Safety monitoring system and method for flow chemical experiment process

Abstract

The invention discloses a flow chemical experiment process safety monitoring system and method, and the system comprises a plurality of sensors which collect the safety related parameters of a flow chemical experiment process in real time, and transmit the safety related parameters to a data processing unit; the data processing unit preprocesses the sensor data to form standardized data; and the logic judgment unit performs program exception judgment on the standardized data, transmits a judgment result to the execution module, continuously judges that the experimental program can be recovered according to the execution condition of the experimental program if the program is exceptional, and enters emergency measures and / or manual intervention if the experimental program cannot be recovered. The method has the technical effects that more and more comprehensive safety related parameter supervision is provided for the safety of the experiment process; sensor data are automatically processed in real time, abnormity is recognized, and a manual judgment scheme is abandoned; global joint control is realized with other related equipment or systems; the emergency operation process is automatically executed; and digital full-closed-loop management of event records is realized.

Description

Technical Field

[0001] The invention relates to the field of chemistry, in particular to a flow chemistry experiment process safety monitoring system. Background Art

[0002] Flow Chemistry, also known as continuous flow chemistry, is a process of conducting chemical reactions in a continuously flowing fluid. Different reactants are pumped into a mixer and flow to a pipe, pipeline or microstructured reactor where the reaction conditions such as temperature and pressure are controlled until the reaction is completed. In terms of experimental process safety, flow chemistry technology (i.e., flow technology) has several significant key advantages compared to traditional standard batch chemical methods (i.e., Batch technology):

[0003] 1. Intrinsically safe. Due to the small amount of reagents in the reactor and good heat and mass transfer, the heat and gas release are relatively mild.

[0004] 2. Reaction conditions can be precisely controlled, especially for high temperature and high pressure.

[0005] 3. It can provide reaction conditions that cannot be achieved or are difficult to operate and scale up in intermittent reactors, such as photochemistry, ultra-high temperature, electrochemistry, microwave, ultrasound, etc.

[0006] Compared with batch chemical reactions, flow chemistry has made safety improvements in the reaction process technology, but flow chemistry itself still has certain safety risks in experimental operations, such as solid blockage leading to tube burst, peristaltic pump head tube aging and tube burst, plunger pump seal failure and leakage, hydrogen leakage, ultraviolet light leakage, metal reagents coming into contact with oxygen and burning, reagents burning in the column oven and even flash explosion, etc.

[0007] At present, the operation of flow chemistry experiments is mainly based on chemists assembling experimental devices in pieces, manually setting control equipment, and observing experimental phenomena with the naked eye. On the one hand, the supervision of changes in reaction process parameters is not comprehensive, continuous, and in-depth enough. On the other hand, if an abnormality occurs, it is difficult to make a quick judgment and accurately and completely perform emergency operations. In addition, due to the strong reliance on human observation, experience, and operation, different people, or even the same person at different times, have uneven work levels and states. Even if individual equipment has an alarm shutdown function, it is limited to the individual and cannot be linked with other instruments and equipment, or even the entire laboratory environment, water, electricity, and other public works, and cannot maximize safety assurance.

[0008] Therefore, it is necessary to automatically monitor various parameters and situations based on the five basic factors of "man-machine-method-material-environment" of the experimental process, to make early warning judgments, to automatically perform standard interlocking operations on related equipment when abnormalities occur, and to make reminders and records. The existing technology has the following defects in the safety monitoring of flow chemistry experimental processes that need to be improved:

[0009] 1) Few safety supervision parameters:

[0010] In addition to the core process parameter of chemical reactions - temperature, FLOW technology also uses process parameters such as actual flow rate, temperature at different positions in the system flow, and pressure, which are critical to the safe conduct of the reaction because the reagents flow in the pipeline. At present, laboratories still mainly use traditional detection methods such as glass thermometers and mechanical pressure gauges. If special reaction conditions such as photoreactions and electrochemical reactions are involved, core reaction conditions such as light intensity (which may change due to light attenuation caused by the thermal effect of LED lamp columns) and current (which may change due to the deposition of reactants on the surface of the electrode column, causing changes in current intensity) are not monitored.

[0011] 2) Out-of-control reactions rely on human judgment:

[0012] Currently, chemists make comprehensive judgments based on instrument measurements and visual observations, relying on work experience, which can easily lead to misjudgments or even missed judgments. As a result, even if emergency operations are performed immediately, accidents cannot be completely stopped. In addition, chemists are required to stand guard in front of the fume hood for a long time, which is time-consuming and laborious.

[0013] 3) Unable to control with other related equipment or systems:

[0014] Even if existing equipment has an over-limit alarm shutdown function, it can only shut down itself and is generally unable to transmit alarm signals to other devices or systems, let alone coordinate emergency actions.

[0015] 4) Lack of automated emergency response measures:

[0016] At present, emergency operations after discovering an abnormality are completely performed manually by chemists, which requires the parties to be familiar with the complete and standard operating procedures, master the control of each relevant instrument, and have a strong psychological quality to remain calm in the face of danger. In addition, people and dangerous sources are in the same environment, which poses a considerable safety risk.

[0017] 5) Event recording relies on manual work:

[0018] The recording of relevant data relies on manual work, which often leads to omissions or errors due to various subjective and objective factors, affecting the true traceability of events. If the anomalies are not handled thoroughly enough, it will pose a hidden danger. Summary of the invention

[0019] A series of simplified concepts are introduced in the Summary of the Invention, which are all simplifications of the prior art in the field, and will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention of the present invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0020] The technical problem to be solved by the present invention is to provide a system and method for safely monitoring a flow chemistry experiment process according to safety-related parameters and parameter change trends of the real-time flow chemistry experiment process.

[0021] In order to solve the above technical problems, the present invention provides a flow chemistry experiment process safety monitoring system, comprising:

[0022] Multiple sensors are arranged on the monitored experimental device, respectively, for real-time acquisition of safety-related parameters of the flow chemistry experiment process and sending them to the data processing unit; each sensor is arranged at a corresponding position of the flow chemistry experimental device according to its acquisition parameters; the operating process information of the monitored experimental device, such as temperature, pressure, flow, etc., acquired by the sensor in real time, is converted into electrical signals and transmitted to the data processing unit;

[0023] A data processing unit receives sensor data, pre-processes the sensor data to form standardized data and sends it to the logic judgment unit; the pre-processing includes removing impurities, filtering, and dimension unification;

[0024] The logic judgment unit performs program anomaly judgment on the standardized data and transmits the judgment result to the execution module. If the program is normal, the process ends. If the program is abnormal, it continues to judge whether the experimental program can be restored based on the execution status of the experimental program. If the experimental program cannot be restored, emergency measures and / or manual intervention are implemented.

[0025] The execution module performs emergency operations on the monitored experimental device, such as stopping the reaction device, stopping the gas source, increasing the exhaust, etc. if the H2 pipeline leaks; accordingly, after receiving the action execution information from the safety monitoring system, the process control system will also drive the execution module to perform other corresponding operations, such as activating the backup gas source to ensure the continued operation of other experimental equipment, etc.

[0026] Preferably, the flow chemistry experiment process safety monitoring system is further improved, and judging whether the experiment process can be restored includes:

[0027] If the program abnormality is caused by normal operation, then after the first delay, it is determined again whether the measured variable causing the program abnormality has returned to normal; if it is not caused by normal operation, emergency measures are taken;

[0028] If the system returns to normal after the first delay, the monitoring ends; if the system does not return to normal after the first delay, it is judged that a safety anomaly has occurred and emergency measures are taken;

[0029] Enter the emergency measures and after the second delay, determine whether the measured variable that caused the program abnormality has returned to normal; if it has returned to normal, end the monitoring;

[0030] If it does not return to normal, human intervention is required.

[0031] Preferably, the flow chemistry experiment process safety monitoring system is further improved, and the logic judgment unit also sends the original signal and standardized data of the safety-related parameters to the historical database of the central control system for storage, and also sends the judgment result to the process control system. The process control system executes corresponding preset operations according to the judgment result of the logic judgment unit.

[0032] The original signal, standardized data and execution instructions are transmitted to the historical database in real time in the form of structured variables for storage. The database is redundantly backed up and has permission management. It can record the login and browsing of the operating account for future reference.

[0033] Preferably, the flow chemistry experiment process safety monitoring system is further improved, and the safety-related parameters include: flow rate, temperature, pressure, oxygen concentration, liquid leakage detection, combustible gas detection, toxic and harmful gas detection, ventilation equipment detection and personnel detection.

[0034] Preferably, the flow chemistry experiment process safety monitoring system is further improved, and the program abnormality judgment includes:

[0035] Determine whether to trigger a real-time value abnormal alarm based on the standardized data. If the real-time value abnormal alarm is triggered, further determine whether the duration of the real-time value abnormal alarm is greater than or equal to the time threshold t1;

[0036] Calculate parameter change trends based on standardized data;

[0037] If the parameter change trend abnormal alarm is triggered and the duration is greater than or equal to the time threshold t1, it is judged as a program abnormality.

[0038] Preferably, the flow chemistry experiment process safety monitoring system is further improved, and the parameter change trend calculation includes:

[0039] The changing trend is

[0040]

[0041] The real-time sensor collection value is V0, t calculates the sampling interval, and the historical values ​​of the previous moments are V1, V2, V3, V4, V5…V t ;

[0042] The rate of change before time m is k m ,m is the filtering parameter, dimensionless.

[0043] Preferably, the flow chemistry experiment process safety monitoring system is further improved to determine whether to trigger a real-time value abnormal alarm by comparing the real-time value with the designed threshold value;

[0044] The designed threshold is a multi-level threshold, each level of the threshold corresponds to a different alarm level, and each alarm level triggers a corresponding preset operation.

[0045] Preferably, the flow chemistry experiment process safety monitoring system is further improved, and the emergency measures include:

[0046] Divide the hazard levels and assign different operations to each hazard level;

[0047] Query to obtain the current hazard level and perform preset operations based on the current hazard level.

[0048] In order to solve the above technical problems, the present invention provides a flow chemistry experiment process safety monitoring method, comprising the following steps:

[0049] Real-time collection of safety-related parameters during flow chemistry experiments;

[0050] Preprocess safety-related parameters to form standardized data;

[0051] The program abnormality is judged on the standardized data. If the program is normal, the process is terminated. If the program is abnormal, it is continued to determine whether the experimental program can be restored based on the execution status of the experimental program. If the experimental program cannot be restored, emergency measures and / or manual intervention are implemented.

[0052] Preferably, the flow chemistry experiment process safety monitoring method is further improved, and judging whether the experiment process can be restored includes:

[0053] If the program abnormality is caused by normal operation, then after the first delay, it is determined again whether the measured variable causing the program abnormality has returned to normal; if it is not caused by normal operation, emergency measures are taken;

[0054] If the system returns to normal after the first delay, the monitoring ends; if the system does not return to normal after the first delay, it is judged that a safety anomaly has occurred and emergency measures are taken;

[0055] Enter the emergency measures and after the second delay, determine whether the measured variable that caused the program abnormality has returned to normal; if it has returned to normal, end the monitoring;

[0056] If it does not return to normal, human intervention is required.

[0057] Preferably, the flow chemistry experiment process safety monitoring method is further improved, and the safety-related parameters include: flow rate, temperature, pressure, oxygen concentration, leakage detection, combustible gas detection, toxic and harmful gas detection, ventilation equipment detection and personnel detection.

[0058] Preferably, the flow chemistry experiment process safety monitoring method is further improved, and the process abnormality judgment includes:

[0059] Determine whether to trigger a real-time value abnormal alarm based on the standardized data. If the real-time value abnormal alarm is triggered, further determine whether the duration of the real-time value abnormal alarm is greater than or equal to the time threshold t1;

[0060] Calculate parameter change trends based on standardized data;

[0061] If the parameter change trend abnormal alarm is triggered and the duration is greater than or equal to the time threshold t1, it is judged as a program abnormality.

[0062] Preferably, the flow chemistry experiment process safety monitoring method is further improved, and the parameter change trend calculation includes:

[0063] The changing trend is

[0064]

[0065] The real-time sensor collection value is V0, t calculates the sampling interval, and the historical values ​​of the previous moments are V1, V2, V3, V4, V5…V t ;

[0066] The rate of change before time m is k m ,m is the filtering parameter, dimensionless.

[0067] Preferably, the flow chemistry experiment process safety monitoring method is further improved, and whether to trigger a real-time value abnormal alarm is determined by comparing the real-time value with the designed threshold value;

[0068] The designed threshold is a multi-level threshold, each level of the threshold corresponds to a different alarm level, and each alarm level triggers a corresponding preset operation.

[0069] Preferably, the flow chemistry experiment process safety monitoring method is further improved, and the emergency measures include:

[0070] Divide the hazard levels and assign different operations to each hazard level;

[0071] Query to obtain the current hazard level and perform preset operations based on the current hazard level.

[0072] In view of the defects of the prior art, the present invention can achieve the following technical effects:

[0073] 1) Provide more comprehensive safety-related parameter supervision for the safety of the experimental process;

[0074] Traditional laboratory safety monitoring is nothing more than monitoring of flammable gases, carbon monoxide and other toxic and harmful gases, smoke and fire. However, there is a lack of information acquisition on the essence of potential safety hazards, that is, whether the chemical reaction is reliable and stable. The mobile chemical laboratory using this patent can monitor the state of the chemical reaction itself in real time, including temperature, pressure, flow rate, light intensity, current, etc. When these parameters deviate, timely reminders and response standard processing work are made to fundamentally ensure the safety of personnel and equipment during the experiment.

[0075] 2) Automatically process sensor data in real time and identify anomalies, eliminating manual judgment solutions;

[0076] Through computer programming technology, sensor data related to safety-related reactions can be obtained in real time, and standardized data processing algorithms can be used for supervision and analysis. The evaluation criteria are unified and do not rely on the work experience of the inspectors, thus avoiding misjudgments or even missed judgments. The response speed is fast, and the abnormality is responded to immediately, so that the impact of the accident is minimized in the early stage. It can also achieve 7*24h uninterrupted safety supervision, effectively reducing the workload of personnel.

[0077] 3) Realize global joint control with other related equipment or systems;

[0078] As an important part of the laboratory safety system, in addition to joint control operations on chemical reaction devices, including process control systems and central control systems, such as shutdown, emergency emptying, flushing, cooling, etc., it can also work in conjunction with other supporting devices. For example, in the hydrogenation reaction, if the gas flow controller is abnormal and causes hydrogen to overflow, after detecting the fault, in addition to shutting down the reaction system itself, the hydrogen gas source is cut off and the exhaust of the fume hood is increased to strengthen safety processing.

[0079] 4) Automated execution of emergency operation procedures;

[0080] The computer program sets standard processing procedures for different devices and different events. Once the threshold is triggered, the standardization is automatically executed. On the one hand, there is no need for on-site personnel to handle it, avoiding secondary injuries; on the other hand, the standardized procedures ensure the timeliness, standardization and effectiveness of the action execution, and eliminate safety hazards as quickly, accurately and ruthlessly as possible.

[0081] 5) Realize digital closed-loop management of event records;

[0082] Relevant accident data is digitized and recorded truthfully to facilitate tracing and review. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] The drawings of the present invention are intended to illustrate the general characteristics of the methods, structures and / or materials used in specific exemplary embodiments of the present invention, and to supplement the description in the specification. However, the drawings of the present invention are schematic diagrams not drawn to scale, and thus may not accurately reflect the precise structure or performance characteristics of any given embodiment, and the drawings of the present invention should not be interpreted as limiting or restricting the range of values ​​or properties covered by the exemplary embodiments of the present invention. The present invention is further described in detail below in conjunction with the drawings and specific embodiments:

[0084] Figure 1 It is a schematic diagram of the system architecture of the present invention.

[0085] Figure 2 It is a schematic diagram of the abnormality judgment flow of the measured variable of the present invention.

[0086] Figure 3 It is a schematic diagram of the program abnormality judgment flow of the present invention.

[0087] Figure 4 This is an example of a hydrogen reaction. DETAILED DESCRIPTION

[0088] The following is an explanation of the embodiments of the present invention by specific specific embodiments, and those skilled in the art can fully understand other advantages and technical effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, and various modifications or changes can be made without deviating from the general design concept of the invention. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. The following exemplary embodiments of the present invention can be implemented in a variety of different forms and should not be interpreted as being limited to the specific embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary specific embodiments to those skilled in the art. It should be understood that when an element is referred to as "connected" or "coupled" to another element, the element can be directly connected or coupled to another element, or there can be an intermediate element. The difference is that when an element is referred to as "directly connected" or "directly coupled" to another element, there is no intermediate element. In all figures, the same reference numerals always represent the same element. As used herein, the term "and / or" includes any combination and all combinations of one or more related listed items.

[0089] First embodiment;

[0090] refer to Figure 1 Combination Figure 2 As shown, the flow chemistry experiment process safety monitoring system includes:

[0091] A plurality of sensors are arranged on the monitored experimental devices respectively, and are used to collect safety-related parameters of the flow chemistry experiment process in real time and send them to the data processing unit;

[0092] The following parameters that have a greater impact on safety are listed as safety-related parameters and further described as follows:

[0093] The main function of flow rate is to detect the flow of reagents, which is used to judge abnormalities of conveying equipment, pipeline leakage or blockage, etc.

[0094] Sensor selection: Select ultrasonic flowmeter, Coriolis flowmeter, electromagnetic flowmeter, etc. according to the characteristics of the reagents to detect the feeding conditions of the corresponding reagents. Pay special attention to the compatibility of the reagents and flowmeters, such as viscosity, polarity or non-polarity, whether it contains solids, whether it is easy to gasify and produce bubbles, etc., and make targeted improvements on the process pipelines:

[0095] 1) If hydrogen peroxide is easy to decompose in the pipeline to produce irregular oxygen bubbles, which affects the detection of the ultrasonic flow meter, a contact flow meter should be used, such as a Coriolis flow meter.

[0096] 2) If the photoreaction sometimes mixes the catalyst in the reagent for circulation, an ultrasonic flow meter should be used, and the reagent and catalyst should be fully mixed in the buffer bottle. The feed line should also be as short as possible to ensure that the liquid and solid are as evenly mixed as possible when reaching the monitoring point of the ultrasonic flow meter, with uniform ultrasonic propagation characteristics.

[0097] 3) For extremely small flow rates, such as hydrogenation or mg-level reactions, flow meters are generally difficult to measure. The "balance weight loss method" can be used to monitor the balance weight loss data per unit time, and then the volume flow rate can be calculated based on the density.

[0098] Installation location selection:

[0099] Generally, the flow sensor is arranged at the downstream of the pump, i.e. the outlet end, especially for syringe pumps or plunger pumps which first draw a certain amount and then discharge it at a uniform speed. If it is arranged at the upstream end of the pump, the detected flow rate will be in a periodic pulsed manner and cannot reflect the actual flow conditions.

[0100] The main function of temperature is to ensure the stability of chemical reagents and the controllability of the reaction process.

[0101] Sensor selection: Temperature sensors are generally divided into two categories: thermal resistors and thermocouples. The former are generally used in the range of 0 to 100°C with relatively good accuracy, while the latter are slightly less accurate, but have a wider measurement range. For example, the T-type thermocouple is -150 to 350°C, which basically covers the needs of chemical synthesis. That is, according to the process temperature range, select the appropriate temperature sensor type. The sheath also needs to comprehensively consider the compatibility of reagents, such as whether it is acid and alkali resistant, whether it is pressure resistant, etc.

[0102] Installation location selection: Select the appropriate measurement location based on the reaction type and reagent characteristics:

[0103] 1) If the nitration reaction is obviously exothermic, the reagent temperature in the pipeline should be measured at the two reagent mixers. In addition, the conventional quenching method is to drop the product directly into the ice-water mixture. If the product flow rate is too large or the stirring is not timely, there will be safety risks. Therefore, a temperature measurement point is set near the reagent outlet of the product quenching collection bottle.

[0104] 2) For reagents with boiling points close to room temperature, such as dichloromethane (40°C) and methanol (65°C), a temperature measuring point must be set in the raw material bottle, and certain cooling treatments must be performed, such as a cold water bath or an ice water bath, to reduce accidents caused by large amounts of volatilization of the reagents.

[0105] 3) For example, the temperature of the light-reacting LED light source, if the heat dissipation is poor and the heat is accumulated, it will not only affect the chemical reaction effect, but as mentioned above, if volatile organic compounds accumulate in the laboratory fume hood, it may even cause risks such as fire and explosion. Therefore, the temperature of the LED light board should be monitored in real time.

[0106] 4) For high-temperature and high-energy reactions, the reaction temperature conditions are relatively high, usually 150℃~350℃, and the temperature control equipment is a column oven. The process pipeline is made of metal, with good pressure resistance and thermal conductivity, but it is possible to conduct heat to the outside of the column oven. If personnel accidentally touch it, there is a risk of burns. If the reagent drips onto the pipeline, there is a risk of ignition. In addition, if the product comes out of the column oven, there is a risk of reagent volatilization or spontaneous combustion if the cooling is insufficient. If it is overcooled, there is a risk of solvent precipitation and pipe blockage. Therefore, temperature measurement points should also be set at the corresponding positions.

[0107] Pressure: Its main function is to detect the pressure in the reaction system and ensure that it is within the tolerance of the container or pipeline. If it is arranged at the upstream end of the feed, it can help predict system blockage or pipe burst.

[0108] Sensor selection:

[0109] 1) Range: Most flow chemical synthesis reactions are at normal pressure, that is, the reaction system pressure is within 0.3MPa, while the pressure of the PFA pipeline is within 1.5MPa. Therefore, a pressure transmitter with a range of less than 2MPa should be selected, which has a relatively good accuracy in the range of 0-0.3MPa. For high temperature and high energy or hydrogenation gases that require back pressure, the reaction system pressure is generally between 1.5 and 10MPa, and a pressure transmitter with a range of 10MPa should be selected.

[0110] 2) Material: In addition to the measuring range, the tolerance of the pressure transmitter diaphragm should also be considered. Hastelloy is preferred for organic reagents. If H2 is used, a gold-plated diaphragm should be selected to prevent hydrogen embrittlement.

[0111] Installation location selection:

[0112] 1) If monitoring the pressure in a container or coil reactor, the measuring point should be arranged at the target point. If the system is in an environment that is not conducive to direct installation of the sensor, such as high temperature, low temperature or immersion in liquid, the target position pressure can be led out through a pressure pipe. Note that the pressure pipe should be led upward and well insulated to prevent condensate from blocking the sensor.

[0113] 2) Flow chemistry basically adopts positive pressure delivery. If it is used to monitor whether the feed is normal or to predict blockage, it should be set 20 to 30 cm downstream from the pump outlet to reduce the impact of the pump's mechanical vibration on the pressure sensor.

[0114] Oxygen concentration has two main functions. One is to detect the oxygen concentration level in the cavity of high-temperature equipment, such as maintaining a slightly positive pressure nitrogen environment in a column oven or oven to prevent the risk of flash explosion when organic reagents mix with oxygen at high temperature when the pipeline ruptures or leaks; the second is to monitor nitrogen cabinets, nitrogen balloons, etc. Chemical reagents that are sensitive to oxygen, such as Dibal-H, Grignard reagents, and metal reagents such as butyl lithium, have very active chemical properties and will react or even spontaneously combust when in contact with oxygen in the air.

[0115] Sensor selection:

[0116] 1) Range: For example, the above two scenarios are mainly to detect low oxygen or anaerobic environments, so a range of 0 to 25% Vol. is more appropriate.

[0117] 1) Material: For the detection of high-temperature equipment cavity, since it is generally not in contact with chemical reagent vapor, conventional 304 or 316 stainless steel materials meet the requirements. However, for the detection of oxygen concentration in the gas in the reagent bottle, due to the volatilization of the reagent, a chemical corrosion-resistant material such as Hastelloy stainless steel is required, and pre-dehydration and deacidification treatment is required.

[0118] Installation location selection:

[0119] 1) Generally, a micro vacuum pump is required to draw the test gas into the sensor for detection.

[0120] 1) After being extracted from the system, it is necessary to cool down to room temperature, dehydrate the color-changing silica gel, and deacidify the lime particles to protect the safe operation of the sensor.

[0121] Liquid leakage detection, there are generally two situations for liquid leakage, one is that the reagents are spilled due to operating errors, which usually occurs in practice; the other is that since flow chemistry is basically positive pressure conveying, the reagents may leak at the place where the joints are not firmly connected in the process. In comparison, the latter is more harmful, such as a certain material leakage loss before the reaction leading to synthesis failure, the joint suddenly loosening and bursting the pipe causing splashing and injuring personnel or equipment safety, and the aforementioned reagent leakage and explosion accidents.

[0122] Sensor selection:

[0123] 1) Leakage detection sensors have different principles such as ultrasonic, infrared, conductivity, etc. Select the type that matches the actual contact liquid properties.

[0124] 2) Material. There are material requirements for contact type. Generally, the materials of sensor heads include stainless steel, polytetrafluoroethylene, etc.

[0125] Installation location selection:

[0126] 1) It is usually arranged at the joint, with a tray made of stainless steel or polytetrafluoroethylene. The sensor is arranged at the lowest point of the tray to ensure that it can be detected and alarmed immediately in the event of a small amount of leakage.

[0127] Combustible gas or toxic and harmful gas detection is used to monitor the concentration of flammable or toxic gases such as H2 and CO in the experimental environment to prevent harm to the safety of personnel or equipment.

[0128] Sensor selection:

[0129] 1) PPM-level accuracy is preferred, and the alarm threshold is set according to the actual situation, and explosion-proof standards are achieved when necessary.

[0130] 2) Material: Since it is generally not in direct contact with chemical reagents, 304 or 316 stainless steel can be selected.

[0131] Installation location options:

[0132] 1) Conventional installation: Generally, if the density of the measured gas is greater than that of air, it is arranged at a low position; otherwise, if the density is H2, it is arranged at the top where it gathers.

[0133] Ventilation equipment testing, such as fume hood glass door height testing:

[0134] Fume hoods have good negative pressure ventilation conditions, which can promptly discharge organic reagent vapors and even toxic and harmful gases from the experimental environment. The role of the glass door is to reduce the window opening area, ensure the stability of wind speed and direction, and prevent sudden reagent splashes from causing harm to personnel. However, in actual scenarios, experimental operators often forget to pull down the glass door of the fume hood, or do not pull it down enough, which cannot ensure the safety of the experiment. Therefore, it is crucial to master the real-time height of the fume hood glass door for experimental safety management.

[0135] Sensor selection:

[0136] 1) The shaft-connected pull-wire type is preferred to monitor the vertical linear displacement of the glass door, which has better stability in laboratory scenarios.

[0137] Installation location selection:

[0138] 1) Installed on the top outside the fume hood and combined with the lifting hinge structure of the fume hood glass door.

[0139] Personnel detection: For some dangerous reactions, such as hydrogenation, CO, nitration, etc., if personnel stay in front of the fume hood for a long time, the risk of safety violations will increase. By monitoring the personnel's stay time, timely reminders to leave can be given to reduce risks.

[0140] Sensor selection:

[0141] 1) The more common ones are infrared and radar principles, both of which have the sensitivity and stability to meet the needs. However, it is necessary to pay attention to selecting the appropriate irradiation area and distance to reduce misjudgment.

[0142] Installation location selection:

[0143] 1) It is usually installed at the bottom of the fume hood, shining towards the aisle, and detecting the corresponding signal when people stop.

[0144] A data processing unit receives sensor data, pre-processes the sensor data to form standardized data and sends it to the logic judgment unit;

[0145] The logic judgment unit performs program anomaly judgment on the standardized data and transmits the judgment result to the execution module. If the program is normal, the process ends. If the program is abnormal, it continues to judge whether the experimental program can be restored based on the execution status of the experimental program. If the experimental program cannot be restored, emergency measures and / or manual intervention are implemented.

[0146] Exemplarily, determining whether the experimental process can be resumed includes:

[0147] If it is caused by normal operation, then after the first delay, it is determined again whether the measured variable that caused the program abnormality has returned to normal; if it is not caused by normal operation, emergency measures are taken;

[0148] If the system returns to normal after the first delay, the monitoring ends; if the system does not return to normal after the first delay, it is judged that a safety anomaly has occurred and emergency measures are taken;

[0149] Enter the emergency measures and after the second delay, determine whether the measured variable that caused the program abnormality has returned to normal; if it has returned to normal, end the monitoring;

[0150] If it does not return to normal, human intervention is required.

[0151] Furthermore, the sensitivity setting of the logic judgment unit for abnormal detection can be selected according to the actual situation. For the safety monitoring system, there are inevitably two types of misjudgments, namely the first type of error (α risk) and the second type of error (β risk). The former is that the process involved is in a safe and controlled state but it is misjudged as out of control, that is, it is too sensitive; the latter is that it is actually out of control but it is misjudged as normal, that is, it is too slow. The two are like a seesaw, one rises and the other falls, and the appropriate relationship needs to be adjusted according to the actual application scenario. As far as flow chemistry experiments are concerned, the α risk caused by oversensitivity is generally more acceptable, and the β risk of being too slow is not preferred. The main reasons are as follows:

[0152] 1) The raw materials used in the pharmaceutical R&D process are extremely precious and are obtained through multiple steps of synthesis. If the synthesis is too slow and a safety accident occurs, it will lead to a serious waste of materials.

[0153] 2) Flow chemical reactions either require special conditions, such as high temperature and high pressure, or have special raw materials that are extremely prone to spontaneous combustion when exposed to water or air. In the early stages of safety anomalies, it is important to stop material transportation and chemical reactions in a timely manner to prevent the hazard from expanding.

[0154] 3) Compared with traditional kettle reactions, flow chemistry has the characteristic of small system liquid holding capacity. Even if the system is shut down due to misjudgment of risk, only the material in the system with liquid holding capacity will be wasted, and there will be no impact on the raw materials and the products that have been produced and collected. On the contrary, if the material transportation is not stopped in time when a safety abnormality occurs, the clean raw materials will be wasted and the previously collected products will be contaminated.

[0155] Further improving the first embodiment, the logic judgment unit also sends the original signal and standardized data of the safety-related parameters to the historical database of the central control system for storage, and also sends the judgment result to the process control system, and the process control system performs the corresponding preset operation according to the judgment result of the logic judgment unit. The historical database is a redundant backup and has permission management, which can record the login and browsing of the operating account for future reference.

[0156] The more common solution for the program to determine whether there is an abnormality is to set "four-level alarm values" (low limit LL, low limit L, high limit H, high limit HH). When the real-time process value (PV) reaches a certain level of alarm, the corresponding action is triggered.

[0157] However, since it can only respond to the real-time status of the PV process value, it is impossible to predict its changing trend in advance. Moreover, in laboratory scenarios, external interference or human factors affect the accuracy of variable detection, resulting in false alarms or even missed alarms, so the simple "four-level alarm value" solution has limited effect.

[0158] Therefore, the present invention provides a preferred specific implementation method for determining program abnormality, referring to Figure 3 As shown, trend calculation is added to improve the defects of the existing technology, including:

[0159] Determine whether to trigger a real-time value abnormal alarm based on the standardized data. If the real-time value abnormal alarm is triggered, further determine whether the duration of the real-time value abnormal alarm is greater than or equal to the time threshold t1;

[0160] Calculate parameter change trends based on standardized data;

[0161] If the parameter change trend abnormal alarm is triggered and the duration is greater than or equal to the time threshold t1, it is judged as a program abnormality;

[0162] Among them, the calculation parameter change trends include:

[0163] The changing trend is

[0164]

[0165] The real-time sensor collection value is V0, t calculates the sampling interval, and the historical values ​​of the previous moments are V1, V2, V3, V4, V5…V t ;

[0166] The rate of change before time m is k m ,m is the filtering parameter, dimensionless.

[0167] Furthermore, t and m are related to the type of measured variable, system size and other characteristics, for example:

[0168] 1) For the temperature measurement values ​​of TCU (Temperature Control Unit) or reaction system such as oil bath pot, high and low temperature circulating bath, the medium has large thermal inertia (affected by factors such as specific heat capacity, total mass, viscosity, and environmental heat dissipation), which is less affected by external interference. Therefore, smaller t and m values ​​can be used to judge abnormal changes.

[0169] 2) For the pressure measurement value of the reaction system, since flow chemistry relies on pumps to transport materials, the pump operation cycle (i.e., the pulse phenomenon, which exists regardless of whether it is a plunger pump, peristaltic pump, gear pump, diaphragm pump or syringe pump, but with differences in the size of the peaks and troughs or the size of the cycle) causes frequent pressure fluctuations. The exothermic gas production of chemical reactions can also cause pressure fluctuations. Therefore, larger t and m values ​​are required for calculations to eliminate disturbances that affect program judgment.

[0170] 3) For pipeline pressure of public works, such as N2 or H2, a stable high-pressure gas source is used, which is less affected by the outside world and can use smaller t and m values ​​to judge abnormal changes.

[0171] 4) For the detection values ​​of hydrogen H2, carbon monoxide CO or other gas content in the environment, the gas composition sensor is specific and less affected by other external interferences. Therefore, smaller t and m values ​​can be used for calculation to achieve more sensitive and faster prediction of abnormal occurrence.

[0172] Emergency measures are standardized actions that the program automatically performs related operations to eliminate dangerous factors and reduce risk losses after an abnormality occurs, which is exemplary;

[0173] 1) Divide the hazard level and perform different levels of operations for different abnormal levels; illustratively, it can be divided into two levels, the smaller the number, the higher the urgency, as shown in Table 1.

[0174] Table 1

[0175]

[0176] 2) The specific actions vary according to different reaction types and different risk factors, but the specific principles and methods are unified. An exemplary reference is shown in Table 2:

[0177] Table 2

[0178]

[0179] The present invention provides several common reaction flow chemistry experimental process safety monitoring systems, examples of which are shown in Table 3;

[0180] Table 3

[0181]

[0182]

[0183] Furthermore, taking the hydrogenation safety monitoring reaction as an example, the flow chemistry experiment process safety monitoring system architecture reference Figure 4 shown.

[0184] Exemplarily, the abnormality judgment method and emergency measures of the hydrogenation reaction are as follows;

[0185] Environmental testing: hydrogen concentration

[0186] Personnel protection: height of fume hood, duration of personnel stay

[0187] Reaction system: high temperature, high pressure

[0188] Due to the characteristics of the reaction, if there is excess hydrogen participating in the reaction, the unreacted H2 will be discharged from the system outlet along with the product, that is, there is a small amount of H2 continuously released in the fume hood environment. To ensure safety, it is necessary to ensure that: ① the exhaust of the fume hood is normal and can dilute and take away the H2 in time; ② the H2 concentration in the fume hood is far below the theoretical explosion limit of 4% Vol. (Note: The explosion limit refers to the volume ratio range of the gas in the air that will explode when encountering a fire source. The H2 explosion limit is 4% Vol. to 76% Vol., that is, if the volume concentration of H2 in the air is between 4% and 76%, it will explode when encountering a fire source. When the H2 concentration is less than 4% Vol. or 76% Vol., it will not explode even if it encounters a fire source.)

[0189] The program judges abnormal parameters as shown in Table 4 below;

[0190] Table 4

[0191]

[0192] The alarm classification settings are shown in Table 5 below;

[0193] Table 5

[0194]

[0195] Active safety: remind the fume hood door to be closed in time to maintain a good and stable exhaust wind speed.

[0196] The temperature of the reaction system exceeds 80°C. Open the fume hood and be careful of pipe burns.

[0197] Or, if the system pressure exceeds 300 kPa, it is a high pressure system and there is a risk of splashing.

[0198] If the fume hood is pulled up for too long, such as 10 minutes, remind the operator to operate safely and pull it down to a safe position.

[0199] Passive safety:

[0200] Pipeline pressure loss: (Judgment: whether the flow rate is actively adjusted and whether the generator is working normally) → If it is active, a reminder will be issued and the time will be set for 3 minutes. If it does not return to normal, upgrade measures → Close the H2 main pipe valve, stop the reaction device, and increase the exhaust.

[0201] H2 detection alarm: (determine whether the height of the fume hood door is normal → whether it is a short-term manual operation, determine whether the main pipe pressure is normal → determine whether it is accumulation or sudden leakage) → If it is a manual operation or accumulation, increase the exhaust to return to a safe level, and start the timer for 3 minutes. If it has not been reduced, upgrade the measures → Upgrade measures: close the H2 main pipe and stop the generator.

[0202] Exemplarily, the abnormality judgment method and emergency measures of nitrification reaction are as follows;

[0203] Environmental testing: None

[0204] Personnel protection: Fume hood protection glass door height

[0205] Reaction system: feed flow rate, reaction system pressure, quenching system temperature control

[0206] The reagents are concentrated sulfuric acid and concentrated nitric acid, which have high viscosity and require relatively high pressure to be transported in pipelines or microchannel reactors. If a peristaltic pump is used, the pump head tube will fatigue after long-term use and is prone to rupture and splashing. If a plunger pump is used, the pipeline will be blocked, and the overpressure will not automatically stop, and leaks and splashes from the joints will cause accidents. Therefore, real-time pressure monitoring and safety alarms are particularly important.

[0207] The quenching of the nitration reaction is to drop the product into ice or ice-water mixture, which can dilute the concentrated sulfuric acid and nitric acid with water to stop the reaction and absorb the large amount of heat released by the concentrated acid. However, if the quenching is not sufficient or the stirring in the bottle is not sufficient, thermal runaway is likely to occur, which may cause material splashing.

[0208] The program judges the abnormal parameters as shown in Table 6 below;

[0209]

[0210] Since the volume of the quenching bottle is limited and the product is continuously added into the bottle, the actual temperature of the quenching system is constantly rising. What needs to be controlled is that the real-time temperature value cannot exceed 0°C (that is, there must always be ice in the quenching system, because the phase change heat of ice melting into water is large and can absorb more heat release), and the heating rate cannot be too fast (to prevent thermal runaway due to insufficient local stirring).

[0211] The alarm classification settings are shown in Table 7 below;

[0212]

[0213] Active safety:

[0214] Fume hood door height detection

[0215] Pressure and temperature change trend curve analysis

[0216] Passive safety:

[0217] Sudden pressure loss or abnormal flow rate change (the actual value deviates from the theoretical value by 30%, which is considered to be leakage) → stop the pump and send an alarm

[0218] Temperature out of control: stop the pump → increase the cooling water circulation → alarm reminder, and monitor the temperature in real time. If it is above the safety line, it will remind you to pay attention to operational safety.

[0219] Blockage: Abnormal pressure change → stop pump → alarm reminder, and monitor the pressure in real time. If it is above the safety line, it will remind you to pay attention to operation safety.

[0220] Exemplarily, the abnormality judgment method and emergency measures of the light reaction are as follows;

[0221] Environmental detection: harmful wavelengths of light, such as ultraviolet or blue light

[0222] Personnel protection: height of fume hood, duration of personnel stay

[0223] Reaction system: reaction system pressure

[0224] If the environment monitor detects harmful light or the intensity is too high, it will remind you to operate with caution. Height of fume hood.

[0225] Photoreaction cycle, blockage, excessive pressure, and pipe burst.

[0226] Exemplarily, the abnormal judgment method and emergency measures of high temperature reaction are as follows;

[0227] Environmental testing: fume hood smoke detection, CO gas detection

[0228] Personnel protection: Fume hood protection glass door height

[0229] Reaction system: reaction system pressure / temperature, O2 concentration in the oven

[0230] Column oven, high temperature heat source, organic reagent vapor mixed with air, there is a risk of flash explosion.

[0231] Second embodiment;

[0232] The present invention provides a flow chemistry experiment process safety monitoring method, comprising the following steps:

[0233] Real-time collection of safety-related parameters of the flow chemistry experiment process, including flow, temperature, pressure, oxygen concentration, leakage detection, combustible gas detection, toxic and harmful gas detection, ventilation equipment detection and personnel detection;

[0234] Preprocess safety-related parameters to form standardized data;

[0235] The program abnormality is judged on the standardized data. If the program is normal, the process is terminated. If the program is abnormal, it is continued to determine whether the experimental program can be restored based on the execution status of the experimental program. If the experimental program cannot be restored, emergency measures and / or manual intervention are implemented.

[0236] Exemplarily, determining whether the experimental process can be resumed includes:

[0237] If it is caused by normal operation, then after the first delay, it is determined again whether the measured variable that caused the program abnormality has returned to normal; if it is not caused by normal operation, emergency measures are taken;

[0238] If the system returns to normal after the first delay, the monitoring ends; if the system does not return to normal after the first delay, it is judged that a safety anomaly has occurred and emergency measures are taken;

[0239] Enter the emergency measures and after the second delay, determine whether the measured variable that caused the program abnormality has returned to normal; if it has returned to normal, end the monitoring;

[0240] If it does not return to normal, human intervention is required.

[0241] Among them, the preferred program abnormality judgment includes:

[0242] Determine whether to trigger a real-time value abnormal alarm based on the standardized data. If the real-time value abnormal alarm is triggered, further determine whether the duration of the real-time value abnormal alarm is greater than or equal to the time threshold t1;

[0243] Calculate parameter change trends based on standardized data;

[0244] If the parameter change trend abnormal alarm is triggered and the duration is greater than or equal to the time threshold t1, it is judged as a program abnormality;

[0245] Calculation parameter change trends include:

[0246] The changing trend is

[0247]

[0248] The real-time sensor collection value is V0, t calculates the sampling interval, and the historical values ​​of the previous moments are V1, V2, V3, V4, V5…V t ;

[0249] The rate of change before time m is k m ,m is the filtering parameter, dimensionless.

[0250] Optionally, the second embodiment described above determines whether to trigger a real-time value abnormality alarm by comparing the real-time value with a design threshold;

[0251] The designed threshold is a multi-level threshold, each level of the threshold corresponds to a different alarm level, and each alarm level triggers a corresponding preset operation.

[0252] Optionally, the emergency measures of the second embodiment include:

[0253] Divide the hazard levels and assign different operations to each hazard level;

[0254] Query to obtain the current hazard level and perform preset operations based on the current hazard level.

[0255] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. It will also be understood that, unless expressly defined herein, terms such as those defined in general dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not interpreted in an ideal or overly formal sense.

[0256] The present invention has been described in detail above through specific implementation modes and embodiments, but these do not constitute limitations of the present invention. Without departing from the principles of the present invention, those skilled in the art may also make many variations and improvements, which should also be regarded as the protection scope of the present invention.

Claims

1. A flow chemistry experiment process safety monitoring system, characterized in that: include: A plurality of sensors are arranged on the monitored experimental devices respectively, and are used to collect safety-related parameters of the flow chemistry experiment process in real time and send them to the data processing unit; A data processing unit receives sensor data, pre-processes the sensor data to form standardized data and sends it to the logic judgment unit; The logic judgment unit performs program anomaly judgment on the standardized data and transmits the judgment result to the execution module. If the program is normal, the process ends. If the program is abnormal, it continues to judge whether the experimental program can be restored based on the execution status of the experimental program. If the experimental program cannot be restored, emergency measures and / or manual intervention are implemented.

2. The flow chemistry experiment process safety monitoring system according to claim 1, characterized in that: The process of determining whether the experiment can be resumed includes: If the program abnormality is caused by normal operation, then after the first delay, it is determined again whether the measured variable causing the program abnormality has returned to normal; if it is not caused by normal operation, emergency measures are taken; If the system returns to normal after the first delay, the monitoring ends; if the system does not return to normal after the first delay, it is judged that a safety anomaly has occurred and emergency measures are taken; Enter the emergency measures and after the second delay, determine whether the measured variable that caused the program abnormality has returned to normal; if it has returned to normal, end the monitoring; If it does not return to normal, human intervention is required.

3. The flow chemistry experiment process safety monitoring system according to claim 1, characterized in that: The logic judgment unit also sends the original signal and standardized data of the safety-related parameters to the historical database of the central control system for storage, and also sends the judgment result to the process control system. The process control system performs corresponding preset operations according to the judgment result of the logic judgment unit.

4. The flow chemistry experiment process safety monitoring system according to claim 1, characterized in that: Safety-related parameters include: flow, temperature, pressure, oxygen concentration, liquid leakage detection, combustible gas detection, toxic and hazardous gas detection, ventilation equipment detection and personnel detection.

5. The flow chemistry experiment process safety monitoring system according to claim 1, characterized in that: Program abnormality judgment includes: Determine whether to trigger a real-time value abnormal alarm based on the standardized data. If the real-time value abnormal alarm is triggered, further determine whether the duration of the real-time value abnormal alarm is greater than or equal to the time threshold t1; Calculate parameter change trends based on standardized data; If the parameter change trend abnormal alarm is triggered and the duration is greater than or equal to the time threshold t1, it is judged as a program abnormality.

6. The flow chemistry experiment process safety monitoring system according to claim 5, characterized in that: Calculation parameter change trends include: The changing trend is The real-time sensor collection value is V0, t calculates the sampling interval, and the historical values ​​of the previous moments are V1, V2, V3, V4, V5…V t ; The rate of change before time m is k m ,m is the filtering parameter, dimensionless.

7. The flow chemistry experiment process safety monitoring system according to claim 8, characterized in that: By comparing the real-time value with the designed threshold, it is determined whether to trigger the real-time value abnormal alarm; The designed threshold is a multi-level threshold, each level of the threshold corresponds to a different alarm level, and each alarm level triggers a corresponding preset operation.

8. The flow chemistry experiment process safety monitoring system according to claim 1, characterized in that: Emergency measures include: Divide the hazard levels and assign different operations to each hazard level; Query to obtain the current hazard level and perform preset operations based on the current hazard level.

9. A method for monitoring the safety of a flow chemistry experiment process, characterized in that: The following steps are involved: Real-time collection of safety-related parameters during flow chemistry experiments; Preprocess safety-related parameters to form standardized data; The program abnormality is judged on the standardized data. If the program is normal, the process is terminated. If the program is abnormal, it is continued to determine whether the experimental program can be restored based on the execution status of the experimental program. If the experimental program cannot be restored, emergency measures and / or manual intervention are implemented.

10. The flow chemistry experiment process safety monitoring method according to claim 9, characterized in that: The process of determining whether the experiment can be resumed includes: If the program abnormality is caused by normal operation, then after the first delay, it is determined again whether the measured variable causing the program abnormality has returned to normal; if it is not caused by normal operation, emergency measures are taken; If the system returns to normal after the first delay, the monitoring ends; if the system does not return to normal after the first delay, it is judged that a safety anomaly has occurred and emergency measures are taken; Enter the emergency measures and after the second delay, determine whether the measured variable that caused the program abnormality has returned to normal; if it has returned to normal, end the monitoring; If it does not return to normal, human intervention is required.

11. The flow chemistry experiment process safety monitoring method according to claim 9, characterized in that: Safety-related parameters include: flow, temperature, pressure, oxygen concentration, liquid leakage detection, combustible gas detection, toxic and hazardous gas detection, ventilation equipment detection and personnel detection.

12. The flow chemistry experiment process safety monitoring method according to claim 9, characterized in that: Program abnormality judgment includes: Determine whether to trigger a real-time value abnormal alarm based on the standardized data. If the real-time value abnormal alarm is triggered, further determine whether the duration of the real-time value abnormal alarm is greater than or equal to the time threshold t1; Calculate parameter change trends based on standardized data; If the parameter change trend abnormal alarm is triggered and the duration is greater than or equal to the time threshold t1, it is judged as a program abnormality.

13. The flow chemistry experiment process safety monitoring method according to claim 9, characterized in that: Calculation parameter change trends include: The changing trend is The real-time sensor collection value is V0, t calculates the sampling interval, and the historical values ​​of the previous moments are V1, V2, V3, V4, V5…V t ; The rate of change before time m is k m ,m is the filtering parameter, dimensionless.

14. The flow chemistry experiment process safety monitoring method according to claim 13, characterized in that: By comparing the real-time value with the designed threshold, it is determined whether to trigger the real-time value abnormal alarm; The designed threshold is a multi-level threshold, each level of the threshold corresponds to a different alarm level, and each alarm level triggers a corresponding preset operation.

15. The flow chemistry experiment process safety monitoring method according to claim 9, characterized in that: Emergency measures include: Divide the hazard levels and assign different operations to each hazard level; Query to obtain the current hazard level and perform preset operations based on the current hazard level.

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