Risk-based inspection method and system for pressure-bearing equipment of LNG (Liquefied Natural Gas) filling station in plateau region, processing equipment and storage medium

Abstract

The invention relates to a risk-based detection method and system for pressure-bearing equipment of an LNG (Liquefied Natural Gas) filling station in a plateau region, processing equipment and a storage medium. The method comprises the following steps: acquiring equipment daily operation parameters, equipment composition material characteristics, holding medium characteristics and environmental data of the pressure-bearing equipment of the LNG filling station to be detected in the plateau region; inputting the obtained equipment daily operation parameters, the equipment composition material characteristics, the holding medium characteristics and the environmental data into a pre-constructed LNG gas station pressure-bearing equipment RBI quantitative model to obtain the failure probability and the consequence severity of the LNG gas station pressure-bearing equipment to be detected; according to the obtained failure probability and consequence severity, the risk level of the LNG gas station pressure-bearing equipment to be detected is determined; and according to the risk level of the to-be-detected LNG gas station pressure-bearing equipment and a pre-specified detection plan, the to-be-detected LNG gas station pressure-bearing equipment is correspondingly detected, and the method and the device can be widely applied to the detection field.

Description

Technical Field

[0001] This invention relates to the field of inspection, and in particular to a risk-based inspection (RBI) method, system, processing equipment, and storage medium for pressure-bearing equipment in LNG (liquefied natural gas) refueling stations. Background Technology

[0002] As a crucial component of clean energy infrastructure, the safety of pressurized equipment at LNG refueling stations directly determines the stability of the energy system. Equipment failures not only cause power outages and economic and social losses, but may also trigger catastrophic accidents such as leaks and explosions. The current fixed-period inspection system suffers from a double contradiction: excessive maintenance of low-risk equipment coexists with blind spots in the detection of high-risk areas. At the same time, the shutdown inspection model suffers from a lack of real-time data support, leading to a lag in defect identification.

[0003] Risk-Based Inspection (RBI) improves safety performance through three levels of optimization: 1) Constructing a risk matrix to achieve hierarchical management and control, reducing inspection costs by 30%-40% by focusing resources on high-risk components; 2) Integrating real-time monitoring data to establish a dynamic evaluation mechanism, improving the hazard identification rate by 25% under continuous operation and reducing downtime losses by 15%-20% through time-series optimization; 3) Providing 72-hour risk warnings based on a failure probability prediction model, controlling the sudden failure rate below 0.5‰. Applications in other regions of China show that the RBI method can reduce annual maintenance costs by 18%-22% and reduce unplanned downtime by 40%.

[0004] For special working conditions at high altitudes (>2000m) and low temperatures (annual average -5℃), research has found that environmental factors significantly exacerbate the risk of equipment failure through mechanisms such as low-temperature material embrittlement, alternating thermal stress, and abnormal generation of BOG (Boil Off Gas) at high altitudes. For example, the annual defect rate of the vacuum insulation layer of the storage tank increases by 12.5% ​​due to the uneven settlement of perlite driven by temperature difference. The corrosion rate of welds in process pipelines reaches 0.15mm / a (40% higher than in plains areas) under the coupled effect of low-temperature contraction and vibration. The lifespan of valve sealing rings is shortened by 30% compared to the design value under the combined effect of ultraviolet radiation and low-temperature hardening at high altitudes.

[0005] However, current RBI methods have significant limitations for special operating conditions at high altitudes and low temperatures: 1) General models do not consider high-altitude pressure correction coefficients (e.g., BOG generation rate calculation deviation > 15%), leading to distorted assessment of leakage consequences; 2) The standard environmental load spectrum is mismatched with the actual temperature fluctuations (daily range 15℃) under special operating conditions, resulting in a pipeline stress fatigue life prediction error of up to 25%; 3) Static risk classification mechanisms are difficult to adapt to dynamic risk mutations caused by sudden extreme weather events at high altitudes. Therefore, it is urgent to construct a localized RBI model that integrates real-time environmental feedback for special operating conditions at high altitudes and low temperatures. By considering the relationship between altitude, temperature difference changes, earthquakes, and equipment risks, this model can provide relatively scientific decision support for the safety management of LNG equipment in high-altitude and low-temperature environments. Summary of the Invention

[0006] To address the aforementioned problems, the purpose of this invention is to provide a risk-based inspection method, system, processing equipment, and storage medium for LNG refueling station pressure equipment in high-altitude and low-temperature special operating conditions.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: Firstly, it provides a risk-based inspection method for pressure-bearing equipment in LNG refueling stations in plateau areas, comprising:

[0008] To obtain daily operating parameters, material properties of the equipment, properties of the contained medium, and environmental data of the pressure-bearing equipment of the LNG refueling station to be tested in the plateau region;

[0009] The acquired daily operating parameters of the equipment, the material properties of the equipment components, the properties of the container medium, and environmental data are input into the pre-built RBI quantitative model of the pressure equipment of the LNG refueling station to obtain the failure probability and the severity of the consequences of the pressure equipment of the LNG refueling station under test.

[0010] Based on the obtained failure probability and severity of consequences, the risk level of the pressure equipment in the LNG refueling station under test is determined;

[0011] Based on the risk level of the pressure-bearing equipment of the LNG refueling station to be tested and the pre-specified inspection plan, the corresponding inspection is carried out on the pressure-bearing equipment of the LNG refueling station to be tested.

[0012] Furthermore, the RBI quantitative model for the pressure-bearing equipment of the LNG refueling station is established based on the characteristics of high altitude, large temperature difference and earthquake risk, including failure probability calculation equation and consequence severity equation.

[0013] Furthermore, the failure probability calculation equation is as follows:

[0014] P of =α·σ corr ·K H ·t·β·N ΔT·∈ fatigue ·γ·PGA·S geo

[0015] Among them, P of σ represents the failure probability. corr H represents the corrosion rate; H represents the altitude of the equipment's location; K represents the corrosion rate. H t is the altitude correction factor; t is time; N ΔT The annual temperature range cycle number; ∈ fatigue The single-cycle thermal stress damage factor is represented by S; PGA is the peak ground acceleration; S geo α is the geological amplification factor; β and γ are weighting coefficients.

[0016] The severity equation for consequences is:

[0017] C of =λ·Q leak ·C LNG ·F ignition ·R pop ·η·E env

[0018] Among them, C of For the severity of the consequences; Q leak Leakage equivalent; C LNG F is the diffusion coefficient of methane; ignition R represents the ignition probability. pop E represents the population exposure coefficient. env Environmental sensitivity; λ and η are weighting factors;

[0019] The risk index matrix equation is as follows:

[0020] R = P of ×C of ×K maintenance

[0021] Where R is the overall risk value; K maintenance For maintenance and repair correction factors.

[0022] Furthermore, the daily operating parameters of the equipment include operating pressure, leakage equivalent, and maintenance correction factor; the material properties of the equipment components include single temperature difference stress cycle damage factor and corrosion rate; the properties of the contained medium include methane diffusion coefficient and ignition probability; and the environmental data include the altitude of the equipment's location, population exposure coefficient, environmental sensitivity, annual temperature difference cycle number, peak ground acceleration, and geological amplification factor.

[0023] Furthermore, determining the risk level of the pressure-bearing equipment at the LNG refueling station under test based on the obtained failure probability and severity of consequences includes:

[0024] Based on the obtained failure probability and severity of consequences, and in accordance with the pre-set inspection implementation guidelines, the failure probability level and failure consequence level of the pressure equipment of the LNG refueling station under test in the plateau area are determined.

[0025] Based on the failure probability level and failure consequence level of the pressure-bearing equipment of the LNG refueling station under test in the plateau region, the risk level of the pressure-bearing equipment of the LNG refueling station under test is determined, including high risk level, medium-high risk level, medium risk level and low risk level.

[0026] Furthermore, determining the risk level of the pressure-bearing equipment at the LNG refueling station under test includes:

[0027] Based on the obtained failure probability level and failure consequence level, and combined with the actual operation, the acceptable level of risk is comprehensively assessed. Based on the pre-set risk matrix, the risk level of the pressure equipment of the LNG refueling station under test is determined. The columns of the risk matrix represent the failure consequence level, and the behavior of the risk matrix represents the failure probability level.

[0028] Alternatively, based on the obtained failure probability level and failure consequence level, calculate the comprehensive risk value, and determine the risk level of the pressure equipment of the LNG refueling station to be tested according to the pre-set risk classification principle.

[0029] Furthermore, the step of conducting corresponding inspections on the pressure-bearing equipment of the LNG refueling station under test, based on the risk level and pre-designated inspection plan, includes:

[0030] Develop corresponding inspection plans for each risk level;

[0031] Based on the pre-established inspection plan, and according to the risk level of the pressure equipment of the LNG refueling station to be tested, the corresponding inspection is carried out on the pressure equipment of the LNG refueling station to be tested.

[0032] Secondly, a risk-based inspection system for pressure-bearing equipment at LNG refueling stations in high-altitude areas is provided, comprising:

[0033] The data acquisition module is used to acquire the daily operating parameters, material properties of the equipment, properties of the container medium, and environmental data of the pressure-bearing equipment of the LNG refueling station to be tested in the plateau region.

[0034] The RBI quantification module is used to input the acquired daily operating parameters of the equipment, the material characteristics of the equipment components, the characteristics of the container medium, and environmental data into the pre-built RBI quantification model of the pressure equipment of the LNG refueling station, so as to obtain the failure probability and the severity of the consequences of the pressure equipment of the LNG refueling station under test.

[0035] The risk level determination module is used to determine the risk level of the pressure equipment in the LNG refueling station under test based on the obtained failure probability and severity of consequences.

[0036] The inspection determination module is used to conduct corresponding inspections on the pressure equipment of the LNG refueling station under test according to the risk level and the pre-specified inspection plan.

[0037] Thirdly, a processing device is provided, including computer program instructions, wherein when the computer program instructions are executed by the processing device, they are used to implement the steps corresponding to the risk-based inspection method for the pressure-bearing equipment of the LNG refueling station in the plateau region described above.

[0038] Fourthly, a computer-readable storage medium is provided, wherein computer program instructions are stored on the computer-readable storage medium, wherein when the computer program instructions are executed by a processor, they are used to implement the steps corresponding to the risk-based inspection method for the pressure-bearing equipment of the LNG refueling station in the plateau region described above.

[0039] The present invention has the following advantages due to the adoption of the above technical solutions:

[0040] 1. This invention, through quantifying risks (such as corrosion rate and seismic parameters) and using dynamic adjustment strategies, can significantly reduce operation and maintenance costs while ensuring safety.

[0041] 2. This invention addresses the problems of material embrittlement and sealing failure that are easily caused by high-altitude and low-temperature environments. By quantitatively analyzing the failure probability and consequences, it can prioritize the inspection of high-risk LNG refueling station pressure equipment (such as LNG storage tank welds and cryogenic pipelines). This avoids the waste of resources caused by the traditional "one-size-fits-all" inspection. In earthquake-prone areas, equipment inspection can be combined with historical earthquake damage data to focus on assessing the seismic weaknesses of LNG refueling station pressure equipment, thereby achieving precise risk management.

[0042] 3. This invention uses online detection methods such as infrared thermal imaging and acoustic emission monitoring, which can achieve detection without stopping the machine or removing the insulation layer, solving the problem of energy supply interruption caused by the need to stop the machine and ventilate in traditional inspections. It is particularly suitable for key equipment for peak shaving and supply guarantee, and improves inspection efficiency.

[0043] 4. This invention concentrates inspection resources on high-risk LNG refueling station pressure equipment through a pre-constructed risk matrix, which can reduce the overall inspection frequency. Data shows that this invention can reduce inspection costs and reduce secondary damage caused by disassembly, thus optimizing costs.

[0044] 5. This invention can dynamically adjust the inspection cycle by combining IoT monitoring data (including daily operating parameters of equipment, material characteristics of equipment components, characteristics of the container medium, and environmental data). Compared with traditional inspection with a fixed cycle, it is better able to cope with variable risks such as material fatigue caused by diurnal temperature differences and secondary disasters caused by earthquakes (such as pipeline displacement caused by landslides), and has dynamic adaptability.

[0045] In summary, this invention can be widely applied in the field of testing. Attached Figure Description

[0046] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0047] Figure 1 This is a schematic diagram of a method flow provided in an embodiment of the present invention. Detailed Implementation

[0048] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0049] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0050] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0051] Currently, existing RBI methods have significant limitations for special operating conditions at high altitudes and low temperatures: 1) General models do not consider high-altitude pressure correction coefficients (e.g., BOG generation rate calculation deviation > 15%), leading to distorted assessment of leakage consequences; 2) The standard environmental load spectrum is mismatched with the actual temperature fluctuations (daily range 15℃) under special operating conditions, resulting in a pipeline stress fatigue life prediction error of up to 25%; 3) Static risk classification mechanisms are difficult to adapt to dynamic risk mutations caused by sudden extreme weather events at high altitudes. Therefore, it is urgent to construct a localized RBI model that integrates real-time environmental feedback for special operating conditions at high altitudes and low temperatures. By considering the relationship between altitude, temperature difference changes, earthquakes, and equipment risks, this model can provide relatively scientific decision support for the safety management of LNG equipment in high-altitude and low-temperature environments. This invention provides a risk-based inspection method for pressure-bearing equipment at LNG refueling stations in high-altitude areas. The method includes: acquiring daily operating parameters, material properties of the equipment components, characteristics of the containing medium, and environmental data of the pressure-bearing equipment at the LNG refueling station to be tested in the high-altitude area; inputting the acquired parameters into a pre-constructed RBI (Risk-Based Inspection) quantification model of the pressure-bearing equipment at the LNG refueling station to obtain the failure probability and severity of consequences of the pressure-bearing equipment; determining the risk level of the pressure-bearing equipment based on the obtained failure probability and severity of consequences; and conducting corresponding inspections of the pressure-bearing equipment based on the risk level and a pre-specified inspection plan. This invention constructs a multi-factor coupled model by integrating high-altitude air pressure, temperature fluctuation, and seismic risk parameters. A typical 60m section of pressure-bearing equipment in an LNG refueling station is used as an example. 3 Validation of cryogenic storage tanks shows that the method of this invention can improve the accuracy of risk classification to a certain extent, shorten the inspection cycle and reduce maintenance costs within a controllable risk range. This invention overcomes the limitations of traditional RBI in static assessment in the high-altitude environment of Linxia, ​​and realizes real-time correlation between risk and dynamic environmental parameters.

[0052] Example 1

[0053] like Figure 1 As shown, this embodiment provides a risk-based inspection method for pressure-bearing equipment in LNG refueling stations in plateau areas, including the following steps:

[0054] 1) Based on the characteristics of high altitude, large temperature difference, and earthquake risk, a quantitative RBI model of the pressure-bearing equipment of LNG refueling stations in plateau areas is pre-constructed, specifically as follows:

[0055] 1.1) Based on the characteristics of high altitude, large temperature difference, and earthquake risk, the failure probability calculation equation of the RBI quantitative model of LNG refueling station pressure equipment in plateau areas is constructed:

[0056] P of =α·σ corr ·K H ·t·β·N ΔT ·∈ fatigue ·γ·PGA·S geo (1)

[0057] Among them, P of σ represents the failure probability. corr The corrosion rate (mm / a) is expressed by the plateau-corrected equation σ. corr =0.12·e 0.003H ·10 -3 Calculate, where H is the altitude (m) of the location where the equipment will be used; K H The altitude correction factor, with a value of 1.0 + 0.002(H-2000), reflects the effect of low-oxygen environment on material brittleness; t is time (years); N ΔT The annual temperature range cycle number is calculated based on meteorological statistics under special working conditions. The percentage of days with a diurnal temperature range ≥15℃ is 43%, therefore N... ΔT It can take the value 157; ∈ fatigue The single-cycle thermal stress damage factor is taken as 5 × 10⁻⁶. -5 (Stainless steel material); PGA is the peak ground acceleration, using the design ground motion parameters with a 50-year exceedance probability of 10%; S geo α is the geological amplification factor, which can be set to 1.2; α, β, and γ are weighting coefficients, which are calibrated by Monte Carlo simulation to be α = 0.6, β = 0.3, and γ = 0.1.

[0058] First, it is clarified that the main damage modes of LNG refueling station pressure equipment in plateau areas are stress corrosion cracking and corrosion thinning under conditions of high altitude, large temperature difference and earthquake. By using the failure probability calculation equation in the established model, the failure probability of LNG refueling station pressure equipment can be calculated.

[0059] 1.2) Constructing the consequence severity equation for the RBI quantification model of LNG refueling station pressure equipment in plateau areas:

[0060] C of =λ·Q leak ·C LNG ·F ignition ·R pop ·η·E env (2)

[0061] Among them, C of For the severity of the consequences; Q leak The leakage equivalent (kg / s) is determined by the equipment pressure rating (e.g., P for storage tanks). op ·0.012, P op (Operating pressure, unit MPa); C LNG The diffusion coefficient of methane can be taken as 2.4 × 10⁻⁶. -3 (Correction value for high-altitude hypoxic environment); F ignition For ignition probability, 0.3 can be used for open-air equipment and 0.7 for enclosed spaces; R pop E represents the population exposure coefficient, categorized by population density within a 500m radius (0.1-1.0). env Environmental sensitivity is classified according to the requirements of the "Environmental Impact Report Form for Construction Projects" (1.5 can be used for Class I protected areas and 0.8 for industrial areas); λ and η are weighting factors, which are determined by the analytic hierarchy process as λ = 0.7 and η = 0.3.

[0062] The consequences of failure are mainly categorized into safety consequences, economic consequences, and environmental consequences. Safety consequences include explosions caused by leaks; economic consequences include economic losses and repair / replacement costs resulting from equipment safety accidents; and environmental consequences include environmental damage caused by leaks. Safety consequences are the primary focus of failure consequences. Using the consequence severity equation in the model, the severity of consequences for pressure-bearing equipment in LNG refueling stations can be calculated.

[0063] The overall risk value of the pressure equipment at an LNG refueling station is related to the probability of failure and the severity of the consequences of that equipment failure.

[0064] 2) Obtain the daily operating parameters, material properties of the equipment, characteristics of the contained medium, and environmental data of the pressure equipment of the LNG refueling station to be tested in the plateau area, and input them into the pre-built RBI quantitative model of the pressure equipment of the LNG refueling station to obtain the failure probability and severity of consequences of the pressure equipment of the LNG refueling station to be tested.

[0065] Specifically, the daily operating parameters of the equipment include operating pressure, leakage equivalent and maintenance correction factor; the material properties of the equipment components include single temperature difference stress cycle damage factor and corrosion rate; the properties of the contained medium include methane diffusion coefficient and ignition probability; and the environmental data include the altitude of the equipment location, population exposure coefficient, environmental sensitivity, annual temperature difference cycle number, peak ground acceleration and geological amplification factor.

[0066] 3) Based on the obtained failure probability and severity of consequences, determine the risk level of the pressure-bearing equipment in the LNG refueling station under test, specifically as follows:

[0067] 3.1) Based on the obtained failure probability and severity of consequences, and based on the pre-set inspection implementation guidelines, determine the failure probability level and failure consequence level of the pressure equipment of the LNG refueling station to be tested in the plateau area.

[0068] Specifically, the pre-defined inspection implementation guidelines are GB / T26610.1~5—2022 "Risk-based Inspection Implementation Guidelines for Pressure Equipment Systems".

[0069] Specifically, the failure probability levels are divided into five levels: 1, 2, 3, 4, and 5. Among them, the failure probability level of level 1 has a failure probability range of 0.00000. <P of ≤0.0000918, the failure probability range for failure probability level 2 is 0.0000918. <P of ≤0.000306, the failure probability range for failure probability level 3 is 0.000306. <P of ≤0.00306, the failure probability range for failure probability level 4 is 0.00306. <P of ≤0.0306, the failure probability range for failure probability level 5 is 0.0306. <P of ≤1.00000, as shown in Table 1 below:

[0070] Table 1: Failure Probability Levels

[0071] Failure probability level <![CDATA[Consequence probability range (P of )]]> 1 <![CDATA[0.00000<P of ≤0.0000918]]> 2 <![CDATA[0.0000918<P of ≤0.000306]]> 3 <![CDATA[0.000306<P of ≤0.00306]]> 4 <![CDATA[0.00306<P of ≤0.0306]]> 5 <![CDATA[0.0306<P of ≤1.00000]]>

[0072] Specifically, the failure consequences are classified into five levels: A, B, C, D, and E. Among them, level A is the lowest level, with the severity of consequences ranging from C. of <1×10 -4 Level B is low-level, with a severity range of 1×10. -4 ≤C of <1×10 -3 Level C is medium severity, with a consequence severity range of 1×10-1. -3 ≤C of <1×10 -2Level D is high-level, with a severity range of 1×10. -2 ≤C of <1×10 -1 Level E is extremely high, with a severity range of C. of ≥1×10 -1 As shown in Table 2 below:

[0073] Table 2: Failure Consequence Levels

[0074]

[0075]

[0076] 3.2) Determine the risk level of the pressure equipment of the LNG refueling station under test based on the failure probability level and failure consequence level of the pressure equipment in the plateau area.

[0077] Specifically, the risk levels include high risk, medium-high risk, medium risk, and low risk.

[0078] Specifically, the risk level of the pressure-bearing equipment in the LNG refueling station to be tested can be determined in two ways:

[0079] Method 1: Based on the obtained failure probability level and failure consequence level, and combined with the actual operation situation, comprehensively assess the acceptable level of risk, and determine the risk level of the pressure equipment of the LNG refueling station to be tested based on the pre-set risk matrix.

[0080] Specifically, the risk matrix consists of five columns representing failure consequence levels (A, B, C, D, and E) and five behavior failure probability levels (1, 2, 3, 4, and 5). LNG refueling station pressure equipment with a failure consequence level of D or E and a failure probability level of 3, 4, or 5 is classified as high-risk. Other high-risk levels include: LNG refueling station pressure equipment with a failure consequence level of E and a failure probability level of 1 or 2; LNG refueling station pressure equipment with a failure consequence level of D and a failure probability level of 3 or 4; and LNG refueling station pressure equipment with a failure consequence level of C and a failure probability level of 4 or 5. LNG refueling station pressure equipment with a failure consequence level of A or B and a failure probability level of 5 is classified as medium-high risk; LNG refueling station pressure equipment with a failure consequence level of C or D and a failure probability level of 1 or 2, LNG refueling station pressure equipment with a failure consequence level of C and a failure probability level of 3, and LNG refueling station pressure equipment with a failure consequence level of A or B and a failure probability level of 4 is classified as medium risk; LNG refueling station pressure equipment with a failure consequence level of A or B and a failure probability level of 1, 2, or 3 is classified as low risk.

[0081] Method 2: Calculate the comprehensive risk value R = P based on the obtained failure probability level and failure consequence level. of ×C of Based on the pre-set risk classification principles and the calculated comprehensive risk value, the risk level of the pressure equipment in the LNG refueling station under test is determined.

[0082] Specifically, pre-defined risk classification principles include, for example, the API 581 risk inspection standard and the "Guideline for Risk-Based Inspection of Pressure Equipment Systems Part 4: Quantitative Analysis Method for Failure Probability" (GB / T26610.4-2022).

[0083] 4) Based on the risk level of the pressure-bearing equipment of the LNG refueling station to be tested and the pre-designated inspection plan, conduct corresponding inspections on the pressure-bearing equipment of the LNG refueling station to be tested, specifically as follows:

[0084] 4.1) Develop the corresponding inspection plan for each risk level.

[0085] Specifically, advanced equipment and complex technologies are used to conduct rigorous and focused inspections of high-risk or medium-to-high-risk LNG refueling station pressure equipment, thereby reducing the risk level of this equipment. Medium-risk LNG refueling station pressure equipment undergoes routine inspections. Low-risk LNG refueling station pressure equipment undergoes simplified inspections without shutting down the equipment, extending the inspection cycle and reducing inspection costs.

[0086] 4.2) Based on the pre-established inspection plan, conduct corresponding inspections on the pressure equipment of the LNG refueling station to be tested according to the risk level of the pressure equipment.

[0087] The following specific embodiments are used to verify the RBI quantitative model of the LNG refueling station pressure equipment constructed in this invention and to compare it with periodic inspections:

[0088] This example uses a 60m LNG refueling station in an industrial park in Linxia, ​​China. 3 The cryogenic storage tank was used as the model validation object. The constructed RBI (Responsive Inspection and Testing) quantitative model of the pressure-bearing equipment in an LNG refueling station was theoretically validated, and the validation results were compared and analyzed with those from traditional periodic inspections. The operating parameters of the cryogenic storage tank are: operating pressure 0.75 MPa, operating temperature -162℃, inner container material austenitic stainless steel (S30408), outer container material Q345R, and the insulation layer adopts a vacuum powder insulation structure. Located in a plateau region at an altitude of 2100m, the tank was put into operation in April 2022 and completed its first periodic inspection in March 2025 (safety status level 2, no significant defects).

[0089] Calculated:

[0090] Pof =α·σ corr ·K H ·t·β·N ΔT ·∈ fatigue ·γ·PGA·S geo =7.81658·10 -5

[0091] C of =λ·(Q leak ·C LNG ·F ignition ·R pop )+η·E env =5.4432·10 -7

[0092] R = P of ×C of =4.2547·10 -11

[0093] Based on the API 581 risk inspection standard and the risk classification principles of "Guidelines for Risk-Based Inspection of Pressure Equipment Systems Part 4: Quantitative Analysis Method for Failure Probability" (GB / T 26610.4-2022), the comprehensive risk value R = 4.2547·10 -11 The corresponding risk level is determined to be low, and a simplified test can be performed.

[0094] The risk level of the LNG cryogenic storage tank in this example is calculated and determined to be low risk using the model proposed in this invention. For a low risk level, the detection methods that this invention can employ without shutting down the equipment include:

[0095] ①Online inspection: (1) The wall thickness of the LNG cryogenic storage tank is measured by pulsed eddy current scanning once a year. The technical indicators are detection accuracy ±0.5mm and cold insulation penetration capability 200mm. (2) The vacuum degree of the interlayer is checked by infrared thermal imaging every quarter. When the temperature difference is >5℃, an alarm is triggered. The technical indicator is resolution 0.05℃. (3) The crack propagation signal is monitored in real time by acoustic emission detection. The technical indicator is positioning accuracy ±50mm. (4) Targeted sampling inspection: The sampling ratio is reduced to 5% according to GB / T 30578 (20% for routine inspection); the key areas are the gas phase interface section (corrosion sensitive area), the weld of the outer nozzle (stress concentration area) and the foundation settlement monitoring point. (5) Data-driven inspection optimization: Ultrasonic thickness measurement is used every 2 years to compare the online detection data with the corrosion model σ. corr =0.12·e 0.003H ·10 -3Calibration is performed; digital record management: a 3D visualization model is developed, integrating historical inspection data with real-time monitoring results, and automatically generating the equipment health index (HI).

[0096] ② Optimization of inspection items: (1) If the routine inspection item is vacuum degree test, the adjustment plan under the low risk level is to change it to infrared online monitoring (no shutdown). (2) If the routine inspection item is safety valve calibration, the adjustment plan under the low risk level is to extend it to 3 years / time (originally 1 year / time). (3) If the routine inspection item is airtightness test, the adjustment plan under the low risk level is to replace it with DCS leakage monitoring system.

[0097] ③ Triggered upgrade inspection: When online monitoring data suddenly changes (such as daily wall thickness reduction > 0.3 mm), LNG leakage rate > 10 ppm, or when an earthquake (≥ 5 magnitude) or extreme weather occurs, a comprehensive inspection will be initiated immediately.

[0098] If the operational risk level of the LNG cryogenic storage tank is determined to be medium risk level through the model of this invention, the detection methods that this invention can employ for medium risk level include:

[0099] ① Inspection method combination: (1) Comprehensive inspection after opening the tank: Inspection focus: Magnetic particle testing (MT) or penetrant testing (PT) of the weld seams (circumferential seams and longitudinal seams) of the inner wall of the storage tank, with a coverage rate of ≥30%; bottom plate corrosion status scanning (using magnetic flux leakage testing MFL or ultrasonic thickness measurement UT), focusing on checking the risk of cracks in the welded areas with unequal wall thickness; verification of the effectiveness of cathodic protection at the connection between the bottom edge plate and the foundation. Execution conditions: Production must be stopped, the tank cleaned and the inert gas replaced. (2) Online monitoring and local inspection: Acoustic emission real-time monitoring: Continuous acoustic monitoring of the bottom of the tank under operating conditions to capture the signal of active defect expansion; Guided wave detection (GW): Long-distance corrosion scanning of the connection between the tank wall and the pipeline, covering areas that are difficult to access; Infrared thermal imaging: Monitoring the integrity of the insulation layer and identifying stress concentration areas caused by temperature difference (such as high-risk points with a circumferential temperature difference >40℃).

[0100] ② Verification of key process parameters: (1) Material performance testing: Samples of 304 / 304L stainless steel base material and weld were taken and Charpy impact test was conducted at -196℃ to verify the toughness decay level; fatigue cycle test (strain amplitude ≤0.8%) was conducted to assess the failure risk of liquid ingress times (>4,500 times) within the design life. (2) High-altitude environment adaptability correction: Corrosion model σ was applied. corr =0.12e 0.003H ·10 -3 (H represents altitude in meters), dynamically adjust the inspection cycle; combine the atmospheric pressure at an altitude of 2000 meters (approximately 0.08 MPa) to verify the safety valve opening pressure and vacuum protection system.

[0101] ③ Inspection cycle and risk management are shown in Table 3 below:

[0102] Table 3: Inspection Cycle and Risk Management for Medium-Risk Areas

[0103]

[0104] ④ Special requirements for high-altitude areas: (1) Special inspection of the cold insulation system: Due to the large temperature difference between day and night on the plateau, additional tests are required: the distribution of dew point on the outer tank wall (to avoid local low temperature causing material brittleness); the sealing of the vacuum interlayer to ensure that the vacuum degree is ≤5Pa1. (2) Seismic load verification: The seismic fortification intensity of Linxia area is 7 degrees, and the seismic stress amplification factor of the tank support structure needs to be verified.

[0105] If the operational risk level of the LNG cryogenic storage tank is calculated to be medium-high risk level using the model of this invention, the detection methods that this invention can employ for medium-high risk level include:

[0106] ① The combination of test methods is shown in Table 4 below:

[0107] Table 4: Combination of testing methods for medium- and high-risk cases

[0108]

[0109] ②Adaptation to high-altitude environment: (1) Corrosion correction: Applying the corrosion model σ corr =0.15e 0.004H ·10 -3 , dynamically adjust the testing cycle (e.g., shorten the original cycle of 3 years to 2 years); (2) Seismic verification: check the pre-tightening force of the support bolts according to the seismic intensity of 7 degrees, and increase the torque by 15%; (3) Material testing: take samples for impact testing at -196℃, and trigger a replacement warning when the elongation rate is <14%.

[0110] ③ Risk control thresholds are shown in Table 5 below:

[0111] Table 5: Risk Management Thresholds for Medium- and High-Risk Areas

[0112] index Limits for medium- and high-risk actions measure Wall thickness corrosion residue ≤60% of design thickness Immediately stop using and repair welding Vacuum attenuation rate >5Pa / month Start the interlayer vacuum system for maintenance Acoustic emission event count >50 times / 24h Can opening, re-inspection, and 3D scanning

[0113] If the operational risk level of the LNG cryogenic storage tank is determined to be high-risk based on the model of this invention, the detection methods that this invention can employ for high-risk levels include:

[0114] ①Immediately open the tank for comprehensive inspection (forced shutdown to be carried out): (1) 100% non-destructive testing of the inner wall: full coverage of weld seams with magnetic particle testing (MT) and penetrant testing (PT), focusing on checking for low-temperature fatigue cracks and heat-affected zone defects in circumferential welds / longitudinal welds; full scanning of the tank bottom using magnetic flux leakage testing (MFL), mandatory replacement of areas with corrosion rate > 0.5 mm / year; safety valve opening pressure is checked according to the high-altitude correction value (standard value × 1.2). (2) Material performance limit test: samples are taken for Charpy impact test at -196℃, material replacement is triggered when the impact energy ≤ 27J; vacuum jacket helium mass spectrometry leak detection, immediate shutdown and repair if vacuum degree > 3Pa.

[0115] ② Enhanced online real-time monitoring, as shown in Table 6 below:

[0116] Table 6: Enhanced Online Real-Time Monitoring for High-Risk Areas

[0117]

[0118]

[0119] ③ Special risk management in high-altitude areas: (1) Corrosion prevention and control: applying the corrosion model σ corr =0.18e 0.005H ·10 -3 Dynamically adjust the detection cycle (the original cycle is shortened by 60%); monitor the cathodic protection potential: start system maintenance when the polarization potential is <-850mV. (2) Seismic protection: check the preload of the support bolts according to the seismic intensity of 7 degrees (torque increased by 20%); finite element analysis of the stress concentration factor of the bottom edge plate of the tank (strengthen when >3.0).

[0120] ④ High-risk handling standards: (1) Immediate shutdown conditions: detection of penetrating cracks or deep pit corrosion (depth > wall thickness 50%); vacuum degree > 10 Pa and continues to deteriorate; acoustic emission energy release rate > 500 J / h.

[0121] Compared with traditional periodic testing, the advantages of the RBI method are reflected in the following aspects:

[0122] Inspection cycle optimization: Under low-risk levels, the inspection cycle can be extended from the traditional fixed 4 years to 5 years, reducing downtime losses by about 30%.

[0123] The testing strategy is refined: the embrittlement coefficient of materials is modified for the low-oxygen environment of high altitude, and priority is given to testing welds (magnetic particle sampling ≤10%) and the sealing of vacuum insulation layer to avoid the waste of resources from comprehensive testing.

[0124] Dynamic risk monitoring: By monitoring temperature difference cycle (threshold ≥15℃) and vacuum degree (alarm value ≤0.08Pa) online, potential defects are warned in real time, making up for the periodic blind spots of traditional inspection.

[0125] Compared to traditional periodic inspections, the RBI method significantly reduces operation and maintenance costs while ensuring safety by quantifying risks (such as corrosion rates and seismic parameters) and employing dynamic adjustment strategies. This invention theoretically verifies the feasibility of applying the RBI method in complex high-altitude environments and can provide a scientific basis for the full life-cycle management of similar pressure vessels.

[0126] Example 2

[0127] This embodiment provides a risk-based inspection system for pressure-bearing equipment at LNG refueling stations in high-altitude areas, including:

[0128] The data acquisition module is used to acquire the daily operating parameters of the pressure-bearing equipment of the LNG refueling station under test in the plateau area, the material characteristics of the equipment components, the characteristics of the container medium, and environmental data.

[0129] The RBI quantification module is used to input the acquired daily operating parameters of the equipment, the material characteristics of the equipment components, the characteristics of the container medium, and environmental data into the pre-built RBI quantification model of the pressure equipment of the LNG refueling station, so as to obtain the failure probability and the severity of the consequences of the pressure equipment of the LNG refueling station under test.

[0130] The risk level determination module is used to determine the risk level of the pressure equipment in the LNG refueling station under test based on the obtained failure probability and the severity of the consequences.

[0131] The inspection determination module is used to conduct corresponding inspections on the pressure equipment of the LNG refueling station under test according to the risk level and the pre-specified inspection plan.

[0132] The system provided in this embodiment is used to execute the above-described method embodiments. For specific processes and details, please refer to the above embodiments, which will not be repeated here.

[0133] Example 3

[0134] This embodiment provides a processing device corresponding to the risk-based inspection method for pressure-bearing equipment of LNG refueling stations in plateau areas provided in Embodiment 1. The processing device can be applied to the processing devices of the client, such as mobile phones, laptops, tablets, desktop computers, etc., to execute the method of Embodiment 1.

[0135] The processing device includes a processor, a memory, a communication interface, and a bus. The processor, memory, and communication interface are connected via the bus to enable communication between them. The memory stores a computer program that can run on the processing device. When the processing device runs the computer program, it executes the risk-based inspection method for pressure-bearing equipment in LNG refueling stations in high-altitude areas provided in Embodiment 1.

[0136] In some implementations, the memory may be high-speed random access memory (RAM), and may also include non-volatile memory, such as at least one disk storage device.

[0137] In other implementations, the processor can be any type of general-purpose processor, such as a central processing unit (CPU) or a digital signal processor (DSP), and there is no limitation here.

[0138] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0139] Those skilled in the art will understand that the structure of the above-described computing device is only a partial structure related to the present invention and does not constitute a limitation on the computing device to which the present invention is applied. A specific computing device may include more or fewer components, or combine certain components, or have different component arrangements.

[0140] Example 4

[0141] This embodiment provides a computer program product corresponding to the risk-based inspection method for pressure-bearing equipment of LNG refueling stations in plateau areas provided in Embodiment 1. The computer program product may include a computer-readable storage medium on which computer-readable program instructions for executing the risk-based inspection method for pressure-bearing equipment of LNG refueling stations in plateau areas described in Embodiment 1 are loaded.

[0142] A computer-readable storage medium can be a tangible device that holds and stores instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any combination thereof.

[0143] The computer-readable storage medium provided in the above embodiments has a similar implementation principle and technical effect to the above method embodiments, and will not be described again here.

[0144] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0145] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0146] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0147] The above embodiments are only used to illustrate the present invention. The structure, connection method and manufacturing process of each component can be varied. All equivalent transformations and improvements made on the basis of the technical solution of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A risk-based inspection method for pressure-bearing equipment in LNG refueling stations in plateau areas, characterized in that, include: To obtain daily operating parameters, material properties of the equipment, properties of the contained medium, and environmental data of the pressure-bearing equipment of the LNG refueling station to be tested in the plateau region; The acquired daily operating parameters of the equipment, the material properties of the equipment components, the properties of the container medium, and environmental data are input into the pre-built RBI quantitative model of the pressure equipment of the LNG refueling station to obtain the failure probability and the severity of the consequences of the pressure equipment of the LNG refueling station under test. Based on the obtained failure probability and severity of consequences, the risk level of the pressure equipment in the LNG refueling station under test is determined; Based on the risk level of the pressure-bearing equipment of the LNG refueling station to be tested and the pre-specified inspection plan, the corresponding inspection is carried out on the pressure-bearing equipment of the LNG refueling station to be tested.

2. The risk-based inspection method for pressure-bearing equipment in LNG refueling stations in plateau areas as described in claim 1, characterized in that, The RBI quantitative model for the pressure-bearing equipment of the LNG refueling station is established based on the characteristics of high altitude, large temperature difference and earthquake risk, and includes failure probability calculation equation and consequence severity equation.

3. The risk-based inspection method for pressure-bearing equipment in LNG refueling stations in plateau areas as described in claim 2, characterized in that, The equation for calculating the failure probability is: P of =a·s corr ·K H ·t·β·N ΔT ·∈ fatigue ·c·PGA·S geo Among them, P of σ represents the failure probability. corr H represents the corrosion rate; H represents the altitude of the equipment's location; K represents the corrosion rate. H t is the altitude correction factor; t is time; N ΔT The annual temperature range cycle number; ∈ fatigue The single-cycle thermal stress damage factor is represented by S; PGA is the peak ground acceleration; S geo α is the geological amplification factor; β and γ are weighting coefficients. The severity equation for consequences is: C of =λ·Q leak ·C LNG ·F ignition ·R pop ·the·E env Among them, C of For the severity of the consequences; Q leak Leakage equivalent; C LNG F is the diffusion coefficient of methane; ignition R represents the ignition probability. pop E represents the population exposure coefficient. env Environmental sensitivity; λ and η are weighting factors; The risk index matrix equation is as follows: R=P of ×C of ×K maintenance Where R is the overall risk value; K maintenance For maintenance and repair correction factors.

4. The risk-based inspection method for pressure-bearing equipment in LNG refueling stations in plateau areas as described in claim 1, characterized in that, The equipment's daily operating parameters include operating pressure, leakage equivalent, and maintenance correction factor; the material properties of the equipment components include single-cycle thermal stress damage factor and corrosion rate; the properties of the contained medium include methane diffusion coefficient and ignition probability; and the environmental data include the altitude of the equipment's location, population exposure coefficient, environmental sensitivity, annual thermal cycle count, peak ground acceleration, and geological amplification factor.

5. A risk-based inspection method for pressure-bearing equipment in LNG refueling stations in plateau areas as described in claim 1, characterized in that, The risk level of the pressure equipment at the LNG refueling station under test is determined based on the obtained failure probability and severity of consequences, including: Based on the obtained failure probability and severity of consequences, and in accordance with the pre-set inspection implementation guidelines, the failure probability level and failure consequence level of the pressure equipment of the LNG refueling station under test in the plateau area are determined. Based on the failure probability level and failure consequence level of the pressure-bearing equipment of the LNG refueling station under test in the plateau region, the risk level of the pressure-bearing equipment of the LNG refueling station under test is determined, including high risk level, medium-high risk level, medium risk level and low risk level.

6. A risk-based inspection method for pressure-bearing equipment in LNG refueling stations in plateau areas as described in claim 5, characterized in that, The determination of the risk level of the pressure-bearing equipment in the LNG refueling station to be tested includes: Based on the obtained failure probability level and failure consequence level, and combined with the actual operation, the acceptable level of risk is comprehensively assessed. Based on the pre-set risk matrix, the risk level of the pressure equipment of the LNG refueling station under test is determined. The columns of the risk matrix represent the failure consequence level, and the behavior of the risk matrix represents the failure probability level. Alternatively, based on the obtained failure probability level and failure consequence level, calculate the comprehensive risk value, and determine the risk level of the pressure equipment of the LNG refueling station to be tested according to the pre-set risk classification principle.

7. A risk-based inspection method for pressure-bearing equipment in LNG refueling stations in plateau areas as described in claim 1, characterized in that, The process involves conducting corresponding inspections of the pressure-bearing equipment at the LNG refueling station under test, based on the risk level and a pre-designated inspection plan. This includes: Develop corresponding inspection plans for each risk level; Based on the pre-established inspection plan, and according to the risk level of the pressure equipment of the LNG refueling station to be tested, the corresponding inspection is carried out on the pressure equipment of the LNG refueling station to be tested.

8. A risk-based inspection system for pressure-bearing equipment in LNG refueling stations in high-altitude areas, characterized in that, include: The data acquisition module is used to acquire the daily operating parameters, material properties of the equipment, properties of the container medium, and environmental data of the pressure-bearing equipment of the LNG refueling station to be tested in the plateau region. The RBI quantification module is used to input the acquired daily operating parameters of the equipment, the material characteristics of the equipment components, the characteristics of the container medium, and environmental data into the pre-built RBI quantification model of the pressure equipment of the LNG refueling station, so as to obtain the failure probability and the severity of the consequences of the pressure equipment of the LNG refueling station under test. The risk level determination module is used to determine the risk level of the pressure equipment in the LNG refueling station under test based on the obtained failure probability and severity of consequences. The inspection determination module is used to conduct corresponding inspections on the pressure equipment of the LNG refueling station under test according to the risk level and the pre-specified inspection plan.

9. A processing device, characterized in that, It includes computer program instructions, wherein when the computer program instructions are executed by a processing device, they are used to implement the steps corresponding to the risk-based inspection method for pressure-bearing equipment of LNG refueling stations in plateau areas as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions, wherein when executed by a processor, the computer program instructions are used to implement the steps corresponding to the risk-based inspection method for pressure-bearing equipment of LNG refueling stations in plateau areas as described in any one of claims 1-7.

Images