JPH0552663A - Measuring method for lengthwise mean water temperature in water distributing pipe - Google Patents

Abstract

PURPOSE:To measure a mean water temperature in a pipe easily by providing an electric resistance wire along the lengthwise direction of a water distributing pipe, filling water in the pipe, and measuring the electric resistance of the electric resistance wire. CONSTITUTION:Electric resistance wires 12, 13 made of iron wire, copper wire, or the like are provided along the directions of respective riser portions 2, 3, in a communicating water pipe 1 buried in the ground G. And resistance measuring instruments 14, 15 are respectively connected between upper and lower end portions 12b, 12a, and between upper and lower portions 13b, 13a of the riser portions 2, 3, via lead wires 14b, 14a and lead wires 15b, 15a. When water is poured into the pipe 1, respective water heads 4, 5 are exhibited at the riser portions 2, 3, and the wires passing through the water heads 4, 5 are applied for level measurement. When the water temperature of the riser portion 3 is higher than the water temperature of the riser portion 2, the water head 5 rises. Then, the electric resistance value changes of both terminals of the resistance wires 12, 13 are read out by means of the measuring instruments 14, 15, and the water temperatures of the riser portion 2, 3 are obtained from the changes, and the value of the water head 5 is corrected thereby so as to obtain the real water head 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for measuring the level of vertical displacement due to a phenomenon such as subsidence or upheaval of the ground and a structure built therein, by means of a communicating water pipe, or in water pipes in cold regions. The present invention relates to a method for measuring an average water temperature in the length direction in a water distribution pipe used when measuring the temperature of water that is stationary inside the pipe, such as a pipe of melted ice water.

[0002]

2. Description of the Related Art Conventionally, when measuring the level of the ground using the above-mentioned communication water pipe, one end of the communication water pipe is arranged at a reference point of the ground and the other end is arranged at a measurement point of the ground. , When the temperature of the water in the communication water pipe is uniform over the entire length thereof, assuming that the water heads at both ends are in the same horizontal plane, the water head at the other end of the communication water pipe is The level up to the measurement point is used as the level between the reference point and the measurement point.

However, since the communication water pipe is buried in the ground, if there is a temperature difference between the parts of the ground, the water temperature in the communication water pipe also partially differs in the length direction. ..

Therefore, if there is a difference in the water temperature between the rising portion at one end and the rising portion at the other end of the communicating water pipe, there will also be a difference in the water density at those portions, and the water head at the measurement point will be different. It will not be located in the horizontal plane including the head of the reference point.

Therefore, in order to obtain the water head at the measurement point when the water temperature is uniform over the entire length of the communication water pipe, it is necessary to measure the water temperature of each part in the communication water pipe and correct the water head based on that. I won't.

However, since the water temperature of each portion is measured in the lengthwise direction of the communicating water pipe, it is practically difficult to install a thermometer finely over the entire length of the communicating water pipe, and the communicating water pipe is buried deep in the ground. If so, this difficulty is particularly pronounced.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a large number of temperatures along the length direction when there are differences in water temperature in each part within a predetermined section such as a rising part in a communicating water pipe. It is to obtain a method that can easily measure the average water temperature of each part in the length direction without installing a meter.

Another object is to obtain a suitable water pipe for carrying out the above measuring method.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides an electric resistance wire such as a metal wire along the length direction of a water pipe buried in the ground, and the electric resistance in a state where the water pipe is filled with water. This is a method of measuring the average water temperature in the length direction of a predetermined section in the water distribution pipe by measuring the electric resistance of the line in the length direction corresponding to the temperature at that time. Also,
An electric resistance wire such as a steel wire or an alloy wire is embedded in a coil in the thickness of a flexible water distribution pipe made of rubber or soft synthetic resin, and connection terminals are formed at both ends of a predetermined section of the electric resistance wire. This is a flexible pipe for measuring the temperature in the water distribution pipe.

[0010]

Embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, an electric resistance wire 12 made of a metal wire of iron, copper, nickel, chromium or the like is provided in a communication water pipe 1 buried in the ground G along the length direction of each rising portion 2, 3. 1
3 is provided between the upper and lower end portions 12a and 12b of the one rising portion 2 of the electric resistance wires 12 and 13 and between the upper and lower end portions 13a and 13b of the other rising portion 3 respectively. Lead wires 14a and 14b and lead wire 1
Connect at 5a and 15b.

When water is put into the communicating water pipe 1 in this state,
The water in the communication water pipe 1 shows a head 4 and a water head 5 at one rising part 2 and the other rising part 3 of the communication pipe, respectively, and is stable, and the line passing through the water head 4 and the water head 5 is horizontal, so that the level is high. It is applied to measurement. The purpose can also be achieved by measuring the water pressure p of the rising portions 2 and 3 at the both ends.

Generally, the relationship between the head height h and the water pressure p is p = γw · h h = p / γw where γw is the specific gravity of water.

Since the specific gravity of water changes depending on the water temperature, when the water heads 4 and 5 at both ends have a temperature difference between the two rising portions 2 and 3, for example, the water temperature of the rising portion 3 is higher than that of one rising portion 2. If it is high, the water head 5 rises and the water head 5
Since the position is a, the true level cannot be measured.

When measuring the water temperature of one rising portion 2 and the water temperature of the other rising portion 3, both terminals 12a, 12b and 13 of the electric resistance wires 12 and 13 of both rising portions are measured.
The electric resistance values of a and 13b are read by the resistance measuring devices 14 and 15, and the value of the water head 5a is corrected thereby, and the true water head 5 is obtained.

As shown in FIG. 1, an extension portion 1a of the communication water pipe 1
When the pipe is horizontally piped, the water pressures p and p at both ends represent the level regardless of the water temperature.
When there is a step on the surface, the change in specific gravity due to the water temperature difference cannot be ignored.

FIG. 2 shows a configuration in which the level is measured by water pressure measurement under a piping condition in which the step portion 11 is provided in the extension portion 1b. When the level is measured by water pressure, a communicating water pipe connected to the pressurized water is provided at the measurement point 10, and the reference point water pressure at the rising point 9 of the pressurized water is p1 and the water pressure at the measurement point 10 is p2. Water pressure p1, p2 acting on each point 9, 10
Is the rise of the pressurized water 8 h1, the step of the extension 1b is h
2. If the specific gravity of water in the rising part 2 of the pressurized water 8 and the step part 11 is γw1 and γw2, then p1 = γw1 · h1 p2 = p1 + γw2 · h2, and the water pressure p1 at the reference point 9 also acts on the measuring point 10. Therefore, the fluctuation of h1 can be measured by subtracting the water pressure p1 at the reference point 9 from the water pressure p2 at the measurement point.

The specific gravity of water is 1 × 10 −4 to ^{4 at} room temperature.
× It is necessary to correct the temperature measurements from the stepped portion height h1 is greater becomes large error because changes by about 10- ^4.

According to the present invention, the electric resistance wire 12 is provided inside the communication water pipe 1 or in the coating layer on the outer peripheral surface of the communication water pipe 1, and the electric resistance wires 12 and 13 are changed by the change in the water temperature in the water distribution pipe 1. The change in water temperature is detected and the water temperature is calculated from the change.

At this time, the electric resistance wires 12 and 13 can be put in any section of the communicating water pipe which requires measurement, and the electric resistance of the electric resistance wires 12 and 13 changes according to the water temperature of each part,
The electrical resistance of the resistance wire 12 between the terminals 12a, 12b of the measurement lead wires 14a, 14b, 15a, 15b represents the average resistance value of the entire length of the resistance wire 12 in the measurement section, that is, the average temperature of the measurement section. .. Electric resistance wire 12, 13
As the wire, an iron wire, a copper wire, a platinum wire, or the like can be used. As shown in FIGS. 1 and 3, when the covered wire of the resistance wire 12 is directly put in the water in the communicating water pipe 1, and when the wire is shown in FIGS. There is a case where it is embedded in the coating of the communication water pipe 1 as shown in. Since the density of water in the communicating water pipe of the present invention is proportional to the water temperature as described above, this error can be corrected by measuring the water temperature of the rising water pipe.

The following figure shows an embodiment of the present invention. A special thermometer is set at a rising height of about 1.9 m in FIGS. 6 and 7, the average water temperature at the rising portion is obtained, and the level is corrected from the measurement result. Here is an example: In addition, the level correction by measuring the water temperature is effective when the rising part of the water pipe has a constant slope (including vertical), and the influence degree of the water temperature is uncertain when there is undulation in the entire pipe. It is not practical.

[0021]

Since the present invention is as described above, it is not necessary to define the number of temperature measurement points required to obtain the average water temperature in the length direction, and the temperature at all points in the measurement section can be measured. Then, the same effect as in the case of obtaining the average temperature can be achieved with one thermometer. As a result, it is possible to improve the correction accuracy when correcting the level based on the measured temperature in the water pipe, and the economical efficiency at that time.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view of another embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view taken along line III-III in FIG.

FIG. 4 is an enlarged vertical sectional view of a part of FIG.

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a diagram after correction of an experimental example of the present invention.

FIG. 7 is a diagram before correction of an experimental example of the present invention.

[Explanation of symbols]

 1 Communication water pipe 2 Water pipe rising part 3 Water pipe rising part 12 Electric resistance wire 12a Upper end part 12b Lower end part 13 Electric resistance wire 13a Upper end part 13b Lower end part 14 Resistance measuring instrument 15 Resistance measuring instrument

Claims (7)

[Claims] 1. An electric resistance wire is provided along the length direction of the water distribution pipe, and the electric resistance in the length direction of the electric resistance line is measured in a state where the water distribution pipe is filled with water. A method for measuring the average water temperature in the lengthwise direction of a water distribution pipe. 2. The method for measuring the average water temperature in the longitudinal direction of the water pipe according to claim 1, wherein the water pipe is embedded in the ground whose level is measured by subsidence and uplift. 3. The average in the length direction in the water pipe according to claim 1, wherein the electric resistance wire provided along the length direction of the water pipe is arranged inside the water pipe. How to measure water temperature. 4. The length direction in the water pipe according to claim 1, wherein an electric resistance wire provided along the length direction of the water pipe is arranged in contact with the outside of the water pipe. How to measure average water temperature. 5. The lengthwise direction in the water pipe according to claim 1, wherein the electric resistance wire provided along the lengthwise direction of the water pipe is embedded in the wall thickness of the water pipe. Method for measuring the average water temperature of water. 6. The water distribution pipe according to claim 1, wherein the electric resistance wire provided along the length direction of the water distribution pipe is formed in a spiral shape on the circumference of the water distribution pipe. A method for measuring the average water temperature in the length direction. 7. A pipe characterized in that an electric resistance wire is embedded in a winding shape along the length direction in the thickness of a flexible water distribution pipe, and a connection terminal is formed on the electric resistance wire. Flexible tube for measuring internal temperature.