Method and device for measuring pressureless short-duration uniform flow in an advanced borehole

Abstract

The present application belongs to the technical field of engineering geological survey, and particularly relates to a method and equipment for measuring the flow of non-pressure short-time uniform flow in an advanced borehole, which uses thin-wall weirs with different shapes as a drainage device, and automatically triggers a water-contacting starting timing synchronous circuit at the bottom of a contact cylinder by water flow, to automatically obtain an uncorrected water-contacting starting time; then multiple miniature floating ball water level sensors are used to automatically record the water-contacting ending time in multiple directions, and the positions of the miniature floating ball water level sensors are defined as recording points of water flow into the cylinder, so that the multiple miniature water level sensors can directly and accurately record the water-contacting ending time, and the water-contacting starting time is corrected and the water-contacting ending time is calculated in multiple modes by a correction algorithm, to obtain the final accurate water flow value. The present application can overcome the problems of low measurement accuracy and inconvenience in the existing measurement technology.

Description

A method and equipment for measuring the flow rate of unpressurized short-time uniform water in advanced boreholes Technical Field

[0001] This invention belongs to the field of engineering geological exploration technology, and in particular relates to a method and equipment for measuring the flow rate of unpressurized short-time uniform water in advanced boreholes. Background Technology

[0002] In coal mine underground work, construction tunnels, and surface pre-drilling for water exploration, it is often necessary to accurately measure the water flow rate in the pre-drilled boreholes in order to further analyze the corresponding mine hydrogeological conditions, the water-rich conditions of the strata traversed by the tunnel, and to quantitatively evaluate the effectiveness of water exploration.

[0003] Currently, the main method involves directly collecting water using containers such as buckets, large and medium-sized mineral water bottles, and measuring cylinders, and recording the collection time with a stopwatch. This process is repeated several times and then averaged. However, this traditional method has several technical problems. First, due to the varying geometry of the vertical sections at the borehole openings and the influence of water flow velocity, the water flow patterns at the borehole openings are diverse. It is almost impossible to completely intercept the water flow by placing a measuring cylinder or similar container below or directly against the borehole opening, resulting in a large discrepancy between the collected water volume and the true value. Second, due to differences in individual physiological reaction times and subjective factors such as emotions and mental state, the start and end times recorded using a stopwatch or similar push-button recorder also have significant systematic errors, leading to low accuracy in the final water collection time value. Therefore, when precise measurement of water flow in pre-drilled boreholes is required, the only method currently used is to install orifice pipes, flanges, control valves, and liquid flow meters at the borehole opening. However, the location of pre-drilled borehole openings in coal mine roadway excavation faces and tunnel faces is dynamically changing as excavation progresses. This method is costly and can affect the excavation schedule. Therefore, water flow in pre-drilled boreholes is generally unsuitable for measurement using orifice pipes and liquid flow meters. Given these negative impacts and technical limitations, to conveniently and accurately measure water flow at the borehole opening, in-depth research into the hydrodynamic and electrical characteristics of water flow within the pre-drilled borehole, along with advanced sensor technology, is needed to propose new methods and equipment that do not affect the excavation schedule, offer convenient and accurate measurements, and provide intelligent display of results. Summary of the Invention

[0004] The technical problem solved by this invention is to provide a method and equipment for measuring the flow rate of unpressurized short-time uniform water in advanced boreholes, so as to overcome the problems of low measurement accuracy and inconvenience in existing measurement technologies.

[0005] The basic solution provided by this invention is: a method for measuring the flow rate of unpressurized short-time uniform water in advanced boreholes, comprising:

[0006] S1: Obtain the borehole data of the advanced borehole, fabricate the thin-walled weir diversion device, and install the thin-walled weir diversion device in the advanced borehole;

[0007] S2: Based on the preset unpressurized short-time uniform water flow model, determine whether the water flow in the advanced borehole is in an unpressurized short-time uniform water flow state;

[0008] S3: Prefabricate a measuring cylinder fixture, wherein a sensing control circuit for initiating water intake time is installed at the center of the bottom of the measuring cylinder fixture; multiple miniature float water level sensors are evenly arranged around the inner wall of the measuring cylinder fixture.

[0009] S4: When the water flow in the pre-drilled hole is in a state of pressureless short-term uniform water flow, the measuring cylinder is placed at the water drop point of the thin-walled weir diversion device to collect water. Based on the good conductivity of the flowing water, the induction control circuit at the center of the bottom of the measuring cylinder is activated to start recording the water collection start time. The water collection end time is independently recorded based on multiple micro float water level sensors. The independently recorded water collection end time is processed by intelligent statistical analysis to select the optimal mode for calculating the water collection end time and obtain the water collection end time correction value.

[0010] S5: Obtain the unpressurized short-time uniform water flow model, decompose the water flow motion of the unpressurized short-time uniform water flow into horizontal uniform deceleration motion and free fall motion with an initial velocity of V0, and construct a water inlet start time correction algorithm to obtain the water inlet start time correction value.

[0011] S6: Calculate the water flow rate in the advance borehole based on the water inlet start time correction value, the water inlet end time correction value, and the preset volume of the measuring cylinder.

[0012] Furthermore, the orifice data in S1 includes orifice diameter data and elevation angle data. The thin-walled weir diversion device includes at least two fastening support rods, a thin-walled weir, and a sealing rubber strip. The weir opening of the thin-walled weir is set according to a preset shape. One end of the fastening support rod is fixed to the top of the pre-drilled hole opening, and the other end is fixed to both sides of the thin-walled weir opening. The sealing rubber strip is located on the outer edge of the thin-walled weir and seals with the pre-drilled hole opening.

[0013] Furthermore, the preset pressureless short-time uniform water flow model in S2 is specifically constructed based on fluid mechanics theory, using the fact that the cross-sectional area of ​​the water passage in the pre-drilled borehole is less than or equal to 1 / 2 of the borehole cross-sectional area, the state of no fluid jets in the pre-drilled borehole, and the stable state of water flow to build a pressureless cylindrical uniform flow model.

[0014] Furthermore, the measuring cylinder fixture in S3 includes a cylindrical measuring cylinder, a controller, multiple miniature float level sensors, a sensing module, and a timer. The miniature float level sensors, sensing modules, and timers are all electrically connected to the controller. The sensing module is located at the bottom of the cylindrical measuring cylinder, and the top of the measuring cylinder has multiple graduation lines. The miniature float level sensors are located at the graduation lines. The sensing module generates a water-feeding start sensing signal when it senses water at the bottom of the cylindrical measuring cylinder. The controller controls the timer to start timing based on the water-feeding start sensing signal. Each miniature float level sensor generates a water-feeding end sensing signal when the water level in the cylindrical measuring cylinder reaches a graduation line. The controller controls the timer to stop timing based on the water-feeding end sensing signal.

[0015] Furthermore, the intelligent statistical analysis in S4 selects the optimal mode for calculating the end time of water collection, including the arithmetic average mode, the mode of removing the minimum value and then taking the average value, and the mode of removing the maximum value and then taking the average value.

[0016] Furthermore, the algorithm for correcting the water inlet start time in S5 is specifically as follows:

[0017] The short-time uniform flow of unpressurized water can be decomposed into horizontal uniformly decelerated motion with an initial velocity of v0 and free fall motion with an initial velocity of 0.

[0018] Using the formula for the free fall motion of a particle with an initial velocity of 0, H = 1 / 2gt 2 Calculate the free fall time t;

[0019] Construct a water inlet start time correction algorithm:

[0020]

[0021] Where, t′ i This indicates the precise start time of water collection when corrected to the aforementioned recording point. t1 represents the start time of water collection when the water flows to the bottom of the cylindrical graduated cylinder. The time t1 for the water to fall to the bottom of the cylindrical graduated cylinder is minus the free fall time of the water from the recording point to the bottom of the cylindrical graduated cylinder. This allows us to obtain the precise water collection start time t′1 when the water flows to the upper recording point of the cylindrical graduated cylinder, which is consistent with the defined water collection end time. H represents the height of the graduated cylinder fixture.

[0022] Furthermore, the formula for calculating the water flow rate of the pre-drilled borehole in S6 is as follows:

[0023]

[0024] Where t′1 is the correction value for the start time of water intake, t′2 is the correction value for the end time of water intake, V represents the volume of the measuring cylinder, and f represents the final measured water flow rate.

[0025] A device for measuring the flow rate of unpressurized, short-time uniform water in a pre-drilled borehole includes a thin-walled weir diversion device, a measuring cylinder fixture, and a data processing module. The thin-walled weir diversion device is located at the borehole opening to divert the water flowing out of the borehole. The measuring cylinder fixture is located at the point where the water falls after being diverted by the thin-walled weir diversion device. Multiple miniature float level sensors are evenly arranged around the inner wall of the measuring cylinder fixture. When the water flowing out of the pre-drilled borehole is in a state of unpressurized, short-time uniform flow, the measuring cylinder fixture activates a sensing control circuit at the center of its bottom region based on the good conductivity of the flowing water to start recording the start time of water intake. The data processing module is based on the independent flow rate of the multiple miniature float level sensors. The system records the water collection end time; the data processing module is used to acquire the water collection start time and multiple independently recorded water collection end times; the data processing module is also used to correct the acquired water collection start time according to a preset water collection start time correction algorithm to generate a corrected value for the water collection start time; the data processing module is also used to process the independently recorded water collection end times by selecting the optimal mode for calculating the water collection end time through intelligent statistical analysis to obtain the corrected value for the water collection end time; the data processing module is also used to calculate the water flow rate in the advanced borehole based on the corrected values ​​for the water collection start time and the water collection end time, as well as the preset volume of the measuring cylinder.

[0026] Furthermore, the thin-walled weir diversion device includes at least two fastening support rods, a thin-walled weir, and a sealing rubber strip. The weir opening of the thin-walled weir is set according to a preset shape. One end of the fastening support rod is fixed to the top of the pre-drilled hole opening, and the other end is fixed to both sides of the weir opening of the thin-walled weir. The sealing rubber strip is located on the outer edge of the thin-walled weir and seals with the pre-drilled hole opening.

[0027] Furthermore, the measuring cylinder device includes a cylindrical measuring cylinder, a controller, multiple miniature float level sensors, a sensing module, and a timer. The miniature float level sensors, sensing modules, and timers are all electrically connected to the controller. The sensing module is located at the bottom of the cylindrical measuring cylinder, and the top of the measuring cylinder has multiple graduation lines. The miniature float level sensors are located at the graduation lines. The sensing module generates a water-feeding start sensing signal when it senses water at the bottom of the cylindrical measuring cylinder. The controller controls the timer to start the water-feeding process based on the water-feeding start sensing signal. Each miniature float level sensor generates a water-feeding end sensing signal when the water level in the cylindrical measuring cylinder reaches a graduation line. The controller controls the timer to stop the timer based on the water-feeding end sensing signal. The controller also transmits the water-feeding start time and water-feeding end time recorded by the timer to the data processing module for water flow calculation.

[0028] The principle and advantages of this invention are as follows: Compared with traditional methods of using ordinary bottle or barrel openings and employing special flexible materials to tightly fit the cross-section at the opening for water collection, this invention uses thin-walled weirs of different shapes as diversion devices, cleverly solving the shortcomings of existing methods such as incomplete water collection, complex water collection methods, and difficulty in successful on-site operation; it also automatically triggers a timing synchronization circuit by having the water flow contact the bottom of the measuring cylinder, automatically acquiring the uncorrected water collection start time; furthermore, it uses multiple miniature float water level sensors to automatically record the water collection end time from multiple directions, and defines the position of the miniature float water level sensors as the recording point where the water flow enters the measuring cylinder, thus directly achieving accurate recording of the water collection end time by multiple miniature water level sensors; at the same time, this invention fully considers the existence of water collection timing extension errors in the water collection start time, and utilizes the fact that the unpressurized short-time uniform flow of water can be decomposed into horizontal uniformly decelerated motion with an initial velocity v0 and free fall motion with an initial velocity of 0, which can accurately correct the water collection start time to the water collection recording point H, and record the corrected time as t1. ′ Therefore, from the perspectives of fluid dynamics, intelligent water level sensor technology, and fluid parabolic kinematics, a method and device for intelligent measurement of pre-drilling water flow in unpressurized short-time uniform flow were proposed to overcome the problems of low measurement accuracy and inconvenience in existing measurement technologies. Attached Figure Description

[0029] Figure 1 is a flowchart of an embodiment of the present invention;

[0030] Figure 2 is a simulation diagram of the use of an embodiment of the present invention;

[0031] Figure 3 is a schematic diagram of the weir opening of the thin-walled weir in an embodiment of the present invention;

[0032] Figure 4 is a schematic diagram of the measuring cylinder fixture structure in an embodiment of the present invention;

[0033] Figure 5 is a functional block diagram of an embodiment of the present invention;

[0034] Figure 6 is a real-world diagram of advanced drilling in an embodiment of the present invention. Detailed Implementation

[0035] The following detailed description illustrates the specific implementation method:

[0036] The markings in the accompanying drawings include: 1. Pre-drilling hole; 2. Thin-walled weir diversion device; 201. Fastening support rod; 202. Weir opening; 3. Measuring cylinder fixture; 301. Cylindrical measuring cylinder; 302. Miniature float water level sensor; 303. Sensing module; 304. Handle one; 305. Handle two; 306. LCD display screen; 307. Control button.

[0037] Figure 6 shows images of advanced horizontal geological boreholes drilled in coal mines and construction tunnels. In this invention, the advanced borehole 1 is specifically defined as a borehole located on the vertical surface of a tunnel face, underground roadway excavation face, or underground mining face, with an elevation angle of less than 45°. The elevation angle can be negative, meaning there is a downward angle, but it is ensured that there is a short-term, uniform, and stable outflow or gush of runoff groundwater at the borehole opening. Generally, advanced borehole 1 is mostly a near-horizontal advanced borehole 1 with an elevation angle in the range of 5 to 10°.

[0038] The occurrence of runoff groundwater in a certain area ahead of construction is determined by accurately measuring hydrogeological parameters such as the velocity or flow rate of groundwater flowing out of the borehole. An example is shown in Figures 1 and 2: A method for measuring the flow rate of unpressurized short-time uniform water in an advanced borehole 1, comprising:

[0039] S1: Obtain the borehole data of the advanced borehole 1, fabricate the thin-walled weir diversion device 2, and install the thin-walled weir diversion device 2 inside the advanced borehole 1;

[0040] In this embodiment, the orifice data includes orifice diameter data and elevation angle data. The orifice diameter data is obtained based on the drill bit diameter or the actual measured orifice diameter. The elevation angle data is obtained through advanced geological drilling at the tunnel face and advanced water release engineering in coal mines. According to engineering practice, in order to ensure smooth slag discharge and water return, the advanced borehole 1 is designed with an elevation angle of 0° to 10°. In addition, due to the weight of the drill rod and drill bit, the drill bit will gradually descend during drilling. Even if the advanced borehole 1 is designed to be horizontal, the drill bit's opening elevation angle is not 0°. Therefore, it is actually designed to be 5° to 10° upward. Furthermore, the orifice data should also include the water passage cross-sectional area data, which is used to design the shape of the thin-walled weir diversion device 2.

[0041] The thin-walled weir diversion device 2 includes at least two fastening support rods 201, a thin-walled weir, and a sealing rubber strip. The weir opening 202 of the thin-walled weir is set according to a preset shape. One end of the fastening support rod 201 is fixed to the top of the opening of the pre-drilled hole 1, and the other end is fixed to both sides of the weir opening 202 of the thin-walled weir. The sealing rubber strip is located on the outer edge of the thin-walled weir and seals with the opening of the pre-drilled hole 1. For example, according to the size of the water flow cross section, the shape of the weir opening 202 of the thin-walled weir is designed to be triangular, and the overall shape of the thin-walled weir is semi-circular. The thin-walled weir is fixed to the top of the inner wall of the pre-drilled hole 1 by two fastening support rods 201, so that the water flowing out from the pre-drilled hole 1 gathers at the weir opening 202 of the thin-walled weir and flows out.

[0042] In other embodiments of this example, the weir opening 202 of the thin-walled weir can be designed in different shapes and with adjustable dimensions according to actual needs, such as triangular weir openings 202 of various sizes and rectangular weir openings 202 of various sizes as shown in Figure 3. Specifically, the thin-walled weir opening 202 shown in Figure 3a has a top width R, a depth of 2 / 3 * R, and an area R of the triangular weir opening 202. 2 / 3 corresponds to a 12L cylindrical container; the thin-walled weir shown in Figure 3b has a weir opening 202, a top width R, a depth 1 / 2·R, and an area R of the triangular weir opening 202. 2 / 4 corresponds to a 12L cylindrical container; the thin-walled weir shown in Figure 3c has a top width of 1 / 3·R, a depth of 2 / 3·R, and an area of ​​R for the rectangular weir. 2 / 4.5 corresponds to a 12L cylindrical container; as shown in Figure 3d, the top width of weir 202 is 1 / 3·R, the depth of weir 202 is 1 / 2·R, and the area of ​​rectangular weir 202 is R. 2 / 6 corresponds to an 8L cylindrical container; as shown in Figure 3e, the top width of weir 202 is 1 / 3·R, the depth of weir 202 is 2 / 3·R, and the area of ​​the triangular weir 202 is R. 2 / 9 corresponds to a 5L cylindrical container; as shown in Figure 3f, the top width of the weir 202 is 1 / 6·R, the depth of the weir 202 is 1 / 2·R, and the area of ​​the rectangular weir 202 is R2 / 12, corresponding to a 5L cylindrical container; the above-mentioned cylindrical container refers to the container used to receive the water flowing out from the thin-walled weir diversion device 2.

[0043] S2: Based on the preset unpressurized short-time uniform water flow model, determine whether the water flow in the advanced borehole 1 is in the state of unpressurized short-time uniform water flow.

[0044] In this embodiment, the preset unpressurized short-time uniform water flow model is determined based on the fluid model in fluid mechanics. The determination method is as follows: if the cross-sectional area of ​​the water passage at the borehole opening of the advanced borehole 1 is less than 1 / 2 of the borehole cross-sectional area, the advanced borehole 1 is in a state of no fluid ejection, and the water flow is in a stable state, then it is defined as an unpressurized short-time uniform water flow model. The state of no fluid ejection in the advanced borehole 1 means that there is no ejection phenomenon of gas, water, or other fluids in the advanced borehole 1. The stable water flow state is determined by the water surface line of the advanced borehole 1 based on the current water flow state determined by means of time-lapse photography, etc. Whether the water flow at the weir 202 is stable within a preset range, for example, the water surface line is stable within 5% before and after 30 seconds and the water flow pattern at the weir 202 remains stable; "no pressure" means that the water flow at each section from the bottom of the borehole to the opening of the pre-drill 1 is not full, which is called a no-pressure state. In this application, the cross-sectional area of ​​the water flow at the opening of the pre-drill 1 is less than 1 / 2 of the borehole cross-sectional area to determine whether it is in a no-pressure state; "short time" means that the water flow in the pre-drill 1 is affected by the subsequent supply source, and its flow trend is a general decreasing law, so it is called short time.

[0045] S3: Prefabricate a measuring cylinder fixture 3, with a sensing control circuit for the start of water intake time set at the bottom center of the measuring cylinder fixture 3; and evenly arrange multiple miniature float water level sensors 302 around the inner wall of the measuring cylinder fixture 3.

[0046] As shown in Figure 4, in this embodiment, the manufactured measuring cylinder fixture 3 includes a cylindrical measuring cylinder 301, a controller, multiple miniature float level sensors 302, a sensing module 303, and a timer. The miniature float level sensors 302, the sensing module 303, and the timer are all electrically connected to the controller. The sensing module 303 is located at the bottom of the cylindrical measuring cylinder 301. The top of the measuring cylinder has multiple graduation lines, and the miniature float level sensors 302 are located at the graduation lines. The sensing module 303 is used to generate a water-feeding start sensing signal when it senses water at the bottom of the cylindrical measuring cylinder 301. The controller controls the timer to start timing according to the water-feeding start sensing signal. Each miniature float level sensor 302 is used to generate a water-feeding end sensing signal when the water level in the cylindrical measuring cylinder 301 reaches the graduation line. The controller controls the timer to stop timing according to the water-feeding end sensing signal.

[0047] In this embodiment, four scale lines are set, and four miniature float level sensors 302 are used. The cylindrical measuring cylinder 301 is also provided with handle one 304 and handle two 305 on both sides. An LCD display 306 and control buttons 307 are set on handle one 304. Both the LCD display 306 and control buttons 307 are electrically connected to the controller. The LCD display 306 is used to display the timer reading, the final measured value, etc. The control buttons 307 include a power switch control button 307 and a correction parameter adjustment button.

[0048] S4: When the water flow in the pre-drill hole 1 is in a state of pressureless short-term uniform water flow, the measuring cylinder device 3 is placed at the water drop point of the thin-walled weir diversion device 2 to collect water. Based on the good conductivity of the flowing water, the induction control circuit at the bottom center area of ​​the measuring cylinder device 3 is activated to start recording the water collection start time. The water collection end time is independently recorded based on multiple micro float water level sensors 302. The independently recorded water collection end time is processed by intelligent statistical analysis to select the optimal mode for calculating the water collection end time and obtain the water collection end time correction value.

[0049] In this embodiment, the system determines whether the water flow in the pre-drilled borehole 1 is in a state of pressureless short-time uniform water flow based on the unpressurized short-time uniform water flow model. When it is in a state of pressureless short-time uniform water flow, the measuring cylinder fixture 3 is placed at the point where the water falls. Because the water in the pre-drilled borehole 1 is mineral water with good conductivity, when the water flows to the bottom of the measuring cylinder fixture 3, the sensing control circuit is activated, i.e., the sensing module 303 starts, and the timer begins counting. At this time, the water intake start time can be obtained. When the water in the measuring cylinder fixture 3 reaches the micro float level sensor 302, the micro float level sensor... The miniature float water level sensor 302 emits a sensing signal, the timer stops counting, and the water receiving end time is obtained. In this application, because there are four miniature float water level sensors 302, four different water receiving end times can be obtained. A suitable water receiving end time calculation mode can be selected by adjusting the correction parameter button to calculate the four different water receiving end times. In this embodiment, the calculation modes include arithmetic average mode, average value after removing the minimum value mode, and average value after removing the maximum value mode. The intelligent statistical analysis method used is as follows:

[0050] The four miniature float water level sensors 302 independently measured the water filling end time values, which followed a normal distribution. Their statistical characteristics can be further described by the expected value μ and variance δ, where:

[0051] μ=(t 2-1 +t 2-2 +t 2-3 +t 2-4 ) / 4,

[0052]

[0053] Arithmetic average pattern: If t 2-i -μ is 2 negative and 2 positive, and the arithmetic mean μ is t′2;

[0054] The pattern of removing the minimum value and then taking the average: If t 2-i -μ is 1 negative and 3 positive. The minimum value is removed and the average value is taken as t′2.

[0055] The pattern of removing the maximum value and then taking the average: If t 2-i -μ is 3 negative and 1 positive. The average value after removing the maximum value is t′2.

[0056] S5: Obtain the unpressurized short-time uniform water flow model, decompose the water flow motion of the unpressurized short-time uniform water flow into horizontal uniform deceleration motion with initial velocity V0 and free fall motion with initial velocity 0, and construct a water inlet start time correction algorithm to obtain the water inlet start time correction value.

[0057] Specifically, the algorithm for correcting the water inlet start time in S5 is as follows:

[0058] The short-time uniform flow of unpressurized water can be decomposed into horizontal uniformly decelerated motion with an initial velocity of v0 and free fall motion with an initial velocity of 0.

[0059] Using the formula for the free fall motion of a particle with an initial velocity of 0, H = 1 / 2gt 2 Calculate the time t it takes for the water to fall from the recording point to the bottom of the cylindrical graduated cylinder 301. Then, subtract the free fall time of the water from the recording point to the bottom of the cylindrical graduated cylinder 301 from the water's initial collection time t1 when it falls to the bottom of the cylinder 301. Equal to the precise start time of water intake on cylindrical graduated cylinder 301;

[0060] Construct a water inlet start time correction algorithm:

[0061]

[0062] Where t′1 is the correction value for the water collection start time, t1 represents the water collection start time when the water flows to the bottom of the cylindrical measuring cylinder 301, and H represents the height of the measuring cylinder fixture 3.

[0063] S6: Calculate the water flow rate in the advance borehole 1 based on the water inlet start time correction value, the water inlet end time correction value, and the preset volume of measuring cylinder 3.

[0064] The formula for calculating the water flow rate of the pre-drilled borehole 1 in S6 is as follows:

[0065]

[0066] Among them, t1 ′ t2 is a correction value for the start time of water collection. ′ V represents the volume of the measuring cylinder device 3. In this embodiment, based on the borehole diameter and water flow rate, different measuring cylinders such as 5L, 8L, and 12L and thin-walled weirs with different weir opening areas 202 can be designed. 5L corresponds to e and f in Figure 3, 8L corresponds to d in Figure 3, and 12L corresponds to a, b, and c in Figure 3. f represents the final measured water flow rate result value.

[0067] As shown in Figure 5, in another embodiment of this invention, a device for measuring the flow rate of unpressurized short-time uniform water within the pre-drilled borehole 1 is also included. This device comprises a thin-walled weir diversion device 2, a measuring cylinder fixture 3, and a data processing module. The thin-walled weir diversion device 2 is located at the borehole opening of the pre-drilled borehole 1 and is used to divert the water flowing out of the borehole 1. The measuring cylinder fixture 3 is located at the point where the water falls after being diverted by the thin-walled weir diversion device 2. Multiple miniature float level sensors 302 are evenly arranged around the inner wall of the measuring cylinder fixture 3. When the water flowing out of the pre-drilled borehole 1 is in a state of unpressurized short-time uniform flow, the measuring cylinder fixture 3 activates a sensing control circuit at the center of its bottom region based on the good conductivity of the flowing water to start recording the water intake start time. This application uses a system control board to control... The timer motherboard keeps time and independently records the water receiving end time based on multiple miniature float water level sensors 302; the data processing module is used to acquire the water receiving start time and multiple independently recorded water receiving end times; the data processing module is also used to correct the acquired water receiving start time according to a preset water receiving start time correction algorithm to generate a corrected value for the water receiving start time; the data processing module is also used to process the independently recorded water receiving end times by selecting the optimal mode for calculating the water receiving end time through intelligent statistical analysis to obtain the corrected value for the water receiving end time; the data processing module is also used to calculate the water flow rate result value in the advanced borehole 1 based on the corrected value of the water receiving start time and the corrected value of the water receiving end time, as well as the preset volume of the measuring cylinder device 3.

[0068] The thin-walled weir diversion device 2 includes at least two fastening support rods 201, a thin-walled weir, and a sealing rubber strip. The weir opening 202 of the thin-walled weir is set according to a preset shape. One end of the fastening support rod 201 is fixed to the top of the opening of the pre-drilled hole 1, and the other end is fixed to both sides of the weir opening 202 of the thin-walled weir. The sealing rubber strip is located on the outer edge of the thin-walled weir and seals the opening of the pre-drilled hole 1.

[0069] The measuring cylinder fixture 3 includes a cylindrical measuring cylinder 301, a controller, multiple miniature float level sensors 302, a sensing module 303, and a timer. The miniature float level sensors 302, the sensing module 303, and the timer are all electrically connected to the controller. The sensing module 303 is located at the bottom of the cylindrical measuring cylinder 301. The top of the measuring cylinder has multiple graduation lines, and the miniature float level sensors 302 are located at the graduation lines. The sensing module 303 generates a water-feeding start sensing signal when it senses water at the bottom of the cylindrical measuring cylinder 301. The controller controls the timer to start the water-feeding process based on the water-feeding start sensing signal. Each miniature float level sensor 302 generates a water-feeding end sensing signal when the water level in the cylindrical measuring cylinder 301 reaches a graduation line. The controller controls the timer to stop the timer based on the water-feeding end sensing signal. The controller also transmits the water-feeding start time and water-feeding end time recorded by the timer to the data processing module for water flow calculation.

[0070] In this embodiment, the controller uses a system control board, specifically an STM32 microcontroller. The timer's timing motherboard is connected to the system control board, and the control button 307 uses a correction parameter adjustment button for correction operations.

[0071] The above are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for measuring the flow rate of unpressurized short-time uniform water in advanced boreholes, characterized in that: include: S1: Obtain the borehole data of the advanced borehole, fabricate the thin-walled weir diversion device, and install the thin-walled weir diversion device in the advanced borehole; S2: Determine whether the water flow in the pre-drilled borehole is in a state of pressureless short-time uniform water flow based on the preset unpressurized short-time uniform water flow model; S3: Prefabricate a measuring cylinder fixture, with a sensing control circuit (sensor module, timer, and controller) set at the center of the bottom of the measuring cylinder fixture to start the water receiving time; multiple miniature float level sensors are evenly arranged around the inner wall of the top of the measuring cylinder fixture; S4: When the water flow in the pre-drilled borehole is in a state of pressureless short-time uniform water flow, place the measuring cylinder fixture at the water drop point of the thin-walled weir diversion device to receive water. Based on the good conductivity of the flowing water, activate the sensing control circuit at the center of the bottom of the measuring cylinder fixture to start recording the water receiving start time. Record the water receiving end time independently based on multiple miniature float level sensors, and process the independently recorded water receiving end times using intelligent statistical analysis to select the optimal mode for calculating the water receiving end time, obtaining a correction value for the water receiving end time; S5: Obtain the pressureless short-time uniform water flow model, decomposing the water flow motion of the pressureless short-time uniform water flow into an initial velocity of... The horizontal uniformly decelerated motion and free fall motion are analyzed, and a water inlet start time correction algorithm is constructed to obtain the water inlet start time correction value; S6: Calculate the water flow rate in the pre-drilled hole based on the water inlet start time correction value, the water inlet end time correction value, and the preset volume of the measuring cylinder; The orifice data in S1 includes orifice diameter data and elevation angle data. The thin-walled weir diversion device includes at least two fastening support rods, a thin-walled weir, and a sealing rubber strip. The weir opening of the thin-walled weir is set according to a preset shape. One end of the fastening support rod is fixed to the top of the pre-drilled hole opening, and the other end is fixed to both sides of the thin-walled weir opening. The sealing rubber strip is located at the outer edge of the thin-walled weir and seals the pre-drilled hole opening; The water inlet start time correction algorithm in S5 is specifically constructed as follows: The unpressurized short-time uniform flow can be decomposed into an initial velocity of Horizontal uniformly decelerated motion and free fall with an initial velocity of 0; using the formula for free fall of a particle with an initial velocity of 0. Calculate the free fall time Construct an algorithm to correct the water receiving start time: in, This indicates the precise start time of water intake when corrected to the aforementioned record point. This indicates the start time of water collection when the water flows to the bottom of the cylindrical graduated cylinder, and the time it takes for the water to reach the bottom of the cylindrical graduated cylinder. Subtract the free fall time of the water from the recording point to the bottom of the cylindrical graduated cylinder. This allows us to obtain the precise start time of water collection when the water falls to the upper recording point of the cylindrical graduated cylinder, which is consistent with the defined end time of water collection. ， The height of the indicated cylinder fitting.

2. The method for measuring the flow rate of unpressurized short-time uniform water in an advanced borehole according to claim 1, characterized in that: The pre-set pressureless short-time uniform water flow model in S2 is specifically constructed based on fluid mechanics theory, utilizing the fact that the cross-sectional area of ​​the water passage at the borehole opening is less than 1 / 2 of the borehole cross-sectional area, the absence of fluid jets in the borehole, and the stable water flow state to build a pressureless cylindrical uniform flow model.

3. The method for measuring the flow rate of unpressurized short-time uniform water in an advanced borehole according to claim 2, characterized in that: The S3 measuring cylinder fixture includes a cylindrical measuring cylinder, multiple miniature float level sensors, and a controller, sensing module, and timer in the induction control circuit. The miniature float level sensors, sensing module, and timer are all electrically connected to the controller. The sensing module is located at the bottom of the cylindrical measuring cylinder, and the top of the measuring cylinder has multiple graduation lines. The miniature float level sensors are located at the graduation lines. The sensing module generates a water-feeding start sensing signal when it senses water at the bottom of the cylindrical measuring cylinder. The controller controls the timer to start timing based on the water-feeding start sensing signal. Each miniature float level sensor generates a water-feeding end sensing signal when the water level in the cylindrical measuring cylinder reaches a graduation line. The controller controls the timer to stop timing based on the water-feeding end sensing signal.

4. The method for measuring the flow rate of unpressurized short-time uniform water flow in an advanced borehole according to claim 3, characterized in that: The intelligent statistical analysis in S4 selects the optimal calculation mode for the end time of water collection, including the arithmetic mean mode, the mode of removing the minimum value and then taking the average value mode, and the mode of removing the maximum value and then taking the average value mode.

5. A device for measuring the flow rate of unpressurized short-time uniform water in advanced boreholes, characterized in that: The system includes a thin-walled weir diversion device, a measuring cylinder fixture, and a data processing module. The thin-walled weir diversion device is located at the orifice of the pre-drilled hole to divert the water flowing out of the pre-drilled hole. The measuring cylinder fixture is located at the point where the water falls after being diverted by the thin-walled weir diversion device. Multiple miniature float level sensors are evenly arranged around the inner wall of the measuring cylinder fixture. When the water flowing out of the pre-drilled hole is in a state of pressureless, short-term uniform flow, the measuring cylinder fixture activates a sensing control circuit located at the center of its bottom to start recording the water receiving start time, based on the good conductivity of the flowing water. This circuit includes a sensing module, a timer, and a controller. The system also independently records the water receiving end time based on the multiple miniature float level sensors. The data processing module is used to acquire the water receiving start time and the multiple independently recorded water receiving end times. The data processing module is also used to process the acquired water receiving start time according to a preset water receiving start time correction algorithm. The data processing module is used to generate a correction value for the water receiving start time by performing a correction. It also uses intelligent statistical analysis to select the optimal calculation mode for the water receiving end time and processes the independently recorded water receiving end time to obtain a correction value. Furthermore, the data processing module calculates the water flow rate in the pre-drilled borehole based on the correction values ​​for the water receiving start time and end time, as well as the preset volume of the measuring cylinder. The thin-walled weir diversion device includes at least two fastening support rods, a thin-walled weir, and a sealing rubber strip. The weir opening of the thin-walled weir is set according to a preset shape. One end of each fastening support rod is fixed to the top of the pre-drilled borehole opening, and the other end is fixed to both sides of the thin-walled weir opening. The sealing rubber strip is located at the outer edge of the thin-walled weir and seals against the inner wall at the pre-drilled borehole opening. The water receiving start time correction algorithm is as follows: the unpressurized short-time uniform flow can be decomposed into an initial velocity of... Horizontal uniformly decelerated motion and free fall with an initial velocity of 0; using the formula for free fall of a particle with an initial velocity of 0. Calculate the free fall time Construct an algorithm to correct the water receiving start time: in, This indicates the precise start time of water intake when corrected to the aforementioned record point. This indicates the start time of water collection when the water flows to the bottom of the cylindrical graduated cylinder, and the time it takes for the water to reach the bottom of the cylindrical graduated cylinder. Subtract the free fall time of the water from the recording point to the bottom of the cylindrical graduated cylinder. This allows us to obtain the precise start time of water collection when the water falls to the upper recording point of the cylindrical graduated cylinder, which is consistent with the defined end time of water collection. ， The height of the indicated cylinder fitting.

6. The device for measuring the flow rate of unpressurized short-time uniform water in an advanced borehole according to claim 5, characterized in that: The graduated cylinder apparatus includes a cylindrical graduated cylinder, multiple miniature float level sensors, and a controller, sensing module, and timer in the inductive control circuit. The miniature float level sensors, sensing module, and timer are all electrically connected to the controller. The sensing module is located at the bottom of the cylindrical graduated cylinder, and the top of the graduated cylinder has multiple graduation lines. The miniature float level sensors are located at the graduation lines on the inner wall of the top of the cylindrical graduated cylinder. The sensing module generates a water-feeding start sensing signal when it senses water at the bottom of the cylindrical graduated cylinder. The controller controls the timer to start the water-feeding process based on the water-feeding start sensing signal. Each miniature float level sensor generates a water-feeding end sensing signal when the water level in the cylindrical graduated cylinder reaches a graduation line. The controller controls the timer to stop the water-feeding process based on the water-feeding end sensing signal. The controller also transmits the water-feeding start time and water-feeding end time recorded by the timer to the data processing module for water flow calculation.

Images