Calculation method of natural gas long-distance pipeline explosion fragment ejection damage probability
By calculating the ejection extreme value and hit probability model of explosion debris in natural gas long-distance pipelines, the probability of ejection damage to the target is accurately calculated, which solves the problem that is difficult to accurately calculate in the existing technology and provides a more reliable safe distance Assessment to help control the risk of failure accidents in long-term natural gas pipelines.
Patent Information
- Application Number
- CN202411480844.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2025-02-11
AI Technical Summary
The prior art is difficult to accurately calculate the probability of ejection damage of explosion debris in long-distance natural gas pipelines, and numerical simulation methods have difficulties in the actual application of engineering, and the target volume and other factors are not considered, so the simulation results are difficult to form a reference for practical problems.
By determining the number of explosion debris in a long-distance pipeline, defining the horizontal launch angle of the pipeline explosion debris and the target's tangent cube area, calculating the ejection extreme value of the explosion debris, obtaining the mapping relationship of the debris causing ejection damage to the target, and according to the natural gas long-distance pipeline, the The probability model of the explosion debris hits the target, calculates the probability of the explosion debris hitting the target.
The accurate calculation of the probability of catapult damage of explosion debris in natural gas long-distance pipelines is achieved, and factors such as the target volume are taken into account, providing a more reliable safety distance assessment to help control the risk of failure accidents in natural gas long-distance pipelines.
Smart Images
Figure CN119416485A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of natural gas long-distance pipeline safety, and in particular relates to a method for calculating the probability of ejection damage caused by explosion fragments in a natural gas long-distance pipeline. Background Art
[0002] As a clean energy source in the 21st century, the construction scale of long-distance natural gas pipelines continues to grow. In order to meet the supply and demand of natural gas, long-distance pipelines are developing in the direction of high pressure, large diameter and long distance. According to the "China Natural Gas Development Report (2024)", the total mileage of China's long-distance natural gas pipelines will reach 124,000 kilometers in 2023, an increase of more than 4,000 kilometers over the previous year.
[0003] During daily operation, natural gas long-distance pipelines are subject to corrosion, third-party damage, geological disasters, operational errors and other factors, which can cause pipeline failure and rupture, resulting in natural gas leakage, which can easily lead to fires, explosions and other malicious incidents, greatly threatening the safety of people and buildings around the pipelines. When the pipeline fails, high-pressure natural gas is ejected at a very high speed, causing the pipeline to break, and pipeline fragments are ejected at high speed from the explosion point, causing serious damage to buildings and people around the pipeline.
[0004] In summary, the probability of damage from explosion fragments ejection is of great significance for controlling the risk of failure accidents of long-distance natural gas pipelines and designing the safety distance around the pipeline. The probability of damage from explosion fragments ejection in long-distance natural gas pipelines can be determined by experiments or numerical simulation methods. The experimental method is difficult to carry out due to the high risk factor and experimental cost, while the numerical simulation method is difficult to use in actual engineering, and does not consider factors such as the target volume. The simulation results are difficult to form a reference for actual problems. Summary of the invention
[0005] In view of the above problems, the present invention takes into account the position of the target and the circumscribed cube area of the target, and provides a method for calculating the probability of catapulting damage caused by fragments of a natural gas long-distance pipeline explosion by counting the results of catapulting damage caused by a single fragment to the target.
[0006] The present invention is achieved through the following technical solutions:
[0007] The above-mentioned method for calculating the probability of damage caused by explosion fragments ejected from a long-distance natural gas pipeline comprises the following steps:
[0008] Step 1, determining the number of explosion fragments in the long-distance pipeline;
[0009] Step 2, defining the horizontal emission angle of pipeline explosion fragments and the circumscribed cube area of the target;
[0010] Step 3, calculating the ejection extreme value of the explosion fragments, and obtaining the mapping relationship of the ejection damage caused by the fragments to the target;
[0011] Step 4: Calculate the probability of damage caused by explosion fragments to the target based on the probability model of explosion fragments hitting the natural gas long-distance pipeline.
[0012] In step 1, the relationship between the inner diameter of the pipeline and the number of explosion fragments is obtained based on case statistics as shown in Table 1: Table 1 Number of explosion fragments of long-distance pipelines
[0013] Pipe inner diameter (mm) Number of fragments 250～500 3 500～750 6 750～1000 9 More than 1000 12
[0014] In step 2, defining the horizontal emission angle of pipeline explosion fragments and the tangential area of the target includes the following steps:
[0015] (1) Define the horizontal emission angle of pipeline explosion fragments
[0016] With the explosion point of the pipeline as the origin O, the pipeline line as the X-axis, the normal direction of the pipeline as the Y-axis, and the gravity direction as the Z-axis, the horizontal emission angle θ of the fragments is calculated according to formula (1):
[0017]
[0018] Where θ is the angle between the projection of the initial velocity of the explosion fragments on the XOY plane and the X-axis, in degrees; l is the normal distance from the pipeline explosion point to the target object, in meters; x+ and x- are the maximum and minimum boundary values of the target object in the X-axis direction, in meters;
[0019] (2) Define the circumscribed cube area of the target
[0020] The X-axis is translated vertically along the Y-axis direction to be tangent to the surface of the target object, and the minimum and maximum boundary values of the target in the X-axis direction are determined to be x- and x+ respectively; the Y-axis is translated horizontally along the X-axis direction to be tangent to the surface of the target object, and the minimum and maximum boundary values of the target object in the Y-axis direction are determined to be y- and y+ respectively; the Z-axis is translated along the horizontal plane to contact the surface of the target object, so as to determine the maximum boundary value z+ of the target object in the Z-axis direction; the circumscribed cube area of the target is the three-dimensional space enclosed by the three coordinate ranges of X, Y, and Z (x-, x+), (y-, y+), and (0, z+).
[0021] In step 3, the mapping relationship of the collision damage caused by the fragments to the target is obtained according to the projectile extreme value of the explosion fragments. The projectile extreme value of the explosion fragments is calculated according to Table 2:
[0022] Table 2 Calculation formula for the maximum projection value of explosion fragments
[0023] direction Projectile extreme value calculation formula X <![CDATA[x max =4790.43cosθ]]> Y <![CDATA[y max =4790.43sinθ]]> Z <![CDATA[z max =1615.29]]>
[0024] Where: θ is the horizontal emission angle of the debris, in degrees;
[0025] The mapping relationship of the catapulting damage caused by explosion fragments to the target is as follows:
[0026]
[0027] In the formula, x max ,y max , z max is the ejection extreme value of the fragment in the X, Y, and Z axis directions; when the ejection extreme values of the fragment in each direction are all outside the target circumscribed cube area, n is 0; when the ejection extreme values in any two directions are within the target circumscribed cube area, n is 1.
[0028] In step 4, according to the probability model of explosion fragments hitting the natural gas long-distance pipeline, the probability of the explosion fragments catapulting damage to the target is calculated according to formula (3):
[0029]
[0030] Where N sum is the number of explosion fragments; n depends on the mapping relationship of the ejection damage caused by the fragments to the target; processing the calculation results, determining the impact of each fragment on the target, the collision probability P can be obtained imp . BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 A flow chart of a method for calculating the probability of damage from the ejection of explosion fragments from a long-distance natural gas pipeline provided by the present invention.
[0032] Figure 2 This is a probability distribution diagram of explosion fragments damaging different targets obtained by applying the example of the present invention. DETAILED DESCRIPTION
[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0034] Step 1: Determine the number of explosion fragments in the long-distance pipeline.
[0035] Step 2: Define the horizontal emission angle of pipeline explosion fragments and the tangential area of the target.
[0036] Step 3: Calculate the ejection extreme value of the explosion fragments to obtain the mapping relationship of the ejection damage caused by the fragments to the target.
[0037] Step 4: Calculate the probability of damage caused by explosion fragments to the target based on the probability model of explosion fragments hitting the natural gas long-distance pipeline.
[0038] Specific implementation cases
[0039] 5000m 3 Spherical tank, 2000m 3 Spherical tank and 400m 3 The probability of being hit by Φ914×9.1mm pipeline explosion fragments was calculated for spherical tanks and personnel. The size of the spherical tank target was determined with reference to GB / T 17261-2011 "Types and basic parameters of steel spherical storage tanks", and the size of the personnel target was determined according to GB / T 10000-2023 "Human body dimensions of Chinese adults". The specific sizes of the spherical tank and personnel targets are shown in Table 1.
[0040] Table 1 Detailed dimensions of spherical tanks and personnel targets
[0041]
[0042] according to Figure 1 The steps shown in the figure are as shown in Table 2.
[0043] Table 2 Parameters for determining the probability of blast fragment ejection damage
[0044]
[0045] according to Figure 1 The steps shown in the figure determine the horizontal launch angle of the fragments according to the normal distance from the explosion point to the target object, calculate the fragment ejection extreme value, obtain the mapping relationship between the ejection extreme value and the circumscribed area of different targets, and determine whether a single fragment will produce ejection collision with different targets. Then, the ejection damage probability of the explosion fragments is calculated according to the fragment impact model. The results are as follows: Figure 2 shown.
[0046] from Figure 2 The hit probability results show that if the tank has a hit probability less than 1×10 -2 For safety standards, 5000m 3 The safety distance of the spherical tank is 75m and 2000m 3 and 400m 3 The safe distance of the spherical tank is 50m. If the probability of hitting is less than 1×10 -6 For safety standards, the safety distance is 75m.
Claims
1. A method for calculating the probability of damage from the ejection of explosion fragments in a long-distance natural gas pipeline, characterized in that: Considering the position distance and circumscribed cube area of the targets around the pipeline, the hit probability of explosion fragment ejection damage is calculated, including the following steps: Step 1, determining the number of explosion fragments in the long-distance pipeline; Step 2, defining the horizontal launch angle of pipeline explosion fragments and the circumscribed cube area of the target; Step 3, calculating the ejection extreme value of the fragments to obtain the mapping relationship of the ejection damage caused by the fragments to the target; Step 4: Calculate the probability of damage caused by explosion fragments to the target based on the probability model of explosion fragments hitting the natural gas long-distance pipeline.
2. The method for calculating the probability of damage from the ejection of explosion fragments in a long-distance natural gas pipeline according to claim 1, characterized in that: The number of explosion fragments of the long-distance pipeline determined in step 1 is as follows: Table 1 Number of explosion fragments in long-distance pipelines 3. The method for calculating the probability of damage from the ejection of explosion fragments in a long-distance natural gas pipeline according to claim 1, characterized in that: Defining the horizontal emission angle of pipeline explosion fragments and the circumscribed cube area of the target in step 2 includes the following steps: (1) Define the horizontal emission angle of explosion fragments: With the explosion point of the pipeline as the origin O, the pipeline line as the X-axis, the normal direction of the pipeline as the Y-axis, and the gravity direction as the Z-axis, the horizontal emission angle θ of the fragments is calculated according to formula (1): Where θ is the angle between the projection of the initial velocity of the explosion fragments on the XOY plane and the X-axis, in degrees; l is the normal distance from the pipeline explosion point to the target object, in meters; x+ and x- are the maximum and minimum boundary values of the target object in the X-axis direction, in meters; (2) Define the circumscribed cube area of the target: The X-axis is translated vertically along the Y-axis direction to be tangent to the surface of the target object, and the minimum and maximum boundary values of the target in the X-axis direction are determined to be x- and x+ respectively; the Y-axis is translated horizontally along the X-axis direction to be tangent to the surface of the target object, and the minimum and maximum boundary values of the target object in the Y-axis direction are determined to be y-y+ respectively; the Z-axis is translated along the horizontal plane to contact the surface of the target object, so as to determine the maximum boundary value Z+ of the target object in the Z-axis direction; the circumscribed cube area of the target is the three-dimensional space enclosed by the three coordinate ranges of X, Y, and Z (x-, x+), (y-, y+), and (0, z+).
4. The method for calculating the probability of damage from the ejection of explosion fragments from a long-distance natural gas pipeline according to claim 1, characterized in that: The mapping relationship of the collision damage caused by the fragments to the target obtained according to the ejection extreme value of the explosion fragments in step 3 includes the following steps: The maximum projection value of explosion fragments is calculated according to Table 2: Table 2 Calculation formula for the maximum projection value of explosion fragments Where: θ is the horizontal emission angle of the debris, in degrees; The mapping relationship of the catapulting damage caused by explosion fragments to the target is as follows: In the formula, x max ,y max , z max is the ejection extreme value of the fragment in the X, Y, and Z axis directions; when the ejection extreme values of the fragment in each direction are all outside the target circumscribed cube area, n is 0; when the ejection extreme values in any two directions are within the target circumscribed cube area, n is 1.
5. The method for calculating the probability of damage from the ejection of explosion fragments in a long-distance natural gas pipeline according to claim 1, characterized in that: In step 4, according to the natural gas long-distance pipeline explosion fragment hit probability model, the method for calculating the probability of the explosion fragments ejecting damage to the target is as follows: Where N sum is the number of explosion fragments; n depends on the mapping relationship of the ejection damage caused by the fragments to the target; processing the calculation results, determining the hit of each fragment on the target, the collision probability P can be obtained imp .