CN108196036A - One-dimensional island underground water desalination simulation test device and its method - Google Patents

Abstract

The invention discloses a one-dimensional island groundwater desalination simulation test device and a method thereof, and relates to marine rock and soil model test technology. The device includes a test soil sample (00); is provided with a rainfall unit (10), a test unit (20), a fixed unit (30) and a receiving unit (40); the test soil sample (00) is placed in the test unit (20) ; The testing unit (20) is snapped into the fixing unit (30); from top to bottom, the rainfall unit (10), the testing unit (20) and the receiving unit (40) are sequentially connected. This device can analyze the desalination phenomenon under various geological conditions and rainfall conditions; the soil sensor can measure the changes of various parameters in real time, and at the same time it is convenient for sampling, microscopic analysis and water quality analysis; each part of the whole device can be disassembled, assembled and replaced independently. Simple, easy to operate, high precision.

Description

One-dimensional island groundwater desalination simulation test device and method

technical field

The invention relates to marine rock-soil model test technology, in particular to a one-dimensional island groundwater desalination simulation test device and method thereof.

technical background

In recent years, my country has vigorously carried out engineering construction in the South China Sea, creatively obtained local materials, and blown and filled the calcareous sediments in adjacent lagoons and waterways to the reefs to form artificial gray sand islands by means of suction and raking. At the same time, people have found in the long-term use of underground freshwater in islands that there is a desalinated water area that exists in a certain depth range under the ground of islands and reefs, floats on the salty seawater, and has a medium thickness and thin edges, that is, a "freshwater lens". . This desalinated water body suspended by rainfall infiltration and density difference is an extremely precious source of life supporting the animal and plant ecosystems of the islands and reefs in the South China Sea, and it is also a key factor affecting the ecological process of islands and reefs.

However, most of the existing island groundwater desalination simulations are strip-shaped, it is difficult to take undisturbed soil samples, and there are relatively few studies on the entire desalination mechanism. The mechanism of desalination is very important to the understanding of the formation of underground freshwater in the whole island. This process is gradual, long and has obvious time effects. Therefore, it is necessary to establish a set of equipment dedicated to the study of desalination mechanism, and to be able to obtain undisturbed soil for microscopic analysis.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and provide a one-dimensional sea island groundwater desalination simulation test device and method thereof.

The purpose of the present invention is achieved like this:

The main body of the device adopts a cylindrical model, equipped with multiple soil sensors to monitor the values of soil conductivity, temperature and volumetric moisture content in real time at different depths; after the experiment, undisturbed soil samples of the same depth can be taken out for CT scanning and soil main Determination of ions and pH values; while leaching, real-time changes in soil conductivity and leached water quality are obtained, revealing the desalination of soil columns under different experimental conditions, and combining microscopic analysis of its characteristics.

Specifically:

The device includes test soil samples;

It is equipped with a rainfall unit, a test unit, a fixing unit and a receiving unit;

Its location and connection relationship are:

The test soil sample is placed in the test unit;

The test unit snaps into the fixed unit;

From top to bottom, the rainfall unit, test unit and receiving unit are connected in sequence.

The present invention has following advantage and positive effect:

①The entire device is made of plexiglass, which can observe the entire infiltration process of water with the naked eye. At the same time, the inner cylinder can be raised after the experiment is over, which is more convenient to obtain undisturbed soil samples of the same depth, and the inner cylinder can be scanned by CT to analyze the structure The influence of relationships on dilution;

② There are round holes of the same diameter on the outer cylinder, which are arranged along a certain depth, which is very convenient for embedding and taking out the soil sensor;

③The rain unit can place needles of different sizes into the board, which can achieve uniform precipitation and simulate different rain intensities, which can better simulate real rainfall conditions;

④ The liquid storage tank can also be used as a device for simulating underground seawater, simulating the desalination situation when underground seawater exists. That is to say, this device can simulate various geological conditions and more truly reflect the desalination mechanism of islands and reefs.

In short, this device can analyze the desalination phenomenon under various geological conditions and rainfall conditions; the soil sensor can measure the changes of various parameters in real time, and at the same time facilitate sampling, microscopic analysis and water quality analysis; each part of the whole device can be disassembled, assembled and replaced independently , simple structure, convenient operation and high precision.

Description of drawings

Fig. 1 is the structural block diagram of this device;

Fig. 2 is the structural representation of this device;

Fig. 3-1 is the front view of rainfall unit 10,

Fig. 3-2 is the left side view of rainfall unit 10,

3-3 is a top view of the rainfall unit 10;

Fig. 4-1 is the front view of test unit 20,

Fig. 4-2 is the top view of testing unit 20;

Fig. 5-1 is the front view of fixing unit 30,

Fig. 5-2 is the left side view of fixing unit 30;

FIG. 5-3 is a top view of the fixing unit 30;

Fig. 6-1 is the front view of receiving unit 40,

Figure 6-2 is a left side view of the receiving unit 40,

FIG. 6-3 is a top view of the receiving unit 40 .

In the picture:

00—test soil sample;

10—rainfall unit,

11—water storage tank, 12—water quality measurement box, 13-1, 13-2—the first and second water pipes,

14—peristaltic pump, 15—precipitation tank, 16—needle insertion plate;

20 — test unit,

21—inner cylinder, 22—outer cylinder, 22-1—groove;

30—fixed unit,

31—disc base, 32—ring buckle, 33—back column;

40—receiving unit,

41—liquid storage tank, 44-1—the first seawater outlet hole, 41-2—the second seawater outlet hole,

41-3—Sea water inlet hole;

42—block, 42-1—large leakage hole.

Detailed ways

Below in conjunction with accompanying drawing and embodiment describe in detail:

1. Device

1. Overall

As shown in Figures 1 and 2, the device includes test soil sample 00;

A rainfall unit 10, a test unit 20, a fixing unit 30 and a receiving unit 40 are provided;

Its location and connection relationship are:

The test soil sample 00 is placed in the test unit 20;

The test unit 20 snaps into the fixing unit 30;

From top to bottom, the raining unit 10, the testing unit 20 and the receiving unit 40 are connected in sequence.

2. Functional unit

0) Test soil sample 00

Test soil sample 00 is the test object of this device.

1) Rainfall unit 10

As shown in Figures 3-1, 3-2, and 3-3, the rainfall unit 10 includes a water storage tank 11, a water quality measurement tank 12, a first water pipe 13-1, a peristaltic pump 14, a second water pipe 13-2, and a precipitation tank connected in sequence. 15 and needle insert plate 16.

Its main function is to simulate rainfall, and to study the influence of different rainfall conditions on the salt removal process by setting different rainfall intensities, rainfall amounts, and rainfall durations.

(1) Water storage tank 11

The water storage tank 11 is a cubic box of length×width×height=100cm×100cm×200cm, made of plexiglass, a water quality measurement box 12 is connected to the right side of the water storage tank 11, and the two boxes are connected to each other through holes. The water in the water storage tank 11 can freely enter the water quality measurement tank 12 .

(2) Water quality measurement box 12

The water quality measurement box 12 is a cube box of length * width * height = 50cm * 50cm * 100cm, made of plexiglass, just can be put into the water quality measuring instrument in it, and carries out the real-time water quality detection of entering water.

(3) The first and second water pipes 13-1 and 13-2

The first and second water pipes 13-1 and 13-2 are ordinary silicone pipes sold on the market, with a specification of 2mm×4mm.

(4) Peristaltic pump 14

The peristaltic pump 14 is a peristaltic pump used in conventional laboratories, which can adjust the flow rate and provide steady water supply for a long time.

(5) Precipitation tank 15

The precipitation box 15 is a cylinder with a cover, made of plexiglass, with an inner diameter of 20cm and a height of 5cm.

(6) Needle insert plate 16

The needle insertion plate 16 is a circular plate with holes adapted to the bottom surface of the precipitation box 15 .

The size of the hole has different specifications, which can simulate different rainfall intensities.

2) Test unit 20

As shown in Figures 4-1 and 4-2, the test unit 20 is composed of an inner cylinder 21 and an outer cylinder 22;

The centerlines of the inner cylinder 21 and the outer cylinder 22 coincide, and the space between the inner cylinder 21 and the outer cylinder 22 and the inner cylinder 21 are filled with the test soil sample 00.

The function of the test unit 20: it is the main container for loading the test soil sample 00, and can extract undisturbed soil samples of the same depth for microscopic analysis after the experiment is over.

(1) inner cylinder 21

The inner cylinder 21 is a long plexiglass cylinder with a diameter of 2 cm and a height of 100 cm. The cylinder wall is provided with a small hole 21-1; the inner cylinder 21 communicates with the outer cylinder 22 through the small hole 21-1;

The diameter of the inner cylinder 21 is 2 cm, which is more suitable for CT scanning, and its setting is to obtain the undisturbed test soil sample 00 of the same depth after the experiment more conveniently.

(2) Outer cylinder 22

Outer cylinder 22 is a kind of plexiglass long cylinder, diameter 20cm, height 100cm, two grooves 22-1 up and down are arranged outside cylinder wall; There are 2 grooves 22-1 in outer cylinder outside, convenient ring buckle 32 fixes outer Barrel 22.

3) Fixed unit 30

As shown in Figures 5-1, 5-2, and 5-3, the fixing unit 30 is composed of a disc base 31, a buckle 32 and a back post 33;

The disk base 31 and the back column 33 are vertically connected to form an L-shaped whole, and the upper and lower parts of the back column 33 are respectively provided with buckles 32 .

The function of the fixing unit 30 is to prevent the testing unit 20 from moving during the experiment and affect the experiment result.

(1) Disc base 31

The disc base 31 is a metal ring;

(2) Buckle 32

The ring buckle 32 is a 2/3 circular elastic metal piece that fits with the groove 22-1 of the outer cylinder 22;

(3) Back column 33

The back column 33 is a long column with a square cross section.

4) Receiving unit 40

As shown in Figures 6-1, 6-2, and 6-3, the receiving unit 40 includes a liquid storage tank 41 and a spacer 42 , and the spacer 42 covers the liquid storage tank 41 .

The function of the receiving unit 40 is: on the one hand, it is used as a storage container to receive the liquid from the upper test soil sample 00, and during the experiment, it is convenient to extract water samples for water quality testing; on the other hand, it is used as a device for simulating the existence of underground seawater .

(1) Liquid storage tank 41

The liquid storage barrel 41 is a kind of drum with a diameter of 32cm and a height of 15cm. The back of the liquid barrel 41 is provided with a second seawater outlet hole 41-2;

Different from the water storage tank 11, the liquid storage barrel 41 is to receive the water sample after the upper test soil sample 00 is rinsed, so as to facilitate the measurement and analysis of the desalination situation in different time periods; the upper part of the liquid storage barrel 41 is connected with the outer cylinder 22 and the The inner cylinder 21 is connected.

(2) Block 42

The spacer 42 is a round block with a diameter of 32 cm and a height of 2 cm, made of plexiglass, and a large leak hole 42-1 is arranged on it, through which the liquid of the test soil sample 00 flows into In the liquid storage tank 41.

Its working mechanism:

The liquid storage tank 41 takes a sample through the sea water inlet hole 41-3, so that the water sample in the device will not be disturbed;

Liquid storage barrel 41 can carry out the function of sampling and liquid storage on the one hand, and simultaneously he can also be used as the situation when simulating underground seawater; Enter from the seawater inlet hole 41-3, wait until it rises to a certain height, and open the first seawater outlet hole 41-1 and the second seawater outlet hole 41-2 at the same time; the lower part continues to flow into the seawater, and the excess seawater comes out from the upper two The hole flows out to reach a constant water head situation; at this time, the cushion block 42 is removed, and the test unit 20 is directly put into the liquid storage barrel 41 for experimentation.

3. The working principle of this device:

The test soil sample 00 is compacted in layers in the inner cylinder 21 and the outer cylinder 22, and then the device is fixed on the fixing unit 30; the upper rainfall unit 10 simulates rainfall, and changes the rainfall intensity according to the experimental conditions; from the outer cylinder 22 Insert the soil sensor to monitor the conductivity, temperature and volumetric moisture content of the test soil sample 00 in real time; during the experiment, obtain the water sample after rinsing from the liquid storage tank 41, and analyze its pH and chloride ion concentration; The test soil sample 00 of the outer cylinder 22 was excavated to obtain the CT scan and ion analysis of the undisturbed test soil sample 00 of the inner cylinder 21 .

At the same time, in order to better reflect the actual situation of the island, the existence of underground seawater can be established according to the experimental requirements to study the influence of underground seawater on desalination.

2. Simulation test method

This method comprises the following steps:

① Put the water storage bucket 41 into the fixed base 31, install the spacer 42, and place the inner cylinder 21 and the outer cylinder 22 on the spacer 42 at the same time. Buckle 32 is fixed;

② The test soil sample 00 is compacted in layers, and put between the inner cylinder 21 and the outer cylinder 22, as well as in the inner cylinder 21. At the same time, insert the soil sensor into the outer cylinder 22 to monitor the conductivity, temperature and temperature of the test soil sample 00 in real time. Changes in volumetric moisture content;

③Install the rainfall unit 10 on the upper part of the device, put the needle insertion plate 16 into the bottom of the precipitation box 16, and select different sizes of apertures according to the needs of the experiment; the precipitation box 11 is fixed on the needle insertion plate 16, connected by the second water pipe 13-2 To the peristaltic pump 14; the peristaltic pump 14 is connected to the water quality measurement box 12 through the first water pipe 13-1, and pumps water from the water quality measurement box 12 to the precipitation tank 15;

④ After the device is installed, simulate rainfall, collect data from the soil sensor at regular intervals, and open the seawater inlet hole 41-3 to extract water samples and analyze the water quality of the effluent;

⑤ If it is necessary to change the simulated geological conditions and increase the presence of underground seawater; use the seawater inlet hole 41-3 in the liquid storage tank 41 as the seawater inlet, the first seawater outlet hole 44-1 and the second water outlet hole 41-2 serves as redundant seawater outflow outlet, simulating the impact on desalination of islands and reefs when underground seawater exists;

6. After the experiment is over, dig out the test soil sample 00 between the outer cylinder 22 and the inner cylinder 21, extract the inner cylinder 22 and carry out CT scanning; at the same time, take samples to analyze the main ions and pH value of the test soil sample 00;

⑦The device is dismantled, removed in turn from top to bottom, and cleaned.

Claims (6)

1. A one-dimensional island groundwater desalination simulation test device, including test soil samples (00); It is characterized by: A rainfall unit (10), a test unit (20), a fixing unit (30) and a receiving unit (40) are provided; Its location and connection relationship are: The test soil sample (00) is placed in the test unit (20); The test unit (20) snaps into the fixing unit (30); From top to bottom, the raining unit (10), the testing unit (20) and the receiving unit (40) are connected in sequence. 2. The one-dimensional sea island groundwater desalination simulation test device according to claim 1, characterized in that: The rainfall unit (10) includes a water storage tank (11), a water quality measurement tank (12), a first water pipe (13-1), a peristaltic pump (14), a second water pipe (13-2), and precipitation box (15) and needle insert plate (16). 3. The one-dimensional sea island groundwater desalination simulation test device according to claim 1, characterized in that: The test unit (20) is composed of an inner cylinder (21) and an outer cylinder (22); The center lines of the inner cylinder (21) and the outer cylinder (22) coincide, and the test soil sample (00) is filled between the inner cylinder (21) and the outer cylinder (22) and in the inner cylinder (21); The inner cylinder (21) is a long plexiglass cylinder with a diameter of 2cm and a height of 100cm. The cylinder wall is provided with a small hole (21-1); the inner cylinder (21) passes through the small hole (21-1) and the outer cylinder (22) Connected; The outer cylinder (22) is a long plexiglass cylinder with a diameter of 20cm and a height of 100cm. Two grooves (22-1) are arranged outside the cylinder wall. 4. The one-dimensional sea island groundwater desalination simulation test device according to claim 1, characterized in that: The fixing unit (30) is composed of a disc base (31), a buckle (32) and a back column (33); The disc base (31) and the back column (33) are vertically connected to form an L-shaped whole, and ring buckles (32) are arranged on the upper and lower parts of the back column (33); Disc base (31) is a kind of metal ring; The ring buckle (32) is a 2/3 circular elastic metal sheet adapted to the groove (22-1) of the outer cylinder (22); The back column (33) is a long column with a square cross section. 5. The one-dimensional sea island groundwater desalination simulation test device according to claim 1, characterized in that: The receiving unit (40) includes a liquid storage barrel (41) and a spacer (42), and the spacer (42) is covered on the liquid storage barrel (41); The liquid storage barrel (41) is a kind of drum, and the left side of the liquid storage barrel (41) is provided with the first sea water outlet hole (41-1) and the sea water inlet hole (41-3). ) is provided with a second seawater outlet hole (41-2); Pad block (42) is a kind of round block, is provided with large leakage hole (42-1) on it. 6. based on the simulation test method of the one-dimensional sea island groundwater desalination simulation test device of claim 1-5, it is characterized in that: ① Put the water storage bucket (41) into the fixed base (31), install the spacer (42), and put the inner cylinder (21) and outer cylinder (22) on the spacer (42) at the same time, the inner cylinder (21) coincides with the center line of the outer cylinder (22), and is fixed by the ring buckle (32); ②The test soil sample (00) is compacted in layers, put it between the inner cylinder (21) and the outer cylinder (22), and into the inner cylinder (21), and at the same time insert the soil sensor into the outer cylinder (22) for real-time monitoring Changes in conductivity, temperature and volumetric moisture content of the test soil sample (00); ③Install the rainfall unit (10) on the upper part of the device, put the needle insertion plate (16) into the bottom of the precipitation box (16), and select different sizes of apertures according to the experimental needs; the precipitation box (11) is fixed on the needle insertion plate (16) above, connect to the peristaltic pump (14) through the second water pipe (13-2); the peristaltic pump (14) connects to the water quality measurement box (12) through the first water pipe (13-1), and draws water from the water quality measurement box (12) to precipitation box(15); ④ After the device is installed, simulate rainfall, collect data from the soil sensor at regular intervals, and open the seawater inlet (41-3) to extract water samples and analyze the quality of the effluent; ⑤ If it is necessary to change the simulated geological conditions, increase the presence of underground seawater; use the seawater inlet hole (41-3) in the liquid storage tank (41) as the seawater inlet, the first seawater outlet hole (44-1) and The No. 2 water outlet hole (41-2) is used as a redundant seawater outflow outlet to simulate the impact on desalination of islands and reefs when underground seawater exists; ⑥ At the end of the experiment, dig out the test soil sample (00) between the outer cylinder (22) and the inner cylinder (21), extract the inner cylinder (22) for CT scanning; at the same time, take samples for the test soil sample (00) main ions and pH value analysis; ⑦The device is dismantled, removed in turn from top to bottom, and cleaned.