JPH0830661B2 - Discharge water amount measuring device and discharge water amount measuring method of preceding standby type pump - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge water amount measuring device for measuring the discharge water amount of a preceding standby type pump which is operated at full speed from a water level at which air is suctioned and mixed below a normal pump operating water level. The present invention relates to a discharged water amount measuring method.

[0002]

2. Description of the Related Art In recent years, the improvement of pavement rate due to urbanization and residential development in urban areas, and the spread of sewer pipes,
Rainwater tends to flow into the pump equipment rapidly and in large quantities. However, it is economically difficult to install a water absorption tank having a sufficient capacity for the inflow of a large amount of rainwater because the land is expensive. Therefore, the capacity of the water absorption tank is not sufficient, and the water level is likely to change drastically. In order to cope with this rapid change in the water level, a preliminary standby operation in which the inflow of rainwater is predicted and the pump is in a full-speed operation state in advance has been attempted.

In the preceding standby operation, the full-speed operation is performed below the normal pump operating water level, so that the air-water mixed operation state and the air operation state are generated. Therefore, as an attempt to reduce abnormal vibration and noise in the air-water mixed operation state, as shown in FIG. 11, the intake pipe 1 communicating with the atmosphere is
It is proposed that 0 is opened to the impeller casing 16 or the suction bell mouth 18 below the impeller 14 of the vertical pump 12. In addition, in FIG. 11, 20 is a suction water tank.

In the preceding standby type pump shown in FIG. 11, air is naturally sucked into the vertical pump 12 through the intake pipe 10 by the negative pressure generated at the inlet of the impeller 14, so that abnormal vibration and noise are generated. The occurrence of is reduced.

By the way, in the preceding standby type pump shown in FIG. 11, the sucked air is mixed with the discharge flow rate, and the discharge water amount obtained by subtracting the mixed air amount from the discharge flow amount is accurate. Difficult to measure. If this is a conventional pump that operates without being mixed with air, obtain a single pump performance characteristic curve of the total pump head and discharge water amount in advance, and measure the actual pump head and the pipe system resistance. The amount of discharged water can be easily calculated from the pipeline resistance curve obtained from the value and the previous pump performance characteristic curve. However, in the preceding standby pump, the performance is represented by a group of characteristic curves of the actual head and the discharge flow rate (air amount + discharge water amount), with the mixture ratio of the air amount and the discharge water amount as a parameter. The amount of water discharged cannot be calculated from the measured values of the head only.

Therefore, the inventors of the present invention have found that the amount of discharged water is calculated by using the air amount and the actual pump head from the pump performance characteristic curve group of the actual pumping head and the discharge flow amount with the mixture ratio of the air amount and the discharged water amount as a parameter. Based on the finding that it can be obtained, Japanese Patent Application No. 2-22
No. 5229, as shown in FIG. 12, an air amount measuring means 30 for measuring the amount of air sucked into the intake pipe 10 is provided, and a suction water tank water level measuring means 34 for measuring the water level of the suction water tank 20 is provided to discharge the air. Discharge water tank water level measuring means 36 for measuring the water level of the sewage water tank 28 is provided, and signals corresponding to the air amount output from the air amount measuring means 30 and output from the suction and discharge water tank water level measuring means 34 and 36, respectively. From the signal according to the water level and the discharge flow rate of the vertical pump 12 and the pump performance characteristic curve group of the actual pump head which are measured in advance using the mixing ratio of the amount of air mixed with the discharge flow rate as a parameter, We proposed a technology to calculate the amount of water discharged. In FIG. 12, 22 is a butterfly valve, 24 is a telescopic tube, 26 is a gradually expanding tube, and 38 is a display means.

[0007]

First, Japanese Patent Application No. 2-22
The technology proposed in No. 5229 is extremely useful in practice because the discharge water amount of the vertical pump 12 can be easily and accurately determined at the site where the pump is installed even in the air-water mixing operation range. is there.

Here, the air amount measuring means 30 for measuring the air sucked into the vertical shaft pump 12 from the intake pipe 10 heats the platinum wire, for example, by applying a predetermined current to the platinum wire to heat it. Since it is cooled by cooling, an extremely precise measuring device such as measuring the temperature of the platinum wire to measure the amount of air is used. Therefore, the installation and maintenance of the air amount measuring means 30 is troublesome.

According to the present invention, there is provided a discharge water amount measuring apparatus for a preceding standby type pump, wherein the discharge water amount is accurately calculated from the opening water level of the intake pipe and the actual head without using the air amount measuring means. It is intended to provide a method for measuring water content.

[0010]

In order to achieve the above object, the discharge water amount measuring apparatus of the preceding standby type pump of the present invention is arranged so that the impeller casing below the impeller of the vertical shaft pump or the suction bell mouth is exposed to the atmosphere. Open the communicating intake pipe,
Provided with a suction water tank water level measuring means for measuring the water level of the suction water tank, provided with a discharge water tank water level measuring means for measuring the water level of the discharge water tank, calculated from the signals respectively output from the suction and discharge water tank water level measuring means A pump performance characteristic curve group of the vertical shaft pump measured in advance using a value corresponding to the opening water level and actual head of the intake pipe, and the opening water level of the intake pipe, and the vertical pump pump system resistance measured in advance. The amount of water discharged is calculated by the calculating means from the value.

Then, instead of the pump performance characteristic curve group measured in advance using a value corresponding to the opening water level of the intake pipe as a parameter, the opening water level of the intake pipe is changed and measured in advance using the pipe system resistance value as a parameter. The discharge means may calculate the discharge water quantity using the relational expression group of the discharge water quantity and the total head of the vertical shaft pump.

Further, the method for measuring the discharge water amount of the preceding standby type pump according to the present invention is such that the blades below the impeller of the vertical shaft pump are output from the signal output from the suction water tank water level measuring means or the water pressure measuring means arranged in the suction water tank. Calculate the opening water level of the intake pipe that opens to the car casing or the suction bell mouth in communication with the atmosphere, and use the multiple values corresponding to the opening water level of this intake pipe as parameters to measure the discharge water amount of the vertical pump and the total amount. Select the relational expression of the pump performance characteristic curve with the value of the opening water level of the intake pipe calculated from the pump performance characteristic curve group of the head as a parameter, and use the suction water tank water level measuring means or the water pressure measuring means arranged in the suction water tank. Actual head from the signal output and the signal output from the discharge water tank water level measuring means or the water pressure measuring means or discharge pressure measuring means arranged in the discharge water tank Then, the relational expression of the pipeline resistance curve is calculated from this actual head and the set pipe system resistance value, and the intersection of the relational expression of the pump performance characteristic curve and the relational expression of the pipeline resistance curve is calculated by the Newton-Raphson method. To calculate the discharge water amount discharged from the vertical shaft pump.

Then, instead of the pump performance characteristic curve group measured in advance using a plurality of values corresponding to the opening water level of the intake pipe as parameters, the opening water level of the intake pipe is changed using a plurality of pipe system resistance values as parameters. Then, the discharge water amount is calculated by selecting the relational expression of the pump performance characteristic curve with the value of the opening water level of the intake pipe calculated above as a parameter from the relational expression group of the discharge water amount and the total head that are actually measured. Is also good.

[0014]

[Operation] In the device according to claim 1, the pump performance characteristic curve group measured in advance using a value corresponding to the opening water level of the intake pipe as a parameter is used to measure the opening water level of the intake pipe measured locally. Then, one pump performance characteristic curve is selected, and the discharge water amount can be calculated from this curve and the pipeline resistance curve obtained from the actual head measured at the site. At the site, it is only necessary to be able to measure the opening water level and the actual head, which simplifies the equipment.

And in the apparatus according to claim 2,
The pump performance characteristic curve corresponding to the measured opening water level was selected by calculation from the relational expression group of the discharge water amount and the total head measured by changing the opening water level of the intake pipe using the pipe system resistance value as a parameter. The amount of discharged water is calculated from the curve and the pipe resistance curve.

Further, in the method according to claims 7 and 8, a pump performance characteristic curve selected according to the measured and calculated opening water level and a pipeline resistance curve according to the measured and calculated actual head. Since the point of intersection is approximately calculated by the Newton-Raphson method and the amount of discharged water is calculated, it can be quickly calculated using a small electronic calculator or the like.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram of an embodiment of a discharge water amount measuring device of a preceding standby type pump of the present invention, and FIG.
FIG. 3 is a diagram of a group of pump performance characteristic curves showing the total head and efficiency with respect to the amount of discharged water, using a plurality of values of the opening water level of the intake pipe of the vertical axis pump shown in FIG. 1, and FIG.
5 is a characteristic curve diagram showing the relationship between the opening water level of the intake pipe and the maximum efficiency point discharge water amount in FIG. 4, and FIG. 4 is a characteristic curve diagram showing the relationship between the opening water level of the intake pipe and the maximum efficiency point total head in FIG. Fig. 5 standardizes the flow rate ratio (discharged water amount / maximum efficiency point discharged water amount) and total head ratio (total lift / maximum efficiency point total lift) with multiple values of the opening water level of the intake pipe as parameters. FIG. 6 is a diagram of a group of pump performance characteristic curves, and FIG.
6 is a flowchart of an example for calculating the amount of discharged water performed by the calculating means of FIG.

First, the structure will be described with reference to FIG. Vertical pump 1 having suction pipe 10 in suction water tank 20
2, the butterfly valve 22, the expansion tube 24, and the expansion tube 26 are sequentially connected to the vertical shaft pump 12.
6 is discharged and opened to the water tank 28. Also, the suction water tank 20
Is provided with a suction water tank water level measuring means 34 for measuring the water level, and a signal corresponding to the suction water level is given to the computing means 32. Similarly, the discharge water tank 28 is provided with discharge water tank water level measuring means 36 for measuring the water level, and a signal according to the discharge water level is given to the calculating means 32. Then, the calculating means 32 calculates the actual head hd and the intake pipe 1 from the measured water level difference.
The opening water level hs of 0 is calculated, and the actual pump head hd, the opening water level hs of the intake pipe 10 and the opening water level hs of the intake pipe 10 are used as parameters to measure the pump performance characteristic curve group and the pipe resistance measured in advance. The amount of discharged water Q is calculated using the curve and as described later. Further, a signal corresponding to the calculation result of the discharged water amount Q is given from the calculation unit 32 to the display unit 38, and the discharged water amount Q is appropriately displayed.

Next, the discharge water amount Q in the calculating means 32
The calculation method of will be described. The total head H and the efficiency η with respect to the discharged water amount Q are discharged using a plurality of values of the opening water level hs in which the intake pipe 10 of the vertical shaft pump 12 is opened to the impeller casing 16 or the suction bell mouth 18 in advance,
The data of the pump performance characteristic curve group as shown in FIG. In FIG. 2, W is the amount of water discharged at the highest efficiency point, and V is the total head of the highest efficiency point.

Further, from FIG. 2, a characteristic curve showing the relationship between the value hs of the opening water level of the intake pipe 10 and the discharge water amount W at the highest efficiency point can be shown as in FIG. Here, the relational expression of FIG. 3 is shown by W = C ₀ + C ₁ hs + C ₂ hs ² + C ₃ hs ³ (1).

From FIG. 2, a characteristic curve showing the relationship between the value hs of the opening water level of the intake pipe 10 and the total head V of the highest efficiency point is shown in FIG.
You can show it like. Here, the relational expression of FIG. 4 is represented by V = D ₀ + D ₁ hs + D ₂ hs ³ + D ₃ hs ³ (2).

The coefficient C in these equations (1) and (2)
₀ , C ₁ , C ₂ , C ₃ and D ₀ , D ₁ , D ₂ , D ₃ are constants that can be obtained by the least squares method by substituting the measured data respectively.

By the way, in FIG. 2, the pump performance in the range where the discharged water amount Q is smaller than the maximum efficiency point is the same as when the opening water level hs of the intake pipe 10 is sufficiently large, that is, when air is not sucked. Therefore, in the calculation of the discharged water amount Q, the equation representing the curve is treated separately with the highest efficiency point of the discharged water amount Q with respect to the opening water level hs of the intake pipe 10 as a branch point.

Therefore, in FIG. 2, in a range in which the discharge water amount Q is higher than the maximum efficiency point, the discharge water amount Q is divided by the discharge efficiency water amount W at the maximum efficiency point for each opening water level hs of the intake pipe 10. The normalized relationship of the total head ratio ψ (H / V) obtained by dividing the total head H by the maximum efficiency point total head V with respect to φ (Q / W) is shown in FIG. Here, the opening water level hs of the intake pipe 10
A standardized relational expression using as a parameter is expressed as ψ = A ₀ + A ₁ φ + A ₂ φ ² + A ₃ φ ³ + A ₄ φ ⁴ (3). Here, the values of A ₀ , A ₁ , A ₂ , A ₃ , and A ₄ are coefficients with each water level hs by the method of least squares as a parameter, and if the opening water level hs of the intake pipe 10 is determined, A ₀ ~
A ₄ is set as a constant.

Further, in the range in which the discharged water amount Q is larger than the maximum efficiency point, the relational expression of the pump performance characteristic curve diagram is as follows: H ₁ = ψ × V = A ₀ + A ₁ (φW) + A ₂ (φW) ² + A ₃ (ΦW) ³ + A ₄ (φW) ⁴ (4) By substituting the equations (1) and (2) into the equation (4), the pump performance characteristic curve for an arbitrary opening water level hs of the intake pipe 10 can be obtained.

Further, in the range where the discharged water amount Q is smaller than the maximum efficiency point, it is constant regardless of the opening water level hs, and the relational expression is H ₀ = B ₀ + B ₁ Q + B ₂ Q ² + B ₃ Q ³ + B ₄ It can be shown by Q ⁴ (5). Then, the measured values are substituted and the coefficients B ₀ , B ₁ , B ₂ , B ₃ , and B ₄ are obtained as constants by the least squares method.

On the other hand, the conduit resistance curve is represented by R = hd + EQ ² (6) Where hd is the actual head and E is the butterfly valve 2
It is a constant pipe system resistance value determined by the opening degree of 2 and the like.

Therefore, the discharge water amount Q is obtained from the equations (4) and (6) or the equations (5) and (6). For this reason, the coefficient data of the equations (1), (2), and (3) and the pipe system resistance value E corresponding to the opening degree of the butterfly valve 22 are stored in the computing means 32 in advance, and the vertical shaft pump 12 is installed. At the site where the intake pipe 10 is operated, signals are obtained from the suction water tank water level measuring means 34 and the discharge water tank water level measuring means 36.
The discharge water amount Q can be calculated by obtaining the opening water level hs and the actual head height hd and calculating the conduit resistance value E from the signal corresponding to the opening degree of the butterfly valve 22.

Therefore, from the measured opening water level hs, the actual head height hd, and the conduit resistance value E, from equations (4) and (6) or (5) and (6), g ₁ by the Newton-Raphson method = H ₁ -R = 0 or g ₀ = H ₀ -R = 0 is solved to determine the discharged water amount Q by the flowchart of FIG. 6.

First, a provisional initial assumed value X ₁ of the discharged water amount Q
And a threshold value ε for stopping the convergence calculation of the Newton-Raphson method are set appropriately (step 1). next,
Suction water tank water level measuring means 34 and discharge water tank water level measuring means 3
From the signal of 6, the opening water level hs of the intake pipe 10 and the actual head height hd
And the pipe system resistance value E is set from a signal corresponding to the opening of the butterfly valve 22 (step 2). And
From the opening water level hs obtained in step 2, the maximum efficiency point discharge water amount W is calculated by the equation (1), and (3)
_{Alternatively} , the coefficients A ₀ , A ₁ , A ₂ , A ₃ , and A ₄ of the equation (4) are calculated (step 3). Further, the initial assumed value X ₁ is set to the discharge water amount R ₁ (step 4), and it is determined whether the set discharge water amount R ₁ is larger or smaller than the maximum efficiency point discharge water amount W (step 5). . If R ₁ <W or R ₁ = W, R ₂ = R ₁ −g ₀ (R ₁ ) / g ₀ ′ (R ₁ ) is calculated (step 6), and | R ₂ −R ₁ |> ε is determined (step 7). If | R ₂ −R ₁ |> ε, R ₂ is set as a new discharge water amount R ₁ (step 8), and the process returns to step 5. In step 5, if R ₁ > W, then R ₂ = R ₁ −g ₁
(R ₁ ) / g ₁ ′ (R ₁ ) is calculated (step 9), and step 7 is reached. Step 7 | R ₂ -R ₁ | <repeated until ε, | R ₂ -R ₁ | if the <epsilon, and water Q discharged by the R ₁ at that time (step 10), the operation finish.

The calculation method of the discharge water amount Q, which is approximately calculated by the Newton-Raphson method, is 0.5 seconds or less in the practice of the present inventors using a 32-bit small computer (with a numerical calculation processor). Can be processed with
Due to the short sampling time, it is possible to cope with the change in the discharge water amount Q sufficiently for practical use.

FIGS. 7 and 8 are diagrams for explaining another example of obtaining the relational expression of the pump performance characteristic curve with the opening water level hs of the intake pipe 10 as a parameter.

First, in a state where the opening water level hs of the intake pipe 10 is sufficiently large and air is not sucked in, the pipe system resistance value is adjusted by the opening degree of the butterfly valve 22 to, for example, 100% discharge of the vertical shaft pump 12. Set the water flow rate to the open water level h of the intake pipe 10.
By changing s and measuring the discharge water amount Q and the total head H, the relationship between the discharge water amount Q and the total head H with respect to the opening water level hs can be shown as shown in FIG. Here, these relational expressions are: Q = a ₀ + a ₁ (hs) + a ₂ (hs) ² + a ₃ (hs) ³ + a ₄ (hs) ⁴ (7) H = b ₀ + b ₁ (hs) + b ₂ (Hs) ² + b ₃ (hs) ³ + b ₄ (hs) ⁴ (8) Coefficient a in these equations (7) and (8)
₀ , a ₁ , a ₂ , a ₃ , a ₄ , b ₀ , b ₁ , b ₂ , b ₃ , b ₄ are
It is a constant that can be obtained by the least-squares method by substituting each measured value.

Further, the opening degree of the butterfly valve 22 is variously changed to, for example, 60%, 80%, 120% of the vertical pump 12.
The discharge water amount is set, the opening water level hs of the intake pipe 10 is lowered, the discharge water amount Q and the total head H are measured, and a plurality of relationships as shown in FIG. 7 are obtained using the pipe system resistance value as a parameter. Then, a plurality of sets of coefficients of the equations (7) and (8) respectively indicating the discharged water amount Q and the total head H are obtained respectively.

Then, using the pipe system resistance value set by adjusting the opening degree of the butterfly valve 22 as a parameter, the discharge water amount Q and the total head H (7) with respect to the opening water level hs of the intake pipe 10 having a constant coefficient are set. ) And (8) are obtained. Here, if the relational expression between the discharged water amount Q and the total head H is H (hs) = c ₀ + c ₁ Q (hs) + c ₂ Q (hs) ² + c ₃ Q (hs) ³ (9), If the opening water level hs of the intake pipe 10 is arbitrarily set, a plurality of sets of the discharged water amount Q and the total head H corresponding to the opening water level hs can be calculated from a plurality of equation groups (7) and (8). The values of the discharged water amount Q and the total head H are substituted into the equation (9), and the coefficients c ₀ , c ₁ , c ₂ and c ₃ are determined as constants by the least squares method. This equation (9) is composed of a cubic equation to calculate the coefficient with the measured value using four different pipe system resistance values as parameters, but by increasing the number of pipe system resistance values as parameters, The equation (9) can be constructed by a higher order equation.

The solid line in FIG. 8 indicates the pump performance characteristic curve in the state where air is not sucked in, and the line resistance value is adjusted by the butterfly valve 22.
%, 100%, and 120% of the discharge water amount, and shows a group of curves showing the relationship between the discharge water amount Q and the total head H when the opening water level hs of the intake pipe 10 is lowered. It is a pump performance characteristic curve group calculated | required by the opening water level hs set arbitrarily. As is apparent from the figure, the broken line in FIG. 8 is the same as that shown in FIG.

Therefore, the pipe resistance value corresponding to the opening degree of the butterfly valve 22 for obtaining the relational expression groups (7) and (8) and the pipe resistance curve is stored in advance in the calculating means 32. Therefore, in the field where the vertical shaft pump 12 is installed,
The amount of discharged water Q can be calculated by obtaining the opening water level hs of the intake pipe 10 and the actual head hd.

FIG. 9 is a block diagram of another embodiment of the discharge water amount measuring apparatus of the preceding standby type pump of the present invention. In FIG. 9, the same members as those in FIG. 1 are designated by the same reference numerals to omit redundant description.

9 is different from FIG. 1 in that
In the suction water tank 20, a suction water tank water pressure measuring means 40 for measuring water pressure is arranged on the bottom surface in place of the suction water tank water level measuring means 34, and a signal according to the suction water tank pressure is given to the calculating means 32. Further, in the discharge water tank 28, a discharge water tank water pressure measuring means 42 for measuring the water pressure is arranged on the bottom surface in place of the discharge water tank water level measuring means 36, and a signal according to the discharge water tank water pressure is given to the calculating means 32. Especially. Further, the calculation means 32 causes the suction and discharge water tank water pressure measuring means 40, 42.
It is to calculate the opening water level hs and the actual head hd of the intake pipe 10 from the height difference of the positions where the positions are arranged and the measured water pressure difference. From the opening water level hs and the actual head hd, the discharge water amount Q is calculated according to the flowchart of FIG.

In FIG. 9, the water pressure measuring means 40,
Although 42 are arranged on the bottom surfaces of the suction water tank 20 and the discharge water tank 28, respectively, the positions to be arranged are not limited to the bottom surface, and may be a depth in the middle of the water tank as long as they are in water.

FIG. 10 is a constitutional view of still another embodiment of the discharge water amount measuring device of the preceding standby type pump of the present invention.
In FIG. 10, the same members as those in FIG. 1 are designated by the same reference numerals and duplicate description will be omitted.

10 differs from FIG. 1 in that
Instead of the discharge water tank measuring means 36, a discharge pressure measuring means 50 for measuring the discharge pressure of the vertical shaft pump 12 is provided, and a signal according to the discharge pressure is given to the calculating means 32. Further, the calculation means 32 calculates the actual head hd from the suction water level, the discharge pressure, and the height at which the discharge pressure measuring means 50 is provided. In FIG. 10, the discharge pressure measuring means 50 is provided upstream of the butterfly valve 22 in order to eliminate the influence of the pressure loss due to the butterfly valve 22, but if the loss coefficient of the butterfly valve 22 is known, the pressure is measured. Since the loss can be calculated, it may be provided downstream of the butterfly valve 22.

Further, a signal according to the suction water level output from the suction water tank water level measuring means 34 provided in the suction water tank 20 and a discharge water tank water pressure measuring means 42 provided on the bottom surface of the discharge water tank 28 are output. The actual head hd may be calculated from the signal corresponding to the discharge water tank water pressure and the height at which the discharge water tank water pressure measuring means 42 is provided.

The intersection of the pump performance characteristic curve selected according to the opening water level hs and the pipe resistance curve according to the actual head hd may be calculated by using an approximate calculation method other than the Newton-Raphson method. good.

The pump performance characteristic curve is the opening water level hs.
The opening water level hs is not limited to the one using the parameter itself.
The water level or the like of the suction water tank 20 having a value corresponding to the above may be used as the parameter value.

[0046]

The discharge water amount measuring apparatus and discharge water amount measuring method for the preceding standby type pump according to the present invention are configured as described above, and therefore have the following effects.

In the discharge water amount measuring device for the preceding standby type pump according to the first aspect, the pump performance characteristic curve group measured in advance using a value corresponding to the opening water level of the intake pipe as a parameter, and measured on site. Since the discharge water amount is calculated from the opening water level of the intake pipe and the actual head, the discharge water amount can be easily and accurately obtained at the site where the vertical shaft pump is installed. Moreover, the opening water level of the intake pipe and the actual head are
It can be easily measured and calculated from the respective water levels of the suction water tank and the discharge water tank, and these water level measuring means have been conventionally provided in the pumping station facility, and the configuration of the entire device is simple.

Further, in the discharge water amount measuring device of the preceding standby type pump according to the second aspect, the discharge water amount and total amount measured in advance by changing the opening water level of the intake pipe using the pipe system resistance value as a parameter. The pump performance characteristic curve is selected from the relational expression group of the pump head according to the on-site measured opening water level, and the discharge water volume is calculated, so the data itself of the pump performance characteristic curve group with the opening water level as a parameter is calculated. You don't have to remember it.

Further, in the discharge water amount measuring device of the preceding standby type pump according to the third aspect, the calculating means using the pipe system resistance value according to the opening degree of the valve interposed in the pipe system. Since the relational expression of the pipe resistance curve is obtained by, the accurate discharge water amount can be calculated regardless of the adjustment of the discharge water amount by the valve.

Further, even in the discharge water amount measuring device of the preceding stand-by type pump according to claims 4 to 6, the opening water level and the actual head are obtained by the water level measuring means, the water pressure measuring means and the discharge pressure measuring means. Therefore, similarly to the first or second aspect, the discharge water amount can be easily obtained at the site where the vertical shaft pump is installed.

Further, in the discharge water amount measuring method of the preceding standby type pump according to claim 7 or 8, the pump performance characteristic curve group measured in advance using a value corresponding to the opening water level of the intake pipe as a parameter A pump performance characteristic curve selected according to the water level, or by changing the opening water level of the intake pipe using the pipe system resistance as a parameter, selected according to the opening water level from the relational expression group of the discharge water volume and total head that was actually measured in advance. The discharge point is calculated by calculating the intersection of the pump performance characteristic curve and the pipeline resistance curve by the Newton-Raphson method, so even if a relatively small electronic calculator is used as the calculation means, the discharge can be performed within a short time. The amount of water can be obtained, and it is possible to sufficiently cope with changes in the amount of discharged water.

Further, in the discharge water amount measuring method of the preceding standby type pump according to claim 9, the pump performance characteristic curve becomes an inflection point in terms of the maximum efficiency discharge water amount at the opening water level of the intake pipe. Therefore, by expressing this point as a branch point by two equations, the pump performance characteristic curve can be expressed more accurately, and the accuracy of the calculated discharge water amount improves.

Further, in the discharge water amount measuring method for the preceding standby type pump according to claim 10, the pump performance characteristic curve is such that the discharge water amount is smaller than the maximum efficiency discharge water amount at the opening water level of the intake pipe. , Irrespective of the opening water level, it agrees with the pump performance characteristic curve for normal operation without air intake. Therefore, in the range where the amount of discharged water is less than the maximum amount of discharged water, it is not necessary to select a pump performance characteristic curve with the opening water level as a parameter, and the amount of discharged water is measured using a previously measured pump performance characteristic curve for normal operation. Can be calculated, the process of calculation processing can be omitted, and the calculation result can be obtained as quickly as that.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a discharge water amount measuring device of a preceding standby type pump according to the present invention.

FIG. 2 is a diagram of a group of pump performance characteristic curves showing the total head and efficiency with respect to the amount of discharged water, using a plurality of values of the opening water level of the intake pipe of the vertical shaft pump shown in FIG. 1 as parameters.

FIG. 3 is a characteristic curve diagram showing the relationship between the opening water level of the intake pipe and the maximum efficiency point discharge water amount in FIG.

FIG. 4 is a characteristic curve diagram showing the relationship between the opening water level of the intake pipe and the total head of maximum efficiency point in FIG.

[FIG. 5] The flow rate ratio (discharged water amount / maximum efficiency point discharged water amount) and total head ratio (total head / maximum efficiency point total head) were standardized using multiple values of the opening water level of the intake pipe as parameters. It is a figure of a pump performance characteristic curve group.

FIG. 6 is a flow chart of an example for calculating the amount of discharged water performed by the calculating means of FIG.

FIG. 7 is a diagram showing the relationship between the discharge water amount and the total head with respect to the opening water level of the intake pipe with the pipe system resistance value as a parameter.

FIG. 8: Pump performance characteristic curve in a state where air is not sucked in, and 60%, 80% in normal operation by adjusting the pipe system resistance value.
%, 100%, 120% Discharged water amount as the discharge water amount and the curve showing the relationship between the discharge water amount and the total head when the opening water level is lowered, and the pump performance characteristic curve selected from this curve at the arbitrarily set opening water level It is a characteristic view showing a group.

FIG. 9 is a configuration diagram of another embodiment of the discharge water amount measuring device of the preceding standby type pump of the present invention.

FIG. 10 is a configuration diagram of still another embodiment of the discharge water amount measuring device of the preceding standby pump of the present invention.

FIG. 11 is a diagram showing an example of a preceding standby pump.

FIG. 12 is a configuration diagram of a discharge water amount measuring device of a preceding standby type pump proposed previously.

[Explanation of symbols]

 10 Intake Pipe 12 Vertical Pump 14 Impeller 16 Impeller Casing 18 Suction Bellmouth 20 Suction Water Tank 22 Butterfly Valve 28 Discharging Water Tank 32 Calculating Means 34 Suction Water Tank Water Level Measuring Means 36 Discharging Water Tank Water Level Measuring Means 40 Suction Water Tank Water Pressure Measuring Means 42 Discharge water tank water pressure measuring means 50 Discharge pressure measuring means hs Intake pipe opening water level hd Actual head

Claims (10)

[Claims] 1. An intake pipe communicating with the atmosphere is opened in an impeller casing or a suction bell mouth below an impeller of a vertical shaft pump, and a suction water tank water level measuring means for measuring the water level of the suction water tank is provided. The discharge water tank water level measuring means for measuring the water level is provided, and the opening water level and actual head of the intake pipe calculated from the signals respectively output from the suction and discharge water tank water level measuring means, and the opening water level of the intake pipe It is configured to calculate the discharge water amount by the calculating means from the pump performance characteristic curve group of the vertical shaft pump measured in advance using a value corresponding to the parameter and the pipe system resistance value measured in advance. Discharge water amount measuring device of the preceding standby type pump. 2. The discharge water quantity measuring device for a preceding standby type pump according to claim 1, wherein the pump performance characteristic curve group measured in advance using a value corresponding to the opening water level of the intake pipe as a parameter is replaced by a pipe system. By using the relational expression group of the discharge water amount and the total head of the vertical pump that is measured in advance by changing the opening water level of the intake pipe using the resistance value as a parameter,
A discharge water amount measuring device for a preceding standby type pump, characterized in that the calculation means calculates the discharge water amount. 3. The discharge water amount measuring device for a preceding standby type pump according to claim 1, wherein the opening degree of a valve installed in the pipe system is used in place of the previously measured pipe system resistance value. A discharge water amount measuring device for a preceding standby pump, wherein the calculating means calculates the discharge water amount by using a pipe system resistance value set accordingly. 4. The discharge water amount measuring device of the preceding standby type pump according to claim 1, wherein the suction water tank water level measuring means and the discharge water tank water level measuring means are replaced with the suction water tank and the suction water tank. Water pressure measuring means is arranged in each of the discharge water tanks, and the output water level and actual head of the intake pipe calculated from the signals output from these water pressure measuring means and the height difference at which these water pressure measuring means are arranged are used. A discharge water amount measuring device for a preceding standby type pump, characterized in that the calculation means calculates the discharge water amount. 5. The discharge water amount measuring device of the preceding standby type pump according to any one of claims 1 to 3, wherein the suction water tank water level measuring means or the discharge water tank water level measuring means is used in place of the suction water tank water level measuring means or the discharge water tank water level measuring means. The water pressure measuring means is arranged in the water tank, and the opening water level and the actual head of the intake pipe calculated from the signal obtained from this water pressure measuring means and the arranged height and the signal obtained from the other water level measuring means are used, A discharge water amount measuring device for a preceding standby type pump, characterized in that the calculation means calculates the discharge water amount. 6. The discharge water amount measuring device for a preceding standby type pump according to claim 1, wherein the discharge water level measuring means is replaced with a discharge pressure for measuring a discharge pressure of the vertical shaft pump. The measuring means is provided, and the amount of water discharged by the calculating means is calculated by using the opening water level and the actual head of the intake pipe calculated from the signal obtained from the suction water tank water level measuring means and the signal obtained from the discharge pressure measuring means. A discharge water amount measuring device for a preceding standby type pump, which is configured to calculate 7. The intake air opened from the signal output from the suction water tank water level measuring means or the water pressure measuring means arranged in the suction water tank to the impeller casing below the impeller of the vertical pump or the suction bell mouth in communication with the atmosphere. Calculate the opening water level of the pipe, the discharge water volume of the vertical pump measured in advance using a plurality of values according to the opening water level of this intake pipe as a parameter, and the pump performance characteristic curve group of the total head The relational expression of the pump performance characteristic curve with the value of the opening water level as a parameter is selected, and the signal output from the suction water tank water level measuring means or the water pressure measuring means arranged in the suction water tank and the discharge water tank water level measuring means or the discharge water tank The actual head is calculated from the signal output from the water pressure measuring means or the discharge pressure measuring means arranged at, and the pipeline resistance is calculated from this actual head and the set pipe system resistance value. The relational expression of the anti-curve is calculated, and the intersection of the relational expression of the pump performance characteristic curve and the relational expression of the pipeline resistance curve is approximately calculated by the Newton-Raphson method to calculate the discharge water amount discharged from the vertical pump. A method for measuring the amount of water discharged from a preceding standby type pump, which is characterized in that 8. The method of measuring the discharge water amount of a preceding standby type pump according to claim 7, wherein a plurality of values corresponding to the opening water level of the intake pipe are used as parameters to replace the pump performance characteristic curve group measured in advance. A pump that uses the value of the opening water level of the intake pipe calculated from the relational expression group of the discharge water amount and the total head measured in advance by changing the opening water level of the intake pipe using a plurality of pipe system resistance values as parameters. A method for measuring the discharge water volume of a preceding standby type pump characterized by selecting a relational expression of a performance characteristic curve. 9. The discharge water amount measuring method for a preceding standby type pump according to claim 7 or 8, wherein the relational expression of the pump performance characteristic curve is divided into points of the maximum efficiency discharge water amount at the opening water level of the intake pipe. The point is a method for measuring the discharge water amount of a preceding standby type pump characterized by being expressed by two expressions. 10. The method for measuring the discharge water amount of the preceding standby type pump according to claim 9, wherein the relational expression of the pump performance characteristic curve is such that the discharge water amount is less than the maximum efficiency discharge water amount at the opening water level of the intake pipe. A method for measuring the amount of discharge water of a preceding standby type pump, which is calculated by using a pump performance characteristic curve of normal operation in which air is not taken in.