JP3206673B2 - Automatic control device for ozone generation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a water treatment apparatus for performing water treatment using ozone, and automatically controls the amount of ozone generated by an ozone generator according to a change in a substance to be treated. It relates to an automatic generation amount control device.

[0002]

2. Description of the Related Art An apparatus of this kind, which controls the amount of ozone generated by feeding back either the concentration of exhausted ozone or the concentration of dissolved ozone, is already known. The relationship between the amount of the substance to be treated in the source water (hereinafter referred to as the pollution load), the amount of injected ozone, the amount of ozone discharged, and the amount of dissolved ozone in the treated water will be described. Reacts with target substances and self-decomposes,
The remainder is discharged as exhausted ozone and dissolved ozone contained in the exhaust gas and the treated water. If the amount of injected ozone is fixed to a fixed amount, the amount of injected ozone will be insufficient to obtain the expected treatment effect when the pollution load increases. The ozone injection amount (ozone generation amount) is controlled so that either of them becomes constant.

However, the purpose of water treatment is to change the substance to be treated in the water to be treated, and the concentration of ozone discharged and the concentration of dissolved ozone have some correlation with the change in the substance to be treated. Therefore, since it is used for control as a surrogate index of the change of the substance to be treated, it is satisfactory even if only one of the exhausted ozone concentration and the dissolved ozone concentration is used as the surrogate index of the change of the substance to be treated. There is no control result to be obtained.

Therefore, the larger of the measured value of the ozone discharged from the reaction tank and the measured value of the dissolved ozone in the treated water flowing out of the reaction tank is selected, and the selected measured value is set in advance. (Hereinafter referred to as “conventional device”) is disclosed in
No. 0499. As shown in FIG. 9, this conventional apparatus 20 measures the concentration of exhaust ozone in exhaust gas C discharged from an ozone reactor 1 that takes in raw water (water to be treated) A and performs ozone treatment. And a dissolved ozone concentration measuring device 3 for measuring the dissolved ozone concentration in the treated water B flowing out of the reaction tank 1. The output of the measuring devices 2 and 3 is compared in a comparison arithmetic unit 4. The ozone generation amount is controlled by selecting the larger value and outputting it to the controller 5 that controls the power supply 7 of the ozone generator 6. In short, the conventional device 2
Numeral 0 designates a system for controlling the concentration of exhausted ozone, which is mainly composed of the measuring device 2 and the controller 5, and a system for controlling the concentration of dissolved ozone, which is mainly composed of the measuring device 3 and the controller 5. The control systems for ozone and dissolved ozone are both cascade control systems having a constant concentration.

[0005]

According to the above-mentioned known technique, when the amount of injected ozone is large and the amount discharged as dissolved ozone is neglected, the constant control of the concentration of discharged ozone is carried out. When too much dissolved ozone in the treated water at the tank outlet affects the subsequent process, constant control of the dissolved ozone concentration has been often used. However, in the case of this dissolved ozone concentration constant control, the dissolved ozone is not only the amount of the substance to be treated, but also the difference in the solubility of ozone depending on the temperature,
Influenced by the difference in the rate of self-decomposition of ozone depending on pH and temperature, etc., and even though the treatment reaction of the target substance is sufficiently performed, the excess ozone is injected because the dissolved ozone concentration does not increase. In addition, in the case of constant control of the concentration of exhausted ozone, the dissolved ozone becomes excessive due to the high solubility of ozone, which may adversely affect a subsequent process.

FIG. 10 shows the relationship between the ozone injection rate (the amount of ozone injected at certain time intervals) and the exhausted ozone concentration, and FIG. 11 shows the relationship between the ozone injection rate and the dissolved ozone concentration for different pollutant loads. The balance of ozone is as described below. Injected ozone = (dissolved ozone) + (discharged ozone) = (reaction consumed ozone + self-decomposition ozone + dissolved ozone) + (discharged ozone) Reaction consumed ozone = (ozone consumed for treatment of target substances (improvement of water quality)) ) + (Ozone consumed by reaction with other substances)

From FIGS. 10 and 11, when the amount of ozone generated is controlled by the above-mentioned conventional apparatus, it can be said that when the pollution load is large, the dissolved ozone concentration constant control is continued.
The amount of injected ozone is large. However, even if the dissolved ozone concentration is zero, as long as the ozone is injected, the ozone treatment proceeds, and the quality of the treated water B is improved. In addition, in the case of the exhaust ozone concentration constant control, the exhaust ozone includes not only surplus ozone used for improving water quality but also ozone discharged without being involved in water treatment at all. It is necessary to set the target value of the exhausted ozone concentration to a high level, and as a result, when the pollution load is small, more ozone is injected than necessary. In short, in the conventional apparatus, the ozone injection tends to be excessively large because the water quality is promptly and surely improved.

The present invention has been made in view of the above points, and is suitable for performing ozone treatment of a substance to be treated without excessively injecting ozone and improving the quality of treated water. An object of the present invention is to provide an automatic generation amount control device and to improve the ozone generation amount control accuracy of such an automatic ozone generation amount control device.

[0009]

In order to achieve the above object, in the first invention of the present application, an ozone generator (6) is provided.
Ozone concentration measuring device for measuring the concentration of exhausted ozone discharged from an ozone reaction tank (1) in which ozone generated in the above is injected and the target substance in the incoming raw water is changed and the raw water is discharged as treated water. (2) The control calculation is performed based on the exhaust ozone concentration measurement value (PVH) output from the exhaust ozone concentration measuring device and the target value of the exhaust ozone concentration (SVH), and the exhaust ozone concentration control signal (ΔMVH) is obtained. An output ozone concentration controller (31) for outputting, a dissolved ozone concentration measuring device (13) for measuring the concentration of dissolved ozone in the treated water flowing out of the ozone reaction tank, and a dissolved ozone output from the dissolved ozone concentration measuring device A dissolved ozone concentration controller (32) that performs a control operation based on the concentration measurement value (PVH) and the dissolved ozone concentration target value (SVN) and outputs a dissolved ozone concentration control signal (ΔMVN) ), The control unit performs a control calculation based on the output of the ozone generation amount measuring device (8) for measuring the ozone generation amount of the ozone generation device (6). An ozone generation amount controller (38) for outputting an ozone generation amount control signal (MV) for controlling the ozone generation amount, and a first adder (33) for adding the ozone generation amount control signal and the exhausted ozone concentration control signal. A first multiplier (35) for multiplying the addition result of the first adder by a predetermined first coefficient (k ₂ ); and a second multiplier for adding the ozone generation amount control signal and the dissolved ozone concentration control signal. A second adder (34); a second multiplier (36) for multiplying the addition result of the second adder by a predetermined second coefficient (k ₁ );
A third output for adding the output of the multiplier and the output of the second multiplier and outputting the result to the ozone generation amount controller as a target value of the ozone generation amount.
And an adder (37).

Further, in the second invention of the present application, the ozone generation amount automatic control device is based on the output (PV) of the ozone generation amount measuring device (8) for measuring the ozone generation amount of the ozone generation device (6). Control signal (MV) for performing control calculations to control the amount of ozone generated by the ozone generator.
And a plurality of exhaust ozone concentration measurement values sampled in a control cycle of the ozone generation amount by the ozone generation amount controller. (47) for calculating a predicted value of the exhausted ozone concentration in the exhaust gas, a predicted value of the exhausted ozone concentration (PVHY) output from the predicted value of the exhausted ozone concentration (PVHY), and a target value of the exhausted ozone concentration (SVH). ), An exhaust ozone concentration prediction correction term calculator (41) for outputting an exhaust ozone concentration correction control signal (ΔMVHY), an exhaust ozone concentration control signal (ΔMVH), and an exhaust ozone concentration correction control signal. And a first adder (4
3), a first converter (45) for converting the addition result of the first adder into a position-type control signal, and a first converter for multiplying the output of the first converter by a predetermined first coefficient. Multiplier (3
5) and calculating a predicted value of the dissolved ozone concentration at the time when the next control cycle is reached, based on the plurality of measured dissolved ozone concentrations sampled in the ozone generation amount control cycle by the ozone generation amount controller. A control operation is performed based on a dissolved ozone concentration predicted value calculator (48), a dissolved ozone concentration predicted value (PVNY) output from the dissolved ozone concentration predicted value calculator and a dissolved ozone concentration target value (SVN), A dissolved ozone concentration prediction correction term calculator that outputs a dissolved ozone concentration correction control signal (ΔMVNY), a second adder (44) that adds the dissolved ozone concentration control signal (ΔMVN) and the dissolved ozone concentration correction control signal, A second converter (46) for converting the addition result of the second adder into a position-type control signal, and a second converter for multiplying the output of the second converter by a predetermined second coefficient. A third addition unit that adds the output of the first multiplier and the output of the second multiplier to the adder (36) and outputs the result to the ozone generation amount controller (38) as a target value (SV) of the ozone generation amount Vessel (37).

[0011]

According to the first technical means of the present invention, the control of the exhausted ozone concentration and the control of the dissolved ozone concentration are simultaneously performed with respect to the control of the ozone generation amount. The excessive generation of ozone, which tends to occur when the pollution load during constant control is large,
Deter.

According to the second aspect of the present invention, predicted values of the exhausted ozone concentration and the dissolved ozone concentration at the time when the next control cycle of the ozone generation amount is reached are taken into the exhausted ozone concentration control and the dissolved ozone concentration control. The difference in the control delay time (so-called dead time) between the exhaust ozone concentration control and the dissolved ozone concentration control is eliminated, and the control output hunting is suppressed while the ozone generation amount control cycle is set short to avoid the control delay. .

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The same parts as those in FIG. 9 describing the conventional device are denoted by the same reference numerals, and the description thereof will be omitted. FIG. 1 is a schematic explanatory diagram of a first embodiment of the present invention. As shown in the figure, the ozone generation amount control apparatus according to the present embodiment receives as input the exhaust ozone concentration PVH and the target value SVH of the exhaust ozone concentration measured by the exhaust ozone concentration measuring device 2, and according to the deviation of these inputs. A control operation (PID operation or PI operation) is performed, and an exhaust ozone concentration primary controller 31 that outputs an operation output ΔMVH, and a dissolved ozone concentration PV measured by the dissolved ozone concentration measuring device 3
N and a target value SVN of dissolved ozone concentration as inputs, perform a control calculation (PID calculation or PI calculation) according to the deviation of these inputs, and provide a dissolved ozone concentration primary regulator 32 that outputs a calculation output ΔMVN. I have. The output ΔMVH of the exhaust ozone concentration primary controller 31 is calculated by the adder 33 and the multiplier 35.
, The output ΔMVN of the dissolved ozone concentration primary controller 32
Are input to an adder 37 via an adder 34 and a multiplier 36, and are added. The adder 37 calculates the sum SV
Is the ozone generation amount controller as the target value of the ozone generation amount.
Output to

The ozone generation amount controller 38 receives the ozone generation amount PV measured by the ozone generation amount measuring device 8 provided in the ozone generator 6 and the ozone generation amount target value SV output from the adder 37 as inputs. A secondary control calculation (PID calculation or PI calculation) is performed based on the difference between the ozone generation amount PV and the ozone generation amount target value SV, and the power set value MV is output to the power supply 7 of the ozone generator 6, Thus, the amount of ozone generated in the ozone generator 6 is controlled.

The previous value of the power set value MV is output from the ozone generation amount controller 38 to the adders 33 and 34. The previous value of the power set value MV is added by the adder 33 to the present value of the output ΔMVH of the exhaust ozone concentration primary regulator 31. Therefore, the output MVH of the adder 33 is M
VH = ΔMVH (current value) + MV (previous value). The multiplier 35 multiplies the input output MVH of the adder 33 by a constant k ₂ and outputs the result of the multiplication to the adder 38.
Further, the previous value of the power set value MV is added to the current value of the output ΔMVN of the dissolved ozone concentration primary regulator 32 in the adder 34. Therefore, the output MVN of the adder 34 is M
VN = ΔMVN (current value) + MV (previous value). The multiplier 36 multiplies the input output MVH of the primary adjuster 34 by a constant k ₁ and outputs the result of the multiplication to the adder 37. Accordingly, the addition result SV output from the adder 37 to the ozone generation amount controller 38 as the target value of the ozone generation amount is:
SV = (k ₁ ) × (MVN) + (k ₂ ) × (MVH), whereby it becomes possible to control the amount of ozone generation using the output of each control concentration of the exhausted ozone concentration and the dissolved ozone concentration.

In order to prevent the output ΔMVH and ΔMVN of each of the primary regulators of the exhaust ozone and the dissolved ozone concentration from being saturated in the positive or negative direction, each primary controller 3
1 and 32 are speed type regulators whose outputs are ΔMV, and the previous output value of the ozone generation amount regulator 38 as a secondary regulator is integrated with the output of the speed type regulator to obtain MVN and MVH. I am trying to get it.

FIG. 2 shows a temporal change of each ozone concentration controlled by the above-described first embodiment. The figure shows that the measured value (actual value) PVN of the dissolved ozone concentration and the deviation DVN between the target value SVN and the measured value (actual value) PVH of the exhausted ozone concentration and the deviation DVH of the target value SVH are balanced, and the ozone generation amount is reduced. This is a schematic diagram showing a stable case.
The constants k ₁ and k ₂ may be determined empirically so that DVN and DVH are balanced.

By setting the constants k ₁ and k ₂ to appropriately determine the share ratio between the exhaust ozone concentration control and the dissolved ozone concentration control, if the pollutant load during the constant exhaust ozone concentration control is small, And when the pollutant load at the time of the dissolved ozone constant control is large, an excessive amount of ozone, which tends to occur when the pollutant load is large, can be monitored without monitoring the pollutant load and switching between the exhaust ozone concentration constant control and the dissolved ozone constant control.
Therefore, the ozone generation amount can be easily controlled without depending on the complicated operation.

In the first embodiment, the time from when ozone is generated until the ozone is detected as dissolved ozone and exhausted ozone, that is, what is called a dead time or delay time of ozone generation control ( Hereinafter, the dead time will be as shown in Table 1 on the next page.

As shown in Table 1 below, there is a non-negligible time difference between the detection of ozone concentration and the detection of dissolved ozone concentration after ozone generation. In the device of the first embodiment,
One method of taking the time difference in advance and controlling the ozone generation amount is to prevent the divergence of the control output from occurring.
Considering the above dead time, set a longer control cycle,
The control is performed for each control cycle. However, as the control cycle is lengthened, the delay of the control response increases, and it becomes impossible to follow a change in the water treatment situation. Further, if the control cycle is set to be short ignoring the dead time, the control output will diverge, and the output becomes zero.
Hunting may occur between 100% and 100%.

[0021]

[Table 1]

Therefore, in the second embodiment of the present invention, a plurality of measured values of the exhausted ozone concentration and the dissolved ozone concentration are sampled by the apparatus of the first embodiment in a control cycle.
Based on the sampling data, an approximate straight line is formed using the least squares method, and when the ozone generation amount control time is reached, a means for predicting the ozone concentration at the time when the next control time is reached and correcting the control output value this time is added. Accordingly, the previous value of the output MV of the ozone generation amount controller 38 is not added to the outputs of the primary controllers 31 and 32.

FIG. 3 is a schematic block diagram of a second embodiment of the present invention. Note that, in FIG. 3, the same portions and portions having the same functions as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. 3 differs from the first embodiment shown in FIG. 1 in that the exhaust ozone concentration control system and the dissolved ozone concentration control system have prediction correction term calculators 41 and 42, output converters 45 and 46, and a prediction calculator, respectively. 47 and 48 are added, and the adders 33 and 34 are eliminated.

The configuration of the prediction correction term calculators 41 and 42 is exactly the same except that their inputs and outputs are different, and the other functions are exactly the same. Therefore, the prediction correction term calculator 42 of the dissolved ozone concentration control system has a more detailed structure. FIG. 4 shows an example of the structure of a primary part of the dissolved ozone concentration control system together with the primary controller 32 and the like. In the figure, a dissolved ozone concentration primary regulator 32 receives a measured value PVN of dissolved ozone concentration and a target value SVN. The difference between the input measured value PVN and the target value SVN is compared by a subtractor 60 built in the controller 32, and the output of the subtractor 60 is compared with the dead zone element 61.
The deviation output DVN obtained through the above is input to the control calculator 62 (in the figure, a PI calculator) to obtain a control output ΔMVN.

The target value SVN of the dissolved ozone concentration and the predicted value PVNY of the dissolved ozone concentration output from the dissolved ozone concentration predicting calculator 48, which will be described later, are input to the prediction correction term calculator 42 of FIG. Value PVNY and target value S
The deviation of VN is determined by a built-in subtractor 63,
Output DVNY obtained through the dead zone element 64
Is input to the control computing unit 65 (the PI computing unit in the figure) to obtain another control output ΔMVNY. Then, the two control outputs .DELTA.MVN and .DELTA.MVNY are added by the adder 44, and the sign of the addition result is judged by the sign judgment unit 66 of the output converter 46, integrated by the integrator 67, and this integration result is limited by the limiter 6
8 and the control operation output MVN is obtained through the dead zone element 69. This MVN corresponds to the output of the adder 34 in the first embodiment shown in FIG. The function of the output converter 46 is to convert the speed-type control output ΔMVN + ΔMVNY into a position-type control operation output MVN.

The controller 31 of the exhaust ozone concentration control system,
Prediction correction term calculator 41, adder 43, and output converter 4
5, the target value SVN is changed to SVH, and the measured value PVN
To PVH, the predicted value PVNY to PVHY, and both control outputs ΔMVN and ΔMVNY to ΔMVH and ΔMVHY, respectively.
Should be read as

Returning to FIG. 3, the output MV of the output converter 45
Type H to the multiplier 35, multiplied by a predetermined constant k _2, inputs the output MVH output transducer 46 to the multiplier 35, multiplied by a predetermined constant k _1, thus obtained (k ₂₎ × (MV
H) and the sum (k ₁ ) × (MVN) in the adder 37 in the adder 37 (k ₁ ) × (MVN) + (k ₂ ) × (MVH) is used as the target value SV of the ozone generation amount and the ozone generation amount controller. 3
8 is the same as in the first embodiment.

FIG. 5 is a diagram for explaining the change over time of the ozone concentration controlled by the apparatus of the second embodiment. The figure shows
It is described using dissolved ozone concentration as an example.
Although the control deviation in _N is PVN-the SVN, when maintaining the control output as is, dissolved ozone concentration at time X _E of After one control period T _C is the straight line (b) PVN
It becomes Y. Also, the control deviation PVN at the current time T _N
When control is performed by -SVN, the dissolved ozone concentration changes along the curve (b). Therefore, when applying a correction by deviations PVNY-SVN predicted value at time X _E, dissolved ozone concentration becomes vary along the curve (c), the control system is improved.

Next, a description will be given of the prediction calculation in the prediction calculators 47 and 48. The prediction calculators 47 and 48 are composed of, for example, microcomputers, count clock pulses of a built-in clock thereof, measure the ozone concentration, for example, the dissolved ozone concentration a plurality of times at every predetermined count, and sample the measured values. Bring the average value. Time T _1, T 2 during the operation of the control time T _{C, ─,}
The operation is performed N times at T _N (where T _N = T _C ) to obtain the average values G ₁ , G _2, ,, _and G _N of the _N ozone concentrations. Then, when the control time T _C has elapsed, the sampling times T ₁ , T _2,
─, T _N and measurements G _1, G 2, ─, from G _N, calculates the Shoshiki described below including the total value Y of the total value X and the measurement value of the time.

X = T ₁ + T ₂ + ΔT _N (1)

Y = G ₁ + G ₂ + ΔG _N (2)

[0032] _{XY = T 1 G 1 + T} 2 G 2 + ─T N G N (3)

[0033] ^{_{XX = T 1 2 + T 2}} 2 + ─T N 2 (4)

B = (N ・ XY-XY ・) / (N ・ XX-X ² ) (5)

A = (Y / N) −b (X / N) (6)

Further, the equation (7) is calculated using the coefficient b and the constant a obtained from the equations (5) and (6).

Y _E = bX _E + a (7)

The above is the well-known least-squares prediction calculation method. Y _E obtained by the above equation (7) is the predicted value of the measured value Y at time X _E after time T _C. Therefore, when calculating the predicted value PVNY of the dissolved ozone concentration at the time when the next control cycle is reached, the following equation (8) is used.

PVNY = b _PVN X _E + a _PVN (8)

When the predicted value PVHY of the exhaust ozone concentration at the time when the next control cycle is reached is obtained, the following equation (9) is used.

PVHY = b _PVH X _E + a _PVH (9)

Next, the above predicted values PVHY and PVN
The operation of the prediction calculator 47 to obtain the Y, is described by the flow chart of the diagram and FIG. 8 illustrating the equation (7) for obtaining an operation explanatory diagram of Figure 6, the predicted value Y _E of the ozone concentration in FIG. The following description is common to both the exhaust ozone concentration and the dissolved ozone concentration. At the sampling time T _n (at the time of the n-th sampling), the ozone concentration is measured a plurality of times, and the measured value is stored in the measured value storage file (measured value storage FL) of the predictive computing unit. The plurality of measurements may be a plurality of measurements using one ozone concentration measuring device or a measurement using a plurality of ozone concentration measuring devices. Store a predetermined number of measured values in measured value FL
Is stored in the measured value storage FL.
Is taken out to the working area of the prediction computing unit, and the average value _Gn of the measured values is calculated, stored in the average value storage file (average value storage FL), and the contents of the measured value storage FL are cleared to zero. Similarly, every time the sampling time comes, the average value of the measured ozone concentration is calculated and sequentially stored in the average value storage FL. Each time the average value of the ozone concentration is calculated,
Sequentially stores data of the sampling time T _n on the average time storage file, not shown (mean time storage FL). In this way, when the control cycle _Tc has elapsed ( _Tn = _TN = _Tc )
Then, the average value data of the predetermined number N of ozone concentrations is stored in the average value storage FL. N average value data G _{1 to} G _N
Is stored in the average value storage FL, and these average value data are sequentially taken out to the working area of the predictive computing unit, and the data shown in FIG.
According to the steps described in the flowchart of equation (1),
(7) is performed.

In FIG. 8, the control cycle time measurement is started in step 1, and it is assumed that one control cycle has elapsed in step 2, and in step 3, X, Y,
The values of XY, XX and T are set to 0. Next, the process proceeds to step 4, where the number of stored average value data stored in the average value storage FL is calculated. In step 5, the oldest block data stored in the average value storage FL is moved to the working area, and the pointer is set. Advance one step. The same processing as in step 5 is performed for the average time storage FL (step 6). The content of the average time storage FL is data T ₁ , T ₂ , and ΔT _N of the moving average time (sampling time T _n ) shown in FIG. Subsequently, in step 7, using the data of the average value and the moving average time read in steps 5 and 6, X, Y, XY, XX
And various quantities of T, and then in step 8,
Read the pointer of step 5 or 6 and read step 7
It is determined whether or not the calculation of the various quantities has been performed for all of the data storage number of the average value or the moving average time. If the calculation has not been performed for all of the stored data, the process returns to step 5; Then, the coefficient b and the constant a are calculated by the equations (5) and (6). Then, the predicted value Y _E of the measured value at the next control cycle arrival time X _E (see FIG. 7) is calculated in step 10 using the coefficient b and the constant a obtained by this calculation. Next, in step 11, the contents of the average value storage FL and the average time storage FL are cleared to return to the initial state.

According to the second embodiment, for example, the control cycle of the first embodiment in which the prediction calculation of the ozone concentration is not performed is 15 minutes, but the control cycle is reduced to 7 minutes, which is half of the control cycle. Does not cause hunting of the control output.

[0045]

As described above, according to the first aspect of the present invention, the control of the exhausted ozone concentration and the control of the dissolved ozone concentration are simultaneously performed for the control of the ozone generation amount, and the pollution load at the time of the exhaust ozone concentration constant control is controlled. Is small, and when the pollutant load during the constant control of dissolved ozone is large, it is possible to suppress the excessive generation of ozone, which tends to occur.

According to the second aspect of the present invention, in addition to the effects of the first aspect, the exhaust ozone concentration control and the dissolved ozone concentration control are performed at the time when the next control cycle of the ozone generation amount is reached. By incorporating the predicted values of the ozone concentration and the dissolved ozone concentration, the difference in the control delay time (so-called dead time) between the exhaust ozone concentration control and the dissolved ozone concentration control is eliminated,
The hunting of the control output can be suppressed while the control cycle of the ozone generation amount is set short to avoid the control delay, and the control accuracy of the ozone generation amount is further improved.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of an automatic ozone generation amount control apparatus according to the present invention.
Schematic configuration diagram of the embodiment

FIG. 2 is a diagram showing a temporal transition of each ozone concentration controlled by the first embodiment apparatus.

FIG. 3 shows a second embodiment of the automatic ozone generation amount control apparatus according to the present invention.
Schematic configuration diagram of the embodiment

FIG. 4 is a configuration diagram of a main part of a second embodiment apparatus.

FIG. 5 is a diagram illustrating a temporal change of an ozone concentration controlled by the second embodiment apparatus.

FIG. 6 is an explanatory diagram of the operation of the prediction arithmetic unit.

FIG. 7 is a diagram for explaining an equation (7) for obtaining a predicted value of the ozone concentration.

FIG. 8 is a flowchart for calculating a predicted value of an ozone concentration.

FIG. 9 is a schematic configuration diagram of a conventional technology of an automatic ozone concentration control device.

FIG. 10 is a diagram for explaining a relationship between an exhausted ozone concentration and an ozone injection rate.

FIG. 11 is a diagram for explaining a relationship between a dissolved ozone concentration and an ozone injection rate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ozone reaction tank 2 Discharged ozone concentration measuring device 3 Dissolved ozone concentration measuring device 6 Ozone generator 7 Ozone generation power supply 8 Ozone generation amount meter 31 Discharged ozone concentration primary regulator 32 Dissolved ozone concentration primary regulator 33 Adder 34 Adder 35 Multiplier 36 Multiplier 37 Adder 38 Ozone generation amount controller 41 Prediction correction term calculator 42 Prediction correction term calculator 43 Adder 44 Adder 45 Output converter 46 Output converter 47 Exhaust ozone concentration prediction calculator 48 Dissolved Ozone concentration prediction calculator 60 Subtractor 61 Dead zone element 62 Control calculator 63 Comparator 64 Subtraction zone element 65 Control calculator 66 Sign determiner 67 Integrator 68 Limiter 69 Dead zone element A Raw water B Treated water C Exhaust gas PV Ozone generation SV Ozone generation target value MV Power setting value PVH exhaust ozone concentration SVH exhaust ozone concentration Standard value PVN dissolved ozone concentration SVN dissolved ozone concentration target value PVHY exhausted ozone concentration predicted value PVNY dissolved ozone concentration predicted value T _c control cycle T _n sampling time G _n average value of ozone concentration measured value X _E arrival time of next control cycle Y _E Ozone concentration prediction calculation value

Continuation of front page (56) References JP-A-63-90499 (JP, A) JP-A-59-39388 (JP, A) JP-A-56-14403 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) C02F 1/78 C02F 1/50

Claims (2)

(57) [Claims] An ozone generated by an ozone generator is injected, and a concentration of exhausted ozone discharged from an ozone reaction tank that changes a substance to be treated in the raw water flowing in and discharges the raw water as treated water is measured. An exhaust ozone concentration measuring device, and a control operation is performed based on the exhaust ozone concentration measurement value output from the exhaust ozone concentration measuring device and a target value of the exhaust ozone concentration,
An exhaust ozone concentration controller that outputs an exhaust ozone concentration control signal; a dissolved ozone concentration measuring device that measures the concentration of dissolved ozone in the treated water flowing out of the ozone reaction tank; and a dissolved ozone output by the dissolved ozone concentration measuring device. A dissolved ozone concentration controller that performs a control operation based on the concentration measurement value and the target value of the dissolved ozone concentration and outputs a dissolved ozone concentration control signal, and an ozone generation amount automatic control device comprising: An ozone generation amount controller for performing a control operation based on an output of an ozone generation amount measuring device for measuring an ozone generation amount and outputting an ozone generation amount control signal for controlling the ozone generation amount of the ozone generation device; A first adder for adding the amount control signal and the exhausted ozone concentration control signal; and a first adder for multiplying the addition result of the first adder by a predetermined first coefficient. A second adder that adds the ozone generation amount control signal and the dissolved ozone concentration control signal; a second multiplier that multiplies the addition result of the second adder by a predetermined second coefficient And a third adder that adds the output of the first multiplier and the output of the second multiplier and outputs the result to the ozone generation amount controller as a target value of the ozone generation amount. An automatic ozone generation control device. 2. The concentration of waste ozone discharged from an ozone reaction tank into which ozone generated by an ozone generator is injected, the target substance in the raw water flowing in is changed, and the raw water is discharged as treated water. An exhaust ozone concentration measuring device, and a control operation is performed based on the exhaust ozone concentration measurement value output from the exhaust ozone concentration measuring device and a target value of the exhaust ozone concentration,
An exhaust ozone concentration controller that outputs an exhaust ozone concentration control signal; a dissolved ozone concentration measuring device that measures the concentration of dissolved ozone in the treated water flowing out of the ozone reaction tank; and a dissolved ozone output by the dissolved ozone concentration measuring device. A dissolved ozone concentration controller that performs a control operation based on the concentration measurement value and the target value of the dissolved ozone concentration and outputs a dissolved ozone concentration control signal, and an ozone generation amount automatic control device comprising: An ozone generation amount controller for performing a control operation based on the output of the ozone generation amount measuring device for measuring the ozone generation amount and outputting an ozone generation amount control signal for controlling the ozone generation amount of the ozone generator; When the next control cycle is reached, based on a plurality of measured exhaust ozone concentration values sampled during the control cycle of the amount of ozone generated by the quantity controller An exhaust ozone concentration predicted value calculator for calculating a predicted value of the exhaust ozone concentration in the above, and a control calculation based on the exhaust ozone concentration predicted value output from the exhaust ozone concentration predicted value calculator and the target value of the exhaust ozone concentration. An ozone concentration estimation / correction term calculator for outputting an ozone concentration correction control signal; a first adder for adding the ozone concentration control signal to the ozone concentration correction control signal; A first converter for converting the addition result of the converter into a position-type control signal; a first multiplier for multiplying an output of the first converter by a predetermined first coefficient; A dissolved ozone concentration predicted value calculator that calculates a predicted value of the dissolved ozone concentration at the time when the next control period is reached, based on a plurality of dissolved ozone concentration measured values sampled in the control cycle of the ozone generation amount by A dissolved ozone concentration prediction correction term calculator that performs control calculation based on the dissolved ozone concentration prediction value output from the dissolved ozone concentration prediction value calculator and the target value of the dissolved ozone concentration and outputs a dissolved ozone concentration correction control signal A second adder for adding the dissolved ozone concentration control signal and the dissolved ozone concentration correction control signal; and a second converter for converting the addition result of the second adder into a position-type control signal. A second multiplier for multiplying the output of the second converter by a predetermined second coefficient; and adding the output of the first multiplier and the output of the second multiplier to obtain an ozone generation amount. A third adder that outputs a target value to the ozone generation amount controller, and an ozone generation amount automatic control device.