JP6742018B2 - Unknown water estimation method - Google Patents

Description

The present invention relates to an unknown water estimating method for estimating the flow rate of unknown water flowing into a sewer pipe connected to a manhole provided with a manhole pump.

In the split sewer system, rainwater and wastewater are not treated by the same confluence pipe, but a rainwater drainage pipe that discharges rainwater to a river and a wastewater drainage pipe that treats wastewater are constructed to treat rainwater and wastewater separately. There is. Therefore, since the sewer pipe system is basically designed to treat only wastewater, for example, rainwater may flow into the sewer pipe due to damaged sewer pipes, or cracks may occur in the sewer pipe. When the wastewater flows into the wastewater pipe, the flow rate inside the wastewater pipe increases, increasing the load on the sewage treatment plant, and in some cases, sewage that exceeds the treatment capacity flows into the sewage treatment plant and the treatment plant malfunctions. Can also occur.

Therefore, it is necessary to confirm whether there is inflow of unknown water such as rainwater or groundwater, and if there is an inflow, identify the inflow location and make necessary repairs. Is performed by installing a flow meter as described in Patent Document 1 in an invert of a manhole.

Registered utility model No. 3061715

When the flume type flow meter as described in Patent Document 1 is used, the flow rate is calculated by measuring the water level with an ultrasonic water level sensor, but the flume type flow meter is expensive and the flow rate measurement point It is difficult to manage the equipment because it is necessary to have a large amount of flumes of the size that matches the pipe diameter of Therefore, when it is necessary to conduct flow rate surveys at a large number of survey points, such as unknown water surveys, the flow rate survey is carried out while a small number of flow meters are installed in sequence at the survey points, which increases the survey period.

Therefore, an object of the present invention is to provide an unknown water estimation method capable of estimating the amount of unknown water flowing into a sewer pipe using a simple device.

The unknown water estimation method of the present invention for achieving this object is an unknown water estimation method for estimating the amount of unknown water flowing into a sewer pipe, and is a manhole of a pump facility provided in the sewer pipe. Detecting the drive current supplied to the manhole pump provided in the, and recording by specifying the operating time zone of the manhole pump based on the detected drive current, based on the recorded operating time zone of the predetermined time zone The sewage flow rate flowing into the manhole is determined, and the unknown water amount is estimated based on the determined sewage flow rate. The manhole pump operates by supplying the driving current. Between the operating hours of the manhole pump, that is, while the manhole pump is stopped, sewage corresponding to one pump-up water amount flows into the manhole. Therefore, it is possible to calculate the sewage amount during the stop time by dividing the pump-up water amount for one time by the stop time of the manhole pump, and it is possible to determine the unknown water amount from the calculated sewage amount. That is, the sewage flow rate can be determined based on the time between operating hours of the manhole pump and the amount of water pumped up by the manhole pump once.

The drive current supplied to the manhole pump can be detected by connecting the clamp type AC current sensor to the cable or cord for supplying the drive current to the manhole pump in the control panel installed in the pump facility. it can. The clamp type AC current sensor detects a current by, for example, picking up a magnetic field generated around a driving power supply at a clamp portion.

The unknown water estimation method of the present invention can be carried out by using an AC current sensor or a clamp ammeter based on a driving current of a manhole pump.

It is a figure explaining a processing procedure from investigation grasp of unknown water to measures. It is a figure which shows a pump facility. It is a figure which shows the state which attached the clamp type alternating current sensor to the cable of the control apparatus. It is a graph which shows the detection result of the clamp type alternating current sensor on a sunny day. It is a graph which shows the detection result of the clamp type alternating current sensor of another fine day. It is a graph which shows the detection result of the clamp type alternating current sensor on a rainy day.

First, with reference to FIG. 1, a processing procedure from investigation and grasp of unknown water such as rainwater infiltration water or constant infiltration water (groundwater, seawater, etc.) to countermeasures will be described.

In the investigation of unknown water, first, the history of maintenance and management of the sewer pipe in the past is investigated (preliminary investigation), and a survey area (specific large block) of several hundred hectares is selected (S1). Next, the sewage flow rate in rainy or sunny weather is measured to investigate the unknown water volume, and the middle block of about 20 to 30 hectares to be surveyed is narrowed down (S2), and the sewage flow rate in rainy or clear weather is measured. The amount of unknown water is investigated by narrowing down small blocks of about 2 to 5 hectares as a model area (S3), but the survey of unknown water amount performed in S2 may be a rough one, as shown in FIG. It is possible to use such a clamp type AC current sensor that detects the time period of supplying the drive current to the manhole pump. Then, after narrowing down the small blocks, a damaged portion or the like is confirmed using a TV camera car or the like running in the sewer pipe, and a repair priority is calculated based on the degree of the damaged portion or the like to calculate the repaired portion (S4). When the repaired part is calculated, repair work is carried out (S5), and the investigation of the unknown water amount is carried out again at the same part as S3 to confirm the improvement effect (S6). These survey results and improvement effects are stored as sewer maintenance data (S7) and are used, for example, to calculate repair points in a sewer pipe in the same situation (S8).

Next, with reference to FIG. 2, the configuration of the pump facility used for implementing the unknown water estimation method according to the present invention will be described.

The pump facility 1 is, as an underground structure, a manhole 5 that stores the sewage A that flows in from the sewage pipe 3, and a 2 provided in the manhole 5 for discharging the stored sewage A to the discharge pipe 7. The base manhole pump 9, a pumping pipe 11 for pumping the sewage A discharged to the discharge pipe 7, a water level rise detection sensor 13 for detecting the rise of the water level of the sewage A and starting the operation of the manhole pump 9, and a sewage A water level lowering detection sensor 15 for detecting the lowering of the water level of A and stopping the operation of the manhole pump 9, and receiving detection signals from the water level rising detection sensor 13 and the water level lowering detection sensor 15 as a ground installation. A control device 17 (control panel) for supplying power to the manhole pump 9 and stopping power supply to the manhole pump 9 is provided. A cable 19 having an electric power line is connected between the control device 17 and each manhole pump 9.

A method of detecting the operating state of the manhole pump 9 will be described with reference to FIG.

In the unknown water estimation method, first, the operating state of the manhole pump 9 is detected. The operation state of the manhole pump 9 is performed by attaching a clamp type AC current sensor 21 to the cable 19 and detecting the driving AC current flowing when the manhole pump 9 is operating. The clamp type alternating current sensor 21 is attached to each cable 19, and each clamp type alternating current sensor 21 is connected to the data processing device 23. In the data processing device 23, the AC current value detected by each clamp type AC current sensor 21 is displayed on the display 25 and recorded together with the detection time information. It should be noted that at the time of one pump up (while the water level of the sewage A falls from the water level rise detection sensor 13 position to the water level fall detection sensor 15 position), the pair of manhole pumps 9 alternately repeat the operation.

FIG. 4 is a graph showing an example of the detection result of the clamp type AC current sensor 21 on a sunny day, FIG. 4 is a graph showing an example of the detection result of the clamp type AC current sensor 21 on another sunny day, and a clamp type AC in the rain. A method of estimating the unknown water amount from the recording result of the data processing device 23 will be described with reference to FIG. 6, which is a graph showing an example of the detection result of the current sensor 21. 4 to 6, it means that the sewage corresponding to the pump-up amount once flows into the manhole 5 during the time during which the drive current value is detected.

In FIG. 4, the manhole pump 9 is not operating from midnight to 6 am. Since it is considered that there is still considerable domestic wastewater around midnight, the sewage A that has flowed into the manhole 5 from the sewer pipe 3 by 6 am is accompanied by unknown water (specifically, infiltration groundwater). It is considered that domestic wastewater is also included. In FIG. 5, the manhole pump 9 operates at 1:00 am for the first time and thereafter does not operate until the second operation after 5:00 am. Since it is considered that almost no domestic wastewater is discharged from 1 am to 5 am, sewage A flowing from sewer pipe 3 into manhole 5 from 1 am to after 5 am is unknown water (specifically For example, it is considered to be only the infiltrated groundwater of the constantly infiltrated water). Therefore, the unknown water amount can be obtained by dividing the pump-up amount of one time by the time between the first operation and the second operation. In FIG. 6, the stop time of the manhole pump 9 is almost 30 minutes from 11:00 am to 3:00 pm. It is considered that this is affected by the infiltration of rainwater into the sewer pipe 3 due to rainfall after 11:00 am. Assuming that the average stop time of the manhole pump 9 during fine weather from 11:00 am to 3:00 pm is, for example, 2 hours, one pump up amount is divided by a value obtained by dividing one pump up amount by 30 minutes. It is considered that the amount obtained by subtracting the value obtained by dividing the value by 120 minutes is the unknown water amount (specifically, the amount of infiltrated water in rainy weather or the amount of infiltrated rainwater).

1 Pump facility 3 Sewer pipe 5 Manhole 9 Manhole pump 17 Control device 19 Cable 21 Clamp type AC current sensor

Claims (3)

An unknown water estimation method for estimating the amount of unknown water flowing into a sewer,
Detecting the drive current supplied to the manhole pump provided in the manhole of the pump facility provided in the sewer pipe,
Based on the detected drive current, the operating time of the manhole pump is specified and recorded,
Determine the sewage flow rate flowing into the manhole in a predetermined time zone based on the operating time zone of the recorded manhole pump,
Is to estimate the unknown water amount based on the determined sewage flow rate ,
For detecting the drive current supplied to the manhole pump, a clamp type AC current sensor is connected to a cable or a cord for supplying the drive current to the manhole pump in a control panel provided in the pump facility. Done by
The unknown water estimation method , wherein the sewage flow rate is determined based on a time between the operating hours of the manhole pump and a single pump-up water amount of the manhole pump . The unknown water estimation method according to claim 1, wherein the determined sewage flow rate flowing into the manhole is during a period in which domestic wastewater is not discharged. The sewage flow rate flowing into the manhole to be determined is during rain and fine weather in the same time period,
The unknown water estimation method according to claim 1, wherein the unknown water amount is estimated by subtracting the sewage flow rate in the fine weather from the sewage flow rate in the rainfall.

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