A safety risk assessment method and system for multi-factor coupling reactions in fine chemicals

Abstract

The present invention discloses a method and system for safety risk assessment of multi-factor coupling reaction of fine chemical industry, which relates to the field of chemical risk assessment and production safety, including: according to the reaction system type of chemical process, calculating the maximum pressure that can be reached after the reaction system loses control or the impact range of released flammable gas, and then determining the severity of reaction pressure loss control of the reaction system according to the first rating rule and the second rating rule; calculating the total flow rate of out-of-control reaction gas release, and determining the possibility of reaction pressure loss control according to the total release flow rate and the third rating rule; determining the acceptability of multi-factor coupling loss control according to the severity of reaction pressure loss control, the possibility of reaction pressure loss control and the multi-factor coupling matrix. The present invention can conduct safety risk assessment on fine continuous chemical production process, thereby controlling and reducing the risk factor and ensuring safe production.

Description

Technical Field

[0001] The present invention relates to the field of chemical industry risk assessment and production safety technology, and more specifically to a fine chemical industry multi-factor coupling reaction safety risk assessment method and system. Background Art

[0002] Fine chemicals can provide a variety of functional products for pharmaceuticals, machinery, electricity, textiles, food and other fields. Fine chemicals are complex and changeable, with high risks. Accidents can cause great losses and impacts. Therefore, it is particularly important to carry out fine chemical safety risk assessment.

[0003] However, on the one hand, the traditional research on fine chemical safety risk assessment mainly focuses on single-factor coupling analysis, that is, separate thermal risk assessment, and does not fully consider the impact of pressure in the reaction process. On the other hand, most of the traditional fine chemical production uses kettle reactors for intermittent production. With the transition of fine chemicals from intermittent or semi-batch production to continuous production processes, continuous production processes have become an increasingly important part of the fine chemical industry; however, the existing safety assessment still uses assessment methods for intermittent or semi-batch processes, and there is no very complete risk assessment method for the continuous production process of fine chemicals.

[0004] Therefore, how to conduct safety risk assessment on the continuous production process of fine chemicals is an urgent problem that technical personnel in this field need to solve. Summary of the invention

[0005] In view of this, the present invention provides a method and system for safety risk assessment of multi-factor coupled reactions in fine chemicals, thereby optimizing continuous production processes, controlling and reducing risk factors, and ensuring safe production.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention discloses a safety risk assessment method for fine chemical multi-factor coupling reaction, and the specific steps are as follows:

[0008] Determine the reaction system type of the chemical process. When the reaction system is a closed system, calculate the maximum pressure that can be reached after the reaction system loses control, and determine the severity of the reaction pressure loss of the reaction system based on the maximum pressure and the first rating rule. When the reaction system is an open system, calculate the impact range of the release of flammable gas after the reaction system loses control, and determine the severity of the reaction pressure loss of the reaction system based on the impact range and the second rating rule.

[0009] Calculating the total release flow rate of the runaway reaction gas, and determining the possibility of runaway reaction pressure according to the total release flow rate and a third rating rule;

[0010] The acceptability of the multi-factor coupling runaway is determined according to the reaction pressure runaway severity, the reaction pressure runaway possibility and the multi-factor coupling matrix.

[0011] Preferably, the maximum pressure that can be reached after the reaction system loses control is calculated as follows:

[0012] MPCS=P r +P d +P v ;

[0013] Among them, MPCS represents the maximum pressure that can be reached after the closed reaction system loses control, and the unit is Pascal (Pa); r Indicates the pressure caused by the reaction gas or inert gas, the unit is Pascal (Pa); P d Indicates the pressure of the gas generated during the secondary decomposition reaction, in Pascal (Pa); P v It represents the sum of the vapor pressures of substances in the system, and its unit is Pascal (Pa).

[0014] The first rating rule is: when the maximum pressure that can be reached after the reaction system loses control is lower than the starting pressure of the safety valve or bursting disc, the severity is Level 1; when it is higher than the starting pressure of the safety valve or bursting disc but lower than the equipment design pressure, the severity is Level 2; when it is higher than the equipment design pressure but not exceeding 1.05 times the design pressure, the severity is Level 3; when it is higher than 1.05 times the equipment design pressure, the severity is Level 4.

[0015] Preferably, the calculation formula for the impact range of the flammable gas released after the reaction system loses control is:

[0016]

[0017] Among them, IR GROS It represents the hemisphere radius when the flammable gas is diluted to the lower explosion limit, in meters (m); V represents the volume of flammable gas released by the system at normal temperature and pressure, in cubic meters (m 3 );L EL Represents the lower explosion limit of flammable gas, dimensionless.

[0018] The second rating rule is: if the range of impact of the release of flammable gas after the reaction system loses control is less than 10m, the severity is level 1; if it is 10-20m, the severity is level 2; if it is 20-50m, the severity is level 3; and if it is more than 50m, the severity is level 4.

[0019] Preferably, the calculation formula for the total flow rate of the uncontrolled reaction gas release is:

[0020] GRR=u r +u d +uv ;

[0021] Where GRR represents the total gas release rate in meters per second (m·s -1 );u r Indicates the gas release rate produced by the reaction, in meters per second (m·s -1 );u d Indicates the gas release rate produced by secondary decomposition, in meters per second (m·s -1 );u v Indicates the steam release flow rate in meters per second (m·s -1 ).

[0022] The third rating rule is: GRR<2m / s is the level 1 possibility of out of control; 2m / s≤GRR<8m / s is the level 2 possibility of out of control; 8m / s≤GRR<20m / s is the level 3 possibility of out of control; GRR≥20m / s is the level 4 possibility of out of control.

[0023] Preferably, the reaction produces a gas release rate u r The calculation formula is:

[0024]

[0025] Among them, n r Indicates the gas production of the reaction, in moles (mol); Q r Indicates the heat released by the target reaction in joules per kilogram (J·kg -1 ); S represents the cross-sectional area of ​​the exhaust or discharge port, in square meters (m 2 );q max(MTT) Indicates the maximum heat release rate at MTT temperature, in watts per kilogram (W kg -1 ).

[0026] Preferably, the secondary decomposition generates a gas release rate u d The calculation formula is:

[0027]

[0028] Among them, n d Indicates the gas production of the secondary decomposition reaction, in moles (mol); q d(MTT) It indicates the secondary decomposition reaction rate at MTT temperature, in watts per kilogram (W·kg -1 );Q d Indicates the heat released by the secondary decomposition reaction in joules per kilogram (J·kg -1 ).

[0029] Preferably, the steam release flow rate u v The calculation formula is:

[0030]

[0031] Among them, M r Indicates the total mass of materials in the reaction system, in kilograms (kg); ΔH v It indicates the heat of vaporization of volatile substances in joules per mole (J·mol -1 ).

[0032] The present invention also discloses a fine chemical multi-factor coupling reaction safety risk assessment system, comprising:

[0033] Out-of-control severity module: determine the reaction system type of the chemical process. When the reaction system is a closed system, calculate the maximum pressure that can be reached after the reaction system loses control, and determine the severity of the reaction pressure out-of-control of the reaction system based on the maximum pressure and the first rating rule; when the reaction system is an open system, calculate the impact range of the release of flammable gas after the reaction system loses control, and determine the severity of the reaction pressure out-of-control of the reaction system based on the impact range and the second rating rule;

[0034] Out-of-control possibility module: calculates the total release flow rate of out-of-control reaction gas, and determines the possibility of out-of-control reaction pressure according to the total release flow rate and the third rating rule;

[0035] The module for acceptability of out-of-control is used to determine the acceptability of multi-factor coupling out-of-control according to the severity of the reaction pressure out-of-control, the possibility of the reaction pressure out-of-control and the multi-factor coupling matrix.

[0036] It can be seen from the above technical solutions that compared with the prior art, the present invention discloses a method and system for safety risk assessment of multi-factor coupled reactions in fine chemicals, which improves the accuracy of safety risk assessment by calculating in detail the maximum pressure that can be reached by closed and open systems in the event of loss of control and the release impact range of flammable gases; the total flow rate of out-of-control reaction gas release is calculated to assess the possibility of reaction pressure loss of control; a multi-factor coupling matrix is ​​used to comprehensively assess the severity and possibility of reaction pressure loss of control to determine the acceptable degree of loss of control, thereby enhancing the comprehensiveness of the assessment. The present invention can conduct safety risk assessment on fine continuous chemical production processes, and chemical companies can quickly assess the safety risks of reaction systems according to actual conditions, guide safety management and operations, thereby controlling and reducing the risk factor and ensuring safe production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0038] Figure 1 It is a schematic diagram of the overall process of an embodiment of the present invention.

[0039] Figure 2 This is a graph showing the heat release rate of the nitration reaction during the feeding process of an embodiment of the present invention.

[0040] Figure 3 This is a graph showing the heat release rate of the nitration reaction during the heating and heat preservation process of an embodiment of the present invention.

[0041] Figure 4 This is a chromatographic analysis diagram of the materials in the reaction endpoint system of an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The embodiment of the present invention discloses a method for safety risk assessment of multi-factor coupling reaction in fine chemical industry, such as Figure 1 As shown, the specific steps are as follows:

[0044] Determine the type of reaction system of the chemical process. When the reaction system is a closed system, calculate the maximum pressure that can be reached after the reaction system loses control, and determine the severity of the reaction pressure loss of the reaction system based on the maximum pressure and the first rating rule. When the reaction system is an open system, calculate the impact range of the flammable gas released after the reaction system loses control, and determine the severity of the reaction pressure loss of the reaction system based on the impact range and the second rating rule.

[0045] Calculate the total release rate of the uncontrolled reaction gas, and determine the possibility of uncontrolled reaction pressure based on the total release rate and the third rating rule;

[0046] The acceptability of multi-factor coupling runaway is determined based on the severity of reaction pressure runaway, the possibility of reaction pressure runaway and the multi-factor coupling matrix.

[0047] In a specific embodiment, the maximum pressure that can be reached after the reaction system loses control is calculated as follows:

[0048] MPCS=P r +P d +P v ;

[0049] Among them, MPCS represents the maximum pressure that can be reached after the closed reaction system loses control, and the unit is Pascal (Pa); r Indicates the pressure caused by the reaction gas or inert gas, the unit is Pascal (Pa); P d Indicates the pressure of the gas generated during the secondary decomposition reaction, in Pascal (Pa); P v It represents the sum of the vapor pressures of substances in the system, and its unit is Pascal (Pa).

[0050] The first rating rule is: when the maximum pressure that can be reached after the reaction system loses control is lower than the starting pressure of the safety valve or bursting disc, the severity is Level 1; when it is higher than the starting pressure of the safety valve or bursting disc but lower than the equipment design pressure, the severity is Level 2; when it is higher than the equipment design pressure but not exceeding 1.05 times the design pressure, the severity is Level 3; when it is higher than 1.05 times the equipment design pressure, the severity is Level 4.

[0051] In a specific embodiment, the calculation formula for the impact range of the release of flammable gas after the reaction system loses control is:

[0052]

[0053] Among them, IR GROS It represents the hemisphere radius when the flammable gas is diluted to the lower explosion limit, in meters (m); V represents the volume of flammable gas released by the system at normal temperature and pressure, in cubic meters (m 3 );L EL Represents the lower explosion limit of flammable gas, dimensionless.

[0054] The second rating rule is: if the reaction system loses control and releases flammable gas, the impact range is less than 10m, with a severity of 1; 10-20m, with a severity of 2; 20-50m, with a severity of 3; and more than 50m, with a severity of 4.

[0055] In a specific embodiment, after the reaction system is out of control, when the maximum temperature that the process reaction can reach (MTSR) is lower than the technical maximum temperature (MTT), the possibility of a runaway reaction is low; when the MTSR is higher than the MTT, the total flow rate of the runaway reaction gas release is used to evaluate the possibility of multi-factor coupled runaway. The calculation formula for the total flow rate of the runaway reaction gas release is:

[0056] GRR=u r +u d +u v ;

[0057] Where GRR represents the total gas release rate in meters per second (m·s -1 );u r Indicates the gas release rate produced by the reaction, in meters per second (m·s -1 );u d Indicates the gas release rate produced by secondary decomposition, in meters per second (m·s -1 );u v Indicates the steam release flow rate in meters per second (m·s -1 ).

[0058] The third rating rule is: GRR<2m / s is the level 1 possibility of loss of control, which means it rarely happens; 2m / s≤GRR<8m / s is the level 2 possibility of loss of control, which means it happens occasionally; 8m / s≤GRR<20m / s is the level 3 possibility of loss of control, which means it is very likely to happen; GRR≥20m / s is the level 4 possibility of loss of control, which means it happens frequently.

[0059] In a specific embodiment, the reaction produces a gas discharge flow rate u r The calculation formula is:

[0060]

[0061] Among them, n r Indicates the gas production of the reaction, in moles (mol); Q r Indicates the heat released by the target reaction in joules per kilogram (J·kg -1 ); S represents the cross-sectional area of ​​the exhaust or discharge port, in square meters (m 2 );q max(MTT) Indicates the maximum heat release rate at MTT temperature, in watts per kilogram (W kg -1 ).

[0062] In a specific embodiment, the secondary decomposition produces a gas discharge flow rate u d The calculation formula is:

[0063]

[0064] Among them, n d Indicates the gas production of the secondary decomposition reaction, in moles (mol); q d(MTT) It indicates the secondary decomposition reaction rate at MTT temperature, in watts per kilogram (W·kg -1 );Q d Indicates the heat released by the secondary decomposition reaction in joules per kilogram (J·kg -1 ).

[0065] In a specific embodiment, the steam discharge flow rate u v The calculation formula is:

[0066]

[0067] Among them, M r Indicates the total mass of materials in the reaction system, in kilograms (kg); ΔH v It indicates the heat of vaporization of volatile substances in joules per mole (J·mol -1 ).

[0068] In a specific embodiment, the acceptability of multi-factor coupling out of control is evaluated by using the possibility of multi-factor coupling out of control and the severity of multi-factor coupling out of control as a matrix. The multi-factor coupling matrix is ​​shown in Table 1.

[0069] Table 1 Multi-factor coupling out-of-control risk assessment matrix

[0070]

[0071]

[0072] Among them, for level I risk, control measures should be taken in accordance with design requirements and specification requirements during the production process. For level II risk, control measures should be taken in accordance with design and specification requirements during the production process to ensure the effectiveness of control measures, and it is advisable to reduce the risk level through process optimization. For level III risk, it should be given priority to reduce the risk level through process optimization. For projects with high risks but requiring industrialization, control measures should be taken in accordance with design and specification requirements during the production process, necessary regional isolation should be taken, and automatic control should be fully realized.

[0073] The present invention also discloses a fine chemical multi-factor coupling reaction safety risk assessment system, comprising:

[0074] Out-of-control severity module: Determine the reaction system type of the chemical process. When the reaction system is a closed system, calculate the maximum pressure that can be reached after the reaction system loses control, and determine the severity of the reaction pressure out of control of the reaction system based on the maximum pressure and the first rating rule; when the reaction system is an open system, calculate the impact range of the flammable gas released after the reaction system loses control, and determine the severity of the reaction pressure out of control of the reaction system based on the impact range and the second rating rule;

[0075] Out-of-control possibility module: calculates the total release flow rate of out-of-control reaction gas, and determines the possibility of reaction pressure out-of-control based on the total release flow rate and the third rating rule;

[0076] Out-of-control acceptability module: Determines the acceptability of multi-factor coupling out-of-control based on the severity of reaction pressure out-of-control, the possibility of reaction pressure out-of-control and the multi-factor coupling matrix.

[0077] In a specific embodiment, a specific chemical process is used for illustration.

[0078] (1) Process description: Add nitric acid (70.7 kg, content 98%) into a 200L reactor, then add sulfuric acid (113.5 kg, content 95%) dropwise, control the reaction temperature at 30°C, add chlorobenzene (56.3 kg, content ≥ 99%) dropwise, and add for 60 min. After the addition is completed, heat to 80°C for 2 h, and then keep warm until the chlorobenzene is completely converted. The inner diameter of the reactor tail gas port is 40 mm.

[0079] (2) Analysis method: Gas chromatography was used for analysis. The chromatographic column was DB-170, 130 m × 0.25 mm × 0.25 um. The column box temperature was maintained at 60 °C for 2 min, increased at 20 °C / min to 250 °C and maintained for 5 min. The injector temperature was 250 °C and the detector temperature was 250 °C.

[0080] (3) Test process: Test results display (such as Figure 2 As shown in the figure, after chlorobenzene was added dropwise to the reactor, the system immediately released heat, and the reaction exothermic rate rapidly increased to a maximum value of 148.3W / kg (based on the instantaneous mass of the material in the reactor, the same below), and the reaction exothermic rate gradually decreased during the subsequent addition process. When the addition was completed, the reaction heat conversion rate was 58.2%, indicating that under the calorimetric conditions, after the addition was completed, there was a large amount of heat accumulation in the system; the average reaction exothermic rate during the addition process was 123.2W / kg.

[0081] The test results show (such as Figure 3 As shown), the temperature began to rise after the addition was completed. As the temperature increased, the heat release rate of the system gradually increased. When the system was heated to 49.9°C, the maximum heat release rate of the heating process was 51.9W / kg, and the reaction heat conversion rate was 73.5% at this time. The temperature continued to rise, and the reaction heat release rate gradually decreased. At the end of the heating, the reaction heat conversion rate was 89.5%, and the average heat release rate of the process was 27.0W / kg. After the heating was completed, insulation was started, and the heat release rate of the system gradually decreased during the insulation process. After about 4.6 hours of insulation, the system had basically no obvious heat release signal, and the average heat release rate of the process was 4.3W / kg.

[0082] (4) After the experiment, the material of the reaction end system was taken for chromatographic analysis. The analysis results showed (such as Figure 4 and shown in Table 2), the raw material reaction was complete.

[0083] Table 2 Reaction endpoint system material analysis table

[0084] name Retention time [min] Peak area [pA*min] Peak height [pA] Peak area% Product 1 11.324 10521.68 4070.07 87.78 Product 2 11.441 906.51 166.97 7.56 Product 3 12.547 172.57 23.92 1.44 other / / / 3.22

[0085] According to the experimental results, the specific heat capacity Cp of the material in the nitration reaction end point system is 1.90 kJ·kg-1 ·K -1 The nitration reaction is generally characterized by exothermic reaction, and the apparent heat of reaction Q m -2877.4 kJ·kg -1 (based on the mass of chlorobenzene, the same below), the adiabatic temperature rise is 355.4K. Among them, the feeding process is comprehensively characterized by heat release, and the apparent reaction heat is -1674.0kJ·kg -1 , the adiabatic temperature rise is 206.8K; the temperature rise process is generally characterized by exothermicity, and the apparent reaction heat is -900.9 kJ·kg -1 , the adiabatic temperature rise is 111.3K; the insulation process is comprehensively characterized by heat release, and the apparent reaction heat is -302.6 kJ·kg -1 , the adiabatic temperature rise is 37.4K.

[0086] (5) The secondary decomposition test results are shown in Table 3. The data in the table are all adiabatic calorimetry test results.

[0087] Table 3 Secondary decomposition test data

[0088] Test Information Test conditions and results Sample name Reaction end point system materials Sample amount / g 2.7366 Testing atmosphere Nitrogen Phi 2.41 Initial outgassing temperature / ℃ 98.4 Initial exothermic decomposition temperature / ℃ 154.0 Decomposition heat / (J / g) 950 Maximum temperature rise rate / (℃ / min) 916.8 Maximum pressure rise rate / (MPa / min) 52.3 Decomposition gas release (mol / kg) 2.81 <![CDATA[T D24 (℃)]]> 126

[0089] In the table, T D24 It indicates the temperature when the maximum reaction rate is reached in 24h under adiabatic conditions.

[0090] (6) Traditional reaction risk assessment: Decomposition heat, severity, possibility, risk acceptability and process hazard were assessed according to GB / T42300. The risk of thermal runaway of the material in this reaction is not high, the severity of the runaway reaction is "Level 3", and the possibility of the runaway reaction is "Level 3". The acceptability of the runaway reaction is "Level III" and the process hazard is Level 5.

[0091] (7) Multi-factor coupling evaluation:

[0092] 1) Multi-factor coupling severity assessment

[0093] The nitration reaction is an open system, the reactor volume is 200L, the total feed amount is 240.5kg, the boiling point of the system liquid at the end of the reaction is about 250℃, the decomposition gas release is 2.81mol / kg. The reaction temperature range is 30~80℃, and the maximum temperature MTSR of the runaway system is 178.7℃.

[0094] Considering the coupling of factors such as temperature and gas release, the severity of the multi-factor coupling risk of nitrification reaction is evaluated by using the gas release influence range corresponding to the maximum temperature of the runaway reaction. D24 , will cause secondary decomposition, the secondary decomposition gas release of the reaction system is:

[0095] Nd =2.81×240.5=675.8mol

[0096] At the same time, the heat released by the secondary decomposition will further increase the system temperature to 678.7℃, which is much higher than the boiling point of the system, causing all the organic materials in the system to vaporize (the vaporization heat of chlorobenzene is 40.9kJ / mol). The amount of steam generated in this process is N v That is, the molar amount of chlorobenzene is 500.4 mol. Considering that the lower explosion limit of the gas and organic vapor produced by secondary decomposition is 1%, the gas cloud volume when the secondary decomposition gas and vapor are diluted to the lower explosion limit concentration at normal temperature and pressure is:

[0097]

[0098] Where R is the ideal gas constant;

[0099] T is the ambient temperature, which is 25°C in this example.

[0100] Considering that the gas cloud is hemispherical and surrounds the leak, the hemispherical radius of the gas cloud is:

[0101]

[0102] Hemisphere radius IR FGROS The pressure of the uncontrolled reaction is 11.1m. According to the severity assessment results of the uncontrolled reaction pressure expansion, it can be seen that the danger level of the nitrification process is "Level 2". Once out of control, the temperature rise will cause the reaction system to release gas that covers the workshop area, causing damage to the factory.

[0103] 2) Multi-factor coupling possibility assessment

[0104] Since the process hazard level is "Level 5", D24 Coupled pressure and toxic release risk assessment, T D24 is 126°C. According to the reaction calorimetry data, the maximum exothermic power q under normal process conditions is max,Tp is 148.3W / kg. When the system is raised to T D24 When the maximum heat release power q max,TD24 The calculation is as follows:

[0105]

[0106] When the system rises to T D24 When the maximum heat release power q max,TD24 635.0W / kg

[0107] This exothermic power results in the steam releasing a molar flow rate n max for:

[0108]

[0109] The steam release volume flow rate v at normal temperature and pressure is:

[0110]

[0111] The tail gas outlet size is 40mm, and the steam gas flow rate is u v for:

[0112]

[0113] According to the process information, no obvious reaction gas is produced during the chlorobenzene nitration reaction; and the temperature of the reaction system is increased to T D24 The heat release rate of the decomposition reaction is extremely low, so the gas release rate u produced by the reaction can be ignored. r , and the secondary decomposition gas release rate u d Impact on the total flow rate of gas release. Therefore:

[0114] GRR=u v =56.6m / s

[0115] According to the results of the runaway reaction possibility assessment, it can be seen that the possibility of runaway reaction is "level 4", which is an "uncontrollable" risk. Once runaway reaction occurs, the generated steam cannot be discharged from the system in time, which can easily cause secondary disasters.

[0116] 3) Multi-factor coupling matrix evaluation

[0117] The reaction process was evaluated using the risk matrix, and the result showed a "Level III" risk. Priority should be given to reducing the risk level through process optimization. For projects with high risks that require industrialization, control measures should be taken during the production process in accordance with design and specification requirements, necessary area isolation should be adopted, and full automatic control should be achieved.

[0118] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0119] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for safety risk assessment of multi-factor coupling reactions in fine chemicals, characterized in that: The specific steps are as follows: Determine the reaction system type of the chemical process. When the reaction system is a closed system, calculate the maximum pressure that can be reached after the reaction system loses control, and determine the severity of the reaction pressure loss of the reaction system based on the maximum pressure and the first rating rule. When the reaction system is an open system, calculate the impact range of the release of flammable gas after the reaction system loses control, and determine the severity of the reaction pressure loss of the reaction system based on the impact range and the second rating rule. Calculating the total release flow rate of the runaway reaction gas, and determining the possibility of runaway reaction pressure according to the total release flow rate and a third rating rule; The acceptability of the multi-factor coupling runaway is determined according to the reaction pressure runaway severity, the reaction pressure runaway possibility and the multi-factor coupling matrix.

2. A method for safety risk assessment of multi-factor coupling reactions in fine chemicals according to claim 1, characterized in that: The calculation formula for the maximum pressure that the reaction system can reach after losing control is: MPCS=P r +P d +P v ; MPCS is the maximum pressure that can be reached after the closed reaction system loses control, in Pascals; r Indicates the pressure caused by the reaction gas or inert gas, in Pascal; P d Indicates the pressure of the gas generated during the secondary decomposition reaction, in Pascals; P v It represents the sum of the vapor pressures of substances in the system, in Pascals.

3. A method for safety risk assessment of multi-factor coupling reactions in fine chemicals according to claim 1, characterized in that: The calculation formula for the impact range of the flammable gas released after the reaction system loses control is: Among them, IR GROS It represents the hemisphere radius when the flammable gas is diluted to the lower explosion limit, in meters; V represents the volume of flammable gas released by the system at normal temperature and pressure when it is out of control, in cubic meters; L EL Represents the lower explosion limit of flammable gas, dimensionless.

4. A method for safety risk assessment of multi-factor coupling reactions in fine chemicals according to claim 1, characterized in that: The calculation formula for the total flow rate of the uncontrolled reaction gas release is: GRR=u r +in d +in v ; Where GRR represents the total gas release rate in meters per second; u r Indicates the gas release rate produced by the reaction, in meters per second; u d Indicates the gas release rate produced by secondary decomposition, in meters per second; u v Indicates the steam release flow rate in meters per second.

5. A method for safety risk assessment of multi-factor coupling reactions in fine chemicals according to claim 4, characterized in that: The reaction produces a gas release flow rate u r The calculation formula is: Among them, n r Indicates the gas production of the reaction, in moles; Q r represents the heat released by the target reaction, in joules per kilogram; S represents the cross-sectional area of ​​the exhaust or discharge port, in square meters; q max(MTT) Indicates the maximum heat release rate at the MTT temperature, in watts per kilogram.

6. A method for safety risk assessment of multi-factor coupling reactions in fine chemicals according to claim 4, characterized in that: The secondary decomposition produces a gas release flow rate u d The calculation formula is: Among them, n d Indicates the gas production of the secondary decomposition reaction, in moles; q d(MTT) It represents the secondary decomposition reaction rate at MTT temperature, in watts per kilogram; S represents the cross-sectional area of ​​the exhaust or discharge port, in square meters; Q d It represents the heat released by the secondary decomposition reaction in joules per kilogram.

7. A method for safety risk assessment of multi-factor coupling reactions in fine chemicals according to claim 4, characterized in that: The steam release flow rate u v The calculation formula is: Among them, M r Indicates the total mass of materials in the reaction system, in kilograms; ΔH v It represents the heat of vaporization of volatile substances in joules per mole; q max(MTT) Indicates the maximum heat release rate at MTT temperature, in watts per kilogram; q d(MTT) It represents the secondary decomposition reaction rate at MTT temperature, in watts per kilogram.

8. A fine chemical multi-factor coupling reaction safety risk assessment system, using a fine chemical multi-factor coupling reaction safety risk assessment method according to any one of claims 1 to 7, characterized in that: include: Out-of-control severity module: determine the reaction system type of the chemical process. When the reaction system is a closed system, calculate the maximum pressure that can be reached after the reaction system loses control, and determine the severity of the reaction pressure out-of-control of the reaction system based on the maximum pressure and the first rating rule; when the reaction system is an open system, calculate the impact range of the release of flammable gas after the reaction system loses control, and determine the severity of the reaction pressure out-of-control of the reaction system based on the impact range and the second rating rule; Out-of-control possibility module: calculates the total release flow rate of out-of-control reaction gas, and determines the possibility of out-of-control reaction pressure according to the total release flow rate and the third rating rule; The module for acceptability of out-of-control is used to determine the acceptability of multi-factor coupling out-of-control according to the severity of the reaction pressure out-of-control, the possibility of the reaction pressure out-of-control and the multi-factor coupling matrix.

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