A liquid level monitoring method and system based on a radar liquid level meter

Abstract

The present application belongs to the technical field of liquid level monitoring, and relates to a liquid level monitoring method and system based on a radar liquid level meter. The present application matches the dielectric constant of the current temperature of the stored substance in the target storage tank, thereby judging whether the dielectric constant is abnormal. The influence of temperature on the dielectric constant of the stored substance is considered, and the error of the radar liquid level meter in monitoring the liquid level caused by temperature change is avoided. Whether the key obstacles in the target storage tank have an abnormal influence on the monitoring process of the radar liquid level meter is evaluated from multiple dimensions, thereby breaking the limitation of single parameter analysis, reducing the measurement error caused by obstacle abnormalities, and ensuring the stability of liquid level monitoring. Whether foam interference or steam interference occurs during the monitoring of the radar liquid level meter is identified through multiple verification methods, thereby improving the accuracy of interference cause identification, ensuring the pertinence of maintenance measures, and avoiding the decline of the measurement accuracy of the radar liquid level meter caused by abnormal medium characteristics.

Description

Technical Field

[0001] This invention belongs to the field of liquid level monitoring technology, and relates to a liquid level monitoring method and system based on a radar liquid level gauge. Background Technology

[0002] A radar level gauge is a high-precision, non-contact level measurement instrument based on microwave technology. Its core principle is to emit high-frequency electromagnetic waves and receive the echoes reflected from the surface of the measured medium, combining this with the time-of-flight method or frequency-modulated continuous wave technology to calculate the liquid level. Compared to traditional contact level gauges, radar level gauges have the advantages of being unaffected by the viscosity, density, or corrosiveness of the medium, and do not require direct contact with the measured medium, making them suitable for extreme conditions such as high temperature, high pressure, strong corrosion, and flammable and explosive environments.

[0003] Existing radar level gauge-based liquid level monitoring technologies can meet basic usage requirements, but there are still some shortcomings: on the one hand, existing solutions lack consideration of whether temperature affects the dielectric constant of the stored material, which may lead to errors in radar level gauge monitoring due to temperature changes.

[0004] On the other hand, existing solutions lack the ability to detect and analyze the impact of obstacles in the radar wave propagation path, which makes it difficult to identify echo signal interference and affects measurement accuracy. Furthermore, existing technologies also ignore the interference of changes in the properties of media such as foam and steam on the accuracy of radar level gauge measurement, resulting in a high misjudgment rate and hindering the stability and accuracy of level monitoring. Summary of the Invention

[0005] In view of this, in order to solve the problems mentioned in the background art, a liquid level monitoring method and system based on radar level gauge is proposed.

[0006] The objective of this invention can be achieved through the following technical solution: The first aspect of this invention provides a liquid level monitoring method based on a radar level gauge, comprising: S1, data detection: collecting the dielectric constant and current temperature of the material stored in the target tank according to a preset fixed detection cycle, and simultaneously acquiring the appearance status data of several key obstacles affecting radar wave propagation in the target tank and the echo parameter data of the radar level gauge in the target tank during liquid level monitoring.

[0007] S2. Dielectric constant anomaly judgment: Based on the dielectric constant and the current temperature, determine whether the dielectric constant is abnormal according to the dielectric constant-temperature mapping curve. If abnormal, trigger the obstacle state anomaly detection process and the dielectric property anomaly detection process at the same time.

[0008] S3. Obstacle Status Anomaly Detection: Based on the appearance status data, determine whether the status of several key obstacles is abnormal through obstacle anomaly assessment rules. If abnormal, trigger corresponding management measures.

[0009] S4. Detection of abnormal media characteristics: Based on the echo parameter data, the radar level gauge determines whether there is foam interference or steam interference in the media characteristics during level monitoring by using the media abnormality diagnosis rules. If an abnormality is found, corresponding maintenance measures are triggered.

[0010] S5. Level gauge calibration monitoring: Based on the dielectric constant of the current temperature of the material stored in the target tank after maintenance and management, the electromagnetic wave propagation speed of the radar level gauge in the target tank is corrected, and the level value currently monitored and output by the radar level gauge is read.

[0011] A second aspect of this invention provides a liquid level monitoring system based on a radar level gauge, comprising: a data detection module, a dielectric constant anomaly judgment module, an obstacle state anomaly detection module, a medium property anomaly detection module, a level gauge calibration monitoring module, and a database. The modules are connected as follows: the data detection module is connected to the dielectric constant anomaly judgment module; the dielectric constant anomaly judgment module is connected to both the obstacle state anomaly detection module and the medium property anomaly detection module; the obstacle state anomaly detection module and the medium property anomaly detection module are connected to the level gauge calibration monitoring module; and the database is connected to the dielectric constant anomaly judgment module.

[0012] The data detection module collects the dielectric constant and current temperature of the material stored in the target tank according to a preset fixed detection cycle. It also simultaneously acquires the appearance status data of several key obstacles affecting radar wave propagation in the target tank, as well as the echo parameter data of the radar level gauge in the target tank during level monitoring.

[0013] The dielectric constant anomaly detection module determines whether the dielectric constant is abnormal based on the dielectric constant and the current temperature, according to the dielectric constant-temperature mapping curve. If abnormal, it simultaneously triggers the obstacle state anomaly detection process and the dielectric property anomaly detection process.

[0014] The obstacle status anomaly detection module determines whether the status of several key obstacles is abnormal based on the appearance status data and obstacle anomaly assessment rules. If an anomaly is detected, corresponding management measures are triggered.

[0015] The medium characteristic anomaly detection module, based on the echo parameter data, determines whether there is foam interference or steam interference in the medium characteristics of the radar level gauge during level monitoring through medium anomaly diagnosis rules. If an anomaly is found, corresponding maintenance measures are triggered.

[0016] The liquid level gauge calibration and monitoring module corrects the electromagnetic wave propagation speed of the radar liquid level gauge in the target storage tank based on the dielectric constant matched with the current temperature of the stored material in the target storage tank after maintenance and management, and reads the liquid level value currently monitored and output by the radar liquid level gauge.

[0017] The database stores dielectric constant-temperature mapping curves.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention matches the dielectric constant of the material stored in the target storage tank with the current temperature, and judges whether the detected dielectric constant is abnormal. It fully considers the influence of temperature on the dielectric constant of the stored material and avoids the error of radar level gauge monitoring liquid level caused by temperature change.

[0019] 2. This invention assesses whether several key obstacles in the target storage tank have an abnormal impact on the monitoring process of the radar level gauge from multiple dimensions, including structural deformation, material accumulation thickness, and scale thickness. When an abnormal impact occurs, corresponding management measures are triggered. This breaks through the limitations of single-parameter analysis, helps to reduce measurement errors caused by abnormalities in key obstacles, and ensures the stability of level monitoring.

[0020] 3. This invention identifies whether foam or steam interference occurs when the radar level gauge monitors the liquid level through a triple verification method of echo curve, echo quality index and dielectric constant. When interference occurs, corresponding maintenance measures are triggered, which improves the accuracy of interference cause identification, ensures the pertinence of maintenance measures, and avoids the decrease in radar level gauge measurement accuracy caused by abnormal medium characteristics. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram illustrating the implementation steps of the method of the present invention.

[0023] Figure 2 This is a schematic diagram of the system module connections of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1

[0026] See Figure 1 As shown, the present invention provides a liquid level monitoring method based on a radar level gauge. The specific steps are as follows: S1, Data detection: According to a preset fixed detection cycle, the dielectric constant of the material stored in the target tank and the current temperature are collected. At the same time, the appearance status data of several key obstacles affecting the propagation of radar waves in the target tank and the echo parameter data of the radar level gauge in the target tank during liquid level monitoring are obtained.

[0027] It should be noted that the dielectric constant and current temperature of the substance stored in the target storage tank are obtained by detecting the liquid level of the substance stored in the target storage tank using a radar level gauge. Further according to the formula The electromagnetic wave velocity at the current radar level gauge detection time is calculated. ,in The interval between when the radar level gauge transmits and receives electromagnetic waves is further calculated using the formula... The dielectric constant of the material stored in the target storage tank was calculated. ,in The speed of light in a vacuum; the current temperature is obtained directly by a temperature sensor.

[0028] It should be explained that the dielectric constant is an inherent property determined by the physicochemical properties of the substance stored in the target tank, and will not change due to surface scaling or deformation of obstacles. The dielectric constant anomaly mentioned in this invention refers to an abnormality in the state of the obstacle or the characteristics of the medium, which interferes with the propagation and reflection of electromagnetic waves when the radar level gauge monitors the liquid level, thus causing the measurement results to appear as if they are "abnormally dielectric constant."

[0029] In one specific example, the key obstacles include, but are not limited to, support structures such as support beams and brackets inside the storage tank, as well as waveguides and stirring devices.

[0030] The appearance status data includes, but is not limited to, structural deformation degree, surface material thickness, and surface scale thickness at each monitoring point.

[0031] It should be noted that each monitoring point refers to the intersection point obtained by dividing the surface of the supporting structures such as support beams and brackets inside the storage tank, as well as key obstacles such as waveguides and stirring devices, into a grid.

[0032] The specific method for obtaining the structural deformation degree, surface material thickness, and surface scale thickness at each monitoring point is as follows: several key obstacles are detected by integrated sensors deployed inside the target storage tank, and the structural deformation degree is the ratio of the deformed area of ​​the key obstacle to its total area. The integrated sensors include laser rangefinders, ultrasonic thickness gauges, eddy current probes, etc. The specific detection process of these integrated sensors is relatively mature in existing technologies and will not be elaborated here.

[0033] The echo parameter data includes, but is not limited to, echo curves, echo quality indices, and dielectric constants.

[0034] It should be noted that the specific methods for obtaining the echo curve, echo quality index, and dielectric constant are as follows: the echo curve is directly acquired by the radar level gauge inside the target storage tank, the echo quality index is calculated by the radar level gauge inside the target storage tank, and the method for obtaining the dielectric constant is the same as the method for obtaining the dielectric constant of the material stored in the target storage tank. The specific detection process of the radar level gauge is relatively mature in the existing technology and will not be described in detail here.

[0035] S2. Dielectric constant anomaly judgment: Based on the dielectric constant and the current temperature, determine whether the dielectric constant is abnormal according to the dielectric constant-temperature mapping curve. If abnormal, trigger the obstacle state anomaly detection process and the dielectric property anomaly detection process at the same time.

[0036] As a preferred feasible embodiment, the specific process of determining whether the dielectric constant is abnormal includes: comparing the current temperature of the material stored in the target tank with the dielectric constant-temperature mapping curve to determine the dielectric constant of the material stored in the target tank, and recording it as the current standard dielectric constant of the material stored in the target tank; if the dielectric constant of the material stored in the target tank is inconsistent with it, then the dielectric constant of the material stored in the target tank is recorded as abnormal.

[0037] It should be noted that the dielectric constant-temperature mapping curve is a curve used to characterize the relationship between the dielectric constant of the material stored in the target storage tank and its temperature, reflecting the variation law of the dielectric constant of the stored material under different temperature conditions.

[0038] Furthermore, the dielectric constant-temperature mapping curve is extracted from the database. The dielectric constant-temperature mapping curve is obtained by fitting experimental data on the relationship between dielectric constant and temperature in the laboratory, and then stored in the database.

[0039] It should be further explained that the specific process of determining the dielectric constant of the material stored in the target storage tank is as follows: if the dielectric constant-temperature mapping curve is a mathematical expression, then the current temperature of the material stored in the target storage tank is substituted into the mathematical expression of the curve to calculate the corresponding dielectric constant.

[0040] If the dielectric constant-temperature mapping curve is in tabular form, find the temperature point in the table that is closest to the current temperature of the substance stored in the target tank, and take the dielectric constant value corresponding to that temperature point as the current standard dielectric constant; if the current temperature of the substance stored in the target tank is between two adjacent temperature points, the current standard dielectric constant can be calculated using linear interpolation.

[0041] This invention matches the dielectric constant of the substance stored in the target tank with its current temperature, and determines whether the detected dielectric constant is abnormal. It fully considers the influence of temperature on the dielectric constant of the stored substance and avoids errors in radar level gauge monitoring caused by temperature changes.

[0042] S3. Obstacle Status Anomaly Detection: Based on the appearance status data, determine whether the status of several key obstacles is abnormal through obstacle anomaly assessment rules. If abnormal, trigger corresponding management measures.

[0043] As a preferred feasible embodiment, the specific content of the obstacle anomaly assessment rule includes: extracting the structural deformation degree of several key obstacles affecting radar wave propagation inside the target storage tank from the appearance status data, as well as the surface material thickness and surface fouling thickness at each monitoring point, and inputting them into the single-parameter anomaly judgment rule and the multi-parameter coupled anomaly judgment rule to which the obstacle anomaly assessment rule belongs, and outputting the judgment results of the single-parameter anomaly judgment rule and the multi-parameter coupled anomaly judgment rule of the appearance status data.

[0044] As a preferred feasible embodiment, the specific content of the single-parameter anomaly determination rule includes: comparing the structural deformation degree of several key obstacles affecting radar wave propagation inside the target storage tank with a set structural deformation degree safety threshold; if the structural deformation degree of a certain key obstacle is greater than the set structural deformation degree safety threshold, then the state of the key obstacle is recorded as structural anomaly, and this is recorded as the determination result of the single-parameter anomaly determination rule for the key obstacle. Similarly, the states of the several key obstacles are obtained as structural anomaly, material accumulation anomaly, or scaling anomaly, and the determination result of the single-parameter anomaly determination rule for the several key obstacles is determined accordingly.

[0045] As a preferred feasible embodiment, the specific content of the multi-parameter coupling anomaly determination rule includes: obtaining the multi-parameter composite anomaly coefficient of the several key obstacles according to the multi-parameter composite anomaly coefficient calculation formula, comparing them with the preset multi-parameter composite anomaly coefficient threshold respectively, and if the multi-parameter composite anomaly coefficient of a certain key obstacle is greater than or equal to the preset multi-parameter composite anomaly coefficient threshold, then the state of the key obstacle is recorded as abnormal, and it is recorded as the determination result of the multi-parameter coupling anomaly determination rule of the key obstacle, thereby determining the determination result of the multi-parameter coupling anomaly determination rule of the several key obstacles.

[0046] It should be further explained that the specific formula for calculating the multi-parameter composite anomaly coefficient is as follows: ,in These are the structural deformation degrees of key obstacles affecting radar wave propagation within the target storage tank and the first The surface deposit thickness and surface scale thickness at each monitoring point These are the safety thresholds for structural deformation, surface material thickness, and surface scale thickness, respectively. These are the weighting coefficients corresponding to structural deformation degree, surface material thickness, and surface scale thickness, respectively. , Number each monitoring point This represents the number of monitoring points.

[0047] A specific example, suppose They are 0.1mm, 5mm and 3mm respectively. The values ​​are 0.5, 0.3, and 0.2 respectively. Examples of multi-parameter composite anomaly coefficient calculations are shown in Table 1 below.

[0048] Table 1. Example of multi-parameter composite anomaly coefficient calculation

[0049] Group Structural Deformation Maximum material accumulation at monitoring point Maximum scaling at monitoring point Multi-parameter composite anomaly coefficient 1 0.08 3mm 2mm 0.8 0.6 0.67 0.644 2 0.15 4mm 1mm 1.5 0.8 0.33 0.956 3 0.12 6mm 3mm 1.2 1.2 1.0 1.16 4 0.05 8mm 4mm 0.5 1.6 1.33 0.926 5 0.2 2mm 5mm 2.0 0.4 1.67 1.434

[0050] The specific values ​​of the weighting coefficients corresponding to the structural deformation degree, surface material thickness, and surface scale thickness are shown in Table 2 below. The allocation of the weighting coefficients is not fixed and can be adjusted based on the different storage materials.

[0051] Table 2 Examples of Weighting Coefficient Values

[0052] Application scenarios Weighting coefficient settings Design Logic Crude oil storage tanks (for high-viscosity media) Crude oil is prone to sedimentation, and the accumulated material has the greatest impact on radar wave attenuation. Chemical solvent tank (corrosive media) Solvents tend to crystallize and form scale, and the thickness of this scale directly affects radar wave penetration. Water storage tank (conventional medium) The risk of scale buildup in water-based media is low, but structural deformation (such as waveguide bending) has a more significant impact on measurement accuracy.

[0053] If both the single-parameter anomaly determination rule and the multi-parameter coupled anomaly determination rule result in an anomaly, then a level-one management measure is triggered.

[0054] As a preferred feasible embodiment, the primary management measures specifically include emergency shutdown maintenance and automated deep processing.

[0055] Specifically, the emergency shutdown maintenance includes immediately suspending the level gauge measurement function and triggering an audible and visual alarm.

[0056] The automated deep processing includes initiating multiple rounds of intensive cleaning and performing corrective processing using a deployed deformation correction robot.

[0057] In a specific example, the multi-round enhanced cleaning includes: Round 1, chemical solvent spraying (dissolving scale); Round 2, high-pressure water jet cutting (removing hard deposits); Round 3: ultrasonic cavitation (micropore cleaning).

[0058] The waveguide can be laser-calibrated and mechanically straightened by using a deployed deformation correction robot for correction.

[0059] If the result of the single-parameter anomaly determination rule is abnormal and the result of the multi-parameter coupled anomaly determination rule is normal, then a secondary management measure is triggered.

[0060] As a preferred feasible embodiment, the specific contents of the secondary management measures include: (1) when there is structural abnormality, applying reverse hydraulic correction force (deformation point positioning) or installing compensation bracket (to maintain mechanical balance); (2) when there is material accumulation abnormality, starting directional spray cleaning (cleaning only for the material accumulation area); (3) when there is scaling abnormality, activating the rotary scraper system (focusing only on the scaling area to perform scaling scraping operation) or injecting pH neutralizing agent (using chemical dissolution to remove scaling).

[0061] If the result of the multi-parameter coupling anomaly determination rule is abnormal and the result of the single-parameter anomaly determination rule is normal, then a level 3 management measure is triggered.

[0062] As a preferred feasible embodiment, the three-level management measures specifically include analyzing the root causes of anomalies based on multi-parameter composite anomaly coefficients, and obtaining three-level management measures based on the combination of management measures corresponding to the root causes of anomalies.

[0063] It should be noted that the root causes of the anomalies include any two or three of the following: structural anomalies, material accumulation anomalies, and scaling anomalies. Furthermore, management measures corresponding to structural anomalies have a higher priority than those corresponding to material accumulation anomalies, and vice versa.

[0064] It needs further explanation that the specific operation of analyzing the root cause of anomalies based on multi-parameter composite anomaly coefficients is as follows: if among the multi-parameter composite anomaly coefficients... If the value of an item is the largest, then its abnormal root cause is structural abnormality.

[0065] If the multi-parameter composite anomaly coefficient is among If the value of the item is the largest, then its abnormal root cause is abnormal material accumulation.

[0066] If the multi-parameter composite anomaly coefficient is among If the value of the item is the largest, then the root cause of its abnormality is abnormal scaling.

[0067] For example, if the root cause of the abnormality is "structural abnormality + material accumulation abnormality", the three-level management measures can be: "reverse hydraulic correction force to correct structural deformation + directional spray cleaning to remove material accumulation", first correct the structure to avoid material accumulation residue during cleaning, and then clean the material accumulation area in a targeted manner.

[0068] This invention assesses whether several key obstacles within the target storage tank have an abnormal impact on the radar level gauge monitoring process from multiple dimensions, including structural deformation, material accumulation thickness, and scale thickness. When an abnormal impact occurs, corresponding management measures are triggered. This breaks through the limitations of single-parameter analysis, helps reduce measurement errors caused by abnormalities in key obstacles, and ensures the stability of level monitoring.

[0069] S4. Detection of abnormal media characteristics: Based on the echo parameter data, the radar level gauge determines whether there is foam interference or steam interference in the media characteristics during level monitoring by using the media abnormality diagnosis rules. If an abnormality is found, corresponding maintenance measures are triggered.

[0070] As a preferred feasible embodiment, the specific content of the medium anomaly diagnosis rule includes: extracting the echo curve, echo quality index and dielectric constant of the radar level gauge in the target storage tank during level monitoring from the bad echo parameter data; if the echo curve has multiple (e.g. ≥2) continuously decreasing reflection peaks (e.g., foam attenuation peak following the main level peak), and the echo quality index decreases stepwise within a short period (e.g., decrease >15% in 10 minutes), and the dielectric constant is lower than the current standard dielectric constant, then the cause of the anomaly is recorded as the presence of foam interference.

[0071] It should be explained that the basis for determining the presence of foam interference based on the echo curve is as follows: foam is composed of a large number of gas-liquid mixed bubbles. When irradiated by radar waves, it will undergo multiple reflections and scatterings within the foam layer, forming a characteristic curve of "a main liquid level peak followed by multiple decreasing reflection peaks". This characteristic is significantly different from steam interference (wide-amplitude signal attenuation) and scaling interference (fixed reflection clutter), and can be used as the core basis for foam identification.

[0072] The basis for judging whether there is foam interference based on the Echo Quality Index (EQI) is as follows: EQI comprehensively reflects parameters such as signal-to-noise ratio and stability of the echo signal. During normal liquid level measurement, EQI fluctuations are small. The disordered gas-liquid interface of the foam layer will scatter radar waves, causing the signal energy to decay rapidly, which is manifested as a step-like decrease in EQI within a short period (10 minutes).

[0073] The basis for determining whether steam interference exists based on the dielectric constant is: the dielectric constant of the foam ( ≈1-3) is much lower than that of liquid media (such as water). ≈80, crude oil (≈2-4) Because the air content in the foam is high, the overall dielectric constant is close to that of air. If the dielectric constant is lower than the current standard dielectric constant, and is accompanied by abnormal echo curves and EQI, the influence of factors such as temperature changes on the dielectric constant can be ruled out, thus confirming the existence of foam interference.

[0074] If the overall signal of the echo curve is attenuated by a wide range (e.g., the main peak amplitude is less than 50% of the historical average), the echo quality index fluctuates at a low level (e.g., EQI is less than 30 and the standard deviation is less than 5 within 1 hour), and the dielectric constant oscillates at a high frequency (e.g., the fluctuation amplitude in 5 minutes is greater than 10% of the current standard dielectric constant), then the cause of the abnormality is recorded as the presence of vapor interference.

[0075] It should be explained that the basis for judging whether steam interference exists based on the echo curve is as follows: Steam is composed of a large number of tiny liquid droplets or gas molecules. When radar waves propagate in the steam layer, they will undergo strong scattering and absorption, resulting in a significant attenuation of the echo signal energy. If the amplitude of the main peak is less than 50% of the historical average, it reflects that the intensity of the liquid surface reflection signal is significantly reduced compared to normal operating conditions.

[0076] The basis for determining the presence of steam interference based on the Echo Quality Index (EQI) is as follows: EQI comprehensively characterizes the signal-to-noise ratio, stability, and discernibility of the echo signal. If the steam layer is in a stable generation state (such as uniform steam generated by continuous heating), the EQI will remain stable at a low level, which differs from the stepwise decrease seen in foam interference. For example, under normal operating conditions, the EQI is usually >60. When steam interference occurs, the signal energy is dispersed and noise increases, causing the EQI to remain below 30.

[0077] The basis for determining whether steam interference exists based on the dielectric constant is: the dielectric constant of the steam ( The dielectric constant (≈1.02-1.05) is much lower than that of liquid media. When the interface between steam and liquid changes frequently due to airflow disturbance, the dielectric constant in the radar wave propagation path will switch rapidly, which manifests as high-frequency oscillation.

[0078] As a preferred feasible embodiment, the maintenance measures corresponding to the foam interference include: (1) chemical defoaming, that is, automatically injecting defoamer through a nozzle; (2) ultrasonic breaking, that is, generating high-frequency mechanical vibration through a array of transducers to form microbubble cavitation nuclei in the foam liquid film, releasing shock waves when the cavitation nuclei break, and breaking the foam bubbles; (3) mechanical rotary cutting, that is, cutting into the foam layer through a rotary cutter, using shear force to destroy the bubble structure, and the built-in negative pressure pump of the cutter head synchronously sucks up the broken foam and transports it to the separation tank through a pipeline; (4) detecting the cause of foam formation and optimizing the corresponding process.

[0079] It should be noted that the specific operation of detecting the cause of foam and optimizing the corresponding process includes: using a PLC system to record the parameters of each process flow before the stored material enters the target storage tank, comparing them with the foam generation critical value of the corresponding process flow parameter, and if a certain process flow parameter is greater than the foam generation critical value of the corresponding process flow parameter, then the process flow parameter is recorded as the cause of foam.

[0080] In one specific example, the various process flows include, but are not limited to, a stirring process, a venting process, and a storage material input process. The parameter for the stirring process may be the stirring speed, the parameter for the venting process may be the gas flow rate, and the parameter for the storage material input process may be the input rate.

[0081] If the stirring speed is higher than the foam generation critical value of its corresponding parameter, then reduce the stirring speed and observe whether the foam subsides.

[0082] If the gas flow rate is higher than the foam generation critical value of its corresponding parameter, the gas flow rate is reduced and the foam is observed to dissipate.

[0083] If the input rate is higher than the foam generation threshold of its corresponding parameter, the input rate is reduced and the foam is observed to dissipate.

[0084] The maintenance measures corresponding to the steam interference include: (1) ventilation and cooling, that is, adjusting the air volume in real time according to the steam concentration by using a variable frequency fan (such as increasing the air volume from 500m³ / h to 800m³ / h when the steam concentration exceeds the threshold), and optimizing the ventilation duct in a directional manner (such as using a ring-shaped air supply structure) to ensure a uniform temperature field and avoid continuous steam generation in local high-temperature areas; (2) condensation recovery, that is, automatically adjusting the refrigerant flow rate through refrigerant circulation, or maintaining the condenser plate temperature at least 10°C below the steam dew point according to the temperature control system to ensure condensation efficiency; (3) pressure balance, that is, reducing the partial pressure of steam in the tank through the steam suction system to increase the boiling point of the liquid and suppress steam generation, or maintaining pressure stability by real-time feedback through a pressure sensor and linkage of the suction valve opening.

[0085] It should be noted that when dealing with volatile media (such as ethanol), the aforementioned pressure balance requires the suction system to be equipped with a condensation recovery device (such as a multi-stage condenser) to prevent media loss. When dealing with flammable and explosive media, the suction fan must be explosion-proof and equipped with nitrogen inerting protection.

[0086] This invention identifies whether foam or steam interference occurs when a radar level gauge monitors the liquid level through a triple verification method of echo curve, echo quality index, and dielectric constant. When interference occurs, corresponding maintenance measures are triggered, which improves the accuracy of interference cause identification, ensures the pertinence of maintenance measures, and avoids the decrease in radar level gauge measurement accuracy caused by abnormal medium characteristics.

[0087] S5. Level gauge calibration monitoring: Based on the dielectric constant of the current temperature of the material stored in the target tank after maintenance and management, the electromagnetic wave propagation speed of the radar level gauge in the target tank is corrected, and the level value currently monitored and output by the radar level gauge is read.

[0088] It should be noted that the specific method for matching the dielectric constant of the current temperature of the stored material in the target tank after maintenance and management is as follows: the current temperature of the stored material in the target tank is compared with the dielectric constant-temperature mapping curve to obtain the dielectric constant of the current temperature of the stored material in the target tank after maintenance and management.

[0089] As a preferred feasible embodiment, the specific process of correcting the electromagnetic wave propagation speed of the radar level gauge in the target storage tank includes: entering the parameter setting interface of the radar level gauge in the target storage tank, changing its dielectric constant to match the current temperature of the stored material in the target storage tank after maintenance and management, and confirming and saving the new dielectric constant according to the operation prompts of the radar level gauge in the target storage tank after the change is completed.

[0090] It should be noted that the operation methods for different models of radar level gauges vary. Refer to the corresponding instruction manual or user guide to familiarize yourself with its parameter setting interface and operating methods. This will allow you to access the parameter setting interface of the radar level gauge inside the target storage tank. For example, some level gauges require opening the gauge cover and pressing a specific key combination to enter the setting menu; network-connected level gauges can be remotely accessed and have their parameters set via relevant software.

[0091] Some radar level gauges require calibration after modifying their dielectric constant parameters, such as empty tank calibration, full tank calibration, or partial range calibration. You can also verify the measurement by comparing the gauge's reading with the actual liquid level to check if the measurement error is within acceptable limits. If a significant error persists, further investigation of other relevant parameter settings or a more comprehensive calibration procedure may be necessary.

[0092] Further calculations are made based on the standard formula for propagation speed and dielectric constant. The electromagnetic wave propagation speed of the radar level gauge inside the target storage tank was calculated. ,in To measure the dielectric constant of the material stored in the target storage tank again after maintenance and management, It is the speed of light in a vacuum.

[0093] A specific example is water ( Then, its value can be calculated according to the above formula. ,crude( Then, its value can be calculated according to the above formula. The speed difference is as high as 5.6 times, which will lead to serious measurement deviation if the algorithm is not corrected.

[0094] Example 2

[0095] See Figure 2 As shown, this invention provides a liquid level monitoring system based on a radar level gauge, with the following module distribution: a data detection module, a dielectric constant anomaly judgment module, an obstacle state anomaly detection module, a medium characteristic anomaly detection module, a level gauge calibration monitoring module, and a database. The modules are connected as follows: the data detection module is connected to the dielectric constant anomaly judgment module; the dielectric constant anomaly judgment module is connected to both the obstacle state anomaly detection module and the medium characteristic anomaly detection module; the obstacle state anomaly detection module and the medium characteristic anomaly detection module are connected to the level gauge calibration monitoring module; and the database is connected to the dielectric constant anomaly judgment module.

[0096] The data detection module collects the dielectric constant and current temperature of the material stored in the target tank according to a preset fixed detection cycle. It also simultaneously acquires the appearance status data of several key obstacles affecting radar wave propagation in the target tank, as well as the echo parameter data of the radar level gauge in the target tank during level monitoring.

[0097] The dielectric constant anomaly detection module determines whether the dielectric constant is abnormal based on the dielectric constant and the current temperature, according to the dielectric constant-temperature mapping curve. If abnormal, it simultaneously triggers the obstacle state anomaly detection process and the dielectric property anomaly detection process.

[0098] The obstacle status anomaly detection module determines whether the status of several key obstacles is abnormal based on the appearance status data and obstacle anomaly assessment rules. If an anomaly is detected, corresponding management measures are triggered.

[0099] The medium characteristic anomaly detection module, based on the echo parameter data, determines whether there is foam interference or steam interference in the medium characteristics of the radar level gauge during level monitoring through medium anomaly diagnosis rules. If an anomaly is found, corresponding maintenance measures are triggered.

[0100] The liquid level gauge calibration and monitoring module corrects the electromagnetic wave propagation speed of the radar liquid level gauge in the target storage tank based on the dielectric constant matched with the current temperature of the stored material in the target storage tank after maintenance and management, and reads the liquid level value currently monitored and output by the radar liquid level gauge.

[0101] The database stores dielectric constant-temperature mapping curves.

[0102] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, and all such modifications and additions should fall within the protection scope of the present invention.

Claims

1. A method of liquid level monitoring based on a radar level gauge, characterized by: The method comprises the following steps: S1, data detection: collecting the dielectric constant and the current temperature of the stored substance in the target storage tank according to a preset fixed detection period, synchronously acquiring the appearance state data of several key obstacles affecting radar wave propagation in the target storage tank and the echo parameter data of the radar liquid level meter in the target storage tank during liquid level monitoring; S2, dielectric constant anomaly judgment: judging whether the dielectric constant is abnormal according to a dielectric constant-temperature mapping curve based on the dielectric constant and the current temperature, and triggering an obstacle state anomaly detection process and a medium characteristic anomaly detection process simultaneously if the dielectric constant is abnormal; S3, obstacle state anomaly detection: judging whether the state of the several key obstacles is abnormal through an obstacle anomaly evaluation rule based on the appearance state data, and triggering corresponding management measures if the state of the several key obstacles is abnormal; S4, medium characteristic anomaly detection: judging whether there is foam interference or steam interference in the medium characteristic of the radar liquid level meter during liquid level monitoring through a medium anomaly diagnosis rule based on the echo parameter data, and triggering corresponding maintenance measures if there is abnormality; S5, liquid level meter calibration monitoring: matching the electromagnetic wave propagation speed of the radar liquid level meter in the target storage tank based on the dielectric constant of the stored substance in the target storage tank collected again after maintenance management, and reading the liquid level value currently monitored and output by the radar liquid level meter.

2. The liquid level monitoring method based on a radar level gauge according to claim 1, characterized in that: The specific process of judging whether the dielectric constant is abnormal comprises: comparing the current temperature of the stored substance in the target storage tank with the dielectric constant-temperature mapping curve, determining the dielectric constant of the stored substance in the target storage tank, recording it as the current standard dielectric constant of the stored substance in the target storage tank, and recording the dielectric constant of the stored substance in the target storage tank as abnormal if it is inconsistent with the current standard dielectric constant.

3. The liquid level monitoring method based on radar level gauge according to claim 1, characterized in that: The specific content of the obstacle anomaly evaluation rule comprises: extracting the structure deformation degree of the several key obstacles affecting radar wave propagation in the target storage tank and the surface area thickness and surface fouling thickness of each monitoring point from the appearance state data, inputting them into a single-parameter anomaly judgment rule and a multi-parameter coupling anomaly judgment rule to which the obstacle anomaly evaluation rule belongs respectively, and outputting the judgment results of the single-parameter anomaly judgment rule and the multi-parameter coupling anomaly judgment rule of the appearance state data; if the judgment results of the single-parameter anomaly judgment rule and the multi-parameter coupling anomaly judgment rule are both abnormal, triggering a first-level management measure; if the judgment result of the single-parameter anomaly judgment rule is abnormal and the judgment result of the multi-parameter coupling anomaly judgment rule is normal, triggering a second-level management measure; if the judgment result of the multi-parameter coupling anomaly judgment rule is abnormal and the judgment result of the single-parameter anomaly judgment rule is normal, triggering a third-level management measure.

4. The liquid level monitoring method based on the radar level gauge according to claim 3, characterized in that: The specific content of the single-parameter anomaly judgment rule comprises: The structure deformation degree of each key obstacle in the target storage tank is compared with a set structure deformation safety threshold, and if the structure deformation degree of the key obstacle is greater than the set structure deformation safety threshold, the state of the key obstacle is recorded as structure abnormality, and the state is recorded as the determination result of the single-parameter abnormality determination rule of the key obstacle.

5. The method of claim 3, wherein: The specific content of the multi-parameter coupling abnormality determination rule includes: According to the multi-parameter composite abnormality coefficient calculation formula, the multi-parameter composite abnormality coefficients of the key obstacles are obtained, which are compared with the preset multi-parameter composite abnormality coefficient threshold, and if the multi-parameter composite abnormality coefficient of a key obstacle is greater than or equal to the preset multi-parameter composite abnormality coefficient threshold, the state of the key obstacle is recorded as abnormality, and the state is recorded as the determination result of the multi-parameter coupling abnormality determination rule of the key obstacle, and the determination result of the multi-parameter coupling abnormality determination rule of the key obstacles is determined.

6. The method of claim 3, wherein: The specific content of the first-level management measure includes emergency shutdown maintenance and automatic deep treatment; The specific content of the second-level management measure includes: (1) for structure abnormality, applying a reverse hydraulic correction force or installing a compensation support; (2) for material accumulation abnormality, starting directional spray cleaning; (3) for scaling abnormality, activating a rotary scraper system or injecting a PH neutralizing agent; The specific content of the third-level management measure includes analyzing the root cause of abnormality based on the multi-parameter composite abnormality coefficient, and obtaining the third-level management measure based on the corresponding management measure combination of the root cause of abnormality.

7. The method of claim 1, wherein: The specific content of the medium abnormality diagnosis rule includes: The echo curve, echo quality index and dielectric constant of the radar liquid level meter in the target storage tank during liquid level monitoring are extracted from the echo parameter bad data, and if the echo curve has multiple consecutive decreasing reflection peaks, the echo quality index decreases in steps in a short period, and the dielectric constant is lower than the current standard dielectric constant, the abnormal reason is recorded as the existence of foam interference; If the overall signal width of the echo curve is attenuated, the echo quality index is continuously fluctuated, and the dielectric constant is high-frequency oscillated, the abnormal reason is recorded as the existence of steam interference.

8. The liquid level monitoring method based on a radar level gauge according to claim 7, characterized in that: The maintenance measures corresponding to the foam interference include: (1) chemical defoaming; (2) ultrasonic crushing; (3) mechanical rotary cutting; (4) detecting the cause of foam and optimizing the corresponding process; The maintenance measures corresponding to the steam interference include: (1) ventilation and cooling; (2) condensation recovery; (3) pressure balance.

9. The method of claim 1, wherein: The specific process of correcting the electromagnetic wave propagation speed of the radar liquid level meter in the target storage tank includes: Enter the parameter setting interface of the radar liquid level meter in the target storage tank, change the dielectric constant to the dielectric constant matched with the current temperature of the stored material in the target storage tank collected again after maintenance management, and after the change is completed, confirm and save the new dielectric constant according to the operation prompt of the radar liquid level meter in the target storage tank; Further according to the propagation speed and dielectric constant standard calculation formula The electromagnetic wave propagation speed of the radar liquid level meter in the target storage tank is calculated , wherein The dielectric constant of the stored substance in the target storage tank is collected again for maintenance management, is the speed of light in a vacuum.

10. A radar level gauge based liquid level monitoring system characterized in that: including: The data detection module collects the dielectric constant and the current temperature of the storage material in the target storage tank according to a preset fixed detection period, synchronously acquires appearance state data of a plurality of key obstacles in the target storage tank affecting radar wave propagation and echo parameter data of a radar liquid level meter in the target storage tank during liquid level monitoring; The dielectric constant anomaly judgment module judges whether the dielectric constant is abnormal according to a dielectric constant-temperature mapping curve based on the dielectric constant and the current temperature, and simultaneously triggers an obstacle state anomaly detection process and a medium characteristic anomaly detection process if the dielectric constant is abnormal; The obstacle state anomaly detection module judges whether the states of the plurality of key obstacles are abnormal through obstacle anomaly evaluation rules based on the appearance state data, and triggers corresponding management measures if the states of the plurality of key obstacles are abnormal; The medium characteristic anomaly detection module judges whether there is foam interference or steam interference in the medium characteristic of the radar liquid level meter during liquid level monitoring through medium anomaly diagnosis rules based on the echo parameter data, and triggers corresponding maintenance measures if there is abnormality; The liquid level meter calibration monitoring module matches the electromagnetic wave propagation speed of the radar liquid level meter in the target storage tank by using the dielectric constant of the storage material in the target storage tank collected again after maintenance management according to the current temperature, and reads the liquid level value currently monitored and output by the radar liquid level meter; The database stores the dielectric constant-temperature mapping curve.

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