Grating-based foundation settlement, temperature and water seepage monitoring device and method

Abstract

The invention discloses a grating-based foundation settlement, temperature and water seepage monitoring device and method.A large cavity and a small cavity are formed in a heat conduction protection shell of a settlement and temperature real-time monitoring assembly, a one-way low-pressure oil return opening and a one-way high-pressure oil drainage opening are formed in separation faces respectively, and the large cavity is filled with heat conduction oil; a grating protection layer wrapping the settlement deformation monitoring grating is fixedly connected to the inner wall of the heat conduction protection shell. The temperature compensation gratings are wrapped with light plastic hard shells, are suspended in the heat conduction oil and are in one-to-one correspondence with the grating protection layers; the adjacent gratings are connected through conduction optical fibers; the settlement and temperature real-time monitoring assembly and the water seepage real-time monitoring assembly are respectively connected with the grating demodulator through jumpers, the grating demodulator is connected with the control end, and the control end is used for carrying out temperature compensation on data analyzed by the grating demodulator. The system is high in temperature and settlement deformation monitoring precision and high in response speed, and integrates a water seepage monitoring function.

Description

Technical Field

[0001] The present invention relates to the field of operation monitoring of the foundation of a molten salt tank for solar-thermal energy storage, and particularly to a monitoring device and method for foundation settlement, temperature, and water seepage based on a grating. Background Art

[0002] As a key component for heat storage and heat transfer in solar-thermal power generation technology, deeply understanding and solving its design and operation problems, and ensuring its safe and efficient operation are the basis for the steady development of solar-thermal power generation technology. The molten salt storage tank has a large capacity and a complex structure. Ensuring the stability and safety of the heat storage tank is an important goal of the molten salt energy storage project, and the requirements for the foundation also increase accordingly.

[0003] Currently, the deformation of the foundation material of the storage tank, the resulting uneven settlement, and the excessive thermal stress of the bottom plate caused by rainfall or rising groundwater level are the main problems affecting the stable operation of the storage tank. Therefore, the monitoring of the foundation settlement, temperature, and water seepage of the storage tank is crucial. Currently, there are relatively few monitoring technologies for the deformation of the foundation material. The foundation settlement data is mainly directly monitored through a level or a total station. Generally, both of these devices require manual setting and operation, resulting in the monitoring process being possibly affected by human factors. In addition, these two devices can only detect when the overall settlement displacement of the tank body or the foundation occurs, which is not conducive to perceiving and preventing the hazards brought by foundation settlement in advance. Accurate and sensitive temperature and settlement deformation monitoring are very important for the stable operation of the storage tank. New monitoring technologies need to be developed in the future.

[0004] Patent CN108592871A discloses a monitoring device and system for the foundation settlement of a storage tank. This device can only monitor the vertical settlement of the foundation at an external fixed position, cannot meet the detection of the internal position and uneven settlement of the molten salt tank foundation, has a certain lag, and does not have a temperature compensation device, is easily affected by external temperature changes, and has limited measurement accuracy.

[0005] Patent CN113931697A discloses a tunnel water seepage warning device and a tunnel water seepage monitoring and treatment method. This device has a shell that plays a supporting role, which will damage the foundation structure; and when the foundation undergoes uneven settlement, it may cause damage to the shell of the detection device, resulting in the failure of the internal weighing device.

[0006] In summary, the existing foundation parameter monitoring mainly focuses on single parameter monitoring. The monitoring of foundation temperature parameters is mainly carried out by installing a certain number of thermocouples or resistance thermometers. It is very difficult to install a large number of thermocouples or resistance thermometers in the tank foundation, and the installation of the two may damage the tank foundation structure and thermal insulation characteristics. The number of pre-buried thermocouples in actual solar thermal power stations is limited, which leads to a large detection area for a single thermocouple; temperature measurement may be affected by ambient environmental factors (such as humidity, pressure, corrosion, etc.), resulting in unstable measurement results; and thermocouple and thermal resistance temperature measurement technology are not sensitive enough for temperature monitoring and cannot respond quickly to tiny molten salt leaks, so a more sensitive detection method is needed. For foundation settlement data, most foundation monitoring is based on data collection when settlement occurs above the surface, which cannot directly monitor subtle changes in the foundation and lacks sensitivity; and is easily affected by other environmental factors, and the accuracy needs to be improved. As for water seepage monitoring, the existing means are insufficient and easily damage the foundation structure, and cannot meet the requirements of accurate real-time measurement of multiple parameters of the foundation when the tank is in operation. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention proposes a grating-based foundation settlement, temperature and water seepage monitoring device and method.

[0008] The specific technical solutions are as follows:

[0009] A grating-based foundation settlement, temperature and water seepage monitoring device, comprising: a settlement and temperature real-time monitoring component, a water seepage real-time monitoring component, a grating demodulator, a control terminal, and a jumper;

[0010] The settlement and temperature real-time monitoring component includes: a heat-conducting protective shell, heat-conducting oil, multiple settlement deformation monitoring gratings and grating protection layers, multiple temperature compensation gratings and a lightweight plastic hard shell, and a conductive optical fiber; the heat-conducting protective shell is a hollow structure, and has flexibility and heat conductivity; the interior of the heat-conducting protective shell is divided into a large chamber and a small chamber, and a one-way low-pressure oil return port and a one-way high-pressure oil drain port are respectively arranged on the dividing surface, and the large chamber is filled with heat-conducting oil, and can enter the small chamber through the one-way high-pressure oil drain port, and the heat conduction of the small chamber The oil can enter the large chamber through the one-way low-pressure oil return port; the outside of the settlement deformation monitoring grating is wrapped with a flexible and thermally conductive grating protection layer, and the grating protection layer is axially fixed to the inner wall of the thermally conductive protective shell; the outside of the temperature compensation grating is wrapped with a thermally conductive lightweight plastic hard shell, which is suspended in the thermal oil and corresponds to the grating protection layer in the vertical direction; adjacent settlement deformation monitoring gratings and adjacent temperature compensation gratings are connected by conductive optical fibers and transmit optical signals;

[0011] The real-time seepage monitoring component includes: a seepage deformation grating, a compressible and expandable push rod, an expansion structure, a water barrier plate, and a seepage-sensitizing rubber funnel; the seepage deformation grating is arranged in the large chamber and fixed on the partition surface between the large chamber and the small chamber; the seepage-sensitizing rubber funnel is arranged outside the heat-conducting protective shell, and openings are provided and penetrate in both the upper and lower directions; a communication channel is horizontally arranged between the central position of the seepage deformation grating and the central position of the seepage-sensitizing rubber funnel, and an expansion structure that can expand when encountering water is arranged in the communication channel; a water barrier plate is horizontally arranged on the side of the expansion structure close to the seepage-sensitizing rubber funnel to isolate the upper and lower openings, and the side close to the heat-conducting protective shell is in contact with one end of the compressible expansion rod push rod. In the initial installation state, the other end of the compressible expansion rod push rod is in contact with the seepage deformation grating and no mutual force is generated;

[0012] The settlement deformation monitoring grating and the temperature compensation grating of the settlement and temperature real-time monitoring component, and the seepage deformation grating of the seepage real-time monitoring component are respectively connected to the grating demodulator through jumpers. The grating demodulator is connected to the control end, and the control end is used to perform temperature compensation on the data analyzed by the grating demodulator to obtain the settlement deformation data and the seepage volume after temperature compensation.

[0013] Further, a plurality of the grating protective layers are sequentially and uniformly fixed on the inner wall of the heat-conducting protective shell along the axial direction by epoxy resin.

[0014] Further, the inside of the lightweight plastic hard shell is hollow, and the temperature compensation grating is fixed at the bottom of the lightweight plastic hard shell; after installing the temperature compensation grating, the gravity of the lightweight plastic shell is balanced with the buoyancy provided by the heat-conducting oil.

[0015] Further, the length of the conduction optical fiber is set with a redundancy amount to ensure that the temperature compensation grating is only affected by temperature.

[0016] Further, the seepage-sensitizing rubber funnel is made of rubber material.

[0017] Further, the device is arranged in the foundation and includes a plurality of monitoring units. Each monitoring unit includes a settlement and temperature real-time monitoring component and a seepage real-time monitoring component; the plurality of monitoring units are on the same horizontal plane and are arranged in an array; each monitoring unit is connected to the grating demodulator through a jumper, and the settlement situation of the foundation in this linear direction is analyzed according to the settlement deformation data generated at different positions in the same linear direction.

[0018] Further, the plurality of monitoring units are arranged in a circumferential array, that is, they are evenly divided into multiple groups in the circumferential direction, and multiple are evenly arranged in each group along the radial direction.

[0019] A method for monitoring foundation settlement, temperature, and seepage based on a grating, which is implemented according to the described grating-based foundation settlement, temperature, and seepage monitoring device, includes the following steps:

[0020] S1: Prepare a real-time settlement and temperature monitoring component and a real-time seepage monitoring component according to the requirements of the grating-based foundation settlement, temperature, and seepage monitoring device. The temperature compensation grating, settlement deformation monitoring grating, and seepage deformation grating are installed in a heat-conducting protective shell filled with heat-conducting oil according to the corresponding positions and connection requirements.

[0021] S2: Arrange the real-time settlement and temperature monitoring component and the real-time seepage monitoring component into the foundation. Use jumpers to connect the temperature compensation grating, settlement deformation monitoring grating, and seepage deformation grating to the grating demodulator respectively, and connect the grating demodulator to the control terminal. The grating demodulator and the control terminal are placed on the upper surface of the foundation.

[0022] S3: The grating demodulator analyzes the optical signals returned by the temperature compensation grating, settlement deformation monitoring grating, and seepage deformation grating to obtain the central wavelength drift of each grating.

[0023] S4: The grating demodulator transmits the analyzed data to the control terminal, and the control terminal performs temperature compensation: subtract the central wavelength drift of the temperature compensation grating from the central wavelength drift of the settlement deformation monitoring grating to obtain the settlement deformation after temperature compensation, so as to analyze whether there is local settlement in the foundation; subtract the central wavelength drift of the temperature compensation grating from the central wavelength drift of the seepage deformation grating to obtain the seepage expansion deformation after temperature compensation, so as to reflect the seepage situation.

[0024] The beneficial effects of the present invention are:

[0025] (1) The present invention has a fast monitoring response speed and good real-time performance for temperature and settlement deformation: adopting the fiber grating sensing technology, with high sensitivity, fast speed of collecting and transmitting information, and can realize remote real-time monitoring at the control terminal, avoiding personnel inspection and examination.

[0026] (2) The present invention has high monitoring accuracy for temperature and settlement deformation. The grating is only sensitive to settlement deformation and temperature, excluding the influence of the external environment on parameter monitoring; using temperature compensation technology, the heat-conducting protective shell is filled with heat-conducting oil to ensure uniform temperature distribution inside. The temperature compensation grating is suspended in the heat-conducting oil with a certain viscosity, and a light plastic hard shell is set outside as a protective layer to further ensure that it is not affected by deformation, which not only plays a temperature compensation function but also a temperature monitoring function to reflect the molten salt leakage situation.

[0027] (3) The present invention integrates the function of seepage monitoring, and the seepage monitoring is sensitive: the seepage monitoring part is added with a seepage - sensitizing rubber funnel with an upper and lower funnel structure, which increases the seepage area, making the seepage monitoring more sensitive under the same seepage volume, and providing reference information for the operation of the storage tank.

[0028] (4) The device of the present invention is small in volume and is protected by a heat - conducting protective shell on the outside. It is buried during the compaction process of the ceramsite soil. The survival rate of the grating for detection is high and the impact on the foundation is small. It can detect temperature, settlement, and soil layer seepage, and can realize multi - situation monitoring of the foundation. Description of the Drawings

[0029] Figure 1 It is a schematic structural diagram of the grating - based foundation settlement, temperature, and seepage monitoring device in the embodiment of the present invention.

[0030] Figure 2 It is a cross - sectional view of the grating - based foundation settlement, temperature, and seepage monitoring device in the embodiment of the present invention.

[0031] Figure 3 It is a schematic diagram of the layout position of the grating - based foundation settlement, temperature, and seepage monitoring device in the ceramsite soil layer in the embodiment of the present invention.

[0032] In the figure, heat - conducting protective shell 1, heat - conducting oil 2, settlement deformation monitoring grating 3, grating protective layer 4, epoxy resin 5, temperature - compensating grating 6, lightweight plastic hard shell 7, one - way low - pressure oil return port 8, one - way high - pressure oil drain port 9, conduction optical fiber 10; seepage deformation grating 11, compressible and expandable push rod 12, expansion structure 13, water - proof plate 14, seepage - sensitizing rubber funnel 15, grating demodulator 16, control terminal 17, jumper 18. Detailed Embodiment

[0033] The present invention will be described in detail below according to the drawings and preferred embodiments. The purpose and effect of the present invention will become more apparent. The present invention will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] As Figure 1 and Figure 2 shown, a grating - based foundation settlement, temperature, and seepage monitoring device includes: a real - time settlement and temperature monitoring component, a real - time seepage monitoring component, a grating demodulator 16, a control terminal 17, and a jumper 18.

[0035] The real - time settlement and temperature monitoring component includes: a heat - conducting protective shell 1, heat - conducting oil 2, a settlement deformation monitoring grating 3, a grating protective layer 4, epoxy resin 5, a temperature - compensating grating 6, a lightweight plastic hard shell 7, a one - way low - pressure oil return port 8, a one - way high - pressure oil drain port 9, and a conduction optical fiber 10.

[0036] Due to the small size and fragility of the grating, its safety needs to be ensured during installation under harsh conditions; the heat-conducting protective shell 1 is a hollow cylinder, which plays a role in protecting the internal grating device. When buried in the foundation, its axis is parallel to the horizontal plane, and during the compaction process, the heat-conducting protective shell 1 maintains good contact with the external soil layer; the heat-conducting protective shell 1 has good flexibility, can better transmit bending deformation, and has good heat-conducting performance, reducing the loss of temperature during the transfer process to the inside of the heat-conducting protective shell 1. The interior of the heat-conducting protective shell 1 is divided into two chambers, a large chamber and a small chamber. The large chamber is filled with heat-conducting oil 2 with good heat transfer effect. Considering that the heat-conducting oil 2 is an incompressible liquid, a one-way low-pressure oil return port 8 and a one-way high-pressure oil drain port 9 are successively arranged on the partition surface between the two chambers. When the heat-conducting protective shell 1 is not affected by external forces, that is, in the initial state, the heat-conducting oil 2 fills the large chamber, and the small chamber is an empty cavity; when the foundation settles and the heat-conducting protective shell 1 is compressed, a high pressure is generated inside the large chamber. When the pressure reaches the opening pressure of the one-way high-pressure oil drain port 9, the heat-conducting oil 2 drains to the small chamber through the one-way high-pressure oil drain port 9, avoiding the influence of high pressure on the device, so as to improve the response of the device to the deformation of the external soil layer and achieve the effect of making the heat-conducting protective shell 1 truly respond to the external deformation; when the heat-conducting oil 2 in the large chamber is insufficient and needs to return oil, when the generated pressure reaches the opening pressure of the one-way low-pressure oil return port 8, the heat-conducting oil 2 returns to the large chamber from the small chamber again through the one-way low-pressure oil return port 8, so that the large chamber always remains in a state of being filled with heat-conducting oil 2.

[0037] There are multiple settlement deformation monitoring gratings 3, and each settlement deformation monitoring grating 3 is externally wrapped with a grating protective layer 4. The grating protective layer 4 has good heat conductivity, flexibility and sealing performance, playing a role in protecting the settlement deformation monitoring grating 3. The multiple grating protective layers 4 are sequentially and uniformly fixedly connected to the inner wall of the heat-conducting protective shell 1 along the axial direction by epoxy resin 5, ensuring that the settlement deformation monitoring grating 3 and the heat-conducting protective shell 1 have good response to deformation and improving the sensitivity of detecting deformation.

[0038] The number of temperature compensation gratings 6 is the same as the number of settlement deformation monitoring gratings 3. Each temperature compensation grating 6 is externally wrapped with a light plastic hard shell 7, and the temperature compensation grating 6 is fixedly connected to the bottom of the inner wall of the light plastic hard shell 7 (in this embodiment, the connection is achieved by gluing); the light plastic hard shell 7 has certain hardness, good heat conductivity and sealing performance, playing a role in protecting the temperature compensation grating 6. The space between the temperature compensation grating 6 and the light plastic hard shell 7 is hollow, and the heat-conducting oil 2 has a certain viscosity and density, so as to generate sufficient buoyancy to balance the gravity of the light plastic hard shell 7 with the built-in temperature compensation grating 6, so that the temperature compensation grating 6 can float in the heat-conducting oil 2. Each temperature compensation grating 6 corresponds to a settlement deformation monitoring grating 3 in the vertical direction.

[0039] The lightweight plastic hard shell 7 ensures that the temperature compensation grating 6 is not affected by deformation. The heat conduction protective shell 1, the heat conduction oil 2, the grating protective layer 4, and the lightweight plastic hard shell 7 jointly reduce the loss of temperature during transmission, ensuring that all grating devices are affected by the same temperature, so that the temperature compensation grating 6 can perform temperature compensation.

[0040] Adjacent settlement deformation monitoring gratings 3 are connected by a conduction optical fiber 10 to transmit optical signals. Adjacent temperature compensation gratings 6 are also connected by a conduction optical fiber 10 to transmit optical signals, and the length of the conduction optical fiber 10 has a certain redundancy, further ensuring that the temperature compensation grating 6 is only affected by temperature and not interfered by other mechanical stresses or strains.

[0041] The real-time water seepage monitoring component includes: a water seepage deformation grating 11, a compressible and expandable push rod 12, an expansion structure 13, a water isolation plate 14, and a water seepage sensitizing rubber funnel 15.

[0042] The water seepage deformation grating 11 is arranged in the large chamber and fixed on the partition surface between the large chamber and the small chamber to ensure that it is affected by the same temperature as the temperature compensation grating 6 and the settlement deformation monitoring grating 3. In order to perform water seepage monitoring more quickly and sensitively, a water seepage sensitizing rubber funnel 15 is set on the right side outside the heat conduction protective shell 1. By increasing the water seepage collection area through the funnel, the collected water seepage volume is greatly increased under the same water seepage volume, increasing the water seepage detection sensitivity; the water seepage sensitizing rubber funnel 15 has openings in the upper and lower directions and the upper and lower openings are connected, so that the device has a sensitizing monitoring function for both the rising of groundwater (entering through the funnel opening with the opening direction downward) and the seepage of surface water (entering through the funnel opening with the opening direction upward); the material of the water seepage sensitizing rubber funnel 15 is rubber, which is impermeable, corrosion-resistant and relatively soft, avoiding damage to the foundation structure. A cylindrical channel is horizontally arranged between the central position of the water seepage deformation grating 11 and the central position of the water seepage sensitizing rubber funnel 15, and an expansion structure 13 is arranged in the cylindrical channel. The expansion structure 13 uses a water-swellable material with good expansibility. A water isolation plate 14 is horizontally arranged on the right side of the expansion structure 13 to isolate the upper and lower openings and play a role in guiding the flow direction of water seepage, so that the water seepage converges towards the expansion structure 13 instead of permeating upward or downward.

[0043] The compressible expansion push rod 12 is horizontally arranged on the left side of the expansion structure 13. In the initial installation state (when the foundation is in a dry state), the left side of the compressible expansion push rod 12 is in contact with the central position of the water seepage deformation grating 11 without any interaction force, and the right side is in contact with the expansion structure 13. When the expansion structure 13 expands when encountering water, it will push the compressible expansion push rod 12 to move leftward to achieve displacement transmission. The compressible expansion push rod 12 is compressible and acts on the water seepage deformation grating 11, causing it to be squeezed and deformed. The water seepage situation is judged by detecting the grating signal, and the speed and magnitude of the change in the grating signal also reflect the amount of water seepage to a certain extent.

[0044] Collect and process the data of the settlement and temperature real-time monitoring component and the water seepage real-time monitoring component. Specifically, the pigtails of the settlement deformation monitoring grating 3, the temperature compensation grating 6, and the water seepage deformation grating 11 are respectively connected to the grating demodulator 16 through the jumper 18 to realize the real-time transmission of the optical signals detected by the three gratings to the grating demodulator 16. The grating demodulator 16 is used to analyze the optical signals transmitted by the jumper 18 in order to generate the required data, and analyze the variables measured by the corresponding grating by observing the wavelength change of the fiber grating. The grating demodulator 16 is connected to the control end 17, and the data analyzed by the grating demodulator 16 is transmitted to the control end 17. The control end 17 performs relevant data compensation work, that is, the temperature data collected by the temperature compensation grating 6 is used to perform temperature compensation on the settlement deformation monitoring grating 3 and the water seepage deformation grating 11, so as to obtain more accurate settlement deformation data and the amount of water seepage. For the convenience of control, the grating demodulator 16 and the control end 17 are arranged on the ground.

[0045] As Figure 3 shown, the grating-based foundation settlement, temperature and water seepage monitoring device is arranged in the foundation under the high-temperature molten salt storage tank, and there are multiple monitoring units. Each monitoring unit includes a settlement and temperature real-time monitoring component and a water seepage real-time monitoring component. Each monitoring unit is on the same horizontal plane and is arranged in a linear array; each monitoring unit is connected to the grating demodulator 16 through the jumper 18. By analyzing the settlement deformation data generated at different positions in the same linear direction, the settlement situation of the foundation in this linear direction can be accurately analyzed. In this embodiment, the monitoring units are arranged in a circular array, that is, evenly divided into multiple groups in the circumferential direction, and multiple are evenly arranged in the radial direction in each group.

[0046] According to the above grating-based foundation settlement, temperature and water seepage monitoring device, the embodiment of the present invention also proposes a grating-based foundation settlement, temperature and water seepage monitoring method, including the following steps:

[0047] S1: According to the requirements of the above-mentioned grating-based ground settlement, temperature and seepage monitoring device, prefabricate the real-time settlement and temperature monitoring components and the real-time seepage monitoring components, and install the temperature compensation grating 6, the settlement deformation monitoring grating 3 and the seepage deformation grating 11 in the heat conduction protection shell 1 filled with heat conduction oil 2 according to the corresponding positions and connection requirements.

[0048] S2: Fill the device into the ground. During the compaction process of the ceramsite soil, lay the heat conduction protection shell 1 equipped with the three monitoring gratings in the ceramsite soil, and connect the three monitoring gratings to the grating demodulator 16 with jumpers 18 respectively.

[0049] S3: The grating demodulator 16 analyzes the optical signals returned by the three monitoring gratings. The principle is as follows:

[0050] When the grating is only affected by temperature, the change in the central wavelength drift of the grating is mainly reflected in two aspects: the thermo-optic effect causes the refractive index to change, and the thermal expansion effect causes the grating period to change. In this case, the optical signal returned by the temperature compensation grating 6 can be analyzed to obtain the central wavelength drift Δλ of the grating BT , and its expression is as follows:

[0051] Δλ BT =λ BT (ζ + α)·ΔT

[0052] In the formula, λ BT is the Bragg wavelength of the temperature compensation grating 6, α is the thermal expansion coefficient of the optical fiber, ζ is the thermo-optic coefficient of the optical fiber, and ΔT is the temperature change.

[0053] When the grating is only affected by settlement deformation, the change in the central wavelength drift of the grating is mainly reflected in two aspects: the elasto-optic effect causes the refractive index to change, and the settlement deformation causes the grating period to change. At this time, the expression of the central wavelength drift Δλ of the grating BS is as follows:

[0054] Δλ BS =λ BS (1 - P)ε

[0055] In the formula, λ BS is the Bragg wavelength when the settlement deformation monitoring grating 3 is only affected by settlement deformation, which is an unknown quantity; P is the elasto-optic coefficient of the optical fiber, and ε is the change in the grating period caused by the deformation of the optical fiber.

[0056] In practical applications, the settlement deformation monitoring grating 3 is affected by both settlement deformation and temperature at the same time, and temperature compensation needs to be carried out through the control end 17 to obtain Δλ BS .

[0057] When the grating is only affected by the swelling deformation due to water seepage, the change in the drift of the central wavelength of the grating is mainly reflected in two aspects: the elasto-optic effect changes the refractive index, and the swelling deformation due to water seepage changes the grating period. At this time, the drift of the central wavelength of the grating Δλ BW has the following expression:

[0058] Δλ BW = λ BW (1 - P)ε

[0059] where λ BW is the Bragg wavelength when the water-seepage deformation grating 11 is only affected by the swelling deformation due to water seepage, which is an unknown quantity.

[0060] In practical applications, the water-seepage deformation grating 11 is affected by both the swelling deformation due to water seepage and temperature. Temperature compensation needs to be carried out through the control end 17 to obtain Δλ BW .

[0061] S4: The grating demodulator 16 transmits the analyzed data to the control end 17, and the control end 17 performs temperature compensation. The specific operations are as follows:

[0062] The settlement deformation monitoring grating 3 is affected by both settlement deformation and temperature. Then, the drift of the central wavelength of the settlement deformation monitoring grating 3 has the following expression:

[0063]

[0064] where represents the Bragg wavelength when the settlement deformation monitoring grating 3 is actually detected.

[0065] The water-seepage deformation grating 11 is affected by both the swelling deformation due to water seepage and temperature. Then, the drift of the central wavelength of the water-seepage deformation grating 11 has the following expression:

[0066]

[0067] where represents the Bragg wavelength when the water-seepage deformation grating 11 is actually detected.

[0068] The control end 17 performs temperature compensation on the detection result of the settlement deformation monitoring grating 3, subtracts by Δλ BT , to obtain the drift of the central wavelength of the grating Δλ BS that is only affected by the settlement deformation, and then calculates the corresponding settlement deformation after temperature compensation. Based on the settlement deformations obtained from multiple monitoring units arranged in an array, it is judged whether there is local settlement of the foundation. Similarly, for the detection result of the water-seepage deformation grating 11, temperature compensation is performed, and is subtracted by ΔλBT , the drift amount Δλ of the grating center wavelength affected only by the swelling deformation due to seepage water is obtained BW , and then the swelling deformation amount due to seepage water after temperature compensation is calculated, so as to reflect the seepage situation.

[0069] The present invention is applicable to the real-time monitoring of multiple parameters such as temperature, settlement, and ceramsite soil seepage of various storage tank foundations or other suitable building foundations, and has a fast response speed and high monitoring accuracy, providing reference information for the operation state monitoring of high-temperature molten salt storage tanks.

[0070] Those of ordinary skill in the art can understand that the above are only preferred examples of the invention and are not used to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing examples, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, etc. made within the spirit and principle of the invention shall be included within the protection scope of the invention.

Claims

1. A grating-based ground settlement, temperature and seepage monitoring device, characterized in that, Including: Real-time settlement and temperature monitoring component, real-time seepage monitoring component, grating demodulator, control terminal, jumper wire; The real-time settlement and temperature monitoring component includes: a heat conduction protection shell, heat conduction oil, a plurality of settlement deformation monitoring gratings and grating protection layers, a plurality of temperature compensation gratings and lightweight plastic hard shells, and a conduction optical fiber; the heat conduction protection shell is a hollow structure and has flexibility and heat conductivity; the interior of the heat conduction protection shell is divided into a large chamber and a small chamber, and a one-way low-pressure oil return port and a one-way high-pressure oil drain port are respectively arranged on the partition surface. The large chamber is filled with heat conduction oil and can enter the small chamber through the one-way high-pressure oil drain port, and the heat conduction oil in the small chamber can enter the large chamber through the one-way low-pressure oil return port; the outside of each settlement deformation monitoring grating is wrapped with a grating protection layer having flexibility and heat conductivity, and the grating protection layer is axially fixedly connected to the inner wall of the heat conduction protection shell; the outside of each temperature compensation grating is wrapped with a lightweight plastic hard shell having heat conductivity, and the lightweight plastic hard shell floats in the heat conduction oil and corresponds one-to-one with the grating protection layer in the vertical direction; adjacent settlement deformation monitoring gratings and adjacent temperature compensation gratings are connected by a conduction optical fiber and transmit optical signals; The real-time seepage monitoring component includes: a seepage deformation grating, a compressible and expandable push rod, an expansion structure, a water isolation plate, and a seepage-sensitizing rubber funnel; the seepage deformation grating is arranged in the large chamber and is fixedly connected to the partition surface between the large chamber and the small chamber; the seepage-sensitizing rubber funnel is arranged outside the heat conduction protection shell and has openings and through-holes in both the upper and lower directions; a communication channel is horizontally arranged between the central position of the seepage deformation grating and the central position of the seepage-sensitizing rubber funnel, and an expansion structure that can expand when encountering water is arranged in the communication channel; a water isolation plate is horizontally arranged on the side of the expansion structure close to the seepage-sensitizing rubber funnel to isolate the upper and lower openings, and the side close to the heat conduction protection shell is in contact with one end of the compressible expansion rod push rod. In the initial installation state, the other end of the compressible expansion rod push rod is in contact with the seepage deformation grating and does not generate mutual force; The settlement deformation monitoring gratings and temperature compensation gratings of the real-time settlement and temperature monitoring component and the seepage deformation grating of the real-time seepage monitoring component are respectively connected to the grating demodulator through jumper wires, and the grating demodulator is connected to the control terminal. The control terminal is used to perform temperature compensation on the data analyzed by the grating demodulator to obtain the settlement deformation data and seepage volume after temperature compensation.

2. The grating-based ground settlement, temperature and seepage monitoring device according to claim 1, characterized in that, A plurality of the grating protection layers are sequentially and uniformly fixedly connected to the inner wall of the heat conduction protection shell along the axis by epoxy resin.

3. The grating-based ground settlement, temperature and seepage monitoring device according to claim 1, characterized in that, The interior of the lightweight plastic hard shell is hollow, and the temperature compensation grating is fixedly connected to the bottom of the lightweight plastic hard shell; after installing the temperature compensation grating, the gravity of the lightweight plastic shell is balanced with the buoyancy provided by the heat conduction oil.

4. The grating-based ground settlement, temperature and seepage monitoring device according to claim 1, wherein, The length of the conduction optical fiber is set with a redundancy amount to ensure that the temperature compensation grating is only affected by temperature.

5. The grating-based ground settlement, temperature and seepage monitoring device according to claim 1, characterized in that, The seepage-sensitizing rubber funnel is made of rubber material.

6. The grating-based ground settlement, temperature and seepage monitoring device according to claim 1, characterized in that, The device is arranged in the foundation and includes multiple monitoring units. Each monitoring unit includes a real-time settlement and temperature monitoring component and a real-time seepage monitoring component; the multiple monitoring units are on the same horizontal plane and are arranged in an array; each monitoring unit is connected to a grating demodulator through a jumper wire, and the settlement deformation data generated at different positions in the same linear direction is analyzed to analyze the settlement condition of the foundation in this linear direction.

7. The grating-based ground settlement, temperature and seepage monitoring device according to claim 6, characterized in that, The multiple monitoring units are arranged in a circumferential array, that is, they are evenly divided into multiple groups in the circumferential direction, and multiple are evenly arranged in each group along the radial direction.

8. A grating-based ground settlement, temperature and seepage monitoring method, implemented according to the grating-based ground settlement, temperature and seepage monitoring device described in any one of claims 1-7, characterized in that, It includes the following steps: S1: According to the requirements of the grating-based foundation settlement, temperature and seepage monitoring device, prepare the real-time settlement and temperature monitoring component and the real-time seepage monitoring component. The temperature compensation grating, settlement deformation monitoring grating and seepage deformation grating are installed in a heat-conducting protective shell filled with heat-conducting oil according to the corresponding positions and connection requirements. S2: Arrange the real-time settlement and temperature monitoring component and the real-time seepage monitoring component into the foundation, use jumper wires to connect the temperature compensation grating, settlement deformation monitoring grating and seepage deformation grating to the grating demodulator respectively, and connect the grating demodulator to the control end; the grating demodulator and the control end are placed on the upper surface of the foundation. S3: The grating demodulator analyzes the optical signals returned by the temperature compensation grating, settlement deformation monitoring grating and seepage deformation grating to obtain the central wavelength drift of each grating. S4: The grating demodulator transmits the analyzed data to the control end, and the control end performs temperature compensation: subtract the central wavelength drift of the temperature compensation grating from the central wavelength drift of the settlement deformation monitoring grating to obtain the temperature-compensated settlement deformation, so as to analyze whether there is local settlement in the foundation; subtract the central wavelength drift of the temperature compensation grating from the central wavelength drift of the seepage deformation grating to obtain the temperature-compensated seepage expansion deformation amount, so as to reflect the seepage situation.

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