Flow velocity signal generating device and borehole underground water flow velocity measuring system and method

Abstract

The invention belongs to the technical field of water flow velocity measurement, and discloses a flow velocity signal generation device and a borehole underground water flow velocity measurement system and method. The flow velocity signal generating device provided by the invention comprises a solute supply device and at least two flow velocity devices, wherein each flow velocity device comprises a floral tube, an upper bottom plate cover, a lower bottom plate cover and a liquid stirrer; the borehole underground water flow velocity measuring system comprises a flow velocity signal detecting and processing device and a flow velocity signal generating device. The drill hole underground water flow velocity is calculated by combining the solute concentration information in the floral tube obtained through detection, the size information of the floral tube and the concentration of the solute injected into the flow velocity device located in the feeding hole by the solute supply device. The underground water flow velocity measuring device can measure the underground water flow velocity of clean underground water which is extremely slow in flow velocity and basically free of suspended particles, the device can adapt to a narrow space in a drill hole, the measuring range meets the underground water seepage flow velocity measuring requirement, and it is ensured that the measuring process is environmentally friendly.

Description

Technical Field

[0001] The present invention belongs to the technical field of water flow velocity measurement, and more specifically, relates to a flow velocity signal generating device, a borehole groundwater flow velocity measurement system and a method. Background Art

[0002] The main methods for measuring water flow velocity include propeller flowmeter, Doppler flowmeter, ultrasonic flowmeter, imaging technology flowmeter, photoelectric flowmeter, and measuring groundwater flow velocity and direction by radioactive isotopes (radioactive gamma meter). However, unlike the general application of water flow velocity measurement, the space in the borehole is relatively small, the diameter of the borehole is generally 63mm-159mm or less, and the groundwater flow velocity is extremely slow, such as the groundwater infiltration velocity of porous aquifers is several meters / day (0.01mm / s) or less. At home and abroad, the three methods that are currently practical in the field of borehole groundwater flow velocity and direction measurement are limited to imaging technology flowmeter, radioactive gamma meter and photoelectric flowmeter.

[0003] However, the existing borehole groundwater flow rate measurement scheme has the following disadvantages: (1) The imaging technology flow meter uses suspended particles in water to image and measure the groundwater flow rate through image recognition technology. However, groundwater is generally very clean and there are few suspended particles that can meet the imaging requirements, which greatly affects its practicality; (2) The gamma meter using radioactive material tracing method measures the groundwater infiltration flow rate. The commonly used tracer is radioactive I131 (half-life 8.3 days), which is extremely harmful to human safety and groundwater pollution. It will cause a series of environmental problems after use. At present, the country has expressly prohibited any use of radioactive isotope tracing methods; (3) The equipment of the photoelectric flow meter requires a large space, and the photoelectric flow meter is limited by the sensor principle and structure and can only measure the design flow rate of a certain point in the underground aquifer.

[0004] How to measure the groundwater flow rate of clean groundwater with extremely slow flow rate and basically no suspended particles, so that the equipment can adapt to the narrow space in the borehole, the range meets the requirements of groundwater infiltration flow rate measurement and ensure that the measurement process is green and environmentally friendly, is a topic that technicians in this field are concerned about and need to solve. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a flow velocity signal generating device, a borehole groundwater flow velocity measuring system and method, so as to measure the groundwater flow velocity of clean groundwater with extremely slow flow velocity and basically no suspended particles, so that the equipment can adapt to the narrow space in the borehole, the measuring range meets the requirements for groundwater infiltration flow velocity measurement and ensures that the measurement process is green and environmentally friendly.

[0006] In a first aspect, the present invention provides a flow rate signal generating device, comprising: a solute supply device and at least two flow rate devices; one of the flow rate devices is located in a delivery hole, and the other flow rate devices are located in an observation hole;

[0007] The solute supply device is used to provide solute to inject the solute into the flow meter located in the injection hole;

[0008] The flow meter comprises a flower tube, upper and lower bottom plate covers and a liquid agitator; a plurality of water-permeable holes are distributed on the tube wall of the flower tube; the upper and lower bottom plate covers are located at the upper and lower ends of the flower tube along the axial direction, and are used to prevent the solute from diffusing along the axial direction of the flower tube; the liquid agitator is used to stir the solute in the flower tube to make the solute in the flower tube uniform;

[0009] The flow meter located in the delivery hole is used to contain uniform solutes and provide a channel for groundwater to flow in a direction perpendicular to the axial direction of the flower tube;

[0010] The flow meter located in the observation hole is used to contain groundwater located at the observation hole.

[0011] Preferably, the solute supply device comprises a solute pool and a peristaltic pump; the solute pool is used to provide solute; the peristaltic pump is used to control the solute flow rate and transport the liquid at a preset speed.

[0012] Preferably, the solute supply device is a solute quantitative delivery component, and the solute quantitative delivery component is installed in the flower tube or set on the ground.

[0013] Preferably, the outer diameter of the floral tube is less than 50 mm.

[0014] In a second aspect, the present invention provides a borehole groundwater flow velocity measurement system, comprising: a flow velocity signal detection and processing device, and the above-mentioned flow velocity signal generating device;

[0015] The flow rate signal detection and processing device includes a sensor and a data processing unit;

[0016] The sensor is located in the flower tube in the flow rate signal generating device, and is used to detect and obtain the solute concentration information in the flower tube;

[0017] The data processing unit is used to calculate the borehole groundwater flow rate by combining the solute concentration information, the size information of the flower tube, and the solute concentration injected into the flow meter located in the injection hole by the solute supply device in the flow rate signal generating device.

[0018] Preferably, the sensor is one or more of an ion electrode sensor, a conductivity sensor, and a spectrophotometric sensor.

[0019] Preferably, when the flower tube is a cylindrical casing, the data processing unit calculates the borehole groundwater flow rate in the following manner:

[0020]

[0021] Where v is the groundwater velocity in the borehole, R is the radius of the tube, C(t) is the solute concentration in the tube measured by the sensor in the flowmeter located in the observation hole at time t, and C m is the integration constant, C0 is the first constant;

[0022] Among them, C0 is expressed as follows:

[0023]

[0024] Wherein, L is the length of the floral tube along the axial direction, m0 is the solute concentration injected by the solute supply device into the flow meter located in the delivery hole, q is the flow rate of the solute, and c is the concentration of the solute.

[0025] Preferably, the borehole groundwater velocity determination system further comprises: a human-computer interaction device;

[0026] The human-computer interaction device is connected to the flow rate signal detection and processing device, and the human-computer interaction device is used to display the borehole groundwater flow rate and perform human-computer interaction control.

[0027] In a third aspect, the present invention provides a method for measuring the flow rate of groundwater in a borehole, which is implemented by using the above-mentioned system for measuring the flow rate of groundwater in a borehole. The method for measuring the flow rate of groundwater in a borehole comprises the following steps:

[0028] A flow meter is installed in each of the plurality of boreholes serving as delivery holes and observation holes, and a sensor is installed in the flow meter;

[0029] Using a solute supply device to inject solute into a flow meter located in the injection hole;

[0030] The solute concentration information in the flower tube of each flow meter is obtained by using the sensor in the flow meter, and transmitted to the data processing unit;

[0031] The data processing unit calculates the borehole groundwater flow rate by combining the solute concentration information, the size information of the flower tube, and the solute concentration injected into the flow meter located in the injection hole by the solute supply device.

[0032] Preferably, the borehole groundwater flow rate determination method further comprises: using a human-computer interaction device to display the borehole groundwater flow rate, and using the human-computer interaction device to perform human-computer interaction control.

[0033] One or more technical solutions provided in the present invention have at least the following technical effects or advantages:

[0034] For groundwater flowing slowly in the narrow space of a borehole, how to generate signals to characterize the changes in groundwater flow velocity, so as to construct an effective flow velocity signal generating device, is the key technology that should be solved first. After determining the flow velocity signal generating device, designing a matching and simple and practical groundwater flow velocity calculation method is another key technology. Aiming at the demand of groundwater flow rate measurement, the present invention designs a flow rate signal generating device including a solute supply device and at least two flow meters. The flow meter only includes a flower tube, upper and lower bottom plate covers and a liquid agitator. The device is small in size and can adapt to the narrow space in the borehole. The solute is provided by the solute supply device and injected into the flow meter located in the injection hole. Correspondingly, the present invention adopts a chemical composition detection method with extremely low detection accuracy and lower concentration limit (lower concentration limit ppm level). The water flow exchange volume (flow rate) in the borehole is extremely small and the concentration difference can be detected. Therefore, the range of groundwater flow rate detection using the flow rate signal generating device provided by the present invention is from tens of centimeters / day to several meters / day. The equipment range can meet the special requirements of groundwater infiltration flow rate measurement, and the flow rate of groundwater with extremely slow flow rate can be measured. After designing the flow rate signal generating device, the borehole groundwater flow rate can be measured in combination with the flow rate signal detection and processing device. The present invention combines the solute concentration information obtained by the sensor detection, the size information of the flower tube, and the solute concentration injected into the flow meter located in the injection hole by the solute supply device in the flow rate signal generating device, and can calculate the borehole groundwater flow rate. That is, the present invention provides a solution for measuring the borehole groundwater flow rate that is different from the prior art. In addition, compared with the imaging technology flow meter, the present invention can measure the flow rate of clean groundwater without suspended particles; compared with the gamma meter of the radioactive material tracing method, the measurement process of the present invention is green and pollution-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic structural diagram of a flow velocity signal generating device provided in Example 1 of the present invention;

[0036] Figure 2 A schematic diagram of solute equilibrium in a borehole groundwater flow rate measurement system provided in Example 2 of the present invention.

[0037] Among them, 1-flow rate device, 2-solute supply device, 3-sensor;

[0038] 11- flower tube, 12- upper and lower bottom plate covers, 13- liquid agitator;

[0039] 21-solute tank, 22-peristaltic pump. DETAILED DESCRIPTION

[0040] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0041] Embodiment 1:

[0042] Embodiment 1 provides a flow rate signal generating device, see Figure 1 , including: a solute supply device 2 and at least two flowmeters 1; one of the flowmeters 1 is located in the delivery hole, and the other flowmeters 1 are located in the observation hole. The flowmeter 1 includes a flower tube 11, upper and lower bottom plate covers 12 and a liquid agitator 13; a plurality of water-permeable holes are distributed on the tube wall of the flower tube 11; the upper and lower bottom plate covers 12 are located at the upper and lower ends of the flower tube 11 along the axial direction, and are used to prevent the solute from diffusing along the axial direction of the flower tube 11, so as to improve the accuracy and reliability of solute concentration detection; the liquid agitator 13 is used to stir the solute in the flower tube 11, so as to make the solute in the flower tube 11 uniform.

[0043] The solute supply device 2 is used to provide solutes to inject the solutes into the velocity meter 1 located in the delivery hole. The velocity meter 1 located in the delivery hole is used to contain uniform solutes and provide a channel for groundwater to flow along the axial direction perpendicular to the flower tube 11. The velocity meter 1 located in the observation hole is used to contain groundwater located at the observation hole.

[0044] For example, the solute supply device 2 includes a solute pool 21 and a peristaltic pump 22; the solute pool 21 is used to provide solute; the peristaltic pump 22 is used to control the solute flow rate and transport the liquid at a preset speed.

[0045] For another example, the solute supply device is a solute quantitative delivery component, and the solute quantitative delivery component is installed in the flower tube 11 or set on the ground.

[0046] Wherein, the outer diameter of the flower tube 11 is less than 50 mm.

[0047] Example 1 In response to the demand for groundwater flow rate measurement, a flow rate signal generating device including a solute supply device and at least two flow meters is designed. The flow meter only includes a flower tube, upper and lower bottom plate covers and a liquid agitator. The device is small in size and can adapt to the narrow space in the borehole. The solute is provided by the solute supply device and injected into the flow meter located in the injection hole. The corresponding present invention adopts a chemical composition detection method with extremely low detection accuracy and lower concentration limit (lower concentration limit ppm level). The water flow exchange volume (flow rate) in the borehole is extremely small and the concentration difference can be detected. Therefore, the range of groundwater flow rate detection using the flow rate signal generating device provided by the present invention is from tens of centimeters / day to several meters / day. The equipment range can meet the special requirements of groundwater infiltration flow rate measurement, and the flow rate of groundwater with extremely slow flow rate can be measured.

[0048] On the basis of Example 1, the present invention further provides a borehole groundwater flow rate measurement system, which is described below with reference to Example 2.

[0049] Embodiment 2:

[0050] Example 2 provides a borehole groundwater flow rate measurement system, including: a flow rate signal detection and processing device, and a flow rate signal generating device as provided in Example 1.

[0051] Among them, the flow rate signal detection and processing device includes a sensor and a data processing unit; the sensor is located in the flower tube in the flow rate signal generating device, and is used to detect and obtain the solute concentration information in the flower tube; the data processing unit is used to combine the solute concentration information, the size information of the flower tube, and the solute concentration injected into the flow meter located in the injection hole by the solute supply device in the flow rate signal generating device to calculate the borehole groundwater flow rate.

[0052] Wherein, the sensor is one or more of an ion electrode sensor, a conductivity sensor, and a spectrophotometric sensor. That is, the installed sensor can be one or more types of sensors to adapt to groundwater of different water qualities. For example, the concentration of chemical electrosolutes (NaCl / KCl) can be measured with a Cl electrode and a conductivity electrode, and the concentration of fluorescein sodium / rhodamine B can be measured with a spectrophotometer.

[0053] When the flower tube is a cylindrical casing, the data processing unit calculates the borehole groundwater flow rate in the following manner:

[0054]

[0055] Where v is the groundwater velocity in the borehole, R is the radius of the tube, C(t) is the solute concentration in the tube measured by the sensor in the flowmeter located in the observation hole at time t, and C m is the integration constant, C0 is the first constant.

[0056] Among them, C0 is expressed as follows:

[0057]

[0058] Wherein, L is the length of the floral tube along the axial direction, m0 is the solute concentration injected by the solute supply device into the flow meter located in the delivery hole, q is the flow rate of the solute, and c is the concentration of the solute.

[0059] In addition, the flower tube can also be replaced with different geometric shapes according to application requirements. By combining the geometric shape of the flower tube and establishing a differential equation through the law of conservation of mass, a calculation formula for the corresponding borehole groundwater flow rate can be obtained.

[0060] In a preferred embodiment, the borehole groundwater flow rate measurement system may further include: a human-computer interaction device; the human-computer interaction device is connected to the flow rate signal detection and processing device, and the human-computer interaction device is used to display the borehole groundwater flow rate and perform human-computer interaction control.

[0061] The measuring method of the present invention is described in detail below.

[0062] The groundwater infiltration velocity is generally slow. In the movement of groundwater solutes, the particle migration velocity of chemical diffusion is much smaller than the mechanical diffusion velocity, and the difference is often more than one order of magnitude. Therefore, when the velocity signal generator is placed in the borehole, the following reasonable assumptions can be made:

[0063] (1) Ignore the influence of chemical diffusion and only consider mechanical diffusion;

[0064] (2) The outer wall of the flower tube of the flow velocity signal generating device is quite thin and its volume can be ignored;

[0065] (3) The liquid agitator makes the solute concentration in the flower tube reach uniformity very quickly without causing the solution to overflow;

[0066] (4) Both ends of the flower tube are closed;

[0067] (5) The solute is stably injected into the flower tube and the solute concentration in the flower tube is consistent under the action of the liquid agitator.

[0068] See also Figure 1 , Figure 2 , flower tube volume V = πR 2 L, select the section F=2RL which is perpendicular to the groundwater flow direction. The groundwater inflow Q1 and outflow Q2 through the flower tube are equal, so Q1=Q2=vF, where v is the groundwater flow velocity.

[0069] In the Δt time period, the mass of solute M0 flowing through the flower tube is:

[0070] M0=Q1×C1(t)×Δt+m o ×Δt (1)

[0071] Where m0 is the solute concentration injected into the flow meter located in the injection hole by the solute supply device; C1(t) is the concentration of the solute in the groundwater flowing into the flower tube (this solute does not come from the solute supply device, but from the groundwater flowing from upstream).

[0072] In the Δt time period, the mass of solute flowing out through the flower tube M(t) is:

[0073] M(t)=C(t)×Q2×Δt=C(t)×v×F×Δt (2)

[0074] C(t) is the solute concentration in the flower tube detected by sensor 3 at time t.

[0075] In the Δt time period, the solute mass conservation equation in the flower tube is:

[0076] M(t)-M0=v×F×Δt×(C(t)-C1(t))-m o ×Δt (3)

[0077] Select appropriate solutes and assume that the solute concentration in groundwater is 0 (i.e. the background tracer concentration in groundwater is 0), so the above formula can be simplified to:

[0078]

[0079] Wherein, Δm=M(t)-M0, Δm is the difference between the mass of the solute flowing out through the flower tube and the mass of the solute flowing into the flower tube in the Δt time period.

[0080] By dividing both sides by the tube volume V, equation (4) can be simplified to:

[0081]

[0082] Where: C0 is a constant, and its value is as follows:

[0083]

[0084] Where: q is the solution flow rate, c is the solution concentration.

[0085] Formula (5) can be rewritten as:

[0086]

[0087] Where: C(t) is the solute concentration in the flower tube (at time t, which can be detected by sensor 3). m is the integral constant, which can be calculated according to different conditions. K is a constant, which is calculated as follows:

[0088]

[0089] By simplifying formula (7), the borehole groundwater velocity v is expressed as follows:

[0090]

[0091] The borehole groundwater flow rate can be calculated according to formula (9).

[0092] Example 2 is combined with a flow rate signal generating device and a flow rate signal detecting and processing device to measure the flow rate of groundwater in a borehole. The present invention combines the solute concentration information obtained by sensor detection, the size information of the flower tube, and the solute concentration injected into the flow meter located in the injection hole by the solute supply device in the flow rate signal generating device to calculate the groundwater flow rate in the borehole.

[0093] Example 2 provides a solution for measuring the flow rate of groundwater in a borehole that is different from the prior art.

[0094] Embodiment 3:

[0095] Embodiment 3 provides a method for measuring the flow rate of groundwater in a borehole, which is implemented by using the borehole groundwater flow rate measuring system provided in Embodiment 2. The method for measuring the flow rate of groundwater in a borehole provided in Embodiment 3 includes the following steps:

[0096] A flow meter is installed in each of the plurality of boreholes serving as delivery holes and observation holes, and a sensor is installed in the flow meter;

[0097] The solute is injected into the flow meter located in the injection hole by using the solute supply device;

[0098] The solute concentration information in the flower tube of each flow meter is obtained by using the sensor in the flow meter, and transmitted to the data processing unit;

[0099] The data processing unit calculates the borehole groundwater flow rate by combining the solute concentration information, the size information of the flower tube, and the solute concentration injected into the flow meter located in the injection hole by the solute supply device.

[0100] In addition, the method for measuring the borehole groundwater flow rate may also include: using a human-computer interaction device to display the borehole groundwater flow rate, and using the human-computer interaction device to perform human-computer interaction control.

[0101] Since the steps in the borehole groundwater flow rate measurement method provided in Example 3 correspond to the functions of each component in the borehole groundwater flow rate measurement system provided in Example 2, Example 3 can be understood by referring to the description of Example 2, which will not be repeated here.

[0102] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A flow velocity signal generating device, characterized in that: include: A solute supply device and at least two flow rate devices; one of the flow rate devices is located in the delivery hole, and the other flow rate devices are located in the observation hole; The solute supply device is used to provide solute to inject the solute into the flow meter located in the injection hole; The flow meter comprises a flower tube, upper and lower bottom plate covers and a liquid agitator; a plurality of water-permeable holes are distributed on the tube wall of the flower tube; the upper and lower bottom plate covers are located at the upper and lower ends of the flower tube along the axial direction, and are used to prevent the solute from diffusing along the axial direction of the flower tube; the liquid agitator is used to stir the solute in the flower tube to make the solute in the flower tube uniform; The flow meter located in the delivery hole is used to contain uniform solutes and provide a channel for groundwater to flow in a direction perpendicular to the axial direction of the flower tube; The flow meter located in the observation hole is used to contain the groundwater located at the observation hole.

2. The flow velocity signal generating device according to claim 1, characterized in that: The solute supply device comprises a solute pool and a peristaltic pump; the solute pool is used to provide solute; the peristaltic pump is used to control the solute flow rate and transport the liquid at a preset speed.

3. The flow velocity signal generating device according to claim 1, characterized in that: The solute supply device is a solute quantitative delivery component, and the solute quantitative delivery component is installed in the flower tube or arranged on the ground.

4. The flow velocity signal generating device according to claim 1, characterized in that: The outer diameter of the floral tube is less than 50 mm.

5. A borehole groundwater velocity measurement system, characterized in that: include: A flow velocity signal detection and processing device, and a flow velocity signal generating device as claimed in any one of claims 1 to 4; The flow rate signal detection and processing device includes a sensor and a data processing unit; The sensor is located in the flower tube in the flow rate signal generating device, and is used to detect and obtain the solute concentration information in the flower tube; The data processing unit is used to calculate the borehole groundwater flow rate by combining the solute concentration information, the size information of the flower tube, and the solute concentration injected into the flow meter located in the injection hole by the solute supply device in the flow rate signal generating device.

6. The borehole groundwater velocity measurement system according to claim 5, characterized in that: The sensor is one or more of an ion electrode sensor, a conductivity sensor, and a spectrophotometric sensor.

7. The borehole groundwater velocity measurement system according to claim 5, characterized in that: When the flower tube is a cylindrical casing, the data processing unit calculates the borehole groundwater flow rate in the following manner: Where v is the groundwater velocity in the borehole, R is the radius of the tube, C(t) is the solute concentration in the tube measured by the sensor in the flowmeter located in the observation hole at time t, and C m is the integration constant, C0 is the first constant; Among them, C0 is expressed as follows: Wherein, L is the length of the floral tube along the axial direction, m0 is the solute concentration injected by the solute supply device into the flow meter located in the delivery hole, q is the flow rate of the solute, and c is the concentration of the solute.

8. The borehole groundwater velocity measurement system according to claim 5, characterized in that: Also includes: Human-computer interaction device; The human-computer interaction device is connected to the flow rate signal detection and processing device, and the human-computer interaction device is used to display the borehole groundwater flow rate and perform human-computer interaction control.

9. A method for measuring the velocity of groundwater in a borehole, characterized in that: The method for measuring the borehole groundwater flow rate is implemented by using the borehole groundwater flow rate measuring system as described in any one of claims 5 to 8, and the borehole groundwater flow rate measuring method comprises the following steps: A flow meter is installed in each of the plurality of boreholes serving as delivery holes and observation holes, and a sensor is installed in the flow meter; The solute is injected into the flow meter located in the injection hole by using the solute supply device; The solute concentration information in the flower tube of each flow meter is obtained by using the sensor in the flow meter, and transmitted to the data processing unit; The data processing unit calculates the borehole groundwater flow rate by combining the solute concentration information, the size information of the flower tube, and the solute concentration injected into the flow meter located in the injection hole by the solute supply device.

10. The method for measuring the borehole groundwater flow rate according to claim 9, characterized in that: Also includes: The human-computer interaction device is used to display the borehole groundwater flow rate, and the human-computer interaction device is used to perform human-computer interaction control.

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