KR102545782B1 - Automatic flow calculation device through loss head measurement - Google Patents

Abstract

The present invention relates to an automatic device for calculating flow rate through head loss measurement, and more particularly, to measure head loss in a circuit unit by a pressure value measured by a pressure sensor unit, and to measure head loss and temperature sensor unit in the measured head loss and temperature sensor unit. By collecting the measured temperature values and calculating the flow rate through the flow calculation algorithm, it is possible to measure the actual flow rate of the discharge amount generated by the hydroelectric power plant, so it is convenient to integrate hydrologic data and manage statistical data, and to quickly determine the performance and aging of the generator. As a result, the purification of hydrological data in the field of water resources is improved.

Description

Automatic flow calculation device through loss head measurement}

The present invention relates to an automatic device for calculating flow rate through head loss measurement, and more particularly, to measure head loss in a circuit unit by a pressure value measured by a pressure sensor unit, and to measure head loss and temperature sensor unit in the measured head loss and temperature sensor unit. By collecting the measured temperature values and calculating the flow rate through the flow calculation algorithm, it is possible to measure the actual flow rate of the discharge amount generated by the hydroelectric power plant, so it is convenient to integrate hydrologic data and manage statistical data, and to quickly determine the performance and aging of the generator. Accordingly, it relates to an automatic flow calculation device through measurement of head loss, which improves the purification of hydrological data in the field of water resources.

Among the hydrological data in the field of water resources, the amount of discharge generated by hydroelectric power plants (large hydro and small hydro) is managed based on estimates based on power generation output, not actual flow rates, making it difficult to integrate hydrological data and manage statistical data.

In addition, the amount of discharge generated by hydroelectric power generators does not reflect the conditions caused by aging and degradation of the generator by applying the discharge amount conversion value according to the power generation output, not the actual measured value.

In the case of invalid discharge downstream of the dam, it was difficult to confirm the accurate actual flow rate by applying the estimated value according to the discharge valve opening and water level.

As such, the amount of discharge among hydrological data in the field of water resources is managed as an estimated value rather than an actual flow rate, so there are always difficulties in accurately integrating hydrological data and managing statistical data.

In addition, the generation discharge amount is applied by a conversion value according to the generation output, not actual measurement, and does not reflect the change in discharge amount when the generator deteriorates and deteriorates. It is difficult to check the discharge amount.

Republic of Korea Patent Publication No. 10-2015-0008444

The present invention has been made to solve the above conventional problems,

By measuring the head loss in the circuit part by the pressure value measured by the pressure sensor unit, and by collecting the measured head loss and the temperature value measured by the temperature sensor unit and calculating the flow rate value through a flow calculation algorithm, a hydroelectric power plant It is possible to measure the actual flow rate of power generation discharge, so it is convenient to accumulate hydrologic data and manage statistical data, and it is possible to quickly judge the performance and aging of the generator, thereby improving the purification of hydrological data in the field of water resources. The purpose is to provide an automatic computing device.

In order to achieve the above object, the present invention is a device for automatically calculating the discharged flow rate installed in the discharge pipe of a hydroelectric power plant,

a body part;

a pressure sensor unit connected to the main body and installed through the discharge pipe to measure the pressure of the fluid discharged from the discharge pipe;

a temperature sensor unit connected to the main body and installed through the discharge pipe to measure the temperature of the fluid discharged from the discharge pipe;

The head loss in the discharge pipe is measured by the pressure value measured by the pressure sensor installed inside the main body, and the measured head loss and the temperature value measured by the temperature sensor are combined to calculate the flow rate through an algorithm. a circuit unit that calculates a flow rate value;

a display unit installed in the main body unit, connected to the circuit unit, and displaying a pressure value, a temperature value, and a flow rate value collected in the circuit unit;

It relates to an automatic flow calculation device through measurement of head loss, characterized in that it is configured to include.

In addition, the main body of the present invention relates to a device for automatically calculating flow rate through head loss measurement, characterized in that a communication unit for transmitting and receiving data of the circuit unit is connected to the circuit unit.

In addition, head loss measurement characterized in that a waterproof cover is further installed on one side of the main body where the display of the present invention is installed to prevent fluid from flowing into the display, and one side of the waterproof cover is formed transparent to identify the display. It relates to an automatic flow calculation device through.

In addition, the flow rate calculation algorithm of the circuit part of the present invention is Equation 1-10 and Colebrook-White substituting Equation 1-9 derived from Equation 1-4 and Darcy-Weisbach Equation below derived from Bernoulli's theorem It relates to an automatic flow calculation device through head loss measurement, characterized in that the head loss is derived by the following Equation 1-11 derived from the equation.

In addition, the flow calculation algorithm of the circuit part of the present invention relates to an automatic device for calculating flow rate through head loss measurement, characterized in that the flow rate and friction coefficient of Equations 1-10 and Equation 1-11 are derived by the Newton iterative method. .

As described above, the automatic flow calculation device through the measurement of the head loss of the present invention measures the head loss in the circuit unit by the pressure value measured by the pressure sensor unit, and measures the head loss in the measured head loss and the temperature sensor unit. By collecting the measured temperature values and calculating the flow rate through the flow calculation algorithm, it is possible to measure the actual flow rate of the discharge amount generated by the hydroelectric power plant, so it is convenient to integrate hydrologic data and manage statistical data, and to quickly determine the performance and aging of the generator. Thereby, there is an effect of improving the purification of hydrological data in the field of water resources.

1 is a schematic diagram showing an automatic flow calculation device installed in an outlet pipe according to an embodiment of the present invention;
2 is an exploded perspective view showing an automatic flow calculation device according to an embodiment of the present invention;
3 is a front view showing an automatic flow calculation device according to an embodiment of the present invention;
4 is a side view showing a main body according to an embodiment of the present invention;
5 is a schematic diagram showing a valve and a pressure gauge installed at the downstream end part according to an embodiment of the present invention;
6A to 6C are document diagrams showing a test report of an automatic flow calculation device according to an embodiment of the present invention.

The present invention having such characteristics will be more clearly explained through the preferred embodiments thereof.

Before describing various embodiments of the present invention in detail with reference to the accompanying drawings, it will be appreciated that the application is not limited to the details of the configuration and arrangement of components described in the following detailed description or shown in the drawings. will be. The invention is capable of being implemented and practiced in other embodiments and of being carried out in various ways. Also, device or element orientation (e.g., "front", "back", "up", "down", "top", "bottom") The expressions and predicates used herein with respect to terms such as ", "left", "right", "lateral", etc. are only used to simplify the description of the present invention and related devices. Or it will be appreciated that it does not indicate or imply that an element simply must have a particular orientation. Also, terms such as "first" and "second" are used herein and in the appended claims for descriptive purposes and are not intended to indicate or imply relative importance or significance.

Therefore, since the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, various alternatives may be used at the time of this application. It should be understood that there may be equivalents and variations.

1 is a schematic diagram showing an automatic flow calculation device installed in an outlet pipe according to an embodiment of the present invention, FIG. 2 is an exploded perspective view showing an automatic flow calculation device according to an embodiment of the present invention, and FIG. It is a front view showing an automatic flow calculation device according to an embodiment of the present invention, Figure 4 is a side view showing a main body according to an embodiment of the present invention, Figure 5 is installed at the downstream end according to an embodiment of the present invention It is a schematic diagram showing a valve and a pressure gauge, and FIGS. 6A to 6C are document diagrams showing a test report of an automatic flow calculator according to an embodiment of the present invention.

As shown in FIGS. 1 to 5, the automatic flow calculation device 100 through the measurement of the head loss of the present invention includes a body portion 10; A pressure sensor unit 20 connected to the main body 10, installed through the discharge pipe 1, and measuring the pressure of the fluid discharged from the discharge pipe 1; A temperature sensor unit 30 connected to the main body 10, installed through the discharge pipe 1, and measuring the temperature of the fluid discharged from the discharge pipe 1; The head loss in the discharge pipe 1 is measured by the pressure value measured by the pressure sensor unit 20 installed inside the main body unit 10, and the measured head loss and temperature sensor unit 30 a circuit unit 40 that collects the temperature values measured in and calculates a flow rate value through a flow calculation algorithm; It is installed on the body part 10 and is connected to the circuit part 40, and is configured to include a display part 50 that displays the pressure value, temperature value and flow rate value collected in the circuit part 40.

As shown in FIGS. 1 to 4, the body portion 10 has a hollow interior and is provided with a circuit portion 40, and the body portion 10 has a fastener at the bottom so as to be installed around the discharge pipe 1. (11) is further formed.

Here, a plurality of connectors 12 are formed on both sides of the body unit 10 to be connected to the pressure sensor unit 20 or the temperature sensor unit 30 or the communication unit 60, and the connectors 12 Through this, the pressure sensor unit 20 or the temperature sensor unit 30 or the communication unit 60 is connected to the circuit unit 40 provided inside the body unit 10 . At this time, the communication unit 60 is connected to the circuit unit 40 by a communication line to transmit and receive data of the circuit unit 40 .

In addition, an installation hole 13 is formed on the front surface of the body portion 10 to install the display unit 50, and the display unit 50 installed in the installation hole 13 of the body portion 10 is a circuit unit ( 40) and data collected by the circuit unit 40 is displayed.

In addition, a waterproof cover part 14 is further installed in the installation hole 13 where the display part 50 is installed to prevent fluid from flowing into the display part 50, and one surface of the waterproof cover part 14 is The display unit 50 is formed transparently to be identified.

As shown in FIGS. 1 to 3, the pressure sensor unit 20 is installed through the inside of the discharge pipe 1 in a state connected to the connector 12 of the body unit 10 by a connection line, and the The pressure of the fluid discharged from the discharge pipe 1 is measured and transmitted to the circuit unit 40 .

As shown in FIGS. 1 to 3, the temperature sensor unit 30 is installed through the inside of the discharge pipe 1 in a state connected to the connector 12 of the main body 10 by a connection line, and the discharge pipe 1 The temperature of the fluid discharged from the pipe 1 is measured and transmitted to the circuit unit 40.

As shown in FIGS. 1 to 3 , the display unit 50 is installed in the installation hole 13 of the body unit 10 and is connected to the circuit unit 40, and the pressure value collected in the circuit unit 40 , temperature value and flow rate value are displayed to provide information.

As shown in FIGS. 1 to 5, the circuit part 40 is installed inside the main body part 10 and measures the head loss in the discharge pipe 1 by the pressure value measured by the pressure sensor part 20. The measured head loss and the temperature value measured by the temperature sensor unit 30 are collected to calculate the flow rate value through a flow calculation algorithm.

Hereinafter, the flow calculation algorithm of the circuit unit 40 will be described with reference to equations and drawings.

1.1 Flow measurement principle of loss head type flow meter

If the completely closed state of the valve in the pipe shown in FIG. 5 is derived from the Bernoulli equation as follows,

[Equation 1-1]

When the valve is open and flow occurs,

[Equation 1-2]

Rewriting Equation 1-1 and Equation 1-2 above as one,

[Equation 1-3]

= 0이고 압력계의 높이

이므로 수학식 1-4는 하기와 같이 쓸 수 있다.When the valve is fully closed

= 0 and the height of the pressure gauge

Therefore, Equations 1-4 can be written as follows.

[Equation 1-4]

:손실수두이다.Here, P: fluid pressure, r: fluid density, V: average flow velocity, g: gravitational acceleration, A: cross-sectional area of the pipe

: is the loss head.

1.2 Pipe loss head

라 도출하고, 유동이 형성될 때 관로 특정 지점에서의 수두

는 이

에서 관로 내 관로 표면과 유체와의 마찰에 의한 마찰손실

그리고 밸브, 곡관 등에서 유동교란에 의해 손실되는 미소손실

을 감한 수두와 동일하다는 것이다.The loss head type flow measurement principle is the hydrostatic head formed when the flow in the pipe is stopped.

, and the head at a specific point in the pipeline when the flow is formed

is this

Friction loss due to friction between the surface of the pipe and the fluid in the pipe

In addition, minute losses due to flow disturbance in valves, bends, etc.

It is equivalent to chickenpox minus .

[Equation 1-5]

: 유동이 정지된 상태에서 수두,

: 유동이 형성된 상태에서 수두,

: 관로 내 마찰손실수두,

: 관로 내 미소손실수두,

: 관로 내 손실수두이다.here,

: head in a state where the flow is stopped,

: head in the state where the flow is formed,

: Head of friction loss in the pipeline,

: Minimal head loss in the pipeline,

: is the head loss in the pipeline.

와 미소손실수두

을 하기와 같이 구할 수 있다.Head friction loss by Darcy-Weisbach equation

and small loss head

can be obtained as follows.

[Equation 1-6]

[Equation 1-7]

: 마찰계수, L : 관로 길이, D : 관로 직경, V : 관로 내 평균 유속, g : 중력가속도,

: 각종 손실계수, A : 관로의 단면적이다.here,

: Friction coefficient, L : Pipe length, D : Pipe diameter, V : Average flow velocity in the pipe, g : Gravitational acceleration,

: Various loss coefficients, A: Cross-sectional area of the pipeline.

은 하기와 같다.And, the total number of losses

is as follows.

[Equation 1-8]

이 증가하는 것을 알 수 있다.In this way, Equations 1-6 to 1-8 are summarized as follows, and as the flow rate Q increases,

It can be seen that this increases

[Equation 1-9]

로 표시하고,

이므로 수학식 1-4에 수학식 1-9를 대입해서 하기와 같이 쓴다.Here, the pressure difference measured in Equation 1-4 is the head difference

denoted by

Therefore, Equation 1-9 is substituted into Equation 1-4 and written as follows.

[Equation 1-10]

1.3 Relationship between flow rate and friction coefficient in straight piping

의 관계는 다음 Colebrook-White 식으로 도출할 수 있다.The flow rate Q and the friction coefficient when the friction loss in the pipe acts when the flow is formed in the straight pipe part of the pipe

The relationship of can be derived from the following Colebrook-White equation.

[Equation 1-11]

: 유체 동점성계수이다.Where, e: absolute roughness of pipe,

: is the fluid kinematic viscosity.

2. Non-linear solution using Newton's iterative method

Newton's iterative equation for solving a nonlinear formula system with n unknowns can be written as follows.

[Equation 2-1]

}는 전체 미지수,

의 열벡터, {F}는 전체 공식의 열벡터, 그리고,

은 자코비언행렬, [D]는 역행렬이다. 이때, 자코비언은 수학의 여러 분야에서 적용되고 있으며 하기와 같은 도함수의 행렬로 나타낼 수 있다.here, {

} is the total unknown,

is the column vector of , {F} is the column vector of the overall formula, and

is the Jacobian matrix, and [D] is the inverse matrix. At this time, the Jacobian is applied in various fields of mathematics and can be expressed as a matrix of derivatives as follows.

[Equation 2-2]

}와 {F}를 하기와 같이 나타낼 수 있다. And, similarly {

} and {F} can be expressed as follows.

[Equation 2-3]

,{F}는 선형 공식시스템의 해를 나타내므로 뉴튼법을 사용하여 선형공식 시스템을 반복법으로 풀어 비선형 공식시스템을 해결할 수 있다는 것을 수학식 2-1에서 보여주고 있다.here,

Since , {F} represents the solution of the linear formula system, Equation 2-1 shows that the nonlinear formula system can be solved by solving the linear formula system in an iterative way using Newton's method.

[Equation 2-4]

}에서 수학식 2-4인 선형공식시스템의 해 벡터 {

} 빼면 다음 반복에서의 해 벡터가 된다. 실제로 뉴튼법은 반복법으로 공식시스템을 해결하는 것이다. And, the unknown vector of the current estimate of Equation 2-1 {

}, the solution vector of the linear formula system of Equation 2-4 {

} Subtracting it gives us the solution vector at the next iteration. In practice, Newton's method is an iterative method for solving formal systems.

[Equation 2-5]

}는 [D]{

}={F}를 해결함으로써 구할 수 있는 해 벡터이다. 만일 오직 선형식만이 포함되면 1회 반복으로 엄밀해를 구할 수 있다.In Equation 2-5 above, {

} is [D]{

It is a solution vector that can be obtained by solving }={F}. If only linear equations are included, an exact solution can be obtained in one iteration.

3. Flow Calculation

는 관련 문헌으로부터 구할 수 있다. Pipeline data D and L can usually be obtained from drawings, the absolute roughness e determined by the pipe lining material, and the loss coefficients generated from various devices such as bends, inlets, outlets, and valves.

can be obtained from the relevant literature.

는 문헌에서 구하고,

와

를 측정하면

를 구할 수 있으므로 수학식 1-9와 수학식 1-11로 부터 Q와 f를 제외하고는 모두 기저가 된다. In addition, the kinematic viscosity of the fluid determined by the temperature and pressure measured by installing a thermometer and a pressure gauge at a specific pipe point in the field

is obtained from the literature,

and

If you measure

Since can be obtained, from Equations 1-9 and 1-11, all except Q and f are the basis.

Now, since we have two nonlinear equations 1-9 and 1-11 and two unknowns Q and f, we can solve the unknowns Q and f by Newton's iterative method, and we can solve equations 1-9 and 1-11 It can be derived as follows.

[Equation 3-1]

[Equation 3-2]

에 관해 미분하면 하기와 같다.Here, Equation 3-2 above

If it is differentiated with respect to , it is as follows.

[Equation 3-3]

이다.here,

am.

Then, when Equation 3-2 is differentiated with respect to Q, it is as follows.

[Equation 3-4]

이다.here,

am.

에 관해 편미분하면 하기와 같다.In addition, Equation 3-1 above

The partial derivative with respect to is as follows.

[Equation 3-5]

이다.here,

am.

Then, the partial differentiation of Equation 3-1 with respect to Q is as follows.

[Equation 3-6]

이다.here,

am.

}를 구하고, 이를 수학식 2-5에 대입하여 개선된 해를 구한다. Now, substitute Equations 3-1 and 3-2 into Equation 2-3, and Equations 3-3 to 3-6 into Equation 2-2 according to the procedure described in Equation 3 above. So, from Equation 2-4 {

} is obtained, and an improved solution is obtained by substituting it into Equation 2-5.

와 유량 Q에 대한 해를 구할 수 있다.In this way, if the above procedure is repeated until the error of the improved solution is within the allowable range, the unknown friction coefficient in Equations 1-9 and 1-11

and the solution for the flow rate Q can be obtained.

Hereinafter, the verification results of the official test for the automatic flow calculation device 100 through the measurement of the head loss of the present invention will be described.

- 3rd party verification test by accredited institution

- Test place: K-WATER Research Institute certified calibration institute

- Authorized (testing) institution: Korea Institute of Machinery and Electronic Testing

The official test was conducted by requesting the Korea Institute of Machinery and Electricity Testing, but due to the problem of measuring the large-diameter pipe, the place was inevitably compared and measured using the standard equipment of an internationally accredited calibration institution within the K-water Research Institute.

1. First of all, 7 points of 3.5 bar pressure sensor calibration data were sent and the fitting constant value was exported. Since the temperature sensor also changes by 0.4 to 1.9% per 1 ° C change, 3 points (10 ° C, 20 ° C, 30 ° C) were measured and the correction value was used. .

2. Measurements for each sensor before experiment

go. Temperature sensor: Maintain 15.8℃ (using temperature bath)

me. Level sensor: maintained at 0.35 bar

all. Pressure sensor: After maintaining at 2.879 bar, input pressure offset data

la. Pressure sensor: After entering the offset value, maintain it at 2.862 bar and check the measured flow rate (standard 1360.8㎥/s)

mind. Pressure sensor: Maintain at 2.823 bar and check flow rate (standard 2688.1 ㎥/s)

3. For details of the test, refer to the flow test official test report of FIGS. 6a to 6c.

10: body part 11: fastener
12: connector 13: installation hole
14: waterproof cover
20: pressure sensor unit 30: temperature sensor unit
40: circuit unit 50: display unit
60: communication unit 100: arithmetic device

Claims (5)

In the device installed in the discharge pipe (1) of a hydroelectric power plant and automatically calculating the discharged flow rate,
The body portion 10 and;
A pressure sensor unit 20 connected to the main body 10, installed through the discharge pipe 1, and measuring the pressure of the fluid discharged from the discharge pipe 1;
A temperature sensor unit 30 connected to the main body 10, installed through the discharge pipe 1, and measuring the temperature of the fluid discharged from the discharge pipe 1;
The head loss in the discharge pipe 1 is measured by the pressure value measured by the pressure sensor unit 20 installed inside the main body unit 10, and the measured head loss and temperature sensor unit 30 a circuit unit 40 that collects the temperature values measured in and calculates a flow rate value through a flow calculation algorithm;
A display unit 50 installed on the main body unit 10 and connected to the circuit unit 40 and displaying the pressure value, temperature value, and flow rate value collected in the circuit unit 40; configured to include,
A plurality of connectors 12 are formed on both sides of the body portion 10 to be connected to the pressure sensor unit 20 or the temperature sensor unit 30, and through the connectors 12, the body portion 10 The pressure sensor unit 20 or the temperature sensor unit 30 is connected to the circuit unit 40 provided therein,
The flow calculation algorithm of the circuit part 40 is Equation 1-10 and Colebrook-White equation substituting Equation 1-9 derived from Equation 1-4 and Darcy-Weisbach equation below derived from Bernoulli's theorem. An automatic device for calculating flow rate through head loss measurement, characterized in that the head loss is derived by the derived Equation 1-11.
[Equation 1-4]

[Equation 1-9]

[Equation 1-10]

[Equation 1-11]

(Where, P: pressure of the fluid, r: density of the fluid,

: Various loss coefficients, f: friction coefficient, L: pipe length, D: pipe diameter, V: average flow velocity, g: gravitational acceleration, Q: flow rate, A: cross-sectional area of the pipe

:head loss, e:absolute roughness of pipe,

: Fluid dynamic viscosity coefficient,

: The pressure difference measured in Equation 1-4 is expressed as the head difference.)
According to claim 1,
Automatic flow calculation device through loss head measurement, characterized in that the main body portion (10) is connected to the circuit portion (40) is connected to the communication unit (60) for transmitting and receiving data of the circuit portion (40).
According to claim 1,
A waterproof cover part 14 is further installed on one surface of the body part 10 where the display part 50 is installed to prevent fluid from flowing into the display part 50, and one surface of the waterproof cover part 14 is Automatic flow calculation device through measurement of head loss, characterized in that the display unit 50 is formed transparently to be identified.
According to claim 1,
The flow rate calculation algorithm of the circuit unit 40 automatically calculates flow rate through head loss measurement, characterized in that the flow rate and friction coefficient of Equation 1-10 and Equation 1-11 are derived by the Newton iterative method. delete

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