Methods and apparatus for detecting liquid leakage sources

Abstract

This application provides a method and apparatus for detecting liquid leakage sources. It involves acquiring geographic information data and on-site survey data of the object to be investigated; establishing a geographic information model based on the geographic information data and on-site survey data; implementing detection based on the geographic information model and preset operating conditions; after a set operating cycle, acquiring monitoring data from a tracer detection device installed in a downstream groundwater monitoring well; outputting the leakage result of the investigated object based on the monitoring data; and detecting the signal and concentration of tracers in the groundwater at the downstream target location. This allows for a preliminary assessment of the connectivity between the investigated target and groundwater, and an evaluation of the potential pollution level of the leaking substances at the investigation point on the groundwater. It addresses problems such as the concealment of soil and groundwater pollution sources in operating enterprises, unclear migration and diffusion channels for leaked contaminated soil and groundwater, and difficulty in simulating and characterizing the leakage pollution process.

Description

Technical Field

[0001] This application relates to the field of soil and groundwater pollution source investigation technology in industrial and mining enterprises, specifically to a method and device for detecting liquid leakage sources. Background Technology

[0002] The first national soil pollution survey bulletin released in 2014 showed that the exceedance rates of soil pollution in heavily polluted enterprise land, industrial waste sites, and industrial parks were 36.3%, 34.9%, and 29.4%, respectively, indicating a high risk of soil and groundwater pollution from industrial and mining enterprises. The "Action Plan for Soil Pollution Source Prevention and Control," released in 2024, clearly states that by 2027, significant results will be achieved in soil pollution source prevention and control, with the compliance rate of hazard investigation and rectification at key soil pollution monitoring units reaching over 90%. By 2030, all indicators will be further improved. In the coming years, conducting source investigations of soil and groundwater seepage pollution will be the most important environmental protection task for all operating industrial and mining enterprises, creating a significant demand for seepage investigation technologies.

[0003] Existing source tracing investigation methods suffer from barriers to data sharing and integration, resulting in individual problems being solved separately and solutions having low reusability. Summary of the Invention

[0004] To address this, this application provides a method and apparatus for detecting liquid leakage sources, thereby solving the problems of existing source tracing investigation methods, such as data sharing and integration barriers, individual problem-solving, and low reusability of solutions.

[0005] A first aspect of this application provides a method for detecting liquid leakage sources, comprising: Obtain geographic information data and on-site survey data of the objects to be investigated; A geographic information model is established based on geographic information data and field survey data; Based on the geographic information model, detection is performed according to preset operating conditions; After running for a set period, acquire monitoring data from the tracer detection equipment installed in the downstream groundwater monitoring well; The leakage results of the investigated objects are output based on the monitoring data.

[0006] Furthermore, in the above-described method, obtaining the geographic information data and on-site survey data of the object to be investigated includes: Obtain land use information, site information, and existing groundwater monitoring well information of the object to be investigated; obtain groundwater flow velocity and direction; obtain groundwater aquifer porosity, aquifer thickness, water storage coefficient, and water conductivity coefficient of the site; obtain the water storage volume and water supply and drainage cycle of the liquid storage facilities of the object to be investigated.

[0007] Furthermore, in the above-described method, the step of establishing a geographic information model based on geographic information data and on-site survey data includes: constructing a three-dimensional geographic model based on the land use information, site information, and existing groundwater monitoring well information of the object to be investigated; assigning parameter values ​​to the geographic element components of the three-dimensional geographic model based on the porosity, thickness, storage coefficient, and permeability coefficient of the groundwater aquifer at the site; and assigning parameter values ​​to the target elements of the three-dimensional geographic model based on the water storage volume and drainage cycle of the liquid storage facility of the object to be investigated, thereby obtaining a geographic information model.

[0008] Furthermore, in the above-described method, the step of performing detection based on the geographic information model according to preset operating conditions includes: For liquid storage facilities within the geographic information model, investigation points are determined according to the leakage risk level and liquid transport relationship; Based on the distribution of investigation points and existing groundwater monitoring wells in the geographic information model, and combined with the groundwater flow direction relationship, investigation combinations are allocated according to the relationship between investigation points and groundwater monitoring wells. The relationship between investigation points and groundwater monitoring wells represents the relationship between the tracer dosing point and the downstream tracer signal receiving point. The amount and frequency of tracer addition are calculated based on the liquid storage capacity and renewal cycle of the liquid storage facilities at the investigation points, as well as the distance between the existing groundwater monitoring wells and the investigation points.

[0009] Furthermore, in the method described above, the dosage of the tracer is calculated using the following formula: In the formula: (1) M represents the amount of tracer added, in kg; (2) N represents the detection limit of the tracer detection equipment, which can be taken as 1×10 -9 Or 1×10 -10 (Unit: kg / m³) 3 (3) R represents the distance between the investigation point and the monitoring well, in meters; (4) H represents the thickness of the groundwater aquifer, in meters; (5) μ represents the porosity of the groundwater aquifer, in percentages; (6) Guarantee coefficient , which represents the possible leakage rate after a single tracer injection.

[0010] Furthermore, in the above-described method, the step of performing detection based on the geographic information model according to preset operating conditions includes selecting one or more tracers based on the identification capabilities and screening requirements of existing fluorescent tracer detection equipment, and determining the category of the tracer.

[0011] Furthermore, in the above-described method, after the set operating period, acquiring the monitoring data of the tracer detection device installed in the downstream groundwater monitoring well includes: based on the operating conditions, installing the tracer detection device in the downstream groundwater monitoring well; acquiring the background value monitored by the tracer detection device; adding tracer to the upstream investigation point; and acquiring the monitoring data obtained by the tracer detection device at a preset frequency.

[0012] Furthermore, in the method described above, the step of outputting the leakage result of the investigated object based on the monitoring data includes: performing concentration conversion on the monitoring data and simulating the leakage rate; determining the maximum allowable value of the facility's leakage rate based on at least one of the type, structure, and material of the investigated object, and comparing and evaluating the degree of leakage of the investigated object.

[0013] Furthermore, in the methods described above, when the difference in tracer capture concentration in groundwater before and after tracer addition does not exceed three times, the leakage rate of the liquid storage facility is calculated using the following formula: In the formula: (1) (1) V represents the leakage rate of the liquid storage facility, in units of %; (2) V represents the liquid storage capacity of the liquid storage facility, in conventional units of m³. 3 (3) C is the average value of the concentration curve captured by the tracer signal detection equipment in the groundwater monitoring well, minus the original cost value (unit: ppb, 1×10). -9 kg / m 3 (4) K represents the volume correction factor (less than 1), which can be corrected according to the groundwater flow rate. When assessing the maximum possible leakage rate of the investigated object, the coefficient is 1; (5) R represents the distance between the investigation point and the monitoring well, in m; (6) H represents the thickness of the groundwater aquifer, in m; (7) μ represents the porosity of the groundwater aquifer, in %; (8) M represents the amount of tracer added, in kg; When the concentration difference of the tracer in groundwater before and after tracer addition is greater than 3 times, the leakage rate of the investigated object is calculated using the following formula: In the formula: (1) (1) μ represents the leakage rate of the investigated object, in units of %; (2) μ represents the porosity of the groundwater aquifer, in units of %; (3) A is the receiving cross-sectional area of ​​the tracer groundwater monitoring well, in units of m². 2 (4) V represents the pore flow velocity of groundwater, unit: m / d; (5) C(t) represents the instantaneous concentration of the tracer in the monitoring well. The tracer capture mass is calculated by integrating the concentration curve, unit: kg; (6) M represents the amount of tracer added, unit: kg.

[0014] A second aspect of this application provides a liquid leakage source detection device, comprising: The data acquisition module is used to acquire geographic information data and on-site survey data of the objects to be investigated; The modeling module is used to build geographic information models based on geographic information data and field survey data. The detection module is used to perform detection based on the geographic information model according to preset operating conditions; The monitoring data acquisition module is used to acquire monitoring data from the tracer detection equipment installed in the downstream groundwater monitoring well after a set operating cycle. The result output module is used to output the leakage results of the investigated object based on the monitoring data.

[0015] This application provides a method for detecting liquid leakage sources. The method involves acquiring geographic information data and on-site survey data of the target object; establishing a geographic information model based on the geographic information data and on-site survey data; implementing detection based on the geographic information model under preset operating conditions; after a set operating cycle, acquiring monitoring data from a tracer detection device installed in a downstream groundwater monitoring well; outputting leakage results of the target object based on the monitoring data; and detecting the signal and concentration of tracers in the groundwater at the downstream target location. This allows for a preliminary assessment of the connectivity between the target object and groundwater, and an evaluation of the potential pollution level of the leaking substances at the investigation point. This method addresses problems such as the concealment of soil and groundwater pollution sources in operating enterprises, unclear migration and diffusion channels for leaked contaminated soil and groundwater, and difficulty in simulating and characterizing the leakage pollution process. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 A schematic flowchart illustrating the liquid leakage source detection method provided in this application embodiment; Figure 2 A schematic diagram of the geographic information model provided in the embodiments of this application; Figure 3 This is a schematic diagram of the tracer distribution scheme in a specific embodiment of this application; Figure 4 This is the tracer capture monitoring curve before modification in a specific embodiment of this application; Figure 5 This is a modified tracer capture monitoring curve in a specific embodiment of this application; Figure 6A schematic diagram of a liquid leakage source detection device is provided for another embodiment of this application; Figure 7 This is a schematic diagram of the structure of an electronic device shown in an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] Fluorescent materials possess the property of emitting fluorescence upon excitation by light of a specific wavelength. Specialized equipment allows for the production of ultra-micro quantities (dilution factors up to 1×10⁻⁶). 12 The identification methods include (level), high frequency (measurement every 2 seconds to 2 minutes), and automation (automatic storage of large amounts of data). Fluorescent tracer technology involves introducing tracers at the source or upstream investigation point of groundwater, and detecting the signal and concentration of the tracers in the groundwater at the downstream target location. This allows for a preliminary assessment of the connectivity between the investigation target and groundwater, and an evaluation of the potential pollution level of the groundwater caused by leaked substances at the investigation point. It can solve problems such as the concealment of soil and groundwater pollution sources in operating enterprises, unclear migration and diffusion channels of leaked contaminated soil and groundwater, and difficulty in simulating and characterizing the leakage pollution process.

[0020] This application's embodiments utilize fluorescent tracer technology to conduct a liquid leakage source detection method; see [link to relevant documentation]. Figure 1 ,include: S1: Obtain geographic information data and on-site survey data of the object to be investigated; S2: Establish a geographic information model based on geographic information data and field survey data; S3: Detection is performed based on the geographic information model according to preset operating conditions; S4: After running the set cycle, acquire the monitoring data of the tracer detection equipment installed in the downstream groundwater monitoring well; S5: Output the leakage results of the investigated object based on the monitoring data.

[0021] In one embodiment provided in this application, step S1: obtaining geographic information data and on-site survey data of the object to be investigated, including: Obtain land use information, site information, and existing groundwater monitoring well information of the object to be investigated; obtain groundwater flow velocity and direction; obtain groundwater aquifer porosity, aquifer thickness, water storage coefficient, and water conductivity coefficient of the site; obtain the water storage volume and water supply and drainage cycle of the liquid storage facilities of the object to be investigated.

[0022] Specifically, the geographic information data of the objects to be investigated is obtained, including: ① obtaining land use information of the objects to be investigated, including hydrogeological maps and hydrogeological data; ② obtaining site information of the objects to be investigated, including the structural form, seepage prevention performance, and daily data on liquid storage and discharge of various pools, pits and liquid storage tanks; ③ obtaining information on existing groundwater monitoring wells, including groundwater well depth, groundwater output, and water level monitoring data.

[0023] Specifically, the on-site survey data of the objects to be investigated includes: ① using water level gauges to test the water levels of different groundwater monitoring wells to preliminarily determine the groundwater flow direction, and verifying this with online groundwater velocity and direction meters to accurately grasp the groundwater flow velocity and direction at the site; ② conducting on-site pumping experiments, using existing groundwater monitoring wells at the site to test the porosity of the site and the thickness of the aquifer, water storage coefficient, and permeability coefficient of the groundwater; ③ obtaining the water volume and drainage cycle of suspected leakage points such as liquid storage facilities.

[0024] In one embodiment provided in this application, step S2: establishing a geographic information model based on geographic information data and on-site survey data includes: constructing a three-dimensional geographic model based on the land use information, site information, and existing groundwater monitoring well information of the object to be investigated; assigning parameter values ​​to the geographic element components of the three-dimensional geographic model based on the porosity, thickness, storage coefficient, and permeability coefficient of the groundwater aquifer at the site; and assigning parameter values ​​to the target elements of the three-dimensional geographic model based on the water storage volume and drainage cycle of the liquid storage facility of the object to be investigated, thereby obtaining a geographic information model.

[0025] See Figure 2 The geographic information model shown includes: 1. Underground aquifer in the plant area; 2. Underground vadose zone in the plant area; 3. Buried liquid storage facilities; 4. Surface buildings and structures; 5. Surface liquid storage facilities; 6. Plant surface; 7. Tracer signal monitoring equipment; and 8. Groundwater monitoring wells. Arrows represent the direction of groundwater flow. Liquid storage facilities may include tanks, pits, etc.

[0026] In one embodiment provided in this application, step S3: the detection based on the geographic information model according to preset operating conditions includes, S301, for the liquid storage facilities within the geographic information model, determine the investigation points according to the leakage risk level and liquid transport relationship; suspected leakage points usually include various pools, pits and storage tanks and other liquid storage facilities. S302, based on the distribution of investigation points in the geographic information model and the distribution of existing groundwater monitoring wells, and combined with the groundwater flow direction relationship, the investigation combination is allocated according to the relationship between investigation points and groundwater monitoring wells. The relationship between investigation points and groundwater monitoring wells represents the relationship between the tracer dosing point and the downstream tracer signal receiving point. S303, calculate the amount of tracer to be added based on the liquid storage capacity and renewal cycle of the liquid storage facility at the investigation point, as well as the distance between the existing groundwater monitoring well and the investigation point. In this step, the tracer concentration requirements under special circumstances can also be further considered, such as the tracer concentration requirement for microorganisms in the downstream biological treatment tank of the sewage treatment plant being within a suitable range, and the tracer concentration not being too high for the visual effect of rainwater sedimentation tank discharge.

[0027] In one embodiment provided in this application, the dosage of the tracer is calculated using the following formula: In the formula: (1) M represents the amount of tracer added, in kg; (2) N represents the detection limit of the tracer detection equipment, which can be taken as 1×10 -9 Or 1×10 -10 (Unit: kg / m³) 3 (3) R represents the distance between the investigation point and the monitoring well, in meters; (4) H represents the thickness of the groundwater aquifer, in meters; (5) μ represents the porosity of the groundwater aquifer, in percentages; (6) Guarantee coefficient , which represents the possible leakage rate after a single tracer injection.

[0028] In one embodiment provided in this application, the detection based on the geographic information model according to preset operating conditions includes selecting one or more tracers and determining the category of the tracer based on the identification capabilities and screening requirements of existing fluorescent tracer detection equipment. For example, a fluorescent tracer detection device can identify three types of fluorophores, but data correction is required when there is signal interference between them.

[0029] In one embodiment provided in this application, step S4: after the set operation period, acquiring monitoring data of the tracer detection device installed in the downstream groundwater monitoring well includes: based on the operating conditions, installing the tracer detection device in the downstream groundwater monitoring well; acquiring the background value monitored by the tracer detection device; adding tracer to the upstream investigation point; and acquiring the monitoring data obtained by the tracer detection device at a preset frequency.

[0030] Specifically, tracer detection equipment is installed in the downstream groundwater monitoring well. Before adding the tracer, the background value is monitored for a period of time. Tracer is added to the investigation point, an appropriate monitoring frequency is set, and the strength of the tracer-captured signal is observed. The need for continued monitoring is assessed based on the changing patterns; for example, monitoring can be terminated when the trend of the tracer-captured signal strength becomes relatively flat. Furthermore, during the monitoring period, changes in the groundwater flow direction at the site are simultaneously tested using a water level gauge or groundwater velocity and direction meter. If the flow direction changes, the process can return to step S302, and the monitoring well can be replaced according to the new pairing relationship.

[0031] In one embodiment provided in this application, step S5: outputting the leakage result of the investigated object based on the monitoring data includes: performing concentration conversion on the monitoring data and simulating the leakage rate; determining the maximum allowable value of the facility's leakage rate based on at least one of the type, structure, and material of the investigated object, and comparing and evaluating the degree of leakage of the investigated object.

[0032] In one embodiment provided in this application, the process of leakage diffusion from the target groundwater well to the monitoring groundwater well can be preliminarily determined based on the tracer capture curve of the groundwater well. ② The concentration of the tracer capture signal is converted, and combined with the tracer dosage concentration and the hydrogeological parameters of the site, the leakage rate can be simulated and calculated. ③ Based on the type, structure, or material of the target, the maximum allowable leakage value for the facility according to relevant standards is found, and the degree of leakage of the target is compared and evaluated.

[0033] Specifically, the leakage rate of liquid storage facilities is calculated as follows: When the difference in tracer capture concentration in groundwater before and after tracer addition does not exceed three times, the leakage rate of the liquid storage facility shall be calculated using the following formula: In the formula: (1) (1) V represents the leakage rate of the liquid storage facility, in units of %; (2) V represents the liquid storage capacity of the liquid storage facility, in conventional units of m³. 3 (3) C is the average value of the concentration curve captured by the tracer signal detection equipment in the groundwater monitoring well, minus the original cost value (unit: ppb, 1×10). -9 kg / m 3 (4) K represents the volume correction factor (less than 1), which can be corrected according to the groundwater flow rate. When assessing the maximum possible leakage rate of the investigated object, the coefficient is 1; (5) R represents the distance between the investigation point and the monitoring well, in m; (6) H represents the thickness of the groundwater aquifer, in m; (7) μ represents the porosity of the groundwater aquifer, in %; (8) M represents the amount of tracer added, in kg; When the concentration difference of the tracer in groundwater before and after tracer addition is greater than 3 times, the leakage rate of the investigated object is calculated using the following formula: In the formula: (1) (1) μ represents the leakage rate of the investigated object, in units of %; (2) μ represents the porosity of the groundwater aquifer, in units of %; (3) A is the receiving cross-sectional area of ​​the tracer groundwater monitoring well, in units of m². 2 (4) V represents the pore flow velocity of groundwater, unit: m / d; (5) C(t) represents the instantaneous concentration of the tracer in the monitoring well. The tracer capture mass is calculated by integrating the concentration curve, unit: kg; (6) M represents the amount of tracer added, unit: kg.

[0034] The technical solution of this application will be further explained below with reference to specific embodiments.

[0035] (1) Obtaining geographic information data and on-site survey data of the target: A certain enterprise in production, geographic information data and on-site survey data show that it is located in a volcanic rock area, with a backfill area composed of a large amount of gravel, boulders and rock fragments on top. The main factory buildings are located on exposed volcanic bedrock. The groundwater can be divided into two categories: Quaternary pore water and bedrock fissure water. The hydrogeological conditions are simple and the permeability is relatively weak. There are a total of 9 pools or pits that may leak and cause pollution to the soil and groundwater, which are the targets to be investigated. The materials are mostly concrete structures. There are 5 groundwater monitoring wells available in the factory area. The well depth is 20-25 meters and the water level is generally 7-10 meters below the ground. The water level of the 5 groundwater monitoring wells on the site was tested. The groundwater flow direction and velocity were determined by combining the flow velocity and direction instrument test. According to the previous pumping test, the porosity of the aquifer on the site was determined to be 0.12.

[0036] (2) Establish a geographic information model based on geographic information data and field survey data: Generate a three-dimensional geographic model from the land use information, site information and existing groundwater monitoring well information obtained above. Specifically, a basic model can be constructed based on the survey dimensions using three-dimensional drawing software, and attribute values ​​can be assigned in combination with land use information. Groundwater monitoring wells can be added at the corresponding locations. Parameter values ​​can be assigned to the geographic element components of the three-dimensional geographic model based on the porosity and thickness of the groundwater aquifer, water storage coefficient and permeability coefficient of the site. Parameter values ​​can also be assigned to the target elements of the three-dimensional geographic model based on the water storage volume and drainage cycle of the liquid storage facilities of the object to be investigated, thus obtaining a geographic information model.

[0037] (3) Based on the geographic information model, perform detection according to preset operating conditions: The liquid storage facilities within the geographic information model were numbered, and nine pits requiring leakage investigation were identified. These nine pits were determined according to their hydraulic connection and water supply / drainage relationship, see [reference needed]. Figure 3Target No. 1 enters the dedicated wastewater treatment system, targets No. 2-5 flow into the municipal drainage system respectively, and targets No. 6-8 flow into target No. 9 (oil-water separator) respectively. According to the leakage risk level and liquid transport relationship, the targets directly connected to the drainage system are designated as the investigation points, that is, the investigation points are No. 1, 2-5, and No. 9.

[0038] Based on the distribution of investigation points and existing groundwater monitoring wells within the geographic information model, and combined with the groundwater flow direction, investigation combinations are allocated according to the relationship between investigation points and groundwater monitoring wells. The relationship between investigation points and groundwater monitoring wells represents the relationship between the tracer dosing point and the downstream tracer signal receiving point. Assuming that based on the distribution of investigation points 1-9 and the existing 5 groundwater monitoring wells, three groundwater monitoring wells A, B, and C are located downstream of investigation point 1, investigation points 2-5, and investigation point 9, respectively, the relationship between investigation points and groundwater monitoring wells is obtained as 1-A, 2-B, 3-B, 4-B, 5-B, and 9-C.

[0039] The amount of tracer to be added is calculated based on the liquid storage capacity and renewal cycle of the liquid storage facility at the investigation point, as well as the distance between the existing groundwater monitoring well and the investigation point.

[0040] Based on the above-mentioned distribution, the concentrations of three tracers were continuously monitored in groundwater wells A, B, and C approximately 20 meters downstream, with automatic testing and recording every 30 seconds (equipment automation). Given that the pits are made of reinforced concrete, the "Technical Guidelines for Seepage Prevention of Groundwater Pollution Sources" stipulates a leakage limit of no more than 0.2 L / (d·m²) for this type of pit. Based on this, the maximum allowable leakage value for each pit was calculated. Then, the tracer concentration in the monitoring wells 20 meters downstream was determined to be no less than 10... -10 For g / L calculation, taking the No. 9 inspection object as an example (concrete pit, 2.5 meters long, 1.6 meters wide, and 1.5 meters high), the water in the pit is changed every 3 days.

[0041] Guarantee factor for potential leakage rate after a single tracer injection: k=V 允漏 / V 总 ×100%=[L*W+2(L+W)*H]*q*T / 1000*L*W*H×100% In the formula, (1) V 允漏 (2) V represents the maximum permissible leakage volume in L; 总 (3) L represents the total volume of water in the pit, in units of L; (4) W represents the width of the pit, in units of m; (5) H represents the height of the pit, in units of m; (6) q represents the allowable surface leakage, in units of L / (d·m²); (7) T represents the water replacement cycle, in units of d (days). According to the above formula, in this embodiment, =[2.5×1.6+(2.5+1.6)×2×1.5)]×0.2×3 / (2.5×1.6×1.5×1000)=0.163%; Therefore, the tracer dosage for the pit at investigation point No. 9 is: =10 -10 ×Π×20×20×10×0.12 / 0.163%=0.0092kg=9.2g (4) Based on the operating conditions, a tracer detection device is installed in the downstream groundwater monitoring well; the background value monitored by the tracer detection device is obtained; tracer is added to the upstream investigation point, and the monitoring data obtained by the tracer detection device at a preset frequency is obtained: After the leakage investigation of this operating enterprise is launched, the background values ​​of three different fluorescent tracers are first monitored in the downstream groundwater monitoring well. One week later, tracers are added according to the above method. Fluorescent whitening agent is added to investigation point 1, Rhodamine B is added to investigation points 2-5, and sodium fluorescein is added to investigation point 9. After about one and a half days, the concentration of tracer begins to rise significantly, reaches its peak on the 5th day, and begins to decline after one day. On the 6th day, tracer is added again, reaches its peak again after about one day, and begins to decline. Monitoring continues for another week. During this period, groundwater level, flow direction, and flow velocity were continuously monitored to determine whether the groundwater monitoring wells used for tracer capture were downstream of the leakage investigation point. The tracer capture curves in the downstream groundwater monitoring wells used in this leakage investigation are shown below. Figure 4 The horizontal axis represents time, with a minimum step size of 12 hours.

[0042] In one embodiment provided in this application, the method further includes the identification of true and false leakage sources by means of the relative concentrations of various tracers captured. For example, signal 1 corresponds to sodium fluorescein, which is only added to pit 9 (oil-water separation tank). The fluorescence wavelengths emitted by the tracer capture device in monitoring well C include 520nm, 438nm, and 580nm. The fluorescence at 520nm wavelength is captured and identified by the sodium fluorescein receiver, while the fluorescence at 438nm and 580nm is incorrectly identified by the fluorescent whitening agent and rhodamine receivers, thus creating the illusion of changes in the detection concentrations of fluorescent whitening agent and rhodamine, as shown in curves 2 and 3 respectively. Therefore, the capture curves of these two tracers need to be corrected. Based on empirical values, according to "ΔC..." 罗丹明B =0.507C 荧光素钠 ΔC 荧光增白剂 =0.507C 荧光素钠 The interference concentration is subtracted to obtain a new curve as shown below. Figure 5 As shown, the horizontal axis represents time, and the minimum step size is 12 hours.

[0043] In the above embodiments, if the points represented by the fluorescent whitening agent and rhodamine are genuine leaks, the concentration changes of the fluorescent whitening agent and rhodamine should be strongly correlated with their own addition conditions (such as addition time and dosage), and should not have a fixed multiple relationship with the concentration changes of sodium fluorescein. For example, if only sodium fluorescein is added and the latter two are not added, theoretically the concentrations of the latter two should remain at the background value and will not fluctuate with the concentration of sodium fluorescein; if the latter two are added, the peak concentration time and trend of their changes should also be independent of sodium fluorescein. However, the equipment misidentifies the 520nm fluorescence of sodium fluorescein (partial wavelength drift or equipment cross-response) as 438nm and 580nm, causing the "false concentrations" of the latter two to form a synchronous fluctuation and a fixed ratio (0.507 times ratio in the embodiment, which is essentially the cross-response coefficient of the equipment to 520nm fluorescence). This conforms to the rule that "interference signals change with target signals", rather than the "independent signals" of genuine leaks. Therefore, it is determined to be an incorrect identification.

[0044] (5) Perform concentration conversion on the monitoring data and simulate the leakage rate; determine the maximum allowable leakage rate of the facility based on at least one of the type, structure, and material of the object under investigation, and compare and evaluate the leakage degree of the object under investigation. In the above experiment, the curves 2 and 3 in monitoring well C before and after the addition of the tracer did not change much. Therefore, except for pit No. 9, there was basically no leakage. The leakage rate was lower than the standard of no more than 0.2 L / (d·m²) in the "Technical Guidelines for Seepage Prevention of Groundwater Pollution Sources". According to the specific size of each pit, it was basically lower than 0.2%.

[0045] Taking the leakage rate of Pit No. 9 as an example, its type is first determined to be a pit. A 24-hour concentration of 170 ppb is selected for calculation. The receiving cross-sectional area of ​​the tracer groundwater monitoring well is calculated based on a groundwater radial flow diffusion angle of 30° (taken as 1500m²). 2 The groundwater pore flow velocity is calculated based on the empirical permeability coefficient of fine sand (1-5 m / d) and the tracer capture curve, with 5 m / d chosen for calculation. Since the difference in tracer capture concentration in groundwater before and after tracer addition is greater than 3 times, the following formula is used for calculation: =0.12×1500×3×170×10 -9 / (9.2×10 -3 )=1.0% Calculations show that the leakage rate of pit No. 9 is approximately 1.0%, exceeding the 0.163% limit stipulated in the "Technical Guidelines for Seepage Prevention of Groundwater Pollution Sources" for pit size, which specifies a leakage rate not exceeding 0.2 L / (d·m²). This exceeds the allowable value by approximately 6.1 times. Therefore, pit No. 9 is suspected of significant leakage, and the leakage source is identified as pit No. 9.

[0046] Another embodiment of this application provides a liquid leakage source detection device, see [link to relevant documentation]. Figure 6 ,include: The data acquisition module 601 is used to acquire geographic information data and on-site survey data of the object to be investigated. Modeling module 602 is used to build geographic information models based on geographic information data and field survey data; Detection module 603 is used to perform detection based on the geographic information model according to preset operating conditions; The monitoring data acquisition module 604 is used to acquire monitoring data of the tracer detection equipment installed in the downstream groundwater monitoring well after a set running cycle; The result output module 605 is used to output the leakage results of the investigated object based on the monitoring data.

[0047] Figure 7 This is a schematic diagram of the structure of an electronic device shown in an embodiment of this application.

[0048] See Figure 7 The electronic device includes a memory 701 and a processor 702.

[0049] The electronic device includes a memory 701 and a processor 702; The memory 701 is connected to the processor 702 and is used to store programs; Processor 702 is used to implement some or all of the methods described above by running programs stored in memory 701.

[0050] Specifically, the aforementioned electronic device may further include: a bus, a communication interface 703, an input device 704, and an output device 705.

[0051] The processor 702, memory 701, communication interface 703, input device 704, and output device 705 are interconnected via a bus. Among them: A bus can include a pathway for transmitting information between various components of a computer system.

[0052] The processor 702 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0053] Processor 702 may include a main processor, as well as a baseband chip, modem, etc.

[0054] Memory 701 may include various types of storage units, such as system memory, read-only memory (ROM), and permanent storage devices. ROM may store static data or instructions required by processor 702 or other modules of the computer. Permanent storage devices may be read-write storage devices. Permanent storage devices may be non-volatile storage devices that retain stored instructions and data even when the computer is powered off. In some embodiments, permanent storage devices use mass storage devices (e.g., magnetic or optical disks, flash memory) as permanent storage devices. In other embodiments, permanent storage devices may be removable storage devices (e.g., floppy disks, optical drives). System memory may be a read-write storage device or a volatile read-write storage device, such as dynamic random access memory. System memory may store some or all of the instructions and data required by the processor during operation. Furthermore, memory 701 may include any combination of computer-readable storage media, including various types of semiconductor memory chips (e.g., DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and disks and / or optical disks may also be used. In some embodiments, memory 701 may include a removable storage device that is readable and / or writable, such as a laser disc (CD), a read-only digital multifunction optical disc (e.g., DVD-ROM, dual-layer DVD-ROM), a read-only Blu-ray disc, an ultra-high density optical disc, a flash memory card (e.g., SD card, mini SD card, Micro-SD card, etc.), a magnetic floppy disk, etc. Computer-readable storage media do not contain carrier waves or transient electronic signals transmitted wirelessly or via wired connections.

[0055] Input device 704 may include a device for receiving data and information input by a user, such as a keyboard, mouse, camera, scanner, light pen, voice input device, touch screen, pedometer, or gravity sensor.

[0056] Output device 705 may include devices that allow information to be output to a user, such as a display screen, printer, speaker, etc.

[0057] The communication interface 703 may include a device that uses any transceiver to communicate with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), Wireless Local Area Network (WLAN), etc.

[0058] The processor 702 executes the program stored in the memory 701 and calls other devices, and can be used to implement some or all of the methods described above.

[0059] Furthermore, the method according to this application can also be implemented as a computer program product, which includes computer program code instructions for performing some or all of the steps in the method described above. Optionally, the computer program can be stored on a readable storage medium of a computer device or in the cloud; the processor of the computer device reads the computer program from the readable storage medium or the cloud.

[0060] Computer program products can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0061] The aforementioned computer program product can be implemented through hardware, software, or a combination thereof. In one optional embodiment, the computer program product is specifically embodied in a computer storage medium; in another optional embodiment, the computer program product is specifically embodied in a software product, such as a software development kit (SDK), etc.

[0062] Alternatively, this application may be implemented as a computer-readable storage medium (or a non-transitory machine-readable storage medium or a machine-readable storage medium) storing executable code (or computer program or computer instruction code) that, when executed by a processor of an electronic device (or server, etc.), causes the processor to perform part or all of the steps of the methods described above according to this application.

[0063] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may, for example, include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0064] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for detecting liquid leakage sources, characterized in that, include: Obtain geographic information data and on-site survey data of the objects to be investigated; The acquisition of geographic information data and on-site survey data of the object to be investigated includes: acquiring land use information, site information, and existing groundwater monitoring well information of the object to be investigated; acquiring groundwater flow velocity and direction; acquiring groundwater aquifer porosity, aquifer thickness, water storage coefficient, and water conductivity coefficient of the site; and acquiring the water storage volume and water supply and drainage cycle of the liquid storage facilities of the object to be investigated. A geographic information model is established based on geographic information data and field survey data. This process includes: constructing a three-dimensional geographic model based on the land use information, site information, and existing groundwater monitoring well information of the object to be investigated; assigning parameter values ​​to the geographic element components of the three-dimensional geographic model based on the porosity, thickness, storage coefficient, and permeability coefficient of the groundwater aquifer at the site; and assigning parameter values ​​to the target elements of the three-dimensional geographic model based on the water storage volume and drainage cycle of the liquid storage facilities of the object to be investigated, thereby obtaining the geographic information model. The detection is carried out based on the geographic information model and preset operating conditions; the detection based on the geographic information model and preset operating conditions includes determining the inspection points for liquid storage facilities within the geographic information model according to the leakage risk level and liquid transport relationship; Based on the distribution of investigation points and existing groundwater monitoring wells in the geographic information model, and combined with the groundwater flow direction relationship, investigation combinations are allocated according to the relationship between investigation points and groundwater monitoring wells. The relationship between investigation points and groundwater monitoring wells represents the relationship between the tracer dosing point and the downstream tracer signal receiving point. Based on the liquid storage capacity and renewal cycle of the liquid storage facilities at the investigation points, as well as the distance between the existing groundwater monitoring wells and the investigation points, the dosage and frequency of the tracer are calculated. After running for a set period, acquire monitoring data from the tracer detection equipment installed in the downstream groundwater monitoring well; The leakage results of the investigated objects are output based on the monitoring data.

2. The liquid leakage source detection method according to claim 1, characterized in that, The dosage of the tracer is calculated using the following formula: In the formula: (1) M represents the amount of tracer added, in kg; (2) N represents the detection limit of the tracer detection equipment, taken as 1×10 -9 Or 1×10 -10 Unit: kg / m 3 (3) R represents the distance between the investigation point and the monitoring well, in meters; (4) H represents the thickness of the groundwater aquifer, in meters; (5) μ represents the porosity of the groundwater aquifer, in percentages. (6) Guarantee coefficient , which represents the possible leakage rate after a single tracer injection.

3. The liquid leakage source detection method according to claim 1, characterized in that, The detection is performed based on the geographic information model according to preset operating conditions. This includes selecting one or more tracers based on the identification capabilities and screening requirements of existing fluorescent tracer detection equipment, and determining the category of the tracer.

4. The liquid leakage source detection method according to claim 1, characterized in that, After the set operating cycle, the monitoring data of the tracer detection device installed in the downstream groundwater monitoring well is obtained, including: based on the operating conditions, installing the tracer detection device in the downstream groundwater monitoring well; obtaining the background value monitored by the tracer detection device; adding tracer to the upstream investigation point; and obtaining the monitoring data obtained by the tracer detection device at a preset frequency.

5. The liquid leakage source detection method according to claim 4, characterized in that, The system outputs the leakage results of the investigated objects based on the monitoring data. This includes converting the monitoring data into concentration values ​​and simulating the leakage rate; determining the maximum allowable leakage rate of the facility based on at least one of the type, structure, and material of the object under investigation, and comparing and evaluating the degree of leakage of the object under investigation.

6. The liquid leakage source detection method according to claim 5, characterized in that, When the difference in tracer capture concentration in groundwater before and after tracer addition does not exceed three times, the leakage rate of the liquid storage facility shall be calculated using the following formula: In the formula: (1) (1) V represents the leakage rate of the liquid storage facility, in units of %; (2) V represents the liquid storage capacity of the liquid storage facility, in conventional units of m³. 3 (3) C is the average value of the concentration curve captured by the tracer signal detection equipment in the groundwater monitoring well, minus the original cost value, in ppb, 1×10 -9 kg / m 3 (4) K represents the volume correction factor, which is less than 1 and is corrected according to the groundwater flow velocity. When assessing the maximum possible leakage rate of the investigated object, the factor is taken as 1. (5) R represents the distance between the investigation point and the monitoring well, in m. (6) H represents the thickness of the groundwater aquifer, in m. (7) μ represents the porosity of the groundwater aquifer, in %. (8) M represents the amount of tracer added, in kg; When the difference in tracer concentration in groundwater before and after tracer addition is greater than three times, the leakage rate of the investigated object is calculated using the following formula: In the formula: (1) This indicates the leakage rate of the investigated object, in units of % %. (2) μ represents the porosity of the groundwater aquifer, in units of %; (3) A is the receiving cross-sectional area of ​​the tracer groundwater monitoring well, in units of m². 2 (4) V represents the pore flow velocity of groundwater, unit: m / d; (5) C(t) represents the instantaneous concentration of the tracer in the monitoring well. The tracer capture mass is calculated by integrating the concentration curve, unit: kg; (6) M represents the amount of tracer added, unit: kg.

7. A liquid leakage source detection device, characterized in that, include: The data acquisition module is used to acquire geographic information data and on-site survey data of the objects to be investigated; The acquisition of geographic information data and on-site survey data of the object to be investigated includes: acquiring land use information, site information, and existing groundwater monitoring well information of the object to be investigated; acquiring groundwater flow velocity and direction; acquiring groundwater aquifer porosity, aquifer thickness, water storage coefficient, and water conductivity coefficient of the site; and acquiring the water storage volume and water supply and drainage cycle of the liquid storage facilities of the object to be investigated. The modeling module is used to establish a geographic information model based on geographic information data and field survey data. Establishing the geographic information model based on geographic information data and field survey data includes: constructing a three-dimensional geographic model based on the land use information, site information, and existing groundwater monitoring well information of the object to be investigated; assigning parameter values ​​to the geographic element components of the three-dimensional geographic model based on the porosity, thickness, storage coefficient, and permeability coefficient of the groundwater aquifer at the site; and assigning parameter values ​​to the target elements of the three-dimensional geographic model based on the water storage volume and drainage cycle of the liquid storage facilities of the object to be investigated, thereby obtaining the geographic information model. The detection module is used to perform detection based on the geographic information model and preset operating conditions; the detection based on the geographic information model and preset operating conditions includes determining the inspection points for liquid storage facilities within the geographic information model according to the leakage risk level and liquid transport relationship; Based on the distribution of investigation points and existing groundwater monitoring wells in the geographic information model, and combined with the groundwater flow direction relationship, investigation combinations are allocated according to the relationship between investigation points and groundwater monitoring wells. The relationship between investigation points and groundwater monitoring wells represents the relationship between the tracer dosing point and the downstream tracer signal receiving point. Based on the liquid storage capacity and renewal cycle of the liquid storage facilities at the investigation points, as well as the distance between the existing groundwater monitoring wells and the investigation points, the dosage and frequency of the tracer are calculated. The monitoring data acquisition module is used to acquire monitoring data from the tracer detection equipment installed in the downstream groundwater monitoring well after a set operating cycle. The result output module is used to output the leakage results of the investigated object based on the monitoring data.

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