JP5923854B2 - Method for estimating concentration of substance component in fluid system, method for estimating concentration distribution, method for monitoring concentration, method for managing aluminum concentration in hot dip galvanized pot accommodated in hot dip galvanizing pot, and apparatus for estimating concentration of substance component in fluid system - Google Patents

Description

  The present invention relates to a concentration estimation method, a concentration distribution estimation method, a concentration monitoring method, an aluminum concentration management method in aluminum melt contained in a hot dip galvanizing pot, and a flow in a fluid system in which the material component has a concentration distribution. The present invention relates to a concentration estimation device for substance components in a system.

  In a fluid system with fluid facilities for industrial processes or spaces separated by walls, it is sufficient to monitor the concentration distribution of the substance components that make up the fluid in the fluid system. It is necessary to arrange a concentration measuring means for measuring the concentration by number and arrangement in the fluid. However, fluid facilities and industrial structures in industrial processes often have complicated shapes, and there are places where concentration measuring means cannot be arranged. Also, when the fluid is hot or highly corrosive, concentration measurement may be limited, and it is often impossible to install concentration measuring means with a sufficient number and arrangement to know the concentration distribution.

  In order to compensate for the lack of concentration measurement points and monitor the concentration distribution of the target component in the material components of the fluid system, it is necessary to estimate and interpolate the concentration distribution of the entire fluid system from the measured concentration values at several points. become. In a solid object, a well-known interpolation method such as spline interpolation is used to estimate and interpolate the density relatively easily in consideration of the geometric position of the density measurement point and the density estimation point. Yes. Also, an estimation method called an inverse distance weighting method is proposed in which various values including the density of the estimated point are estimated based on the distance between the estimated point and the actually measured point, and interpolated (for example, see Non-Patent Document 1). ).

Shepard, D.:A two-dimensional interpolating function for irregularly spaced data.Proc.ACM. Nat. Conf., 517-524, 1968.

The estimation method of Non-Patent Document 1 calculates the distance l _i between the position of the measured point i and the estimated point, weights the measured point with the larger distance l _i so that the weight becomes smaller, and estimates the estimated point as a weighted average. In this method, various values such as concentration are estimated using the following equation (1) with the power of the reciprocal of the distance (l / l _i ) as a weight.

式（１）において、Ｃｅ^Ｉは推定点における推定濃度、ｌ_ｉは濃度実測点ｉと濃度推定点ｊとの距離、ｕは正の値をとるパラメータ、Ｃ_ｉは濃度実測点ｉで計測された実測濃度値である。

In Equation (1), Ce ^I is measured at the estimated point, l _i is the distance between the measured concentration point i and the estimated concentration point j, u is a positive parameter, and C _i is measured at the measured concentration point i. The measured concentration value.

However, since the inverse distance weighting method of Non-Patent Document 1 uses a weight based only on the distance l _i between the density measurement point i and the density estimation point j and estimates the density by weighted average, the resulting density estimation result is obtained. Does not reflect the effect of fluid flow. For this reason, in a fluid system in which the flow contribution to the fluid component transport is very large, such as in an actual fluid process, the same concentration distribution is estimated even when the flow velocity is large and small even though the concentration distribution is greatly different. Therefore, it is difficult to apply to a fluid system in which transport of fluid components by fluid flow is dominant.

  The present invention has been devised in view of the above circumstances, and even for a fluid system having a complicated three-dimensional flow field, the arrangement of concentration measuring means is restricted from only a plurality of limited measured concentrations. It is an object of the present invention to provide a substance component concentration estimation method in a fluid system capable of estimating the concentration of a target component in the whole fluid without giving a fluid.

In order to achieve the above object, the present invention provides a method for estimating the concentration of a substance component in a fluid system in which the substance component has a concentration distribution, wherein the concentration is measured at two or more arbitrary concentration measurement points set in the fluid system. A concentration measurement step for measuring the concentration of the substance component by the concentration measuring means arranged at the measurement point, or measuring the concentration of the substance component in the sample collected at the concentration measurement point, and an arbitrary concentration estimation point set in the fluid system In the above, an index relating to the flow field of the fluid system at the concentration estimation point obtained experimentally or by numerical fluid simulation is obtained, and the substance at the concentration estimation point is obtained based on the index and the concentration measured in the concentration measurement step. It is seen including an estimation step of estimating the concentration of the component, and the index is, the fluid or the density estimate point from the concentration measured point A downstream transmission time required to move between and an upstream transmission time required for the fluid to move from the concentration estimation point to the concentration measurement point, and the estimation step includes the downstream transmission time and A weight function that is a monotonically non-increasing function with respect to the upstream transmission time is used to calculate a weight of the concentration measurement point with respect to the concentration estimation point, and a weighted average of the weight and the measured substance component concentration is calculated as the concentration It is estimated as the concentration of the substance component at the estimated point .

  Further, the concentration estimation method for the substance component in the fluid system according to the present invention is the above invention, wherein the estimation step includes calculating the weighting function of the concentration measurement point with respect to the concentration estimation point and calculating the downstream transmission time and the upstream side. A value with a smaller transmission time is selected as the minimum transmission time, and a weight of the concentration measurement point with respect to the concentration estimation point is calculated using a weight function that is a monotonous non-increasing function with respect to the minimum transmission time, and the weight and A weighted average with the measured substance component concentration is estimated as the concentration of the substance component at the concentration estimation point.

  The method for estimating the concentration of a substance component in a fluid system according to the present invention is the method for estimating the concentration of a substance component in a fluid system in which the supply and / or discharge of the substance component is performed unsteadily in the above invention. An estimation time designation step for designating a concentration estimation time at the estimation point, wherein the concentration measurement step measures the concentration of the substance component at the concentration measurement point in time series, and the estimation step includes the concentration estimation time. And the weighted average of the measured concentration and the weight at the concentration measurement point at the extraction time determined based on the downstream transmission time and the upstream transmission time is estimated as the concentration of the substance component at the concentration estimation point. The extraction time is a monotonically non-increasing function with respect to the downstream transmission time, and is monotonically non-decreasing with respect to the concentration estimation time and the upstream transmission time. Characterized in that a function.

  Further, the concentration estimation method of the substance component in the fluid system of the present invention is the above invention, wherein the extraction time is less than the downstream transmission time of the downstream transmission time and the upstream transmission time. If the upstream transmission time is smaller than the downstream estimation time from the concentration estimation time and the upstream transmission time is smaller, the concentration estimation is performed using the upstream transmission time after the concentration estimation time as the extraction time. The concentration of the substance component at a point is estimated.

The concentration estimation method for a substance components in the fluid system of the present invention, in the above invention, if the concentration of the previous SL material components in the concentrations actually measured point in the extraction time is not measured, the measurement time series densitometry interpolating the concentration in the extraction time from the value, the concentration of the pre-Symbol substance component concentration of the concentration estimate point estimating those extrapolated as measured concentration in the extraction time, or measured to the nearest time to the extraction time The concentration at the concentration estimation point is estimated as the actually measured concentration at the extraction time.

  Further, the concentration estimation method of the substance component in the fluid system according to the present invention is the above invention, wherein the fluid system is molten zinc in a hot dip galvanizing pot, and the estimating step is performed as a fluid in the hot dip galvanizing pot. The weight is calculated using the time taken for the molten zinc to move between the concentration measurement point and the concentration estimation point as the index, and the aluminum concentration in the molten zinc measured in the concentration measurement step is calculated as the substance component. As a concentration, the aluminum concentration in the molten zinc at the concentration estimation point in the hot dip galvanizing pot is estimated.

  The present invention is also a method for estimating a concentration distribution of a substance component in a fluid system in which the substance component has a concentration distribution, wherein the concentration of the substance component at all concentration estimation points set using the method described above is determined. It is estimated, and the concentration distribution of the substance component of the fluid system is obtained by interpolating the actually measured concentration with the estimated concentration.

  The present invention also relates to a method for monitoring the concentration of a substance component in a fluid system in which the substance component has a concentration distribution, and the concentration of an arbitrary cross-section from the concentration distribution data of the substance component in the fluid system estimated by the method described above. It is characterized by extracting distribution data and visualizing concentration distribution data of the extracted substance components.

  Further, the present invention is a method for managing the aluminum concentration in hot dip galvanized pot accommodated in a hot dip galvanizing pot, wherein the hot dip galvanizing pot in the hot dip galvanizing pot estimated by the method for estimating the concentration of substance components in the fluid system described above A concentration extraction step for extracting the concentration of aluminum in molten zinc in a predetermined region in the fluid system from the aluminum concentration data in molten zinc, and determining whether the extracted concentration is within a predetermined threshold range And a warning step that warns that when the concentration is determined to be outside the threshold range in the determination step.

Moreover, the hot dip galvanized steel sheet of the present invention is a hot dip galvanized steel sheet manufacturing method for manufacturing a hot dip galvanized steel sheet using the aluminum concentration control method in the hot dip zinc accommodated in the hot dip galvanizing pot described above. It is characterized by being manufactured using.

The present invention is also a substance component concentration estimation device in a fluid system in which the substance component has a concentration distribution, and at two or more arbitrary concentration measurement points set in the fluid system, the target component at the concentration measurement point Concentration measurement means for measuring the concentration of a substance or measuring the concentration of a substance component in a sample collected at the concentration measurement point, and a concentration estimation arbitrarily set in the fluid system obtained by experimental or numerical fluid simulation Storage means for storing an index related to the flow field of the fluid system at a point, an actual concentration of the substance component measured by the concentration measuring means, and an index related to the flow field of the concentration estimation point stored in the storage means based, and a concentration estimation means for estimating the concentration of a substance component in the concentration estimate point, the index is, the fluid is the density measured The downstream transmission time required to move from the concentration estimation point to the concentration estimation point, and the upstream transmission time required for the fluid to move from the concentration estimation point to the concentration measurement point, the estimation step, The weight of the concentration measurement point with respect to the concentration estimation point is calculated using a weight function that is a monotonous non-increasing function with respect to the downstream transmission time and the upstream transmission time, and the weight and the measured substance component concentration are calculated. It characterized that you estimate weighted average as the concentration of a substance component in the density estimate point.

  Further, the concentration estimation device for a substance component in a fluid system according to the present invention is the above invention, wherein the storage means stores concentration distribution data obtained by interpolating an actual measured concentration by the concentration of the substance component estimated by the concentration estimation means, Concentration data extraction means for extracting concentration distribution data of an arbitrary cross section from the concentration distribution data and visualizing the extracted concentration distribution data, and concentration distribution data of substance components of an arbitrary cross section visualized by the concentration data extraction means Display means for displaying.

  Further, in the fluid system according to the present invention, the concentration estimation device of the substance component in the above invention is characterized in that the concentration data extraction means extracts and extracts the concentration of the substance component in a predetermined region in the fluid system from the concentration distribution data. Determination means for determining whether or not the concentration is within a predetermined threshold range, and the display means displays a warning to that effect when the determination means determines that the concentration is outside the threshold range It is characterized by that.

  According to the present invention, since the concentration of the substance component in the fluid is estimated based on the index related to the flow field of the fluid system at the concentration estimation point obtained experimentally or by numerical fluid simulation, the substance component of the fluid flow is estimated. Concentration can be accurately estimated even for a fluid system in which transport is dominant. Further, the present invention can be applied not only to a simple one-dimensional flow fluid system but also to a fluid system having a wide range of fluid states, including a fluid system having a complicated three-dimensional flow.

FIG. 1 is a diagram illustrating an example of a fluid system model. FIG. 2 is a diagram for explaining the downstream transmission time in the fluid system of FIG. FIG. 3 is a correlation diagram of concentration and time for calculating the downstream transmission time in FIG. FIG. 4 is a diagram illustrating upstream transmission time in the fluid system of FIG. FIG. 5 is a correlation diagram of concentration and time for calculating the upstream transmission time in FIG. FIG. 6 is a flowchart showing a procedure for calculating the weight W using the numerical fluid simulation. FIG. 7 is a flowchart according to the density estimation process using the weight calculated in FIG. FIG. 8 is a flowchart of a concentration estimation process in a fluid system in which substance components are supplied and / or discharged unsteadyly using the weights calculated in FIG. FIG. 9 is a side view conceptually showing a water tank to which the present invention is applied. FIG. 10 is a top view of the water tank of FIG. FIG. 11 is a block diagram schematically illustrating a configuration example of the fluid concentration estimation apparatus according to the first embodiment of the present invention. 12 is a diagram showing a concentration distribution in a horizontal section passing through the center of the water tank in FIG. FIG. 13 is a diagram showing a concentration distribution in a horizontal section passing through the center of the aquarium estimated using the conventional method (reverse distance weighting method). FIG. 14 is a diagram showing an additional installation position of the concentration meter in the water tank. FIG. 15a is a diagram showing the time transition of the salt concentration measured at position P-11 in the water tank. FIG. 15b is a diagram showing the time transition of the salt concentration measured at position P-12 in the water tank. FIG. 15c is a diagram showing the time transition of the salt concentration measured at position P-13 in the water tank. FIG. 15d is a diagram showing a time transition of the salt concentration measured at the position P-14 in the water tank. FIG. 15e is a diagram showing the time transition of the salt concentration measured at the position P-15 in the water tank. FIG. 15f is a diagram showing a time transition of the salt concentration measured at the position P-16 in the water tank. FIG. 16a is a diagram showing a salt concentration distribution in a horizontal section passing through the center of the water tank of FIG. 9 (one minute after the inflow saline concentration change). FIG. 16b is a diagram showing a salt concentration distribution in a horizontal section passing through the center of the water tank of FIG. 9 (after two minutes from the change in influent saline concentration). FIG. 16c is a diagram showing a salt concentration distribution in a horizontal section passing through the center of the water tank of FIG. 9 (after 3 minutes from the change in influent saline concentration). FIG. 16d is a diagram showing a salt concentration distribution in a horizontal section passing through the center of the water tank in FIG. 9 (4 minutes after the change in influent saline concentration). FIG. 16e is a diagram showing a salt concentration distribution in a horizontal section passing through the center of the water tank of FIG. 9 (after 5 minutes from the change in influent saline concentration). FIG. 16f is a diagram showing a salt concentration distribution in a horizontal section passing through the center of the water tank in FIG. 9 (six minutes after the change in influent saline concentration). FIG. 17 is a side view conceptually showing a hot dip galvanizing pot to which the present invention is applied. FIG. 18 is a block diagram schematically illustrating a configuration example of the fluid-system concentration estimation apparatus according to the second embodiment of the present invention. FIG. 19 is a diagram showing an aluminum concentration distribution in the hot dip in a predetermined vertical section from the center of the sink roll axis of the hot dip galvanizing pot of FIG.

  Hereinafter, with reference to the accompanying drawings, the concentration estimation method, concentration distribution estimation method, concentration monitoring method, and aluminum concentration management method in the molten zinc contained in the hot dip galvanizing pot in the fluid system according to the present invention, and A preferred embodiment of a substance component concentration estimation apparatus in a fluid system will be described in detail. Here, the fluid system means a fluid that is a target of temperature estimation or concentration estimation, and surrounding parts that affect the flow behavior, thermal behavior, and substance concentration behavior of the target fluid, such as a fluid container, a structure in the fluid, A system including a heating device, a fluid inflow / outflow site, and the like. Note that in this specification, the fluid includes liquid substances such as liquid and gas, liquid substances that do not have a certain shape, such as liquid, and gaseous substances, as well as substances having fluidity, such as solid particles such as sand. .

  The present invention is applied to an object in which the flow of a fluid system is particularly important, for example, a fluid facility in which a container in which a fluid flows is partially partitioned by a partition plate. For such a fluid facility, as in Non-Patent Document 1 described above, the weight is calculated using only the geometric information of the distance between the concentration estimation point and the concentration measurement point as an index, and the concentration of the substance component is calculated by weighted averaging. When estimation is performed, density estimation is performed using the linear distance between the density estimation point and the density measurement point as an index regardless of the presence or absence of the partition plate, and thus a continuous density distribution is estimated beyond the partition plate. However, the actual substance component concentration is preferably because the fluid flow is blocked by the partition plate in the fluid facility and becomes discontinuous at the boundary of the partition plate, so that a concentration distribution greatly different from the actual concentration distribution is estimated. Absent.

Thus, as a result of careful consideration of a concentration estimation method that can successfully estimate even a concentration discontinuity phenomenon caused by a partition plate or the like, the present invention using the index based on the flow of the fluid system has been conceived. In the present invention, the time τ _1ij required for the fluid to move from the concentration measurement point i to the concentration estimation point j and the time τ _2ij required for the fluid to move from the concentration estimation point j to the concentration measurement point i by advection diffusion are _calculated . Used as an index for concentration estimation. And the two index values (τ _1ij, τ _2ij) to monotonically non-increasing function to become such a weight function f (τ _1ij, τ _2ij) used, the weight of the concentration measured point i in the density estimate point j W ( τ _1ij , τ _2ij ), and density estimation is performed based on each measured density value C _i and a weighted average using the weight.

Specifically, the relationship between the estimated density Ce _{j at} the density estimated point j and the density C _i at the actually measured density point i is expressed by Expression (2).

Since τ _1ij is the time required for the fluid to move in the direction of the concentration estimation point j on the downstream side of the flow as viewed from the concentration measurement point i, it is called the downstream transmission time. Similarly, τ _2ij is from the concentration measurement point i. Since this is the time required for the fluid to move from the direction of the concentration estimation point j on the upstream side of the flow, it is called the upstream transmission time. Further, hereinafter, a pair (τ _1ij , τ _2ij ) of downstream transmission time and upstream transmission time is referred to as transmission time. The transmission time may be an index corresponding to the time required for the fluid to move from the concentration measurement point i to the concentration estimation point j by the advection diffusion and the time required for the fluid to move from the concentration estimation point j to the concentration measurement point i. Any method may be used, and the definition method is not particularly limited.

  According to the principle of fluid dynamics, the time required for the fluid to move between two points in the fluid system is equivalent to the time required for the heat energy in the fluid and the substance component contained in the fluid to move between the two points. It is known. Therefore, the transmission time can be calculated by actually measuring or calculating the concentration of the fluid and the concentration and temperature of the component dissolved in the fluid. Therefore, the time required for the substance component to move from the concentration measurement point i to the concentration estimation point j by advection diffusion is the downstream transmission time, and the time required for the substance component to move from the concentration estimation point j to the concentration measurement point i. Can also be defined as upstream transmission time.

Here, a method for calculating the downstream transmission time τ _1ij and the upstream transmission time τ _2ij as the concentration estimation indexes in the fluid system by the movement of heat will be described with reference to FIGS. FIG. 1 is a diagram showing an example of a fluid system model in which a fluid is contained in a container having an open top. FIG. 2 is a diagram for explaining the downstream transmission time τ _1ij in the fluid system of FIG. FIG. 3 is a correlation diagram of concentration and time for calculating the downstream transmission time τ _1ij in FIG. FIG. 4 is a diagram for explaining the upstream transmission time τ _2ij in the fluid system of FIG. FIG. 5 is a correlation diagram of concentration and time for calculating the upstream transmission time τ _2ij in FIG.

  As shown in FIG. 1, the fluid system 1 contains a fluid 4 in a container 2 whose upper part is open, and a partition plate 3 that prevents the flow of the fluid 4 is disposed inside the container 2. A concentration measurement point i indicated by a black circle is arranged on the left side in the container 2 and a density estimation point j indicated by a white circle is arranged on the right side. As shown by the broken line, the fluid 4 in the container 2 flows from the left to the right in the vicinity of the upper liquid level, once descends at the partition plate 3 and then rises, and then descends again from the upper part to the lower part on the right wall surface. In the vicinity, the flow changes from the right to the left, and again flows from the bottom to the top on the left wall.

In the fluid system 1, the movement of the substance component from the concentration measurement point i arranged at the position P-1 shown by the black circle to the concentration estimation point j arranged at the position P-2 shown by the white circle is the fluid shown by the broken line arrow in FIG. It moves as indicated by the solid line arrow with the flow of 4. The downstream transmission time τ _1ij required for the substance component to move from the concentration measurement point i to the concentration estimation point j, as shown in FIG. 2, supplies the substance component at the position P-1 that is the concentration measurement point i, The measurement can be performed by measuring the substance component (solid line arrow in FIG. 2) that moves with the flow of the fluid 4 from the position P-1 at the position P-2 that is the concentration estimation point j. As shown in FIG. 3, the time required for the concentration to increase from the initial concentration C ₀ to the threshold concentration C _C at the concentration estimation point j can be calculated as the downstream transmission time τ _1ij .

Similarly, in the fluid system 1, the movement of the substance component from the concentration estimation point j arranged at the position P-2 indicated by the white circle to the concentration actual measurement point i arranged at the position P-1 indicated by the black circle is indicated by a broken line arrow in FIG. It moves as indicated by the solid line arrow along with the flow of the fluid 4 shown in FIG. The upstream transmission time τ _2ij required for the substance component to move from the concentration estimation point j to the concentration measurement point i supplies the substance component at the position P-2, which is the concentration estimation point j, as shown in FIG. The measurement is performed by measuring the substance component (solid arrow in FIG. 4) that moves with the flow of the fluid 4 from the position P-2 at the position P-1 that is the concentration measurement point i. As shown in FIG. 5, the time required for the concentration to increase from the initial concentration C ₀ to the threshold concentration C _C at the concentration measurement point i can be calculated as the upstream transmission time τ _2ij .

Alternatively, the transmission time can be calculated by supplying heat to the fluid and measuring the temperature rise with a thermometer. The concentration measurement point i and the concentration estimation point j of the fluid system are set, and heat is first generated at the position of the concentration measurement point i, and the temperature is measured using a thermometer at the position of the concentration estimation point j. The time τ _1ij required from when the heat is generated until the fluid temperature exceeds a certain threshold is measured. Furthermore, the transmission time (τ _1ij , τ _2ij ) is measured by generating heat at the concentration estimation point j, measuring the temperature at the position of the concentration measurement point i, and measuring the time τ _2ij required to exceed the threshold. Can do.

  Note that the transmission time can also be calculated by performing a numerical simulation similar to the above experiment using a numerical fluid simulation.

Hereinafter, the concentration calculation method at the concentration estimation point j will be described by taking as an example a method of calculating the transmission time using the numerical fluid simulation. First, a specific procedure of a method for calculating the weight W (τ _1ij , τ _2ij ) in the above equation (2) will be described with reference to FIG. FIG. 6 is a flowchart showing a procedure for calculating the weight W (τ _1ij , τ _2ij ) using the numerical fluid simulation.

  First, a representative boundary condition of a fluid system is set using a numerical fluid simulation (step S101), and then a flow field is calculated based on the set boundary condition (step S102).

  The flow field calculation can be performed two-dimensionally or three-dimensionally according to the characteristics of the target fluid system. For the flow field calculation, any fluid analysis solver can be used as long as it is a fluid analysis solver that can calculate the flow field and the concentration field of the fluid. For example, the flow field calculation is performed by ANSYS FULL (registered trademark) or the like. be able to.

Next, a fluid concentration measurement point i (i = 1 to N) and a concentration estimation point j (j = 1 to M) are set (step S103), and the set concentration measurement point i (i = 1 to N) is set. Then, the density measurement point i and the density estimation point j for calculating the weight W _ij from the density estimation point j (j = 1 to M) are designated (step S104). Note that the number N of actually measured density points is set to at least two.

Subsequently, the initial concentration C ₀ (mass%) is given to the entire fluid system (step S105), and the substance component supply amount S (kg / s) is set at the position of the concentration measurement point i (step S106). Under these conditions, the concentration distribution is unsteadyly calculated (step S107), and the concentration rising behavior at the concentration estimation point j is calculated. When the density at the density estimation point j reaches the threshold density C _C (mass%), the time τ _1ij taken until the density reaches C _C from C ₀ is recorded (step S108). τ _1ij is the downstream transmission time. Since the initial concentration C ₀ (mass%) is a value that does not affect the transmission time, any value may be given. Regarding the substance component supply amount S (kg / s) and the threshold concentration C _C (mass%), the optimum values differ depending on the target fluid system. For example, in a general case of a hot dip galvanizing pot, a hot metal holding furnace, and a tundish, it may be set to about S = 50 (kg / s) and C _C = C ₀ +1 (mass%).

Similarly, after the initial concentration C ₀ is given to the entire fluid system (step S109), the substance component supply amount S (kg / s) is given to the position of the concentration estimation point j (step S110), and the concentration distribution is unsteady. Calculation is performed (step S111), and the time τ _2ij taken until the density at the density measurement point i reaches C _C from C ₀ is recorded (step S112). τ _2ij is the upstream transmission time.

After obtaining the transmission time (τ _1ij , τ _2ij ) between the concentration measurement point i and the concentration estimation point j as described above, a weight function W (τ _1ij , τ _2ij ) such as a Gaussian distribution function described later is obtained. _Is used to calculate the weight W _ij (step S113).

Here, the weighting function W (τ _1ij, τ _2ij) becomes a monotonically non-increasing function of tau _1ij for any tau _2ij, and such that the monotonically non-increasing function of tau _2ij for any tau _1ij It is a function. That is, it is a function which becomes the following formula (3).

The optimum function form of W (τ _1ij , τ _2ij ) _{varies depending on} the spatial scale, flow velocity scale, concentration measurement point arrangement interval, etc. of the fluid system. It is most desirable to use a Gaussian distribution function using the minimum transmission time shown in Equation (4).

In Expression (4), τ _min is the minimum transmission time, and is defined as the smaller value of (τ _1ij , τ _2ij ). σ is a standard deviation of the Gaussian distribution. When σ is increased and estimated / interpolated, a spatially smoothed concentration distribution is obtained, and when σ is decreased and estimated / interpolated, a steep concentration distribution is obtained. The optimum value of σ varies depending on the target fluid system, but in the case of a general hot dip galvanizing pot, σ = 60 sec may be used.

Also, if there is a substance component supply source or substance component discharge source in the vicinity of the concentration measurement point i and the substance component supply source or substance component discharge source is upstream of the flow as viewed from the concentration measurement point i, the weight The function W uses a Gaussian distribution function (the following expression (5)) using the downstream transmission time τ _1ij instead of the expression (4).

Similarly, when there is a substance component supply source or substance component discharge source in the vicinity of the concentration measurement point i, and the substance component supply source or substance component discharge source is on the downstream side of the flow as viewed from the concentration measurement point i, As the weighting function W, a Gaussian distribution function (the following expression (6)) using the upstream transmission time τ _2ij is used instead of the expression (4).

The weight W _ij is calculated as described above. In order to estimate and visualize the concentration distribution of the entire fluid system, each concentration measurement is performed for the concentration estimation point j (j = 1 to M) set for the entire fluid system. It is preferable to calculate a weight W _ij between the points i (i = 1 to N) (step S114) and store the calculated weight W _ij as a database (step S115).

As described above, after obtaining the weights W _ij, it calculates the concentration at any concentration estimate point j using the weight W _ij. Next, the density estimation process at the density estimation point j will be described with reference to FIG. FIG. 7 is a flowchart according to the density estimation process using the weight W _ij calculated by the process of FIG.

First, in the fluid system, the concentration is measured by the concentration measuring means at the set concentration actual measurement point i (i = 1 to N), and the actually measured concentration value C _i (i = 1 to N) is acquired (step S201). Subsequently, the density estimation point j for estimating the density is designated (step S202), and the weight W _ij (i = 1 to N) for each density measurement point i (i = 1 to N) with respect to the designated density estimation point j. Is acquired from the database (step S203). The measured density value C _i (i = 1 to N) acquired in step S201 and the weight W _ij (i = 1 to N) acquired in step S202 are applied to the following equation (7) to perform weighted averaging processing. to calculate the estimated concentration Ce _j to the concentration estimate point j (step S204).

On the other hand, in the case where the supply and / or discharge of the substance component is performed non-stationarily in the same fluid system and the concentration that varies with time is estimated, the concentration estimation time ta is designated, and the concentration estimation time ta after determining the extraction time tb _ij by the downstream-side transmission time tau _1ij and the upstream transmission time tau _2ij is indicative of the fluid system of the flow field, it is preferable to estimate the concentration Ce _j. In the present invention, the weight of the concentration measurement point i with respect to the concentration estimation point j using the weight function W (τ _1ij , τ _2ij ) that is a monotonically non-increasing function with respect to the downstream transmission time τ _1ij and the upstream transmission time τ _2ij. W _ij is calculated, and the weighted average of the weight W _ij and the actually measured concentration C _i is estimated as the concentration Ce _j of the concentration estimation point j. However, the substance component is supplied and / or discharged unsteadily. In the system, the density C _i of the density measurement point _i also varies with time. Therefore, when the downstream transmission time τ _1ij and / or the upstream transmission time τ _2ij is large, when the concentration of the substance component at the concentration estimation point j at the concentration estimation time ta is estimated, the actually measured concentration C _i of the concentration estimation time ta. If (ta) is used as it is for the calculation of the weighted average, the flow field cannot be reflected and accurate estimation may not be performed. For this reason, when estimating the concentration of the substance component in the fluid system in which the supply and / or heat discharge of the substance component is performed unsteadily, the extraction time tb considering the flow field of the fluid system with respect to the concentration estimation time ta _{By using} the measured concentration C _i (tb _ij ) of _ij for calculation of the weighted average, the concentration estimation point j varies with time in a fluid system in which substance components are supplied and / or discharged non-stationarily. it is possible to estimate the concentration Ce _j material composition more accurately.

Also in the fluid system in which the supply and / or discharge of the substance component is performed unsteadyly, the downstream transmission time τ _1ij and the upstream transmission time τ _2ij are calculated using numerical fluid simulation in the same manner as described above. The weight W _ij is calculated using the weight function W (τ _1ij , τ _2ij ) that is a monotonically non-increasing function, and the calculated weight W _{ij, the} downstream transmission time τ _1ij , and the upstream transmission time τ _2ij are _stored in the database. Store as.

The concentration of the substance component at the concentration estimation point j is calculated using the weight W _ij and the actually measured concentration value C _i (tb _ij ) at the extraction time tb _ij . The density estimation process at the density estimation point j will be described with reference to FIG. FIG. 8 is a flowchart according to the density estimation process using the weight W _ij calculated by the process of FIG. 6 and the actually measured density value C _i (tb _ij ) at the extraction time tb _ij .

First, at the set concentration actual measurement point i (i = 1 to N), the time transition of the concentration C _i of the substance component is measured, and the time series concentration actual measurement value C _i (t) [i = 1 to N, t is Measured time] is acquired (step S301). Subsequently, the concentration estimation point j for estimating the concentration of the substance component is designated (step S302), and the concentration estimation time ta that is the time for estimating the concentration is designated (step S303). Then, the downstream transmission time τ _1ij , the upstream transmission time τ _2ij, and the weight W _ij (i = 1 to N) for each concentration measurement point i (i = 1 to N) with respect to the designated concentration estimation point j are stored from the database. Obtained (step S304), the concentration extraction time tb _ij = tb (ta, τ _1ij , τ _2ij ) is determined from the obtained downstream transmission time τ _1ij , upstream transmission time τ _2ij and concentration estimation time ta ( Step S305). Here tb (ta, tau _1ij, tau _2ij), as shown in the following equation (8), monotone nonincreasing function and ta of tau _1ij, a monotonically non-decreasing function of tau _2ij.

The extraction time function tb (ta, τ _1ij , τ _2ij ) can be of various functional systems, but the extraction time function tb _{ij that} can be used for a relatively wide range of objects is preferably expressed by the following equation (9). That is, if the downstream transmission time τ _1ij is smaller than the upstream transmission time τ _2ij , the time before the concentration estimation time ta by the downstream transmission time τ _1ij is taken as the extraction time tb _ij , and the upstream transmission time τ _2ij is the downstream side If it is _shorter than the transmission time τ _{1ij, the} time after the upstream side transmission time from the concentration estimation time ta is set as the extraction time tb _ij .

The actually measured density value C _i (tb _ij ) [i = 1 to N] at the extraction time tb _ij determined in step S305 is acquired from the time-series measured density value C _i (t) obtained in step S301, and in step S304. the acquired weights _W ij (i = 1 to N) and the density measured value _C i _{(tb ij),} performs averaging weighted by applying the following equation (10), the estimated concentration Ce _j to the concentration estimate point j Calculate (step S306). When there are a plurality of density estimation points j, Steps S301 to S306 are repeated, and the estimated density Ce _j at each density estimation point j (j = 1 to M) is repeatedly calculated.

If the measured concentration value C _i (tb _ij ) at the extraction time tb _ij is unknown, the concentration at the extraction time is interpolated or extrapolated from the known concentration data, or measured at the time closest to the extraction time tb _ij . The concentration of the substance component may be set to the actually measured concentration value C _i (tb _ij ). For example, when the concentration is estimated in real time, all the actually measured concentration values C _i in the time after the current time are unknown. At this time, in a certain concentration estimate point i and the concentration measured point j, when the upstream transmission time tau _2ij is smaller than the downstream transmission time tau _1ij, extraction time tb _ij is than the current time for a subsequent time, The actually measured density value C _i is unknown. In such a case, for example, the current time t may be used as the extraction time tb _ij and the currently measured concentration C _i (t) may be used as the actually measured concentration value C _i .

As described above, concentration estimation points j (j = 1 to M, a plurality of Ms) are arranged throughout the fluid system, and weights W _ij for the concentration measurement points i are created for the respective concentration estimation points j. By storing in the database, as shown in FIG. 7, a plurality of density estimations are obtained simply by reading the actually measured density values C _i (i = 1 to N) and the weights W _ij and substituting them into the equation (7). to calculate the concentration Ce _j at point j, it is possible to estimate the concentration distribution of the entire fluid system instantaneously. Further, in addition to the weight W _ij of each concentration estimation point j and the concentration actual measurement point i, the downstream transmission time τ _1ij and the upstream transmission time τ _2ij are stored in the database, thereby supplying the substance components and In a fluid system in which discharge is performed _unsteadily , an extraction time tb _ij considering the flow field of the fluid system is determined by a concentration estimation time ta, a downstream transmission time τ _1ij and an upstream transmission time τ _2ij. 8, by simply substituting the measured concentration value C _i (tb _ij ) and the weight W _{ij of} the extraction time tb _ij into the equation (10), the substance components at a plurality of concentration estimation points j can be obtained. to calculate the concentration Ce _j, it is possible to estimate the concentration distribution of a substance component of the entire fluid system instantaneously. Therefore, it can be fully used for online monitoring of industrial processes that require real-time calculation, and can be used for operation management and control mechanisms. Further, in the present invention, since the concentration of the substance component at an arbitrary position in the fluid system can be estimated, it is possible to obtain the concentration of a part where concentration measurement is difficult, and the substance component in the fluid system can be obtained with high accuracy. It is possible to grasp the concentration.

  On the other hand, when the above-described concentration estimation result is visualized by an isoline map or the like, the concentration estimation point j is preferably arranged by spatial decomposition that can reproduce the phenomenon of interest. For example, when monitoring the concentration distribution of the hot dip galvanizing bath, it is desirable to have a resolution higher than the level that can reproduce the shape of the structure inside the fluid such as a roll in the bath or a steel plate. However, according to the density estimation method of the present invention, the accuracy of density estimation at each point does not deteriorate even if the space between the estimated points of the space is rough. Therefore, a resolution that can reproduce all physical phenomena is not necessarily required. It may be adjusted by increasing or decreasing the number of density estimation points. In addition, the visualization may be expressed as an isoline diagram in which points having the same density are connected by a curve, or the isoline diagram may be colored or the density may be indicated only by color.

Note that the concentration distribution of the substance component at two different times t and t + Δt (Δt> 0) is calculated as the monitoring device by the above method, and the concentration estimation at time t is calculated from the concentration estimated value at time t + Δt. A method of calculating and showing a value obtained by subtracting the value is also effective. When this method is used, a positive value is obtained when the concentration increases with time, and a negative value is obtained when the concentration is decreasing. Therefore, it is easy to grasp the distribution of concentration changes. The optimum time width Δt varies depending on the time scale of the phenomenon to be observed. For example, since various time scale phenomena occur in a hot dip galvanizing pot, it is preferable to acquire a concentration change distribution over a plurality of time widths Δt from about 1 minute to about 1 hour. In the case where the concentration monitoring of the substance component is performed, the method of formula (9) and formula (10) for estimating the concentration of the substance component in the fluid system in which the supply and / or discharge of the substance component is performed unsteadily. it is preferable to use a concentration estimated value Ce _j by.

(Embodiment 1)
As Embodiment 1 of the present invention, concentration estimation of substance components in a water tank and visualization of concentration distribution will be described. FIG. 9 is a side view conceptually showing a water tank to which the first embodiment of the present invention is applied. FIG. 10 is a top view of the water tank of FIG.

  As shown in FIGS. 9 and 10, the water tank 100 includes a rectangular parallelepiped container 110 having a depth direction of 1 m, a width direction of 1 m, and a depth of 0.5 m, and the container 110 is filled with a saline solution. Pipes 101 and 102 are arranged at both left corners of the water tank 100 so that water and saline are injected, respectively. Water is injected from the pipe 101 and saline solution having a concentration of 10 mass% is injected from the pipe 102. A pipe 103 is also arranged at the center on the right hand side of the water tank 100 so that the same amount of saline solution as the total amount of water flowing in from the pipes 101 and 102 flows out.

  In addition, a partition plate 104 that divides only half of the width direction of the water tank 100 is disposed in the water tank 100, and the vertical cross section 105 that passes through the center of the water tank 100 is disposed closer to the pipe 101 side by 0.2 m. It has become. The electric conductivity meter 106 (106-1, 106-2, 106-3, 106-4, 106-5, 106-6) is located at the positions (P-11, P- 12, P-13, P-14, P-15, P-16). The arrangement of the electric conductivity meter 106 in the depth direction was set at a position that is exactly the center depth of the water tank 100.

  FIG. 11 is a block diagram schematically showing a configuration example of the fluid-system concentration estimation apparatus 200 according to the first embodiment of the present invention. Hereinafter, the salt concentration estimation and concentration distribution visualization in the water tank 100 of FIG. 9 by the concentration estimation apparatus 200 will be described. As shown in FIG. 11, the concentration estimation apparatus 200 includes an input unit 201, a display unit 202, a storage unit 203, and a control unit 204.

  The input unit 201 inputs information necessary for estimating the concentration of saline in the water tank 100. The input unit 201 is realized using a keyboard, a touch panel, a mouse, or the like. Information input by the operator via the input unit 201 is input to the control unit 204.

  The display unit 202 displays concentration information estimated by a concentration estimation unit 205, which will be described later, and a concentration data extraction unit 206 that extracts the concentration of a specific cross section of the water tank 100, and displays the concentration distribution information converted into an isogram. The display unit 202 is realized using various displays such as a CRT display, and displays various types of information that are controlled by the control unit 204.

The storage unit 203 stores the weight W _ij calculated for each concentration measurement point i and concentration estimation point j set in the water tank 100 as a database. The density distribution data estimated and created by the density estimation unit 205 is also stored and stored. The storage unit 203 stores data for various IC memories such as RAM or flash memory, or a hard disk and an optical disk such as a floppy (registered trademark) disk, a CD (Compact Disk) or a DVD (Digital Versatile Disk), or a magneto-optical disk. And a drive capable of reading or writing.

  The control unit 204 performs drive control of each component of the concentration estimation apparatus 200, input / output control and information processing for information input / output to / from each component. The control unit 204 includes a density estimation unit 205 and a density data extraction unit 206. The control unit 204 is realized using a CPU or the like.

The concentration estimation unit 205 is configured to measure the actual measured concentration C _i of the saline solution at the measured concentration point i measured by the electric conductivity meter 106 disposed in the water tank 100, and the measured concentration point i and the concentration estimation stored in the storage unit 203. The weight W _ij calculated for each point j is acquired via the control unit 204, and the density Ce _j of the density estimation point j is estimated based on the acquired information. In addition, the concentration estimation unit 205 estimates the concentration of the concentration estimation point j set for the entire water tank 100, creates concentration data obtained by adding the position information of the concentration estimation point j to the estimated concentration, and uses the concentration data to generate a concentration data. The measured density C _i at the measured point i is interpolated to obtain density distribution data. The control unit 204 stores the density distribution data created by the density estimation unit 205 in the storage unit 203.

  The concentration data extraction unit 206 sets the estimated concentration data of the salt solution in an arbitrary section of the water tank 100 that is set in advance from the concentration distribution data stored in the storage unit 203 or specified by the operator via the input unit 201. Extract and plot contours.

In the first embodiment of the present invention, the transmission time for calculating the weight W _ij stored in the storage unit 203 is calculated using a numerical fluid simulation. The numerical fluid simulation uses a finite volume method and a standard k-ε turbulent model as a turbulent model. In the flow field calculation in step S102 of FIG. 6 described above, water flows in from the upper end of the pipe 101 at a flow rate of 0.765 L / s, water flows in from the upper end of the pipe 102 at a flow rate of 1.531 L / s, and pressure is generated at the lower end of the pipe 103. The calculation was performed by giving a boundary condition as a slip condition for the upper surface of the water tank 100 and a wall boundary condition using the logarithm of the wall for the upper surface of the water tank 100. Moreover, the calculation of the transmission time in steps S103 to S112 in FIG. 6 was performed assuming that the initial concentration of saline is 0 mass%, the supply amount of salt is 45 kg / s, and the threshold concentration is 1 mass%. The concentration estimation points j were arranged at intervals of 0.04 m and arranged throughout the water tank.

The weight function W (τ _1ij , τ _2ij ) is a Gaussian distribution using a minimum transmission time τ _min with a standard deviation σ = 60 s. However, in order to simplify the calculation, the weight is set to 0 when τ _min > 180 s. That is, the weight function W (τ _1ij , τ _2ij ) is set to the following expression (11).

Table 1 shows the measured concentrations at each position (P-11, P-12, P-13, P-14, P-15, P-16) in the water tank 100 by the electric conductivity meter 106.

The concentration estimation unit 205 uses the concentration actual measurement data shown in Table 1 and the weight W _ij calculated by the equation (11) and stored in the storage unit 203 to determine the concentration of the concentration estimation point j set for the entire aquarium 100. to estimate the Ce _j. The concentration estimating unit 205 creates a density data obtained by adding the position information of the concentration estimate point j to the estimated concentration, the measured concentration Ce _i concentrations measured point i, which is measured by the electric conductivity meter 106 by the concentration data Interpolated into density distribution data. The control unit 204 stores the density distribution data in the storage unit 203. Here, the concentration distribution of the saline solution in a horizontal section passing through the center of the water tank 100 is extracted from the concentration distribution data of the storage unit 203 by the concentration data extraction unit 206 and is converted into an isoline diagram, which is shown in FIG. FIG. 12 is a diagram showing the concentration distribution of the saline solution in a horizontal section passing through the center of the water tank 100 estimated by the method of the first embodiment of the present invention.

  Further, as a comparative example, the weight function W is calculated using the inverse distance weighting method, the concentration is estimated by the same procedure as in the first embodiment of the present invention, and the salt in the horizontal section passing through the center of the water tank 100 from the estimated concentration. FIG. 13 shows an isoline diagram obtained by extracting the water concentration distribution. FIG. 13 is a view showing a concentration distribution of saline solution in a horizontal section passing through the center of the water tank 100 estimated by using a conventional method (reverse distance weighting method).

In the inverse distance weighting method as a comparative example, the following equation (12) was used as the weight W _ij ′.

Here, l _ij is a linear distance between the actually measured density point i and the estimated density point j, and u is an interpolation parameter. I gave u = 2 this time. As in the case of the first embodiment, the salt concentration of the entire aquarium 100 is estimated using the concentration actual measurement data shown in Table 1 and the weight W _ij ′ calculated by the equation (12). The concentration distribution of the saline solution in the horizontal cross section was extracted and plotted as an isoline diagram.

  Comparing the first embodiment of the present invention and the comparative example, as shown in FIGS. 12 and 13, in the first embodiment, the concentration distribution of the saline solution is discontinuous with the partition plate 104 as a boundary. A concentration distribution reflecting the influence of the flow field rectified by the plate 104 can be constructed. On the other hand, in the comparative example, the salt concentration is continuously interpolated over the partition plate 104, and the influence of the flow field rectified by the partition plate 104 cannot be reflected. From the above, it has been confirmed that Embodiment 1 can reflect the influence of the flow field more than the conventional inverse distance weighting method.

  Further, in order to quantitatively verify the concentration estimation accuracy of the saline solution in the water tank 100, an electric conductivity meter 106 (106-7, 106-8, 106-9) is provided in the water tank 100 as shown in FIG. In addition to measuring the saline concentration at each position (P-17, P-18, P-19) where the electric conduction timepiece 106 is additionally installed, the position of the position is determined according to the first embodiment and the comparative example. The saline concentration of P-17, P-18, and P-19 was estimated. FIG. 14 is a diagram showing an additional installation position of the electric conductivity meter 106 in the water tank 100. In addition, arrangement | positioning of the depth direction of the water tank 100 of the electric conductivity meter 106 installed additionally was made into the position used as the exact center depth of the water tank 100. FIG.

  Table 2 shows measured concentrations at positions P-17, P-18, and P-19 where electric conductivity meters are additionally installed, estimated concentrations according to the first embodiment, and estimated concentrations according to the comparative example. In contrast to the comparative example, in the first embodiment, the saline concentration at each of the positions P-17, P-18, and P-19 is close to the actual measurement value, and the concentration estimation accuracy according to the first embodiment is high. Was confirmed to be excellent.

  As described above, according to the first embodiment, the concentration of the substance component constituting the fluid can be visualized in an arbitrary cross section of the fluid system including the water tank 100 and the like. It can be captured visually. Further, in the first embodiment, since a desired substance component concentration can be estimated at an arbitrary position of the fluid system, even in a fluid system that is difficult to sample or in a fluid system that has a space partitioned by walls, It is possible to obtain the concentration of the substance component. Furthermore, in addition to the above effects, the first embodiment can predict the concentration distribution of the desired substance component in the entire fluid system in a very short time, so the concentration distribution can be estimated and visualized online, and the operation of the fluid equipment There is an advantage that can be used for management.

(Modification 1 of Embodiment 1)
As a first modification of the first embodiment of the present invention, salt concentration distribution estimation is performed in the same water tank as the first embodiment when the salt concentration changes over time. Water always flows from the pipe 101. It is assumed that a constant flow rate of water or saline flows from the pipe 102. First, water that does not contain salt flows in, and a salt solution having a concentration of 10 mass% is injected from the middle. The electric conductivity meter 106 (106-1, 106-2, 106-3, 106-4, 106-5, 106-6) is located at the same position (P-11, P-12, P-) as in the first embodiment. 13, P-14, P-15, P-16).

In the first modification, the downstream transmission time τ _1ij , the upstream transmission time τ _2ij , and the weight W _ij are calculated using the numerical fluid simulation as in the first embodiment. The numerical fluid simulation uses a finite volume method and a standard k-ε turbulent model as a turbulent model. In the flow field calculation, water flows from the upper end of the pipe 101 at a flow rate of 0.765 L / s, water or saline flows from the upper end of the pipe 102 at a flow rate of 1.531 L / s, and flows out at a lower pressure at the lower end of the pipe 103. The calculation was performed with the boundary condition given as the wall boundary condition using the logarithm rule of the wall and logarithm of the wall and the bottom wall. In addition, the calculation of the transmission time was performed assuming that the initial concentration of saline is 0 mass%, the supply amount of salt is 45 kg / s, and the threshold concentration is 1 mass%. The concentration estimation points j were arranged at intervals of 0.04 m and arranged throughout the water tank.

The weighting function W (τ _1ij , τ _2ij ) is a Gaussian distribution using the standard deviation σ = 60 s and the minimum transmission time τ _min in the equation (11), as in the first embodiment. The time transition of the salt concentration measured at each position (P-11, P-12, P-13, P-14, P-15, P-16) in the water tank 100 by the electric conductivity meter 106 is shown in FIG. As shown in FIG. FIGS. 15a to 15f are diagrams showing the time transition of the salt concentration measured at each position (P-11, P-12, P-13, P-14, P-15, P-16) in the water tank. is there. In FIGS. 15a to 15f, time 0 minutes is the time when the saline concentration of the water flowing from the pipe 102 changes.

For salt concentration distribution in a horizontal section passing through the center of the water tank 100, the time transition data of the actual measured concentration values C _i (t) measured in the above P-11 to P-16, and the equations (9) and (10) are used. Thus, the concentration Ce _j was estimated. As the concentration estimation time ta, 6 points are considered 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes and 6 minutes after the time when the saline concentration of the pipe 102 is changed to 10 mass%, Isolines were plotted for each. 16a to 16f are diagrams showing a salt concentration distribution in a horizontal section passing through the center of the water tank of FIG. 9, and one minute after the time when the concentration of the salt solution flowing out from the pipe 102 is changed to 10 mass% (FIG. 16a). ) Isoline plots of saline concentration after 2 minutes (FIG. 16b), after 3 minutes (FIG. 16c), after 4 minutes (FIG. 16d), after 5 minutes (FIG. 16e) and after 6 minutes (FIG. 16f). It is. When the saline concentration in the pipe 102 changes from 0 mass% to 10 mass%, the state in which the salt concentration gradually rises from a position close to the pipe 102 appears well, and even if there is a time transition of the concentration distribution, the concentration distribution I was able to estimate.

(Embodiment 2)
A hot dip galvanizing line using hot dip galvanizing pots is one of steel processes for producing galvanized steel sheets used for automobiles and building materials, and hot dip galvanizing pots as shown in FIG. 17 are used. In the hot dip galvanizing line, the steel plate 303 is dipped in the hot dip zinc in the plating pot 301 from the snout, changed in direction by the sink roll 302, pulled up from the plating pot 301, and after adjusting the coating amount by a non-illustrated adhesion amount control device. Then, it is cooled and subjected to a predetermined post-treatment to obtain a required plated steel sheet. In order to compensate for the reduced plating metal adhering to the steel plate 303, a zinc-based solid phase metal ingot 304 is melted in the plating pot 301.

In the hot dip galvanizing pot 300, while the steel plate 303 passes through the plating pot 301, iron eluted from the steel plate 303 reacts with zinc as a main component in the plating bath and aluminum added in a small amount, thereby producing zinc iron aluminum. The intermetallic compound comprised from the so-called dross is produced. The surface defect of the plated steel sheet caused by the dross adhering to the hot dip galvanized steel sheet is the most serious problem among hot dip galvanized steel sheets. What is particularly serious is an intermetallic compound (FeZn ₇ or the like) produced by a reaction between iron and zinc eluted from a steel sheet, and is called a bottom dross, and its size is 5 to 300 microns in diameter in terms of a sphere. Since dross changes its generation behavior greatly depending on the concentration distribution of iron and aluminum in the molten zinc bath, it is extremely important to control the concentration distribution of iron and aluminum in the molten zinc bath.

  In the second embodiment of the present invention, the estimation of the concentration of aluminum in the molten zinc accommodated in the hot dip galvanizing pot 300 that solves the above problem and the visualization of the concentration distribution will be described.

  As shown in FIG. 17, in the hot dip galvanizing pot 300, the capacity of hot dip zinc in the plating pot 301 is 250 (t), and the operating conditions are a line speed of 130 (mpm) and a plate width of 1,500 (mm). . Zinc and aluminum consumed by adhesion to the steel plate 303 are replenished by charging the ingot 304. In order to estimate the concentration distribution of aluminum in the hot dip zinc accommodated in the hot dip galvanizing pot 300, eight sample collection positions (P-21, P-22, P-23, P-24 in the plating pot 301). , P-25, P-26, P-27, P-28).

  Table 3 shows sample collection positions. The sample collection positions (P-21, P-22, P-23, P-24, P-25, P-26, P-27, P-28) are vertical sections passing through the center of the sink roll 302 in FIG. This represents the distance (front direction) from.

In the second embodiment, as in the first embodiment, the flow field and the transmission time τ _ij are calculated using a numerical fluid simulation. The numerical fluid simulation uses a finite volume method and a standard k-ε turbulent model as a turbulent model. The transmission time τ _ij was calculated as an initial aluminum concentration C ₀ = ₀ mass% in the plating pot 301, an aluminum charging rate S = 44 kg / s, and a threshold concentration C _c = 1 mass%. The concentration estimation points j were arranged in a grid pattern with an interval of 0.2 (m), and were arranged throughout the molten zinc bath.

The weight function W (τ _1ij , τ _2ij ) is a Gaussian distribution using the standard deviation σ = 60 (s) and the minimum transmission time τ _min . However, in order to simplify the calculation, the weight is set to 0 when τ _min > 180 (s). That is, the weight function W (τ _1ij , τ _2ij ) is set to the following expression (13). The calculated weight W _ij is stored as a database in the storage unit 403 shown in FIG. _{Alternatively} , the transmission time τ _ij may be stored and calculated each time using equation (13). FIG. 18 is a block diagram schematically illustrating a configuration example of the fluid-system concentration estimation apparatus 400 according to the second embodiment of the present invention.

Table 4 shows the actual measured values of the concentration of aluminum in the molten zinc contained in the plating pot 301 analyzed off-line by high frequency inductively coupled plasma (ICP) emission spectroscopy for the sample collected at the sample collection position shown in FIG. Shown in

The aluminum concentration of the molten zinc bath analyzed off-line is input via the input unit 401 by the operator. The concentration estimation unit 405 uses the actually measured aluminum concentration data shown in Table 4 and the weight W _ij calculated as equation (13) and stored as a database in the storage unit 403 as a concentration estimation set for the entire plating pot 301. The aluminum concentration at point j is calculated. Also, the concentration estimation unit 405 creates concentration data obtained by adding the position information of the concentration estimation point j to the estimated concentration, and is collected and analyzed at the sample collection position (concentration measurement point i) based on the concentration data. _i is interpolated to obtain density distribution data. The control unit 404 stores the density distribution data in the storage unit 403. The concentration data extraction unit 406 estimates the aluminum in the molten zinc of an arbitrary cross section of the plating pot 301 that is preset from the concentration distribution data stored in the storage unit 403 or specified by the operator via the input unit 401. Extract density data and plot it as an isoline diagram. Alternatively, after calculating the aluminum average concentration of the molten zinc bath from the extracted concentration data, a difference value from the average concentration in the cross section may be calculated, and the difference value may be converted into an isoline diagram.

  FIG. 19 shows an isoline diagram of the difference value from the average aluminum concentration of the molten zinc bath in a vertical cross section of 1.5 mm from the center of the sink roll axis of the plating pot 301 to the near side. According to FIG. 19, the aluminum concentration distribution result of the molten zinc bath by the method of the second embodiment also reflects the influence of the flow in the molten zinc, and the second embodiment shows the flow effect of the molten zinc. It is possible to construct an aluminum concentration distribution considering the above.

  In the second embodiment, as shown in FIG. 18, the control unit 404 includes a determination unit 407 in addition to the concentration estimation unit 405 and the concentration data extraction unit 406. The determination unit 407 is a predetermined region in the plating pot 301, for example, a location where the surface of the steel plate 303 affecting the surface defect contacts the molten zinc, a location where the sink roll 302 and the molten zinc contact, or the sink roll 302. It is determined whether or not the aluminum concentration in the molten zinc in the region surrounded by the upper portion and the steel plate 303 is within a predetermined threshold. The threshold value of the aluminum concentration is input in advance to the determination unit 407 or input by the operator via the input unit 401, and the determination unit 407 determines the aluminum concentration in the molten zinc in the predetermined region extracted by the concentration data extraction unit 406. It is determined whether the concentration is within a threshold set as the target concentration of aluminum in the molten zinc bath. When the determination unit 407 determines that the aluminum concentration in the molten zinc in the predetermined region is outside the threshold range, the display unit 402 displays that the aluminum concentration in the molten zinc in the predetermined region is outside the threshold value, and operates. Alert the person. According to the second embodiment, the operator can control the aluminum concentration in the plating pot 301 by increasing or decreasing the aluminum supply amount based on the warning.

  Furthermore, in this Embodiment 2, since the aluminum concentration of the molten zinc bath in the arbitrary cross sections of the plating pot 301 can be visualized, the aluminum concentration distribution can be captured visually. Furthermore, according to the second embodiment, since the aluminum concentration of the molten zinc bath at an arbitrary position of the plating pot 301 can be estimated, the aluminum concentration in the vicinity of the steel plate or sink roll that is difficult to sample is acquired. It becomes possible to do. In addition to the above effects, in the second embodiment, by storing the transmission time as data in advance, after inputting the actual measured concentration of aluminum, in the molten zinc contained in the plating pot 301 in a very short time The concentration distribution of aluminum can be predicted. Therefore, if a technique for measuring the additive metal concentration such as aluminum concentration online in the future is established, it is expected that various additive metal concentrations in the molten zinc bath can be visualized online and utilized for operation management.

  In the present specification, as embodiments, the concentration estimation method, concentration distribution estimation method and concentration monitoring method of substance components taking a water tank and a hot dip galvanizing pot as examples, and the hot dip galvanizing pot accommodated in the hot dip galvanizing pot Although the aluminum concentration management method was demonstrated, this invention is not limited to these.

  As described above, the concentration estimation method, concentration distribution estimation method, concentration monitoring method, aluminum concentration management method in molten zinc accommodated in a hot dip galvanizing pot, and the material in the fluid system in the fluid system of the present invention The component concentration estimation apparatus can be widely used not only for the water tank and hot dip galvanizing pot exemplified in the present specification but also for objects in which the concentration of the substance component in the fluid is important, such as chemical processes and water treatment facilities. In addition, since the fluid temperature can be estimated in addition to the concentration by the same principle, it can be applied to a wide variety of fluid systems such as continuous casting mold and ladle temperature distribution estimation in the steel process.

DESCRIPTION OF SYMBOLS 1 Fluid system 2 Container 3 Partition plate 4 Fluid 100 Water tank 101,102,103 Pipe 104 Partition plate 105 Vertical cross section 106 Electrical conductivity meter 110 Container 200,400 Concentration estimation apparatus 201,401 Input unit 202,402 Display unit 203,403 Storage unit 204, 404 Control unit 205, 405 Concentration estimation unit 206, 406 Concentration data extraction unit 407 Determination unit 300 Hot dip galvanizing pot 301 Plating pot 302 Sink roll 303 Steel plate 304 Ingot

Claims (12)

A method for estimating the concentration of a substance component in a fluid system in which the substance component has a concentration distribution,
At two or more arbitrary concentration measurement points set in the fluid system, the concentration of the substance component is measured by the concentration measuring means arranged at the concentration measurement point, or the concentration of the substance component in the sample collected at the concentration measurement point A concentration measurement step for measuring
At an arbitrary concentration estimation point set in the fluid system, an index relating to the flow field of the fluid system at the concentration estimation point obtained experimentally or by numerical fluid simulation is acquired, and measured by the index and the concentration measurement step An estimation step for estimating a concentration of the substance component at the concentration estimation point based on the concentration of the determined substance component;
Including
The indicator includes a downstream transmission time required for the fluid to move from the concentration measurement point to the concentration estimation point, and an upstream side required for the fluid to move from the concentration estimation point to the concentration measurement point. Transmission time and
The estimation step calculates a weight of the concentration actual measurement point with respect to the concentration estimation point using a weight function that is a monotonous non-increasing function with respect to the downstream transmission time and the upstream transmission time, and measures the weight. A method for estimating a concentration of a substance component in a fluid system, wherein a weighted average with the substance component concentration is estimated as the concentration of the substance component at the concentration estimation point.   The estimation step selects a smaller value of the downstream transmission time and the upstream transmission time as the minimum transmission time when calculating the weight function of the concentration actual measurement point with respect to the concentration estimation point, and the minimum transmission time The weight of the concentration measurement point with respect to the concentration estimation point is calculated using a weight function that is a monotonically non-increasing function, and a weighted average of the weight and the measured substance component concentration is calculated for the substance component at the concentration estimation point. The method for estimating the concentration of a substance component in a fluid system according to claim 1, wherein the concentration is estimated as a concentration. A substance component in a fluid system for estimating the concentration of the substance component in a fluid system in which the supply and / or discharge of the substance component is performed non-stationarily using the method for estimating the concentration of the substance component in the fluid system according to claim 2 A concentration estimation method for
An estimation time designation step for designating a concentration estimation time at the concentration estimation point, and
The concentration measurement step measures the concentration of the substance component at the concentration measurement point in time series,
In the estimation step, a weighted average of the measured concentration and the weight of the concentration measurement point at the extraction time determined based on the concentration estimation time, the downstream transmission time, and the upstream transmission time is calculated as the concentration estimation point. Estimated as the concentration of the substance component in
The extraction time is a monotonic non-increasing function with respect to the downstream transmission time and a monotonic non-decreasing function with respect to the concentration estimation time and the upstream transmission time. Estimation method.   When the downstream transmission time is smaller than the downstream transmission time and the upstream transmission time, the extraction time is defined as a time before the downstream transmission time from the concentration estimation time. 4. The concentration of the substance component at the concentration estimation point is estimated when the transmission time is shorter, with the time after the upstream transmission time from the concentration estimation time as the extraction time. For estimating the concentration of a substance component in a fluid system.   If the concentration of the substance component is not measured at the concentration measurement point in the extraction time, the concentration at the extraction time is interpolated and extrapolated from the measured time-series concentration measurement value as the measured concentration at the extraction time. The concentration at the concentration estimation point is estimated, or the concentration at the concentration estimation point is estimated using the concentration of the substance component measured at a time closest to the extraction time as an actually measured concentration at the extraction time. Item 5. A method for estimating the concentration of a substance component in a fluid system according to Item 4. The fluid system is hot dip zinc in a hot dip galvanizing pot,
In the estimation step, the weight is calculated using the time required for the molten zinc in the hot dip galvanizing pot to move between the concentration measurement point and the concentration estimation point as the index, and is measured in the concentration measurement step. The aluminum concentration in the molten zinc at the concentration estimation point in the hot dip galvanizing pot is estimated using the aluminum concentration in the molten zinc as the substance component concentration, according to any one of claims 1 to 5. For estimating the concentration of a substance component in a fluid system. A method for estimating a concentration distribution of a substance component in a fluid system in which the substance component has a concentration distribution,
Estimating concentrations of substance components at all concentration estimation points set using the method according to any one of claims 1 to 6;
A method for estimating the concentration distribution of a substance component in a fluid system, wherein the concentration distribution of the substance component in the fluid system is obtained by interpolating the actually measured concentration with the estimated concentration. A method for monitoring the concentration of a substance component in a fluid system in which the substance component has a concentration distribution,
8. A substance component in a fluid system, wherein concentration distribution data of an arbitrary cross section is extracted from the concentration distribution data of a substance component in a fluid system obtained by the method according to claim 7, and the extracted concentration distribution data is visualized Concentration monitoring method. A method for controlling the concentration of aluminum in hot dip zinc contained in a hot dip galvanizing pot,
From the aluminum concentration data in the molten zinc in the hot dip galvanizing pot estimated by the method for estimating the concentration of the substance component in the fluid system according to claim 6, the aluminum concentration in the molten zinc in a predetermined region in the fluid system is calculated. A concentration extraction step to extract;
A determination step of determining whether or not the extracted concentration is within a predetermined threshold range;
In the determination step, when it is determined that the concentration is outside the threshold range, a warning step that warns to that effect;
The aluminum concentration control method in the hot dip zinc accommodated in the hot dip galvanization pot characterized by including this. A device for estimating a concentration of a substance component in a fluid system in which the substance component has a concentration distribution,
At two or more arbitrary concentration measurement points set in the fluid system, the concentration of the substance component at the concentration measurement point is measured, or the concentration measurement in the sample collected at the concentration measurement point is measured Means,
Storage means for storing an index relating to the flow field of the fluid system at a concentration estimation point arbitrarily set in the fluid system, obtained by an experimental or numerical fluid simulation;
Concentration estimation means for estimating the concentration of the substance component at the concentration estimation point based on the measured concentration of the target component measured by the concentration measurement means and an index relating to the flow field of the concentration estimation point stored in the storage means When,
With
The indicator includes a downstream transmission time required for the fluid to move from the concentration measurement point to the concentration estimation point, and an upstream side required for the fluid to move from the concentration estimation point to the concentration measurement point. Transmission time and
The estimation step calculates a weight of the concentration actual measurement point with respect to the concentration estimation point using a weight function that is a monotonous non-increasing function with respect to the downstream transmission time and the upstream transmission time, and measures the weight. An apparatus for estimating a concentration of a substance component in a fluid system, wherein the weighted average with the substance component concentration is estimated as the concentration of the substance component at the concentration estimation point. The storage means stores concentration distribution data obtained by interpolating the actual concentration with the concentration of the substance component estimated by the concentration estimation means,
Density data extraction means for extracting density distribution data of an arbitrary cross section from the density distribution data and visualizing the extracted density distribution data;
Display means for displaying concentration distribution data of a substance component of an arbitrary cross section visualized by the concentration data extraction means;
The apparatus for estimating a concentration of a substance component in a fluid system according to claim 10 . The concentration data extracting means extracts the concentration of the substance component in a predetermined region in the fluid system from the concentration distribution data,
Determination means for determining whether or not the extracted concentration is within a predetermined threshold range;
12. The apparatus for estimating a concentration of a substance component in a fluid system according to claim 11 , wherein when the determination unit determines that the concentration is outside a threshold range, the display unit displays a warning to that effect.

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