Underground water desalination model test system and method

Abstract

The invention discloses an underground water desalination model test system and method, and the system consists of an artificial rainfall system, an island form and stratum structure simulation system, and a test observation test system. A main body of the island form and stratum structure simulation system is divided into different areas through wall partition plates to simulate a seawater environment and island reef and stratum forms. In the test process, a calcium powder fine sand sample subjected to similar grading and scale reduction treatment is added into the island form and stratum structure simulation system to simulate an island reef, and self-made seawater is filled to simulate the marine environment. An artificial rainfall simulation system is used for simulating the natural rainfall process, water samples collected at different positions at different time are analyzed, and the gradual desalination process of underground water of the island reef under the artificial rainfall supply effect is reflected. The coral reef underground water desalination and conservation process under different rainfall intensities, different reef forms and different stratum structures can be simulated, and the coral reef underground water desalination and conservation device is visual, clear, easy and convenient to operate, easy to control and suitable for island reef underground water desalination and conservation mechanism research.

Description

Technical Field

[0001] The present invention relates to the field of marine geotechnical engineering and island and reef groundwater desalination technology, and more specifically to an island and reef groundwater desalination model test system and method that takes into account changes in island morphology and stratum structure. Background Art

[0002] According to the investigation and research of natural gray sand islands by many scholars, under the special geological, topographic and vegetation spatial pattern of coral islands and reefs and abundant rainfall supply, the groundwater of coral islands and reefs gradually desalinates under the action of rainfall infiltration, forming freshwater lenses that exist within the islands and reefs and are suspended above the seawater. This part of freshwater resources is crucial to the maintenance and protection of the island and reef ecosystem. With the proposal of my country's "ocean power" strategy, many scholars have begun to conduct extensive research on freshwater lenses, and have carried out a lot of research work based on the Ghyben-Herzberg model, Darcy's law, and the law of conservation of mass. The formation process of freshwater lenses has been simulated with the help of numerical simulation software such as Modflow. However, due to the lack of understanding of the actual island and reef strata and the formation process of freshwater lenses, the existing numerical simulation research mostly remains at the theoretical level, which is difficult to combine with the actual situation and still has certain limitations. Summary of the invention

[0003] In view of this, the present invention designs a model test system and method for groundwater desalination on islands and reefs that takes into account changes in island morphology and stratum structure. The system and method can economically and effectively carry out research on freshwater lenses, have strong operability, and can flexibly adjust the stratum structure and morphology of islands and reefs according to the purpose of the test. Through the visualized test process, researchers can more intuitively and deeply understand the influence mechanism of different stratum structures and rainfall infiltration on the formation of freshwater lenses.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] A groundwater desalination model test system, comprising: an artificial rainfall system, an island morphology and stratum structure simulation system and an experimental observation and testing system;

[0006] The artificial rainfall system simulates natural precipitation falling into the island morphology and stratum structure simulation system, and the experimental observation and testing system is connected to the island morphology and stratum structure simulation system.

[0007] Preferably, the artificial rainfall system comprises a water pump and a spray component connected in sequence through pipelines;

[0008] The water pump is placed in the water storage tank;

[0009] The spray component includes a spray pipe, a spray head is arranged on the spray pipe, and the spray head is located above the island morphology and stratum structure simulation system;

[0010] The spray pipe and the pipeline are both connected with an air pump.

[0011] Furthermore, a ball valve and a flow meter are provided on the pipeline, and an optical rainfall sensor is placed under the spray pipe.

[0012] Furthermore, the pipeline is a PVC hard pipe.

[0013] Preferably, the island morphology and stratum structure simulation system comprises a simulation tank, and water outlets are respectively arranged on both sides of the simulation tank;

[0014] The simulation tank is divided into seawater-filled areas on both sides and an island-reef morphology and stratigraphic structure area in the middle by two transparent partitions. The front panel of the simulation tank located in the island-reef morphology and stratigraphic structure area is provided with array-distributed sampling holes for sampling by the sampler.

[0015] The diameter of the sampling hole is 3mm, and the distance between two adjacent sampling holes is 2.5cm.

[0016] The bottom of the permeable wall partition is provided with array-distributed water holes, and there are protrusions above the water holes. The water holes are inclined downward from the seawater-filled area to the island reef morphology and stratum structure area;

[0017] The diameter of the water holes is 3mm, and the interval between adjacent water holes is 7mm.

[0018] The seawater-filled area can be filled with self-made simulated seawater, which can be used in conjunction with the island and reef morphology and stratum structure area to simulate the actual island and reef environment;

[0019] The island and reef morphology and stratigraphic structure area can be filled in layers with calcareous fine sand samples that have been treated with similar grading and scaling to the top, and each layer is compacted separately. According to the test needs, calcareous fine sand samples that have been treated differently can be selected to flexibly control the key hydrogeological parameters such as the porosity and permeability of each stratum in the simulated island and reef, so that it can better simulate the islands and reefs under natural conditions and is not limited to one type.

[0020] Furthermore, the bottom of the simulation tank is provided with a plurality of grooves matching the transparent wall partition, and the top of the transparent wall partition is fixed by a limit clamp. The groove can fix the bottom of the transparent wall partition, and the top of the transparent wall partition can adjust the inclination of the transparent wall partition by moving the limit clamp, so as to simulate different island and reef forms.

[0021] Furthermore, the water outlet is connected to a rubber hose, a water stop clamp is provided on the rubber hose, and a water storage bucket is placed under the hose.

[0022] Furthermore, the sampler includes a needle and a needle tube, the needle is inserted into the island reef morphology and stratigraphic structure area through the sampling hole, the needle tube extends through the sampling hole, and the needle tube and the sampling hole are relatively sealed.

[0023] Preferably, the experimental observation and testing system includes an ultraviolet spectrophotometer, a Manta water quality sensor, a data collector, and a computer;

[0024] The Manta water quality sensor is electrically connected to the data collector, and the ultraviolet spectrophotometer and the data collector are electrically connected to the computer; the data collector collects water sample data in the island morphology and stratigraphic structure simulation system through the Manta water quality sensor, and the ultraviolet spectrophotometer collects water sample data taken out during the test process.

[0025] The present invention also provides a method for conducting a groundwater desalination model test using the system described in the above technical solution, comprising the following steps:

[0026] (1) Add deionized water to the artificial rainfall system and adjust the simulated rainfall according to the test requirements;

[0027] (2) Fix the artificial rainfall system directly above the island morphology and stratum structure simulation system, and turn on the artificial rainfall system to simulate rainfall;

[0028] (3) During the rainfall process, the experimental observation test system was used to collect relevant data on water samples from various parts of the island morphology and stratigraphic structure simulation system, and the data were collated and compared to explore the morphological change patterns and evolution processes of freshwater lenses in simulated islands and reefs of different stratigraphic layers and morphologies under the action of rainfall recharge of different intensities.

[0029] Specifically for the relevant structure, the test method includes the following steps:

[0030] ① Add deionized water to the water tank of the artificial rainfall system, adjust the flow of the ball valve and the pressure provided by the air pump according to the test requirements, and check whether the sprinkler head and other components can work normally;

[0031] ② Use grooves and limit clamps to fix the through-wall partition in the simulation tank according to the position and inclination angle required by the test, and separate the simulation tank into a seawater-filled area and an island reef morphology and stratum structure area;

[0032] ③ Add calcareous fine sand samples with similar grading and scale processing to simulate islands and reefs in the island and reef morphology and stratigraphic structure area, and fill them in layers to the top. At the same time, bury the needle of the sampler in the adjacent island and reef strata according to the location of the sampling hole. The end of the buried calcareous sand can be wrapped with gauze to prevent the entry of calcareous sand particles. The other end is connected to the needle tube and extended from the sampling hole. The gap between the needle tube and the sampling hole is filled with glue. The calcareous fine sand sample is compacted separately after each layer is filled;

[0033] ④ Make your own seawater, and then use the Manta water quality sensor to measure the conductivity, chloride ion concentration and other water quality parameters of the homemade seawater;

[0034] ⑤ Slowly add self-made seawater to the seawater-filled area to the outlet position, let it stand for one day to saturate the calcareous fine sand samples in the island reef morphology and stratum structure area, and then continue to add self-made seawater to the outlet position;

[0035] ⑥Fix the sprinkler pipe just above the island and reef morphology and stratum structure area, and turn on the water pump to simulate rainfall;

[0036] ⑦ During the experiment, the Manta water quality sensor in the experimental observation and test system was used to monitor the conductivity and chloride ion concentration of the homemade seawater in the seawater-filled area and the drainage water in the water storage barrel; the water samples to be tested were taken out from the sampling holes at different positions at regular intervals, and the conductivity and chloride ion concentration of the water samples were measured using an ultraviolet spectrophotometer; the total rainfall during the experiment was recorded using an optical rain sensor; the data was sorted and compared with the initial conductivity and chloride ion concentration of the homemade seawater, and the relationship between the conductivity, chloride ion concentration and rainfall intensity and rainfall time was analyzed, and the morphological change law and evolution process of the freshwater lens of simulated islands and reefs of different strata and morphology under the action of rainfall recharge of different intensities were explored.

[0037] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a groundwater desalination model test system and method, which has the following beneficial effects:

[0038] In the present invention, calcareous fine sand samples with similar grading and scale processing are added to the island and reef morphology and stratigraphic structure area to simulate the island and reef, and artificial seawater is added to the seawater filling area to simulate the marine environment. An artificial rainfall simulation system is used to simulate the natural rainfall process, and water samples at different positions are collected at different times through the sampling holes on the front side panel of the island and reef morphology and stratigraphic structure area, and parameters such as conductivity and chloride ion concentration are analyzed. The present invention can simulate the desalination and conservation process of coral islands and reefs under different rainfall intensities, different island and reef morphologies, and different stratigraphic structures. The experiment is intuitive and clear, simple to operate, and easy to control, and is suitable for the study of the desalination and conservation mechanism of island and reef groundwater. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0040] Figure 1 It is a connection block diagram of the overall system of the present invention;

[0041] Figure 2 It is a schematic diagram of the structure of the overall system of the present invention;

[0042] Figure 3 This is a schematic diagram of the artificial rainfall system structure;

[0043] Figure 4 It is a structural diagram of the island morphology and stratum structure simulation system;

[0044] Figure 5 This is a schematic diagram of the island and reef morphology structure of Example 1;

[0045] Figure 6 This is a schematic diagram of the stratum structure of Example 1;

[0046] Figure 7 This is a schematic diagram of the island and reef morphology structure of Example 2;

[0047] Figure 8 This is a schematic diagram of the stratum structure of Example 2;

[0048] Fig. 9 It is a schematic diagram of the structure of the through-wall partition;

[0049] Fig.10 It is a schematic diagram of the structure of the water-permeable hole on the through-wall partition;

[0050] Fig.11 It is a schematic diagram of the structure of the limit clamp;

[0051] Fig.12 Connection diagram of the test system for experimental observation;

[0052] Fig.13 It is a schematic diagram of the structure of the sampler;

[0053] In the figure, 1. artificial rainfall system; 101. water storage tank; 102. PVC hard pipe; 103. water pump; 104. ball valve; 105. flow meter; 106. sprinkler pipe; 107. air pump; 108. sprinkler head; 109. optical rainfall sensor; 2. island morphology and stratigraphic structure simulation system; 201. simulation tank; 202. water outlet; 203. rubber hose; 204. water stop clamp; 205. sampling hole; 206. groove; 207. through-wall partition; 208. water storage barrel; 209. limit clamp; 210. sampler; 211. homemade seawater and drainage water; 212. taken water sample; 3. experimental observation and testing system; 301. ultraviolet spectrophotometer; 302. Manta water quality sensor; 303. data collector; 304. computer. DETAILED DESCRIPTION

[0054] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Example 1

[0056] As attached Figure 1-6 As shown in 9-13, the present invention discloses an island reef groundwater desalination model test system taking into account the changes in island morphology and stratum structure, including: an artificial rainfall system 1, an island morphology and stratum structure simulation system 2, and an experimental observation test system 3;

[0057] The artificial rainfall system 1 includes a water storage tank 101, a PVC hard pipe 102, a water pump 103, a ball valve 104, a flow meter 105, a sprinkler pipe 106, an air pump 107, a sprinkler head 108, and an optical rainfall sensor 109;

[0058] The positions and connection relationships are as follows: a water pump 103 is placed in the water tank 101, the water pump 103 is connected to the PVC hard pipe 102, and then the air pump 107 for providing pressure, the ball valve 104 for controlling the flow rate, the flow meter 105 for monitoring the flow rate and recording the flow rate are connected in sequence through the PVC hard pipe 102, and then the spray pipe 106 is passed. The spray pipe 106 is provided with an air pump 107 and a spray head 108. Except for the spray head 108 and the optical rainfall sensor 109, the connection method of all other components is direct plug-in connection. The spray head 108 is an embedded connection, and the optical rainfall sensor 109 is placed just below the left side of the spray pipe 106.

[0059] In this structure, the water tank 101 is filled with deionized water, and the air pump 107 can provide a pressurized or stabilized pressure environment during the test. The air pump 107 above the spray pipe 106 can make the spray range of the spray head 108 controllable, and various models of spray heads 108 can be selected as needed without considering the minimum pressure requirement. The optical rain sensor 109 is used to measure the rainfall during the test.

[0060] The island morphology and stratum structure simulation system 2 includes a simulation tank 201, a water outlet 202, a rubber hose 203, a water stop clamp 204, a sampling hole 205, a groove 206, a through-wall partition 207, a water storage bucket 208, a limit clamp 209, and a sampler 210;

[0061] The positions and connection relationships are as follows: water outlets 202 are arranged on the left and right sides of the simulation tank 201, a rubber hose 203 is wrapped around the outside of the water outlet 202, and the water inlet and outlet are controlled by a water stop clamp 204 arranged on the rubber hose 203, and a water storage bucket 208 is placed below the water outlet 202 to store the drainage water during the test; the simulation tank 201 is divided into three areas by a through-wall partition 207, with seawater-filled areas on both sides and an island-reef morphology and stratigraphic structure area in the middle; in addition, a sampling hole 205 is arranged on the front panel of the island-reef morphology and stratigraphic structure area of ​​the simulation tank 201, and a sampler 210 extends into the simulation tank 201 through the sampling hole 205 for sampling, and a plurality of grooves 206 for placing the through-wall partition 207 are arranged at the bottom of the simulation tank 201, and the intervals of the grooves 206 can be set to 5 cm;

[0062] The sampling holes 205 are distributed in an array, and the diameter can be set to 3mm. The interval between two adjacent sampling holes 205 can be set to 2.5cm. The width of the permeable partition 207 is equal to the inner width of the simulation tank 201. The upper part is a watertight area, and the lower part is a watertight area. The watertight area is provided with watertight holes. The watertight holes are downwardly inclined from the seawater-filled area to the island and reef morphology and stratigraphic structure area, and there are protrusions above the watertight holes to prevent the smaller-sized calcareous sand particles from overflowing the island and reef morphology and stratigraphic structure area with the water flow. The watertight holes are distributed in an array, and each diameter can be set to 3mm. The interval between adjacent watertight holes can be set to 7mm.

[0063] The bottom of the through-wall partition 207 is placed in the groove 206 to fix its lower part, and the upper part is limited to move backward by the limit clamp 208. Different island and reef forms can be simulated by adjusting the position and inclination angle of the through-wall partition 207. The island and reef forms and stratum structures in this embodiment are shown in the attached figure. Figure 5-6 As shown;

[0064] The simulation tank 201 is preferably made of a water-impermeable transparent material;

[0065] In this structure, the seawater filling area can accept self-made seawater, and cooperate with the island and reef morphology and stratigraphic structure area to simulate the actual island and reef environment. The island and reef morphology and stratigraphic structure area can be filled in layers with calcareous fine sand samples that have been processed with similar grading and scale reduction to the top, and each layer is compacted separately. According to the needs of the test, calcareous fine sand samples that have been processed differently can be selected, so that the key hydrogeological parameters such as the porosity and permeability of each stratum in the simulated island and reef can be flexibly adjusted, so that it can better simulate the islands and reefs under natural conditions and is not limited to one type;

[0066] The sampler 210 is composed of a needle and a needle tube. The needle is buried in two adjacent strata according to the position of the sampling hole 205 and extends into the middle of the simulated island reef. The needle tube extends through the sampling hole 205, and the gap between the sampler 210 and the sampling hole 205 is sealed with glue. Sampling can be performed at different positions at different times during the test.

[0067] The experimental observation and testing system 3 includes an ultraviolet spectrophotometer 301, a Manta water quality sensor 302, a data collector 303, and a computer 304;

[0068] The positional relationship and connection relationship are as follows: Manta water quality sensor 302 is placed in the seawater filling area and water storage barrel 208, and is connected to data collector 303, and data collector 303 and UV spectrophotometer 301 are connected to computer 304;

[0069] The ultraviolet spectrophotometer 301 is used to detect the conductivity value and chloride ion concentration of the water sample taken by the sampler 210 during the test, and transmit the data to the computer 304; the Manta water quality sensor 302 is used to monitor the conductivity value, chloride ion concentration and other water quality parameters of the water samples in the upper and lower parts of the seawater filling area and the water storage barrel 208 in real time, and collect real-time data through the data collector 303 and transmit it to the computer 304.

[0070] The specific method of conducting experiments using this system includes the following steps:

[0071] ① Add deionized water to the water storage tank 101 in the artificial rainfall system 1, and adjust the flow rate of the ball valve 104 and the pressure provided by the air pump 107 according to the test requirements, and check whether the sprinkler head 108 and other components can work normally;

[0072] ② Using the groove 206 and the limit clamp 209, the through-wall partition 207 is fixed in the simulation tank 201 at the position and inclination angle required by the test, and the simulation tank 201 is divided into a seawater-filled area and an island reef morphology and stratum structure area;

[0073] ③ Add calcareous fine sand samples with similar grading and scale processing to simulate islands and reefs in the island and reef morphology and stratigraphic structure area, and fill them in layers to the top. At the same time, bury the needle of the sampler 210 in the adjacent island and reef strata according to the position of the sampling hole 205. One end of the buried calcareous sand can be wrapped with gauze to prevent the calcareous sand particles from entering the sampler 210. The other end is connected to the needle tube and extends out of the sampling hole 205. The gap between the needle tube and the sampling hole 205 is filled with glue. The calcareous fine sand sample is compacted separately after each layer is filled;

[0074] ④ Self-made seawater, using Manta water quality sensor 302 to measure the conductivity value, chloride ion concentration and other water quality parameters of the self-made seawater 211;

[0075] ⑤ Slowly add the self-made seawater to the seawater filling area to the position of the water outlet 202, let it stand for one day to saturate the calcareous fine sand sample in the island reef morphology and stratum structure area, and then continue to add the self-made seawater to the position of the water outlet 202;

[0076] ⑥ Fix the sprinkler pipe 106 just above the island reef morphology and stratum structure area, and turn on the water pump 103 to simulate rainfall;

[0077] ⑦ During the experiment, the Manta water quality sensor 302 in the experimental observation and testing system 3 is used to monitor the conductivity and chloride ion concentration of the homemade seawater in the seawater-filled area and the drainage water 211 in the water storage barrel 208; the water samples 212 to be tested are taken out from the sampling holes 205 at different positions at regular intervals, and the conductivity and chloride ion concentration of the taken water samples 212 are measured using the ultraviolet spectrophotometer 301; the total rainfall during the experiment is recorded using the optical rainfall sensor 109; the data is sorted and compared with the initial conductivity and chloride ion concentration of the homemade seawater, and the relationship between the conductivity, chloride ion concentration and rainfall intensity and rainfall time is analyzed, so as to explore the morphological change law and evolution process of the freshwater lens of simulated islands and reefs of different strata and morphology under the action of rainfall replenishment of different intensities.

[0078] Example 2

[0079] The difference from Example 1 is that the island and reef morphology and stratum structure in this embodiment are as shown in the attached Figure 7-8 shown.

[0080] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0081] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A groundwater desalination model test system, characterized in that: include: Artificial rainfall system, island morphology and stratum structure simulation system and experimental observation and testing system; The artificial rainfall system simulates natural precipitation falling into the island morphology and stratum structure simulation system, and the experimental observation and testing system is connected to the island morphology and stratum structure simulation system.

2. A groundwater desalination model test system according to claim 1, characterized in that: The artificial rainfall system comprises a water pump and a spraying component connected in sequence through pipelines; The water pump is placed in the water storage tank; The spray component includes a spray pipe, a spray head is arranged on the spray pipe, and the spray head is located above the island morphology and stratum structure simulation system; The spray pipe and the pipeline are both connected with an air pump.

3. A groundwater desalination model test system according to claim 2, characterized in that: A ball valve and a flow meter are arranged on the pipeline, and an optical rainfall sensor is placed under the spray pipe.

4. A groundwater desalination model test system according to claim 2 or 3, characterized in that: The pipeline is a PVC hard pipe.

5. A groundwater desalination model test system according to claim 1, characterized in that: The island morphology and stratum structure simulation system comprises a simulation tank, and water outlets are respectively arranged on both sides of the simulation tank; The simulation tank is divided into seawater-filled areas on both sides and an island-reef morphology and stratigraphic structure area in the middle by two transparent partitions. The front panel of the simulation tank located in the island-reef morphology and stratigraphic structure area is provided with array-distributed sampling holes for sampling by the sampler. The lower part of the through-wall partition is provided with water-permeable holes distributed in an array, and there are protrusions above the water-permeable holes. The water-permeable holes are in a downwardly inclined structure from the seawater-filled area to the island reef shape and stratum structure area.

6. A groundwater desalination model test system according to claim 5, characterized in that: The bottom of the simulation tank is provided with a plurality of grooves matching the through-wall partition, and the top of the through-wall partition is fixed by a limiting clamp.

7. A groundwater desalination model test system according to claim 5, characterized in that: The water outlet is connected with a rubber hose, a water stop clamp is arranged on the rubber hose, and a water storage bucket is placed under the hose.

8. A groundwater desalination model test system according to claim 5, characterized in that: The sampler comprises a needle and a needle tube, the needle is inserted into the island reef morphology and stratum structure area through the sampling hole, the needle tube extends out through the sampling hole, and the needle tube and the sampling hole are relatively sealed.

9. A groundwater desalination model test system according to claim 1, characterized in that: The experimental observation and testing system includes an ultraviolet spectrophotometer, a Manta water quality sensor, a data collector, and a computer; The Manta water quality sensor is electrically connected to the data collector, and the ultraviolet spectrophotometer and the data collector are electrically connected to the computer; the data collector collects water sample data in the island morphology and stratigraphic structure simulation system through the Manta water quality sensor, and the ultraviolet spectrophotometer collects water sample data taken out during the test process.

10. A method for conducting a groundwater desalination model test using the system according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Add deionized water to the artificial rainfall system and adjust the simulated rainfall according to the test requirements; (2) Fix the artificial rainfall system directly above the island morphology and stratum structure simulation system, and turn on the artificial rainfall system to simulate rainfall; (3) During the rainfall process, the experimental observation test system was used to collect relevant data on water samples from various parts of the island morphology and stratigraphic structure simulation system, and the data were collated and compared to explore the morphological change patterns and evolution processes of freshwater lenses in simulated islands and reefs of different stratigraphic layers and morphologies under the action of rainfall recharge of different intensities.

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