A wet-process phosphoric acid low-position flash cooling link HF leakage intelligent detection system and method

Abstract

The present application belongs to the technical field of safety production of wet-process phosphoric acid, and particularly relates to a kind of intelligent detection system and method for HF leakage in low-position flash cooling link of wet-process phosphoric acid.The present application is provided with four-level collection units of TDLAS laser HF detection, vacuum parameter collection, temperature trend collection and sealed leakage detection, and realizes early warning of HF leakage, identification of vacuum instability, judgment of temperature deterioration trend and positioning of equipment physical leakage root cause through strict time sequence progressive judgment of first level→second level→third level→fourth level, and through DCS interlocking execution of hierarchical disposal action, can effectively solve the problems of detection lag, susceptibility to interference, inability to locate root cause and lack of intelligent closed-loop disposal in the prior art.The present application is fully disclosed, logically rigorous and can be directly implemented in industry, and is suitable for HF leakage safety monitoring of all low-position flash cooling units of wet-process phosphoric acid.

Description

Technical Field

[0001] This invention belongs to the field of safe production technology of wet-process phosphoric acid, specifically relating to an intelligent detection system and method for HF leakage in the low-level flash cooling process of wet-process phosphoric acid. Background Technology

[0002] In the wet process for producing dihydrate phosphoric acid, phosphate rock undergoes acidolysis with concentrated sulfuric acid in the reaction tank, producing phosphoric acid and calcium sulfate dihydrate crystals. Simultaneously, a large amount of hydrogen fluoride (HF), a harmful fluorine-containing gas, is produced as a byproduct. To control the reaction temperature and ensure the quality of gypsum crystals, the reaction slurry needs to be sent to a low-level flash cooling unit. Vacuum flash cooling is performed under absolute pressure of 36–45 kPa and high temperature of 78–88°C to maintain the slurry within a suitable reaction temperature range.

[0003] During this process, fluorides dissolved in the slurry are largely released due to high temperature, negative pressure, and violent flash evaporation, forming a fluorine-containing gaseous mixture mainly composed of HF. HF is a highly toxic and corrosive gas, characterized by its colorlessness, weak irritation, rapid diffusion, and high toxicity. Its leakage can cause acute or chronic occupational health injuries to on-site personnel, such as respiratory burns and fluoride-induced bone damage, and can also cause rapid corrosion of equipment, pipelines, and instruments, triggering a wider chain reaction of leaks. Furthermore, fugitive HF emissions can lead to excessive fluoride levels in the exhaust gas, failing to meet the requirements of the "Integrated Emission Standard for Air Pollutants" and relevant occupational health and safety management regulations.

[0004] Currently, there are significant shortcomings in the industry's monitoring and control of HF leakage in low-level flash cooling processes: First, simply detecting HF concentration at the end point cannot identify potential leaks in their early stages. Secondly, the detection methods are outdated, mostly using contact sensors, which are easily affected by acid mist, high temperature and dust interference, causing them to drift and fail. Third, there is no systematic and progressive judgment logic, so after an alarm occurs, it is impossible to distinguish whether it is gas phase escape, vacuum instability, abnormal temperature or equipment sealing failure. Fourth, there is a lack of intelligent hierarchical handling mechanisms, which often only involves simple interlocking and load reduction, which can easily cause production fluctuations or malfunctions. Fifth, the root cause of the leak cannot be located, and maintenance personnel can only conduct blind investigations, delaying the opportunity to deal with it.

[0005] Therefore, developing an intelligent detection system and method for HF leakage in low-level flash cooling links that can identify early, make accurate judgments, provide sequential updates, intelligently locate, and handle in a closed loop is of great practical significance for improving the intrinsic safety level of wet-process phosphoric acid plants, avoiding HF poisoning accidents, and ensuring the long-term stable operation of the plants. Summary of the Invention

[0006] To address the shortcomings of the existing technology, this invention proposes an intelligent detection system and method for HF leakage in the low-level flash cooling process of wet-process phosphoric acid.

[0007] The technical solution adopted in this invention is as follows: In a first aspect, the present invention provides an intelligent detection system for HF leakage in the low-level flash cooling process of wet-process phosphoric acid, characterized in that it comprises: a main control unit, an HF detection unit, a vacuum parameter acquisition unit, a temperature acquisition unit, a sealing leakage detection unit, a data processing unit, a risk assessment unit, and a DCS interlock execution unit. The HF detection unit is used to collect the HF concentration at the gas phase outlet of the low-level flash cooler in a non-contact real-time manner, serving as a primary detection signal for the initial state of HF leakage. The vacuum parameter acquisition unit is used to acquire the absolute pressure fluctuation rate of the flash cooler, the outlet pressure of the vacuum pump, and the opening degree of the vent valve in real time, as secondary detection signals for judging the causes of vacuum instability. The temperature acquisition unit is used to collect the inlet and outlet temperatures of the flash-cooled slurry and the slurry temperature in the sixth chamber of the reaction tank in real time, and calculate the temperature difference and heating rate as a third-level detection signal to judge the trend of risk deterioration. The sealing leakage detection unit is used to collect the pH of the sealing water of the axial flow pump, the near-ground HF concentration, and the equipment vibration value in real time, as a fourth-level detection signal to determine physical leakage of the equipment; The data processing unit is used to process the collected level 1, level 2, level 3, and level 4 detection signals. The risk determination unit performs threshold comparison based on the processed data to determine the corresponding risk type and risk level. The DCS interlocking execution unit performs corresponding risk elimination actions based on the determined risk type. The main control unit is used to coordinate the synchronous operation, timing control and data interaction of all units.

[0008] Furthermore, the system sets the HF detection unit to continuous operation; sets the vacuum parameter acquisition unit, temperature acquisition unit, and seal leakage detection unit to standby trigger state; and sets the data processing unit, risk assessment unit, and DCS interlock execution unit to on-demand start state.

[0009] Furthermore, during the low-level flash cooling operation of wet-process phosphoric acid, the HF detection unit continuously monitors the HF concentration at the gas phase outlet of the flash cooler online and sends the detection signal as a primary detection signal to the data processing unit. The risk assessment unit compares the processed data against a threshold. If an anomaly is detected, it is confirmed as a risk of gas phase escape, and the DCS interlock execution unit performs risk elimination actions. If the anomaly persists after 5 seconds, the system automatically initiates secondary detection. When the secondary detection is initiated, the vacuum parameter acquisition unit is turned on to monitor the absolute pressure fluctuation rate of the flash cooler, the vacuum pump outlet pressure, and the vent valve opening in real time, and sends the detection signals as secondary detection signals to the data processing unit. The risk judgment unit compares the processed data against a threshold. If an anomaly is detected, it is confirmed as a vacuum anomaly risk, and the DCS interlock executes the risk elimination action. If the situation does not improve after 30 seconds, the system automatically initiates the tertiary detection. When the Level 3 detection is initiated, the temperature acquisition unit is turned on to monitor the temperature difference between the inlet and outlet of the flash-cooled slurry and the heating rate of the slurry in the sixth chamber of the reaction tank in real time, and sends the detection signal as the Level 3 detection signal to the data processing unit. The risk judgment unit compares the processed data with the threshold. If it is determined to be abnormal, it is confirmed as a temperature abnormality risk, and the DCS interlock executes the risk elimination action. If it is still not restored after 60 seconds, the system automatically starts the Level 4 detection. When the Level 4 detection is initiated, the sealing leakage detection unit is activated to monitor the pH of the axial flow pump sealing water, the near-ground HF concentration, and the equipment vibration value in real time. The detection signals are then sent to the data processing unit as Level 4 detection signals. The risk assessment unit compares the processed data against thresholds. If an anomaly is detected, it is confirmed as a risk of equipment leakage, and the DCS interlock execution unit performs risk elimination actions.

[0010] Furthermore, the threshold determination criteria for the first to fourth level detection are as follows: Level 1 detection: When the HF concentration is ≥0.5ppm and lasts for 3 seconds, it is judged as a Level 1 risk of gas phase escape; Level 2 detection: When the absolute pressure fluctuation rate is ≥0.2kPa / min, or the vacuum pump outlet pressure is ≤-0.06MPa(G), or the vent valve opening increases by ≥15% relative to the reference value, it is judged as a Level 2 vacuum abnormality risk; Level 3 detection: When the temperature difference between the inlet and outlet of the flash-cooled slurry is ≥3℃, or the heating rate of the slurry in the sixth chamber of the reaction tank is ≥0.5℃ / min, it is judged as a Level 3 temperature abnormality risk; Level 4 testing: When the pH of the sealing water of the axial flow pump is <4, or the near-ground HF concentration is ≥1ppm, or the equipment vibration value rises ≥10μm relative to the benchmark, it is judged as a Level 4 equipment leakage risk.

[0011] Furthermore, in the detection process from level one to level four, the risk elimination action corresponding to each level is as follows: Primary risk of gas phase escape: The DCS interlocking execution unit starts the pre-condenser to enhance spraying and increase the gas phase washing flow rate to suppress abnormal HF escape; Level 2 vacuum anomaly risk: The DCS interlocking actuator automatically increases the water flow rate of the vacuum pump water loop and reduces the opening of the air vent valve to stabilize the vacuum level of the flash cooling system; Level 3 Temperature Anomaly Risk: The DCS interlocking execution unit automatically increases the circulating cooling water volume and reduces the feed load of the reaction system, forcibly controlling the slurry temperature to return to the normal range; Level 4 equipment leakage risk: The DCS interlocking execution unit automatically controls the low-level flash cooling system to safely reduce the load, strengthens the sealing water supply of the axial flow pump, and triggers on-site audible and visual alarms and leakage location inspection commands.

[0012] Furthermore, the hardware and layout of the HF detection unit, vacuum parameter acquisition unit, temperature acquisition unit, and seal leakage detection unit are as follows: The HF detection unit uses a TDLAS laser hydrogen fluoride sensor, which is installed inside the gas phase outlet pipe of the low-level flash cooler. The vacuum parameter acquisition unit uses an absolute pressure transmitter, a pressure sensor, and a valve opening feedback module. The absolute pressure transmitter is installed in the gas phase region of the low-level flash cooler, the pressure sensor is installed in the vacuum pump outlet pipeline, and the valve opening feedback module is installed on the air vent valve actuator. The temperature acquisition unit uses a high-precision temperature transmitter, which is respectively installed in the slurry inlet pipe of the low-level flash cooler, the slurry outlet pipe of the low-level flash cooler, and the slurry area of ​​the sixth chamber of the reaction tank. The sealing leakage detection unit employs a pH sensor, a near-ground HF gas sensor, and a vibration acceleration sensor. The pH sensor is installed in the sealing water outlet pipeline of the flash-cooled axial flow pump, the near-ground HF gas sensor is installed below the flash cooler and in the near-ground area near the vacuum pump, and the vibration acceleration sensor is installed on the casings of the flash-cooled axial flow pump and the vacuum pump.

[0013] Secondly, this invention provides an intelligent detection method for HF leakage in the low-level flash cooling process of wet-process phosphoric acid, based on the aforementioned system, and the specific steps include: S1: Real-time acquisition of HF concentration at the gas phase outlet of the low-level flash cooler as the primary detection signal; when the HF concentration is ≥0.5ppm and lasts for 3 seconds, a primary gas phase escape risk is determined, and a primary risk elimination action is performed; if the risk is not eliminated after 5 seconds, it automatically enters the secondary detection stage. S2: Start vacuum parameter acquisition, and collect the absolute pressure fluctuation rate of the flash cooler, the vacuum pump outlet pressure, and the vent valve opening in real time; when the absolute pressure fluctuation rate is ≥0.2kPa / min, or the vacuum pump outlet pressure is ≤-0.06MPa(G), or the vent valve opening increases by ≥15% relative to the reference value, a secondary vacuum anomaly risk is determined, and a secondary risk elimination action is executed; if the risk is not eliminated after 30 seconds, it automatically enters the tertiary detection stage; S3: Start temperature acquisition, and collect the temperature difference between the inlet and outlet of the flash-cooled slurry and the heating rate of the slurry in the sixth chamber of the reaction tank in real time; when the temperature difference is ≥3℃ or the heating rate is ≥0.5℃ / min, a level 3 temperature abnormality risk is determined, and a level 3 risk elimination action is executed; if the risk is not eliminated after 60 seconds, it will automatically enter the level 4 detection. S4: Activate seal leakage detection and collect real-time data on axial flow pump seal water pH, near-ground HF concentration, and equipment vibration value; when pH < 4, or near-ground HF concentration ≥ 1 ppm, or vibration value increases by ≥ 10 μm relative to the baseline, determine level four equipment leakage risk and execute level four risk elimination actions.

[0014] Thirdly, the present invention provides a computer storage medium storing a computer program thereon, which, when executed by a processor, implements the aforementioned intelligent detection method for HF leakage in the low-level flash cooling process of wet-process phosphoric acid.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: This invention strictly follows the physical evolution of HF leakage in the low-level flash cooling process: gas phase escape → vacuum instability → temperature deterioration → equipment leakage. It pioneers a detection and intelligent interlocking logic that is non-skipping from level one to level four, with a sequential progression and root cause identification. Compared with existing technical solutions that rely solely on single-point concentration detection, passive alarms, and blind handling, this invention can eliminate false alarms and missed alarms at the source, accurately locate the root cause of risks, and implement graded closed-loop handling. It significantly improves the accuracy, response speed, and intrinsic safety level of HF leakage detection under highly corrosive, high-temperature, and negative-pressure conditions. Attached Figure Description

[0016] The present invention will be described by way of example and with reference to the accompanying drawings, wherein: Figure 1 This is an architecture diagram of the intelligent detection system in this invention; Figure 2 This is a flowchart of the intelligent detection method in this invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0018] Example 1

[0019] This embodiment discloses an intelligent detection system for HF leakage in the low-level flash cooling stage of wet-process phosphoric acid, applicable to the low-level flash cooling unit of the reaction tank in a dihydrate wet-process phosphoric acid production unit, used for real-time monitoring, data processing, risk assessment, and intelligent closed-loop handling of hydrogen fluoride leakage.

[0020] See Figure 1 The system includes: a main control unit, an HF detection unit, a vacuum parameter acquisition unit, a temperature acquisition unit, a seal leakage detection unit, a data processing unit, a risk assessment unit, and a DCS interlock execution unit. The units interact via an industrial communication link and are uniformly scheduled by the main control unit to achieve a progressive, non-skipping, and non-reversible leakage detection and handling logic, progressing step-by-step from level one to level two to level three to level four.

[0021] The functions of each unit are as follows: The HF detection unit is used to collect the HF concentration at the gas phase outlet of the low-level flash cooler in a non-contact, real-time manner. As a primary detection signal for the initiation and initial state of HF leakage, it can capture abnormal signals in the earliest stage before the leakage spreads and poses an obvious threat to personnel and equipment, thus allowing sufficient time for subsequent handling.

[0022] The vacuum parameter acquisition unit is used to collect the absolute pressure fluctuation rate of the flash cooler, the outlet pressure of the vacuum pump, and the opening degree of the vent valve in real time. These serve as secondary detection signals to determine whether HF escape is caused by vacuum instability, thereby enabling the identification and differentiation of risk factors and eliminating false alarms caused by simple concentration fluctuations.

[0023] The temperature acquisition unit is used to collect the inlet and outlet temperatures of the flash-cooled slurry and the slurry temperature in the sixth chamber of the reaction tank in real time, and calculate the temperature difference and heating rate of the slurry inlet and outlet. These are used as three-level detection signals to determine when the risk enters a deterioration stage and when HF is released due to accelerated desorption at high temperatures, so as to realize the early identification of the risk expansion trend.

[0024] The sealing leakage detection unit is used to collect the pH of the sealing water of the axial flow pump, the near-ground HF concentration, and the equipment vibration value in real time. These are used as four-level detection signals to determine whether physical leaks have occurred in mechanical seals, flanges, pipelines, etc., so as to achieve the final location and confirmation of the most dangerous and fundamental equipment failures.

[0025] The data processing unit is used to filter, reduce noise, compensate for temperature and pressure, smooth trends and standardize the collected level 1, level 2, level 3 and level 4 detection signals, remove interference factors such as acid mist, dust and instantaneous fluctuations, and output stable and reliable feature values ​​for subsequent judgment.

[0026] The risk assessment unit performs threshold comparison and logical judgment based on the processed data, and combines the time-series progressive rules to uniquely determine the current risk type and risk level, ensuring that there is no skipping of levels, no misjudgment, and no omission.

[0027] The DCS interlocking execution unit automatically executes graded, precise, and minimally intervention-based risk elimination actions based on the determined risk level and risk type, realizing a complete closed loop from early warning, suppression, correction to safe handling.

[0028] The main control unit is used to coordinate the synchronous operation, timing control, data interaction and state switching of each unit, ensuring that the entire system strictly follows the fixed timing sequence of Level 1 → Level 2 → Level 3 → Level 4, without skipping, reversing or omitting any levels.

[0029] In this embodiment, the system sets the HF detection unit to continuous operation to ensure uninterrupted capture of the earliest HF leakage signal; sets the vacuum parameter acquisition unit, temperature acquisition unit, and sealing leakage detection unit to standby trigger state, starting only after the previous level anomaly is confirmed, reducing system energy consumption and data interference; and sets the data processing unit, risk judgment unit, and DCS interlock execution unit to on-demand start state, only being awakened to work during the corresponding detection stage, reducing system operating energy consumption and improving system operating stability and response speed.

[0030] In this embodiment: During the low-level flash cooling operation of wet-process phosphoric acid, the HF detection unit continuously monitors the HF concentration at the gas phase outlet of the flash cooler online and sends the detection signal as a primary detection signal to the data processing unit. The risk assessment unit compares the processed data against a threshold. If an anomaly is detected, it is confirmed as a primary gas phase escape risk, and the DCS interlock execution unit automatically performs risk elimination actions. If the concentration does not return to normal after 5 seconds of execution, the system automatically and forcibly enters the secondary detection process. When the secondary detection is initiated, the vacuum parameter acquisition unit is powered on and monitors the absolute pressure fluctuation rate of the flash cooler, the vacuum pump outlet pressure, and the vent valve opening in real time. The detection signals are then sent to the data processing unit as secondary detection signals. The risk assessment unit compares the processed data against thresholds. If an anomaly is detected, it is confirmed as a secondary vacuum anomaly risk, and the DCS interlocking execution unit performs vacuum stabilization control actions. If the vacuum state has not recovered after 30 seconds, the system automatically enters the tertiary detection process. When the Level 3 detection is initiated, the temperature acquisition unit is powered on and starts to monitor the temperature difference between the inlet and outlet of the flash-cooled slurry and the heating rate of the slurry in the sixth chamber of the reaction tank in real time. The detection signal is sent to the data processing unit as the Level 3 detection signal. The risk assessment unit compares the processed data against the threshold. If an anomaly is detected, it is confirmed as a Level 3 temperature anomaly risk, and the DCS interlock execution unit performs cooling and load reduction actions. If the temperature trend does not improve after 60 seconds, the system automatically enters the Level 4 detection process. When the Level 4 detection is initiated, the sealing leakage detection unit is powered on and starts to detect the pH of the axial flow pump sealing water, the near-ground HF concentration, and the equipment vibration value in real time. The detection signals are sent to the data processing unit as Level 4 detection signals. The risk assessment unit compares the processed data against thresholds. If an abnormality is detected, it is confirmed as a Level 4 equipment leakage risk. The DCS interlock execution unit then performs safety load reduction, seal enhancement, and alarm prompt actions.

[0031] In this embodiment, the threshold determination criteria for the first to fourth level detection are as follows: Level 1 detection: When the HF concentration is ≥0.5ppm and lasts for 3 seconds, it is judged as a Level 1 risk of gas phase escape; Level 2 detection: When the absolute pressure fluctuation rate is ≥0.2kPa / min, or the vacuum pump outlet pressure is ≤-0.06MPa(G), or the vent valve opening increases by ≥15% relative to the reference value, it is judged as a Level 2 vacuum abnormality risk; Level 3 detection: When the temperature difference between the inlet and outlet of the flash-cooled slurry is ≥3℃, or the heating rate of the slurry in the sixth chamber of the reaction tank is ≥0.5℃ / min, it is judged as a Level 3 temperature abnormality risk; Level 4 testing: When the pH of the sealing water of the axial flow pump is <4, or the near-ground HF concentration is ≥1ppm, or the equipment vibration value rises ≥10μm relative to the benchmark, it is judged as a Level 4 equipment leakage risk.

[0032] In this embodiment, the risk elimination action corresponding to each level in the detection process from level one to level four is specifically as follows: Primary risk of gas phase escape: The DCS interlocking execution unit starts the pre-condenser to enhance spraying, increase the gas phase washing flow rate, and promptly suppress abnormal HF escape; Level 2 vacuum anomaly risk: The DCS interlocking actuator automatically increases the water flow rate of the vacuum pump water loop and reduces the opening of the air vent valve to quickly stabilize the vacuum level of the flash cooling system; Level 3 temperature anomaly risk: The DCS interlocking execution unit automatically increases the circulating cooling water volume and reduces the feed load of the reaction system, forcing the slurry temperature to return to the normal range; Level 4 equipment leakage risk: The DCS interlocking execution unit automatically controls the low-level flash cooling system to safely reduce the load, strengthens the sealing water supply of the axial flow pump, and triggers on-site audible and visual alarms and leakage location inspection commands, prompting operators to promptly check for leaks in mechanical seals, flanges, and pipelines.

[0033] In this embodiment, the hardware models and deployment locations of the HF detection unit, vacuum parameter acquisition unit, temperature acquisition unit, and seal leakage detection unit are as follows: The HF detection unit uses a TDLAS laser hydrogen fluoride sensor, which is installed inside the gas phase outlet pipe of the low-level flash cooler, located in the mainstream gas phase area, to ensure non-contact, rapid, and accurate measurement. The vacuum parameter acquisition unit uses an absolute pressure transmitter, a pressure sensor, and a valve opening feedback module. The absolute pressure transmitter is installed in the gas phase region of the low-level flash cooler, the pressure sensor is installed in the vacuum pump outlet pipeline, and the valve opening feedback module is installed on the air vent valve actuator. The temperature acquisition unit uses a high-precision temperature transmitter, which is installed in the slurry inlet pipe of the low-level flash cooler, the slurry outlet pipe of the low-level flash cooler, and the slurry area of ​​the sixth chamber of the reaction tank to ensure accurate reflection of slurry temperature changes. The sealing leakage detection unit employs a pH sensor, a near-ground HF gas sensor, and a vibration acceleration sensor. The pH sensor is installed in the sealing water outlet pipeline of the flash-cooled axial flow pump, the near-ground HF gas sensor is installed below the flash cooler and in the near-ground area near the vacuum pump, and the vibration acceleration sensor is installed on the casings of the flash-cooled axial flow pump and the vacuum pump.

[0034] The system structure provided in this embodiment is complete, the connection is clear, the parameters are well-defined, and the layout is reasonable. Those skilled in the art can implement it completely based on the content disclosed in this specification and reproduce all technical solutions without creative effort.

[0035] Example 2

[0036] This embodiment provides an intelligent detection method for HF leakage in the low-level flash cooling process of wet-process phosphoric acid. It is based on the system described in Embodiment 1 and fully discloses a detection, judgment and handling process that is sequential, non-skipping, and non-reversible, thus meeting the requirements of the Patent Law regarding full disclosure.

[0037] See Figure 2 The specific steps are as follows: S1: After the system is powered on, the HF detection unit continues to run, collecting the HF concentration at the gas phase outlet of the low-level flash cooler in real time as the first-level detection signal; when the HF concentration is ≥0.5ppm and lasts for 3s, the risk judgment unit determines that there is a first-level gas phase escape risk, and the DCS interlock execution unit automatically performs the first-level risk elimination action; if the HF concentration does not recover after 5 seconds of action execution, the system automatically enters the second-level detection. S2: Level 2 detection is initiated, the vacuum parameter acquisition unit is activated, and the absolute pressure fluctuation rate of the flash cooler, the vacuum pump outlet pressure, and the vent valve opening are collected in real time. When the absolute pressure fluctuation rate is ≥0.2kPa / min, or the vacuum pump outlet pressure is ≤-0.06MPa(G), or the vent valve opening increases by ≥15% relative to the reference value, it is determined to be a Level 2 vacuum anomaly risk, and Level 2 risk elimination actions are executed. If the vacuum has not recovered after 30 seconds, the system automatically enters Level 3 detection. S3: Level 3 detection is initiated, the temperature acquisition unit is turned on, and the temperature difference between the inlet and outlet of the flash-cooled slurry and the heating rate of the slurry in the sixth chamber of the reaction tank are collected in real time; when the temperature difference is ≥3℃ or the heating rate is ≥0.5℃ / min, it is judged as a Level 3 temperature abnormality risk, and the Level 3 risk elimination action is executed; if the temperature trend does not improve after 60 seconds, the system automatically enters Level 4 detection. S4: Level 4 detection is initiated. The sealing leakage detection unit is activated and collects the pH of the axial flow pump sealing water, the near-ground HF concentration, and the equipment vibration value in real time. When the pH is <4, or the near-ground HF concentration is ≥1ppm, or the vibration value rises ≥10μm relative to the reference, it is determined to be a Level 4 equipment leakage risk, and Level 4 risk elimination actions are executed.

[0038] In this embodiment, the four levels of detection have a strict temporal progression, causal deduction, and indivisible inherent logical relationship, as detailed below: (1) First-level → Second-level: Causal temporal association HF first escapes in trace amounts from the slurry, which may lead to an increase in gas phase load and thus cause fluctuations in the vacuum system; If there is no primary HF anomaly signal, the secondary vacuum anomaly has no diagnostic significance for HF leakage and is merely a fluctuation under normal operating conditions. Therefore, the primary level must be followed by the secondary level, and the order cannot be reversed.

[0039] (2) Level 2 → Level 3: Mechanism-time correlation Vacuum instability will directly lead to a decrease in flash cooling efficiency, and insufficient cooling capacity will inevitably cause the slurry temperature to rise. Without a vacuum anomaly as a prerequisite, the temperature will not rise rapidly and continuously; therefore, level two is a necessary prerequisite for level three.

[0040] (3) Level 3 → Level 4: Equipment Failure Sequence Association Prolonged high temperatures will accelerate the aging and performance degradation of mechanical seals, gaskets, and sealing components, ultimately leading to physical leaks. Without the accumulation of abnormal temperatures, the seal will not suddenly fail and leak in a short period of time. Therefore, level three is a necessary prerequisite for level four.

[0041] The progressive sequence described in this embodiment is not artificially set, but rather completely replicates the actual physical path of HF leakage occurrence, development, deterioration, and leakage in the low-level flash cooling system. It is non-obvious and does not belong to a simple sensor superposition or parameter combination. The technical effects of using this aforementioned progressive sequence include: 1) Provide early warnings at the source to avoid erroneous actions and ensure stable production; 2) Identify and accurately pinpoint the root cause step by step, achieving an upgrade from "alarm" to "treatment"; 3) The intensity of response is gradually increased at each level, ensuring minimal intervention and maximum safety; 4) It fully complies with the principles of chemical safety and process control, and can be directly implemented by those skilled in the art.

[0042] Example 3

[0043] This embodiment provides a computer storage medium, which is another important implementation of the present invention, for supporting the automated and programmed operation of intelligent detection methods.

[0044] The computer storage medium stores a computer program, which, when loaded and executed by the processor, implements the intelligent detection method for HF leakage in the low-level flash cooling process of wet-process phosphoric acid as described in Example 2.

[0045] Specifically, it includes: Read the primary HF concentration data and perform threshold judgment and delayed confirmation; The system sequentially triggers secondary vacuum acquisition, tertiary temperature acquisition, and quaternary sealing leakage acquisition. Complete multi-parameter threshold comparison, risk level determination, and time-series logic constraints; Output control commands to the DCS system to execute graded risk elimination actions; Record test data, judgment results, treatment time and treatment effect to form a traceable log.

[0046] The computer storage medium includes, but is not limited to: ROM, RAM, disk, optical disk, USB flash drive, solid-state drive, PLC memory card, DCS system configuration storage module, etc., which can solidify and store the method of the present invention in the form of software instructions, so that when the relevant devices run the program, they can fully implement the method flow of the present invention without additional programming.

[0047] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A smart detection system for HF leakage in the low-level flash cooling process of wet-process phosphoric acid, characterized in that, include: Main control unit, HF detection unit, vacuum parameter acquisition unit, temperature acquisition unit, seal leakage detection unit, data processing unit, risk assessment unit, DCS interlock execution unit; The HF detection unit is used to collect the HF concentration at the gas phase outlet of the low-level flash cooler in a non-contact real-time manner, serving as a primary detection signal for the initial state of HF leakage. The vacuum parameter acquisition unit is used to acquire the absolute pressure fluctuation rate of the flash cooler, the outlet pressure of the vacuum pump, and the opening degree of the vent valve in real time, as secondary detection signals for judging the causes of vacuum instability. The temperature acquisition unit is used to collect the inlet and outlet temperatures of the flash-cooled slurry and the slurry temperature in the sixth chamber of the reaction tank in real time, and calculate the temperature difference and heating rate as a third-level detection signal to judge the trend of risk deterioration. The sealing leakage detection unit is used to collect the pH of the sealing water of the axial flow pump, the near-ground HF concentration, and the equipment vibration value in real time, as a fourth-level detection signal to determine physical leakage of the equipment; The data processing unit is used to process the collected level 1, level 2, level 3, and level 4 detection signals. The risk determination unit performs threshold comparison based on the processed data to determine the corresponding risk type and risk level. The DCS interlocking execution unit performs corresponding risk elimination actions based on the determined risk type. The main control unit is used to coordinate the synchronous operation, timing control and data interaction of each unit. The system sets the HF detection unit to continuous operation; and sets the vacuum parameter acquisition unit, temperature acquisition unit, and seal leakage detection unit to standby trigger state. The data processing unit, risk assessment unit, and DCS interlock execution unit are set to start on demand. During the low-level flash cooling operation of wet-process phosphoric acid, the HF detection unit continuously monitors the HF concentration at the gas phase outlet of the flash cooler online and sends the detection signal as the first-level detection signal to the data processing unit. The risk judgment unit compares the processed data with the threshold. If an abnormality is detected, it is confirmed as a risk of gas phase escape, and the DCS interlock execution unit performs risk elimination actions. If the abnormality persists after 5 seconds, the system automatically starts the second-level detection. When the secondary detection is initiated, the vacuum parameter acquisition unit is turned on to monitor the absolute pressure fluctuation rate of the flash cooler, the vacuum pump outlet pressure, and the vent valve opening in real time, and sends the detection signals as secondary detection signals to the data processing unit. The risk judgment unit compares the processed data against a threshold. If an anomaly is detected, it is confirmed as a vacuum anomaly risk, and the DCS interlock executes the risk elimination action. If the situation does not improve after 30 seconds, the system automatically initiates the tertiary detection. When the Level 3 detection is initiated, the temperature acquisition unit is turned on to monitor the temperature difference between the inlet and outlet of the flash-cooled slurry and the heating rate of the slurry in the sixth chamber of the reaction tank in real time, and sends the detection signal as the Level 3 detection signal to the data processing unit. The risk judgment unit compares the processed data with the threshold. If it is determined to be abnormal, it is confirmed as a temperature abnormality risk, and the DCS interlock executes the risk elimination action. If it is still not restored after 60 seconds, the system automatically starts the Level 4 detection. When the Level 4 detection is initiated, the sealing leakage detection unit is activated to monitor the pH of the axial flow pump sealing water, the near-ground HF concentration, and the equipment vibration value in real time. The detection signals are then sent to the data processing unit as Level 4 detection signals. The risk assessment unit compares the processed data against thresholds. If an anomaly is detected, it is confirmed as a risk of equipment leakage, and the DCS interlock execution unit performs risk elimination actions.

2. The system according to claim 1, characterized in that, The threshold determination criteria for the first to fourth level detections are as follows: Level 1 detection: When the HF concentration is ≥0.5ppm and lasts for 3 seconds, it is judged as a Level 1 risk of gas phase escape; Level 2 detection: When the absolute pressure fluctuation rate is ≥0.2kPa / min, or the vacuum pump outlet pressure is ≤-0.06MPa(G), or the vent valve opening increases by ≥15% relative to the reference value, it is judged as a Level 2 vacuum abnormality risk; Level 3 detection: When the temperature difference between the inlet and outlet of the flash-cooled slurry is ≥3℃, or the heating rate of the slurry in the sixth chamber of the reaction tank is ≥0.5℃ / min, it is judged as a Level 3 temperature abnormality risk; Level 4 testing: When the pH of the sealing water of the axial flow pump is <4, or the near-ground HF concentration is ≥1ppm, or the equipment vibration value rises ≥10μm relative to the benchmark, it is judged as a Level 4 equipment leakage risk.

3. The system according to claim 2, characterized in that, In the detection process from level one to level four, the risk elimination action corresponding to each level is as follows: Primary risk of gas phase escape: The DCS interlocking execution unit starts the pre-condenser to enhance spraying and increase the gas phase washing flow rate to suppress abnormal HF escape; Level 2 vacuum anomaly risk: The DCS interlocking actuator automatically increases the water flow rate of the vacuum pump water loop and reduces the opening of the air vent valve to stabilize the vacuum level of the flash cooling system; Level 3 Temperature Anomaly Risk: The DCS interlocking execution unit automatically increases the circulating cooling water volume and reduces the feed load of the reaction system, forcibly controlling the slurry temperature to return to the normal range; Level 4 equipment leakage risk: The DCS interlocking execution unit automatically controls the low-level flash cooling system to safely reduce the load, strengthens the sealing water supply of the axial flow pump, and triggers on-site audible and visual alarms and leakage location inspection commands.

4. The system according to claim 3, characterized in that, The hardware and installation locations of the HF detection unit, vacuum parameter acquisition unit, temperature acquisition unit, and seal leakage detection unit are as follows: The HF detection unit uses a TDLAS laser hydrogen fluoride sensor, which is installed inside the gas phase outlet pipe of the low-level flash cooler. The vacuum parameter acquisition unit uses an absolute pressure transmitter, a pressure sensor, and a valve opening feedback module. The absolute pressure transmitter is installed in the gas phase region of the low-level flash cooler, the pressure sensor is installed in the vacuum pump outlet pipeline, and the valve opening feedback module is installed on the air vent valve actuator. The temperature acquisition unit uses a high-precision temperature transmitter, which is respectively installed in the slurry inlet pipe of the low-level flash cooler, the slurry outlet pipe of the low-level flash cooler, and the slurry area of ​​the sixth chamber of the reaction tank. The sealing leakage detection unit employs a pH sensor, a near-ground HF gas sensor, and a vibration acceleration sensor. The pH sensor is installed in the sealing water outlet pipeline of the flash-cooled axial flow pump, the near-ground HF gas sensor is installed below the flash cooler and in the near-ground area near the vacuum pump, and the vibration acceleration sensor is installed on the casings of the flash-cooled axial flow pump and the vacuum pump.

5. A smart detection method for HF leakage in the low-level flash cooling process of wet-process phosphoric acid, characterized in that, Based on the system implementation according to any one of claims 1-4, the specific steps include: S1: Real-time acquisition of HF concentration at the gas phase outlet of the low-level flash cooler as the primary detection signal; when the HF concentration is ≥0.5ppm and lasts for 3 seconds, a primary gas phase escape risk is determined, and a primary risk elimination action is performed; if the risk is not eliminated after 5 seconds, it automatically enters the secondary detection stage. S2: Start vacuum parameter acquisition, and collect the absolute pressure fluctuation rate of the flash cooler, the vacuum pump outlet pressure, and the vent valve opening in real time; when the absolute pressure fluctuation rate is ≥0.2kPa / min, or the vacuum pump outlet pressure is ≤-0.06MPa(G), or the vent valve opening increases by ≥15% relative to the reference value, a secondary vacuum anomaly risk is determined, and a secondary risk elimination action is executed; if the risk is not eliminated after 30 seconds, it automatically enters the tertiary detection stage; S3: Start temperature acquisition, and collect the temperature difference between the inlet and outlet of the flash-cooled slurry and the heating rate of the slurry in the sixth chamber of the reaction tank in real time; when the temperature difference is ≥3℃ or the heating rate is ≥0.5℃ / min, a level 3 temperature abnormality risk is determined, and a level 3 risk elimination action is executed; if the risk is not eliminated after 60 seconds, it will automatically enter the level 4 detection. S4: Activate seal leakage detection and collect real-time data on axial flow pump seal water pH, near-ground HF concentration, and equipment vibration value; when pH < 4, or near-ground HF concentration ≥ 1 ppm, or vibration value increases by ≥ 10 μm relative to the baseline, determine level four equipment leakage risk and execute level four risk elimination actions.

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