Level detection, early warning method, storage medium and system for radioactive materials

Abstract

The present invention relates to a material level detection and early warning method, storage medium and system for radioactive materials. Firstly, a material level detection simulation model is constructed. Then, according to the simulation results, relationship models between counting rate and different material level heights and relationship models between counting rate and different stockpiling parameters are respectively constructed. Finally, the material level height is determined according to the real-time counting rate combined with the relationship model obtained a priori. Compared with the traditional method of estimating the material level height directly by counting rate, on the one hand, its simulation model can simulate the silo, detection device and material actually used, which is closer to the current material level detection scene. On the other hand, it not only detects the material level height, but also considers the top position of the material level height, that is, the influence of the stockpiling position on the material level height detection. The accuracy of material level detection is improved in all directions, and it is particularly suitable for precise occasions with high requirements for material level accuracy and high requirements for material composition in the silo.

Description

Technical Field

[0001] The present invention relates to the field of material level detection, and in particular to a material level detection and early warning method, storage medium and system for radioactive materials. Background Art

[0002] With the rapid development of industrial automation today, the detection of materials in automated factories cannot be separated from various measuring instruments. The current conventional instruments can solve most of the detection and control requirements. However, due to the characteristics of different industries, many equipment conditions in the production process are in some extremely harsh working environments such as high temperature, high pressure, high dust, high toxicity, and high radioactivity. Some conventional instruments can no longer meet the requirements of the working conditions, so some non-contact detection and control instruments using radioactive isotopes have emerged. According to different uses, radioactive nuclear radiation instruments are divided into density meters, level meters, level switches, etc. They have solved the detection problems of material level, liquid level, and density in different harsh working conditions.

[0003] like Figure 1 As shown, in the detection of radioactive material position, the count rate received is counted through the collimator and the detector. Specifically, the gamma rays of the radioactive material enter the detector and interact with the lanthanum bromide scintillator crystal, causing the crystal to release scintillation light. The scintillation light is absorbed by the photocathode of the photomultiplier tube in the detector, and a photoelectric effect occurs to generate photoelectrons. The photoelectrons pass through the photomultiplier tube, and the multiplied electron beam is collected on the anode to form a current and output a pulse signal. The signal output from the detector is processed by the analog front end, and after preliminary conditioning and amplification by the front-end circuit, it enters the main amplifier, and the signal amplification factor is changed through the programmable gain amplifier, and a peak pulse similar to a Gaussian function is output. Then, the pulse is sampled by a high-speed analog / digital converter (Analog-to-Digital Converter, referred to as ADC), and the amplitude discrimination processing is completed after digital filtering and other processing, and finally a pulse count is formed. The gamma count rate is obtained through software processing. When the radioactive material level measurement count rate is higher than the set threshold, the feeding screw motor is started through the interlocking combination to feed the material, and the external adjustable time relay is triggered to control the feeding time. After the time relay stops, the interlocking feeding motor is automatically turned off, thereby maintaining the material within an allowable and controllable height range.

[0004] However, the above material level detection method is only applicable to some application scenarios where the material level detection accuracy requirements are not high, and is not applicable to some occasions where the detection accuracy requirements are high. Figure 2As shown, when the material falls, due to the repose angle, a conical pile similar to a cone-shaped distribution will be formed in the silo. The difference in the conical pile will directly affect the detection of the material level height. More importantly, for some application scenarios with extremely high detection accuracy, under the same material level height detection condition, the difference in the conical pile will directly affect the quality of the material. Taking the addition of materials to the reactor as an example, the difference in the conical pile will directly affect the quality of the added materials, the concentration of each reactant in the reactor, and the reaction results. If the material level height accuracy requirement is high, the final product will be unqualified, causing great economic losses and even safety hazards.

[0005] Therefore, how to improve the accuracy of material level detection is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0006] In order to solve at least one of the above technical problems, the present invention provides a method for detecting the level of radioactive materials, comprising:

[0007] Construct a material level detection simulation model, including the silo, detection device, and material;

[0008] Simulate the counting rate received by the detection device when the material in the silo is at different material level heights to build a relationship model between the counting rate and different material level heights;

[0009] The counting rate received by the detection device when the materials in the silo are stacked in different cones is simulated to build a relationship model between the counting rate and different stacking parameters; the stacking parameters are parameters that reflect the size of each cross section of the cone stacking;

[0010] The material level height is determined according to the monitored real-time counting rate, combined with the relationship model between the counting rate and different material level heights, and the relationship model between the counting rate and different stockpile parameters.

[0011] Furthermore, the step of constructing a relationship model between the count rate and different material level heights includes:

[0012] Simulate the counting rate received by the detection device when the material in the silo is at different material level heights, and determine the changing curve of the counting rate and material level height;

[0013] According to the variation curve, determining the fitting interval of the detection device;

[0014] In the fitting range, the functional relationship between the counting rate and the material level height is obtained by fitting.

[0015] Furthermore, the step of determining the fitting interval of the detection device according to the change curve includes:

[0016] Calculate the slope at each point on the change curve;

[0017] As the horizontal axis moves to the left, determine whether the slope exceeds the set threshold;

[0018] The material level height when the slope exceeds the set threshold for the first time is taken as the lower limit of the fitting interval, and the material level height when the slope falls below the set threshold again is taken as the upper limit of the fitting interval to determine the fitting interval of the detection device.

[0019] Furthermore, within the fitting interval, the functional relationship between the count rate and the material level height is obtained by fitting, specifically:

[0020] By reducing the step size of the change curve within the fitting interval, a linear function between the count rate and the material level height is obtained by fitting, as shown in formula (1):

[0021] (1)

[0022] Among them, n is the counting rate received by the detection device, h is the material level height, and k and b are constants.

[0023] Furthermore, the step of constructing a relationship model between the counting rate and different stockpiling parameters includes:

[0024] When the materials in the simulated silo are stacked in different conical shapes, the detection device is moved up and down to count the count rates received at different positions and determine the change curve of the count rate and the stacking parameters;

[0025] According to the changing curve, the functional relationship between the counting rate and the pile parameters is obtained by fitting.

[0026] Furthermore, the step of determining the material level height includes:

[0027] Get the real-time counting rate at the silo, and roughly locate the height by combining the relationship model between the counting rate and different material level heights;

[0028] According to the rough positioning height, the precise positioning interval is determined, and the precise positioning interval is divided into several measurement intervals;

[0029] Obtain the real-time counting rate at each measuring interval, and determine the stockpiling parameters at each measuring interval by combining the relationship model between the counting rate and different stockpiling parameters;

[0030] The material level height is determined based on the rough positioning height and the material pile parameters at each measuring interval.

[0031] Furthermore, the material level height is determined using formula (3):

[0032] (3)

[0033] Among them, H is the material level height, H0 is the rough positioning height; β a is the stockpile parameter of the ath measurement interval; B is the silo parameter; A is the number of measurement intervals; da is the height of the ath measurement interval.

[0034] On the other hand, the present invention also provides a material level warning method, which uses any of the above-mentioned material level detection methods to determine the material level height;

[0035] When the material level is lower than the lower limit or higher than the upper limit, a material level warning is issued.

[0036] On the other hand, the present invention further provides a computer-readable storage medium on which is stored a computer program for executing any of the above-mentioned material level detection methods; or a computer program for executing any of the above-mentioned material level warning methods.

[0037] On the other hand, the present invention also provides a computer system, comprising any of the above-mentioned computer-readable storage media and one or more processors;

[0038] The processor is configured to run the computer program.

[0039] The present invention provides a material level detection and early warning method, storage medium and system for radioactive materials. First, a material level detection simulation model is constructed. Then, according to the simulation results, relationship models between counting rate and different material level heights and relationship models between counting rate and different stockpiling parameters are respectively constructed. Finally, the material level height is determined according to the real-time counting rate combined with the a priori relationship model. Compared with the traditional method of estimating the material level height directly by counting rate, on the one hand, its simulation model can simulate the silo, detection device and material actually used, which is closer to the current material level detection scene. On the other hand, it not only detects the material level height, but also considers the top position of the material level height, that is, the influence of the conical stockpiling on the material level height detection. The accuracy of material level detection is improved in all directions, and it is particularly suitable for precise occasions with high requirements for material level accuracy and high requirements for material composition in the silo. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of the structure of an embodiment for measuring count rate of a collimator and a detector;

[0041] Figure 2 It is a structural schematic diagram of an embodiment of a conical pile;

[0042] Figure 3 A flow chart of an embodiment of the material level detection method of the present invention;

[0043] Figure 4 A schematic diagram of the structure of an embodiment of the simulation model of the present invention;

[0044] Figure 5 It is a curve diagram of the change of counting rate and material level height;

[0045] Figure 6 It is the curve diagram of the change of counting rate and material level height in the fitting interval;

[0046] Figure 7 It is a structural schematic diagram of an embodiment of a simulation model of a conical pile of materials according to the present invention;

[0047] Figure 8 This is a curve chart of the change in counting rate and conical pile. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] It should be noted that if the embodiments of the present invention involve directional indications, such as up, down, left, right, front, back, etc., then the directional indication is only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly. In addition, if the embodiments of the present invention involve descriptions of "first, second", "S1, S2", "step one, step two", etc., then such descriptions are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of indicated technical features or indicating the execution order of the method, etc. Those skilled in the art can understand that anything that does not violate the gist of the invention under the technical concept of the invention should be included in the protection scope of the present invention.

[0050] like Figure 3 As shown, the present invention provides a method for detecting the level of radioactive materials, comprising:

[0051] S1: Construct a material level detection simulation model, including the silo, detection device and materials;

[0052] Specifically, the simulation software may be Geant4; the simulation method may be the Monte Carlo method; a silo model for storing radioactive materials, a detection device model for detecting the counting rate of radioactive materials, and a stored material model are constructed respectively, such as Figure 4 shown.

[0053] Preferably, the silo simulation model includes setting the silo wall composition, density and size; the detection device simulation model includes the collimator size and shielding thickness, detector crystal type and size; the material model includes material composition, density, etc.

[0054] Example:

[0055] Silo: It can be a cylindrical pipe, that is, the pipe to be tested: preferably, the pipe wall material: Monel400 alloy, element mass fraction Ni63%, Cu32.5%, Fe2.5%, Mn2%, density 8.8g / cm3; pipe size: Φ114.3mm×6.3mm;

[0056] Detection device: collimator and detector can be selected, collimator: collimation hole size Φ10mm×200mm, Pb shielding layer thickness 54mm; detector: crystal NaI, size Φ38mm×38mm;

[0057] Material: Place the material in the pipeline, with the center of the collimation hole as the 0 point, the bottom of the material set at -100cm, the distance from the top of the material to the center of the collimation hole is h, the h range is [-60cm, 80cm], and the radioactivity is A:

[0058]

[0059] Where h is the distance between the top of the material and the center of the collimation hole, which can be selected as h∈[-60cm,80cm]; r is the material radius, which can be selected as 10.17cm; ρ is the material density, which can be selected as 0.7g / cm3; NA is the Avogadro constant, which can be selected as 6.02×10 23 ;λ is the decay constant, and the U235 decay constant 3.10×10 -17 , η is the ray branching ratio, and the 185keV ray branching ratio can be selected as 54%. N is the average molecular weight, and the UF4 average molecular weight can be selected as 314.02.

[0060] Simulate the counting rate received by the detection device when the material in the silo is at different material level heights to build a relationship model between the counting rate and different material level heights;

[0061] Specifically, after the simulation model is constructed, the counting rate received by the detection device when the material in the silo is at different material level heights is simulated, the simulation results are counted, the law between the counting rate and the material level height is sought, and a relationship model between the two is constructed. More specifically, the relationship model can be optionally represented by a fitting function, a mapping table, etc.

[0062] Preferably, step S2 comprises:

[0063] S21: simulating the counting rate received by the detection device when the material in the silo is at different material level heights, and determining a variation curve of the counting rate and the material level height;

[0064] S22: Determine the fitting interval of the detection device according to the change curve;

[0065] S23: Within the fitting interval, a functional relationship between the counting rate and the material level height is obtained by fitting.

[0066] Specifically, the center position of the detector is set as the 0 point, the material level height of the bottom of the material from the 0 point is set to -80 to 0, and the material level height of the top of the material from the 0 point is set to 0 to 100, and the count rate received by the detection device is recorded respectively, and the change curve of the count rate and the material level height is plotted, such as Figure 5 As shown;

[0067] According to Figure 5 From the change curve shown, it is found that outside a certain range from point 0, the increase or decrease of materials has little effect on the counting rate. If this part of data is added for subsequent fitting, the accuracy of the fitting function will be greatly reduced, and the accuracy of subsequent material level prediction will be reduced. Therefore, the present invention preferably adopts step S22, firstly, according to the change curve, the fitting interval of the detection device is determined; then, within the fitting interval, the functional relationship between the counting rate and the material level height is obtained by fitting, which can not only improve the authenticity of the fitting function and better reflect the actual situation of the relationship between the two, and improve the accuracy of subsequent material level prediction, but also simplify the complexity of the function, without the need to use piecewise functions, etc. for representation, thereby improving the efficiency of material level prediction.

[0068] Specifically, Figure 5 As shown, the fitting interval of the detection device can be directly observed, but the change curve obtained by the simulation is obtained by simulation under the condition that the above simulation parameters are fixed. If the parameters of the silo, detection device, and material models are changed, the simulation results will inevitably be different each time, and the fitting interval of the detection device needs to be re-determined.

[0069] Preferably, step S22 may optionally include:

[0070] S221: Calculate the slope of each point on the change curve;

[0071] S222: As the horizontal axis moves to the left, determine whether the slope exceeds a set threshold;

[0072] S223: The material level height when the slope exceeds the set threshold for the first time is used as the lower limit of the fitting interval, and the material level height when the slope falls below the set threshold again is used as the upper limit of the fitting interval to determine the fitting interval of the detection device.

[0073] Specifically, Figure 6 As shown, for Figure 5 The variation curve shown can be determined to have a fitting interval of: h in the interval [-20, 20]. The simulation data and the variation curve in this interval can be fitted to obtain a functional relationship between the two.

[0074] Preferably, step S23 may optionally include:

[0075] By reducing the step size of the change curve within the fitting interval, a linear function between the count rate and the material level height is obtained by fitting, as shown in formula (1):

[0076] (1)

[0077] Among them, n is the counting rate received by the detection device, h is the material level height, and k and b are constants.

[0078] In this embodiment, if Figure 5 As shown, the step size of h can be optionally reduced in the interval [-20, 20] to obtain the simulation results in the fitting interval, such as Figure 6 As shown, within this range, the material level height and the detector count have a good linear relationship.

[0079] S3: The counting rate received by the detection device when the materials in the silo are stacked in different conical shapes is simulated to build a relationship model between the counting rate and different stacking parameters; the stacking parameters are parameters that reflect the size of each cross section of the conical stacking;

[0080] Specifically, after constructing the simulation model, under different conical pile conditions, such as Figure 7 As shown, the counting rate received by the detection device is statistically analyzed to find the law between the counting rate and the stacking parameters, so as to construct a relationship model between the counting rate and different stacking parameters. More specifically, the stacking parameter is any parameter that can reflect the cross-sectional size at each height of different conical stacking materials, which can be selected but not limited to the radius, diameter, cross-sectional area, etc. of each cross section.

[0081] Preferably, step S3 includes:

[0082] S31: When materials in the simulated silo are stacked in different conical shapes, the detection device is moved up and down to count the count rates received at different positions, and the change curve of the count rate and the stacking parameters is determined;

[0083] Specifically, Figure 1 As shown, when the material falls, due to the repose angle, a conical pile similar to a cone distribution will be formed in the silo. Since the cross-sections of the conical pile at each height are different and the amount of material contained is different, the signal measured by the level meter at different heights of the conical material is different. When simulating different conical piles, the detection device moves up and down and will receive a changing measurement signal, that is, a changing counting rate, and determine the changing curve of the counting rate and the pile parameters to reflect the differential shape of the pile.

[0084] More preferably, the stacking parameters may be, but are not limited to, material radius, material cross-sectional area, etc.; Figure 8 As shown, according to the simulation results, the counting rate received by the detection device when the pile radius is 1-6 cm is counted, and a curve of the counting rate changing with the pile radius distribution is obtained.

[0085] S32: According to the variation curve, a functional relationship between the counting rate and the stockpile parameters is obtained by fitting.

[0086] Specifically, Figure 8 As shown in Figure 2, the distribution relationship between the counting rate n and the pile radius r is logarithmic, as shown in formula (2):

[0087] ,Right now (2)

[0088] It is worth noting that the various parameters of the logarithmic function are related to the size of the silo, the concentration of the radioactive material contained, the radiation level, the performance of the shielding device, etc. The logarithmic relationship shown in formula (2) is only the logarithmic function relationship obtained under the conditions of this simulation. According to convention, 0.8408 and 1.50185 can be selected to be represented by letter parameters.

[0089] S4: Determine the material level height according to the monitored real-time counting rate, combined with the relationship model between the counting rate and different material level heights, and the relationship model between the counting rate and different stockpiling parameters.

[0090] Specifically, a detector can be set at a suitable installation position of a silo, such as the side of a reactor silo section, away from the silo; a heat insulation component can be optionally installed at the front end of the detector to ensure that the operating temperature of the equipment does not exceed 65°C. If the temperature is too high, an air cooling device can be optionally added to provide an air source to enhance the cooling effect; more preferably, a radiation shielding structure can be optionally added on the measurement path to reduce the interference and damage of the equipment to radiation and improve the stability and service life of the system; relative to the traditional point source measurement method, the system does not require a radioactive source, reducing the procurement and management costs of the source; more preferably, a lanthanum bromide detector can be optionally used, which has a high energy resolution and a 1.4MeV background γ peak, which can be used to stabilize the peak and improve the stability of the system. Traditionally, sodium iodide crystals are used, and an a source equivalent γ source is needed as a peak stabilization source to stabilize the peak. The a source is easily affected by the crystal packaging material magnesium oxide powder and fails. Through the above settings, a detection device is used to detect the real-time counting rate at the silo, and the relationship model between the counting rate and different material level heights and the relationship model between the counting rate and different stacking parameters obtained in steps S2 and S3 are combined, and the real-time counting rate is substituted to determine the material level height.

[0091] Preferably, step S4 may optionally include:

[0092] S41: obtaining the real-time counting rate at the silo, combining the relationship model between the counting rate and different material level heights, and roughly locating the height;

[0093] Specifically, in a preferred embodiment, the real-time counting rate can be optionally substituted into the linear function determined in step S2 to determine the real-time material level height h.

[0094] S42: determining a precise positioning interval according to the rough positioning height, and dividing the precise positioning interval into a plurality of measurement intervals;

[0095] Specifically, the fine positioning interval, i.e. the position of the material pile, can be determined by moving up and down a few mm based on the rough positioning height. For example, the collimation hole diameter is 10 mm, and assuming that the detector lead shielding efficiency is 100%, the detector can only receive gamma rays emitted by the material with a height of 10 mm near the collimation hole. Figure 1 The height of the shaded part is 10mm, which is the position of the pile, and the precise positioning interval is divided into several measuring intervals. For example, every 2mm is determined as a measuring interval, and the precise positioning interval is divided into 5 measuring intervals; or Figure 1 As shown, each 1 mm is determined as a measurement interval, and the precise positioning interval is divided into 10 measurement intervals.

[0096] S43: obtaining the real-time counting rate at each measuring interval, and determining the stockpiling parameters at each measuring interval by combining the relationship model between the counting rate and different stockpiling parameters.

[0097] Specifically, the detection device is moved to each measuring interval, and the real-time counting rate at each location is measured. The relationship model between the counting rate and the stockpiling parameters, such as the material radius and the material cross-sectional area, is combined, and preferably substituted into the functional relationship determined in step S3 to determine the stockpiling parameters at each measuring interval, such as the material radius, etc., and the distribution of the material radius at the overall height of the measuring interval is obtained, so as to determine the specific shape of the conical stockpiling, such as the height of the conical stockpiling, the radius of the cross section at each height, the cross-sectional area, etc.

[0098] S44: Obtaining the material level height according to the rough positioning height and the material stock parameters at each measuring interval.

[0099] Specifically, the final material level height can be obtained by fitting according to the rough positioning height and the material pile parameters at each measuring interval, such as the material pile radius, etc. In the example, the material in the form of a pile is hypothetically spread to the cross section of the silo to form a full plane, and the final material level height obtained by fitting is the real and accurate material level height; more specifically, the material level height can be determined by formula (3):

[0100] (3)

[0101] Among them, H is the material level height, H0 is the rough positioning height; β a is the stockpile parameter of the ath measurement interval; B is the silo parameter; for example, if the stockpile parameter takes the stockpile radius of a certain measurement interval, the silo parameter is the actual radius of the silo; A is the number of measurement intervals; d a is the height of the ath measurement interval.

[0102] In summary, the present invention provides a material level detection method for radioactive materials, which first constructs a material level detection simulation model, and then, based on the simulation results, respectively constructs a relationship model between the counting rate and different material level heights and a relationship model between the counting rate and different stockpiling parameters; finally, the material level height is determined based on the real-time counting rate combined with the a priori obtained relationship model; compared with the traditional method of estimating the material level height directly by the counting rate, on the one hand, its simulation model can be simulated for the actual silo, detection device and material used, which is closer to the actual current material level detection scene; on the other hand, it not only detects the material level height, but also considers the top position of the material level height, that is, the influence of the stockpiling position on the material level height detection; the accuracy of material level detection is improved in all directions, and it is particularly suitable for precise occasions with high requirements for material level accuracy and high requirements for material composition in the silo.

[0103] On the other hand, the present invention also provides a material level early warning method, which uses any one of the above-mentioned material level detection methods to determine the material level height;

[0104] When the material level is lower than the lower limit or higher than the upper limit, a material level warning is issued.

[0105] Specifically, non-contact fixed-point detection of the upper and lower material points of the silo can be selected. The specific detection steps are as follows:

[0106] 1) Determine the background signal when there is no material in the silo, that is, the background γ count rate N0 measured by the detector. For materials that are not attached to the wall or have stable measurement conditions, background measurement and equipment are not required.

[0107] 2) Determine the measurement signal when the silo is full, that is, the detector measures the gamma count rates Nu and Np at the upper and lower limit positions.

[0108] 3) Determine the upper and lower alarm values ​​of the material. Set the upper and lower alarm thresholds to A and B respectively, Nu-N0=A, Np-N0=B. The actual thresholds can be slightly smaller than the measured A and B to avoid untimely response of the equipment.

[0109] According to the material level detection method of the present invention, the current value X of the upper and lower positions is detected. 上 , X 下

[0110] When X 下 When ≤B, it means that the material has reached the lower limit point and a lower limit alarm signal is given. The processor outputs the measured signal to other prompt devices or systems, such as sound and light alarms, PLC, DCS and other systems.

[0111] When X 上When ≥A, it means that the material has reached the upper limit point, and then judge whether there is an alarm at the lower limit. If the lower limit also alarms, an upper limit alarm signal is given, and the processor outputs the measured signal to other prompt devices or systems, such as sound and light alarms, PLC, DCS and other systems. At the same time, it can also be linked with other equipment, such as controlling the valve of the feeding channel or opening the valve of the unloading channel.

[0112] On the other hand, the present invention further provides a computer storage medium storing executable program code; the executable program code is used to execute any of the above-mentioned material level detection methods or early warning methods.

[0113] On the other hand, the present invention further provides a terminal device, including a memory and a processor; the memory stores program codes that can be executed by the processor; the program codes are used to execute any of the above-mentioned material level detection methods or early warning methods.

[0114] Exemplarily, the program code may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the program code in the terminal device.

[0115] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that the terminal device may also include an input / output device, a network access device, a bus, etc.

[0116] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0117] The memory may be an internal storage unit of the terminal device, such as a hard disk or a memory. The memory may also be an external storage device of the terminal device, such as a plug-in hard disk, a smart memory card (SmartMedia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the terminal device. Further, the memory may also include both an internal storage unit of the terminal device and an external storage device. The memory is used to store the program code and other programs and data required by the terminal device. The memory may also be used to temporarily store data that has been output or is to be output.

[0118] The above-mentioned image recognition method, computer storage medium and terminal device are created based on the above-mentioned data generation method, and their technical functions and beneficial effects are no longer repeated here. The various technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0119] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for detecting the level of radioactive materials, characterized in that: include: Construct a material level detection simulation model, including the silo, detection device, and material; Simulate the counting rate received by the detection device when the material in the silo is at different material level heights to build a relationship model between the counting rate and different material level heights; The counting rate received by the detection device when the materials in the silo are stacked in different cones is simulated to build a relationship model between the counting rate and different stacking parameters; the stacking parameters are parameters that reflect the size of each cross section of the cone stacking; According to the real-time count rate monitored, the material level height is determined by combining the relationship model between the count rate and different material level heights, and the relationship model between the count rate and different stockpile parameters; including: Get the real-time counting rate at the silo, and roughly locate the height by combining the relationship model between the counting rate and different material level heights; According to the rough positioning height, the precise positioning interval is determined, and the precise positioning interval is divided into several measurement intervals; Obtain the real-time counting rate at each measuring interval, and determine the stockpiling parameters at each measuring interval by combining the relationship model between the counting rate and different stockpiling parameters; The material level height is determined based on the rough positioning height and the material pile parameters at each measuring interval.

2. The material level detection method according to claim 1, characterized in that: The steps to construct a model of the relationship between count rate and different material level heights include: Simulate the counting rate received by the detection device when the material in the silo is at different material level heights, and determine the changing curve of the counting rate and material level height; According to the variation curve, determining the fitting interval of the detection device; In the fitting range, the functional relationship between the counting rate and the material level height is obtained by fitting.

3. The material level detection method according to claim 2, characterized in that: The step of determining the fitting interval of the detection device according to the change curve comprises: Calculate the slope at each point on the change curve; As the horizontal axis moves to the left, determine whether the slope exceeds the set threshold; The material level height when the slope exceeds the set threshold for the first time is taken as the lower limit of the fitting interval, and the material level height when the slope falls below the set threshold again is taken as the upper limit of the fitting interval to determine the fitting interval of the detection device.

4. The material level detection method according to claim 2, characterized in that: In the fitting range, the functional relationship between the counting rate and the material level height is obtained by fitting, specifically: By reducing the step size of the change curve within the fitting interval, a linear function between the count rate and the material level height is obtained by fitting, as shown in formula (1): （1）； Among them, n is the counting rate received by the detection device, h is the material level height, and k and b are constants.

5. The material level detection method according to claim 1, characterized in that: The steps of constructing a model of the relationship between count rate and different stockpile parameters include: When materials in the simulated silo are piled in different cone shapes, the detection device is moved up and down to count the count rates received at different positions and determine the change curve of the count rate and the pile parameters; According to the changing curve, the functional relationship between the counting rate and the pile parameters is obtained by fitting.

6. The material level detection method according to any one of claims 1 to 5, characterized in that: Use formula (3) to determine the material level: （3） Among them, H is the material level height, H0 is the rough positioning height; β a is the stockpile parameter of the ath measurement interval; B is the silo parameter; A is the number of measurement intervals; d a is the height of the ath measurement interval.

7. A material level early warning method, characterized in that: Adopting the material level detection method according to any one of claims 1 to 6 to determine the material level height; When the material level is lower than the lower limit or higher than the upper limit, a material level warning is issued.

8. A computer-readable storage medium, characterized in that: A computer program for executing the material level detection method according to any one of claims 1 to 6; or a computer program for executing the material level warning method according to claim 7 is stored thereon.

9. A computer system, characterized in that: comprising the computer-readable storage medium of claim 8 and one or more processors; The processor is configured to run the computer program.

Images