WO2013024875A1 - 降下煤塵の非定常発塵源位置の探索方法 - Google Patents
降下煤塵の非定常発塵源位置の探索方法 Download PDFInfo
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- WO2013024875A1 WO2013024875A1 PCT/JP2012/070759 JP2012070759W WO2013024875A1 WO 2013024875 A1 WO2013024875 A1 WO 2013024875A1 JP 2012070759 W JP2012070759 W JP 2012070759W WO 2013024875 A1 WO2013024875 A1 WO 2013024875A1
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- the present invention relates to a technique for searching a dust generation source of falling dust in the atmosphere.
- the present invention relates to a technique for analyzing measurement information for managing falling dust in the atmosphere.
- a model suitable for simulation is selected from input conditions such as atmospheric conditions, meteorological data, topographic data in the evaluation range of atmospheric pollutant diffusion, and the model is adapted to the input conditions in order to improve analysis accuracy.
- Select the adjustment input parameter from the measured value data in the database section create the input data from the analysis conditions by the model and the adjusted input parameter, perform simulation, and calculate the deviation between the result and emission source measured value data
- a technique for estimating the emission source corresponding to the data with the smallest deviation is disclosed.
- Patent Document 2 includes an input unit for inputting a normal emission amount released from an emission source during a period when the atmospheric chemical concentration measured in advance by the atmospheric observation station does not show an abnormally high concentration, and an atmospheric chemistry It has an output part that outputs the abnormal discharge amount of the chemical substance released from the discharge source during the period when the substance concentration showed an abnormally high concentration, and 2 of the discharge source (normal discharge amount-abnormal discharge amount)
- a technique for identifying an emission source that causes an abnormally high concentration of a chemical substance in the atmosphere by obtaining a solution that minimizes the sum of powers is disclosed.
- the amount of scattered dust and the direction of the wind are measured over an appropriate period at at least two or more arbitrary measurement locations A, B, and C around many dust generation locations a, b, c, d, and e.
- a first step of measuring at a predetermined time pitch a second step of calculating an average amount of scattered dust for each wind direction from the amount of scattered dust and the direction of wind obtained in the first step, and the plurality of dusts On the map including the occurrence points a to e and the above measurement points A to C, the third step for plotting a plurality of wind directions with a large average amount of dust scattered around each measurement point, and each measurement plotted in the third step
- the dust generation location where the intersection where the wind direction from the location intersects is located, or when the wind direction from each measurement location is almost the same, the dust generation location on the map existing in the wind direction is the source of the scattered dust.
- the fourth work to identify Techniques, including bets are disclosed.
- Patent Document 4 one or more portable self-supporting multi-sensing units that measure the air pollution status of multiple items are remotely controlled via a wireless or wired network to measure the air pollution status of multiple items.
- a technique for collecting and displaying the measurement data is disclosed.
- a plume type is usually used.
- a standard plume equation such as the following equation (1) is described as an atmospheric diffusion model of gas from a point source without adsorption on the ground surface.
- x, y, z three-dimensional orthogonal coordinates of the evaluation point (with the gas generation source as the origin) [m]
- x coordinate value corresponding to the direction in which the plume central axis extends on the horizontal plane
- y direction perpendicular to the direction in which the plume central axis extends on the horizontal plane (in the following explanation, this direction is referred to as “horizontal direction” as necessary.
- Coordinate value z vertical direction (in the following description, this direction will be referred to as “vertical direction” if necessary)
- C gas concentration at the evaluation point (x, y, z) [kg / M 3 or m 3 / m 3 ]
- Q P Gas generation amount [kg / s or m 3 / s]
- WS Wind speed [m / s]
- He Height of the gas generation source from the ground surface [m]
- ⁇ y , ⁇ z Gas plume diffusion width [m] (standard deviation of gas concentration distribution in the direction perpendicular to the gas flow, ⁇ y is the horizontal gas plume diffusion width, ⁇ z is the vertical gas plume diffusion Width).
- the gas plume diffusion widths ⁇ y and ⁇ z are defined as standard deviations of the gas concentration distribution in the direction perpendicular to the gas flow.
- Non-Patent Documents 1 and 2 describe the following equation (2) as a plume equation regarding a gas that is adsorbed on the ground surface and fine particles (SPM) having a low falling speed.
- V d deposition speed [m / s]
- V s Falling speed [m / s] (in case of SPM, 0 in case of gas)
- ⁇ y and ⁇ z are characteristic values for expressing the “plume diffusion width” in the direction perpendicular to the plume center axis, and the density when assuming a Gaussian concentration distribution in the direction perpendicular to the plume center axis. Is the distance between the point where is the standard deviation and the plume central axis.
- Non-Patent Document 3 discloses a plume equation that assumes a double Gaussian density distribution and uses a curve for the plume central axis.
- the characteristics common to these plume formulas are: first, the concentration value at a specific concentration evaluation point, the coordinate value of the evaluation point and the source, the generation speed (generation amount) at the source, and the weather such as wind direction and speed. It is expressed by a function expression such as a condition and the result is given uniquely. Second, in calculating the concentration, a central axis is assumed, and a “plume” that forms a high-concentration region characterized by “plume diffusion widths” ⁇ y and ⁇ z around the central axis is set. Comparing the plume equation with other methods, the numerical analysis method that calculates the concentration value at a specific concentration evaluation point by numerically solving multiple simultaneous physical equations calculates the concentration without assuming the plume.
- the “term multiplied by ⁇ ” in Equation (2) means that the gas or SPM is adsorbed above the ground surface by inverting the shape of the vertical distribution of gas or SPM symmetrically on the ground surface. The effect of adsorption on the ground surface of gas and SPM is adjusted by the magnitude of ⁇ .
- the “term multiplied by ⁇ ” in equation (2) is referred to as “ground surface reflection term” as necessary.
- Patent Document 6 discloses a funnel-shaped particle sampling port opened upward, an air channel circulating in the measuring device, and Using an inertia classifier placed in the middle of the air flow path, continuous mass measurement is performed for coarse particles and fine particles separately, and the transition of the falling speed of the falling dust in the atmosphere is measured from the measured value of the coarse particle mass.
- a continuous falling dust measuring device using a ⁇ -ray absorption mass measuring device to be calculated is disclosed.
- the first problem is that the target for searching for the source is not dustfall.
- the target for searching for the generation source is gas.
- the SPM is only included in the search target for the generation source.
- SPM is a much smaller particle compared to falling dust (by definition, SPM is a particle having a diameter of 10 ⁇ m or less), and its diffusion behavior in the atmosphere is substantial except that it causes minute particle sedimentation. It is equivalent to the behavior of gas.
- the falling dust is much larger dust particles than the SPM (the falling dust is a particle having a diameter of 10 ⁇ m or more), and its falling speed is extremely high. For this reason, the diffusion behavior of the dustfall in the atmosphere is greatly influenced by the falling speed of the particles. Therefore, the diffusion behavior of falling dust is greatly different from that of gas.
- the amount of dust fallen that the present application observes and manages is the amount of dustfall deposited on the ground surface.
- the concentration of gas and SPM at the evaluation point is the object of observation and management. For this reason, it is impossible to directly know the deposition rate of gas and SPM on the ground surface. Indeed, the above equation (2), since the deposition velocity V d is described, if it is possible to provide a deposition rate V d precisely, the gas and SPM concentration on evaluation point, deposition in the ground surface It can be converted into a quantity.
- Non-Patent Document 1 the SPM deposition speed V d varies greatly due to the influence of the ground surface condition and atmospheric turbulence. Further, a method for generally giving the gas deposition rate V d has not been developed. Therefore, it is extremely difficult to accurately give the value of the deposition velocity V d , and it is difficult to at least quantitatively target the dustfall by the techniques of Patent Documents 1 to 4.
- FIG. 14 is a diagram schematically showing a dust source search method in the conventional method (Patent Document 3).
- the dustfall evaluation point may be referred to as a dustfall management point, which have the same meaning.
- Patent Document 4 it is premised that a measuring instrument is provided in the vicinity of an assumed source. Thus, the source must be known in advance.
- Patent Documents 1 to 4 have a problem that the number of generation sources can be effectively applied only in an environment where the number of generation sources is extremely small or the generation amount of generation sources can be grasped sufficiently accurately. is there.
- the generation source targeted in the prior art is basically a steady generation source in which the generation amount does not vary with time, or the generation amount is slightly in the vicinity of the time average value. It is a quasi-stationary dust generation source that only fluctuates.
- the number of evaluation points is often set smaller than the number of generation sources from the viewpoint of economy. Even in this case, (unless the words that can adjust a generation quantity Q P parameter) if only the origin to the constant source, by using the measured values at the evaluation points in a number of different times Measured values greater than the number of sources can be ensured and optimization techniques can be applied.
- the amount Q P fluctuates unsteady large, in applying the technique of Patent Documents 1 and 2 for the non-stationary source, the generation amount Q P, forced to an adjustable parameter Absent. For this reason, when a large number of generation sources are to be searched, it is necessary to provide a very large number of evaluation points exceeding the number of generation sources, which is not practical from the viewpoint of economy.
- the source is searched by averaging the concentration data of SPM at discretely collected evaluation points within a period of two months or more. Therefore, the generation source is limited to a stationary generation source.
- Patent Document 4 since an evaluation point is arranged in the vicinity of an assumed generation source, an unsteady generation source can be searched in principle.
- this technology discloses a method for determining which of a plurality of sources is an excellent source when gases from a plurality of sources arrive at a specific evaluation point at the same time. Neither is it disclosed that an evaluation point is installed in the vicinity of all possible sources. Therefore, it is possible to search for an unsteady dust generation source with this technique only when the distance between the generation sources is so far as not to affect each other. That is, this technique can be applied only when the generation source and the evaluation point are substantially associated one to one.
- the generation amount is generally large and fluctuates with the passage of time. Therefore, the conventional technology that targets only a stationary source or a source that has a one-to-one correspondence between the source and the evaluation point has a problem that it cannot be sufficiently applied to an actual source search.
- soot dust when soot dust is radioactive, the radiation dose of soot ⁇ -rays, ⁇ -rays or ⁇ -rays can be measured by the methods disclosed in Patent Documents 7-9.
- JP 2003-255055 A Japanese Patent Laid-Open No. 2005-292041 JP 2004-170112 A JP 2003-281671 A JP 2007-122365 A JP 2008-224332 A Japanese Patent Laid-Open No. 8-327741 Japanese Unexamined Patent Publication No. 7-35900 JP 2009-63510 A
- Airborne particulate matter countermeasures study group (supervised by the Environmental Protection Agency, Air Quality Control Bureau, Air Regulation Division): Airborne particulate matter contamination prediction manual, Toyokan Publishing, 1997 Okamoto Junichi: Atmospheric environment prediction lecture, Gyosei, 2001 United States Environment protection agency: EPA-454 / R-03-004, 2004
- the present invention has been made in view of the above circumstances, and a dust generation source of falling dust in which the amount of dust generation (the generation speed of falling dust in the dust generation source) fluctuates non-steadily is around the dust generation source.
- the purpose is to identify efficiently and accurately based on the measured value of dustfall.
- the i t-th time in every time period Delta] t d as the time t d (i t), two different or more drop in dust evaluation point i, the time t d (i t -1) collecting the dustfall in the period T d (i t) is the period until the time t d (i t) from dustfall amount per unit time dust amount setting step and obtaining a measure of M; in the vicinity of the dustfall evaluation point i, continuously measuring the wind direction in the period T d (i t) in the time period Delta] t d shorter period Delta] t WINT than and the time period T d representative wind direction WD (i t) and the representative wind deriving step of deriving the (i t); in the vicinity of the dustfall evaluation point i, the period T d (i t) the time period ⁇ t continuously measuring the wind speed at WINT, representative wind speed W in the
- the first dust source search area center axis perpendicular cross-sectional area S p1 is a cross-sectional area of the first dustfall generation source search area in the vertical plane of the axis, with the first dustfall generation source search area width Of the second falling dust generation source search region in the vertical plane of the second central axis of the second falling dust generation source search region ⁇ (i N , i t ) including the coordinate point p.
- the coordinates The point p is determined to be a main unsteady dust generation source having a time scale equal to or greater than the time period ⁇ t g in the period T g (k), and is calculated in the dust generation amount calculation step. If the ratio of the assumed dust generation amount E 1 to the second assumed dust generation amount E 2 is outside the range of the predetermined upper and lower threshold values, the coordinate point p is set to the position in the period T g (k).
- the coordinate point p is determined not to be a main unsteady dust generation source having a time scale equal to or greater than the time period ⁇ t g and the coordinate point p is the first falling dust generation source search region and the second falling dust generation source search region. If it is not included in any of the above, it is necessary to determine the unsteady dust generation source of the falling dust at the coordinate point p.
- the period T d (i t ) includes two or more consecutive times t d ( when i t) a time for each time period Delta] t g containing a k-th time was t g (k), the evaluation period from the time t g (k-1) to time t g (k)
- T g (k) An arbitrary period included in the certain period T g (k) may be used.
- the first falling dust generation source search region ⁇ (i M , i max ) It is set as an unsteady falling dust search area for the first falling dust evaluation point i M in the period T g (k), and the second falling dust generation source search area ⁇ (i N , i t ) is set to the period T g may be set as the unsteady dustfall search area about the second dustfall evaluation point i N at an arbitrary time t d (i t) in (k).
- the representative wind direction WD (i t) may be derived as the mean value of the measured values of the wind direction in the period T d (i t).
- the representative wind speed WS (i t) may be derived as the mean value of the measured values of the wind speed at the period T d (i t).
- the particles falling velocity V s may be derived as the mean value of the measured values of the falling speed of the dustfall in the period T d (i t).
- the center axis of the falling dust generation source search region has the upwind direction of the wind direction as a horizontal component. And having a vertical gradient of a value V s / WS obtained by dividing the particle falling speed V s of the dustfall by the representative wind speed WS;
- the plume diffusion width ⁇ y in the horizontal direction at the first or second distance on the plume central axis is used as a horizontal component of the falling dust generation source search region width, and the first plume on the plume central axis.
- the plume diffusion width ⁇ z in the vertical direction at the second distance may be used as the vertical component of the falling dust generation source search area width.
- the plume diffusion widths ⁇ y and ⁇ z and the plume central axis Using the distance x from the generation source, the dust generation amount Q P , the representative wind speed WS, the constant B, and the plume range defined by using the plume diffusion widths ⁇ y and ⁇ z ,
- the following expressions (A) and (B) expressing the dust concentration C (x) at the distance x from the generation source on the central axis may be used as the plume expression.
- C (x) B (Q P / 2 ⁇ y ⁇ z WS) (within the plume range) (A)
- C (x) 0 (outside the plume range) (B)
- an ellipse having the short axis twice as short as the short axis may be a plume cross-sectional shape perpendicular to the plume central axis, and the inside of the ellipse may be within the plume range.
- the seventh aspect of the present invention in the method of searching for non-stationary dust source position of the dustfall according to the first aspect to sixth aspect, in the dustfall evaluation point i to the time period T d (i t) in A dust type classification step of measuring a radiation dose of the collected dust fall sample and classifying the fall dust sample for each dust species based on the measured intensity of the radiation dose; Of the dust sample, the mass of the dust fall in the part corresponding to any one of the dust species classified in the dust species classification step may be set as the dust fall amount M.
- the eighth aspect of the present invention in the method of searching for non-stationary dust source position of the dustfall according to the first aspect to sixth aspect, in the dustfall evaluation point i to the time period T d (i t) in A dust type classification step of classifying the dust species of the collected dust sample; And a dust generation source determination step of determining whether or not the dust evaluation point i is a dust generation source.
- the particle falling speed V s corresponding to the falling dust particles is the individual falling dust particles. Is compared with a given threshold value, the particle fall speed upper limit value V smax and the particle fall speed lower limit value V smin, and is classified into any one of two or more equivalent particle size categories, and arbitrarily A step of calculating a dust fall amount m j for the equivalent particle size category using an integrated amount of dust fall classified in the equivalent particle size category j ; an arbitrary dust fall evaluation point i A and an arbitrary equivalent particle size for classification j, unsteady dust source search area dustfall said any equivalent particle size range j in the period T d (i t) and gamma, as a starting point the dustfall evaluation point i a, the time t d It said in (i t) Upwind direction table wind direction WD, the non-stationary dust source search area and setting the horizontal component
- the tenth aspect of the present invention in the method of searching for non-stationary dust source position of the dustfall according to the ninth aspect, in the method of searching for non-stationary dust sources of dustfall in the period T d (i t) there, the representative wind direction WD, the representative wind speed WS, respectively, the time period T wind direction in d (i t), is the average value of the measured values of wind speed, the representative dustfall in any of the dustfall evaluation point i a the amount M (i a) is one obtained from the measurement value m of the dustfall amount in the dustfall evaluation point i a in the period T d (i t), in particular of the equivalent particle size range j, for different specific the dustfall evaluation point i A1, i A2 each other, the period T d (i t) nonstationary dust source search area gamma (i A1) of dustfall in sets gamma a (i A2) respectively A step of generating the unsteady dust Search region ⁇ (i A1), ⁇ of
- each time period Delta] t g comprising successive two or more of the time t d (i t) of, k-th time t g (k) to be provided, the time t g (k-1) and setting the period T g (k) is an evaluation period of time t g (k) from; the period T d wind direction measurements in (i t), the wind speed measurements, each wind direction divided with a given threshold, as well as classified in wind speed indicator, representing the wind direction indicator, each wind speed indicator, divided wind direction WD c a step of calculating a division wind speed WS c; at any dustfall evaluation point i a, the drop corresponding to the period T g period to measure the maximum dustfall amount m in (k) T d (i t ) measurement of dust amount, said section wind direction WD c, the partition wind speed WS c, the period g
- the point q is set as the dust generation related to the specific equivalent particle size classification. Otherwise, the point q is Thereby determined not to be a dust source for a particular equivalent particle size range, the estimated amount of dust generated E (q, i A) at the point q, and the estimated amount of dust generated E (q, i A1), E (q , I A2 ), and a step of calculating using i A2 ).
- the twelfth aspect of the present invention in the method of searching for non-stationary dust source position of the dustfall according to the ninth embodiment, trapped in the dustfall evaluation point i to the time period T d (i t) in A dust type classification step of measuring the radiation dose of the falling dust sample and classifying the falling dust sample for each dust type based on the intensity of the measured radiation dose; and the falling dust evaluation point i for each classified dust species And a dust generation source determination step of determining whether or not is a dust generation source.
- the thirteenth aspect of the present invention in the method of searching for non-stationary dust source position of the dustfall according to the ninth aspect to twelfth aspect, wherein capturing at dustfall evaluation point i to the time period T d (i t) in A dust type classification step for classifying the dust type of the collected dust sample; and for any one of the collected dust samples classified in the dust type classification step, the dust fall type And a dust generation source determination step of determining whether or not the evaluation point i is a dust generation source.
- the plume diffusion widths ⁇ y and ⁇ z and the generation on the plume central axis A plume center using a distance x from the source, a dust generation amount Q P , the representative wind speed WS, a constant B, and a plume range defined using the plume diffusion widths ⁇ y and ⁇ z
- the following expressions (A) and (B) expressing the dust concentration C (x) at the distance x from the source on the axis may be used as the plume expression.
- the units of the formulas (A) and (B) are all SI units, and ⁇ z is the upper end of the plume starting from the source in the vertical plane [the particle drop velocity in the particle size category
- the slope line is defined based on the lower limit value / representative wind speed, and the lower end of the plume is defined as the slope line defined based on the upper limit value of particle fall speed in the particle size category / representative wind speed.
- the width of the plume range in the direction perpendicular to the central axis of the plume.
- the present invention it is possible to efficiently and accurately search for dust generation sources of falling dust in which the amount of dust generation varies unsteadily by measuring the falling dust at a small number of evaluation points.
- the first feature of the embodiment of the present invention is that the dust generation source of the dust fall can be searched by directly measuring the dust fall at the dust fall evaluation point.
- the second feature of the present invention is that, in searching for the dust source of the falling dust, the dust source search area that extends in the windward direction from the falling dust evaluation point is correlated with the plume expression, thereby generating a dust source candidate. It is a point which can acquire the information of the amount of dust generation in.
- equation (4) becomes the following equation (6).
- the coordinate transformation from z to Z according to the equation (5) is tan ⁇ 1 (V s (particle fall velocity) / WS (wind velocity)) in the leeward direction with the generation source (dust generation source) as the origin. This corresponds to setting the central axis of the dust plume in the vertical plane at the depression angle and defining the concentration with this central axis as the Z axis.
- the plume range means a region on the central axis side from the position where the density when the density distribution in the plume vertical direction assumes a Gaussian distribution as shown in Equation (4), and the density indicates the standard deviation value of the density distribution.
- “within the plume range” means a region closer to the central axis than the plume diffusion width in a direction perpendicular to the central axis from the central axis of the plume.
- an ellipse having a major axis that is twice as long as ⁇ y or ⁇ z and a minor axis that is twice as long as the shorter axis may be a plume cross-sectional shape, and the inside of this ellipse may be within the plume range.
- the plume range may be more simply set as the range of the following formula (8).
- “outside the plume range” means an area other than the plume range.
- ⁇ y and ⁇ z are functions of the distance L 0 from the dust generation source and the time period ⁇ t d ( ⁇ y [L 0 , ⁇ t d ], ⁇ z [L 0 , ⁇ t d ]).
- ⁇ y and ⁇ z are based on Pasquill-Gifford described in Non-Patent Document 1 as numerical values or chart values obtained by fixing the period ⁇ t d (this is a reference period). Or by Briggs, etc., and the influence of the period ⁇ t d is corrected by an empirical formula.
- Non-Patent Document 2 the method of correcting the influence of the period ⁇ t d by the empirical formula is obtained by adding ([actually used ⁇ t d ] / [reference time ⁇ t d ]) P to the plume diffusion width ⁇ y. Multiplied by.
- the particle falling speed V s is determined as the terminal speed, so the falling dust amount M (x) is the following value obtained by multiplying the concentration C (x) by the particle dropping speed V s It can be expressed by Expression (9a) and Expression (9b).
- the local dust fall amount M (x) within the plume range is determined only by the dust generation amount Q P and the plume diffusion widths ⁇ y and ⁇ z .
- the values of the plume diffusion widths ⁇ y and ⁇ z can be expressed as a function of x and weather conditions by, for example, the Pasquill-Gifford equation described in Non-Patent Document 1. Therefore, under a certain dust source condition and a certain meteorological condition, the amount of dust fall M (x) at a specific dust fall evaluation point is expressed only by the distance x from the particular dust source. Can do.
- Equation (9a) the existence range of the dust generation source at a specific falling dust evaluation point will be considered using Equation (9a) and Equation (9b).
- the wind direction WD is the positive direction of x ′.
- the plumes ⁇ (i o1 ) and ⁇ (i o2 ) are arranged so that the negative end of y ′ and the positive end of y ′ in plume ⁇ (i o2 ) pass through the origin O. Yes.
- the plume alpha (i o1), the arrangement of the alpha (i o2) is, from x set to L 0 has been dust source i o1, i o2, plume ⁇ (i o1), ⁇ ( i o2) is lowered This is the limit position where the dust evaluation point i M can be reached. That is, the position of the dust generation source i o1 is the limit position on the plus side of y ′, and the position of the dust generation source i o2 is the limit position on the minus side of y ′.
- Hatsuchirigen i o1, i o2 range Is a region ⁇ (i M , i t ) (between a line passing through the origin O and the point of the dust source i o1 and a line passing through the origin O and the point of the dust source i o2. (Areas shown with diagonal lines).
- This region ⁇ (i M , i t ) is the dust source search range.
- FIG. 6 is a diagram obtained by projecting plumes ⁇ (i o3 ) and ⁇ (i o4 ) emitted from i o4 on the same vertical plane as the dustfall evaluation point i M.
- the dust generation source search region ⁇ (i M , i t ) is set by the same method as described with reference to FIG. At this time, the width of the dust generation source search region ⁇ (i M , i t ) is represented by the diffusion width ⁇ z (x ′).
- this invention is not limited to using the plume type
- formula of Formula (9a) and Formula (9b) when precise measurement is performed in advance and the influence of the ground surface reflection term can be accurately expressed, the term of ⁇ z in equation (9a) is appropriately set based on the plume equation with the ground surface reflection term left. Correction may be added.
- the third feature of the embodiment of the present invention is that it is not always necessary to assume a dust generation source and a dust generation amount in advance. Since an actual dust source often does not know all of its position and dust generation amount in advance, the method of the embodiment of the present invention is advantageous in that it can search for a dust source in accordance with reality. is there.
- the fourth feature of the embodiment of the present invention is that an unsteady dust generation source can be specified.
- the main period in the time zone is acquired every acquisition period of the measurement value of the amount of dustfall or every time of several consecutive periods of the acquisition period of the measurement value of the amount of dustfall.
- the source of dust generation can be specified. Therefore, this can be grasped if it is an unsteady dust generation source that fluctuates on a time scale that is equal to or more than several cycles of the acquisition period of the measured value of the amount of dustfall.
- the number of falling dust evaluation points necessary for identifying the unsteady dust generation source may be sufficiently smaller than the number of potential dust generation sources.
- the fifth feature of the embodiment of the present invention is that the falling dust collected at the evaluation point is classified as radioactive falling dust or non-radiating falling dust, so that the unsteady dust generation source of radioactive falling dust is changed to the radioactive dust generation source. It is a point that can be specified by using the falling dust measurement data in the distance without approaching.
- the falling dust amount measuring means measures the falling dust amount (the mass of the falling dust) for each time period ⁇ t d (hereinafter, “time period” is abbreviated as “period” if necessary).
- the time output of the measured value of the dustfall amount is t d (i t).
- Time t d (i t -1) from the time t d (i t) until the time (period) is defined as "the period T d (i t)".
- i t is an integer that increases by 1 with the time when the measurement of dustfall started being set to 0.
- a time period composed of n t consecutive “periods T d (i t )” is defined as “period T g (k)”, where n t is a natural number of 2 or more.
- the “period T g (k)” the starting point of the time the time t g of (k-1), the i t at this time is 0.
- “period T g (k)” of the end-point of time the time t g (k), the i t at this time is n t.
- k is an integer that increases by 1 with the time when the measurement of dustfall started being set to 0.
- the period Delta] t g for example, can be adopted 6 cycles of the periodic Delta] t d (time period Delta] t d is 10 minutes, the period Delta] t g is 1 hour).
- Dust source can be identified in the present embodiment is a non-stationary dust source scale is more periodic Delta] t g time. Therefore, setting the period ⁇ t g to be extremely long is not preferable because the number of unsteady dust generation sources that can be specified decreases. In general, weather conditions differ greatly between daytime and nighttime. For this reason, since many unsteady dust generation sources show a time scale of half a day or less, the period ⁇ t g is preferably 12 hours or less. Of course, this is not the case when it is previously known that the time scale of the unsteady dust generation source is 12 hours or more.
- the three-dimensional region may implement the search for dust source, x, y, and set the z becomes orthogonal coordinate system, on each coordinate axis, respectively n x, n y, and n z number of coordinate components provided, it will be representative of the three-dimensional space with n x ⁇ n y ⁇ n z pieces of coordinate points p.
- the coordinate point p is, i x th coordinate axes components, respectively, i y th represents the coordinate point is i z th.
- each coordinate point is expressed as a position vector from the origin O as Sc (i x , i y , i z ) using the order of the coordinate components i x , i y , i z on each coordinate axis. .
- one of three modes of “dust generation source”, “not a dust generation source”, and “undecided” is set as a dust generation source determination mode.
- the dust generation source search device is realized by using, for example, an information processing device (for example, a commercially available personal computer (PC)) including an arithmetic device such as a CPU, a memory, an HDD, and various interfaces.
- an information processing device for example, a commercially available personal computer (PC)
- PC personal computer
- arithmetic device such as a CPU, a memory, an HDD, and various interfaces.
- the flowchart of FIG. 3 is translated into a computer program that can be executed using a programming language such as C language and stored in advance in an HDD or the like.
- the executable computer program stored in the HDD or the like is read and activated by an arithmetic device such as a CPU, and based on a command of the executable computer program
- the calculation is realized by sequentially executing the calculation by a calculation device such as a CPU.
- the start timing of the dust generation source search process may be such that the executable computer program may be started manually, or may be automatically started periodically.
- the dust source search device of the present embodiment searches for a dust source of falling dust in the “period T g (k)” at a certain time.
- necessary input information such as position information such as the falling dust evaluation point / coordinate point, measured values such as the amount of falling dust, wind direction, wind speed, and analysis values related to the dust type are connected to the information processing device.
- position information such as the falling dust evaluation point / coordinate point
- measured values such as the amount of falling dust, wind direction, wind speed, and analysis values related to the dust type are connected to the information processing device.
- a keyboard, console screen, or the like it is possible to input manually in advance.
- the input information that has been input is stored in an HDD or the like, and is appropriately read out as the generation source search process proceeds.
- the unsteady dust source determination result and the calculation result such as the dust generation amount with respect to the calculated specific coordinate point can be stored in the HDD or the like and displayed on the console screen or the like.
- step S1 the dust source search device initializes the dust source judgment mode to “undecided” at all coordinate points p.
- step S2 the dust generation source search device determines the positions of all the falling dust evaluation points i (where n M ⁇ i ⁇ 1) in the horizontal plane (for example, the ground altitude of 1.5 m) in the coordinate system. It is calculated as a position vector P (i) indicating the position from the origin.
- step S3 dust source searching apparatus, a "representative wind speed WD (i t) in the" period T g (k) "All" time period T d (i t) "included in the representative wind WS and (i t), dustfall amount M (i, i t) at all dustfall evaluation point and, for particles falling velocity V s of the dustfall (i, i t) "setting (input).
- a dust amount setting process, a representative wind direction derivation process, a representative wind speed derivation process, and a particle fall speed derivation process are executed.
- the wind direction and the wind speed can be values measured by using a commercially available propeller type wind direction anemometer with a period ⁇ t wint shorter than the period ⁇ t d (for example, a period of 1 second).
- the spatial resolution of the wind direction is, for example, 1 ° intervals.
- Representative wind direction WD (i t), representative wind speed WS (i t) may be, for example, using the average value of "wind direction measurements and speed measurements" in the corresponding "period T d (i t)".
- the vicinity of the falling dust evaluation point may be a range in which the wind direction and the wind speed have a high correlation with the wind direction and wind speed above the falling dust evaluation point. For example, a horizontal distance within 1 km from the falling dust evaluation point can do. In areas where the topography is monotonous and the wind direction / velocity distribution is small, the horizontal distance may be longer.
- the height of the wind direction / velocity measurement point can be 10 m from the ground surface, which is the measurement height recommended by the Japan Meteorological Agency. When the assumed height of the dust generation source is sufficiently higher than 10 m, the height between the ground surface and the height of the dust generation source may be set as the measurement point height.
- a sheet-like laser beam is continuously irradiated in the horizontal direction at the bottom of the container, and the dustfall occurs when the dustfall passes through this laser light.
- a method such as detecting scattered light with a photodetector can be employed.
- the falling time corresponding to the time when 50% of the falling dust particles reach the bottom of the container It can be adopted as the falling speed of the falling dust particles related to the falling speed V s of the falling dust particles.
- the particle falling speed V s of the falling dust particles can be calculated simply by measuring the particle size distribution of the falling dust sample. it can.
- the following equation (10) of the Stokes end velocity can be used.
- V s ⁇ 4gD p ( ⁇ p - ⁇ f) / 3 ⁇ f C R ⁇ 1/2 ⁇ (10)
- step S4 the dust generation source search device sets the “dust generation source search region ⁇ (i, i t ) for each falling dust evaluation point i” at all the falling dust evaluation points i to “period T g (k ) "At all times t d (i t ).
- a dustfall generation source search region setting step is executed.
- FIG. 4 is a diagram showing an example of a dust source search range ⁇ (i, i t). With reference to FIG. 4, dust source search range ⁇ (i, i t) an example of a setting method will be described.
- ⁇ (i M , i t ) is the same as the dust generation source search region ⁇ (i M , i t ) decomposed and displayed for each coordinate component in FIGS. It is expressed in a single figure.
- two dustfall evaluation points i M and i N are installed on the ground surface on the absolute coordinates (x ′, y ′, z), and these dustfall assessment points i M and i N are used as representative points.
- a plurality of dust sources search area ⁇ (i, i t) if there is, there may occur a plurality of dust sources search area ⁇ (i, i t) a common region 41 between .
- step S5 dust source searching apparatus, lowering the dust evaluation point i, "" period T g maximum dustfall amount in (k) "M (i, i t) to become time t d ( and M max (i) is a dustfall amount of i t), and i max (i) is the i t in this case, the representative wind direction WD max ⁇ representative wind speed WS max at the time t d (i t) "a calculate.
- the maximum dust fall information deriving step is executed.
- step S6 dust source searching apparatus, as one of dustfall evaluation point i M, selects the dustfall evaluation point i unselected.
- step S7 the dust source search device selects an unselected coordinate point p.
- step S8 dust source searching apparatus, the position vector Sc of the coordinate point p (i x, i y, i z) calculated.
- Position vector Sc of the coordinate point p is a starting point the origin of the coordinate axes, i x th coordinate axes components, respectively, i y th, i z th coordinate axis division points become point (i.e., p point) to the end point of the Set to
- ⁇ (i M , i max ) is defined as the first unsteady falling dust search area as “the only unsteady falling dust search area for the falling dust evaluation point i M ” in the “period T g (k)”. To do.
- step S9 the dust generation source search device selects the other falling dust evaluation point i N different from the falling dust evaluation point i M.
- step S10 the dust generation source search device determines whether or not the dust fall evaluation point i M selected in step S6 and the dust fall evaluation point i N selected in step S9 are at the same position. judge. If the result of this determination is that the falling dust evaluation point i M and the falling dust evaluation point i N are at different positions, the process proceeds to step S11. On the other hand, when the falling dust evaluation point i M and the falling dust evaluation point i N are at the same position, steps S11 to S20 are omitted and the process proceeds to step S21 described later.
- step S11 dust source searching apparatus, among the "period T g (k)" in the time t d (i t), selects the unselected time t d (i t).
- step S12 the dust source search device determines that the coordinate point p selected in step S7 is the first dust source search range ⁇ (i M , i max ) and the second dust source search range. It is determined whether or not a dust generation source determination condition that the dust generation source determination mode is a mode other than “not a dust generation source” is included in both of ⁇ (i N , i t ).
- the coordinate point p selected in step S7 may be a dust generation source.
- the state that satisfies this dust generation source determination condition is in the common region 41 (region shown by the oblique lines) of the two dust source search regions ⁇ (i M , i t ) and ⁇ (i N , i t ) in FIG. Corresponds to the state where the coordinate point p exists.
- the process proceeds to step S13.
- steps S13 to S20 are omitted and the process proceeds to step S21 described later.
- the dust generation source search device is the (shortest) distance L d (i M ) between the coordinate point p selected in step S7 and the one dustfall evaluation point i M selected in step S6. Similarly, the (shortest) distance L d (i N ) between the coordinate point p selected in step S7 and the other falling dust evaluation point i N selected in step S9 is calculated.
- the calculation method of the distance L d (i N ) between the coordinate point p and the falling dust evaluation point i N is also the same. In the present embodiment, for example, a distance calculation step is executed in step S13.
- step S14 dust source searching apparatus, "dustfall evaluation point at the coordinate point p selected in step S7 i M, dust source search area about i N ⁇ (i M, i t), ⁇ ( i N , i t ) of the central axis vertical sectional areas S p1 and S p2 ”are calculated.
- the calculation method of the central axis vertical cross-sectional areas S p1 and S p2 of the dust generation source search regions ⁇ (i M , i t ) and ⁇ (i N , i t ) is, for example, as follows.
- step S15 the dust generation source search apparatus calculates “assumed dust generation amounts E 1 and E 2 at the coordinate point p selected in step S7” estimated from the dustfall evaluation points i M and i N , respectively. calculate.
- the assumed dust generation amounts E 1 and E 2 are calculated using, for example, the following equations (11a) and (11b).
- E 1 B 1 Sp 1 M max (i M ) (11a)
- E 2 B 1 Sp 2 M (i N , i t ) (11b)
- B 1 is a coefficient.
- Expressions (11a) and (11b) correspond to the fact that the local concentration is proportional to the amount of generation at the generation source and inversely proportional to the local plume cross-sectional area in the general plume expression. That is, if the coordinate point p selected in step S7 is a dust generation source, a concentration that is inversely proportional to the plume cross-sectional area at the falling dust evaluation points i M and i N is detected. That is, for a certain detected concentration, the larger the assumed plume cross-sectional area, the greater the amount of generation at the corresponding source. Therefore, the generation amount at the generation source should be proportional to the plume cross-sectional area at the falling dust evaluation points i M and i N.
- B 1 in the equations (11a) and (11b) is a coefficient that should be changed by a number of parameters such as weather conditions.
- a number of parameters such as weather conditions.
- B 1 can be set as a constant as a simple method. In the present embodiment, for example, in this step S15, a dust generation amount calculating step is executed.
- the dust generation source search device calculates a ratio R between the assumed dust generation amounts E 1 and E 2 .
- the ratio R between the assumed dust generation amounts E 1 and E 2 may be E 1 / E 2 or E 2 / E 1 .
- the dust generation source search device determines whether or not the coordinate point p selected in step S7 is a dust generation source.
- the dust source search device determines whether or not the ratio R of the assumed dust generation amounts E 1 and E 2 is within a preset upper and lower threshold value range (R max ⁇ R ⁇ R min ). Determine.
- R max ⁇ R ⁇ R min a preset upper and lower threshold value range
- the ratio R between the assumed dust generation amounts E 1 and E 2 is within the preset upper and lower threshold values
- it is determined that the coordinate point p selected in step S7 is a “dust generation source”. Is done.
- the coordinate point p selected in step S7 is determined as “not a dust generation source”.
- the basis of this judgment method is as follows.
- the fluctuation in the amount of dust generated from an unsteady dust generation source whose time scale is equal to or greater than the period ⁇ t g is sufficiently small within the “period T g (k)”. Therefore, as long as a search is made for a dust generation source having a larger dust generation amount than other dust generation sources, that is, a main dust generation source, the falling dust generated from the main dust generation source is “period T g (k ) "Is considered dominant at all falling dust evaluation points i that can be reached.
- the amount of falling dust observed at these falling dust evaluation points i is determined by the dust source ( According to a function of the distance between the coordinate point p) and each of the dustfall evaluation points i (ie, the plume equation), they should exhibit a constant ratio. Therefore, the coordinate point p satisfying this condition is highly likely to be a main dust source. Therefore, when the ratio R between the assumed dust generation amounts E 1 and E 2 is within the preset upper and lower threshold values, it is determined that the coordinate point p selected in step S7 is a “dust generation source”.
- the coordinate point p selected in step S7 is “period T g Even in the case of the coordinate point p existing at a position where the falling dust can reach the plurality of evaluation points i in (k) ”, there is a high possibility that it is a false dust generation source. Therefore, when the ratio R of the assumed dust generation amounts E 1 and E 2 is outside the range of the preset upper and lower threshold values, it is determined that the coordinate point p selected in step S7 is not the “dust generation source”.
- step S7 determines whether the coordinate point p selected in step S7 is a dust generation source. If the coordinate point p selected in step S7 is not a dust generation source, the process proceeds to step S20 described later.
- step S12 and step S17 a dust generation source determination step is executed.
- step S18 the dust source search device sets the dust source determination mode of the coordinate point p selected in step S9 to “dust source”.
- the dust generation source search device calculates an estimated dust generation amount at the coordinate point p determined to be a “dust generation source”.
- the estimated dust generation amount can be, for example, an average value of all assumed dust generation amounts E used for the dust source determination (step S17) at the coordinate point p determined to be the “dust generation source”. . And it progresses to step S21 mentioned later.
- step S20 the dust source search device sets the dust source determination mode of the coordinate point p selected in step S7 to “not a dust source”. Then, the process proceeds to step S21.
- step S21 dust source searching apparatus determines whether selected "period T g (k)" all the time t d (i t) in the. As a result of the determination, if you do not select the "period T g (k)" all the time t d (i t) in the process returns to step S11. On the other hand, when selecting "period T g (k)" all the time t d (i t) in, the process proceeds to step S22.
- step S22 the dust generation source search device determines whether or not all the falling dust evaluation points i have been selected as the other falling dust evaluation point i N. As a result of the determination, as the other dustfall evaluation point i N, if not select all of dustfall evaluation point i, the process returns to step S9. On the other hand, when all the falling dust evaluation points i are selected as the other falling dust evaluation point i N , the process proceeds to step S23.
- the dust generation source searching device determines whether or not all coordinate points p have been selected. If all the coordinate points p are not selected as a result of this determination, the process returns to step S7. On the other hand, if all coordinate points p are selected, the process proceeds to step S24.
- step S24 the dust generation source searching device determines whether or not all the falling dust evaluation points i have been selected as one of the falling dust evaluation points i M. The result of this determination, as one dustfall evaluation point i M, if not select all of dustfall evaluation point i, the process returns to step S6. On the other hand, when all the falling dust evaluation points i M are selected as one falling dust evaluation point i M , the process proceeds to step S25.
- step S25 the dust source search device displays the position of the dust source and the estimated dust generation amount in the dust source. And the process by the flowchart of FIG. 3 is complete
- the second, the third step, "the period T g (k)" can be performed for all time t d (i t) in respect to particular coordinate points p, a specific time t d (i
- the determination result as to whether or not it is a dust generation source at t ) can be the determination result as to whether or not it is a dust generation source representing “period T g (k)”.
- the coordinate points p selected in step S7 it is determined as "not a dust source” at any time t d (i t), the coordinate point p in the "period T g (k)" is It is determined that it is not the main dust generation source.
- the coordinate point p is determined to be "Hatsuchirigen", and, when it is determined as "not a dust source” at any time other than it The coordinate point p is determined to be “the main dust generation source in the period T g ”.
- the dust falling evaluation points i M and i N and the coordinate point p may be changed as necessary to independently determine whether or not the dust generation source is present. .
- the initial value “undecided” remains as the dust source determination mode.
- the source search region is extended to the upwind direction from the evaluation point p, by introducing the concept of the plume type, time scale is not less than the period Delta] t g, the dustfall generation source It becomes possible to accurately identify the dust generation amount at the position and the generation source. Therefore, it becomes possible to efficiently and accurately search for dust sources including unsteady dust sources by measuring the amount of dust fall at a small number of dust fall evaluation points.
- the dust source search region is not a three-dimensional region as in the first embodiment, but in a horizontal plane (two-dimensional By setting within the region, it is possible to simplify the process of searching for a dust source, and to reduce the impossibility of calculation required for searching the dust source.
- the dust source search device tilts the central axis of the dust source search region ⁇ (i M , i t ), ⁇ (i N , i t ) in the vertical direction.
- the vertical diffusion width ⁇ z is omitted (the elevation angle ⁇ is 0 ° and the diffusion width ⁇ z is 0), and the dust generation source search regions ⁇ (i M , i t ) and ⁇ (i N , i t ) are 2D.
- the vertical components are also omitted from the position vectors P and Sc in steps S2 and S8 to form a two-dimensional vector.
- step S14 dust source searching apparatus, "dustfall evaluation point at the coordinate point p selected in step S7 i M, dust source search area about i N ⁇ (i M, i t), ⁇ ( i N , i t ) of the central axis vertical cross-sectional areas S p1 and S p2 ”must be calculated.
- the center axis vertical cross-sectional areas S p1 and S p2 of the dust generation source search areas ⁇ (i M , i t ) and ⁇ (i N , i t ) relating to the dustfall evaluation points i M and i N have been calculated
- a cross-sectional area of a circle having a radius of “horizontal diffusion width ⁇ y [L d ]” of the falling dust particles at the distances L d (i M ) and L d (i N ) can be used.
- wind direction and wind speed varies generally.
- the second dust source search region ⁇ (i N , i t at another evaluation point i N is used. ) And the first source of dust generation.
- measured value M (i N, i t) by using a "first, second dust source search area ⁇ (i M, i t) , ⁇ (i N, i t) intersection of liable Therefore, it is possible to determine the presence or absence of a dust source at a larger number of coordinate points p. In addition to being able to reduce the “undecided” coordinate points p, the number of dust source Can search.
- the wind direction WD (i N , i t ) may not be the wind direction when the maximum amount of dust fall is measured at the dust fall evaluation point i N as in the conventional method.
- the wind direction WD (i N , i t ) may not be the wind direction when the maximum amount of dust fall is measured at the dust fall evaluation point i N as in the conventional method.
- the wind direction since there is an estimated value of the dust generation amount in the dust source search region based on the plume formula, whether or not the wind direction is the maximum dust fall amount as in the conventional method.
- information on the absolute value of the measured value of the amount of dustfall in a specific wind direction that is, not relative information on the amount of dustfall in other wind direction conditions
- FIG. 14 is a schematic diagram for explaining a generation source search method in the conventional method.
- the intersections 6, 7, and 8 of the source search lines 2, 3, and 4 are regarded as dust generation sources.
- the conventional technology lacks information on the amount of generation on the source search lines 2, 3, and 4. For this reason, no further information can be obtained as to whether these individual intersections 6, 7, 8 are valid as dust sources.
- the intersection point 6 may actually be a major source, but apparently occurs only at this intersection point 6 due to the influence of the other major dust sources on the falling dust evaluation points i 1 and i 2 .
- the source search lines 2 and 3 may have just intersected (for example, the main generation source related to the falling dust evaluation point i 1 is the intersection 7 and the main generation source related to the falling dust evaluation point i 2 is the intersection 8. Or, it may be an unknown source that is located closer to the falling dust evaluation point i 2 than the facility (where dust (SPM) is generated) c). In the conventional method, it is impossible to determine which of these is a true dust generation source. In particular, when an intersection of the source search lines 2, 3, 4 occurs at a point that is not assumed to be a source (for example, the intersection points 7, 8), is this intersection point an unknown dust source, or It is not possible to identify whether it is just an apparent source search line intersection (ie, not a source). Therefore, the dust source is over-detected (when all intersections are determined to be sources), or unknown dust sources cannot be detected (sources at points not previously assumed as sources) It was inevitable that one of the troubles of (determining all intersections of search lines as false) would occur.
- FIG. 5 is a diagram schematically illustrating an example of a method for searching for a dust generation source in the embodiment of the present invention.
- the estimated dust generation amount E (p 1 , p 1 , for the falling dust evaluation points i 1 and i 2 of the coordinate point p 1 respectively.
- the dust source can be determined quantitatively.
- the conventional method can only search for the source in the direction in which the concentration detection amount by wind direction shows the maximum value (at least the maximum value).
- the measurement period since the measurement period is relatively short, fluctuations in the wind direction during this period are generally limited. Accordingly, it is practically impossible to obtain concentration measurement values under all wind direction conditions at each dustfall evaluation point. For this reason, depending on the combination of the main source, the dustfall evaluation point, and the wind direction range from which the measured value can be obtained, the wind direction that should originally exhibit the maximum concentration value at the specific dustfall evaluation point is during the measurement period. Therefore, the source search may not be possible (or false identification). Originally, even concentration measurements under limited wind direction conditions should have some information about the source.
- a dust source search can be performed in the direction in which the wind direction data exists (for example, if a source search line such as the source search line 5 shown in FIG. 14 can be set), at least another dust fall evaluation Information useful for identifying the source at a point may be provided.
- a source search line such as the source search line 5 shown in FIG. 14 can be set
- FIG. 6 is a diagram schematically illustrating an example of a method for setting the dust generation source search region in a direction other than the wind direction indicating the maximum concentration value.
- the dust generation source search region ⁇ (i, i t ) is obtained by using the particle size analysis result of the falling dust sample obtained at the falling dust evaluation point i. , Expanded on a three-dimensional space. For this reason, in the conventional method, even if the dust source search ranges seem to intersect each other at first glance in the plan view as shown in FIG. There are many cases where a common area does not exist.
- the position of the dust generation source and the amount of dust generation at the dust generation source can be specified with higher accuracy.
- a known method can be used for measuring the radiation intensity of the falling dust.
- the methods described in Patent Documents 7 to 9 can be used.
- the classification method of dustfall sample based on the radiation intensity for example, each of the periods T d (i t) (the time t d (i t -1) at time t d (i t) to the time (period))
- Individual falling dust particles in the sample collected at the evaluation point are separated one by one and their respective radiation intensities are measured. If the radiation intensity is equal to or higher than a predetermined threshold, the falling dust particles having the radiation intensity are separated. It can be classified as radioactive fallen dust and the others can be classified as non-radioactive dustfall.
- the total mass of this sample is measured as the amount of dustfall.
- measure the radiation intensity of the entire sample of the specific dust particles collected and if the radiation intensity is greater than or equal to a predetermined threshold, the mass of the entire sample is taken as the mass of radioactive dust, otherwise Alternatively, the mass of the entire sample may be the mass of the non-radioactive falling dust sample.
- the mass of the radioactive dustfall thus obtained (or the mass of non-radioactive dustfall) is set as the dust fall amount M (i). Then, any one of “dust generation source”, “not a dust generation source”, and “undecided” is set for radioactive dustfall (or non-radiative dustfall).
- an unsteady dust generation source of radioactive dust fall can be specified using the dust fall measurement data at a distance without approaching the radioactive dust source.
- a keyboard or console screen connected to the information processing apparatus is used. And can be set (input) manually in advance.
- the classification of falling dust is not limited to radioactive substances, but the falling dust sample collected at the evaluation point is classified by dust type, and whether any of the classified dust types is a source of dust. It may be determined.
- the classification of the dust species a known method such as classification based on the analysis result of the physical properties of the individual falling dust species can be used.
- the component composition ratio of each falling dust sample may be obtained quantitatively using EPMA, which is an electron microscope, and classified for each dust type based on this component structure.
- Dust dust collected at the evaluation point is identified by type, and individual fallen dust particles (samples) or the entire fallen dust particles (samples) are identified by type of fallen dust, and individual fallen dusts are identified.
- Unsteady dust generation sources can be searched for.
- a method for determining the soot species classification i s of the particles may be analyzed physical properties of the T g (k) individual dustfall particles collected in the period.
- particle property analysis methods include, for example, embedding all particles in a resin or the like, exposing the particle cross-section by polishing, and irradiating the particle cross-section while scanning X-rays, and reflecting the reflection characteristics of the element in the particle. EPMA can be applied.
- the following method for easily determining the dust type when it is clear in advance that the dust type is a falling dust derived from a steelmaking plant by the blast furnace method May be used.
- a magnetic force is applied to the collected falling dust sample, and the falling dust is separated into a magnetic falling dust that magnetizes the magnet and a non-magnetic falling dust that does not adhere to the magnet.
- the magnet used here is a permanent magnet such as an electromagnet or a neodymium magnet capable of holding a magnetic force of about 0.1 T to 0.4 T on the surface. Then, a magnetic force is applied to the collected dust falling sample to separate the dust falling into a magnetic falling dust that magnetizes the magnet and a non-magnetic falling dust that does not adhere to the magnet.
- iron ore and steelmaking slag generally containing a large amount of iron
- coal containing a very small amount of iron is not magnetized. Therefore, individual dust can be separated into magnetized dust and non-magnetized species dust.
- Representative types of dust fallen dust derived from blast furnace steel production plants include iron dust such as iron ore and iron powder, carbon dust such as coal and coke, blast furnace slag dust, and steelmaking slag dust. Is something. Iron-based dust and steelmaking slag dust correspond to magnetized dust, and carbon-based dust and blast furnace slag dust correspond to non-magnetized dust.
- dust particles are two-dimensionally dispersed and arranged so that the magnetized dust sample and the non-magnetized species dust sample are not in contact with each other, and then they are put on a commercially available digital camera. Etc. to obtain a particle image.
- the image of the magnetized dust sample will be referred to as “image of the magnetized dust sample” and the image of the non-magnetized dust sample will be referred to as “image of the non-magnetized dust sample”.
- a method such as spraying the dust particles from a high place may be used.
- the magnetized falling dust image and the non-magnetized dust falling image are input to an image processing apparatus and subjected to image processing.
- the contents of the image processing performed on each image are as follows. First, based on the position and brightness information of each pixel in the image, particle discrimination is performed to calculate a continuous pixel group that is discriminated as an independent particle. Next, the representative position and representative brightness of each falling dust particle are calculated. As the representative position, the center of each pixel position of the corresponding pixel group in each particle can be used. As the representative brightness, an average value of each pixel brightness of a corresponding pixel group in each particle can be used. Next, the representative lightness is compared with a predetermined lightness threshold value to classify individual particles into dark color particles and light color particles.
- the predetermined threshold value representative samples of the light-colored particle group and dark-colored particle group are prepared in advance, and image processing similar to the above is performed, and the lightness intermediate between the obtained lightness average values is obtained. Can be used as a threshold.
- all the particles in the magnetized particle image and the non-magnetized particle image using the combination of the particle brightness classification and the presence / absence of magnetization of the individual dustfall obtained in the first step Are classified into any one of magnetized dark particles, magnetized light-colored particles, non-magnetized dark-colored particles, and non-magnetized light-colored particles.
- image processing apparatus a commercially available personal computer or the like incorporating a commercially available image processing software (for example, “Image Pro Pro Plus version 5”) or the like can be used. This can be realized by using binarization, boundary discrimination, particle measurement function, etc. of the image.
- image processing software for example, “Image Pro Pro Plus version 5”
- all the particles in the magnetized particle image and the non-magnetized particle image are determined as one of the predetermined dust types based on the dust characteristics.
- Predetermined soot species are representative of the same type (iron ore, coal, coke, iron powder, blast furnace slag, converter slag, etc.) particle samples, and particle brightness discrimination is performed by the above magnetic force sorting and image processing. Then, an average dust characteristic (any of magnetized dark colored particles, magnetized light colored particles, non-magnetized dark colored particles, and non-magnetized light colored particles) is obtained. From the results of the inventor's investigation, iron ore and iron powder are classified as dark magnetic particles, so that the dark magnetic particles can be adopted as one of the predetermined dust types as “iron dust”.
- the non-magnetized dark particles can be adopted as “carbon-based dust” as one of the predetermined dust types.
- steelmaking slag and blast furnace slag are classified into magnetized bright particles and non-magnetized dark particles, respectively.
- Each of the “slag dusts” can be adopted as one of the predetermined dust types.
- the embodiment of the present invention described above can be realized by a computer executing a program.
- a computer-readable recording medium in which the program is recorded and a computer program product such as the program can also be applied as an embodiment of the present invention.
- the recording medium for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.
- the first feature is that it is possible to search for the dust generation source of the falling dust by directly measuring the falling dust at the falling dust evaluation point.
- the second feature is that, in searching for the dust source of the falling dust, the dust source search area that extends in the windward direction from the falling dust evaluation point is associated with the plume expression, thereby reducing the dust generation amount in the dust source candidate. It is a point where information can be obtained.
- equation (4) becomes the following equation (6).
- the coordinate conversion from z to Z according to the equation (5) is performed by setting tan ⁇ 1 (V s (particle fall velocity) / WS ( This corresponds to setting the central axis of the dust plume at the depression angle of the wind speed)) and defining the concentration with this central axis as the Z axis.
- the plume diffusion widths ⁇ y and ⁇ z are standard deviations of the concentration distribution in the y direction and the z direction (usually V s ⁇ WS, where the z direction can be regarded as being substantially equal to the Z direction).
- the density distribution in the y direction and the z direction can be regarded as a normal distribution.
- within the plume range means a region closer to the central axis than the plume diffusion width in the direction perpendicular to the central axis from the central axis of the plume, as shown in Expression (4).
- ⁇ y of the plume diffusion width the value of the standard deviation of the density when a Gaussian distribution is assumed as the density distribution can be used.
- the horizontal component ⁇ y of the plume diffusion width is a function of the distance L 0 from the dust generation source and the time period ⁇ t d ( ⁇ y [L 0 , ⁇ t d ]).
- the horizontal component ⁇ y of the plume diffusion width is obtained by Pasquill-Gifford described in Non-Patent Document 1 as a numerical or charted value with the time period ⁇ t d fixed (this is a reference period). It is obtained by correcting the influence of the time period ⁇ t d by an empirical formula using a thing or a thing by Briggs. How to correct the influence of the time period Delta] t d in empirical formula, as shown in Non-Patent Document 2, the horizontal component sigma y of the plume spreading width, ([Delta] t d is actually used] / [reference time Delta] t d ]) Multiply by P.
- the vertical velocity ⁇ z of the plume diffusion width is significantly larger than that during gas diffusion because the falling speed of the particles varies among the particles. Therefore, as the gas diffusion, the assumed concentration distribution similar to Gaussian distribution and the horizontal component ⁇ y plume spreading width, can not be applied to the vertical component sigma z plume spreading width.
- the target dustfall is classified by the particle size threshold value, and the dustfall amount is measured in each particle size category.
- uniformly set the upper end of the plume emitted from the source [lower limit value of the particle fall velocity in the particle size category] / [representative wind speed] Is set in the vertical plane as a gradient line determined based on the vertical plane, and the lower end of the plume is defined as a gradient line determined based on [upper limit value of particle falling speed in the particle size category] / [representative wind speed].
- the area between the upper end and the lower end of the plumes was set within the plume range. That is, the plume width vertical component ⁇ z is the vertical length of the plume range (the width in the direction perpendicular to the central axis of the plume).
- the lower limit value and the upper limit value of the particle drop speed correspond to the particle drop speeds at the minimum and maximum particle size thresholds in the particle size category, respectively.
- the distribution of the particle concentration within the plume range is not a problem, and it is only necessary to specify the plume range.
- the plume diffusion width can be specified accurately and easily by such handling. It is possible to prevent the setting of the dust source search area so that the dust source is outside the range of the dust source search area, and the dust source can be specified accurately.
- the local dust fall amount M (x) within the plume range is determined only by the dust generation amount Q P and the plume diffusion widths ⁇ y and ⁇ z .
- the plume diffusion widths ⁇ y and ⁇ z can be expressed as a function of a distance x from a specific dust generation source and weather conditions, for example, by the Pasquill-Gifford equation described in Non-Patent Document 1. Therefore, under certain dust generation conditions and certain weather conditions, the amount of dust fall M (x) at a specific dust fall evaluation point should be expressed only by the distance x from the particular dust source. Can do.
- FIG. 7 shows an example of x ′, y ′ (on the same horizontal plane (the ground surface) as the falling dust evaluation point i M ) on the entire coordinate system x ′, y ′ in the horizontal plane with the specific falling dust evaluation point i M as the origin.
- the wind direction WD is the direction of x ′.
- the plumes ⁇ (i o1 ) and ⁇ (i o2 ) are arranged so that the negative end of y ′ and the positive end of y ′ in plume ⁇ (i o2 ) pass through the origin O. Yes.
- This is the limit position where the evaluation point i M can be reached. That is, the position of the dust generation source i o1 is the limit position on the plus side of y ′, and the position of the dust generation source i o2 is the limit position on the minus side of y ′.
- i o1 when estimating the position of the dust source i o1, i o2 when dustfall in dustfall evaluation point i M is measured, in the horizontal plane, can be present in Hatsuchirigen i o1, i o2 range is a line passing through the point of origin O and dust source i o1, and the origin O and dust source i region and sandwiched between a line passing through the point o2 ⁇ (i M) (indicated by hatching This region ⁇ (i M ) is the dust source search range.
- the half width of the range of i o2 in the y ′ direction is always the plume diffusion width ⁇ y (x ′). That is, the half width of the dust generation source search range ⁇ (i M ) in the y ′ direction has the same form as the plume equation of the equations (9a) and (9b).
- dust source search area gamma (i M) in a horizontal plane, on the central shaft 11 extending from the dustfall evaluation point i M upwind direction of the representative wind direction WD, the distance from the dustfall evaluation point i M Can be set by the search area width (plume diffusion width ⁇ y (x ′)) expressed by the function of
- FIG. 8A and 8B are image diagrams illustrating an example of a method for setting the dust generation source search region ⁇ (i M ) in the vertical cross section.
- FIG. 8A is a diagram showing an example of a state in which the dust generation source search region ⁇ (i M ) in the vertical section is set in combination with the plume diffusion width ⁇ z similar to that in the horizontal section and the influence of particle fall. It is. Setting about Plume diffusion width sigma z, except replacing the horizontal direction of the plume spreading width sigma y in the vertical direction of the plume spreading width sigma z, it is the same as the setting in essentially horizontal section.
- the particle size in the collected dust sample is widely distributed, and the falling speed of individual particles contained in the same dust sample is several orders of magnitude different. For this reason, the falling dust sample should be classified by the particle size that most affects the particle fall rate.
- the number of particle size categories is set to an extremely large number, the amount of dust fall samples per particle size category becomes too small, and the error in the analysis using the dust fall samples increases. In general, the number of must be limited to a small number. This is because only a small amount of falling dust sample obtained in a short time is used for analysis of the unsteady dust generation source.
- the particle size difference within the particle size segment is usually several times, and the difference in particle drop speed still has a non-negligible effect even within the same particle size segment. Therefore, a plume ( ⁇ (i o3 )) corresponding to the largest particle and a plume ( ⁇ (i o4 )) corresponding to the smallest particle within a certain particle size category are set, and the region sandwiched between these plumes. Is set as the dust generation source search region ⁇ (i M ), the dust generation source search region ⁇ (i M ) can be specified for all particles in the particle size category.
- the particle fall speed V s here corresponds to the maximum particle size (in the case of ⁇ (i o3 )) and the minimum particle size (in the case of ⁇ (i o4 )) in the range of the particle size classification. Therefore, among windward direction point of dustfall evaluation point i M, dustfall can reach from Hatsuchirigen i o3, i o4 until dustfall evaluation point i M is to that dust in some areas It will be limited. In this way, in the dust source search method for extending the source search region ⁇ (i M ) from the falling dust evaluation point i M in the windward direction, limiting the range of the distance in the windward direction is a conventional method. This method is advantageous over the conventional method in that the dust generation source search region ⁇ (i M ) can be limited.
- the present inventors show that in dustfall, the broadening of the dust generation source search range ⁇ (i M ) due to variations in the particle fall speed within the particle size category is generally larger than the plume diffusion width. I found. Therefore, in order to simplify the analysis, as shown in FIG. 8B, in setting the vertical component of the dust generation source search range ⁇ (i M ), the plume diffusion width is ignored and the variation in the particle fall velocity V s is ignored.
- the dust source search region ⁇ (i M ) considering only the influence is set, that is, the central axes 12 and 13 of the plumes ⁇ (i o3 ) and ⁇ (i o4 ) are set in the dust source search region ⁇ (i M ). Added improvements to the outer edge.
- this invention is not limited to using the plume type
- the ground surface concentration in the equations (9a) and (9b) is based on the plume equation that leaves the ground surface reflection term. You may add suitably the term etc. which correct
- the third feature is that it is not always necessary to presuppose the dust generation source and the dust generation amount. Since there are many cases where the actual dust generation source is not known in all of its position and dust generation amount, the method proposed here is advantageous in that it can search for a dust generation source in accordance with reality.
- the fourth feature is that an unsteady dust generation source can be specified.
- the dust source search method proposed this time at each time period of the acquisition period of the measured value of the amount of falling dust or every several minutes of the acquisition period of the measured value of the amount of falling dust, Major sources of dust can be identified. Therefore, this can be grasped if it is an unsteady dust generation source that fluctuates on a time scale of several cycles or more of the acquisition period of the measurement value of the amount of dustfall.
- the number of falling dust evaluation points necessary for identifying the unsteady dust generation source may be sufficiently smaller than the number of potential dust generation sources.
- Measured value of the dustfall amount measurement means (device) by dustfall amount every time period Delta] t d is outputted.
- Time t d (i t-1) from the time t d (i t) until the time (period) is defined as the period T d (i t).
- i t is an integer that increases by 1 with the time when the measurement of dustfall started being set to 0.
- the source of the falling dust in each period T d (it) is specified, and the dust source having a time scale (that is, the dust generation duration) equal to or greater than the time period ⁇ t d is searched. The target of.
- the dust generation source search device is realized by using, for example, an information processing device (for example, a commercially available personal computer (PC)) including an arithmetic device such as a CPU, a memory, an HDD, and various interfaces.
- an information processing device for example, a commercially available personal computer (PC)
- PC personal computer
- the flowchart of FIG. 9 is translated into a computer program that can be executed using a programming language such as C language and stored in advance in an HDD or the like.
- the executable computer program stored in the HDD or the like is read and started by an arithmetic device such as a CPU, and based on a command of the executable computer program
- the calculation is realized by sequentially executing the calculation by a calculation device such as a CPU.
- the start timing of the dust generation source search process shown in FIG. 9 may be such that the executable computer program may be started manually, or may be automatically started periodically.
- dust source searching apparatus of the present embodiment at a certain time, to search for a dust source of dustfall in "period T d (i t)".
- necessary input information such as position information such as evaluation points and coordinate points, measured values such as the amount of dustfall, wind direction, and wind speed, and analysis values related to dust types are stored on a keyboard connected to the information processing device. Using a console screen or the like, it can be input manually in advance.
- the input information that has been input is stored in an HDD or the like, and is appropriately read out as the generation source search process proceeds.
- the unsteady dust source determination result and the calculation result such as the dust generation amount for the calculated specific coordinate point can be stored in the HDD or the like and displayed on the console screen or the like.
- step S101 dust source searching apparatus, a specific time period T d (i t), specific dustfall amount management point i M, and the representative wind direction WD in a specific particle size range j, the representative wind speed WS, and, the set representative dustfall amount M at a particular dustfall amount management point i M.
- the representative dustfall amount M is, for example, by using a continuous dustfall meter described in Patent Document 6, the time period Delta] t d, for example, can be measured as 10 minutes.
- the representative wind direction WD and the representative wind speed WS are, for example, a commercially available propeller type anemometer provided in the vicinity of the dustfall management point i M , and using this, a time period ⁇ t wd that is not longer (shorter) than the time period ⁇ t d. (e.g., 1 second cycle) continuously obtained measurement values obtained by averaging in the time period T d (i t).
- the spatial resolution of the wind direction measurement for example, the wind direction can be measured at intervals of 1 °.
- the vicinity of the descending dust management point i M may be a range in which the wind direction / wind speed has a high correlation with the wind direction / wind speed above the descending dust management point i M , for example, the descending dust management point i
- the horizontal distance can be within 1 km from M. In areas where the terrain is monotonous and the wind direction / velocity distribution is small, a longer horizontal distance may be set near the dustfall management point i M.
- 10 m from the ground surface which is the measurement height recommended by the Japan Meteorological Agency can be adopted as the height of the measurement point of the wind direction and the wind speed, for example.
- the assumed height of the dust source is sufficiently higher than 10 m, for example, the height between the ground surface and the height of the dust source may be set as the height of the measurement point.
- the measurement position (sample collection position) of the representative dustfall amount M can be set to, for example, a ground altitude of 1.5 m.
- the representative dust fall amount M is, for example, from the measured value m of the fall dust amount obtained as a time period ⁇ t d (for example, 10 minutes) using a continuous dustfall meter described in Patent Document 6.
- the composition ratio C with respect to the total collection rate of the target particle size classification can be obtained as m ⁇ C.
- the method of classifying the collected individual falling dust particles into particle size categories is, for example, firstly observing and measuring the collected individual falling dust particles with a microscope or the like, and then measuring the size and shape of the falling dust particles. Record. Next, the equivalent particle size of the dust particle can be calculated using the size, shape, and density of each dust particle, and the equivalent particle size can be classified using a predetermined particle size threshold. . In general, particles having the same equivalent particle diameter are considered to have the same particle fall speed Vs. Therefore, the classification of the falling dust particles using the equivalent particle diameter is substantially equivalent to the classification based on the particle fall speed Vs. It is.
- the falling dust particles are It can be classified into any of two or more equivalent particle sizes.
- the equivalent particle size is calculated by multiplying the spherical diameter of a volume equal to the volume of each falling dust particle by a correction factor determined in advance based on the shape (aspect ratio, etc.) of the falling dust particle. Can do.
- the density of the falling dust particles may be measured, or a literature value or the like may be used when the dust type can be specified in advance.
- the mass of all the falling dust particles is calculated by accumulating the amount of the dust falling particles obtained in the same manner in the whole particle size classification, and the ratio of the mass of the dust falling particles in the particle size classification and the mass of all the falling dust particles is calculated.
- the composition ratio C can be used. By doing so, the calculation error at the time of calculating the mass of the falling dust particles in the particle size category is canceled out, so that the representative dust falling amount M can be obtained with high accuracy.
- the dust generation source search device sets an orthogonal coordinate system of x, y, and z in a three-dimensional region where the search for the dust generation source can be performed, and in step S102 of FIG. 9, the dust generation evaluation point i M is set.
- a position in the horizontal plane is calculated (set) as a falling dust evaluation point vector P (i M ) that is a vector from the origin of the orthogonal coordinate system.
- step S103 the dust source search device sets a horizontal component of the dust source search region ⁇ (i M ) related to the falling dust evaluation point i M.
- the dust source search device starts from the dust fall evaluation point i M in the three-dimensional region, and in the direction of the representative wind direction WD (that is, the windward direction), the dust source search region ⁇ ( Set the linear horizontal component of the central axis of i M ).
- the dust generation source search device has the central axis as a distance from the central axis on both sides of the horizontal component of the central axis on a horizontal plane including the central axis of the dust source search region ⁇ (i M ).
- the dust generation source search region ⁇ (i M ) so as to always maintain the distance of the plume diffusion width ⁇ y that is a function of the distance between the upper point and the falling dust evaluation point i M (see Equation (1)). Set the horizontal outer edge of the.
- step S104 the dust source search device sets a vertical component of the dust source search region ⁇ (i M ) related to the falling dust evaluation point i M.
- the dust source search device is in the vertical plane of the three-dimensional region, and includes the horizontal component of the central axis of the dust source search region ⁇ (i M ).
- the dust generation source searching apparatus calculates the elevation angle ⁇ calculated using the particle fall speed V smin and the representative wind speed WS corresponding to the minimum particle size (for example, the lower limit threshold value of the particle size) of the particle size category.
- the dust source search device determines a vertical component of the central axis of the dust source search region ⁇ (i M ).
- the vertical component of the central axis of the dust generation source search region ⁇ (i M ) is a straight line starting from the dustfall evaluation point i M and extending in the vertical plane at an elevation angle of ( ⁇ max + ⁇ min ) / 2.
- the particle falling speed V s may be actually measured, or may be obtained by the following expression (10) by applying an equivalent particle diameter to the Stokes terminal speed expression.
- V s ⁇ 4gD p ( ⁇ p - ⁇ f) / 3 ⁇ f C R ⁇ 1/2 ⁇ (10)
- the dust source search device has a rectangular cross section surrounded by the two outer edge curves set in step S103 and the upper edge straight line and the lower edge straight line set in step S104.
- a three-dimensional region is set as a dust generation source search region ⁇ (i M ).
- step S1001 search area setting
- the search area setting step is expanded to a step in which a dust source search area ⁇ (i) is set for each of the plurality of management points i.
- the dust source search device estimates the dust generation amount at the specific point p in the three-dimensional region.
- the dust source search device sets a point p included in the dust source search region ⁇ (i M ) as a specific point p (i M ).
- the method for setting the specific point p (i M ) may be arbitrary.
- a point corresponding to this candidate is designated as a specific point p (i M ).
- step S107 the dust generation source search device determines a position vector Sc starting from the origin and ending at the specific point p (i M ) in the three-dimensional region.
- step S108 the dust generation source search device calculates a distance L d between the falling dust control point i M and the specific point p (i M ).
- This distance L d (i M ) is calculated as a norm of a vector connecting the end point of the position vector P (i M ) of the dustfall management point i M and the end point of the position vector Sc.
- dust source searching apparatus is a cross-sectional area of the cross section of the dust source search area gamma (i M), wherein a specific point p (i M), and dust source search area gamma (i M) to calculate a dust source search area cross-sectional area S p is the cross-sectional area of the cross section in a direction perpendicular to the central axis of.
- the dust source search area cross-sectional area S p for example, corresponding to the cross section, and the outer edge distance of the horizontal cross section of the dust source search area gamma (i M), the dust source search area gamma (i M) It can be obtained by multiplying the distance between the upper edge and the lower edge of the vertical cross section.
- the dust generation source search device calculates an estimated dust generation amount E (p, i M ) at the specific point p (i M ).
- the estimated dust generation amount E (p, i M ) at the specific point p (i M ) can be calculated by using the following equation (11), for example.
- This equation (11) corresponds to the fact that, in a general plume equation, the local concentration of dustfall is proportional to the amount of dustfall at the source and inversely proportional to the local plume cross-sectional area.
- the dust generation source search device determines the dust generation source and estimates the dust generation amount.
- the value of the estimated amount of dust E (p, i M) at a particular point p (i M) is calculated using the coordinate point vector Sc of (i x, i y, i z) and the distance L d. Further, the dust generation source is determined using this E (p, i M ).
- step S1002 dust generation amount estimation
- the dust generation amount estimation step is extended to a method using a plurality of dust generation source search regions ⁇ in various embodiments described later.
- the specific expansion method will be described in the following description of various embodiments.
- some of the three-dimensional region may implement the search for dust source, x, y, and set the z becomes orthogonal coordinate system, respectively n x on each coordinate axis, n y, n z pieces of coordinates the component is provided, will be representative of the three-dimensional space with n x ⁇ n y ⁇ n z pieces of coordinate points p (where, p is, i x th coordinate axes components, respectively, i y th, i z Represents the coordinate point that is th).
- any one of three modes of “dust generation source”, “not a dust generation source”, and “undecided” is set as a dust generation source determination mode.
- step S201 the dust source search device initializes the dust source judgment mode to “undecided” at all coordinate points p.
- step 202 dust source searching apparatus, the representative wind speed WD in the period T d (i t), representative wind speed WS, and sets the particle size range.
- These setting methods may be the same as those in the first embodiment.
- step S203 the dust generation source search device selects an unselected dustfall management point (the dustfall management point is identified by the number i M. N M ⁇ i M ⁇ 1). Then, in step S203 ⁇ 205, dust source searching apparatus, for all dustfall management point i M, by applying the process of the step S1001 (the search area setting), the representative dustfall amount M (i M ) For each.
- step S206 the dust generation source search device selects one unselected dustfall management point i M1 .
- the dust generation source search device selects one unselected dustfall management point i M2 in step S207, and selects one unselected coordinate point p in step S208.
- the dust source search device determines the dust source based on the processing at all combinations of the two falling dust evaluation points i M1 and i M2 for all coordinate points p. Do.
- an example of a method for determining a dust generation source using two different specific dust falling management points i M1 and i M2 at a specific coordinate point p will be described.
- FIG. 11 is a diagram for explaining an example of an outline of a method for searching for a dust generation source.
- dust generation source search areas corresponding to the dustfall evaluation points i M1 and i M2 are indicated as ⁇ (i M1 ) and ⁇ (i M2 ), respectively.
- ⁇ (i M1 ) and ⁇ (i M2 ) are indicated as the target of the dust generation source determination.
- step S209 dust source searching apparatus, the position vector Sc of the coordinate point p (i x, i y, z) defining a.
- Position vector Sc is a starting point the origin of the coordinate axes, the coordinate axes components i x th respectively, i y th, i z th coordinate axes of the split point and become point (i.e., the coordinate points p) set to the end point Is done.
- the dust source search device is a common area on the space of the dust source search ranges ⁇ (i M1 ) and ⁇ (i M2 ) respectively corresponding to the dustfall management points i M1 and i M2. 11 determines whether the coordinate point p exists. As a result of the determination, if the coordinate point p exists in the common area 11 and the dust source determination mode at the coordinate point p is not “not a dust source”, the process proceeds to step S211. On the other hand, when the coordinate point p does not exist in the common area 11 or when the dust generation source determination mode at the coordinate point p is “not a dust generation source”, the process proceeds to steps S215 and S207. The source search device changes the coordinate point p, and again determines whether the coordinate point p exists within the dust generation source search range.
- step S211 the dust generation source search apparatus determines the estimated dust generation amounts E (p, i M1 ) and E (p, i M2 ) at the coordinate point p corresponding to the dustfall management points i M1 and i M2 , respectively. Is calculated by applying the process of step S1002 (estimated dust generation).
- the dust generation source search device calculates a ratio R between the estimated dust generation amount E (p, i M1 ) and E (p, i M2 ).
- the empirical term B 1 introduced when calculating E (p, i M ) is canceled out, so that the accuracy can be further improved.
- the ratio R may be E (p, i M1 ) / E (p, i M2 ) or E (p, i M2 ) / E (p, i M1 ).
- the dust source search device determines whether the coordinate point p is a dust source.
- the dust generation source search device is configured so that the time scale of the coordinate point p is equal to or greater than the time period ⁇ t d when the ratio R is within the range of the given upper and lower thresholds R max and R min. Is determined to be a “dust generation source”. On the other hand, if R is outside the range of the upper and lower thresholds R max and R min , the coordinate point p is determined as “not a dust generation source”.
- the dustfall evaluation point may be reached during this period T d (i t) there are a plurality of dustfall amount observed in these dustfall evaluation point includes the dust source, these According to a function of the distance between each dustfall evaluation point (ie, plume equation), they should show a constant ratio to each other. Therefore, since the coordinate point p satisfying this condition is highly likely to be a main dust source, the dust source determination is “dust source”.
- the process proceeds to step S214, and the dust source search device is determined to be “dust source”.
- the dust source search device is determined to be “dust source”. for the coordinate points p, calculates a specific estimated dust quantity E (p, i M) to the coordinate point p by using the estimated amount of dust generated E (p, i M1) and E (p, i M2).
- E (p, i M ) calculates a specific estimated dust quantity E (p, i M) to the coordinate point p by using the estimated amount of dust generated E (p, i M1) and E (p, i M2).
- E (p, i M ) an average value of estimated dust generation amounts E (p, i M1 ) and E (p, i M2 ) can be used.
- the determination of the dust generation source at all coordinate points p is performed for all combinations between the two falling dust control points i M1 and i M2 .
- the initial value “Undetermined” remains as the dust generation source determination mode.
- the amount of generation at the source is estimated by introducing the plume concept into the source search region ⁇ (i M ) that extends in the windward direction from the dustfall management point i M.
- This can be used to make a simple determination that the dust source exists in the windward direction when the measured value of the amount of dustfall is large, or only the fact that the dust source search lines intersect is used. It is possible to realize advanced dust source determination that cannot be achieved by dust source determination.
- the n t number is a natural number of 2 or more, is defined as a period successive T d (i t) period of time comprised from T g (k).
- T d (i t) period of time comprised from T g (k).
- the time of the start point of the period T g (k) and t g (k-1), a i t at this time is 0.
- the time of the end point of the period T g (k) and t g (k), the i t at this time is n t.
- k is an integer that increases by 1 with the dustfall measurement start time as 0.
- Target dust sources the present embodiment uses the same measurement values as those in the fifth embodiment, and aggregates the measured values for each time period ⁇ t g and searches for the dust source, thereby performing coordinate determination of the dust source. This is a method of substantially expanding the number of
- step S301 the dust source search device initializes the dust source judgment mode to “undecided” at all coordinate points.
- step S302 the dust generation source search device sets the particle size classification.
- step S303 dust source searching apparatus selects one dustfall management point i M unselected.
- step S304 dust source searching apparatus includes, for particular dustfall management point i M, maximum dustfall amount in the period T g every period included in (k) T d (i t ) A time t d (i tmax ) indicating the measured value m is obtained.
- i t is the order of the period T d (i t) in a period T g (k), is 1 ⁇ i t ⁇ n t.
- i tmax is the order of the period T g time t d (i tmax) indicating the measurement value m of the maximum dustfall amount of all the period included in the (k) T d (i t ) and becomes i t is there.
- dust source searching apparatus determines in step S305, increments the i t, in step S306, i t is whether exceeds its maximum value n t. If the result of this determination is that i t has not exceeded the maximum value n t, the process returns to step S304. Then, for all i t, seek period T g every period included in (k) T d time showing the measurements m maximum dustfall amount in (i t) t d (i tmax).
- the dust generation source search device obtains the representative dust fall amount M (i M ), the representative wind direction WD (i M ), and the representative wind speed WS (i M ) related to the dust fall management point i M.
- the representative dust fall amount M (i M ) the dust fall in the period T d (it max ) in which the maximum dust fall amount is measured.
- the quantity measurement m can be used.
- the representative wind direction WD (i M ) and the representative wind speed S (i M ) the average value of the measured values of the wind direction during the period T d (it max ), the maximum amount of dust fall, An average value of measured values can be used.
- the following method can also be used as the second method for setting the representative dust fall amount M (i M ), the representative wind direction WD (i M ), and the representative wind speed WS (i M ).
- the upper and lower thresholds are set for the wind direction and the wind speed, and the measured values of the wind direction and the wind speed are classified into the wind direction and the wind speed classification, and the period T d (i t ) in all the periods T g (k).
- the average value of the measured value m of the dust fall amount in each wind direction and wind speed category is obtained.
- the maximum value of the measurement value m of the amount of dust fall between each wind direction and wind speed category is the representative dust fall amount M (i M ), and it corresponds to the wind direction and wind speed category to which the maximum value of the measurement value m of the dust fall amount belongs.
- the wind direction and the wind speed be the representative wind direction WD (i M ) and the representative wind speed WS (i M ), respectively.
- the average value of the upper threshold value and the lower threshold value corresponding to the wind direction / wind speed classification can be used as the wind direction / wind speed calculation method corresponding to the wind direction / wind speed classification.
- the first method corresponds to a special case of the second method in which the wind direction / wind speed classification is extremely subdivided in the second method, and the measured values classified into each wind direction / wind speed classification are substantially the same. 1 set or less (measured values are not classified in most wind directions and wind speed categories).
- Time periods as the T g (k) if the first method, for example (when the time period Delta] t d is 10 minutes, 1 hour) time 6 period of the periodic Delta] t d can be employed.
- a time period ⁇ t d of 100 cycles or more is set as the period T g (k). It can also be adopted.
- the wind direction threshold value for example, division by 1 to 22.5 ° can be used. Further, a division of 1 to 5 m / s can be used as the wind speed threshold.
- step S308 dust source searching apparatus, to the dustfall management point i M, by applying the process of the step S1001 (the search area setting), the representative dustfall amount M of (i M), respectively Set. Then, in step S309, the dust source searching apparatus determines whether to select all dustfall management point i M, if not select all of dustfall management point i M, the step S303 Return to. In this way, it is possible to make settings for all the falling dust control points i M.
- Subsequent steps S310 to S321 are the same as steps S206 to S217 described in the fifth embodiment. In this way, in this embodiment, it is possible to determine the dust generation source and the estimated dust generation amount E (p, i M ).
- the representative wind direction WD and the representative wind speed WS are generally different for each falling dust management point i M. Therefore, dust source search area of each dustfall evaluation point i M ⁇ (i M) is likely to cross each other in the vicinity of the dustfall evaluation point i M. Therefore, this embodiment is advantageous for dust generation source determination in the vicinity of the falling dust evaluation point i M.
- FIG. 13 is a diagram schematically illustrating a source search method in which the method of the present embodiment is applied to the same target system as illustrated in FIG. 14 schematically illustrating the source search method in the conventional method. It is. The advantages of this embodiment will be described with reference to FIG.
- the intersections 6, 7, and 8 of the source search lines 2, 3, and 4 are regarded as dust generation sources in FIG.
- the conventional technology lacks information on the amount of generation on the source search lines 2, 3, and 4, whether or not these individual intersections 6, 7, and 8 are appropriate as dust generation sources is more than this. You cannot get information.
- intersection point 6 may actually be a major source, but apparently occurs at this intersection point 6 due to the influence of other major dust sources on the falling dust control points i M1 and i M2 .
- Source search lines 2, 3 and 4 may have just intersected (for example, the main source for the descending dust control point i M1 is the intersection 7 and the main source of dust for the descending dust control point i M2 is It may be an unknown source located at the intersection 8 or closer to the falling dust control point i M2 than the facility c).
- FIG. 13 it can be examined whether it is appropriate as a dust source in the intersection area
- the estimated dust generation amount E (p 1 , p 1 , for the falling dust evaluation points i M1 and i M2 of the coordinate point p 1 respectively.
- the dust source can be determined quantitatively.
- the dust generation source search region ⁇ (i M ) is a three-dimensional space using the analysis result of the particle size of the falling dust sample obtained at the falling dust evaluation point i M. Expanded on top. For this reason, in the conventional method, even if the dust source search regions ⁇ (i M ) seem to intersect each other at first glance in the plan view of FIG. 13, the source search region ⁇ (i In many cases, no common area exists between M ).
- the radioactive non-stationary dust generation source can be identified separately from other non-radiation dust generation sources.
- a method for measuring the dust falling radiation for example, methods described in Patent Documents 7 to 9 can be used.
- the predetermined radiation dose threshold value for example, 1 millibecquerel can be used.
- the classification of falling dust is not limited to radioactive substances, but the falling dust sample collected at the evaluation point is classified by dust type, and whether any of the classified dust types is a source of dust. It may be determined.
- the classification of the dust species a known method such as classification based on the analysis result of the physical properties of the individual falling dust species can be used.
- the component composition ratio of each falling dust sample may be obtained quantitatively using EPMA, which is an electron microscope, and classified for each dust type based on this component structure.
- the processing performed by the dust source search device is realized by the computer executing the program.
- a computer-readable recording medium in which the program is recorded and a computer program product such as the program can also be applied as an embodiment of the present invention.
- the recording medium for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.
- the present invention can be widely applied to a method for searching for a dust generation source of falling dust in which the amount of dust generation (the generation speed of falling dust in the dust generation source) fluctuates non-steadily in a nuclear power plant or the like.
- the source can be searched efficiently and accurately.
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Abstract
Description
本願は、2011年8月16日に、日本に出願された特願2011-178038号、2011年11月28日に、日本に出願された特願2011-258757号、2012年3月14日に、日本に出願された特願2012-057303号、および2012年6月7日に、日本に出願された特願2012-129861号に基づき優先権を主張し、これらの内容をここに援用する。
×{exp[-(He-z)2/2σz 2]
+exp[-(He+z)2/2σz 2]} ・・・(1)
x,y,z:評価地点の3次元直交座標(ガス発生源を原点とする)[m]
x:水平面上で、プルーム中心軸がのびる方向に対応する座標値
y:水平面上で、プルーム中心軸がのびる方向に垂直な方向(以下の説明では、この方向を必要に応じて「水平方向」と称する)の座標値
z:鉛直方向(以下の説明では、この方向を必要に応じて「鉛直方向」と称する)の座標値
C:評価地点(x,y,z)でのガス濃度[kg/m3、又は、m3/m3]
QP:ガス発生量[kg/s、又は、m3/s]
WS:風速[m/s]
He:ガス発生源の地表面からの高さ[m]
σy、σz:ガスプルーム拡散幅[m](ガス流れに垂直な方向のガス濃度分布の標準偏差であり、σyは水平方向のガスプルーム拡散幅、σzは鉛直方向のガスプルーム拡散幅である)。
特許文献5では、ガスプルーム拡散幅σy、σzを、ガス流れに対して垂直方向のガス濃度分布の標準偏差と定義している。
×{exp[-(He-z-Vsx/WS)2/2σz 2]
+α・exp[-(He+z-Vsx/WS)2/2σz 2]}・・・(2)
Vd:沈着速度[m/s]
Vs:落下速度[m/s](SPMの場合。ガスの場合は0)
C(x)=B(QP/2πσyσzWS) (プルーム範囲内) ・・・(A)
C(x)=0 (プルーム範囲外) ・・・(B)
C(x)=B(QP/2πσyσzWS) (プルーム範囲内) ・・・(A)
C(x)=0 (プルーム範囲外) ・・・(B)
ここで、(A)式および(B)式の単位は、全てSI単位であり、σzは、鉛直面内において、発生源を起点とするプルームの上端を[当該粒径区分における粒子落下速度下限値]/[代表風速]に基づいて定められる勾配線とするとともに、当該プルームの下端を[当該粒径区分における粒子落下速度上限値]/[代表風速]に基づいて定められる勾配線として定義されるプルーム範囲の、前記プルームの中心軸に垂直な方向の幅とする。
まず、本発明の実施形態の特徴について説明する。
×exp[-(He-z-Vsx/WS)2/2σz 2]・・・(4)
×exp[-y2/2σy 2]exp[-Z2/2σz 2]・・・(6)
C(x)=0 (プルーム範囲外) ・・・(7b)
B:比例定数
本手法においては、式(7a)は、相対値のみを問題とするので、比例定数Bには任意の値(例えば、1)を与えてよい。
M(x)=0 (プルーム範囲外) ・・・(9b)
まず、本発明の第1の実施形態について説明する。
g: 重力加速度[m/s2]
Dp: 粒子径[m]
ρP,ρf: 粒子、流体の密度[kg/m3]
CR: 抵抗係数[-](粒子形状に応じて各種の数表が開示されている)
E2=B1Sp2M(iN,it) ・・・(11b)
次に、本発明の第2の実施形態を説明する。
次に、本発明の第3の実施形態を説明する。
×exp[-(He-z-Vsx/WS)2/2σz 2] ・・・(4)
×exp[-y2/2σy 2]exp[-Z2/2σz 2] ・・・(6)
C(x)=0 (プルーム範囲外) ・・・(7b)
B:比例定数
プルーム範囲内: σy≧y≧-σy かつ σz≧Z≧-σz ・・・(8)
M(x)=0 (プルーム範囲外) ・・・(9b)
以上の様な、降下煤塵量のプルーム式を変形した発塵源探索範囲γ(iM)の単純、かつ、定量的な表現は、従来のガスやSPMを前提としたプルーム式では実現しえなかったものであり、本発明者らが降下煤塵の粒子落下速度Vsが比較的大きいことに着目した上で行った一連の洞察によって初めて可能になったものである。
後述の各種実施形態に共通する本発明の考え方を、図9のフローチャートを参照しながら説明する。説明を簡略化するために、図9のフローチャートでは、特定の時刻において1つの発塵源探索領域を設定し、期間Td(it)における降下煤塵の発生源を特定する際の本実施形態の発塵源探索装置の処理の考え方の一例を説明する。図9のフローチャートに示す発塵源探索方法は、後述の各種実施形態の説明において、発塵源を複数設定する、期間Tg(k)内の期間Td(it)に適用する等の拡張を加えられたうえで、具体的に記述される。
g: 重力加速度 [m/s2]
Dp: 等価粒子径 [m]
ρp,ρf: 粒子、流体の密度 [kg/m3]
CR: 抵抗係数 [-]
後述の各種実施形態において、探索領域設定工程は、複数の管理地点iに対してぞれぞれ発塵源探索領域γ(i)が設定される工程に拡張される。
次に、本発明の第4の実施形態について説明する。
次に、本発明の第5の実施形態について説明する。
次に、本発明の第6の実施形態について説明する。上述した非定常発塵源の探索を、放射性の非定常発塵源の探索に適用することができる。
2、3、4、5 発生源探索線
6、7、8 発生源探索線の交点
9 降下煤塵プルームの中心軸
10a、10b、10c、10d プルームの中心軸
11 発塵源探索領域の中心軸
12 粒径区分内最大粒子径における降下煤塵プルームの中心軸
13 粒径区分内最小粒子径における降下煤塵プルームの中心軸
41、51 発塵源探索領域間の共通領域
a、b、c、d、e 予め想定される発生源
i1、i2、i3、iM、iN、iM1、iM2、iM3 降下煤塵評価(管理)地点
io1、io2、io3、io4 発塵源
p、p1、p2、p3、p4 座標点
L0 発塵源を配置するx'
O 原点
WD 風向
α(io1)、α(io2)、α(io3)、α(io4) プルーム
σy(L0)、σz(x') プルームの拡散幅
γ(iM)、γ(iM,it)、γ(iN,it)、γ(iM1)、γ(iM2)、γ(iM3)、γ(i1,itmax)、γ(i2,itmax)、γ(i3,itmax)、γ(i3,it2) 発塵源探索範囲
θ プルームの中心軸の傾斜角度
θmax 粒径区分内最大粒子径におけるプルームの中心軸の傾斜角度
θmin 粒径区分内最小粒子径におけるプルームの中心軸の傾斜角度
Claims (22)
- 時間周期Δtdごとのit番目の時刻を時刻td(it)として、互いに異なる2つ以上の降下煤塵評価地点iにおける、時刻td(it-1)から時刻td(it)までの期間である期間Td(it)に降下煤塵を捕集し、単位時間あたりの降下煤塵量Mの測定値を得る煤塵量設定工程と;
前記降下煤塵評価地点iの近傍において、前記期間Td(it)に前記時間周期Δtdよりも短い時間周期Δtwintで連続的に風向を測定し、前記期間Td(it)における代表風向WD(it)を導出する代表風向導出工程と;
前記降下煤塵評価地点iの近傍において、前記期間Td(it)に前記時間周期Δtwintで連続的に風速を測定し、前記期間Td(it)における代表風速WS(it)を導出する代表風速導出工程と;
前記期間Td(it)に捕集された降下煤塵粒子の落下速度の計測値または降下煤塵粒子の粒径分布から、前記期間Td(it)における個々の降下煤塵粒子の粒子落下速度Vsを導出する粒子落下速度導出工程と;
前記期間Td(it)における降下煤塵探索領域γ(i,it)として、第1の降下煤塵評価地点iMを始点とし、前記代表風向WD(it)の風上方向にのびる第1の中心軸を有すると共に、前記第1の中心軸の周囲に第1の降下煤塵発生源探索領域幅を設けて前記第1の中心軸から垂直方向に前記第1の降下煤塵発生源探索領域幅までの距離の範囲を領域とする第1の降下煤塵発生源探索領域γ(iM,it)と、前記第1の降下煤塵評価地点iMとは異なる第2の降下煤塵評価地点iNを始点とし、前記代表風向WD(it)の風上方向にのびる第2の中心軸を有すると共に、前記第2の中心軸の周囲に第2の降下煤塵発生源探索領域幅を設けて前記第2の中心軸から垂直方向に前記第2の降下煤塵発生源探索領域幅までの距離の範囲を領域とする第2の降下煤塵発生源探索領域γ(iN,it)と、を設定する降下煤塵発生源探索領域設定工程と;
前記第1の降下煤塵評価地点iMにおいて、1つまたは2つ以上の連続する前記期間Td(it)を含む期間Tg(k)内で測定した前記降下煤塵量Mの測定値が最大となる時刻td(it)における最大降下煤塵量Mmax(iM)と、当該時刻td(it)における前記第1の降下煤塵評価地点iMにおけるitであるimax(iM)と、当該時刻td(it)における前記代表風向WDmaxと前記代表風速WSmaxと、を導出する最大降下煤塵情報導出工程と;
前記第1の降下煤塵発生源探索領域γ(iM,it)としてγ(iM,imax(iM))を、前記第2の降下煤塵発生源探索領域γ(iN,it)として前記期間Tg(k)内の任意の期間Td(it)に対応するitを用い、前記第1の降下煤塵発生源探索領域γ(iM,imax(iM))及び前記第2の降下煤塵発生源探索領域γ(iN,it)の双方の中に含まれる座標点pと、前記第1の降下煤塵評価地点iMとの間の第1の距離Ld(iM)、および前記座標点pと前記第2の降下煤塵評価地点iNとの間の第2の距離Ld(iN)を算出する距離算出工程と;
前記座標点pを含む前記第1の降下煤塵発生源探索領域γ(iM,imax)の前記第1の中心軸の垂直面における前記第1の降下煤塵発生源探索領域の断面積である第1の発塵源探索領域中心軸垂直断面積Sp1を、前記第1の降下煤塵発生源探索領域幅を用いて算出し、前記座標点pを含む前記第2の降下煤塵発生源探索領域γ(iN,it)の前記第2の中心軸の垂直面における前記第2の降下煤塵発生源探索領域の断面積である第2の発塵源探索領域中心軸垂直断面積Sp2を、前記第2の降下煤塵発生源探索領域幅を用いて算出する断面積算出工程と;
前記第1の発塵源探索領域中心軸垂直断面積Sp1に比例する第1の仮定発塵量E1と、前記第2の発塵源探索領域中心軸垂直断面積Sp2に比例する第2の仮定発塵量E2とを算出する発塵量算出工程と;
前記座標点pを含む複数の降下煤塵発生源探索領域のある組み合わせに対して、前記発塵量算出工程において算出された、前記第1の仮定発塵量E1と前記第2の仮定発塵量E2の比が所定の上下限閾値の範囲内であれば、前記座標点pを、前記期間Tg(k)における前記時間周期Δtg以上の時間スケールを有する主要な非定常発塵源であると判断し、前記発塵量算出工程において算出された、前記第1の仮定発塵量E1と前記第2の仮定発塵量E2の比が前記所定の上下限閾値の範囲外であれば、前記座標点pを、前記期間Tg(k)期間における前記時間周期Δtg以上の時間スケールを有する主要な非定常発塵源ではないと判断すると共に、前記座標点pが前記第1の降下煤塵発生源探索領域と前記第2の降下煤塵発生源探索領域のいずれにも含まれない場合には前記座標点pでの降下煤塵の非定常発塵源の判断を行わない、発塵源判定工程と;
を含み、
プルーム式において、前記第1の降下煤塵発生源探索領域中心軸をプルーム中心軸として、前記プルーム中心軸上の前記第1の距離におけるプルーム拡散幅を算出し、算出された前記プルーム拡散幅を、前記第1の降下煤塵発生源探索領域幅として用い、前記第2の降下煤塵発生源探索領域中心軸をプルーム中心軸として、前記プルーム中心軸上の前記第2の距離におけるプルーム拡散幅を算出し、算出された前記プルーム拡散幅を、前記第2の降下煤塵発生源探索領域幅として用いることを特徴とする、降下煤塵の非定常発塵源位置の探索方法。 - 前記期間Td(it)は、連続する2つ以上の前記時刻td(it)を含む時間周期Δtgごとの時刻であってk番目の時刻をtg(k)とした場合の、時刻tg(k-1)から時刻tg(k)までの評価期間である前記期間Tg(k)に含まれる任意の期間であることを特徴とする、請求項1に記載の降下煤塵の非定常発塵源位置の探索方法。
- 前記第1の降下煤塵発生源探索領域γ(iM,imax)を、前記期間Tg(k)における前記第1の降下煤塵評価地点iMに関する非定常降下煤塵探索領域として設定し、前記第2の降下煤塵発生源探索領域γ(iN,it)を、前記期間Tg(k)の任意の時刻td(it)における前記第2の降下煤塵評価地点iNに関する非定常降下煤塵探索領域として設定することを特徴とする、請求項2に記載の降下煤塵の非定常発塵源位置の探索方法。
- 前記代表風向導出工程において、前記代表風向WD(it)は、前記期間Td(it)における前記風向の測定値の平均値として導出されることを特徴とする、請求項1に記載の降下煤塵の非定常発塵源位置の探索方法。
- 前記代表風速導出工程において、前記代表風速WS(it)は、前記期間Td(it)における前記風速の測定値の平均値として導出されることを特徴とする、請求項1に記載の降下煤塵の非定常発塵源位置の探索方法。
- 前記粒子落下速度導出工程において、前記粒子落下速度Vsは、前記期間Td(it)における前記降下煤塵の前記落下速度の測定値の平均値として導出されることを特徴とする、請求項1に記載の降下煤塵の非定常発塵源位置の探索方法。
- 前記降下煤塵発生源探索領域中心軸は、前記風向の風上方向を水平成分として有すると共に、前記降下煤塵の前記粒子落下速度Vsを前記代表風速WSで除した値Vs/WSを鉛直勾配として有し;
前記プルーム式において前記降下煤塵発生源探索領域中心軸を前記プルーム中心軸とし、前記プルーム中心軸上の前記第1または第2の距離における水平方向のプルーム拡散幅σyを前記降下煤塵発生源探索領域幅の水平成分として用い、前記プルーム中心軸上の前記第1または第2の距離における鉛直方向のプルーム拡散幅σzを前記降下煤塵発生源探索領域幅の鉛直成分としてそれぞれ用いる;
ことを特徴とする請求項1に記載の降下煤塵の非定常発塵源位置の探索方法。 - 前記プルーム拡散幅σy及びσzと、前記プルーム中心軸上の発生源からの距離xと、発塵量QPと、前記代表風速WSと、定数Bと、前記プルーム拡散幅σy及びσzを用いて定義されるプルーム範囲と、を用いて、前記プルーム中心軸上の発生源からの距離xでの煤塵濃度C(x)を表現する以下の式(A)及び(B)を、前記プルーム式として用いることを特徴とする、請求項1に記載の降下煤塵の非定常発塵源位置の探索方法。
C(x)=B(QP/2πσyσzWS) (プルーム範囲内) ・・・(A)
C(x)=0 (プルーム範囲外) ・・・(B) - 前記プルーム拡散幅σy及びσzの内、より長い方の2倍を長軸、短い方の2倍を短軸とした楕円を前記プルーム中心軸に垂直な方向のプルームの断面形状とし、前記楕円の内側をプルーム範囲内とすることを特徴とする、請求項8に記載の降下煤塵の非定常発塵源位置の探索方法。
- 前記プルーム拡散幅σy及びσzと、前記プルーム中心軸上の発生源からの距離xと、発塵量QPと、前記代表速度WSと、定数Bと、前記プルーム拡散幅σy及びσzを用いて定義されるプルーム範囲と、を用いて、前記プルーム中心軸上の発生源からの距離xでの煤塵濃度C(x)を表現する以下の式(A)及び(B)を、前記プルーム式として用いることを特徴とする、請求項7に記載の降下煤塵の非定常発塵源位置の探索方法。
C(x)=B(QP/2πσyσzWS) (プルーム範囲内) ・・・(A)
C(x)=0 (プルーム範囲外) ・・・(B) - 前記プルーム拡散幅σy及びσzの内、より長い方の2倍を長軸、短い方の2倍を短軸とした楕円を前記プルーム中心軸に垂直な方向のプルームの断面形状とし、前記楕円の内側をプルーム範囲内とすることを特徴とする、請求項10に記載の降下煤塵の非定常発塵源位置の探索方法。
- 前記期間Td(it)内に前記降下煤塵評価地点iで捕集された降下煤塵試料の放射線量を測定し、測定した前記放射線量の強度に基づいて前記降下煤塵試料を煤塵種ごとに分類する煤塵種分類工程を更に含み;
前記捕集された降下煤塵試料の内、前記煤塵種分類工程で分類されたいずれかの煤塵種に対応する部分の降下煤塵の質量を前記降下煤塵量Mとする;
ことを特徴とする、請求項1乃至11のいずれか1項に記載の降下煤塵の非定常発塵源位置の探索方法。 - 前記期間Td(it)内に前記降下煤塵評価地点iで捕集された降下煤塵試料の煤塵種を分類する煤塵種分類工程と;
前記捕集された降下煤塵試料のうち、前記煤塵種分類工程で分類されたいずれかの煤塵種に対して、前記降下煤塵評価地点iが発塵源か否かを判定する発塵源判定工程と;
を更に含むことを特徴とする、請求項1乃至11のいずれか1項に記載の降下煤塵の非定常発塵源位置の探索方法。 - 前記個々の降下煤塵粒子について、当該降下煤塵粒子に対応する前記粒子落下速度Vsを、所与のしきい値である粒子落下速度上限値Vsmaxおよび粒子落下速度下限値Vsminと比較することによって、2つ以上設定される等価粒径区分のいずれかに分類するとともに、任意の前記等価粒径区分jに分類された降下煤塵の積算量を用いて当該等価粒径区分に対する降下煤塵量mjを算出する工程と;
任意の降下煤塵評価地点iAおよび任意の等価粒径区分jについて、前記期間Td(it)における前記任意の等価粒径区分jの降下煤塵の非定常発塵源探索領域をγとし、当該降下煤塵評価地点iAを始点として、時刻td(it)における前記代表風向WDの風上方向に、前記非定常発塵源探索領域γの直線状の中心軸の水平成分を設定する工程と;
プルーム式における発塵源からの距離L0と前記時間周期Δtdとの関数である水平プルーム拡散幅σy[L0、Δtd]と、前記非定常発塵源探索領域γの中心軸上での前記始点からの距離Ldとを用いて、非定常発塵源探索領域γの水平成分として、前記非定常降下煤塵探索領域γの中心軸に直交するように、当該中心軸の両側の水平方向に、当該中心軸からプルーム拡散幅σy[Ld、Δtd]までの領域を、前記非定常発塵源探索領域γの水平成分として設定する工程と;
前記始点から、(当該等価粒径区分jにおける粒子落下速度下限値)/(前記代表風速WD)に基づく角度を勾配として、前記代表風向WDの風上方向に向けて上昇する、前記非定常発塵源探索領域の下限線と、前記始点から、(当該等価粒径区分における粒子落下速度上限値)/(前記代表風速WS)に基づく角度を勾配として、前記代表風向の風上方向に向けて上昇する、前記非定常発塵源探索領域上限線との間にはさまれた領域を、前記非定常発塵源探索領域γの鉛直成分として設定する工程と;
前記非定常発塵源探索領域γ内の任意の点qにおいて、前記降下煤塵評価地点iAにおける前記等価粒径区分jについての降下煤塵量mkと、前記非定常発塵源探索領域γの断面の断面積であって、前記点qを通り前記非定常発塵源探索領域γの中心軸に垂直な方向の断面の断面積である探索領域断面積Spと、に比例する推定発塵量E(q,iA)を算出する工程と;
前記推定発塵量E(p,iA)に基づいて発塵源を特定する工程と;
を更に含むことを特徴とする、請求項1に記載の降下煤塵の非定常発塵源の探索方法。 - 前記期間Td(it)における降下煤塵の非定常発塵源の探索方法であって、
前記代表風向WD、代表風速WSは、それぞれ、前記期間Td(it)における風向、風速の測定値の平均値であり、
任意の前記降下煤塵評価地点iAにおける前記代表降下煤塵量M(iA)は、前記期間Td(it)における当該降下煤塵評価地点iAでの降下煤塵量の測定値mから得られるものであり、
特定の前記等価粒径区分jにおいて、互いに異なる特定の前記降下煤塵評価地点iA1、iA2について、前記期間Td(it)における降下煤塵の非定常発塵源探索領域γ(iA1)、γ(iA2)をそれぞれ設定する工程と;
前記非定常発塵源探索領域γ(iA1)、γ(iA2)の、空間上で共通する共通領域内で指定される前記点qにおいて算出される前記推定発塵量E(q,iA1)、E(q,iA2)の比が所定の上下限値の範囲内である場合には、前記点qを前記特定の等価粒径区分jに関する発塵源と判定し、これ以外の場合には、前記点qを前記特定の等価粒径区分に関する発塵源ではないと判定するとともに、前記点qにおける推定発塵量E(q,iA)を、前記推定発塵量E(q,iA1)、E(q,iA2)を用いて算出する工程と;
を更に含むことを特徴とする、請求項14に記載の降下煤塵の非定常発塵源の探索方法。 - 連続する2つ以上の前記時刻td(it)を含む時間周期Δtgごとの、k番目の時刻tg(k)を設けて、時刻tg(k-1)から時刻tg(k)の評価期間である期間Tg(k)を設定する工程と;
2つ以上の前記降下煤塵評価地点を設け、特定の互いに異なる2つの前記非定常降下煤塵評価地点iA1,iA2について、前記降下煤塵の非定常発塵源探索領域γ(iA1)、γ(iA2)をそれぞれ設定する工程と;
前記非定常発塵源探索領域γ(iA1)、γ(iA2)の、空間上で共通する共通領域内で指定される前記点qにおいて算出される前記推定発塵量E(q,iA1)、E(q,iA2)の比が所定の上下限値の範囲内である場合には、前記点qを前記特定の等価粒径区分に関する発塵源と判定し、これ以外の場合には、前記点qを前記特定の等価粒径区分に関する発塵源ではないと判定するとともに、前記点qにおける推定発塵量E(q,iA)を、前記推定発塵量E(q,iA1)、E(q,iA2)を用いて算出する工程と;
を更に含むことを特徴とする、請求項14に記載の降下煤塵の非定常発塵源の探索方法。 - 前記期間Td(it)における風向測定値、風速測定値を、所与のしきい値を用いてそれぞれ風向区分、風速区分に分類するとともに、各風向区分、各風速区分を代表する、区分風向WDc、区分風速WScを算出する工程と;
任意の降下煤塵評価地点iAにおいて、前記期間Tg(k)における最大の降下煤塵量mを測定した期間Td(it)に対応する前記降下煤塵量の測定値、前記区分風向WDc、前記区分風速WScを、当該期間Tg(k)および当該降下煤塵評価地点iAにおける前記代表降下煤塵量M(iA)、前記代表風向WD(iA)、前記代表風速WS(iA)としてそれぞれ設定する工程と;
を更に含むことを特徴とする、請求項16に記載の降下煤塵の非定常発塵源の探索方法。 - 前記期間Td(it)内に前記降下煤塵評価地点iで捕集された降下煤塵試料の放射線量を測定し、測定した前記放射線量の強度に基づいて前記降下煤塵試料を煤塵種ごとに分類する煤塵種分類工程と;
分類した前記煤塵種ごとに前記降下煤塵評価地点iが発塵源か否かを判定する発塵源判定工程と;
を更に含むことを特徴とする、請求項14乃至17のいずれか1項に記載の降下煤塵の非定常発塵源位置の探索方法。 - 前記プルーム拡散幅σyおよびσzと、プルーム中心軸上の発生源からの距離xと、降下煤塵発生量QPと、前記代表風速WSと、定数Bと、前記プルーム拡散幅σyおよびσzを用いて定義されるプルーム範囲と、を用いて、プルーム中心軸上の発生源からの距離xでの煤塵濃度C(x)を表現する以下の式(A)及び(B)を、前記プルーム式として用いることを特徴とする、請求項18に記載の降下煤塵の非定常発塵源の探索方法。
C(x)=B(QP/2πσyσzWS) (プルーム範囲内) ・・・(A)
C(x)=0 (プルーム範囲外) ・・・(B)
ここで、(A)式および(B)式の単位は、全てSI単位であり、σzは、鉛直面内において、発生源を起点とするプルームの上端を[当該粒径区分における粒子落下速度下限値]/[代表風速]に基づいて定められる勾配線とするとともに、当該プルームの下端を[当該粒径区分における粒子落下速度上限値]/[代表風速]に基づいて定められる勾配線として定義されるプルーム範囲の、前記プルームの中心軸に垂直な方向の幅とする。 - 前記プルーム拡散幅σyおよびσzと、プルーム中心軸上の発生源からの距離xと、降下煤塵発生量QPと、前記代表風速WSと、定数Bと、前記プルーム拡散幅σyおよびσzを用いて定義されるプルーム範囲と、を用いて、プルーム中心軸上の発生源からの距離xでの煤塵濃度C(x)を表現する以下の式(A)及び(B)を、前記プルーム式として用いることを特徴とする、請求項14~17のいずれか1項に記載の降下煤塵の非定常発塵源の探索方法。
C(x)=B(QP/2πσyσzWS) (プルーム範囲内) ・・・(A)
C(x)=0 (プルーム範囲外) ・・・(B)
ここで、(A)式および(B)式の単位は、全てSI単位であり、σzは、鉛直面内において、発生源を起点とするプルームの上端を[当該粒径区分における粒子落下速度下限値]/[代表風速]に基づいて定められる勾配線とするとともに、当該プルームの下端を[当該粒径区分における粒子落下速度上限値]/[代表風速]に基づいて定められる勾配線として定義されるプルーム範囲の、前記プルームの中心軸に垂直な方向の幅とする。 - 前記期間Td(it)内に前記降下煤塵評価地点iで捕集された降下煤塵試料の煤塵種を分類する煤塵種分類工程と;
前記捕集された降下煤塵試料のうち、前記煤塵種分類工程で分類されたいずれかの煤塵種に対して、前記降下煤塵評価地点iが発塵源か否かを判定する発塵源判定工程と;
を更に含むことを特徴とする、請求項14乃至17のいずれか1項に記載の降下煤塵の非定常発塵源位置の探索方法。 - 前記プルーム拡散幅σyおよびσzと、プルーム中心軸上の発生源からの距離xと、降下煤塵発生量QPと、前記代表風速WSと、定数Bと、前記プルーム拡散幅σyおよびσzを用いて定義されるプルーム範囲と、を用いて、プルーム中心軸上の発生源からの距離xでの煤塵濃度C(x)を表現する以下の式(1)及び(2)を、前記プルーム式として用いることを特徴とする、請求項21に記載の降下煤塵の非定常発塵源の探索方法。
C(x)=B(QP/2πσyσzWS) (プルーム範囲内) ・・・(A)
C(x)=0 (プルーム範囲外) ・・・(B)
ここで、(1)式および(2)式の単位は、全てSI単位であり、σzは、鉛直面内において、発生源を起点とするプルームの上端を[当該粒径区分における粒子落下速度下限値]/[代表風速]に基づいて定められる勾配線とするとともに、当該プルームの下端を[当該粒径区分における粒子落下速度上限値]/[代表風速]に基づいて定められる勾配線として定義されるプルーム範囲の、前記プルームの中心軸に垂直な方向の幅とする。
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