JPS60259912A - Flow measurement in branch pipe - Google Patents

Abstract

PURPOSE:To reduce measuring costs, by measuring only a flow of a branch pipe, introducing this measured flow into a function generating means as an input and using an output signal of this function generating means as a totalled flow of each individual branch pipe. CONSTITUTION:At the time of actual measurements, transmitting and receiving instruments 31, 32 related to one side branch pipe 2A and the No.1 supersonic wave flowmeter proper 5 are used and after obtaining a measured flow signal Q1 corresponding to the measured flow of the one side branch pipe 2A as the output of the aforesaid supersonic wave flowmeter proper 5, the signal Q1 is applied to the function generating means 7 as an input and the output signal from this means is adopted as the total sum of flows of the branch pipes 2A, 2B. Here, the moment when the relation between Q1 and total flow Q1+Q2 are determined is that when the branch pipes 2A, 2B are installed or inspected and transmitting and receiving instruments 41, 42 relative to the other side branch pipe 2B and the No.2 supersonic wave flowmeter proper 6 may only be installed when the same are installed and inspected. Consequently, costs for measurements can be low and economically profitable measurements are available.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a branch pipe that branches into a plurality of pipes from a main water pipe, each of which flows at a flow rate that has a fixed relationship with the flow rate of the main water pipe, such as a water pipe. This invention relates to a method for measuring the flow rate of a branch pipe such as an aqueduct bridge that branches from a main pipe and crosses a river.

BACKGROUND ART In general, water is sometimes conveyed using a plurality of branch pipes branching from a main water supply pipe. For example, when transporting water across a river, if the water main pipe has a large diameter, 1.
As shown in Figures 3 and 4, from the water main pipe 1 to 2, for example.
Branched into the main flow pipe 2A.

2B is passed between the rivers by piers 21 and 22. In this way, two people serve as a water pipe bridge.

The reason for using 2B is that the large-diameter water main pipe 1 has a large weight when it is full, so by branching it into two pipes, the unit weight can be reduced.

By the way, when measuring the flow rate in the above-mentioned facilities, a conventional method is used.

■ A method of measuring the flow rate of underground water mains with a large-diameter flow meter.

■Measure the flow rate of the branch pipes 2A and 2B on the bridge with two small-diameter flowmeters, and add the outputs.

■ Attach an ultrasonic flowmeter transmitter/receiver to one of the branch pipes 2A and 2B on the bridge, and use the two-line method (a method in which the submerged ultrasonic wave paths viewed from the pipe axis direction are orthogonal to each other) to measure two diameters. A method of calculating the average flow velocity and converting it into double.

However, methods ■ and ■ can perform highly accurate measurements, but method ■ requires the construction of underground bits and equipment such as drainage pumps, resulting in high construction costs. This is economically disadvantageous because the counter and adder must be operated all the time. On the other hand, method (2) is inexpensive, but requires that the quality, thickness, and diameter of the diverter pipes be exactly the same, and if there is a difference in flow rate, the difference will be insensitive to changes in flow rate. Since the flow rate varies linearly, it is necessary that the flow rates are approximately the same, and the applicable range is narrow. And in the actual construction, 1 branch pipe 2A.

2B is often not symmetrical with respect to the water main pipe 1, and in this case, there will be a difference in flow rate between the two pipes, making it impossible to perform highly accurate measurements using method (2).

Problems to be Solved by the Invention The present invention has been made under these circumstances, and is capable of consistently performing highly accurate measurements, is economically advantageous, and has a wide range of applicability. The purpose of this invention is to provide a method for measuring the flow rate of a wide branch pipe.

Means for Solving the Problems The present invention changes the flow rate of the water pipe in advance at the time of installation or inspection of the branch pipe, and uses, for example, an ultrasonic flow meter to measure the flow rate of each branch pipe for each flow rate. By measuring the relationship between the measured flow rate of the - branch pipe and the total flow rate of the measured flow rate of each branch pipe, for example, by programming this relationship into the function generating means, the input/output characteristics of the above relationship can be obtained. When the function generation means is set and used in actual use, that is, when actual measurement is performed, the flow rate of only the above-mentioned - branch pipe is measured, this measured flow rate is input to the function generation means, and the flow rate of this function generation means is This is a method in which the output signal is used as the total flow rate of each flow rate of the branch pipes.

Example The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a block diagram showing an example of an apparatus for carrying out the method of the present invention, and in this embodiment, an ultrasonic flowmeter is used to measure the flow rate. A pair of transceivers 31, 32 and 41, 42, which are ultrasonic sensors, are installed in the branch pipes 2A and 2Bl'i, which are branched into two from the main water supply pipe 1. The pair of transmitters/receivers 41 and 42 are connected to the first ultrasonic flowmeter body 5, and the other pair of transmitters/receivers 41 and 42 are connected to the second ultrasonic flowmeter body 6, respectively.

In the measurement method according to the embodiment of the present invention, first, the flow rate of the water main pipe 1 is changed experimentally in advance, and the flow rates of both the branch pipes 2A and 2B are measured for each flow rate, and the flow rate of one of the branch pipes 2A is measured. The relationship between the measured flow rate and the total flow rate of the measured flow rates of both branch pipes 2A and 2B is determined. The measured flow rates of the flow dividers 2A and 2B are the output signals Q+ and Q of the ultrasonic flowmeter bodies 5 and 6, respectively.
Since it corresponds to t, the above relationship becomes a relationship between Ql and Q, +Q2. After determining the relationship between Q and Ql'';h, the function generating means 7
Set. The setting of the function generating means 7 is, for example, θ of Ql.
This is done by programming the above relationship for ~100 units. FIG. 2 is a graph showing an example of the input/output characteristics of the function generating means 7, and the dashed line (1) indicates the Q
Characteristics when I<Q2, real #(II));t Q,=Q
, ノ8 Combined % sex, 2A dashed line (il+1 haC
The characteristics when L and >Qv are shown. The magnitudes of Q1 and Q2 are determined by the diameters of the branch pipes 2A and 2B, the suspended solids, or the state of the construction. Next, during actual measurement, one of the branch pipes 2A
Using the transceivers 31 and 32 and the first ultrasonic flowmeter body 5 related to vC, the measured flow rate signal Q corresponding to the measured flow rate of two -10,000 branch pipes is outputted from the ultrasonic flowmeter body 5. This measured flow rate signal Q is inputted to the function generating means 7, and the output signal from the function generating means 7 is sent to the branch pipe 2. A,
Adopted as the total flow rate of 2B flow rate.

Here, we experimentally changed the flow rate of water main pipe 1 to Q and Q.
Specifically, the time to determine the relationship between r+Qx is, for example, at the time of installation or inspection of the diverter pipe 2BK, and the transmitter/receiver 41, 42 and the second ultrasonic flowmeter related to the other diverter pipe 2BK. The main body 6 only needs to be attached during the above-mentioned installation or inspection.

Furthermore, in the present invention, the measurement of flow rate is not limited to using an ultrasonic flowmeter.

Effects of the Invention As described above, according to the present invention, the relationship between the measured flow rate of the branch pipe (-) and the measured flow rate of the entire branch pipe is determined in advance, and during actual measurement, the relationship is determined based on this relationship and the measured flow rate of the branch pipe (-). Since the pseudo total flow rate is obtained using the function generation means,
At the time of actual measurement, it is necessary to measure only the flow rate of the - branch pipe, so the cost of measurement is low and it is economically advantageous. Moreover, since the above relationship is determined by the state of construction of the diverter pipe, the material of the diverter pipe, etc., by calculating the total flow rate based on this relationship in advance, it is possible to Highly accurate measurements can be made regardless of the situation, and therefore the range of application is wide.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an example of an apparatus used in the method of the present invention;
FIG. 2 is a graph showing an example of the input/output characteristics of the function generating means, and FIGS. 3 and 4 are a side view and a plan view, respectively, showing the construction state of the diverter pipe. 1... Water supply main pipe, 2A, 2B... Branch pipe, 31,
32. 41, 42 - Transmitter/receiver, 5.6... Ultrasonic flowmeter main body, 7... Function generating means.

Claims (1)

[Claims] In the method of measuring the flow rate of multiple branch pipes branched from the water main pipe, the flow rate of the water pipe is changed in advance, and the flow rate of each branch pipe is measured for each flow rate, and the measured flow rate of the - branch pipe and each branch pipe are calculated. The relationship between the measured flow rate of the diverter pipes and the total flow rate is determined, and the function generating means is set to obtain input/output characteristics corresponding to this relationship. During actual measurement, the flow rate of only the above-mentioned diverter pipes is measured. A method for measuring a flow rate in a diverter tube, characterized in that the measured flow rate is input to the function generating means, and the output signal of the function generating means is used as the total flow rate of each flow rate in the diverter tube.