alarm status of the LNG storage tank in real time based on the received settlement calculation results and alarm signals.

5. The method for monitoring the settlement of semi-underground LNG storage tanks as described in claim 1, characterized in that: In step 7, the settlement alarm unit generates an alarm signal based on the received final tilt measurement value, which mainly includes the following steps: ① The absolute tilt alarm module compares the final tilt measurement value received from each measurement point with the preset tilt alarm threshold. If the final tilt measurement value of the measurement point is higher than the tilt alarm threshold, an alarm signal is generated based on the position of the inclinometer sensor at that measurement point and sent to the display module and the storage module. ② The tilt change rate alarm module calculates the tilt change rate based on the final tilt measurement values ​​received at different times from each measurement point, and compares the tilt change rate of each measurement point with the preset tilt change rate alarm threshold. When the tilt change rate of a measurement point is greater than the preset tilt change rate threshold, an alarm signal is generated based on the position of the inclinometer sensor at that measurement point and sent to the display module and storage module.

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