JP7306918B2 - Water Hammer Analyzer - Google Patents

Description

An embodiment of the present invention relates to a water hammer analysis device for analyzing a water hammer phenomenon occurring in a pipeline system.

In a piping system that contains fluid, the fluid is regulated by a regulating valve or the like so that it reaches a prescribed flow rate at a prescribed time. A so-called water hammer phenomenon occurs in which the fluid pressure inside fluctuates greatly. When this water hammer phenomenon occurs, depending on the conditions, there is a risk of temporarily exceeding the design pressure and causing damage to the pipeline itself or equipment installed in the pipeline. For this reason, various means have been used to predict or prevent water hammer phenomena. Techniques have been proposed to control to within the allowable range.

As for the general analysis method used for predicting water hammer phenomenon, the fluid motion equation and the continuity equation that are one-dimensionalized in the pipeline axial direction are fixed between the pipeline axial direction division length and the time division length. A characteristic curve method for setting and simplifying the relationship of is known, and dedicated fluid analysis software is commercially available. In such conventional fluid analysis software, a pipe system model and boundary conditions such as valve opening/closing operations are given as data, and calculations are performed by pre-programmed codes. Therefore, users of this fluid analysis software need to know how to input data, but they are not told how the analysis was performed, so it is a black box.

Also, when dealing with a pipeline system that does not meet the assumptions and limitations that arise in the process of creating a program for fluid analysis software, it becomes necessary to modify the programmed code. Furthermore, from the viewpoint of quality assurance of fluid analysis software, verification of whether the analysis of the water hammer phenomenon was performed correctly when the programmed code was created and modified (verification), and confirmation of the validity of the analysis results So-called V&V, which performs (validation), is required.

Japanese Patent Laid-Open No. 11-305842

However, with the above-mentioned conventional fluid analysis software, if the programmed code is not disclosed, it is not easy to perform V&V for the analysis of the water hammer phenomenon only by the user who created the pipe system model etc. as data. . Also, even if the programmed code is disclosed, a special environment such as a debugger is required to verify the calculation process step by step, and V&V requires considerable labor.

The embodiments of the present invention have been made in consideration of the above-mentioned circumstances, and can easily verify whether the analysis of the water hammer phenomenon has been correctly performed without using knowledge of a special program language, and can It is an object of the present invention to provide a water hammer analysis device capable of easily confirming the validity of results.

A water hammer analysis device according to an embodiment of the present invention is a water hammer analysis device that analyzes a water hammer phenomenon that occurs due to changes in the head and flow rate of a fluid in a pipeline, and records pipe specification information for each part of the pipeline. pipe specification information recording means; water hammer analysis parameter information recording means for recording a time history of water hammer analysis parameter information including water head and flow rate in each part in the pipeline; values of the pipe specification information and the water hammer analysis; calculation means for calculating the current time value of the water hammer analysis parameter information using a calculation formula using the previous time value of the parameter information; and display means capable of displaying the calculation formula of the calculation means relating to a different time. It is characterized in that it is configured to have

According to the embodiment of the present invention, it is possible to easily verify whether or not the analysis of the water hammer phenomenon has been correctly performed without using knowledge of a special program language, and to easily confirm the validity of the analysis result.

The block diagram which shows the structure of the water hammer analysis apparatus which concerns on 1st Embodiment. FIG. 2 is a model diagram showing the pipeline configuration of a single pipe in the first embodiment; FIG. 2 is a configuration diagram showing the configuration of the pipe specification recording spreadsheet of FIG. 1; FIG. 4 is a configuration diagram showing another portion of the pipe specification recording spreadsheet of FIG. 3; FIG. 2 is a configuration diagram showing the configuration of a traveling wave information value spreadsheet in FIG. 1; FIG. 2 is a configuration diagram showing the configuration of a backward wave information value spreadsheet in FIG. 1; FIG. 2 is a configuration diagram showing the configuration of the flow rate value spreadsheet of FIG. 1; FIG. 2 is a configuration diagram showing the configuration of the water head value spreadsheet of FIG. 1; The graph which shows the analysis result by the water hammer analysis apparatus of 1st Embodiment. The block diagram which shows the structure of the water hammer analysis apparatus which concerns on 2nd Embodiment. The model figure which shows the pipeline structure of the composite piping in 2nd Embodiment. FIG. 11 is a configuration diagram showing the configuration of the pipe specification recording spreadsheet of FIG. 10; FIG. 11 is a configuration diagram showing respective configurations of the forwarding wave information value spreadsheet (FIG. 13A) and the backward wave information value spreadsheet (FIG. 13B) of FIG. 10; FIG. 11 is a configuration diagram showing the configuration of each of the flow rate value spreadsheet (FIG. 14(C)) and the water head value spreadsheet (FIG. 14(D)) of FIG. 10; The graph which shows the analysis result of the flow value by the water hammer analysis apparatus of 2nd Embodiment. The graph which shows the analysis result of the water head value by the water hammer analysis apparatus of 2nd Embodiment. The block diagram which shows the structure of the water hammer analysis apparatus which concerns on 3rd Embodiment. FIG. 18 is a configuration diagram showing the configuration of the pipe specification recording spreadsheet of FIG. 17; FIG. 18 is a configuration diagram showing the configuration of each of the forwarding wave information value spreadsheet (FIG. 19A) and the backward wave information value spreadsheet (FIG. 19B) of FIG. 17; FIG. 17 is a configuration diagram showing the respective configurations of the decompression flag spreadsheet (FIG. 20(C)) and the steam generation amount spreadsheet (FIG. 20(D)) of FIG. 17; FIG. 18 is a configuration diagram showing the configuration of each of the flow rate value spreadsheet (FIG. 21(E)) and the water head value spreadsheet (FIG. 21(F)) of FIG. 17; 20(C) is a flowchart showing formula processing for creating the decompression flag spreadsheet of FIG. 20(C). 20(D) is a flow chart showing formula processing for creating the steam production amount spreadsheet of FIG. 20(D). 21(F) is a flow chart showing formula processing for creating the head value spreadsheet.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on drawing.
[A] First embodiment (Figs. 1 to 9)
FIG. 1 is a block diagram showing the configuration of the water hammer analysis device according to the first embodiment. The water hammer analysis device 10 shown in FIG. 1 is designed to detect changes in the head and flow rate of the fluid in the pipeline due to the opening and closing of valves in the pipeline, changes in the boundary conditions of the hydraulic head or flow rate in the pipeline, and the like. This is to analyze the water hammer phenomenon that occurs in However, this water hammer analysis device 10 does not analyze the water hammer phenomenon accompanied by the water column separation phenomenon that occurs when the water head of the fluid in the pipeline becomes equal to or less than the steam head (steam head + pipe height). .

The water hammer analysis device 10 described above includes a pipe specification recording spreadsheet 11 as pipe specification information recording means, a water hammer analysis parameter information spreadsheet 12 as water hammer analysis parameter information recording means, a calculation means 13, and a display means. 18 and . Among these, the water hammer analysis parameter information spreadsheet 12 includes a traveling wave information value spreadsheet 14 as traveling wave information value recording means, a backward wave information value spreadsheet 15 as backward wave information value recording means, and a flow rate value recording It comprises a flow rate value spreadsheet 16 as means and a water head value spreadsheet 17 as water head value recording means. Each of these spreadsheets 14, 15, 16 and 17 stores calculation formulas of calculation means 13 which will be described in detail later. The display means 18 also displays the pipe specification record spreadsheet 11 and the water hammer analysis parameter information spreadsheet 12 .

The pipe specification recording spreadsheet 11, the traveling wave information value spreadsheet 14, the receding wave information value spreadsheet 15, the flow rate value spreadsheet 16, and the water head value spreadsheet 17 are, as shown in FIGS. 1 is a spreadsheet software spreadsheet with multiple cells set up by rows and columns. In addition, the pipe specification recording spreadsheet 11, the traveling wave information value spreadsheet 14, the backward wave information value spreadsheet 15, the flow rate value spreadsheet 16, and the water head value spreadsheet 17 contain information on each part in the pipe (pipe specification information, Forward wave information value, backward wave information value, flow rate value, water head value) are continuously recorded in the row direction for each portion of the pipe line having the same pipe inner diameter or pipe cross-sectional area.

Here, as shown in FIG. 2, a single pipeline 20 to which the water hammer analysis device 10 is applied has, for example, a pipeline length of 360 m, a pipe inner diameter of 0.5 m, and a pipe cross-sectional area of 0.5 m. The specifications are 196 m ² and a pipe friction coefficient of 0.018. Further, the pipeline 20 has an upstream end 20A with a steady water head value of 150 m, and a downstream end 20B is provided with a terminal valve 21 that fully closes in 2 seconds after being fully opened. The fluid flowing through the conduit 20 is, for example, water, and the speed of sound in the fluid is 1200 m/s. In the water hammer analysis device 10 of FIG. 1, when the end valve 21 is fully opened and the fluid in the pipeline 20 is flowing at a steady flow rate of 0.477 m ³ /s, when the end valve 21 is fully closed in 2 seconds It analyzes the water hammer phenomenon that occurs in the pipeline 20 . The analysis time interval at this time is 0.1 seconds.

In the pipe specification recording spreadsheet 11 of the water hammer analysis device 10, as shown in FIG. Each portion of the pipeline 20 is set in the column direction. That is, the end 20A of the pipeline 20 is set in the second line, the downstream end 20B is set in the fifth line, and the nodes between the upstream end 20A and the downstream end 20B are set in the third line and the fourth line, respectively. In addition, each line of the pipe specification recording spreadsheet 11 contains pipe specification information, such as the pipe inner diameter of each part of the pipe 20, the pipe cross-sectional area of each part of the pipe 20, the sound velocity in the fluid in the pipe 20, the fluid in the pipe 20 The coefficient of pipe friction during flow, the coefficients B, R, .zeta., .theta., the pipe height (the height of each part of the pipe 20 from the reference surface), and the steam head are individually set. Thus, in the pipe specification recording spreadsheet 11, values of pipe specification information for each part of the pipeline 20 are recorded in each cell set in rows and columns.

The above-mentioned coefficients B, R, θ, and ζ are the speed of sound at each part of the pipe 20, a; , and the gravitational acceleration is g, the definition is as follows.

Here, the coefficient ζ represents a ratio obtained by dividing the distance propagated at the speed of sound a per one analysis time step dt by the pipe axis length step dx of the pipe 20 . In order to stably solve the water hammer phenomenon, it is necessary to satisfy the condition that the tube axis length step dx is equal to or greater than the distance propagated at the speed of sound a per one analysis time step dt. It is desirable to set the analysis time step dt and the tube axis length step dx so that ≦1.

Furthermore, in the pipe specification recording spreadsheet 11, as shown in FIG. 4, valve opening τ and Cv values are recorded in a format different from the above-described pipe specification information such as sound velocity and pipe inner diameter. That is, the valve opening degree τ is recorded in the fourth column of the pipe specification recording spreadsheet 11, the Cv value is recorded in the fifth column, and the analysis time interval dt is recorded at 0.1 seconds over the 21st to 42nd rows. It is

時刻０～約２秒間で閉鎖する終端弁２１のＣｖ値は、第２１行に終端弁２１が全開時の値が、第４２行に終端弁２１が全閉時の値がそれぞれ記録されている。 τ=1.000 and τ=0.000 respectively represent the end valve 21 fully open and the end valve 21 fully closed. In addition, the Cv value expresses the characteristic that the water head loss Δh of the terminal valve 21 installed at the downstream end 20B of the pipeline 20 is proportional to the square of the flow rate Q of the fluid passing through the terminal valve 21 by the following equation 5. It is what I did.

As for the Cv value of the terminal valve 21 that closes from time 0 to about 2 seconds, the value when the terminal valve 21 is fully open is recorded on the 21st line, and the value when the terminal valve 21 is fully closed is recorded on the 42nd line. .

The traveling wave information value spreadsheet 14 shown in FIGS. 1 and 5 shows the time history of each part in the pipeline 20 in the information value of the traveling wave transmitted from the upstream to the downstream in the pipeline 20 as the time of the water hammer analysis parameter information. Record as history. 1 and 6, the backward wave information value spreadsheet 15 shown in FIG. 1 and FIG. Record as a time history. Furthermore, the flow rate value spreadsheet 16 shown in FIGS. 1 and 7 records the time history of the flow rate value of the fluid flowing through each part of the pipeline 20 as the time history of the water hammer analysis parameter information. The water head value spreadsheet 17 shown in FIGS. 1 and 8 records the time history of the water head value of each part in the pipeline 20 as the time history of the water hammer analysis parameter information.

In these forward wave information value spreadsheet 14, backward wave information value spreadsheet 15, flow rate value spreadsheet 16, and water head value spreadsheet 17, 120 m, which is the product of the analysis time step and the sound speed in the fluid, is used as the pipe axis length step. , each part of the pipeline 20 obtained by virtually dividing the pipeline 20 in the axial direction is set in the column direction. That is, the upstream end 20A of the pipeline 20 is set in the second row, the downstream end 20B is set in the fifth row, and the nodes between the upstream end 20A and the downstream end 20B are set in the third row and the fourth row, respectively.

Further, a time axis is set in each row of the traveling wave information value spreadsheet 14, the backward wave information value spreadsheet 15, the flow rate value spreadsheet 16, and the water head value spreadsheet 17, and the initial time (time 0) is set in the fourth row. As for the conditions, the times are sequentially set in each line after the fifth line, with the analysis time increment being 0.1 second.

In each of the forwarding wave information value spreadsheet 14, the backward wave information value spreadsheet 15, the flow rate value spreadsheet 16, and the water head value spreadsheet 17, each part of the pipeline 20 is shown in each cell set by rows and columns. Time histories of forward wave information values, backward wave information values, discharge values, and water head values are recorded.

The traveling wave information values of each part in the pipeline 20 recorded in the traveling wave information value spreadsheet 14 shown in FIG. and the value of the flow rate at the same time, it is calculated by Equation 6.

That is, the traveling wave information value CP is the flow rate value of the flow rate value spreadsheet 16 in the same column at the same time (same row) as the traveling wave information value CP, Q, and one upstream (one in FIG. 7) at the same time. The flow rate value of the flow rate value spreadsheet 16 in the left column) is Q _A , the head value of the water head value spreadsheet 17 in the same column at the same time (same row) as the traveling wave information value CP is H, and one at the same time. Assuming that the water head value of the water head value spreadsheet 18 on the upstream side (one left column in FIG. 8) is _HA , the coefficients B, R, θ, ζ, and pipe cross-sectional area A recorded in the pipe specification recording spreadsheet 11 is given by the following Equation 6.

The backward wave information value of each part in the pipeline 20 recorded in the backward wave information value spreadsheet 15 shown in FIG. and the simultaneous value of the flow rate value, it is calculated by Equation 7.

That is, the backward wave information value CM is the flow rate value of the flow rate value spreadsheet 16 in the same column at the same time (same row) as the backward wave information value CM, Q, and one downstream (one in FIG. 7) at the same time. The flow rate value of the flow rate value spreadsheet 16 in the right column) is _QB , and the head value of the water head value spreadsheet 17 at the same time (same row) and the same column as the backward wave information value CM is H, and one at the same time. Assuming that the water head value of the water head value spreadsheet 17 on the downstream side (one column to the right in FIG. 8) is _HB , the coefficients B, R, θ, ζ, and pipe cross-sectional area A recorded in the pipe specification recording spreadsheet 11 are is given by the following Equation 7.

As can be seen from these Equations 6 and 7, the traveling wave information value and Equation 6 are not defined at the upstream end 20A, and are entered and recorded in cells corresponding to those other than the upstream end 20A in the traveling wave information value spreadsheet 14. be done. Also, the backward wave information value and Equation 7 are not defined at the downstream end 20B, and are input and recorded in the cells corresponding to those other than the downstream end 20B in the backward wave information value spreadsheet 15 . Also, the coefficient ζ defined by Equation 4 must be set to be a positive number of 1 or less, as can be seen from Equations 6 and 7 as well.

The current time value of the water head value of each part in the pipeline 20 recorded in the water head value spreadsheet 17 shown in FIG. In the pipeline portion other than the downstream end 20B), as shown in Equation 8, it is an average value obtained by dividing the sum of the forward wave information value one time ago value and the backward wave information value one time ago value by 2, At the downstream end 20B of the pipe 20 having the same pipe inner diameter or pipe cross-sectional area, when the current time value of the flow rate value is calculated first, as shown in Equation 9, the value of the traveling wave information value one time before , the current time value of the flow rate value is multiplied by the coefficient B (the value of Equation 1 obtained by dividing the sound velocity a in the fluid in the pipeline 20 by the product of the pipe cross-sectional area A in the pipeline 20 and the gravitational acceleration g) It is the value obtained by subtracting the value.

That is, the head values recorded in the head value spreadsheet 17 are given in the fourth row as the initial time value as the initial condition, and in FIG. 8, the constant head value is given in the second column even at the upstream end 20A. Cells of the spreadsheet given as numerical values in this way are shown in gray background color in FIG. Assuming that the current time value of the head value in the fifth and subsequent rows is H, the value of the forward wave information value one time before in the same column is CP _-1 , and the value of the backward wave information value in the same column one time before is CM _-1 . , it is given by the following Equation 8 except for the upstream end 20A and the downstream end 20B.

ここで、計数Ｂは、数式１で計算されて管仕様記録スプレッドシート１１に記録された値である。 At the downstream end 20B, the flow rate value of the flow rate value spreadsheet 16 is first calculated according to the opening of the terminal valve 21 as described later, so the current time value of the head value in the fifth row of the head value spreadsheet 17 is calculated. H is given by the following equation 9, where Q is the same flow rate value at the same time.

Here, the count B is the value calculated by Equation 1 and recorded in the pipe specification recording spreadsheet 11.

If the current time value of the head value is calculated first, the current time value of the flow rate value of each part in the pipeline 20 recorded in the flow rate value spreadsheet 16 shown in FIG. The value obtained by subtracting the current time value of the water head value from the value of the traveling wave information value one time ago is taken as a coefficient B (the sound velocity in the fluid in the pipeline 20 divided by the product of the pipe cross-sectional area in the pipeline 20 and the gravitational acceleration. or the value obtained by subtracting the value of the backward wave information value one time ago from the current value of the head value and dividing the value by the coefficient B, as shown in Equation 11.

That is, when the current time value Q of the water head value is calculated first, the current time value Q of the flow rate value recorded in the flow rate value spreadsheet 16 is the value of the traveling wave information value one time before in the same column. It is given by the following formula 10 or formula 11 using the coefficient B recorded in the pipe specification recording spreadsheet 11 with CP ₋₁ and _the backward wave information value one time earlier in the same column as CM −1 .

Further, the current time value Q of the flow rate value at the downstream end 20B of the pipeline 20 to which the terminal valve 21 is attached is _expressed by the following equation 12- 1 and Equation 12-2.

Here, the coefficient B is the value defined by Equation 1 recorded in the pipe specification recording spreadsheet 11 at the downstream end 20B, and Cv is the downstream end 20B of the pipe specification recording spreadsheet 11 as shown in FIG. Of the values recorded as the time history in the 21st to 42nd rows of the 5th column corresponding to , the value of the corresponding time is referred to.

The aforementioned calculation means 13 shown in FIG. Sheet 15, flow rate value spreadsheet 16, head value spreadsheet 17) of the water hammer analysis parameter information (traveling wave information value, backward wave information value, flow rate value, water head value) recorded at the previous time value or the same time value is used to calculate the current time value of the desired water hammer analysis parameter information (advancing wave information value, receding wave information value, flow rate value, water head value) by a calculation formula. Specifically, the calculation formulas of this calculation means 13 are Formula 6 for calculating the forward wave information value, Formula 7 for calculating the backward wave information value, Formula 8 and Formula 9 for calculating the water head value, and Formula 9 for calculating the flow rate value. Equation 10, Equation 11, Equation 12-1 and Equation 12-2. Calculation formulas relating to these different times are provided so as to be displayed on the display means 18 .

The calculation formulas (Formula 6 to Formula 12-2) of this calculation means 13 are the water hammer analysis parameter information spreadsheet 12 (forward wave information value spreadsheet 14, backward wave information value spreadsheet 15, flow rate value spreadsheet 16, water head Input and record the current time value of the water hammer analysis parameter information (advancing wave information value, receding wave information value, flow rate value, water head value) in the value spreadsheet 17), and the calculated numerical value is entered in the cell Record. These formulas 6 to 12-2 are first entered into the cells of the fifth line next to the fourth line where the initial conditions are recorded, and the water hammer analysis parameter information (progress wave information value, receding wave information value, discharge value, water head value) are calculated and recorded, then copied and entered in the cells of each row from the 6th row onwards, and the water hammer at the time corresponding to each cell Calculate and record the numerical value of the analysis parameter information.

For example, in the water head value spreadsheet 17 shown in FIG. The water head value at the time corresponding to each cell is calculated and recorded according to Equation 8. Furthermore, in this water head value spreadsheet 17, the formula 9 is input and recorded in each cell of the fifth row and the fifth row corresponding to the downstream end 20B of the pipeline 20, and according to this formula 9, each cell corresponds to The head value is calculated and recorded.

In addition, in the flow rate value spreadsheet 16 shown in FIG. 7, the fifth and subsequent rows of the second, third, and fourth columns corresponding to the upstream end 20A and the node of the pipeline 20 where the end valve 21 is not installed Equations 10 and 11 are input and recorded in each cell, and the flow rate value at the time corresponding to each cell is calculated and recorded by these Equations 10 and 11. Furthermore, in this flow rate value spreadsheet 16, formulas 12-1 and 12-2 are provided in each cell after the fifth row of the fifth column corresponding to the downstream end 20B of the pipeline 20 in which the terminal valve 21 is installed. The flow rate value at the time corresponding to each cell is calculated and recorded by these formulas 12-1 and 12-2.

FIG. 9 shows the analysis results of the first embodiment analyzed in this manner as the time history of the flow rate and pressure at the downstream end 20B of the pipeline 20 in which the terminal valve 21 is installed. In FIG. 9, pressure values are shown, and these pressure values are converted by multiplying the water head value H by the fluid density ρ and the gravitational acceleration g. As can be seen from FIG. 9, the flow value at the downstream end 20B becomes zero with the closing of the end valve 21 after 2 seconds, while the pressure at the downstream end 20B rises with the beginning of the closing of the end valve 21 and It can be seen that the water hammer phenomenon in which the pressure wave propagates back and forth between the upstream end 20A and the downstream end 20B is simulated even after closing of 21 .

With the configuration as described above, according to the first embodiment, the following effect (1) can be obtained.
(1) According to the water hammer analysis device 10, the water hammer analysis parameter information spreadsheet 12 (traveling wave information value spreadsheet 14, receding wave information value spreadsheet 15, flow rate value spreadsheet 16, water head value spreadsheet 17) Formulas for water hammer analysis and numerical values determined by these formulas are entered and recorded in the cells. For this reason, the water hammer analysis parameter information spreadsheet 12 (advancing wave information value spreadsheet 14, receding wave information value spreadsheet 15, flow rate value spreadsheet 16, water head value spreadsheet 17) clearly indicates all the analysis processes of the water hammer phenomenon. Therefore, by comparing the formulas entered in each row of the same column of the water hammer analysis parameter information spreadsheet 12, it can be determined whether the water hammer phenomenon has been correctly analyzed without using a special program language. Easy to verify.

In addition, the numerical values recorded in the cells of the water hammer analysis parameter information spreadsheet 12 (traveling wave information value spreadsheet 14, receding wave information value spreadsheet 15, flow rate value spreadsheet 16, water head value spreadsheet 17) are graphed. By displaying the waveform, the validity of the analysis result by the water hammer analysis device 10 can be easily confirmed.

[B] Second embodiment (Figs. 10 to 16)
FIG. 10 is a block diagram showing the configuration of the water hammer analysis device according to the second embodiment. In the second embodiment, parts similar to those in the first embodiment are denoted by the same reference numerals as those in the first embodiment to simplify or omit the description.

The water hammer analysis device 25 of the second embodiment, as shown in FIG. 11, switches the flow of fluid between the main water pipe 26 that sends water as fluid from upstream to downstream and its bypass pipe 27. It analyzes the water hammer phenomenon that sometimes occurs. The flow of fluid flowing in the main water pipe 26 from the upstream end 26A (water head value 10 m) to the downstream end 26B (water head value 0 m) is stopped by closing the main water valve 8, and instead, it is arranged in the bypass pipe 27. The water hammer analysis device 25 analyzes the water hammer phenomenon that occurs when switching the flow of fluid via the bypass valve 27 by opening the bypass valve 9 .

As a pipeline configuration, the main water pipe 26 is composed of pipes 1, 2, 3, and 4 arranged in order from the upstream side to the downstream side, and the bypass pipe 27 is arranged from the upstream side to the downstream side. 5 and tubes 6 are arranged in sequence. A main water valve 8 is installed between the pipes 2 and 3 of the main water pipe 26 and a bypass valve 9 is installed between the pipes 5 and 6 of the bypass pipe 27 . Further, the pipe 1, the pipe 2 and the pipe 5 are connected at a first collective branch (indicated as "first branch" in FIGS. 13 and 14), and the pipe 3, the pipe 4 and the pipe 6 are connected at a second collective branch. It is connected at a portion 32 (indicated as "second branch" in FIGS. 13 and 14).

Further, the pipe 5 is provided with an intermediate node 28 between the first collecting branch 31 and the bypass valve 9 , and the pipe 6 is provided with an intermediate node 29 between the bypass valve 9 and the second collecting branch 32 . The main water pipe 26 (pipe 1, pipe 2, pipe 3, and pipe 4) has, for example, a pipe inner diameter of 0.02 m and a pipe cross-sectional area of 3.14×10 ⁻⁴ m ² . 2, pipe 3 and pipe 4 each have a pipe length of 5 m. The bypass pipe 27 (pipe 5 and pipe 6) has a pipe inner diameter of 0.01 m and a pipe cross-sectional area of 7.85×10 ⁻⁵ m ² , and each of the pipes 5 and 6 has a pipe length of 10 m. . Moreover, the sound velocity in the fluid flowing through the main water pipe 26 and the bypass pipe 27 is 1250 m/s. Furthermore, the Cv value when the main water supply valve 8 is fully open is 1.00×10 ⁻⁸ m ⁵ /s ² , and the Cv value when the bypass valve 9 is fully open is 0.25×10 ⁻⁸ m ⁵ /s ^{2 .} is.

As shown in FIGS. 10 to 14, the water hammer analysis device 25 includes a pipe specification recording spreadsheet 33 as pipe specification information storage means, and a water hammer analysis parameter information spreadsheet 34 as water hammer analysis parameter information recording means. , and computing means 35 . Among them, the water hammer analysis parameter information spreadsheet 34 includes a traveling wave information value spreadsheet 36 as traveling wave information value recording means, a backward wave information value spreadsheet 37 as backward wave information value recording means, and a flow rate value recording It comprises a flow rate value spreadsheet 38 as means and a water head value spreadsheet 39 as water head value recording means. Each of these spreadsheets 36, 37, 38, 39 stores calculation means 35, which will be described in detail later.

In the pipe specification recording spreadsheet 33, the traveling wave information value spreadsheet 36, the backward wave information value spreadsheet 37, the flow rate value spreadsheet 38, and the water head value spreadsheet 39, the pipelines are arranged in the column direction in the same manner as in the first embodiment. Each part of the pipeline is set by virtually dividing (the main water pipe 26 and the bypass pipe 27) in the pipe axis direction. In addition, in these pipe specification recording spreadsheet 33, traveling wave information value spreadsheet 36, backward wave information value spreadsheet 37, flow rate value spreadsheet 38, and water head value spreadsheet 39, pipelines (main water pipe 26, bypass, 27) The information of each part (pipe specification information, traveling wave information value, backward wave information value, flow rate value, water head value) is different in pipe inner diameter or pipe cross-sectional area of the pipe (main water pipe 26, bypass pipe 27) Concentrated pressure loss parts such as different diameter pipe connections, valves provided in pipelines (main water pipe 26, bypass pipe 27), orifices (main water pipe 8, bypass valve 9), pipelines (main water pipe 26, bypass The collective branch portions (the first collective branch portion 31, the second collective branch portion 32) provided in the pipe 27) are recorded at intervals of one or more rows in the column direction.

In the pipe specification recording spreadsheet 33, pipe specification information such as the pipe inner diameter is set in the row direction in the same manner as in the first embodiment. Further, in the traveling wave information value spreadsheet 36, the backward wave information value spreadsheet 37, the flow rate value spreadsheet 38, and the water head value spreadsheet 39, the time axis is set in the row direction, and the initial condition is set at the initial time of the fourth row. set. In each of the traveling wave information value spreadsheet 36, the backward wave information value spreadsheet 37, the flow rate value spreadsheet 38, and the water head value spreadsheet 39, each row after the fifth row shows the time with an analysis time interval of 0.1 second. are sequentially set, and the time history of the water hammer analysis parameter information (traveling wave information value, receding wave information value, flow rate value, water head value) is recorded in the cells of each row.

In the traveling wave information value spreadsheet 36, the backward wave information value spreadsheet 37, the flow rate value spreadsheet 38, and the water head value spreadsheet 39, the time histories of the traveling wave information value, the backward wave information value, the flow rate value, and the water head value are recorded, respectively. Formulas as calculation means 35 for calculating this time history (formula 6 for forwarding wave information value spreadsheet 36, formula 7 for backward wave information value spreadsheet 37, flow rate value spreadsheet 38 Equation 10, Equation 11, Equation 14-1 and Equation 14-2, Equation 8, Equation 9, Equation 15, Equation 16-1 and Equation 16-2 for the head value spreadsheet 39) are entered and recorded . These formulas are copied to each cell of the 6th and subsequent rows in each column corresponding to each part of the pipeline (main water pipe 26, bypass pipe 27). entered and recorded.

Each spreadsheet will now be described in more detail.
In the pipe specification record spreadsheet 33 shown in FIG. 12, one empty row is provided at the boundary between pipes, thereby clarifying the boundary between pipes and improving readability. Also, in this pipe specification recording spreadsheet 33, the time history of the Cv (Cv1) value of the main water valve 8 is shown in the cells after the 21st row of the 6th column corresponding to the pipe 2 on the upstream side of the main water valve 8. The time history of the Cv (Cv2) value of the bypass valve 9 is recorded in the cells from the 21st row onwards in the 16th column corresponding to the pipe 5 on the upstream side of the bypass valve 9 . Also, the cells in the third, fifth and fourteenth columns corresponding to the first branching group 31, and the thirteenth cells in the ninth, eleventh and twentieth columns corresponding to the second branching group 32 A branch coefficient is set and recorded in the row cell. The coefficient of this branch is Equation 13 which is the sum of the inverses of the B values of the columns involved in the set branches 31,32.

For example, in the 13th row cells of the 3rd column, the 5th column and the 14th column corresponding to the first set branching unit 31, the reciprocal of the B value in the 3rd column, the reciprocal of the B value in the 5th column and the 1st The sum of the reciprocals of the 14 columns of B values is set and recorded respectively.

By referring to the pipe specification information in the pipe specification recording spreadsheet 33 set in this way, a forward wave information value spreadsheet 36 shown in FIG. 13(A), a backward wave information value spreadsheet 37 shown in FIG. Calculations are performed using the above formulas in the flow rate value spreadsheet 38 shown in FIG. 14(C) and the water head value spreadsheet 39 shown in FIG. 14(D).

That is, in the traveling wave information value spreadsheet 36 shown in FIG. Equation 6 and its calculated value are input to the cells excluding the valve 8 downstream starting end (8th column), the second collection branching portion starting end (11th column), and the bypass valve 9 downstream starting end (18th column)}. Also, in the backward wave information value spreadsheet 37 shown in FIG. 7 and its calculated value are input to the cells excluding the terminal end (9th and 20th columns), the downstream end of the pipe 4 (12th column), and the upstream end of the bypass valve 9 (16th column)}.

In the flow rate value spreadsheet 38 shown in FIG. 14(C), the numerical value of the initial condition is entered in the initial time (fourth row). Then, at the current time (fifth row) following the initial time, the second and twelfth columns where the water head value is set as the boundary condition, and the fifteenth column corresponding to the intermediate nodes 28 and 29 that are not connected ends of the pipe and the 19th row, and the 3rd, 5th, 9th, 11th, 14th and 20th rows corresponding to the first and second collective branch portions 31 and 32 as will be described later. These 2nd and 12th columns, 15th and 19th columns, and 3rd, 5th, 9th, 11th, 14th and 20th columns, since the values are calculated first. Enter Equation 10 or Equation 11 in the column cell to calculate the current flow rate value from the current head value.

In addition, the current time value of the flow rate value of the fluid passing through the main water valve 8 and the bypass valve 9, which are the concentrated stress loss portions, is the Cv value that indicates the relationship between the flow rate and the head difference in the main water valve 8 and the bypass valve 9. , the value of the forward wave information value on the upstream side of the main water supply valve 8 and the bypass valve 9 one time ago, the value of the backward wave information value on the downstream side of the main water supply valve 8 and the bypass valve 9 one time ago, and the main The sound velocity in the fluid in the upstream pipes (pipe 2, pipe 5) with respect to the water supply valve 8 and the bypass valve 9 is the product of the pipe cross-sectional area of the upstream pipe (pipe 2, pipe 5) and the gravitational acceleration. and the sound velocity in the fluid in the pipeline (pipe 3, pipe 6) on the downstream side with respect to the main water valve 8 and the bypass valve 9. It is calculated by Equations 14-1 and 14-2 based on the coefficient B2 divided by the product of the cross-sectional area and the gravitational acceleration.

That is, in the 6th column corresponding to the upstream end of the main water supply valve 8 and the 16th column corresponding to the upstream end of the bypass valve 9, the Cv value in the 21st row of the pipe specification recording spreadsheet 33 is referred to, and the following A flow rate value is calculated as shown in Equations 14-1 and 14-2. That is, the B value of the row (sixth row and sixteenth row) corresponding to the upstream ends of the main water supply valve 8 and the bypass valve 9 is set to B1, and the row corresponding to the downstream end of the main water supply valve 8 and the bypass valve 9 (the eighth column, 18th column) is B2, the backward wave information value one time before at the downstream end of the main water valve 8 and bypass valve 9 is CM-1, the upstream end of the main water valve 8 and bypass valve 9 is Assuming that the value of the traveling wave information value one time ago is CP-1, the current time value Q of the flow rate value at the upstream end of the main water supply valve 8 and the bypass valve 9 is obtained by using the following Equations 14-1 and 14-2 as the sixth column, enter into a cell in column 16 to calculate and record the calculated value in that cell along with the formula.

Since the current flow rate values at the downstream end of the main water supply valve 8 and the bypass valve 9 are the same as the flow rate values at the upstream end of the main water supply valve 8 and the bypass valve 9, Enter the values along with formulas 14-1 and 14-2, and enter the flow rate values in the 16th column together with formulas 14-1 and 14-2 in the cells of the 18th column.
When CP ₋₁ ≧CM ₋₁ ,

In the head value spreadsheet 39, the numerical value of the initial condition is entered at the initial time (4th row), the constant head value of 10 m is entered at the upstream end (2nd column) as the boundary condition, and the downstream end (12th column) is , a constant water head value of 0 m is input. At the current time (row 5) next to the initial time, the cells of the 15th and 19th columns corresponding to the intermediate nodes 28 and 29 which are not connected ends of the pipes show forward wave information values and backward wave information values. Equation 8 and its calculated value are input and recorded as the average value of the respective values one hour before. Also, using the current time value of the previously calculated flow rate value for the 8th row cell corresponding to the downstream end of the main water supply valve 8 and the 18th row cell corresponding to the downstream end of the bypass valve 9, Equation 9 and its calculated values are entered and recorded.

In addition, the current value of the water head value at the upstream end of a pipeline with the same pipe inner diameter or pipe cross-sectional area is obtained by dividing the sound velocity in the fluid in the pipeline by the product of the pipe cross-sectional area and the gravitational acceleration. When the calculated value is the coefficient B, when the current flow rate value is calculated first, as shown in Equation 15, the backward wave information value one time before and the flow rate value at the current time It is the value obtained by adding the value multiplied by the coefficient B. That is, the current time value of the previously calculated flow rate value and backward wave information Enter and record Equation 15 using the value of 1 time ago and coefficient B, and its calculated value.

Furthermore, the current time value of the water head value at the collective branching portion (the first collective branching portion 31 and the second collective branching portion 32) provided in the pipeline is, as shown in Equations 16-1 and 16-2, For the pipelines (Pipe 1, Pipe 3, and Pipe 6) flowing into the collective branch, the value of the traveling wave information value one time before is obtained, and for the pipeline (Pipe 2, Pipe 5, and Pipe 4) flowing out from the collective branch, is the backward wave information value one time ago, divided by each coefficient B obtained by dividing the speed of sound in the fluid in the pipe by the product of the cross-sectional area of the pipe and the acceleration of gravity in the pipe, and then summed up. , and this sum is divided by the sum of the reciprocals of the respective coefficients B.

For the first branch (first branch) 31, the water head value of the aggregate branch is one time before the third column of the traveling wave information value spreadsheet 36 because the inflowing pipe 1 corresponds to the third column. is _CP3-1 , the B value in the 3rd column of the pipe specification recording spreadsheet 33 is B3, and the outflowing pipes 2 and 5 correspond to the 5th and 14th columns, so the backward wave information value spreadsheet The values one hour before in the 5th and 14th columns of 37 are _CM5-1 and _CM14-1 , and the B values in the 5th and 14th columns of the pipe specification record spreadsheet 33 are B5 and B14, and formula 16- 1 and its calculated value are entered into the cells in the 5th row of each of the 3rd, 5th and 14th columns of the head value spreadsheet 39 .

For the second collective branch (second branch) 32, the inflowing pipes 3 and 6 correspond to the ninth and twentieth rows, and the outflowing pipe 4 corresponds to the eleventh row. and tube 6, the values one hour before in the 9th and 20th columns of the traveling wave information value spreadsheet 36 are _CP9-1 and _CP20-1 , and the 9th and 20th columns of the pipe specification record spreadsheet 33 are B With respect to the outflowing pipe 4, _CM11-1 is the value one hour before in the 11th column of the backward wave information value spreadsheet 37, and B11 is the B value in the 11th column of the pipe specification record spreadsheet 33. , enter the equation 16-2 and its calculated value in the cells of the 5th row of each of the 9th, 11th and 20th columns of the head value spreadsheet 39 .

The values of the denominators of the formulas 16-1 and 16-2 are calculated and recorded in the cells of the 13th row of the corresponding columns in the pipe specification recording spreadsheet 33 of FIG. Instead of calculating, referring to line 13 of the pipe specification record spreadsheet 33 simplifies the calculation of the formula. These formulas 16-1 and 16-2 are the values of the advancing wave information value spreadsheet 36 one time before for the inflowing tube row, and the backward wave information value one time value of the backward wave information value spreadsheet 37 for the outflowing tube row. It is a mathematical formula in which the sum of the values obtained by dividing the previous value by the B value of each column is the numerator, and the sum of the reciprocals of the B values of the corresponding column is the denominator. Calculate the water head value at the current time.

By copying the formulas entered in the fifth row of the flow rate value spreadsheet 38 and the head value spreadsheet 39 to the cells on the sixth and subsequent lines, the time histories of the flow rate value and the head value can be obtained. 15 and 16 show examples of analysis results analyzed in this way. In this example, as shown in FIG. 12, in the time history of the Cv (Cv1, Cv2) values of the main water valve 8 and the bypass valve 9, the main water valve 8 starts closing at 0.4 seconds. The bypass valve 9 is fully closed in 1 second, and the bypass valve 9 starts to open at 0.5 seconds and is fully open in 0.6 seconds.

In the flow diagram shown in FIG. 15, the second column corresponding to the upstream end of the flow rate value spreadsheet 38 is the upstream end flow rate, the sixth column corresponding to the upstream end of the main water valve 8 is the main water pipe flow rate, and the bypass valve The 16th column corresponding to the upstream end of 9 is the bypass pipe flow rate, and each time history is shown. The hydraulic head chart shown in FIG. 16 shows the time history of the sixth column corresponding to the upstream end of the main water valve 8 and the sixteenth column corresponding to the upstream end of the bypass valve 9 of the hydraulic head value spreadsheet 39. . It can be seen that the flow rate is smoothly switched from the main water pipe 26 to the bypass pipe 27, but the water head vibrates after the water head at the upstream end of the main water valve 8 rises greatly, causing a water hammer phenomenon. I understand.

Since it is configured as described above, the second embodiment also has the following effect (2), similar to the effect (1) of the first embodiment.
(2) According to the water hammer analysis device 25, the water hammer analysis parameter information spreadsheet 34 (traveling wave information value spreadsheet 36, receding wave information value spreadsheet 37, flow rate value spreadsheet 38, water head value spreadsheet 39) Formulas for water hammer analysis and numerical values determined by these formulas are entered and recorded in the cells. For this reason, the water hammer analysis parameter information spreadsheet 34 (advancing wave information value spreadsheet 36, receding wave information value spreadsheet 37, flow rate value spreadsheet 38, water head value spreadsheet 39) clearly indicates all the analysis processes of the water hammer phenomenon. Therefore, by comparing the formulas entered in each row of the same column of the water hammer analysis parameter information spreadsheet 34, it is possible to determine whether the water hammer phenomenon has been correctly analyzed without using a special program language. Easy to verify.

In addition, the numerical values recorded in the cells of the water hammer analysis parameter information spreadsheet (traveling wave information value spreadsheet 36, receding wave information value spreadsheet 37, flow rate value spreadsheet 38, water head value spreadsheet 39) are graphed and waveform By displaying with , the validity of the analysis result by the water hammer analysis device 25 can be easily confirmed.

[C] Third embodiment (Figs. 17 to 24)
FIG. 17 is a block diagram showing the configuration of a water hammer analysis device according to the third embodiment. In the third embodiment, the same parts as those in the first and second embodiments are denoted by the same reference numerals as those in the first and second embodiments, thereby simplifying or omitting the description.

The water hammer analysis device 43 of the third embodiment analyzes a water hammer phenomenon accompanied by a water column separation phenomenon. In general, when the fluid is a liquid such as water, when the pressure of the fluid is reduced to below the steam head (steam head + pipe height), boiling under reduced pressure occurs. A vapor cavity is created. This phenomenon is known as the water column separation phenomenon in water hammer, and when the head of the fluid recovers more than the head of the steam head, the steam cavity disappears, and a shocking rise in the head of water is observed at this time.

The water hammer analysis device 43 analyzes the water hammer phenomenon accompanied by the water column separation phenomenon as described above. A steam production spreadsheet 45 is additionally provided as production storage means.

That is, the water hammer analysis device 43 has a pipe specification record spreadsheet 11 or 33, a water hammer analysis parameter information spreadsheet 46 as a water hammer analysis parameter information storage means, and a calculation means 47, and the water hammer analysis parameter The information spreadsheet 46 includes the traveling wave information value spreadsheet 14 or 36, the backward wave information value spreadsheet 15 or 37, the flow value spreadsheet 16 or 38, the decompression flag spreadsheet 44, the vapor production rate spreadsheet 45, and A head value spreadsheet 48 is provided as a head value recording means. Each of these spreadsheets 14(36), 15(37), 16(38), 44, 45, 48 stores calculation means 47 which will be detailed later.

19A, the backward wave information value spreadsheet 15 or 37 shown in FIG. 19B, and the flow rate value spreadsheet 16 or 38 shown in FIG. , the formulas of the first or second embodiment that do not involve the water column separation phenomenon are input. In addition, the current time value of the temporary head value of each part in the pipeline in the analysis of the water hammer phenomenon accompanied by the water column separation phenomenon is the formula (formula 8, Equations 10 and 15).

As shown in FIGS. 20(C), 20(D) and 21(F), the decompression flag spreadsheet 44, the steam production amount spreadsheet 45 and the head value spreadsheet 48 are different from those of the first and second embodiments. Similarly, each portion of the pipeline obtained by virtually dividing the pipeline in the axial direction is set in the column direction, and the time axis is set in the row direction. In each of the pressure reduction flag spreadsheet 44, the steam production amount spreadsheet 45, and the water head value spreadsheet 48, the initial conditions are set at the initial time in the 4th row, and the analysis time increment is set to 0.1 in each row after the 5th row. The time in seconds is set, and the time histories of the value of the decompression flag, the amount of steam generated, and the water head value are recorded in the cells of each row from the fifth row onward, together with mathematical formulas as the calculation means 47, which will be described later.

In the decompression flag spreadsheet 44 shown in FIG. 20(C), when the water hammer phenomenon is accompanied by the water column separation phenomenon, the water head value of each part in the pipeline is equivalent to the steam head (that is, the steam head + pipe height) or less. The time history of the decompression flag is recorded using the decompression flag indicating this as water hammer analysis parameter information. The current time value of the decompression flag of each section in the pipeline recorded in this decompression flag spreadsheet 44 is the value of the decompression flag one time ago, the current time value of the temporary head value, and the pipe height of the relevant section of the pipeline. It is calculated by the flow chart shown in FIG. 22 based on a predetermined algorithm, using the steam head considering the heat and the current time value of the amount of steam generated.

For the decompression flag spreadsheet 44, the cells in which the initial conditions at the initial time (fourth row) and the boundary conditions (second column) where the head value is specified are pre-populated with numerical values (usually no vapor cavity 0) is specified and recorded. In the other cells (except for the empty rows between the tubes on the decompression flag spreadsheet 44), the formulas defining the flow chart shown in FIG. 22 and the numerical values (0 or 1) according to this flow chart are entered and recorded. . The formulas defining this flow chart constitute the calculation means 47 for the decompression flag spreadsheet 44 .

In the flowchart shown in FIG. 22, it is determined whether or not the value of the decompression flag (ICAV) one time ago is 0 (S11). When the value of the decompression flag one time ago is 0 and "no decompression", then the current time value of the temporary head value is below the steam head (steam head + pipe height) considering the pipe height. It is determined whether or not there is (S12). In this step S12, when it is determined that the current time value of the temporary head value is equal to or less than "steam head + pipe height", the current time value of the decompression flag is set to 1 to display "with decompression" ( S13) If the above is the case, the current time value of the decompression flag is set to 0 and "no decompression" is displayed (S14).

In step S11, if it is determined that the value of the decompression flag one time ago is 1 and the water column separation phenomenon is occurring, then it is determined whether the current value of the steam generation amount (VCAV) is a positive value. It judges (S15). If the current time value of the steam generation amount is 0 or a negative value in step S15, the current time value of the decompression flag is set to 0 to display "no decompression" (S14). , the current time value of the decompression flag is set to 1, and "with decompression" is displayed (S16).

Here, ICAV in FIG. 22 and the flow charts of FIGS. VCAV represents steam production and is the value of the appropriate cell of steam production spreadsheet 45 . H represents the head value and is the value of the appropriate cell in the head value spreadsheet 48 . In addition, the provisional head value is the head value calculated by Equation 7, Equation 8, or Equation 15 described in the cells of the head value spreadsheets 17 and 39 when the water column separation phenomenon in the first and second embodiments is not considered. is. Further, the pipe height refers to the height from the reference surface at the relevant portion of the pipe.

In the steam generation amount spreadsheet 45 shown in FIG. 20(D), when the water hammer phenomenon accompanies the water column separation phenomenon, the water head value of each part in the pipeline is equal to or less than the steam head (steam head + pipe height). The time history of the amount of steam generated is recorded as water hammer analysis parameter information. The current time value of the steam generation amount of each part in the pipeline recorded in this steam generation amount spreadsheet 45 is the value of the pressure reduction flag one hour ago, the current time value of the temporary water head value, and the one time value of the steam generation amount. Based on a predetermined algorithm using the previous value, the value of the forward wave information value one time ago, the backward wave information value one time ago, and the steam head considering the pipe height of the relevant part of the pipeline It is calculated by the flowchart shown in FIG. 23 (including formulas 17-1, 17-2, 17-3 and 17-4).

In this steam production spreadsheet 45 as well, the cells in which the initial conditions at the initial time (fourth row) and the boundary conditions (second column) specifying the water head value are entered are numerical values (usually the steam production 0) is specified and recorded. All other cells (except the empty rows between tubes in the steam production spreadsheet 45) contain the formulas defining the flow chart shown in FIG. , 17-3, 17-4) is entered and recorded. The formulas defining the above flow chart, including formulas 17-1, 17-2, 17-3, and 17-4, constitute the calculation means 47 for the steam production spreadsheet 45 .

In the flowchart shown in FIG. 23, it is determined whether or not the value of the decompression flag (ICAV) one time ago is 0 (S21). When the value of the decompression flag one time ago is 0 and "no decompression", then the current time value of the temporary head value is below the steam head (steam head + pipe height) considering the pipe height. It is determined whether or not there is (S22). In this step S22, when it is determined that the current time value of the provisional water head value is equal to or less than "steam head + pipe height", the current time value of the steam generation amount (VCAV) is set to Equations 17-1 and 17 below. -2, is calculated and set by Equation 17-3 or Equation 17-4 (S23), and if it is determined that the above is satisfied, the current time value of the steam generation amount is set to 0 (S24).

In step S21, if it is determined that the value of the decompression flag one time ago is 1 and the water column separation phenomenon is occurring, then the current time value of the amount of steam generated (VCAV) is calculated by Equations 17-1 and 17- 2. Calculation is performed based on Equation 17-3 or Equation 17-4, and it is determined whether or not the calculated value is a positive value (S25). If the current time value of the steam generation amount is 0 or a negative value in step S25, the current time value of the steam generation amount is set to 0 (S24). , is set to the value calculated in step S25 (S26).

Equations 17-1, 17-2, 17-3, and 17-4 will now be described.
Assuming that the value of the steam generation amount before one hour in the cell is VCAV _-1 , the current time value VCAV of the steam generation amount is the analysis time step dt and the coefficient B recorded in the pipe specification recording spreadsheet 11 or 33. , using the advancing wave information value one time ago value CP ₋₁ and the backward wave information value one time ago value CM ₋₁ ,
If the cell is specified at the upstream connection end of the pipeline,

The water head value spreadsheet 48 shown in FIG. 21(F) records the current time value of the water head value of each part in the pipeline when the water hammer phenomenon accompanied by the water column separation phenomenon occurs in the pipeline. The current time value of this water head value is the value of the decompression flag one time ago, the current time value of the temporary water head value, the value of the traveling wave information value one time ago, the value of the backward wave information value one time ago, and the pipe 24 based on a predetermined algorithm (including equations 18-1, 18-2, 18-3 and 18-4 ).

With respect to the head value spreadsheet 48, numerical values are entered in the cells where the initial conditions at the initial time (fourth row) and the boundary conditions (second column) where the head value is specified are entered. All other cells (except the empty columns between tubes in the head value spreadsheet 48) contain formulas defining the flow chart shown in FIG. Value calculated by Equation 8 or Equation 15”, or “Water head rise value ΔH at the time of disappearance (at the time of recombination) of the steam cavity calculated by Equation 18-1, 18-2, 18-3 or 18-4” A value obtained by adding the value of "water head + pipe height" is entered and recorded. The formulas defining the above flow chart, including formulas 7, 8, 15, 18-1, 18-2, 18-3 and 18-4, constitute the calculation means 47 for the head value spreadsheet 48 .

In the flowchart shown in FIG. 24, it is determined whether or not the value of the decompression flag (ICAV) one time ago is 0 (S31). When the value of the decompression flag one time ago is 0 and "no decompression", then the current time value of the temporary head value is below the steam head (steam head + pipe height) considering the pipe height. It is determined whether or not there is (S32). In this step S32, when it is determined that the current time value of the temporary head value is equal to or less than "steam head + pipe height", the current time value of the water head value is set to "steam head + pipe height" ( S33), if the above, the current time value of the water head value is set as the temporary water head value (S34).

In step S31, if it is determined that the value of the decompression flag one time ago is 1 and the water column separation phenomenon is occurring, then it is determined whether the current value of the steam generation amount (VCAV) is 0 or a negative value. (S35). In this step S35, if the current time value of the steam generation amount is a positive value, it is determined that steam is being generated, and the current time value of the steam generation amount is set to "steam head + pipe height" (S37). ), and if it is 0 or a negative value, it is determined that the steam cavity has collapsed, and the current time value of the steam generation amount is set to "steam head + pipe height + ΔH" (S36). ΔH is a value calculated by Equation 18-1, Equation 18-2, Equation 18-3, or Equation 18-4.

Equations 18-1, 18-2, 18-3, and 18-4 will now be described.
The current time value ΔH of the head rise value at the time of recombination in the cell is obtained from the sound velocity a recorded in the pipe specification recording spreadsheet 11 or 33, the pipe cross-sectional area A, the coefficient B, and the traveling wave information value at one time Using the previous value CP ₋₁ , the backward wave information value 1 time ago value CM ₋₁ , and the gravitational acceleration g,
If the cell is the upstream connection end (closed) of the pipeline,

Due to the configuration as described above, the third embodiment also has the following effect (3) as in the first and second embodiments.
(3) According to the water hammer analysis device 43, the water hammer analysis parameter information spreadsheet 46 (traveling wave information value spreadsheet 14 or 36, receding wave information value spreadsheet 15 or 37, flow rate value spreadsheet 16 or 38, decompression Formulas for water hammer analysis and numerical values determined by these formulas are entered and recorded in the cells of the flag spreadsheet 44, the steam production amount spreadsheet 45, and the head value spreadsheet 48). For this reason, the water hammer analysis parameter information spreadsheet 46 (traveling wave information value spreadsheet 14 or 36, receding wave information value spreadsheet 15 or 37, flow rate value spreadsheet 16 or 38, decompression flag spreadsheet 44, steam production amount spreadsheet Since the analysis process of the water hammer phenomenon accompanied by the water column separation phenomenon is clearly shown in the sheet 45 and the water head value spreadsheet 48), the formulas entered in each row of the same column of this water hammer analysis parameter information spreadsheet 46 are compared. By doing so, it is possible to easily verify whether the analysis of the water hammer phenomenon accompanied by the water column separation phenomenon was correctly performed without using a special program language.

Also, water hammer analysis parameter information spreadsheet 46 (advancing wave information value spreadsheet 14 or 36, receding wave information value spreadsheet 15 or 37, flow rate value spreadsheet 16 or 38, decompression flag spreadsheet 44, steam generation amount spreadsheet 45, By graphing the numerical values recorded in the cells of the water head value spreadsheet 48) and representing them as waveforms, the validity of the analysis results by the water hammer analysis device 43 can be easily confirmed.

Although several embodiments of the invention have been described above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention, and these replacements and changes can be made. is included in the scope and gist of the invention, and is included in the scope of the invention described in the claims and its equivalents.

For example, in each spreadsheet in the first to third embodiments, each part in the pipeline is set in the column direction and the time axis is set in the row direction, but each part in the pipeline is set in the row direction, A time axis may be set in the column direction, and the formula may be copied in the cell in the column direction in which the time history of the water hammer analysis parameter information is recorded. Further, the calculation formulas (formulas) of the calculation means 13, 35, and 47 in each embodiment can be displayed on the display means 18 instead of the spreadsheets 14 to 17, 36 to 39, 44, 45, and 48. Therefore, the analysis of the water hammer phenomenon can be easily verified by comparing these formulas.

8... Main water supply valve (concentrated pressure loss part), 9... Bypass valve (concentrated pressure loss part), 10... Water hammer analysis device, 11... Pipe specification recording spreadsheet (pipe specification information recording means), 12... Water hammer analysis Parameter information spreadsheet (water hammer analysis parameter information recording means) 13 Calculation means 14 Traveling wave information value spreadsheet (traveling wave information value recording means) 15 Backward wave information value spreadsheet (backward wave information value recording means), 16... Flow rate value spreadsheet (flow rate value recording means), 17... Head value spreadsheet (head value recording means), 20... Pipe line, 21... Terminal valve (concentrated pressure loss part)

25 Water hammer analysis device 26 Main water pipe 27 Bypass pipe 31 First branching unit 32 Second branching unit 33 Pipe specification recording spreadsheet (pipe specification information recording means) 34 ... water hammer analysis parameter information spreadsheet (water hammer analysis parameter information recording means), 35 ... calculation means, 36 ... traveling wave information value spreadsheet (traveling wave information value recording means), 37 ... backward wave information value spreadsheet (backward Wave information value recording means), 38 Flow value spreadsheet (flow value recording means), 39 Head value spreadsheet (head value recording means), 43 Water hammer analysis device, 44 Decompression flag spreadsheet (decompression flag recording Means), 45... Steam production amount spreadsheet (steam production amount recording means), 46... Water hammer analysis parameter information spreadsheet (water hammer analysis parameter information recording means), 47... Calculation means, 48... Water head value spreadsheet (water head value recording means)

Claims (14)

In a water hammer analysis device that analyzes the water hammer phenomenon caused by changes in the hydraulic head and flow rate of the fluid in the pipeline,
pipe specification information recording means for recording pipe specification information of each part of the pipe;
Water hammer analysis parameter information recording means for recording time history of water hammer analysis parameter information including water head and flow rate at each part in the pipeline;
calculation means for calculating the current time value of the water hammer analysis parameter information by a formula using the value of the pipe specification information and the previous time value of the water hammer analysis parameter information;
display means capable of displaying the calculation formula of the calculation means relating to different times;
A water hammer analysis device characterized by comprising: The water hammer analysis parameter information recording means includes head value recording means for recording the time history of the water head value at each part in the pipeline as the time history of the water hammer analysis parameter information, and the time of the flow rate value at each part in the pipeline. a flow rate value recording means for recording the history as a time history of water hammer analysis parameter information; A traveling wave information value recording means for recording information as a time history; and a backward wave information value recording means for recording as
Furthermore, in the case of a water hammer accompanied by a water column separation phenomenon, the time history of the decompression flag indicating that the water head value of each part in the pipeline is equal to or less than the steam head is recorded as the time history of the water hammer analysis parameter information Decompression flag recording means; and steam generation amount recording means for recording, as a time history of the water hammer analysis parameter information, the time history of the amount of steam generated when the water head value of each part in the pipeline is equal to or less than the steam head. The water hammer analysis device according to claim 1, further comprising: The pipe specification information recording means and the water hammer analysis parameter information recording means are spreadsheet software spreadsheets having a plurality of cells set by a plurality of rows and columns,
In the spreadsheet of the pipe specification information recording means, pipe parts obtained by virtually dividing the pipe in the axial direction are set in the column direction, pipe specification information is set in the row direction, and the pipe pipe is stored in each cell. The value of the pipe specification information for each part is recorded,
In the spreadsheet of the water hammer analysis parameter information recording means, each part of the pipeline obtained by virtually dividing the pipeline in the axial direction is set in the column direction, and the time of the water hammer analysis parameter information is set in the row direction. A time history of the water hammer analysis parameter information of each part of the pipeline is recorded in each cell,
The calculation formula of the calculation means is input and recorded in the cell that records the current time value of the water hammer analysis parameter information in the spreadsheet of the water hammer analysis parameter information recording means, and the water hammer analysis parameter information 3. The water hammer analysis device according to claim 1, wherein the formula is a formula for calculating a current time value. In each spreadsheet of the pipe specification information recording means and the water hammer analysis parameter information recording means, the information of each part in the pipeline is arranged in the row direction for each part of the pipeline with the same inner diameter or cross-sectional area. Consecutively recorded, different diameter pipe connection portions having different inner diameters or cross-sectional areas of the pipe, concentrated pressure loss portions provided in the pipe, or collecting and branching portions provided in the pipe are spaced apart in the row direction. 4. The water hammer analysis device according to claim 3, wherein the water hammer analysis device is configured to be recorded at intervals. The pipe specification recording information recorded in the pipe specification information recording means includes a ratio obtained by dividing the analysis time step value by the virtual division length when the pipe is virtually divided in the axial direction, 5. A water hammer analysis apparatus according to claim 1, wherein a value obtained by multiplying the speed of sound in the fluid is recorded as a coefficient .zeta., and the coefficient .zeta. is set to 1 or less. The traveling wave information value of each part in the pipeline is calculated using the simultaneous values of the head value and the flow rate value of the same row and the simultaneous values of the water head value and the flow value of the adjacent upstream row. The water hammer analysis device according to any one of claims 2 to 5, characterized by: The backward wave information value of each part in the pipeline is calculated using the simultaneous values of the water head value and the flow rate value of the same row and the simultaneous values of the water head value and the flow value of the adjacent downstream row. The water hammer analysis device according to any one of claims 2 to 6, characterized by: The current value of the hydraulic head value of each part in the pipeline, or the current value of the temporary hydraulic head value of each part in the pipeline in the case of a water hammer accompanied by a water column separation phenomenon, is the pipe with the same inner diameter or cross-sectional area In a pipe line portion other than the pipe end portion of the pipe, it is an average value obtained by dividing the sum of the value of the forward wave information one time ago and the value of the backward wave information one time ago by 2,
At the upper end of the pipe having the same inner diameter or cross-sectional area, the coefficient B is the value obtained by dividing the sound velocity in the fluid in the pipe by the product of the cross-sectional area of the pipe and the gravitational acceleration. is a value obtained by adding a value obtained by multiplying the current time value of the flow rate value by the coefficient B to the value of the backward wave information value one time before when the current time value of the value is calculated first,
At the lower end of the pipeline having the same inner diameter or cross-sectional area, when the current flow rate value is calculated first, the traveling wave information value of one time before is changed to the current flow rate value. The water hammer analysis device according to any one of claims 2 to 7, wherein the value is a value obtained by subtracting a value multiplied by the coefficient B. The current value of the amount of steam generated at each part in the pipeline is the value of the pressure reduction flag one hour ago, the current value of the temporary water head value, the value of the amount of steam generated one hour ago, and the traveling wave information value. It is characterized in that it is calculated based on a predetermined algorithm using the value one time ago, the backward wave information value one time ago, and the steam head considering the pipe height of the relevant part of the pipe. The water hammer analysis device according to claim 8. The current time value of the decompression flag of each section in the pipeline is the value of the decompression flag one time ago, the current time value of the temporary head value, and the steam head considering the pipe height of the relevant section of the pipeline. 10. The water hammer analysis device according to claim 8 or 9, wherein the water hammer analysis apparatus is calculated based on a predetermined algorithm using the current time value of the amount of steam generated. In the case of a water hammer accompanied by a water column separation phenomenon in the pipeline, the current time value of the hydraulic head value of each part in the pipeline is the value of the decompression flag one time ago, the current time value of the temporary hydraulic head value, and the traveling wave It is calculated based on a predetermined algorithm using the value of the information value one hour ago, the value of the backward wave information value one hour ago, and the steam head considering the pipe height of the relevant part of the pipe. A water hammer analysis device according to any one of claims 8 to 10. The current flow rate value of each part in the pipeline is obtained by subtracting the current head value from the traveling wave information value one time before when the current head value is calculated first. is a value obtained by dividing the sound velocity in the fluid in the pipeline by a coefficient B obtained by dividing the product of the cross-sectional area in the pipeline and the gravitational acceleration, or backward wave information from the current time value of the water head value 12. The water hammer analysis device according to any one of claims 2 to 11, wherein the value obtained by subtracting the value of the value one time before is divided by the coefficient B. The current time value of the flow rate value of the fluid passing through the concentrated pressure loss section provided in the pipeline is the Cv value that indicates the relationship between the flow rate and the head difference in the concentrated pressure loss section, and the The value of the upstream traveling wave information value one time before, the value of the backward wave information value downstream of the concentrated pressure loss portion one time before, and the value of the backward wave information value on the upstream side of the concentrated pressure loss portion in the pipeline A coefficient B1 obtained by dividing the speed of sound in the fluid by the product of the cross-sectional area in the upstream pipe and the acceleration of gravity, and the speed of sound in the fluid in the pipe on the downstream side with respect to the concentrated pressure loss portion 13. The water hammer analysis device according to any one of claims 2 to 12, wherein the coefficient B2 is divided by the product of the cross-sectional area in the pipeline and the acceleration of gravity. The present time value of the water head value at the collecting and branching portion provided in the pipe line is the value of the traveling wave information value one time before for the pipe line flowing into the collecting and branching portion, and For the channels, the backward wave information value one time before is divided by the product of the cross-sectional area in each channel and the gravitational acceleration, the sound velocity in the fluid in the channel flowing in or out, respectively, by the coefficient B 14. The water hammer analysis device according to any one of claims 2 to 13, wherein a sum is taken after division, and the sum is divided by a sum of reciprocals of the respective coefficients B.

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