JPH0843239A - Method for estimating area and amount of gas leakage taking obstacle into consideration - Google Patents

Abstract

PURPOSE:To estimate the area of gas leakage from gas concentration data and anemometer data by estimating the standard deviation of the gas concentration distribution of a gaseous diffusion equation from the standard deviation of the wind direction variation of an anemovane at every bearing. CONSTITUTION:A data processor 3 calculates gas flux by taking out gas concentration data from a gas concentration data collecting/storing device 1 and wind direction and speed data for each detector from a wind direction and speed collecting/storing device 2 and multiplying the former data by the latter data. For example, gas detectors G1-G10 are arranged around a frame at regular intervals of 20m in a state where the detectors G1-G10 are respectively united with anemovanes B1-B10 and the mean values and standard deviation of the wind directions and speeds corresponding to the detectors G1-G10 are found based on the data from the anemovanes B1-B10. At the time of finding the mean value and standard deviation, established correction is performed so that sigmaY=0.018XsigmaA and sigmaZ=0.054KXsigmaE (where, sigmaY and sigmaZ respectively represent the standard deviations of gas concentration distributions in Y- and Z- directions, sigmaA and sigmaE respectively represent the standard deviations of wind direction variation in the horizontal and vertical directions, and K represents an empirical constant which varies depending upon the stability of atmosphere) can hold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention corresponds to a gas leakage region in a gas leakage and a diffusion state of the atmosphere in a region targeted for the amount of gas leakage, and automatically influences an obstacle to the flow of the atmosphere. The method of evaluation and estimation is based on data such as the standard deviation of the wind direction fluctuation of the atmosphere in the target area, the wind direction wind speed, and the gas concentration, and is mainly used for gases such as combustible gas, toxic gas, various oils, and vapors of organic solvents. The present invention relates to a gas leakage region and a method for estimating a gas leakage amount, which are useful for early countermeasures against gas leakage in various field plants that may leak.

[0002]

2. Description of the Related Art Conventionally, there has been a problem that it is not possible to observe a local turbulent diffusion state of the atmosphere in a target area and estimate a gas leakage region based on the data.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior art as described above, and the main purpose of the present invention is to observe the local turbulent diffusion state of the atmosphere,
It is to provide a method for estimating a gas leakage region and a gas leakage amount based on the data.

[0004]

According to the present invention, the above-mentioned objects are installed in the vicinity of the gas concentration data from the gas detector based on the three-dimensional gas diffusion formula in the atmospheric diffusion. A method for estimating the gas leakage region from the wind direction and wind speed data from the wind direction and anemometer, wherein the standard deviation of the gas concentration distribution in the gas diffusion formula is the standard deviation of the wind direction fluctuation from the wind direction and anemometer for each direction. It is achieved by providing a method for estimating a gas leakage amount, which is characterized by estimating a gas leakage region from the gas concentration data and the wind direction wind speed data.

[0005]

The diffusion of the leaked gas is based on the normal type three-dimensional gas diffusion equation given by the following equation. Of course, the same applies if a diffusion formula other than the normal type such as the Sakagami formula is used.

[0006]

[Equation 1]

[0007]

[Equation 2]

[0008]

(Equation 3)

G in the equation (2) is an equation when there is no horizontal obstacle such as a pedestal that prevents vertical diffusion in the upper space from the gas leak point to the gas detector, and G in the equation (3) is the upper portion. This is the case when there are horizontal obstacles such as a gantry that prevent vertical diffusion in the space.

The symbols included in the equations (1) to (3) will be described below in consideration of the plant. C: Arbitrary position coordinates (x, y, z) when the coordinate of the gas leak point is (0, 0, H) and the x axis is taken in the direction of the wind when the leaked gas leaks at a concentration of 100% Concentration of gas (m ³ / m ³ ). Q: amount of leaked gas per unit time (m ³ / s) at gas leak point (0, 0, H) U: wind speed (m / s) H: The height of the leak point from the ground surface. If there is a floor such as a pedestal, set the height above the floor (m). z is also an arbitrary height from the same floor (m). T: The distance (m) between upper and lower horizontal obstacles (including the ground) when there is a horizontal obstacle such as a gantry that prevents vertical diffusion in the upper space from the gas leak point to the gas detector. m: the number of reflections, which is usually a good approximation if m = -2 to 2 is taken. σy, σz: standard deviation (m) of the gas concentration distribution in the y and z directions.

Now, as shown in FIG. 1, the r-th wind direction αr
(Radian), i-th gas detector G for wind speed Ur
leakage gas concentration Ci, r for i (Xi, Yi, Xi),
That is, it is assumed that the value Fi, r = Ci, r × Ur of the gas flux and the direction αr of the direction of the gas flux are obtained. Since these data have fluctuations inherently, for example, the logarithm of the values of three or more gas fluxes with respect to the i-th gas detector can be approximated by an upwardly convex quadratic equation regarding the direction of the direction of the regression analysis. Then, the values of the gas flux for the two directions may be selected. In this case, a function other than the quadratic equation may be used for approximation. These two directions are again αr
And αs, and the gas flux values are Fi, r and Fi, s.

It is also assumed that the gas leakage point P (X, Y, H) is on the horizontal plane of the height Z of the gas detector Gi or its vicinity, and this point is defined as P '(X, Y, H). Z). Gi ′ (Xi, Yi, Z) in FIG. 1 is a point obtained by projecting the Gi point on a horizontal plane of height Z. As for the position of the gas detector Gi, x is Li, r, y is Wi, r, and z is Z in the equation (1) for an arbitrary wind direction.
It is obtained by setting i. Therefore, the above formula (1)
When is transformed into a form solved for Q, the following equation is obtained.

[0013]

[Equation 4]

Yamamoto et al. Obtained the following equation as an empirical equation for σy and σz. σy = 0.018xσ _A (5) σz = 0.0054 κxσ _E (6) where σ _A and σ _E are standard deviations (degrees) of horizontal and vertical wind direction fluctuations, and κ is an experiment depending on atmospheric stability. It is a constant.

Σ _A has a correlation with atmospheric stability, and Pasquill-
Σ _y of each stability class at 100 m in the Gifford diagram
Compared with, σ _A is related as shown in Table 1.
As shown in the lower part of Table 1, κ can be estimated from σ _A. κ
Since is a discrete value, it may be correlated as a smooth curve. In this case, the numerical value does not change so much even if the position is 50 m instead of 100 m. This distance may be an average value between the gas detector and the gas leak point.

[0016]

[Table 1]

Therefore, it is only necessary to measure σ _A and σ _E. However, when σ _E is not measured, the correlation between σ _A and σ _E depends on local characteristics such as pedestals and equipment in the plant. Therefore, the correlation between σ _A and σ _E may be measured in advance and a correlation equation showing these influences may be created. Further, looking at some data in the case where there is no obstacle already measured, σ _E is about half of σ _A , so σ _E = σ _A / 2 may be used as the first approximation. As can be seen from the fact that σ _A correlates with atmospheric stability, it is also affected by the secondary and tertiary turbulence generated by various obstacles in the plant. By measuring _A and using the data, it can be evaluated directly.

Particularly, using the standard deviation of the gas concentration distribution estimated based on the standard deviation of the direction of the gas flux direction used in the regression analysis, the value of the gas flux used in the calculation and the direction of the direction It is desirable because it is consistent with

If σ _A at the gas detection point is used, the value will include the atmospheric stability and the influence of various obstacles in each direction in the plant. Therefore, a gas detector integrated with an anemometer Therefore, it is desirable to measure the gas concentration and the wind direction. If it is not a gas detector integrated with an anemometer, from an anemometer near the gas detector in a place with few obstacles around it or from an anemometer in a place with few obstacles on the windward side. It is recommended to estimate as follows using the wind direction and wind speed data.

The azimuth of each gas detector is divided into 8 equal parts or 16 equal parts, for example, and the left and right angle of view (degrees) corresponding to the width of the obstacle is given in advance for each azimuth, and the wind direction wind speed data is obtained. If the numerical value obtained by dividing the angle of view by the standard deviation of horizontal wind direction fluctuation is 1 or more, the standard deviation of horizontal wind direction fluctuation,
It is advisable to estimate the standard deviation of the gas concentration distribution in the Y direction by using the standard deviation limited to a predetermined value times, for example, 10 times, instead of the standard deviation of the horizontal wind direction fluctuation. The angle of view can be obtained as an interior angle (degree) of a line connecting an obstacle, for example, both sides of the distillation column and the gas detector at each angular direction of the gas detector.

Similarly, the vertical angle of view (degree) obtained in advance as the interior angle (degree) of the line connecting the upper and lower side surfaces of an obstacle such as a horizontal heat exchanger to the gas detector is given in advance. If the value obtained by dividing the angle of view by the standard deviation of fluctuation is 1 or more, the standard deviation of the standard deviation of the vertical wind direction fluctuation is limited to a predetermined value times, for example, 10 times the standard deviation of the vertical wind direction fluctuation. Instead, it may be used to estimate the standard deviation of the gas concentration distribution in the z direction.

Substituting X in equations (5) and (6) for Li, r into equation (4) yields a virtual gas leakage amount Qi, r. For the i-th gas detector Gi, Qi, r and Qi, s corresponding to the r-th and s-th gas flux data are set at arbitrary points (X, Y, Z) on the horizontal plane of height Z. Then, the locus of points at which Qi, r = Qi, s or ln (Qi, r / Qi, s) = 0 (7) can be obtained by trial calculation.

This locus yields similar curves for any two data for the ith gas detector Gi and these curves do not intersect. Next, the jth gas detector Gj
A similar trajectory is obtained for the i-th gas detector G
The estimated gas leakage point P '(X, Y, Z) is the point intersecting the trajectory obtained in i. At this intersection Qi = Qj
If this is the case, the gas leak point P (X, Y, H) is correct, but if not, the three-dimensional position where Qi = Qj is recalculated and recalculated first is the gas leak point P (X, Y, H).
Y, H) is given, and the amount of gas leakage obtained by Q at this time is given.

With respect to the empirical formula of Yamamoto et al., An analytical approximate solution expressed in polar coordinates as in the following formula can be obtained.

[0025]

(Equation 5)

Here, Ri and βi (radian) are the distance (radius) and direction from the position of the gas detector Gi to the gas detector P ′. The formula (8) is a formula derived on the assumption that the gas is not reflected by the upper and lower obstacles.

In the above equation, when Z = Zi or Ri is about 30 m or more, the second and third terms in {} of the above equation can be ignored. If (αr-αs) is set equal to the standard deviation of the horizontal wind direction fluctuation, the above equation can be simplified as the following equation.

[0028]

(Equation 6)

In the above equation, σ _AO indicates that σ _A is expressed in radian unit, and ± means that the first term of the above equation is ln (Fi, r / Fi,
s) / (αr−αs). From the formula (9), the influence of the obstacle is basically ln (Fi, r / Fi,
It can be expressed as the product of s) and σ _A.

From the gas leakage point P'obtained based on the equation (8), Qi = Qj is obtained by the same method as described above (X,
The three-dimensional position of (Y, H) and the gas leakage amount Q at this time can be obtained.

The present method is used for estimating the gas leakage region from the average gas concentration data from the gas detector having a plurality of gas detection points and the wind direction and wind speed data from the wind anemometer near the gas detector. Can also be applied. Further, for example, the standard deviation of the wind direction fluctuation is obtained based on the wind direction data from the wind direction anemometer on the roof of the instrument room in the factory, and the standard deviation of the gas concentration distribution in the gas diffusion formula is estimated from this, and only the gas concentration data, or The gas leakage area can be estimated from the gas concentration data and the wind speed data.

In any case, the present inventor has proposed this method by Japanese Patent Application No. 5-250131, Japanese Patent Application No. 5-292602, Japanese Patent Application No. 5-314266, Japanese Patent Application No. 5-351923.
It can be applied to any of the gas leakage region estimation methods proposed in Japanese Patent Application No. 5-351924 and Japanese Patent Application No. 6-148589.

[0033]

【Example】

(Embodiment 1) A preferred embodiment of the present invention will be described in detail with reference to FIGS.

An example of a system for realizing the method for estimating the gas leakage point and the gas leakage amount of the present invention is, as shown in FIG.
2) Gas detectors G (1) to G (M) and N (≧ 1)
Gas concentration data collection and storage device 1 and wind direction and wind speed data collection and storage device 2 which are connected to the data processing device 3 and each of which has gas horizontal direction anemometers B (1) to B (N). Also, the wind direction and wind speed data are input. The data processing device 3 inputs a gas flux alarm set value, gas detector and wind direction anemometer position data, and the like, and a keyboard 4 for performing various operations, gas detectors G (1) to G (M), and Anemometer B (1) -B (N)
No. and its position, the instrument position storage device 5, the gas flux for each gas detector number, the gas concentration, the wind direction, the wind speed, the standard deviation of the wind direction fluctuation, etc. at a required time interval in the past fixed time, for example, the past 1 An external storage device 6, an alarm device 7, a CRT display device 8, and a printer 9 that store time and time series
Is connected.

Wind direction anemometers B (1) to B (1) to B (1) to B (1) to B (1) to B (1) to B (1) to G (M), which are close to the respective gas detectors G (1) to G (M), provide approximate values of wind direction wind speeds at the respective positions.
(N) is selected so that the gas concentration data from each gas detector and the wind direction wind speed data have a one-to-one correspondence. In this case, a plurality of wind direction anemometers may be selected for one gas detector and the wind direction wind speed data may be interpolated or extrapolated depending on the positional relationship. Usually, N is preferably 1/50 or more of M. Further, the gas detector and the wind direction anemometer may be integrated so that the wind direction, the wind speed and the gas concentration of the air at the same place can be measured at the same time. In this case, the numbers M and N of these are M = N.

In this system, the measurement data of the gas detector and the anemometer that are constantly transmitted are converted into digital signals, and the data processing device 3 selects, stores and calculates data. ing. Further, since the gas concentration depends on the measuring method (equipment), the measuring time, etc., a certain amount of correction can be performed so that the equations (1) to (6) are satisfied.

The gas concentration data collecting / storing device 1 is adapted to collect and store the gas concentration data from the gas detector in time series at regular time intervals while updating the past data, and perform the above correction. Can be read out. Similarly, the wind direction and wind speed data collection and storage device 2 collects and stores the wind direction and wind speed data from the wind direction anemometer while updating it.

The data processing device 3 extracts the gas concentration data from the gas concentration data collecting device 1 and the wind direction and wind speed data corresponding to each gas detector from the wind direction and wind speed data, and obtains these gas concentration data and wind speed data. If they are in the measurable range, calculate the gas flux by multiplying them, and if the wind speed data is lower than the measurable range, calculate the gas flux by multiplying the gas velocity by the wind speed at the lower limit of the measurable value and the gas concentration. When the concentration data is lower than the measurable range, the gas concentration is calculated by multiplying the lower limit measurable gas concentration by the wind speed.

Here, since the gas detector generally has a poorer response characteristic than the anemometer, in order to adjust this, the detection delay due to the detection response between each gas detector and the corresponding anemometer is detected. The above process is performed with the gas concentration data traced back by a time difference corresponding to.

FIG. 3 shows an example of display by the CRT display device 8 of the present invention, showing a rectangular mount part which is a part of the plant, and the display of the equipment installed on the mount is omitted here. There is. Each gas detector G (1) to G (1
0) are arranged around the frame at intervals of 20 m. In this example, all the gas detectors G (1) to G (10) are integrated with the wind direction anemometers B (1) to B (10), and the wind direction anemometer and the wind direction corresponding to each gas detector are provided. The average value and the standard deviation value of are calculated based on the data from the respective anemometers.

When the gas flux exceeds the alarm set value, an alarm is issued except when the gas concentration is lower than the measurable range, and after the alarm is issued to the issued gas detector, this maximum value is set. The display of that direction is changed to, for example, red and blinked. Also, when only the gas concentration exceeds a certain value, an alarm is issued, and the display for the corresponding gas detector is changed to, for example, orange and blinked, and the conventional alarm is also used.

On the other hand, the CRT display device 8 has a gas detector whose gas concentration data and wind direction and wind speed data are in the measurable range. Is expressed by a quadratic equation of the direction, and a regression analysis is performed, and the gas leakage region is calculated and displayed based on the average value of the wind direction and the gas flux corresponding to the standard deviation of the wind direction giving the larger gas flux value. . In this case, the gas concentration depends on the measuring method (equipment), the standard deviation of the horizontal wind direction fluctuation, and the measuring time, so that a constant correction is made so that the equations (5) and (6) hold.

As shown by numerical examples below, the area shown in FIG. 3 is a space sandwiched between a pedestal with a height of 5 m and a pedestal at a position 4 m above it, and ethylene with a concentration of 100% leaks,
First, the gas detector G (2) detected the gas concentration data within the measurable range, and the corresponding wind direction wind speed data of the wind direction anemometer B (2) was obtained. The heights of the gas detectors from the floor are all 0.5 m, and the height of the gas leakage point is unknown at first, so the height is made the same as that of the gas detector for the time being. That is, T = 4 (m), Z1 = 0.5 (m), Z2 = 0.5,
Z = 0.5 (m) 20 data were obtained in 2 minutes, and the average value of the wind direction in the range measured from the quadratic equation obtained as a result of the regression analysis and the standard deviation thereof were α _{2, 1} = 30.0π / 180 σ _A2 = 4.4 degrees Further, the gas flux with respect to the average value of the wind direction was F _2,1 = 196 × 10 ⁻⁶ (m ³ / m ² · s).

Further, the wind direction obtained by subtracting the standard deviation value from the mean value of the wind direction and the gas flux at this time are α _2,2 = α _2,1 −σ A ₂ π / 180 = 25.6 π / 180 F _2,2 = 725 × 10 ⁻⁶ (m ³ / m ² · s). κ for σ _A2 = 4.4 degrees is from Table 1 κ = 1 Further, since the standard deviation σ _E of the vertical wind direction fluctuation is not measured, it is approximated as follows. σ _E2 = σ _A2 /2=2.2 degrees

The gas leakage region obtained by the method explained in the section of action from the values of the gas flux with respect to the above two directions of the gas flux is shown by a curve q212 in FIG.

In order to know the width due to the fluctuation of the data, when the standard deviation value of the gas flux value obtained as a result of the regression analysis is added to the above maximum value and the standard deviation value is subtracted, α _2,3 = 25.6π / 180, F _2,3 = 1233 × 10 ^-6
(M ³ / m ² · s) α _2,4 = 25.6π / 180, F _2,4 = 218 × 10
^-6 (m ³ / m ² · s), and the gas leakage region obtained by combining these data and the gas concentration data with respect to the average value of the wind direction is shown by curves q223 and q224 in FIG. The enclosed area is the gas leakage area estimated by the data of the gas detector G (2), and the color of this area is changed.

Next, the gas detector G (1) and the anemometer B
Based on the gas concentration data and the wind direction and wind speed data from (1), regression analysis was performed on 20 data obtained in 2 minutes, and the following results were obtained. α _1,1 = 45.0π / 180 σ _A1 = 5.0 degrees F _1,1 = 509 × 10 ⁻⁶ (m ³ / m ² · s) α _1,2 = α _1,1 + σ _A1 π / 180 = 50.0π / 180 F _1,2 = 844 × 10 ⁻⁶ (m ³ / m ² · s) Therefore, κ = 1, σ _E1 = σ _A1 /2=2.5 degrees When the standard deviation value is added to the maximum value and the standard deviation value is subtracted, α _1.3 = 50.0π / 180, F _1,3 = 1434 × 10 ⁻⁶
(M ³ / m ² · s) α _1.4 = 50.0π / 180, F _1,4 = 253 × 10
^-6 (m ³ / m ² · s).

With respect to the gas detector G (1), q112, q123 and q124 are newly obtained by the same method as described above,
As shown in FIG. 3, the areas where these and q223 and q224 intersect are displayed in different colors as estimated gas leakage areas.

The intersection of the curves q212 and q112 is the point with the highest probability of gas leakage in the gas leakage region. In this case, the coordinates of the gas leakage point P'are (30, 25,
It became 0.5).

When the gas leak amounts at the points P'are determined by the equation (4), they do not match. Therefore, the gas leak points P are determined by using the height Z as a variable. These are the horizontal coordinates (30,2 at Z = 1.0 m).
In 5), the agreement was obtained, and Q _1,1 = Q _2,1 = 0.015 (m ³ / s). That is, the three-dimensional position P of the gas leakage point is (30, 2
5, 1.0). Further, the coordinates of the gas leakage point P ′ estimated by the equation (8) are (30, 25, 0.5)
Then, in this case, the method was in agreement with the strict method, and all the gas leakage regions indicated by the curve q line were also in agreement.

Since the equation (8) is an approximate solution ignoring the reflection due to the upper and lower obstacles, if the influence of the reflection is small, the obtained gas leak point P'or P almost coincides with the position by the strict method, and the calculation time is therefore reduced. Has the advantage of being shortened. Further, the three-dimensional concentration distribution of the leaked gas can be displayed on the basis of the current value of the wind direction wind speed from the position coordinates of the gas leak point P and the gas leak amount.

When the respective gas leak points obtained from the data of a plurality of gas detectors are inside or in the vicinity of the target area, even if the alarm exceeding the gas flux alarm set value is not issued. The alarm sounds with a different tone. If the location of these gas leak points is far from the target area, gas generated during maintenance work at a distant plant, gas generated by evaporation of the solvent during painting, flammable vapor generated from the tank, etc. will be detected. There is a possibility that it is happening, and it is possible to immediately determine that the estimated gas leakage source position is distant, so the alarm is not particularly sounded.

Further, in this case, since the leaked gas concentration in the target area is clogged as a whole, the average value is obtained by the gas detector on the upstream side, and the concentration of the gas detector in that area is obtained. It can be corrected by subtracting that amount from. Even if a gas detector with high sensitivity is used, it is freed from the hassle of issuing an alarm unnecessarily, and in the case of danger, the sensitivity of the gas detector can be used to the maximum to estimate the gas leakage source early. It is a system that can.

(Embodiment 2) Another preferred embodiment of the present invention will be described in detail with reference to FIG.

In the second embodiment for realizing the method for estimating the gas leakage point and the gas leakage amount of the present invention, all the gas detectors G (1) to G (10) are the wind direction anemometer B (as in the first embodiment. 1) ~
Four gas detectors G (1), G (4), and G that are not integrated with B (10) and are located at the four corners as shown in FIG.
(7) and G (10) have four anemometers B (1) to B (B)
It is different from the first embodiment in that it is integrated with (4).

For the corresponding wind direction wind speed and the mean value and standard deviation value of the wind direction of each gas detector, the data from the two or three wind direction anemometers on the windward side of each gas detector are selected when the gas is detected. However, these are used by being interpolated. Also, if there is an obstacle on the windward side of each gas detector, there is an effect on the wind direction fluctuation and the wind speed fluctuation due to the turbulent flow generated secondarily by the obstacle, so that effect is shown in the section of the action. The standard deviation of the wind direction can be collectively corrected by the method. Others are the same as those in the first embodiment.

Now, the gas detector G (2) detects the gas concentration data, and the wind direction anemometers B (3) and B on the windward side thereof.
2 based on the wind direction and wind speed data obtained by interpolating the data of (4)
20 pieces of data were obtained per minute, and the average value of the wind direction in the range measured from the quadratic equation obtained as a result of the regression analysis and the standard deviation thereof were the same as in Example 1, α _2,1 = 30. It became 0π / 180 σ _A2 = 4.4 degrees. The gas flux obtained from the quadratic equation obtained as a result of the above-described regression analysis with respect to the average value of the wind direction is F _2,1 = 196 × 10 ⁻⁶ (m ³ / m ² · s) as in Example 1. Became.

Further, the azimuth α as seen from the gas detector G (2)
Since there is no obstacle in the direction of _2,1 , the wind direction obtained by adding the standard deviation value as it is to the average value of the wind direction and the gas flux at this time are α _2,2 = α _2,1 as in Example 1. _{-σ A2 π / 180 = 25.6π /} 180 F 2,2 = 725 × 10 -6 (m 3 / m 2 · s) became. From Table 1, κ = 1 for σ _A2 = 4.4 degrees
Becomes

Further, the standard deviation σ _E of the wind direction fluctuation in the vertical direction
Is not measured, and is approximated as follows. σ _E2 = σ _A2 /2=2.2 degrees The gas leakage region obtained by the method explained in the section of the action from the values of the gas flux with respect to the above two directions of the gas flux matches q212 in FIG.

Next, based on the gas concentration data from the gas detector G (1) and the wind direction and wind speed data obtained by interpolating the data of the wind direction anemometers B (3) and B (4), the data obtained in 2 minutes was obtained.
Regression analysis was performed on each piece of data, and the following results were obtained. α _1,1 = 45.0π / 180 σ _A1 = 4.4 degrees F _1,1 = 509 × 10 ⁻⁶ (m ³ / m ² · s)

As shown in FIG. 4, a diameter 2 centered at a position 20 m in the direction α _1,1 as viewed from the gas detector G (1) is used.
There is an upright cylindrical obstacle of m, and it was predicted from the Reynolds number for this cylinder that a strong vortex was generated behind the cylinder. In this positional relationship, the angle of viewing this cylinder from G (1) is 5.7 degrees.

Therefore, the angle of view is 1.A of αA ₁ = 4.4 degrees.
Since it becomes 3 times, this effect is σ by the method explained in the section of action.
Correct _A1 . In this case, σ _A1 is multiplied by about 1.15 and σ _A1 = 5
I took it. That is, σ _A1 = 5.0 degrees Therefore, α _1,2 = α _1,1 + σ _A1 π / 180 = 50.0π / 180 At this time, the following gas flux was obtained. F _1,2 = 844 × 10 ^-6 (m ³ / m ² · s) Therefore, κ = 1, σ _E1 = σ _A1 /2=2.5 degrees

These data are the same as in Example 1, and the gas leakage region corresponds to the curve q112 in FIG. Further, the same results as in Example 1 were obtained regarding the position coordinates of the gas leakage point P and the gas leakage amount. The curve q showing the other gas leakage regions also coincided with the first embodiment.

[0064]

As is apparent from the above description, according to the method for estimating the gas leakage region, the gas leakage point and the gas leakage amount according to the present invention, the local atmospheric turbulence due to various obstacles in the target area. Since the effect of flow diffusion can be directly observed and the gas leakage area can be estimated based on the data, the gas leakage area and the gas leakage amount can be accurately and quickly estimated.

[Brief description of drawings]

FIG. 1 is a diagram showing a positional relationship between a gas detector and a gas leak point.

FIG. 2 is a block diagram showing a configuration of a gas leakage system to which the present invention has been applied.

[Fig. 3] CR in gas leakage region and gas leakage amount estimation
The 1st example of a display on a T display device is shown.

[Fig. 4] CR in gas leakage region and gas leakage amount estimation
The 2nd example of a display on a T display device is shown.

[Explanation of symbols]

 1 gas concentration data collection storage device 2 wind direction wind speed data collection storage device 3 data processing device 4 keyboard 5 instrument position storage device 6 external storage device 7 alarm device 8 CRT display device 9 printer

Claims (3)

[Claims] 1. A gas leakage region is determined from gas concentration data from a gas detector and wind direction wind speed data from a wind anemometer installed in the vicinity of the gas detector based on a three-dimensional gas diffusion formula in atmospheric diffusion. A method for estimating, wherein the standard deviation of the gas concentration distribution in the gas diffusion equation is estimated from the wind direction fluctuation standard deviation from the anemometer for each azimuth, from the gas concentration data and the wind direction wind speed data. A method for estimating a gas leakage amount, which comprises estimating a gas leakage region. 2. A gas flux value is obtained by multiplying the gas concentration data and the wind speed data from the gas concentration data at the position of the gas detector and the wind direction wind speed data at the same position as the gas detector. The wind direction data is used as the gas flux direction, and a regression analysis is performed assuming that the logarithm of the gas flux value can be approximated by a function related to the direction of the direction, and the gas flux values obtained from the function for two directions, The method for estimating the gas leakage amount according to claim 1, wherein the gas leakage region is estimated from the standard deviation of the gas concentration distribution in the gas diffusion method obtained by estimating from the standard deviation of the wind direction data. 3. Gas concentration data from the gas detector and an anemometer near the gas detector in a place with few obstacles in the vicinity or a wind direction wind speed in a place with few obstacles on the windward side. From the wind direction wind speed data from the meter, the gas concentration data and the wind speed data are multiplied to obtain the value of the gas flux, and the wind direction data is taken as the direction of the gas flux, and the logarithm of the value of the gas flux relates to the direction. Regression analysis is performed assuming that the function can be approximated, and the values of the gas flux obtained from the function for two directions and the interior angles for which the horizontal and vertical widths of the obstacle for each direction are estimated from the position of the gas detector, respectively. The standard deviation of the horizontal and vertical wind direction fluctuations is divided, and if the quotient is 1 or more, a value within a predetermined value of the standard deviation of the horizontal and vertical wind direction fluctuations is estimated as the standard deviation. Estimation method for a gas leak amount of claim 1 and a standard deviation of at gas concentration distribution in the gas diffusion type and estimates the gas leakage area.