Explosion-proof equipment safety performance detection method based on finite element simulation assistance
By using finite element simulation-assisted methods, a geometric model of explosion-proof equipment was established and strain was monitored in real time. This solved the problems of efficiency and accuracy in the safety performance testing of explosion-proof equipment, and achieved efficient and non-destructive safety performance assessment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2024-11-12
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies are insufficient for efficiently and accurately testing the safety performance of explosion-proof equipment, especially without stopping the equipment or damaging its structure.
A finite element simulation-assisted method is adopted to establish a geometric model by collecting parameters of the explosion-proof equipment, setting pressure values and solving key locations, and using strain gauges for real-time monitoring to determine the safety performance of the equipment.
It enables safety performance assessment of in-service explosion-proof equipment without stopping operation or damaging the equipment structure, with high measurement accuracy, improved efficiency and precision, and simple operation.
Smart Images
Figure CN122021091A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of explosion-proof equipment testing, and more particularly to a method for testing the safety performance of explosion-proof equipment based on finite element simulation. Background Technology
[0002] With the rapid development of my country's industrial technology, explosion-proof distribution boxes and explosion-proof equipment have been widely used in industries such as petrochemicals, transportation, and construction. Explosion-proof equipment possesses explosion-proof properties, preventing fires and explosions caused by sparks, high temperatures, and other factors. It is suitable for flammable and explosive locations, hazardous chemical plants, oilfield drilling platforms, and other similar areas. This type of equipment is flexible, convenient, and safe, and is widely used in industries such as petroleum, chemicals, power, highways, and mining, as well as in industrial production.
[0003] The common characteristic of explosion-proof electrical equipment is that it houses or separates components that may generate sparks under normal operating or accident conditions within one enclosure or several enclosures. Besides isolating internal sparks and arcs from the explosive gases in the surrounding environment, the connections between the internal components must possess not only specific structural dimensions but also sufficient structural strength. When an explosive gas mixture entering the enclosure is ignited by sparks or arcs within the enclosure, the enclosure itself will not be damaged, nor will the explosive material be allowed to ignite the surrounding explosive gas mixture through any gaps in the connections. This type of electrical equipment enclosure, capable of withstanding the explosion pressure of the internal explosive gas mixture and preventing the propagation of the internal explosion to the surrounding explosive mixture, is called an explosion-proof device; electrical equipment with explosion-proof devices is called explosion-proof electrical equipment.
[0004] Since explosion-proof equipment is commonly used in hazardous fields such as power, petroleum, and chemical industries, its safety and reliability must be guaranteed during use. Therefore, it is necessary to propose a method for efficiently and accurately testing the safety performance of explosion-proof equipment. Summary of the Invention
[0005] The purpose of this invention is to provide an efficient and accurate method for testing the safety performance of explosion-proof equipment based on finite element simulation.
[0006] This invention provides a method for testing the safety performance of explosion-proof equipment based on finite element simulation. This measurement method combines mechanical simulation to correlate the degree of deformation of the explosion-proof equipment with the stress value at a specific location. By using strain gauges, the degree of deformation of the tested object can be accurately and quickly obtained, thereby verifying the safety performance of the equipment.
[0007] To achieve the above functions, the present invention is implemented through the following measures: a method for testing the safety performance of explosion-proof equipment based on finite element simulation, the specific steps of which are as follows: A method for testing the safety performance of explosion-proof equipment based on finite element simulation, characterized in that the method specifically includes the following steps:
[0008] S1. Collect the parameters of the in-service explosion-proof equipment to be inspected and establish the corresponding geometric model;
[0009] S2. Set pressure values on the inner surface of the geometric model and solve for them to find the first and second key locations.
[0010] S3. Real-time monitoring of the strain at the corresponding first and second critical positions of the in-service explosion-proof equipment, and judgment of the safety performance of the explosion-proof equipment based on the monitoring results.
[0011] Specifically, step S1 is as follows:
[0012] S11. Obtain relevant parameters of the in-service explosion-proof equipment to be inspected; the relevant parameters include key parameters such as the external dimensions and explosion-proof clearance of the explosion-proof equipment; the specific dimensional parameters of the explosion-proof equipment can be measured by direct measurement method or indirect measurement method: direct measurement method: use measuring tools such as calipers, vernier calipers, micrometers to directly measure the external dimensions of the equipment. This method is suitable for measuring parameters such as the length, width, and height of the explosion-proof equipment shell; indirect measurement method: by measuring multiple parameters of the explosion-proof equipment, the dimensions to be measured are calculated using geometric relationships. For example, for some explosion-proof equipment with regular shapes, the dimensions to be measured can be calculated by measuring the length of two or more sides and then using geometric formulas such as the Pythagorean theorem.
[0013] S12. Build the geometric model of the explosion-proof device in the finite element simulation software, set the material of the geometric model, and divide the mesh, setting contact and mechanical conditions. Specifically, the geometric model sets the contact between the mating surfaces of the explosion-proof device as frictional contact, selects the "rough" option, and sets connection pairs on both the upper and lower surfaces of the same bolt when setting bolt connections. When adding fixed supports to the device, it is not limited to the bottom surface and can be set to any fixed position. The geometric model uses dotted lines to represent the bolts of the explosion-proof device. Furthermore, the material of the geometric model is the same as the material of the in-service explosion-proof device to be tested. Modeling complexity has a significant impact on solution time and computer performance; therefore, during modeling, areas with small deformation on the main body of the explosion-proof device can be ignored to speed up modeling and simulation calculations. When modeling bolts, since the bolt structure is not a primary consideration in this invention, dotted lines can be used to represent the bolts. At the same time, the mesh size needs to be set appropriately; too large a mesh will lead to excessive errors, while too small a mesh will slow down the calculation speed.
[0014] Step S2 specifically involves:
[0015] S21. Set different pressure values on the inner surface of the geometric model, solve the problem multiple times, and find the pressure value that allows the deformation at the joint surface of the explosion-proof device to reach the maximum allowable gap of the explosion-proof device. Record this pressure value as the first pressure value F1, mark the position 1 mm above this position as the first critical position, and record the maximum strain σ of the first critical position at this time. 1max The maximum gap is the value specified in standard GB / T3836.2.
[0016] S22. Set a second pressure value F2 on the inner surface of the geometric model. The second pressure value F2 is the sum of the explosion pressure F0 and the first pressure value F1. Solve to find the location of maximum deformation of the explosion-proof equipment material and mark it as the second critical location. Record the maximum strain σ at the second critical location at this time. 2max The location of maximum deformation of explosion-proof equipment materials is generally near the center of the top cover. This location can be quickly found using the maximum value label in simulation software. Specifically, the maximum strain σ at the second critical location... 2max It must not exceed the allowable stress of the material.
[0017] Step S3 specifically involves:
[0018] S31. Use a stress-strain detection device to monitor the strain at the first and second critical positions of the explosion-proof equipment in normal operation in real time.
[0019] S32, the measured maximum strain σ 1max and the maximum dependent variable σ 2max The safety performance of the explosion-proof device is determined by comparing it with the corresponding safety threshold σ' at each location; the safety threshold σ' is calculated as follows:
[0020] σ'=σ max / K;
[0021] Where, σ max K represents the maximum strain at the corresponding critical location, and K is the safety factor, which is usually taken as 1.5.
[0022] The method for determining the safety performance of the explosion-proof equipment in step S32 is as follows:
[0023] If the maximum strain σ 1max and the maximum dependent variable σ 2max If all values are below the corresponding safety threshold σ', the pressure-bearing capacity of the explosion-proof equipment is normal; otherwise, the pressure-bearing capacity of the explosion-proof equipment is judged to be abnormal.
[0024] The stress-strain monitoring device includes a strain gauge module, an excitation signal generation module, a signal processing module, and a data acquisition module. The strain gauge module includes a sensing element, a substrate, a cover layer, and leads. The sensing element is fixed to the substrate. The sensing element senses strain and converts it into a change in its resistance. It is typically made of constantan, nickel-chromium alloy, or semiconductor materials and is firmly fixed to the substrate with adhesive. The substrate is used to fix and protect the sensing element and accurately transmit the strain to it; the material can be paper, film, fiberglass cloth, etc. The cover layer protects the sensing element from the influence of dust, moisture, etc., in the external environment. The leads introduce the resistance change of the sensing element into subsequent circuitry.
[0025] The beneficial effects of this invention are as follows: the detection method of this invention can evaluate the safety performance of in-service explosion-proof equipment without stopping operation or damaging the equipment structure for measurement, and has high measurement accuracy and fast model calculation speed, effectively improving the efficiency and accuracy of detection; in addition, this invention can achieve accurate and rapid detection and evaluation of the safety performance of in-service explosion-proof equipment using only a testing device containing strain gauges, which is simple to operate, highly practical, and has great significance for promotion. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the simulation structure of the explosion-proof device in Embodiment 7 of the present invention. Detailed Implementation
[0027] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.
[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0030] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to describe the solution.
[0031] Example 1
[0032] This invention provides a method for testing the safety performance of explosion-proof equipment based on finite element simulation, the method specifically including the following steps:
[0033] S1. Collect the parameters of the in-service explosion-proof equipment to be inspected and establish the corresponding geometric model;
[0034] S2. Set pressure values on the inner surface of the geometric model and solve for them to find the first and second key locations.
[0035] S3. Real-time monitoring of the strain at the corresponding first and second critical positions of the in-service explosion-proof equipment, and judgment of the safety performance of the explosion-proof equipment based on the monitoring results.
[0036] Specifically, step S2 is as follows:
[0037] S21. Set different pressure values on the inner surface of the geometric model, solve the problem multiple times, and find the pressure value that allows the deformation at the joint surface of the explosion-proof device to reach the maximum allowable gap of the explosion-proof device. Record this pressure value as the first pressure value F1, mark the position 1 mm above this position as the first critical position, and record the maximum strain σ of the first critical position at this time. 1max The maximum gap is the value specified in standard GB / T3836.2.
[0038] S22. Set a second pressure value F2 on the inner surface of the geometric model. The second pressure value F2 is the sum of the explosion pressure F0 and the first pressure value F1. Solve to find the location of maximum deformation of the explosion-proof equipment material and mark it as the second critical location. Record the maximum strain σ at the second critical location at this time. 2max .
[0039] Step S3 is as follows:
[0040] S31. Use a stress-strain detection device to monitor the strain at the first and second critical positions of the explosion-proof equipment in normal operation in real time.
[0041] S32, the measured maximum strain σ 1max and the maximum dependent variable σ 2max The safety performance of the explosion-proof device is determined by comparing it with the corresponding safety threshold σ' at each location; the safety threshold σ' is calculated as follows:
[0042] σ'=σ max / K;
[0043] Where, σ max K represents the maximum strain at the corresponding critical location, and K is the safety factor, which is usually taken as 1.5.
[0044] The method for determining the safety performance of the explosion-proof equipment in step S32 is as follows:
[0045] If the maximum strain σ 1max and the maximum dependent variable σ 2max If all values are below the corresponding safety threshold σ', the pressure-bearing capacity of the explosion-proof equipment is normal; otherwise, the pressure-bearing capacity of the explosion-proof equipment is judged to be abnormal.
[0046] Example 2
[0047] This invention provides a method for testing the safety performance of explosion-proof equipment based on finite element simulation, which specifically includes the following steps:
[0048] S1. Collect the parameters of the in-service explosion-proof equipment to be inspected and establish the corresponding geometric model;
[0049] S2. Set pressure values on the inner surface of the geometric model and solve for them to find the first and second key locations.
[0050] S3. Real-time monitoring of the strain at the corresponding first and second critical positions of the in-service explosion-proof equipment, and judgment of the safety performance of the explosion-proof equipment based on the monitoring results.
[0051] Specifically, step S1 is as follows:
[0052] S11. Obtain relevant parameters of the in-service explosion-proof equipment to be inspected; the relevant parameters include key parameters such as the external dimensions and explosion-proof clearance of the explosion-proof equipment; the specific dimensional parameters of the explosion-proof equipment can be measured by direct measurement method or indirect measurement method: direct measurement method: use measuring tools such as calipers, vernier calipers, micrometers to directly measure the external dimensions of the equipment. This method is suitable for measuring parameters such as the length, width, and height of the explosion-proof equipment shell; indirect measurement method: by measuring multiple parameters of the explosion-proof equipment, the dimensions to be measured are calculated using geometric relationships. For example, for some explosion-proof equipment with regular shapes, the dimensions to be measured can be calculated by measuring the length of two or more sides and then using geometric formulas such as the Pythagorean theorem.
[0053] S12. Build the geometric model of the explosion-proof device in the finite element simulation software, set the material of the geometric model, and divide the mesh, setting contact and mechanical conditions. Specifically, the geometric model sets the contact between the mating surfaces of the explosion-proof device as frictional contact, selects the "rough" option, and sets connection pairs on both the upper and lower surfaces of the same bolt when setting bolt connections. When adding fixed supports to the device, it is not limited to the bottom surface and can be set to any fixed position. The geometric model uses dotted lines to represent the bolts of the explosion-proof device. Furthermore, the material of the geometric model is the same as the material of the in-service explosion-proof device to be tested. Modeling complexity has a significant impact on solution time and computer performance; therefore, during modeling, areas with small deformation on the main body of the explosion-proof device can be ignored to speed up modeling and simulation calculations. When modeling bolts, since the bolt structure is not a primary consideration in this invention, dotted lines can be used to represent the bolts. At the same time, the mesh size needs to be set appropriately; too large a mesh will lead to excessive errors, while too small a mesh will slow down the calculation speed.
[0054] Step S2 specifically involves:
[0055] S21. Set different pressure values on the inner surface of the geometric model, solve the problem multiple times, and find the pressure value that allows the deformation at the joint surface of the explosion-proof device to reach the maximum allowable gap of the explosion-proof device. Record this pressure value as the first pressure value F1, mark the position 1 mm above this position as the first critical position, and record the maximum strain σ of the first critical position at this time. 1max The maximum gap is the value specified in standard GB / T3836.2.
[0056] S22. Set a second pressure value F2 on the inner surface of the geometric model. The second pressure value F2 is the sum of the explosion pressure F0 and the first pressure value F1. Solve to find the location of maximum deformation of the explosion-proof equipment material and mark it as the second critical location. Record the maximum strain σ at the second critical location at this time. 2max .
[0057] Step S3 specifically involves:
[0058] S31. Use a stress-strain detection device to monitor the strain at the first and second critical positions of the explosion-proof equipment in normal operation in real time.
[0059] S32, the measured maximum strain σ 1max and the maximum dependent variable σ 2max The safety performance of the explosion-proof device is determined by comparing it with the corresponding safety threshold σ' at each location; the safety threshold σ' is calculated as follows:
[0060] σ'=σ max / K;
[0061] Where, σ max K represents the maximum strain at the corresponding critical location, and K is the safety factor, which is usually taken as 1.5.
[0062] The method for determining the safety performance of the explosion-proof equipment in step S32 is as follows:
[0063] If the maximum strain σ 1max and the maximum dependent variable σ 2max If all values are below the corresponding safety threshold σ', the pressure-bearing capacity of the explosion-proof equipment is normal; otherwise, the pressure-bearing capacity of the explosion-proof equipment is judged to be abnormal.
[0064] Example 3
[0065] This invention provides a method for testing the safety performance of explosion-proof equipment based on finite element simulation, characterized in that the method specifically includes the following steps:
[0066] S1. Collect the parameters of the in-service explosion-proof equipment to be inspected and establish the corresponding geometric model;
[0067] S2. Set pressure values on the inner surface of the geometric model and solve for them to find the first and second key locations.
[0068] S3. Real-time monitoring of the strain at the corresponding first and second critical positions of the in-service explosion-proof equipment, and judgment of the safety performance of the explosion-proof equipment based on the monitoring results.
[0069] Specifically, step S1 is as follows:
[0070] S11. Obtain relevant parameters of the in-service explosion-proof equipment to be inspected; the relevant parameters include key parameters such as the external dimensions and explosion-proof clearance of the explosion-proof equipment; the specific dimensional parameters of the explosion-proof equipment can be measured by direct measurement method or indirect measurement method: direct measurement method: use measuring tools such as calipers, vernier calipers, micrometers to directly measure the external dimensions of the equipment. This method is suitable for measuring parameters such as the length, width, and height of the explosion-proof equipment shell; indirect measurement method: by measuring multiple parameters of the explosion-proof equipment, the dimensions to be measured are calculated using geometric relationships. For example, for some explosion-proof equipment with regular shapes, the dimensions to be measured can be calculated by measuring the length of two or more sides and then using geometric formulas such as the Pythagorean theorem.
[0071] S12. Build the geometric model of the explosion-proof device in the finite element simulation software, set the material of the geometric model, and divide the mesh, setting contact and mechanical conditions. Specifically, the geometric model sets the contact between the mating surfaces of the explosion-proof device as frictional contact, selects the "rough" option, and sets connection pairs on both the upper and lower surfaces of the same bolt when setting bolt connections. When adding fixed supports to the device, it is not limited to the bottom surface and can be set to any fixed position. The geometric model uses dotted lines to represent the bolts of the explosion-proof device. Furthermore, the material of the geometric model is the same as the material of the in-service explosion-proof device to be tested. Modeling complexity has a significant impact on solution time and computer performance; therefore, during modeling, areas with small deformation on the main body of the explosion-proof device can be ignored to speed up modeling and simulation calculations. When modeling bolts, since the bolt structure is not a primary consideration in this invention, dotted lines can be used to represent the bolts. At the same time, the mesh size needs to be set appropriately; too large a mesh will lead to excessive errors, while too small a mesh will slow down the calculation speed.
[0072] Step S2 specifically involves:
[0073] S21. Set different pressure values on the inner surface of the geometric model, solve the problem multiple times, and find the pressure value that allows the deformation at the joint surface of the explosion-proof device to reach the maximum allowable gap of the explosion-proof device. Record this pressure value as the first pressure value F1, mark the position 1 mm above this position as the first critical position, and record the maximum strain σ of the first critical position at this time. 1max .
[0074] S22. Set a second pressure value F2 on the inner surface of the geometric model. The second pressure value F2 is the sum of the explosion pressure F0 and the first pressure value F1. Solve to find the location of maximum deformation of the explosion-proof equipment material and mark it as the second critical location. Record the maximum strain σ at the second critical location at this time. 2max .
[0075] Step S3 specifically involves:
[0076] S31. Use a stress-strain detection device to monitor the strain at the first and second critical positions of the explosion-proof equipment in normal operation in real time.
[0077] S32, the measured maximum strain σ 1max and the maximum dependent variable σ 2max The safety performance of the explosion-proof device is determined by comparing it with the corresponding safety threshold σ' at each location; the safety threshold σ' is calculated as follows:
[0078] σ'=σ max / K;
[0079] Where, σ max K represents the maximum strain at the corresponding critical location, and K is the safety factor, which is usually taken as 1.5.
[0080] The method for determining the safety performance of the explosion-proof equipment in step S32 is as follows:
[0081] If the maximum strain σ 1max and the maximum dependent variable σ 2max If all values are below the corresponding safety threshold σ', the pressure-bearing capacity of the explosion-proof equipment is normal; otherwise, the pressure-bearing capacity of the explosion-proof equipment is judged to be abnormal.
[0082] The stress-strain monitoring device includes a strain gauge module, an excitation signal generation module, a signal processing module, and a data acquisition module; the strain gauge module includes a sensitive element, a substrate, a cover layer, and leads; the sensitive element is fixed on the substrate.
[0083] Example 4
[0084] This invention provides a method for testing the safety performance of explosion-proof equipment based on finite element simulation, characterized in that the method specifically includes the following steps:
[0085] S1. Collect the parameters of the in-service explosion-proof equipment to be inspected and establish the corresponding geometric model;
[0086] S2. Set pressure values on the inner surface of the geometric model and solve for them to find the first and second key locations.
[0087] S3. Real-time monitoring of the strain at the corresponding first and second critical positions of the in-service explosion-proof equipment, and judgment of the safety performance of the explosion-proof equipment based on the monitoring results.
[0088] Specifically, step S1 is as follows:
[0089] S11. Obtain relevant parameters of the in-service explosion-proof equipment to be inspected; the relevant parameters include key parameters such as the external dimensions and explosion-proof gap of the explosion-proof equipment; the specific dimensional parameters of the explosion-proof equipment can be measured by direct measurement method or indirect measurement method.
[0090] S12. Build the geometric model of the explosion-proof device in the finite element simulation software, set the material of the geometric model, and divide the mesh, set the contact and mechanical conditions; wherein, the built geometric model sets the contact between the mating surfaces of the explosion-proof device as frictional contact.
[0091] Step S2 specifically involves:
[0092] S21. Set different pressure values on the inner surface of the geometric model, solve the problem multiple times, and find the pressure value that allows the deformation at the joint surface of the explosion-proof device to reach the maximum allowable gap of the explosion-proof device. Record this pressure value as the first pressure value F1, mark the position 1 mm above this position as the first critical position, and record the maximum strain σ of the first critical position at this time. 1max The maximum gap is the value specified in GB / T3836.2. When applying pressure to the inner wall of the explosion-proof equipment, the direction of the applied pressure must be strictly checked, and the pressure direction should be towards the outside of the explosion-proof equipment. When applying bolt preload to the bolt connection, the preload should be set according to specific requirements. In this embodiment of the invention, referring to GB_T3836.2, the bolt preload is set to 10000N.
[0093] S22. Set a second pressure value F2 on the inner surface of the geometric model. The second pressure value F2 is the sum of the explosion pressure F0 and the first pressure value F1. Solve to find the location of maximum deformation of the explosion-proof equipment material and mark it as the second critical location. Record the maximum strain σ at the second critical location at this time. 2max The location of maximum deformation of explosion-proof equipment materials is generally near the center of the top cover. The location of maximum deformation can be quickly found using the maximum value label in simulation software.
[0094] Step S3 specifically involves:
[0095] S31. Use a stress-strain detection device to monitor the strain at the first and second critical positions of the explosion-proof equipment in normal operation in real time.
[0096] S32, the measured maximum strain σ 1max and the maximum dependent variable σ 2max The safety performance of the explosion-proof device is determined by comparing it with the corresponding safety threshold σ' at each location; the safety threshold σ' is calculated as follows:
[0097] σ'=σ max / K;
[0098] Where, σ max K represents the maximum strain at the corresponding critical location, and K is the safety factor, which is usually taken as 1.5.
[0099] The method for determining the safety performance of the explosion-proof equipment in step S32 is as follows:
[0100] If the maximum strain σ 1max and the maximum dependent variable σ 2max If all values are below the corresponding safety threshold σ', the pressure-bearing capacity of the explosion-proof equipment is normal; otherwise, the pressure-bearing capacity of the explosion-proof equipment is judged to be abnormal.
[0101] The stress-strain monitoring device includes a strain gauge module, an excitation signal generation module, a signal processing module, and a data acquisition module. The strain gauge module includes a sensing element, a substrate, a cover layer, and leads. The sensing element is fixed to the substrate. The sensing element senses strain and converts it into a change in its resistance. It is typically made of constantan, nickel-chromium alloy, or semiconductor materials and is firmly fixed to the substrate with adhesive. The substrate is used to fix and protect the sensing element and accurately transmit the strain to it; the material can be paper, film, fiberglass cloth, etc. The cover layer protects the sensing element from the influence of dust, moisture, etc., in the external environment. The leads introduce the resistance change of the sensing element into subsequent circuitry.
[0102] Example 5
[0103] This invention provides a method for testing the safety performance of explosion-proof equipment based on finite element simulation, characterized in that the method specifically includes the following steps:
[0104] S1. Collect the parameters of the in-service explosion-proof equipment to be inspected and establish the corresponding geometric model;
[0105] S2. Set pressure values on the inner surface of the geometric model and solve for them to find the first and second key locations.
[0106] S3. Real-time monitoring of the strain at the corresponding first and second critical positions of the in-service explosion-proof equipment, and judgment of the safety performance of the explosion-proof equipment based on the monitoring results.
[0107] Specifically, step S1 is as follows:
[0108] S11. Obtain relevant parameters of the in-service explosion-proof equipment to be inspected; the relevant parameters include key parameters such as the external dimensions and explosion-proof clearance of the explosion-proof equipment; the specific dimensional parameters of the explosion-proof equipment can be measured by direct measurement method or indirect measurement method: direct measurement method: use measuring tools such as calipers, vernier calipers, micrometers to directly measure the external dimensions of the equipment. This method is suitable for measuring parameters such as the length, width, and height of the explosion-proof equipment shell; indirect measurement method: by measuring multiple parameters of the explosion-proof equipment, the dimensions to be measured are calculated using geometric relationships. For example, for some explosion-proof equipment with regular shapes, the dimensions to be measured can be calculated by measuring the length of two or more sides and then using geometric formulas such as the Pythagorean theorem.
[0109] S12. Build the geometric model of the explosion-proof device in the finite element simulation software, set the material of the geometric model, and divide the mesh, setting contact and mechanical conditions. Specifically, the geometric model sets the contact between the mating surfaces of the explosion-proof device as frictional contact, selects the "rough" option, and sets connection pairs on both the upper and lower surfaces of the same bolt when setting bolt connections. When adding fixed supports to the device, it is not limited to the bottom surface and can be set to any fixed position. The geometric model uses dotted lines to represent the bolts of the explosion-proof device. Furthermore, the material of the geometric model is the same as the material of the in-service explosion-proof device to be tested. Modeling complexity has a significant impact on solution time and computer performance; therefore, during modeling, areas with small deformation on the main body of the explosion-proof device can be ignored to speed up modeling and simulation calculations. When modeling bolts, since the bolt structure is not a primary consideration in this invention, dotted lines can be used to represent the bolts. At the same time, the mesh size needs to be set appropriately; too large a mesh will lead to excessive errors, while too small a mesh will slow down the calculation speed.
[0110] Step S2 specifically involves:
[0111] S21. Set different pressure values on the inner surface of the geometric model, solve the problem multiple times, and find the pressure value that allows the deformation at the joint surface of the explosion-proof device to reach the maximum allowable gap of the explosion-proof device. Record this pressure value as the first pressure value F1, mark the position 1 mm above this position as the first critical position, and record the maximum strain σ of the first critical position at this time. 1max The maximum gap is specified in GB / T3836.2. Taking type IIB equipment as an example, the maximum gap of the mating surface is selected as 0.15mm. When applying pressure to the inner wall of the explosion-proof equipment, the direction of the applied pressure must be strictly checked, and the pressure direction should be towards the outside of the explosion-proof equipment. When applying bolt preload to the bolt connection, the preload should be set according to the specific requirements. In this embodiment of the invention, referring to GB_T3836.2, the bolt preload is set to 10000N.
[0112] S22. Set a second pressure value F2 on the inner surface of the geometric model. The second pressure value F2 is the sum of the explosion pressure F0 and the first pressure value F1. Solve to find the location of maximum deformation of the explosion-proof equipment material and mark it as the second critical location. Record the maximum strain σ at the second critical location at this time. 2max The location of maximum deformation of explosion-proof equipment materials is generally near the center of the top cover. The location of maximum deformation can be quickly found using the maximum value label in simulation software.
[0113] Step S3 specifically involves:
[0114] S31. Use a stress-strain detection device to monitor the strain at the first and second critical positions of the explosion-proof equipment in normal operation in real time.
[0115] S32, the measured maximum strain σ 1max and the maximum dependent variable σ 2max The safety performance of the explosion-proof device is determined by comparing it with the corresponding safety threshold σ' at each location; the safety threshold σ' is calculated as follows:
[0116] σ'=σ max / K;
[0117] Where, σ max K represents the maximum strain at the corresponding critical location, and K is the safety factor, which is usually taken as 1.5.
[0118] The method for determining the safety performance of the explosion-proof equipment in step S32 is as follows:
[0119] If the maximum strain σ 1max and the maximum dependent variable σ 2max If all values are below the corresponding safety threshold σ', the pressure-bearing capacity of the explosion-proof equipment is normal; otherwise, the pressure-bearing capacity of the explosion-proof equipment is judged to be abnormal.
[0120] Example 6
[0121] This invention provides a method for testing the safety performance of explosion-proof equipment based on finite element simulation, characterized in that the method specifically includes the following steps:
[0122] S1. Collect the parameters of the in-service explosion-proof equipment to be inspected and establish the corresponding geometric model;
[0123] S2. Set pressure values on the inner surface of the geometric model and solve for them to find the first and second key locations.
[0124] S3. Real-time monitoring of the strain at the corresponding first and second critical positions of the in-service explosion-proof equipment, and judgment of the safety performance of the explosion-proof equipment based on the monitoring results.
[0125] Specifically, step S1 is as follows:
[0126] S11. Obtain relevant parameters of the in-service explosion-proof equipment to be inspected; the relevant parameters include key parameters such as the external dimensions and explosion-proof clearance of the explosion-proof equipment; the specific dimensional parameters of the explosion-proof equipment can be measured by direct measurement method or indirect measurement method: direct measurement method: use measuring tools such as calipers, vernier calipers, micrometers to directly measure the external dimensions of the equipment. This method is suitable for measuring parameters such as the length, width, and height of the explosion-proof equipment shell; indirect measurement method: by measuring multiple parameters of the explosion-proof equipment, the dimensions to be measured are calculated using geometric relationships. For example, for some explosion-proof equipment with regular shapes, the dimensions to be measured can be calculated by measuring the length of two or more sides and then using geometric formulas such as the Pythagorean theorem.
[0127] S12. Build the geometric model of the explosion-proof device in the finite element simulation software, set the material of the geometric model, and divide the mesh, setting contact and mechanical conditions. Specifically, the geometric model sets the contact between the mating surfaces of the explosion-proof device as frictional contact, selects the "rough" option, and sets connection pairs on both the upper and lower surfaces of the same bolt when setting bolt connections. When adding fixed supports to the device, it is not limited to the bottom surface and can be set to any fixed position. The geometric model uses dotted lines to represent the bolts of the explosion-proof device. Furthermore, the material of the geometric model is the same as the material of the in-service explosion-proof device to be tested. Modeling complexity has a significant impact on solution time and computer performance; therefore, during modeling, areas with small deformation on the main body of the explosion-proof device can be ignored to speed up modeling and simulation calculations. When modeling bolts, since the bolt structure is not a primary consideration in this invention, dotted lines can be used to represent the bolts. At the same time, the mesh size needs to be set appropriately; too large a mesh will lead to excessive errors, while too small a mesh will slow down the calculation speed.
[0128] Step S2 specifically involves:
[0129] S21. Set different pressure values on the inner surface of the geometric model, solve the problem multiple times, and find the pressure value that allows the deformation at the joint surface of the explosion-proof device to reach the maximum allowable gap of the explosion-proof device. Record this pressure value as the first pressure value F1, mark the position 1 mm above this position as the first critical position, and record the maximum strain σ of the first critical position at this time. 1maxThe maximum gap is specified in GB / T3836.2. Taking type IIB equipment as an example, the maximum gap of the mating surface is selected as 0.15mm. When applying pressure to the inner wall of the explosion-proof equipment, the direction of the applied pressure must be strictly checked, and the pressure direction should be towards the outside of the explosion-proof equipment. When applying bolt preload to the bolt connection, the preload should be set according to the specific requirements. In this embodiment of the invention, referring to GB_T3836.2, the bolt preload is set to 10000N.
[0130] S22. Set a second pressure value F2 on the inner surface of the geometric model. The second pressure value F2 is the sum of the explosion pressure F0 and the first pressure value F1. Solve to find the location of maximum deformation of the explosion-proof equipment material and mark it as the second critical location. Record the maximum strain σ at the second critical location at this time. 2max The location of maximum deformation of explosion-proof equipment materials is generally near the center of the top cover. This location can be quickly found using the maximum value label in simulation software. Specifically, the maximum strain σ at the second critical location... 2max It must not exceed the allowable stress of the material.
[0131] Step S3 specifically involves:
[0132] S31. Use a stress-strain detection device to monitor the strain at the first and second critical positions of the explosion-proof equipment in normal operation in real time.
[0133] S32, the measured maximum strain σ 1max and the maximum dependent variable σ 2max The safety performance of the explosion-proof device is determined by comparing it with the corresponding safety threshold σ' at each location; the safety threshold σ' is calculated as follows:
[0134] σ'=σ max / K;
[0135] Where, σ max K represents the maximum strain at the corresponding critical location, and K is the safety factor, which is usually taken as 1.5.
[0136] The method for determining the safety performance of the explosion-proof equipment in step S32 is as follows:
[0137] If the maximum strain σ 1max and the maximum dependent variable σ 2max If all values are below the corresponding safety threshold σ', the pressure-bearing capacity of the explosion-proof equipment is normal; otherwise, the pressure-bearing capacity of the explosion-proof equipment is judged to be abnormal.
[0138] The stress-strain monitoring device includes a strain gauge module, an excitation signal generation module, a signal processing module, and a data acquisition module. The strain gauge module includes a sensing element, a substrate, a cover layer, and leads. The sensing element is fixed to the substrate. The sensing element senses strain and converts it into a change in its resistance. It is typically made of constantan, nickel-chromium alloy, or semiconductor materials and is firmly fixed to the substrate with adhesive. The substrate is used to fix and protect the sensing element and accurately transmit the strain to it; the material can be paper, film, fiberglass cloth, etc. The cover layer protects the sensing element from the influence of dust, moisture, etc., in the external environment. The leads introduce the resistance change of the sensing element into subsequent circuitry.
[0139] Example 7
[0140] The testing method of Example 6 was used to conduct actual testing and evaluation on the in-service explosion-proof equipment - Xinliming AH-G11 / 2 Sanping explosion-proof junction box, in which... Figure 1 A schematic diagram of the simulation structure of the explosion-proof device, drawn using finite element simulation software.
[0141] First, without an explosion, the deformation at the critical location of the first position was measured using strain gauges. The measured deformation was 0.7e-4m, which is less than σ1=1.2e-4m, indicating that the explosion-proof equipment is within the safe range.
[0142] Then, assuming an explosion occurs, the maximum stress at the location of maximum deformation of the material measured by the measuring device is 350 MPa, which is less than the maximum strain value of the material, indicating that the material's performance meets the requirements.
[0143] It should be noted that the safety performance testing method for explosion-proof equipment based on finite element simulation provided by this invention is not limited to the maximum strain σ at a 1mm position obtained by measuring strain gauges through all the above steps. 1max Measure the maximum strain σ at the location of maximum deformation in the event of an explosion. 2max Of course, it is also possible to measure the maximum permissible pressure in the absence of an explosion by performing only some of the steps.
[0144] The technical features of this invention not described can be implemented by or using existing technology, and will not be repeated here. Of course, the above description is not a limitation of this invention, and this invention is not limited to the examples above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention should also be within the protection scope of this invention.
Claims
1. A method for testing the safety performance of explosion-proof equipment based on finite element simulation, characterized in that, The method specifically includes the following steps: S1. Collect the parameters of the in-service explosion-proof equipment to be inspected and establish the corresponding geometric model; S2. Set pressure values on the inner surface of the geometric model and solve for them to find the first and second key positions. S3. Real-time monitoring of the strain at the corresponding first and second critical positions of the in-service explosion-proof equipment, and judgment of the safety performance of the explosion-proof equipment based on the monitoring results.
2. The method for testing the safety performance of explosion-proof equipment according to claim 1, characterized in that, Step S1 specifically involves: S11. Obtain relevant parameters of the in-service explosion-proof equipment to be inspected; S12. Build the geometric model of the explosion-proof device in the finite element simulation software, set the material of the geometric model, and divide the mesh and set the contact and mechanical conditions.
3. The method for testing the safety performance of explosion-proof equipment according to claim 2, characterized in that, Step S2 specifically involves: S21. Set different pressure values on the inner surface of the geometric model, solve the problem multiple times, and find the pressure value that allows the deformation at the joint surface of the explosion-proof device to reach the maximum allowable gap of the explosion-proof device. Record this pressure value as the first pressure value F1, mark the position 1 mm above this position as the first critical position, and record the maximum strain σ of the first critical position at this time. 1max ; S22. Set a second pressure value F2 on the inner surface of the geometric model. The second pressure value F2 is the sum of the explosion pressure F0 and the first pressure value F1. Solve to find the location of maximum deformation of the explosion-proof equipment material and mark it as the second critical location. Record the maximum strain σ at the second critical location at this time. 2max .
4. The method for testing the safety performance of explosion-proof equipment according to claim 3, characterized in that, Step S3 specifically involves: S31. Use a stress-strain detection device to monitor the strain at the first and second critical positions of the explosion-proof equipment in normal operation in real time. S32, the measured maximum strain σ 1max and the maximum dependent variable σ 2max The safety performance of the explosion-proof device is determined by comparing it with the safety threshold σ' at the corresponding location.
5. The method for testing the safety performance of explosion-proof equipment according to claim 4, characterized in that, The method for calculating the safety threshold σ' in step S32 is as follows: σ'=σ max / K; Where, σ max K represents the maximum strain at the corresponding critical location, and K is the safety factor, which is usually taken as 1.
5.
6. The method for testing the safety performance of explosion-proof equipment according to claim 4, characterized in that, The method for determining the safety performance of the explosion-proof equipment in step S32 is as follows: If the maximum strain σ 1max and the maximum dependent variable σ 2max If all values are below the corresponding safety threshold σ', the pressure-bearing capacity of the explosion-proof equipment is normal; otherwise, the pressure-bearing capacity of the explosion-proof equipment is judged to be abnormal.
7. The method for testing the safety performance of explosion-proof equipment according to claim 2, characterized in that, In step S12, the geometric model is constructed by setting the contact between the mating surfaces of the explosion-proof equipment as a frictional contact.
8. The method for testing the safety performance of explosion-proof equipment according to claim 2, characterized in that, In step S12, the constructed geometric model uses dotted lines to represent the bolts of the explosion-proof device.
9. The method for testing the safety performance of explosion-proof equipment according to claim 4, characterized in that, The stress-strain monitoring device includes a strain gauge module, an excitation signal generation module, a signal processing module, and a data acquisition module; the strain gauge module includes a sensitive element, a substrate, a cover layer, and leads; the sensitive element is fixed on the substrate.