Gas power plant explosion dangerous area risk assessment method based on environmental characteristics

Abstract

The invention discloses a gas power plant explosion dangerous area risk assessment method based on environmental characteristics, and relates to the technical field of risk assessment, and the method comprises the steps: calculating the gas leakage possibility and the gas leakage speed; obtaining at least one vulnerable position set; the gas accumulation speed is obtained; obtaining a fire source occurrence coefficient; based on the critical condition of gas detonation, the fire source occurrence coefficient, the gas accumulation speed, the gas leakage possibility and the gas leakage speed, the explosion risk value of the explosion dangerous area is obtained through calculation; and obtaining a value range of the historical explosion risk values based on the historical data, and forming a risk rating standard based on the value range of the historical explosion risk values. By combining vulnerable positions, calculating the possibility of gas leakage and the speed of gas leakage, analyzing the space structure and the ventilation condition of an explosion dangerous area, and estimating the air flow condition according to the environmental characteristics in the gas power plant, the risk of explosion can be described more accurately.

Description

Technical Field

[0001] The present invention relates to the technical field of risk assessment, and specifically relates to a risk assessment method for explosion - prone areas in gas - fired power plants based on environmental characteristics. Background Art

[0002] Gas - fired power plants use gas - fired generator sets for power generation. The working principle of a gas - fired generator set is to burn fuels such as natural gas, coal gas, and biogas in a gas engine to generate high - temperature and high - pressure gas, which drives the piston to move, thereby converting it into mechanical energy and then into electrical energy output through a generator.

[0003] When a gas - fired power plant generates electricity, since gas needs to be transported, due to corrosion, and because the gas transmission is at high pressure, cracks are likely to appear in places where the pipe wall is thin, and thus leakage may occur, which may lead to an explosion. However, whether an explosion occurs depends on the gas concentration, and the gas concentration is related to the environment. Existing technologies usually only evaluate the explosion from the perspective of leakage, and the risk characterization of the explosion is not accurate enough. Summary of the Invention

[0004] To solve the above - mentioned technical problems, a risk assessment method for explosion - prone areas in gas - fired power plants based on environmental characteristics is provided, and this technical solution solves the problems raised in the above - mentioned background art.

[0005] To achieve the above - mentioned purpose, the technical solution adopted by the present invention is as follows: A risk assessment method for explosion - prone areas in gas - fired power plants based on environmental characteristics, including: Obtain at least one gas transmission pipeline of the gas - fired power generation equipment in the gas - fired power plant, identify the pipe wall thickness of the gas transmission pipeline to obtain at least one vulnerable position and the parameters of the vulnerable position, and obtain the position coordinates of the vulnerable position; Calculate the gas leakage probability and gas leakage speed according to the parameters of the vulnerable position; Based on the position attributes of the vulnerable positions, perform a merging process on the vulnerable positions to obtain at least one set of vulnerable positions; Form an explosion - prone area based on the set of vulnerable positions, analyze the spatial structure and ventilation conditions of the explosion - prone area to obtain the gas accumulation speed; Analyze the possibility of the presence of a fire source in the explosion - prone area to obtain the fire source appearance coefficient; Based on historical data, obtain the critical conditions for gas detonation. Based on the critical conditions for gas detonation, the fire source appearance coefficient, the gas accumulation speed, the gas leakage probability, and the gas leakage speed, calculate the explosion risk value of the explosion - prone area; Based on historical data, obtain the value range of historical explosion risk values, and form a risk rating standard based on the value range of historical explosion risk values.

[0006] Preferably, the steps for identifying the wall thickness of the gas transmission pipeline to obtain at least one vulnerable position and the parameters of the vulnerable position are as follows: Based on the historical explosion data of the gas power plant, obtain at least one historical event of the explosion of the gas transmission pipeline; Obtain the maximum wall thickness of the explosion of the gas transmission pipeline in the historical event as the thickness critical value; Take the positions in the gas transmission pipeline where the wall thickness does not exceed the thickness critical value as the vulnerable positions respectively; Obtain the central coordinates at the center of the vulnerable position, uniformly set at least one sampling point at the vulnerable position, and the distance between adjacent sampling points is equal to the preset distance, and the preset distance is the distance that meets the sampling accuracy; Obtain the wall thickness at the sampling point, summarize at least one sampling point at the vulnerable position as a sampling point set, and take the central coordinates of the vulnerable position and the sampling point set as the parameters of the vulnerable position.

[0007] Preferably, the steps for calculating the gas leakage possibility and the gas leakage speed according to the parameters of the vulnerable position are as follows: Obtain the occurrence time interval of at least one historical event of the explosion of the gas transmission pipeline, and the occurrence time interval is composed of the minimum value and the maximum value of the occurrence time points of the historical events; Obtain the average value of the wall thickness at the explosion point of the exploded gas transmission pipeline in the historical event as the explosion characteristic value; Take the duration of the historical event as the target time, and divide the target time by the length of the occurrence time interval to obtain the occurrence probability; Pair the explosion characteristic value of the historical event with the occurrence probability, and match the occurrence probability corresponding to the explosion characteristic value equal to the wall thickness of the sampling point to the sampling point; Take the average value of the occurrence probabilities of the sampling points in the sampling point set of the vulnerable position to obtain the gas leakage possibility; Obtain the transmission speed of the gas transmission pipeline, obtain the cross-sectional area of the gas transmission pipeline, and obtain the area of the coverage range of the sampling points at the vulnerable position as the characteristic area; Divide the characteristic area by the number of sampling points in the sampling point set of the vulnerable position to obtain the average area; Multiply and accumulate the occurrence probabilities of the sampling points in the sampling point set by the average area to obtain the target area; Divide the target area by the characteristic area to obtain the regulation coefficient, and multiply the regulation coefficient by the transmission speed of the gas transmission pipeline to obtain the gas leakage speed.

[0008] Preferably, the steps for merging the vulnerable positions to obtain at least one set of vulnerable positions are as follows: Based on historical data, obtain the maximum distance of the gas stack as the characteristic distance. Associate and set two of the vulnerable positions with a distance less than the characteristic distance, and summarize the associated vulnerable positions to obtain a set of vulnerable positions.

[0009] Preferably, the formation of the explosion hazard area based on the set of vulnerable positions includes the following steps: Regard the area with a distance less than the characteristic distance from the vulnerable position as the characteristic area. Take the intersection of the characteristic area and the gas power plant to obtain the target area. Merge the target areas of the vulnerable positions in the set of vulnerable positions to obtain the explosion hazard area.

[0010] Preferably, the analysis of the spatial structure and ventilation condition of the explosion hazard area to obtain the gas accumulation rate includes the following steps: Evenly divide the explosion hazard area to obtain at least one sampling space, and calculate the ratio of the blocked area on the surface of the sampling space to the surface area of the sampling space to obtain the blocking coefficient. Based on historical data, obtain the average air diffusion rate in the gas power plant. Multiply the blocking coefficient of the sampling space by the average air diffusion rate to obtain the actual diffusion rate of the sampling space. Take the average value of the actual diffusion rates of the sampling spaces in the explosion hazard area to obtain the average diffusion rate of the explosion hazard area. Multiply the preset time by the average diffusion rate to obtain the air replenishment space. Add the air replenishment space to the total volume of the explosion hazard area to obtain the effective space volume. Calculate the ratio of the total volume of the explosion hazard area to the effective space volume to obtain the effective coefficient. The preset time is the time set based on the evaluation accuracy. Multiply and superimpose the gas leakage rates of the vulnerable positions in the set of vulnerable positions corresponding to the explosion hazard area by the effective coefficient to obtain the gas accumulation rate.

[0011] Preferably, the analysis of the possibility of the existence of a fire source in the explosion hazard area to obtain the fire source appearance coefficient includes the following steps: Based on historical data, obtain the historical fire sources that have appeared in the explosion hazard area, and obtain the combustion scale and existence probability of the historical fire sources. The existence probability is the ratio of the appearance time length of the historical fire sources in one year to one year. Multiply the combustion scale and the existence probability of the historical fire source to obtain the fire source appearance coefficient.

[0012] Preferably, the obtaining of the critical conditions for gas detonation based on historical data includes the following steps: Based on historical data, obtain the lowest concentration of gas detonation as the critical condition for gas detonation.

[0013] Preferably, the calculation of the explosion risk value for the explosion - hazardous area includes the following steps: Obtain the maintenance time interval of the gas - fired power plant, multiply the maintenance time interval by the gas accumulation rate to obtain the gas accumulation value; Divide the gas accumulation value by the total volume of the explosion - hazardous area to obtain the gas accumulation concentration; When the gas accumulation concentration is less than the minimum concentration for gas detonation, the explosion risk value of the explosion - hazardous area is 0; otherwise, the explosion risk value of the explosion - hazardous area is equal to the product of the gas accumulation concentration, the leakage probability, and the fire - source appearance coefficient; The specific method for obtaining the leakage probability is as follows: Obtain the, use the reverse - probability formula to calculate the leakage probability of the explosion - hazardous area; The reverse - probability formula is as follows: , where A is the leakage probability of the explosion - hazardous area, i is the subscript, is the gas leakage possibility of the i - th vulnerable location in the set of vulnerable locations corresponding to the explosion - hazardous area, and n is the number of elements in the set of vulnerable locations corresponding to the explosion - hazardous area.

[0014] Preferably, the formation of the risk - rating standard based on the value range of the historical explosion risk value includes the following steps: Evenly divide the value range of the historical explosion risk value to obtain at least one risk range; Number the risk ranges according to the central values of the risk ranges, and use the numbers of the risk ranges as the risk levels of the risk ranges; When the explosion risk value belongs to a risk range, assign the risk level of the risk range to the explosion risk value.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By performing merging processing on vulnerable locations, calculating gas leakage possibility and gas leakage rate, analyzing and calculating the spatial structure and ventilation conditions of the explosion - hazardous area to obtain the explosion risk value of the explosion - hazardous area, it is possible to estimate the air - flow situation according to the environmental characteristics in the gas - fired power plant, and combine the gas leakage possibility and gas leakage rate of vulnerable locations, so as to estimate the overall gas accumulation situation, thereby being able to more accurately depict the explosion risk, and the obtained evaluation results have a high degree of coincidence with the actual situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic flow chart of the method for risk assessment of the explosion - hazardous area of a gas - fired power plant based on environmental characteristics according to the present invention; Figure 2Schematic flow chart for identifying the wall thickness of a gas transmission pipeline in the present invention to obtain at least one vulnerable location and the parameters of the vulnerable location; Figure 3 Schematic flow chart for calculating the gas leakage probability and gas leakage rate according to the parameters of the vulnerable location in the present invention; Figure 4 Schematic flow chart for merging and processing the vulnerable locations to obtain at least one set of vulnerable locations in the present invention; Figure 5 Schematic flow chart for forming an explosion hazard area based on the set of vulnerable locations in the present invention; Figure 6 Schematic flow chart for analyzing the spatial structure and ventilation conditions of the explosion hazard area to obtain the gas accumulation rate in the present invention; Figure 7 Schematic flow chart for analyzing the possibility of the presence of a fire source in the explosion hazard area to obtain the fire source appearance coefficient in the present invention; Figure 8 Schematic flow chart for calculating the explosion risk value of the explosion hazard area in the present invention; Figure 9 Schematic flow chart for forming a risk rating standard based on the value range of the historical explosion risk value in the present invention. Detailed implementation manners

[0017] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations.

[0018] Refer to Figure 1 As shown, the method for risk assessment of explosion hazard areas in gas power plants based on environmental characteristics includes: Obtain at least one gas transmission pipeline of the gas power generation equipment in the gas power plant, identify the wall thickness of the gas transmission pipeline to obtain at least one vulnerable location and the parameters of the vulnerable location, and obtain the position coordinates of the vulnerable location; Calculate the gas leakage probability and gas leakage rate according to the parameters of the vulnerable location; Based on the position attributes of the vulnerable locations, merge and process the vulnerable locations to obtain at least one set of vulnerable locations; Form an explosion hazard area based on the set of vulnerable locations, analyze the spatial structure and ventilation conditions of the explosion hazard area to obtain the gas accumulation rate; Analyze the possibility of the presence of a fire source in the explosion hazard area to obtain the fire source appearance coefficient; Based on historical data, obtain the critical conditions for gas detonation. Calculate the explosion risk value of the explosion hazard area based on the critical conditions for gas detonation, the occurrence coefficient of the ignition source, the gas accumulation rate, the gas leakage possibility, and the gas leakage speed. Based on historical data, obtain the value range of historical explosion risk values, and form a risk rating standard based on the value range of historical explosion risk values.

[0019] When conducting explosion assessment, there are multiple vulnerable positions in the gas transmission pipeline. The situation of each vulnerable position is different, and the leakage possibility is different. Also, due to the difference in the pipe diameter of the gas transmission pipeline, the transmission speed is different. Therefore, during leakage, it is also necessary to distinguish and process. Moreover, the spatial distribution of vulnerable positions is different, and the leakage situations of some vulnerable positions need to be combined for processing. Because when the distance between vulnerable positions is very close, the leaked gas will have a superimposed effect. The concentration of a single leak may be too low to cause an explosion, but the superimposed effect of multiple adjacent vulnerable positions may result in an explosion possibility. Therefore, for this situation, corresponding algorithms need to be set up for processing.

[0020] Refer to Figure 2 As shown in Based on the historical explosion data of the gas power plant, obtain at least one historical event of gas transmission pipeline explosion. Obtain the maximum wall thickness of the gas transmission pipeline explosion in the historical event as the thickness critical value. Take the positions in the gas transmission pipeline where the wall thickness does not exceed the thickness critical value as vulnerable positions respectively. Obtain the central coordinates at the center of the vulnerable position, and evenly set at least one sampling point at the vulnerable position. The distance between adjacent sampling points is equal to the preset distance, and the preset distance is the distance that meets the sampling accuracy. Obtain the wall thickness at the sampling point, and summarize at least one sampling point at the vulnerable position as a sampling point set. Take the central coordinates of the vulnerable position and the sampling point set as the parameters of the vulnerable position.

[0021] There is a great correlation between the wall thickness of the pipe wall and the possibility of leakage at the vulnerable position. When the wall thickness is smaller, the possibility of crack leakage is greater, and vice versa.

[0022] Refer to Figure 3 As shown in Obtain the occurrence time interval of at least one historical event of gas transmission pipeline explosion. The occurrence time interval is composed of the minimum value and the maximum value of the occurrence time points of the historical events. Obtain the average value of the wall thickness at the explosion point of the gas transmission pipeline that exploded in the historical event as the explosion characteristic value; Take the duration of the historical event as the target time, and divide the target time by the length of the occurrence time interval to obtain the occurrence probability; Pair the explosion characteristic value of the historical event with the occurrence probability, and match the occurrence probability corresponding to the explosion characteristic value equal to the wall thickness of the sampling point to the sampling point; Take the average value of the occurrence probabilities of the sampling points in the sampling point set at the vulnerable location to obtain the gas leakage possibility; Obtain the transmission speed of the gas transmission pipeline, obtain the cross-sectional area of the gas transmission pipeline, and obtain the area of the coverage range of the sampling points at the vulnerable location as the characteristic area; Divide the characteristic area by the number of sampling points in the sampling point set at the vulnerable location to obtain the average area; Multiply and accumulate the occurrence probabilities of the sampling points in the sampling point set by the average area to obtain the target area; Divide the target area by the characteristic area to obtain the regulation coefficient, and multiply the regulation coefficient by the transmission speed of the gas transmission pipeline to obtain the gas leakage speed.

[0023] The leakage situation at the vulnerable location is mainly related to the thickness of the pipeline at the vulnerable location. Considering that the pipeline thickness in the vulnerable location may be inconsistent, therefore, sampling and discrimination processing is carried out, and the situation of the sampling points is comprehensively considered, so that the situation of the vulnerable location can be estimated more accurately. And according to the accuracy requirements of the estimation, the number of sampling points can be increased. And the leakage situation is related to the leakage area. Since the leakage area is related to the leakage possibility, therefore, it needs to be multiplied by the occurrence probability to obtain the target area, and the target area is used to describe the leakage area. Since the speed at each point is the same during transmission, therefore, the total leakage speed is proportional to the size of the target area. Thus, the gas leakage speed can be calculated accordingly.

[0024] Refer to Figure 4 As shown, the steps for merging the vulnerable locations to obtain at least one vulnerable location set are as follows: Based on historical data, obtain the maximum distance of gas stacking as the characteristic distance; Set the two vulnerable locations with a distance less than the characteristic distance to be associated, and summarize the associated vulnerable locations to obtain the vulnerable location set.

[0025] Some of the vulnerable locations are relatively close, and there is an effect of gas concentration superposition. Therefore, when considering, these places need to be comprehensively considered. Considering them individually will lead to omissions in identification; The maximum distance of the gas stack is mainly measured by superimposing the concentrations at two vulnerable positions. When there is a place in the space between them where the concentration is higher than that at both vulnerable positions, it indicates that the distance between them is relatively close, and there is an overlapping effect of the two at the position between them. Therefore, the two vulnerable positions need to be considered in combination, and based on the combination of the two vulnerable positions, all vulnerable positions are combined and processed.

[0026] Refer to Figure 5 As shown, forming an explosion hazard area based on the set of vulnerable positions includes the following steps: Regard the area where the distance to the vulnerable position is less than the characteristic distance as the characteristic area; Take the intersection of the characteristic area and the gas power plant to obtain the target area; Merge the target areas of the vulnerable positions in the set of vulnerable positions to obtain the explosion hazard area.

[0027] Refer to Figure 6 As shown, analyzing the spatial structure and ventilation conditions of the explosion hazard area to obtain the gas accumulation rate includes the following steps: Evenly divide the explosion hazard area to obtain at least one sampling space, and calculate the ratio of the blocked area on the surface of the sampling space to the surface area of the sampling space to obtain the blocking coefficient; Based on historical data, obtain the average air diffusion rate in the gas power plant; Multiply the blocking coefficient of the sampling space by the average air diffusion rate to obtain the actual diffusion rate of the sampling space, and take the average value of the actual diffusion rates of the sampling spaces in the explosion hazard area to obtain the average diffusion rate of the explosion hazard area; Multiply the preset time by the average diffusion rate to obtain the air replenishment space, add the air replenishment space to the total volume of the explosion hazard area to obtain the effective space volume, and calculate the ratio of the total volume of the explosion hazard area to the effective space volume to obtain the effective coefficient. The preset time is the time set based on the evaluation accuracy; Multiply and superimpose the gas leakage rates of the vulnerable positions in the set of vulnerable positions corresponding to the explosion hazard area by the effective coefficient to obtain the gas accumulation rate.

[0028] The preset time is an extremely small time. The smaller it is, the higher the calculation accuracy of the gas accumulation rate, because the speed is almost constant throughout the preset time, so the same speed can be used for calculation. Therefore, there will be no too large error, and according to the requirement for accuracy, the preset time can be further reduced; Due to the different spatial structures and ventilation conditions in the explosion - hazardous area, when air circulates therein, the circulation speed may decrease due to obstruction. As a result, the gas concentrations accumulated in the explosion - hazardous area are different. And explosion mainly depends on the ignition source and gas concentration. The gas concentration must be the one accumulated in the explosion - hazardous area, rather than the concentration calculated based on leakage. Therefore, the diffusion average speed depicts the replenishment speed of the air in the explosion - hazardous area. Thus, the volume of air replenished into the explosion - hazardous area within a preset time can be obtained, and then based on this, the actual gas concentration can be calculated. Here, it also relies on the law that the gas will be evenly distributed in the air replenished into the explosion - hazardous area and the air in the explosion - hazardous area itself.

[0029] Refer to Figure 7 As shown, to analyze the possibility of the ignition source in the explosion - hazardous area, the steps to obtain the ignition - source appearance coefficient are as follows: Based on historical data, obtain the historical ignition sources that appeared in the explosion - hazardous area, and obtain the combustion scale and existence probability of the historical ignition sources. The existence probability is the ratio of the appearance time length of the historical ignition sources within one year to one year. Multiply the combustion scale and the existence probability of the historical ignition sources to obtain the ignition - source appearance coefficient.

[0030] Based on historical data, the steps to obtain the critical condition for gas detonation are as follows: Based on historical data, obtain the lowest concentration for gas detonation as the critical condition for gas detonation.

[0031] Refer to Figure 8 As shown, the steps to calculate the explosion risk value of the explosion - hazardous area are as follows: Obtain the maintenance time interval of the gas power plant, and multiply the maintenance time interval by the gas accumulation speed to obtain the gas accumulation value. Divide the gas accumulation value by the total volume of the explosion - hazardous area to obtain the gas accumulation concentration. When the gas accumulation concentration is less than the lowest concentration for gas detonation, the explosion risk value of the explosion - hazardous area is 0; otherwise, the explosion risk value of the explosion - hazardous area is equal to the product of the gas accumulation concentration, the leakage probability, and the ignition - source appearance coefficient. The specific method to obtain the leakage probability is as follows: Obtain the [relevant information of] the explosion - hazardous area, and use the reverse - probability formula to calculate the leakage probability of the explosion - hazardous area. The reverse - probability formula is as follows: , where A is the leakage probability of the explosion - hazardous area, and i is the subscript. $P_i$ is the probability of gas leakage at the $i$-th vulnerable location in the set of vulnerable locations corresponding to the explosion hazard area, and $n$ is the number of elements in the set of vulnerable locations corresponding to the explosion hazard area.

[0032] During maintenance, the concentration will be detected, and thus repairs will be carried out according to the detection results. When the interval between maintenance does not pose an explosion possibility, all potential hazards will be eliminated during maintenance. Therefore, when the cumulative gas concentration is less than the minimum concentration for gas detonation, the explosion risk value of the explosion hazard area is 0. Since the explosion hazard area is formed by a set of vulnerable locations, whether it explodes only requires leakage from one of the vulnerable locations, and it is not necessary for all vulnerable locations to leak. Therefore, when calculating the leakage probability, it calculates the probability of leakage from one of the vulnerable locations in the set of vulnerable locations.

[0033] Refer to Figure 9 As shown, based on the value range of the historical explosion risk value, forming a risk rating standard includes the following steps: Evenly divide the value range of the historical explosion risk value to obtain at least one risk range; Number the risk ranges according to the central values of the risk ranges, and use the numbers of the risk ranges as the risk levels of the risk ranges; When the explosion risk value belongs to a risk range, assign the risk level of the risk range to the explosion risk value.

[0034] Furthermore, this solution also proposes a storage medium on which a computer-readable program is stored. When the computer-readable program is called, it executes the above-mentioned risk assessment method for the explosion hazard area of a gas power plant based on environmental characteristics.

[0035] It can be understood that the storage medium can be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; an optical medium, such as a DVD; or a semiconductor medium, such as a solid-state drive (SSD).

[0036] In summary, the advantages of the present invention are as follows: By performing merging processing on vulnerable locations, calculating the probability of gas leakage and the gas leakage speed, analyzing and calculating the spatial structure and ventilation conditions of the explosion hazard area to obtain the explosion risk value of the explosion hazard area, it can estimate the air flow situation based on the environmental characteristics in the gas power plant, and combine the probability of gas leakage and the gas leakage speed of the vulnerable locations, thereby estimating the overall gas accumulation situation, and thus can more accurately depict the explosion risk, and the obtained evaluation results have a high degree of coincidence with the actual situation.

[0037] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, various changes and improvements will occur to the present invention, and all these changes and improvements fall within the scope of the present invention claimed. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. A risk assessment method for explosion hazard areas in gas power plants based on environmental characteristics, characterized in that: include: Acquire at least one gas transmission pipeline of a gas power generation device of a gas power plant, identify the wall thickness of the gas transmission pipeline, obtain at least one vulnerable position and parameters of the vulnerable position, and obtain the position coordinates of the vulnerable position; Calculate the possibility and speed of gas leakage based on the parameters of vulnerable locations; Based on the location attributes of the vulnerable locations, the vulnerable locations are merged to obtain at least one vulnerable location set; The explosion hazard zone is formed based on the set of vulnerable locations, and the spatial structure and ventilation conditions of the explosion hazard zone are analyzed to obtain the gas accumulation velocity; Analyze the possibility of fire sources in explosion-hazardous areas and obtain the fire source occurrence coefficient; Based on historical data, the critical conditions for gas explosion are obtained, and based on the critical conditions for gas explosion, the fire source occurrence coefficient, the gas accumulation rate, the possibility of gas leakage and the gas leakage rate, the explosion risk value of the explosion-hazardous area is calculated; Based on historical data, the value range of historical explosion risk values ​​is obtained, and based on the value range of historical explosion risk values, a risk rating standard is formed.

2. The method for risk assessment of explosion hazard areas in gas power plants based on environmental characteristics according to claim 1 is characterized in that: The method of identifying the wall thickness of the gas transmission pipeline to obtain at least one vulnerable position and parameters of the vulnerable position comprises the following steps: Based on historical explosion data of the gas power plant, obtaining at least one historical event of gas transmission pipeline explosion; Obtain the maximum value of the pipe wall thickness of the gas transmission pipeline explosion in historical events as the thickness critical value; The positions where the pipe wall thickness in the gas transmission pipeline does not exceed the critical thickness value are respectively regarded as vulnerable positions; Obtain the center coordinates of the center of the vulnerable position, evenly set at least one sampling point at the vulnerable position, and the distance between adjacent sampling points is equal to a preset distance, which is a distance that meets the sampling accuracy; The pipe wall thickness at the sampling point is obtained, at least one sampling point at the vulnerable position is aggregated into a sampling point set, and the center coordinates of the vulnerable position and the sampling point set are used as parameters of the vulnerable position.

3. The method for risk assessment of explosion hazard areas in gas power plants based on environmental characteristics according to claim 2 is characterized in that: Calculating the possibility of gas leakage and the gas leakage rate according to the parameters of the vulnerable position includes the following steps: Obtaining a time interval of occurrence of at least one historical event of gas transmission pipeline explosion, where the time interval is composed of a minimum value and a maximum value of the time points of occurrence of the historical event; Obtaining an average value of the pipe wall thickness at the explosion point of the gas transmission pipeline that exploded in the historical event as an explosion characteristic value; The duration of the historical event is taken as the target time, and the target time is compared with the length of the occurrence time interval to obtain the probability of occurrence; Pair the explosion characteristic values ​​of historical events with the probability of occurrence, and match the probability of occurrence corresponding to the explosion characteristic value equal to the pipe wall thickness at the sampling point to the sampling point; The probability of occurrence of the sampling points in the set of sampling points at the vulnerable position is averaged to obtain the possibility of gas leakage; Obtaining the transmission speed of the gas transmission pipeline, obtaining the pipeline cross-sectional area of ​​the gas transmission pipeline, and obtaining the coverage area of ​​the sampling points at the vulnerable position as the characteristic area; The characteristic area is divided by the number of sampling points in the set of sampling points at the vulnerable position to obtain the mean area; The occurrence probability of the sampling points in the sampling point set is multiplied by the mean area and then accumulated to obtain the target area; The target area is divided by the characteristic area to obtain the control coefficient, and the control coefficient is multiplied by the transmission speed of the gas transmission pipeline to obtain the gas leakage rate.

4. The method for risk assessment of explosion hazard areas in gas power plants based on environmental characteristics according to claim 3 is characterized in that: The merging of vulnerable positions to obtain at least one vulnerable position set comprises the following steps: Based on historical data, the maximum distance of gas stacking is obtained as the characteristic distance; The two vulnerable positions whose distance is less than the characteristic distance are associated with each other, and the associated vulnerable positions are aggregated to obtain a vulnerable position set.

5. The method for risk assessment of explosion hazard areas in gas power plants based on environmental characteristics according to claim 4 is characterized in that: The forming of the explosion hazard zone based on the vulnerable location set comprises the following steps: The area whose distance to the vulnerable position is less than the characteristic distance is regarded as the characteristic area; Intersect the characteristic area with the gas power plant to obtain the target area; The target areas of vulnerable locations in the vulnerable location set are merged to obtain the explosion hazard area.

6. The method for risk assessment of explosion hazard areas in gas power plants based on environmental characteristics according to claim 5 is characterized in that: The analysis of the spatial structure and ventilation conditions of the explosion-hazardous area to obtain the gas accumulation rate includes the following steps: Uniformly divide the explosion hazard zone to obtain at least one sampling space, compare the blocked area of ​​the sampling space surface with the surface area of ​​the sampling space to obtain a barrier coefficient; Based on historical data, obtain the average air diffusion velocity in the gas power plant; The barrier coefficient of the sampling space is multiplied by the average diffusion velocity of the air to obtain the actual diffusion velocity of the sampling space. The actual diffusion velocity of the sampling space in the explosion hazard area is averaged to obtain the average diffusion velocity of the explosion hazard area. The preset time is multiplied by the average diffusion speed to obtain the air replenishment space. The air replenishment space is added to the total volume of the explosion hazardous area to obtain the effective space volume. The total volume of the explosion hazardous area is compared with the effective space volume to obtain the effective coefficient. The preset time is the time set based on the evaluation accuracy. The gas leakage rate at the vulnerable position in the vulnerable position set corresponding to the explosion hazardous area is multiplied by the effectiveness coefficient and superimposed to obtain the gas cumulative rate.

7. The method for risk assessment of explosion hazard areas in gas power plants based on environmental characteristics according to claim 6 is characterized in that: The analysis of the possibility of fire source in the explosion hazard area to obtain the fire source occurrence coefficient includes the following steps: Based on historical data, obtain the historical fire sources that appeared in the explosion hazard area, and obtain the combustion scale and existence probability of the historical fire sources. The existence probability is the ratio of the length of time the historical fire sources appeared within a year to one year; The combustion scale and existence probability of historical fire sources are multiplied to obtain the fire source occurrence coefficient.

8. The method for risk assessment of explosion hazard areas in gas power plants based on environmental characteristics according to claim 7 is characterized in that: The method of obtaining the critical conditions for gas detonation based on historical data includes the following steps: Based on historical data, the minimum concentration of gas explosion is obtained as the critical condition for gas explosion.

9. The method for risk assessment of explosion hazard areas in gas power plants based on environmental characteristics according to claim 8, characterized in that: The calculation to obtain the explosion risk value of the explosion hazardous area comprises the following steps: Obtain the maintenance time interval of the gas power plant, multiply the maintenance time interval by the gas accumulation rate to obtain the gas accumulation value; The gas accumulation value is compared with the total volume of the explosion-hazardous area to obtain the gas accumulation concentration; When the cumulative concentration of gas is less than the minimum concentration for gas detonation, the explosion risk value of the explosion-hazardous area is 0. Otherwise, the explosion risk value of the explosion-hazardous area is equal to the product of the cumulative concentration of gas, the probability of leakage and the coefficient of fire source occurrence. The leakage probability is obtained as follows: If explosion hazardous areas are obtained, the inverse probability formula is used to calculate the leakage probability of explosion hazardous areas; The inverse probability formula is as follows: , Among them, A is the leakage probability of the explosion hazard area, i is the subscript, is the gas leakage possibility of the ith vulnerable location in the vulnerable location set corresponding to the explosion hazardous area, and n is the number of elements in the vulnerable location set corresponding to the explosion hazardous area.

10. The method for risk assessment of explosion hazard areas in gas power plants based on environmental characteristics according to claim 9, characterized in that: The risk rating standard formed based on the value range of the historical explosion risk value includes the following steps: Evenly divide the value range of historical explosion risk values ​​to obtain at least one risk range; The risk ranges are numbered according to the central value of the risk range, and the number of the risk range is used as the risk level of the risk range; When the explosion risk value belongs to the risk range, the risk level of the risk range is assigned to the explosion risk value.

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