Moisture and salinity migration measuring device under temperature control

Abstract

The utility model discloses a moisture and salt migration measuring device under temperature control, which can simulate the moisture and salt diffusion phenomenon under the action of temperature gradient by applying temperature to the closed end of a soil column and keeping constant environment temperature at the open end of the soil column. Strict heat insulation and sealing measures are set, so that the loss of heat and moisture in the temperature applying process is reduced as much as possible, the migration amount of moisture and salt can be monitored in real time by integrating a high-precision balance and a sensor, the measurement accuracy and the experiment repeatability are improved, and the temperature gradient is applied through a heating plate and a temperature controller, so that the measurement accuracy is improved. By adopting the design of the heat insulation lining and the heating plate, the problem of heat loss in water bath heating is avoided, the uniformity and stability of the temperature are ensured, so that the accuracy of an experimental result is improved, and the moisture and salinity migration measuring device under temperature control is compact in structure, simple and convenient to operate, capable of adapting to different experimental conditions and requirements and high in practicability. And the experiment flexibility is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of geotechnical engineering tests, in particular to a device for measuring the migration of water and salt under temperature control. Background Art

[0002] In the field of soil science and environmental engineering, the study of the migration law of water and salt in soil is of great significance. At present, the existing experimental instruments are mainly focused on the study of liquid water migration in soil under the action of temperature gradient. At the same time, some scholars have also measured and calculated the migration of gaseous water under the influence of temperature gradient. However, most of these studies focus on the heat-water-vapor coupling process, while there are relatively few studies on the water-heat-salt coupling process. In terms of salt measurement, traditional methods such as slicing method require longer specimens and longer test time, which to a certain extent limits the efficiency and application scope of the experiment. In addition, common heating methods such as water bath heating have some inconveniences in actual operation, such as easy evaporation of water and easy loss of heat, and may affect the measurement results of salt migration.

[0003] In view of this, a device for measuring the migration of water and salt under temperature control is designed. Utility Model Content

[0004] The purpose of the utility model is to provide a device for measuring the migration of water and salt under temperature control, so as to solve the problems existing in the prior art mentioned in the above background technology.

[0005] To achieve the above object, the utility model provides the following technical solutions: a device for measuring the migration of water and salt under temperature control, comprising a constant temperature box, an upper clamping plate, a lower clamping plate and a matching mold;

[0006] A high-precision balance is fixedly provided on the inner bottom of the constant temperature box;

[0007] The upper and lower clamps are arranged on the inner side of the thermostatic box, and the upper and lower clamps are spliced ​​up and down, and a plurality of groups of hoops are arranged at equal intervals on the outer sides of the upper and lower clamps, and a left clamp and a right clamp are respectively arranged on both sides of the upper and lower clamps by bolts, a level is installed on the top of the upper clamp, and a heat-insulating outer layer, a fixed outer lining and a heat-insulating inner lining are arranged on the inner sides of the upper and lower clamps, and the heat-insulating outer layer, the fixed outer lining and the heat-insulating inner lining are sequentially arranged from the outside to the inside;

[0008] The inner side of the thermal insulation lining is provided with thermal insulation cotton, thermal insulation board, heating board and salt solution cabin, and the thermal insulation cotton, thermal insulation board, heating board and salt solution cabin are sequentially arranged from the left clamping plate to the right clamping plate, and a salt solution cabin and a thermal insulation cotton are provided on the inner side of the thermal insulation lining near the right clamping plate;

[0009] The thermal insulation outer layer, the fixed outer lining and the thermal insulation inner lining are interspersed with moisture sensors and salt sensors;

[0010] A first injection pipe is inserted and connected in the top of the thermostatic box and the upper clamping plate, and the first injection pipe passes through the thermal insulation outer layer, the fixed outer lining, and the thermal insulation inner lining to be connected to one group of salt solution tanks, and a second injection pipe is inserted and connected in the right clamping plate, and the second injection pipe passes through the thermal insulation cotton to be connected to another group of salt solution tanks;

[0011] The outer diameter length of the matching mold is matched with the inner diameter length of the thermal insulation lining, and the matching mold is suitable for compacting soil samples.

[0012] Preferably, a first annular groove is formed on one side of the left clamping plate close to the thermal insulation lining, and a first sealing ring is embedded in the first annular groove.

[0013] Preferably, second annular grooves are provided in the inner wall of the thermal insulation lining and the surface of the heating plate, and second sealing rings are connected to two groups of the second annular grooves.

[0014] Preferably, the outer diameter length of the salt solution tank is matched with the inner diameter length of the thermal insulation lining, and a plurality of groups of through holes are opened through the salt solution tank.

[0015] Preferably, the moisture sensors and salt sensors are each provided in a plurality of groups, and the plurality of groups of moisture sensors and the plurality of groups of salt sensors are spatially distributed in a spiral manner along the inner wall of the thermal insulation lining.

[0016] Compared with the prior art, the beneficial effects of the utility model are:

[0017] 1. The temperature-controlled moisture and salt migration measuring device can simulate the phenomenon of moisture and salt diffusion under the action of temperature gradient by applying temperature at the closed end of the soil column and maintaining a constant ambient temperature at the open end of the soil column. Strict insulation and sealing measures are set to minimize the loss of heat and moisture during the temperature application process.

[0018] 2. The temperature-controlled water and salt migration measuring device can monitor the migration of water and salt in real time by integrating high-precision balances and sensors, thus improving the accuracy of the measurement and the repeatability of the experiment;

[0019] 3. The temperature-controlled water and salt migration determination device applies a temperature gradient through a heating plate and a temperature controller. The design of a heat-insulating lining and a heating plate avoids the problem of heat loss in water bath heating, ensures uniform and stable temperature, and thus improves the accuracy of the experimental results.

[0020] 4. The temperature-controlled water and salt migration determination device has a compact structure, is easy to operate, can adapt to different experimental conditions and requirements, and improves the flexibility of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a front structural cross-sectional view of a device for measuring water and salt migration under temperature control according to the utility model;

[0022] Figure 2 This is a partial front structural cross-sectional view of a device for measuring water and salt migration under temperature control according to the utility model;

[0023] Figure 3 This is a front structural cross-sectional view of a matching mold of a device for measuring water and salt migration under temperature control of the utility model;

[0024] Figure 4 A cross-sectional view of a solid plastic pipe installed in a matching mold of a device and method for measuring water and salt migration under temperature control of the present invention;

[0025] Figure 5 The utility model is a side view of an upper clamping plate and a lower clamping plate of a device for measuring the migration of water and salt under temperature control.

[0026] In the figure:

[0027] 1. Constant temperature box; 2. High-precision balance; 3. Upper clamping plate; 4. Lower clamping plate;

[0028] 5. Hoop; 6. Left splint; 7. Right splint; 8. Insulation outer layer;

[0029] 9. Fixed outer lining; 10. Thermal insulation inner lining; 11. First annular groove; 12. First sealing ring;

[0030] 13. Insulation cotton; 14. Insulation board; 15. Heating board; 16. Moisture sensor;

[0031] 17. Salt sensor; 18. Level gauge; 19. Second sealing ring; 20. First injection pipe;

[0032] 21. Second injection pipe; 22. Salt solution tank; 23. Second annular groove; 24. Matching mold. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] In the description of the utility model, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0035] In the description of the utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0036] See also Figure 1-5 The utility model provides a technical solution: a device for measuring the migration of water and salt under temperature control, comprising a constant temperature box 1, an upper clamping plate 3, a lower clamping plate 4 and a matching mold 24.

[0037] Specifically, the constant temperature box 1 provides a stable temperature environment to ensure the consistency of experimental conditions.

[0038] A high-precision balance 2 is fixedly provided on the inner bottom of the constant temperature box 1 .

[0039] The upper splint 3 and the lower splint 4 are arranged on the inner side of the constant temperature box 1, and the upper splint 3 and the lower splint 4 are spliced ​​up and down, and a plurality of groups of hoops 5 are equidistantly arranged on the outer sides of the upper splint 3 and the lower splint 4, and the left splint 6 and the right splint 7 are respectively provided on both sides of the upper splint 3 and the lower splint 4 by bolts, and a spirit level 18 is installed on the top of the upper splint 3, and the inner sides of the upper splint 3 and the lower splint 4 are provided with an insulating outer layer 8, a fixed outer lining 9 and an insulating inner lining 10, and the insulating outer layer 8, the fixed outer lining 9 and the insulating inner lining 10 are sequentially fitted from the outside to the inside.

[0040] For details, please refer to the attached manual. Figure 5 The inner sides of the upper splint 3 and the lower splint 4 are both semi-cylindrical cavities. After the upper splint 3 and the lower splint 4 are assembled, the inner sides of the upper splint 3 and the lower splint 4 are combined into a cylindrical cavity.

[0041] The left clamping plate 6 is provided with a first annular groove 11 on one side close to the heat-insulating lining 10, and a first sealing ring 12 is embedded in the first annular groove 11. Specifically, the arrangement of the first annular groove 11 and the first sealing ring 12 effectively improves the sealing performance between the left clamping plate 6 and the heat-insulating lining 10, thereby improving the sealing performance of the device and preventing the leakage of water and salt during the experiment.

[0042] The inner side of the thermal insulation lining 10 is provided with thermal insulation cotton 13, thermal insulation board 14, heating board 15 and salt solution cabin 22. The thermal insulation cotton 13, thermal insulation board 14, heating board 15 and salt solution cabin 22 are sequentially arranged from the left clamping plate 6 toward the right clamping plate 7, and a salt solution cabin 22 and a thermal insulation cotton 13 are provided on the inner side of the thermal insulation lining 10 near the right clamping plate 7.

[0043] Specifically, the heating plate 15 also includes a temperature controller and a thermocouple. The heating plate 15 can be used to heat the soil and apply temperature more evenly. The temperature controller can control the temperature, thereby realizing water-salt migration tests under different diffusion speeds and temperature gradients.

[0044] The inner wall of the heat-insulating liner 10 and the surface of the heating plate 15 are both provided with second annular grooves 23, and the second sealing rings 19 are connected to the two sets of second annular grooves 23. Specifically, the second annular grooves 23 and the second sealing rings 19 are provided to further enhance the sealing performance of the device, thereby ensuring the uniformity and stability of the heating process.

[0045] A moisture sensor 16 and a salt sensor 17 are interspersed and installed in the thermal insulation outer layer 8 , the fixed outer lining 9 and the thermal insulation inner lining 10 .

[0046] There are several groups of moisture sensors 16 and salt sensors 17, which are spatially distributed in a spiral manner along the inner wall of the thermal insulation lining 10. Specifically, the probes of the several groups of moisture sensors 16 and the several groups of salt sensors 17 are arranged at different heights, and the spiral distribution of the several groups of moisture sensors 16 and the several groups of salt sensors 17 provides more comprehensive data collection, enhances the representativeness and reliability of the measurement results, and measures the water-salt distribution in the soil column through the moisture sensors 16 and the salt sensors 17, revealing the water-salt distribution in the soil column under the temperature gradient and the salt diffusion under the influence of temperature, thereby simulating the spatiotemporal distribution of water and salt under different salt concentrations, diffusion rates, and temperature gradients.

[0047] A first injection pipe 20 is inserted and connected in the top of the thermostatic box 1 and the upper splint 3. The first injection pipe 20 passes through the thermal insulation outer layer 8, the fixed outer lining 9, and the thermal insulation inner lining 10 to be connected to one group of salt solution tanks 22. A second injection pipe 21 is inserted and connected in the right splint 7. The second injection pipe 21 passes through the thermal insulation cotton 13 to be connected to another group of salt solution tanks 22.

[0048] Specifically, the first injection pipe 20 and the second injection pipe 21 are both used to input saline solution. The system unit is mainly applied at the left end. Two ports are set for salt application. According to actual conditions, the salt simulation direction can be selected. Water heads can be set on the first injection pipe 20 and the second injection pipe 21 to control the injection speed of the salt solution and the concentration change.

[0049] The outer diameter length of the salt solution tank 22 is matched with the inner diameter length of the thermal insulation liner 10, and a plurality of through holes are provided in the salt solution tank 22. Specifically, the size design of the salt solution tank 22 is matched with the thermal insulation liner 10, ensuring the uniform distribution and effective migration of the salt, and the provision of the through holes allows the water and salt to migrate freely in the salt solution tank, thereby improving the flexibility and accuracy of the measurement.

[0050] The outer diameter of the matching mold 24 is matched with the inner diameter of the heat-insulating liner 10, and the matching mold 24 is suitable for compacting the soil sample. Specifically, one side of the matching mold 24 is an opening structure for placing the soil sample to be tested, and the matching mold 24 is provided with a plurality of through holes, and the inner diameter of the through holes is matched with the inner diameter of the probe of the moisture sensor 16 and the inner diameter of the probe of the salt sensor 17.

[0051] Specifically, during use, in order to reduce the influence of gravity and focus on studying the water-salt migration phenomenon under the influence of heat, the soil column samples are placed horizontally.

[0052] Specifically, the device for measuring the migration of water and salt under temperature control can monitor the migration amount of water and salt in real time by integrating a high-precision balance 2 and a sensor, thereby improving the accuracy of the measurement and the repeatability of the experiment.

[0053] Specifically, when in use, first take the prepared wet soil, compact it in layers according to the target dry density into the matching mold 24, then take a number of solid plastic tubes and insert them into the soil sample through the holes on the matching mold 24, seal and let it stand for 24 hours to make the moisture in the soil column evenly distributed, then pull the solid plastic tubes out of the matching mold 24, take the well-maintained soil out of the matching mold, put it into the measuring device through the reserved opening on the side, so that the soil is placed on the inner side of the thermal insulation lining 10, align the holes in the soil with the sensor probe, and then put the thermal insulation outer layer 8 and the fixed outer layer 10 on the soil. Lining 9 and thermal insulation lining 10 are installed in place, and then the thermal insulation cotton, thermal insulation board 14, heating board 15, and salt solution cabin 22 are installed, and the upper clamping plate 3, lower clamping plate 4, left clamping plate 6, right clamping plate 7 and other components are installed and fixed. The soil column model is placed on the high-precision electronic balance 2 in the constant temperature box 1, and the relevant lines are connected. Pay attention to whether the moisture is lost. Set the heating plate temperature T1 (℃) on the data management and processing system, and set the constant temperature box temperature to T2 (℃). The temperature gradient of the test soil column is, where is the temperature gradient (℃ / cm), L is the length of the soil sample (cm), start the test, record and save the data. The salt content is measured by the conductivity salinity sensor and the salt concentration is directly output in the data system. When recording, each sensor saves and records the value in real time. For each point, a curve of the change of water content and salt over time is drawn. After the overall stability, you can choose to output the relationship between the water content of the test soil column and the position of the measuring point. After a set of tests, the soil column is divided into several samples, and each thin slice of the soil column is divided into two parts, one for measuring water content and the other for measuring salt concentration. Finally, each result is directly multiplied by 2 by default. When measuring water content, the drying method is used for determination. The salt concentration is in accordance with the provisions of US EPA1312 (USEPA, 1994). The soil sample is diluted with deionized water to make the solid-water ratio of 1:20. The sample is prepared for chemical analysis. The chemical concentration data is obtained by inductively coupled plasma mass spectrometry, and then the water extract concentration is converted into chemical concentration in the form of mol / kg. The final water content and salt concentration are plotted separately and merged into a distribution curve.

[0054] Specifically, an extractable solid plastic tube of the same thickness is provided at the reserved hole of the sensor. The diameter and length of the extractable solid plastic tube are compatible with the diameter and length of the moisture sensor probe and the diameter and length of the salt sensor probe. Reserved holes are set on the matching mold for the solid plastic tube to be inserted for subsequent soil sample compaction, and the solid plastic tube can be pulled out. Therefore, after the compacted soil sample is taken out, corresponding holes can remain on the soil sample for subsequent sensor probe insertion.

[0055] Specifically, according to actual use needs, a three-in-one soil moisture, temperature and salinity sensor can be selected, such as model TTMEC, which can provide real-time data on soil status. Several groups of sensors are arranged in a spiral shape to improve measurement accuracy, but due to different measurement positions, different data distribution maps may be obtained. This difference is helpful for understanding the spatial distribution of moisture and salt in the soil. Multiple measurements can be used to take the average value to reduce errors.

[0056] Specifically, the salt solution can be effectively diffused by using several groups of through holes on the surface of the salt solution tank 22, and gravity diffusion can be used, but this may cause the solution to have a higher concentration in a certain part of the soil. In order to achieve more uniform diffusion, a control device can be used to adjust the flow rate and distribution of the solution, such as installing a valve, water head, etc. on the injection pipe for control.

[0057] Specifically, if the distance between the heating plate 15 and the salt solution chamber 22 is too close, the diffusion effect may be affected, because heating may change the viscosity and diffusion coefficient of the solution. Insulating materials can be used to separate the heating plate 15 and the salt solution chamber 22 to reduce the effect of heat on the diffusion process. Materials with different insulating properties are selected according to actual use requirements.

[0058] Specifically, moisture and other factors have a certain influence on the salt measurement. Changes in soil moisture content will affect the reading of the salt sensor 17, because the interaction between moisture and salt in the soil will affect the conductivity measurement of the sensor. Therefore, it is necessary to control the moisture input as much as possible during measurement, and it is necessary to take an average value of multiple measurements to reduce errors.

[0059] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for measuring water and salt migration under temperature control, characterized in that: It comprises a constant temperature box (1), an upper clamping plate (3), a lower clamping plate (4) and a matching mold (24); A high-precision balance (2) is fixedly provided on the inner bottom of the constant temperature box (1); The upper clamping plate (3) and the lower clamping plate (4) are arranged on the inner side of the thermostatic box (1), and the upper clamping plate (3) and the lower clamping plate (4) are spliced ​​up and down, and a plurality of groups of hoops (5) are arranged at equal intervals on the outer sides of the upper clamping plate (3) and the lower clamping plate (4), and a left clamping plate (6) and a right clamping plate (7) are respectively arranged on both sides of the upper clamping plate (3) and the lower clamping plate (4) by bolts, and a level (18) is installed on the top of the upper clamping plate (3), and a heat-insulating outer layer (8), a fixed outer lining (9) and a heat-insulating inner lining (10) are arranged on the inner sides of the upper clamping plate (3) and the lower clamping plate (4), and the heat-insulating outer layer (8), the fixed outer lining (9) and the heat-insulating inner lining (10) are sequentially arranged from the outside to the inside; The inner side of the thermal insulation lining (10) is provided with thermal insulation cotton (13), a thermal insulation board (14), a heating board (15) and a salt solution cabin (22); the thermal insulation cotton (13), the thermal insulation board (14), the heating board (15) and the salt solution cabin (22) are arranged in sequence from the left clamping plate (6) to the right clamping plate (7); and a salt solution cabin (22) and a thermal insulation cotton (13) are provided on the inner side of the thermal insulation lining (10) near the right clamping plate (7); A moisture sensor (16) and a salt sensor (17) are installed in the thermal insulation outer layer (8), the fixed outer lining (9) and the thermal insulation inner lining (10); A first injection pipe (20) is inserted and connected in the top of the thermostatic box (1) and the upper clamping plate (3), and the first injection pipe (20) passes through the thermal insulation outer layer (8), the fixed outer lining (9), and the thermal insulation inner lining (10) to be connected to one group of salt solution tanks (22); a second injection pipe (21) is inserted and connected in the right clamping plate (7), and the second injection pipe (21) passes through the thermal insulation cotton (13) to be connected to another group of salt solution tanks (22); The outer diameter length of the matching mold (24) is matched to the inner diameter length of the thermal insulation lining (10), and the matching mold (24) is suitable for compacting soil samples.

2. The device for measuring water and salt migration under temperature control according to claim 1, characterized in that: A first annular groove (11) is provided on the side of the left clamping plate (6) close to the heat-insulating lining (10), and a first sealing ring (12) is embedded in the first annular groove (11).

3. The device for measuring water and salt migration under temperature control according to claim 1, characterized in that: Second annular grooves (23) are provided in the inner wall of the thermal insulation lining (10) and the surface of the heating plate (15), and second sealing rings (19) are connected to two groups of the second annular grooves (23).

4. The device for measuring water and salt migration under temperature control according to claim 1, characterized in that: The outer diameter length of the salt solution tank (22) is matched to the inner diameter length of the thermal insulation lining (10), and a plurality of groups of through holes are provided in the salt solution tank (22).

5. The device for measuring water and salt migration under temperature control according to claim 1, characterized in that: The moisture sensors (16) and the salt sensors (17) are each provided in a plurality of groups, and the plurality of groups of moisture sensors (16) and the plurality of groups of salt sensors (17) are spatially distributed in a spiral manner along the inner wall of the heat-insulating lining (10).

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