Predicted water level measurement device

Abstract

To measure a water level in a water extraction pipe by using a sensor which is not in contact with a water surface according to a change of gas pressure in the water extraction pipe.SOLUTION: In a known water taking-out device, a water taking-out device is arranged at a position lower than a city gas supply pipe buried underground, a water extraction pipe extending vertically from the bottom of the water taking-out device to a manhole on the ground is provided, a lower end of the water extraction pipe is opened, and an upper end of the water extraction pipe is sealed with an openable / closable sealing body. In the water taking-out device, a gas pressure sensor for measuring a gas pressure in the water extraction pipe is provided on an upper part of the water extraction pipe, and a water level in the water taking-out device is predicted and converted by a change of the gas pressure sensor.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a predictive water level measuring device for a water collector that is set up to prevent water from entering a gas pipe through which city gas flows and causing a disruption to the supply of gas. [Background technology]

[0002] In the past, when water seeped into holes or gaps that appeared due to corrosion or other factors in city gas supply pipes buried underground, the water gradually accumulated inside the gas pipes, causing the pipes to become clogged and city gas to stop flowing, which could cause an interruption to the city gas supply. In order to prevent the above-mentioned problems from occurring, conventionally, a water collector (such as a water collection device) is placed at a lower position than the supply piping, and when water accumulates in the water collector, water is pumped up from a thin extraction pipe that extends vertically from the bottom of the water collector to a handhole at ground level, and the amount of water accumulated in the water collector is measured. When water accumulates in the water collector, water is pumped up again using a pump or other device and the amount of water accumulated in the pipe is measured. Also, regular checks are made until the water in the water collector runs out and city gas is discharged from the top of the extraction pipe (see Figure 1). However, the task of periodically checking whether or not there is accumulated water in all of the water collectors installed under general roads is cumbersome and places a heavy workload on the workers. In addition, if water accumulates, it must be extracted before the capacity of the water extractor is exceeded. However, because it is currently unknown how much water will accumulate or how quickly it will accumulate, it is necessary to visit the site frequently and check by extracting the water from the ground each time. It is possible to predict the rate at which water will seep in by recording the amount of water extracted and the changes in the extraction intervals when extracting water on-site, but this work must be repeated over a long period of time. One possible method to address this issue would be to insert a water level sensor from the top of the water extractor to measure the level of water accumulated inside and measure the level of water accumulated in the extraction pipe. However, this would require a series of steps, such as inserting the sensor into the top of a thin extraction pipe that extends to ground level using a small handhole while suppressing the escape of city gas, and then suspending the sensor by wire to the bottom of the water extractor, which is at a different height for each site, and then blocking the top, which is undesirable in terms of workability and safety. In addition, if the inside diameter of the water extraction pipe is small, a commercially available water level sensor cannot be inserted in. Furthermore, the water level in the water extraction pipe does not match the water level of the water accumulated in the water extractor.

[0003] Therefore, in the water remover of Patent Document 1, JP 2021-188666 A, a water remover is proposed which includes a receiving portion fused to surround the outer periphery of a water drain hole drilled in the lower wall of a gas pipe in which a gas flow path is arranged horizontally, a cylindrical water inlet portion formed continuously with the receiving portion, connected to the water drain hole, and protruding downward, a water storage tube connected to the water inlet portion and for storing water, and a water drain pipe connected to the water storage tube and extending upward outside the water storage tube. In the above-mentioned configuration, a drain hole is provided in the lower wall of the gas pipe, and a drain pipe is provided which is connected to the water storage pipe and extends upward outside the water storage pipe. Therefore, the task of periodically checking whether or not there is accumulated water in all the installed water collectors is a heavy workload. In addition, if water accumulates, it must be extracted before the capacity of the water extractor is exceeded, but because the current situation does not allow for the amount of water accumulating or the rate at which it will accumulate, it is necessary to visit the site frequently and perform water extraction work from above ground each time to check. Furthermore, when water is extracted on site, the amount of water extracted and the changes in the extraction intervals are recorded to predict the rate at which the water will enter, so this work must be repeated over a long period of time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-188666 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, a method can be considered in which a gas pressure sensor is provided at the head side of the extraction pipe, which is installed vertically or longitudinally from the bottom of the water collector at a depth of several meters from the ground, to measure the gas pressure inside the extraction pipe, which is compressed depending on the height of the water accumulated in the extraction pipe, and the gas pressure is converted into an electrical signal, output, and the water level in the extraction pipe is measured. That is, a sensor is inserted into a thin water extraction pipe in a small manhole while suppressing the escape of city gas, and the water level in the water extraction pipe can be measured based on the change in gas pressure. Effect of the Invention

[0006] In this invention, a removable sealing body is provided to seal the upper end of the water extraction pipe, a gas pressure sensor is installed inside, and the water level is calculated using a method for predicting the water level in the water extraction pipe and the water extractor from the internal pressure of the sealed gas in the water extraction pipe, thereby making it possible to measure the water level accumulated in the water extraction pipe or the water extractor and predict and determine the time to extract water. [Brief description of the drawings]

[0007] [Figure 1] FIG. [Diagram 2] FIG. 2 is a perspective view showing an example of a cap provided at an upper end of a water extraction pipe. [Diagram 3] FIG. 4 is an explanatory diagram showing an example of a gas pressure sensor provided in a cap. [Figure 4] FIG. 1 is an explanatory diagram showing a state in which no water has accumulated in the water extractor and the lower end of the water extraction pipe is not blocked. [Diagram 5] FIG. 1 is an explanatory diagram of a state in which water has begun to accumulate in the water extractor and the lower end of the water extraction pipe is completely blocked. [Figure 6] FIG. 6 is an explanatory diagram of a state in which water has further accumulated from the state shown in FIG. 5 and has infiltrated up to an arbitrary position in the water extraction pipe. [Figure 7] FIG. 1 is a schematic diagram of a capacitive level sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0008] In this embodiment, a water collector 2 connected to a part of a city gas supply pipe 1 is installed at a lower point than the city gas supply pipe 1 buried underground, and water that has entered the pipe 1 can be collected in the water collector 2 (Figure 1). The water collector 2 is inserted vertically into a manhole (hand hole) 4 with a lid 3 on the ground, with the lower end located near the bottom of the water collector 2, and a water extraction pipe 5 is installed with the upper end located at the top of the manhole 4. The extraction tube 5 is a hollow tube whose lower end is open and whose upper end is sealed by a plug 6.

[0009] This embodiment is characterized in that the pressure inside the water extraction pipe 5 is measured by a pressure sensor S, and the water level of the accumulated water in the water extraction pipe 5 is predicted and calculated based on the internal pressure of the water trapped in the water extraction pipe 5.

[0010] In the illustrated example, the bottom surface of the water extractor 2 is substantially flat, and it is preferable that the surface facing the bottom surface of the water extraction pipe 5 is substantially parallel to it. As shown in FIG. 4, when there is no water in the water extractor 2, the gas in the piping 1 passes through the water extractor 2 and into the water extraction pipe 5, and the pressure P0 in the water extraction pipe 5 is approximately the same as the pressure of the city gas. Therefore, the pressure sensor S senses a pressure that is approximately the same as the pressure of city gas, and upon detecting this pressure, the sensor S determines that the water level in the water extraction pipe 5 is 0 mm. This is also true when water has accumulated in the water collector 2 but the water has not accumulated up to the position H1 where the bottom of the water extraction pipe 5 is not blocked by the surface of the water accumulated in the water collector 2 and is sealed.

[0011] Next, FIG. 5 illustrates a case where water gradually accumulates at the bottom of the water extractor 2, and the water accumulates up to a position H1 (for example, 1 to 2 cm) where the bottom of the water extraction pipe 5 is blocked by the surface of the water accumulated in the water extractor 2 and the inside of the water extraction pipe 5 is sealed. The upper end of the water extraction pipe 5 is removably sealed with a lid or plug such as a plug 6. Therefore, when water accumulates beyond the position H1, city gas does not flow through the water extraction pipe 5, and the pipe becomes sealed. The gas pressure in the water extraction pipe 5 becomes the predetermined pressure P1, and the extraction pipe water level is determined to be +0 mm.

[0012] Next, when the water accumulates inside the water extractor 2 and exceeds the bottom of the water extraction pipe 5, and further water passes through the water extractor 2 and enters the water extractor 2, accumulating up to H2, the water in the water extraction pipe 5 also rises to h2, and the gas pressure in the water extraction pipe 5 rises to P2. Therefore, the water level in the water extraction pipe 5 is measured based on the pressure P2. In this way, the gas pressures P0 to P2 in the water extraction pipe 5 can be measured in advance by experimentally determining in advance the cross section and length of the water extraction pipe 5, and thereby the water level can be measured from the gas pressure in the water extraction pipe 5. The water collector 2 is not limited to those of the same shape and capacity, and measurement is possible. Furthermore, since the water level h2 of the accumulated water in the water extractor 2 is correlated with the water level H2 of the water extraction pipe 5, it is possible to calculate not only the water level in the water extraction pipe 5 but also the water level in the water extractor 2 by simply measuring the pressure in the water extraction pipe 5.

[0013] In this embodiment, a removable plug 6 is used as the sealing body 6 provided at the upper end of the extraction tube 5 in FIG. 2, and it is preferable to install a gas pressure sensor S at a position where the pressure inside the sealed tube can be measured. In this embodiment, a small gas pressure sensor is installed near the plug 6 at the top of the extraction pipe 5 in the manhole (hand hole) 4, thereby making it possible to measure the water level in the extraction pipe 5. However, the attachment position of the sensor S may be anywhere in the extraction pipe 5 as long as it is a location where the gas pressure inside the extraction pipe 5 can be measured, and it is not necessary to be limited to the embodiment. FIG. 3 shows a different embodiment of the enclosure 6 and the gas pressure sensor S. The gas pressure sensor may be any sensor that is integral with the well-known sealed body 6 and can measure the pressure of the compressed gas in the extraction pipe 5.

[0014] In the present invention, the gas pressure sensor S is used, so the water level is detected by gas pressure without contacting the water accumulated in the water extraction pipe 5, so detection is not time-consuming and measurement is possible even if the water extractor 2 is a thin tube. In addition, the water level in the water extractors and extraction pipes installed at multiple locations in the city gas supply pipes can also be estimated by measuring the gas pressure in any one of the extraction pipes. Moreover, since the measurement results are converted into electrical signals, the measurement results can also be transmitted to an administrator. Furthermore, by connecting the detection results of the gas pressure sensor with the detection results of the gas pressure sensors of different extraction pipes provided in the same supply pipe, it is possible to monitor water leaks in the entire supply pipe. In addition, it is possible to reduce the workload for checking the water extraction, improve safety by reducing the amount of city gas emitted during installation and removal, improve the ease of installation in narrow manholes (handholes), and reduce the cost of manufacturing the equipment. Furthermore, by using a capacitance type level sensor S2 (see FIG. 7) in addition to the gas pressure sensor S, accuracy can be improved. [Explanation of symbols]

[0015] 1 City gas supply piping 2 water collector 3 Lid 4 Hand holes 5 Water extraction pipe 6 Plug S Gas Pressure Sensor

Claims

1. A water collector is disposed at a position lower than the city gas supply pipe buried underground, and a water extraction pipe is provided extending vertically from the bottom of the water collector to a manhole on the ground; The lower end of the water extraction pipe is open, and the upper end is sealed with an openable and closable sealing body, A gas pressure sensor for measuring the gas pressure in the water extraction pipe is provided on the upper part of the water extraction pipe, and the water level in the water extraction pipe is predicted and converted into a transition based on the change in the gas pressure sensor.

2. 2. The device for measuring a predicted water level of a water extractor according to claim 1, wherein the gas pressure sensor is built into a sealed body at the top of the water extraction pipe.

3. 3. The predictive water level measuring device according to claim 1, wherein the accuracy can be improved by using a capacitance type level sensor in combination with the gas pressure sensor.

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