Pressure Detection System

Abstract

To provide a pressure detection system with which it is possible to detect a pressure of a plurality of portions to be measured, easily and suppressing errors.SOLUTION: A pressure detection system 21 comprises pressure sensors 23a-23h, a reference sensor 24, a gas sending unit 27, a flow channel control unit 28, and an acquisition arithmetic unit 29. The reference sensor 24 serves as a reference for calibration that is used in calibrating the pressure sensors 23a-23h that measure a pressure of the portions to be measured. The gas sending unit 27 sends a gas to the reference sensor 24 and the pressure sensors 23a-23h, respectively, and the flow channel control unit 28 controls on / off of sending a gas to the pressure sensors 23a-23h and the reference sensor 24. The acquisition arithmetic unit 29 calibrates the pressure sensors 23a-23h on the basis of a pressurized pressure value having been pressurized by the gas and detected by the reference sensor 24 and the pressure sensors 23a-23h and a non-pressurized pressure value having been depressurized and detected by the reference sensor 24 and the pressure sensors 23a-23h.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a pressure detection system.

Background Art

[0002] For example, in a dam, the pumping water pressure (uplift pressure) is measured to monitor the safety of the dam. The pumping water pressure is measured by providing a pressure gauge connected to each of a plurality of drain holes provided in the inspection gallery of the dam body.

[0003] In order to measure the pumping water pressure, it is necessary to perform opening and closing operations of a plurality of valves provided in the pipe connecting the drain hole and the pressure gauge, and it also takes a great deal of labor and time such as having to read the pointer of the pressure gauge after a predetermined time has elapsed since the opening and closing switching.

[0004] For measuring the pumping water pressure, for example, Bourdon tube pressure gauges are often used as pressure gauges. In the case of a Bourdon tube pressure gauge, measurement is performed by so-called pointer reading to read the pointer indicating the detected pressure, so errors are likely to occur by the operator who performs the pointer reading. Therefore, there is also a method of detecting the pumping water pressure using a pressure sensor, but there are errors for each pressure sensor, and the error of the pressure sensor also fluctuates over time.

[0005] Patent Document 1 describes a method of calibrating chamber pressure sensors provided in each of a plurality of chambers in order to detect the pressure of each of the plurality of chambers with the pressure sensors. This method sends gas into the plurality of chambers and calibrates the selected chamber pressure sensor so as to eliminate the difference between the pressure measurement value of the selected chamber pressure sensor equal to the average value of the plurality of first pressure measurement values and the average value of the plurality of second pressure measurement values.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, since the method of Patent Document 1 sends gas to a plurality of chambers, it cannot be adopted in a narrow area such as a drain hole in an inspection corridor. Further, in the method of Patent Document 1, it is necessary to obtain the average value of a plurality of first pressure measurement values and a plurality of second pressure measurement values respectively, and the calibration process is complicated.

[0008] Therefore, an object of the present invention is to provide a pressure detection system capable of simply detecting the pressures of a plurality of measured parts while suppressing errors.

Means for Solving the Problems

[0009] The pressure detection system of the present invention includes a plurality of pressure sensors, a reference sensor, a gas delivery unit, a gas feed control unit, and a calibration calculation unit. The plurality of pressure sensors respectively measure the pressures of a plurality of measured parts. The reference sensor serves as a calibration reference for calibrating the pressure sensors. The gas delivery unit delivers gas to each of the reference sensor and the pressure sensor to be calibrated. The gas feed control unit controls the on and off of the feeding of the gas to the plurality of pressure sensors and the reference sensor. The calibration calculation unit calibrates the pressure sensors based on the pressurized pressure values detected by the reference sensor and the pressure sensors in a state where the pressure is increased to a target pressure value by gas, and the non-pressurized pressure values detected by the reference sensor and the pressure sensors in a state where the pressurization by gas is released. The reference sensor and each of the plurality of pressure sensors are connected in parallel to the gas delivery section by a guide pipe for guiding the gas. The guide pipe has a main line extending from the gas delivery section and a plurality of pressure sensor lines, one end of each of which is connected to the main line and the other end of each of which is connected to a pressure sensor. The pressure detection system further includes a pipe to be measured, a branched pipe to be measured, a first valve, a second valve, and a third valve. One end of the pipe to be measured is connected to the pressure sensor line, and the other end thereof is connected to the portion to be measured. The branched pipe to be measured branches from the pipe to be measured, and the tip thereof is open. The first valve is provided on the side of the portion to be measured rather than the branching position of the pipe to be measured where the branched pipe to be measured branches. The second valve is provided in the branched pipe to be measured. The third valve is provided on the side of the main line rather than the connection position of the pressure sensor line where the pipe to be measured is connected.

[0010] The pressure detection system of the present invention includes a plurality of pressure sensors, a reference sensor, a gas delivery unit, a gas feed control unit, a calibration calculation unit, a first delivery valve and a second delivery valve, a delivery branch pipe, and a branch valve. The plurality of pressure sensors respectively measure the pressures of a plurality of parts to be measured. The reference sensor serves as a calibration reference for calibrating the pressure sensors. The gas delivery unit delivers gas to each of the reference sensor and the pressure sensor to be calibrated. The gas feed control unit controls the on and off of the feeding of the gas to the plurality of pressure sensors and the reference sensor. The calibration calculation unit calibrates the pressure sensors based on the pressurized pressure values detected by the reference sensor and the pressure sensors in a state where the pressure is increased to the target pressure value by the gas, and the non-pressurized pressure values detected by the reference sensor and the pressure sensors in a state where the pressurization by the gas is released. The reference sensor and each of the plurality of pressure sensors are connected in parallel to the gas delivery unit by a guide pipe for guiding the gas. The first delivery valve and the second delivery valve are provided in series with each other in the guide pipe between the gas delivery unit and the reference sensor and the plurality of pressure sensors, and switch the on and off of the delivery of the gas from the gas delivery unit to the reference sensor and the plurality of pressure sensors. The delivery branch pipe branches from the guide pipe between the first delivery valve and the second delivery valve, and the tip is open. The branch valve is arranged in the delivery branch pipe. It is more preferable that the guide pipe has a main line extending from the gas delivery unit and a plurality of pressure sensor lines, one end of which is connected to the main line and the other end of which is connected to the pressure sensors. In this case, the pressure detection system includes a part to be measured pipe, a part to be measured branch pipe, a first valve, a second valve, and a third valve. One end of the part to be measured pipe is connected to the pressure sensor line, and the other end is connected to the part to be measured. The part to be measured branch pipe branches from the part to be measured pipe, and the tip is open. The first valve is provided on the side of the part to be measured rather than the branch position of the part to be measured pipe where the part to be measured branch pipe branches. The second valve is provided in the part to be measured branch pipe. The third valve is provided on the side of the main line rather than the connection position of the pressure sensor line where the part to be measured pipe is connected.

[0011] In the calibration calculation unit in the above pressure detection system, it is preferable to calibrate the pressure sensor by making the maximum detection pressure correspond to the pressurized pressure of the pressure sensor with respect to the pressurized pressure of the reference sensor, and making the minimum detection pressure correspond to the non-pressurized pressure of the pressure sensor with respect to the non-pressurized pressure of the reference sensor.

[0012] The pressure detection system of the present invention includes a plurality of pressure sensors, a reference sensor, a gas delivery unit, a gas feed control unit, and a calibration calculation unit. The plurality of pressure sensors respectively measure the pressures of a plurality of measured parts. The reference sensor serves as a calibration reference for calibrating the pressure sensor. The gas delivery unit delivers gas to each of the reference sensor and the pressure sensor to be calibrated. The gas feed control unit controls the on and off of the feeding of the above gas to the plurality of pressure sensors and the reference sensor. The calibration calculation unit calibrates the pressure sensor based on the pressurized pressure values detected by the reference sensor and the pressure sensor in a state where they are pressurized to the target pressure values by the gas, and the non-pressurized pressure values detected by the reference sensor and the pressure sensor in a state where the pressurization by the gas is released. The calibration calculation unit calibrates the pressure sensor by making the maximum detection pressure correspond to the pressurized pressure of the pressure sensor with respect to the pressurized pressure of the reference sensor, and making the minimum detection pressure correspond to the non-pressurized pressure of the pressure sensor with respect to the non-pressurized pressure of the reference sensor. 。

[0013] It is preferable that the reference sensor and each of the plurality of pressure sensors are connected in parallel to the gas delivery unit by a guide pipe that guides the above gas. It is preferable to include an overall controller that controls the gas feed control unit and the calibration calculation unit.

Effects of the Invention

[0014] According to the present invention, the pressures of a plurality of measured parts can be detected simply and with error suppression.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0016] An embodiment of the present invention will be described by taking a pressure detection system for detecting the pumping water pressure (uplift pressure) of a dam in a hydropower plant as an example. The pressure detection system can detect pressures at a plurality of locations. The pressure detection system is not limited to measuring the pumping water pressure of a dam. For example, it can also be used to detect the pressures of oil and natural gas flowing through the pipelines of oil and natural gas, the pressures inside the pipes and tanks at natural gas mining sites, the pressures inside the pipes, tanks and distillation towers in oil plants, the pressures inside the fermentation tanks in wine production, etc., and is suitable for detecting static pressure as in this example.

[0017] A plurality of drain holes 14a to 14h are provided at intervals in the direction in which the inspection gallery 18 extends in the dam embankment 13. Each of the drain holes 14a to 14h has one end opening to the ground (rock mass) 17 under the dam embankment 13 and the other end opening in the inspection gallery 18. The pressure detection system includes a plurality of pressure sensors for detecting the uplift pressure, and the pressure sensors are provided connected to the openings on the inspection gallery 18 side of each of the drain holes 14a to 14h. Thereby, the uplift pressure at each location in the dam embankment 13 is detected. The detected uplift pressure is transmitted to an external controller provided in the management building 19 that manages the dam via a master controller (described later) provided in the inspection gallery 18. Thus, according to the pressure detection system, the detected uplift pressure is notified to the management building 19. In the following description, when the drain holes 14a to 14h are not distinguished, they are referred to as drain holes 14.

[0018] In the example shown in FIG. 1, since a pressure detection system is provided in a dam having eight drain holes 14, the number of pressure sensors is set to eight. However, the number of pressure sensors may be appropriately set according to the number of detection locations for detecting the uplift pressure. In FIG. 1, reference signs PSa to PSh are assigned to the installation positions of the pressure sensors, reference sign PC is assigned to the installation position of the master controller, and reference sign PU is assigned to the installation position of the calibration unit used for calibrating each pressure sensor. The installation position of the calibration unit is not particularly limited. However, the calibration unit in this example includes a reference sensor for calibrating the pressure sensor, and the reference sensor is arranged at the lowest position in the inspection gallery 18 as a position where the influence of atmospheric pressure and its fluctuations is most suppressed. In the example shown in FIG. 1, the management building 19 is provided at approximately the same height as the top end 13u of the dam embankment 13, but the position of the management building 19 varies depending on the dam.

[0019] In FIG. 2, the pressure detection system 21 is for calibrating pressure sensors 23a, 23b, 23c, ···, 23h and measuring the pumping pressure using the calibrated pressure sensors 23a, 23b, 23c, ···, 23h. The pressure detection system 21 includes pressure sensors 23a, 23b, 23c, ···, 23h, a reference pressure sensor (hereinafter referred to as a reference sensor) 24, a gas delivery unit 27, a flow path control unit 28, and an acquisition calculation unit 29. The pressure detection system 21 preferably further includes a general controller 31 and an external controller 32, and this is also the case in this example.

[0020] Each of the pressure sensors 23a to 23h and the reference sensor 24 is connected to the acquisition calculation unit 29 by, for example, an optical cable or the like, and outputs the detected pressure to the acquisition calculation unit 29. The acquisition calculation unit 29 acquires the detected values of the pressure from the pressure sensors 23a to 23h and the reference sensor 24, and performs predetermined processes such as calibration of the pressure sensors 23a to 23h and output to the overall controller 31. The first to ninth valves V1 to V9 and the gas delivery unit 27 provided in the respective pipes TA, TB, TC, TD connecting the gas delivery unit 27, the pressure sensors 23a to 23h, and the reference sensor 24, and the drain holes 14a to 14h are controlled by a flow path control unit 28 connected by, for example, an optical cable or the like. The overall controller 31 comprehensively controls the flow path control unit 28 and the acquisition calculation unit 29. The external controller 32 is connected to the overall controller 31 by, for example, an optical cable or the like, and appropriately gives various control instructions to the overall controller 31. An input unit 35 is provided in the overall controller 31, and an input unit 36 is provided in the external controller 32. Based on the input operations by the input units 35 and 36, various control settings of the overall controller 31 and the external controller 32 can be made. Further, a display unit 37 is provided in the overall controller 31, and a display unit 38 is provided in the external controller 32. Images for input operations at the input units 35 and 36, the states of each unit, the pressure detection values detected by the pressure sensors 23a to 23h, and the like are displayed. The display images are generated by the overall controller 31 and the external controller 32, respectively. Hereinafter, each part of the pressure detection system 21 will be described in detail.

[0021] The pressure sensor 23a is for detecting the pressure at the drain hole 14a (the pressure of water or gas coming out of the drain hole 14a) as the pumping pressure, and together with the first to third valves V1 to V3 and the like, it constitutes the detection unit SUa. Similarly, the pressure sensors 23b to 23h are for detecting the pressure at the drain holes 14b to 14h as the pumping pressure. The pressure sensors 23b to 23h also constitute the detection units Sub to Svh together with the same first to third valves V1 to V3 as the first to third valves V1 to V3 of the detection unit SUa. However, for each of the detection units Sub to Svh, since the configuration is the same as that of the detection unit SUa, the illustration of the first to third valves V1 to V3 is omitted.

[0022] The pressure sensors 23a to 23h in this example detect the pumping pressure, which is the water pressure at the drain hole 14, as the pressure of the measured part. However, as described above, a pressure different from the pumping pressure of the dam can be detected as the pressure of the measured part. The pressure sensors 23a to 23h in this example are pressure sensors that detect the so-called gauge pressure based on the atmospheric pressure. Also, the pressure sensors 23a to 23h in this example are semiconductor pressure sensors (semiconductor diaphragm pressure sensors), but other pressure sensors, such as strain gauge type pressure sensors or thin film type pressure sensors, may also be used. However, the plurality of pressure sensors 23a to 23h are preferably the same pressure sensors as each other and have the same range (measurement range). In this example, the high-precision small-sized pressure transmitters FP201 manufactured by Yokogawa Electric Corporation are used as the pressure sensors 23a to 23h. The pressure sensors 23a to 23h output the detected pressure detection values to the acquisition calculation unit 29.

[0023] The reference sensor 24 is a pressure sensor that serves as a calibration reference for calibrating each of the pressure sensors 23a to 23h. Since the reference sensor 24 is a pressure sensor serving as a calibration reference, it is preferably one with as small an error as possible and capable of detecting pressure precisely. By using such a reference sensor 24, the pressure sensors 23a to 23h detect pressure after being precisely calibrated with the reference sensor 24, so they can function sufficiently even if they cannot detect with the same precision as the reference sensor 24. Therefore, when pressure sensors are already provided in each drain hole 14, those pressure sensors may be used as the pressure sensors 23a to 23h.

[0024] The reference sensor 24 is a pressure sensor that detects gauge pressure in the same manner as a pressure sensor. The pressure sensor used for the reference sensor 24 preferably has the same range as the pressure sensors 23a to 23h, and is preferably of higher quality with an accuracy one digit or more better than that of the pressure sensors 23a to 23h. Also, although the reference sensor 24 in this example is a semiconductor pressure sensor (semiconductor diaphragm pressure sensor), other pressure sensors such as a strain gauge type pressure sensor or a thin film type pressure sensor may be used in the same manner as the pressure sensors 23a to 23h. In this example, a pressure transmitter EJX430J manufactured by Yokogawa Electric Corporation is used as the reference sensor 24. The reference sensor 24 constitutes a calibration unit CU together with a gas delivery unit 27 and valves V4 to V9, etc., and outputs the detected pressure detection value to an acquisition calculation unit 29.

[0025] The gas delivery unit 27 that constitutes the calibration unit CU together with the reference sensor 24 is for pressurizing each of the reference sensor 24 and the pressure sensors 23a to 23h when calibrating the pressure sensors 23a to 23h. The gas delivery unit 27 delivers air (as an example of the gas used for pressurization, pressurized gas) to each of the reference sensor 24 and the pressure sensors 23a to 23h. The gas delivery unit 27, the reference sensor 24, and the pressure sensors 23a to 23h are connected by a guide pipe TA for guiding air, and the air sent out from the gas delivery unit 27 is guided to each of the reference sensor 24 and the pressure sensors 23a to 23h by this guide pipe TA.

[0026] The gas delivery unit 27 includes a compressor 41, an air filter 42, and a regulator 43. The compressor 41 compresses the intake air under the control of the flow path control unit 28 to increase the pressure and then delivers it. The air filter 42 removes dust from the air sent from the compressor 41 to purify it. The air filter 42 may be omitted, but it is preferably provided to prevent dust from entering each valve and device on the downstream side in the air delivery direction. The regulator 43 is arranged downstream of the air filter 42 in the air delivery direction and performs pressure adjustment to reduce the pressure of the air from the compressor 41. Note that the compressor 41, the air filter 42, and the regulator 43 may be integrally formed. Instead of the compressor 41, other air blowing devices such as a blower or a fan that delivers air at a lower pressure than the compressor 41 may be used. When a blower or a fan is used, the regulator 43 may not be provided.

[0027] The compressor 41 in this example is a so-called air compressor that pressurizes and delivers the intake air, but it may also be a compressor that pressurizes and delivers a gas other than air. Examples of gases other than air include inert gases such as nitrogen and rare gases (helium, argon, etc.). Further, instead of the compressor 41, a cylinder or the like that compresses and stores a gas other than air and can adjust the delivery flow rate may be used.

[0028] The gas delivery unit 27 is connected to each of the reference sensor 24 and the pressure sensors 23a to 23h and a guide pipe TA that guides the air delivered from the compressor 41. Thereby, the air delivered from the compressor 41 is surely sent to the reference sensor 24 and the pressure sensors 23a to 23h without waste, and since it is guided in a space with a very small volume of the pipe, it is sent quickly and the calibration process proceeds quickly.

[0029] The reference sensor 24 and each of the pressure sensors 23a to 23h are preferably connected in parallel to the gas delivery unit 27 by a guide pipe TA, and this is also the case in this example. The guide pipe TA includes a main line TAm extending from the compressor 41, a reference sensor line TAr having one end connected to the main line TAm, and a plurality of pressure sensor lines TAs. The pressure sensor lines TAs are provided for each of the pressure sensors 23a to 23h, and there are 8 lines in this example. The connection position where the reference sensor line TAr and the main line TAm are connected is defined as connection position P21, and the connection position where the pressure sensor lines TAs and the main line TAm are connected is defined as connection position P22.

[0030] A fourth valve V4 and a fifth valve V5 are provided in series with each other in the main line TAm between the gas delivery unit 27 and the reference sensor 24 and the pressure sensors 23a to 23h. Among these, the upstream side in the air delivery direction from the gas delivery unit 27 is the fourth valve V4, and the downstream side is the fifth valve V5. The fourth valve V4 and the fifth valve V5 are each an example of a first delivery valve and a second delivery valve for switching on (delivery) and off (non-delivery) of the air delivery to the reference sensor 24 and the pressure sensors 23a to 23h, and open and close the main line TAm under the control of the flow path control unit 28. The fourth valve V4 and the fifth valve V5 are electromagnetic valves in this example.

[0031] A delivery branch pipe TB with an open tip branches from the main line TAm between the fourth valve V4 and the fifth valve V5, and the branching position is defined as branch position P23. A sixth valve V6 is arranged in the delivery branch pipe TB, and the sixth valve V6 opens and closes the delivery branch pipe TB under the control of the flow path control unit 28. When the sixth valve V6 is in the closed state while air is being delivered from the gas delivery unit 27, the entire amount of air is guided to the reference sensor 24 and the pressure sensors 23a to 23h. When the delivery of air from the gas delivery unit 27 is off and the sixth valve V6 is in the open state, the secondary side of the compressor 41 is opened and the residual pressure is released, returning to atmospheric pressure. By setting the sixth valve V6 to the closed state, the main line becomes airtight.

[0032] Preferably, a seventh valve V7 for adjusting the opening degree of the main line TAm is provided between the gas delivery section 27 and the fourth valve V4, and this is also the case in this example. The seventh valve V7 is for adjusting the flow rate of the air from the gas delivery section 27. The seventh valve V7 is not particularly limited as long as it can adjust the opening degree of the main line TAm, and in this example, it is a manual needle valve.

[0033] Preferably, an eighth valve V8 for adjusting the opening degree of the delivery branch pipe TB is provided on the tip side of the sixth valve V6 of the delivery branch pipe TB, and this is also the case in this example. The eighth valve V8 is for adjusting the speed of the above-mentioned residual pressure release in the compressor 41. The eighth valve V8 is not particularly limited as long as it can adjust the opening degree of the delivery branch pipe TB, and in this example, it is a manual needle valve.

[0034] Preferably, a ninth valve V9 for opening and closing the reference sensor line TAr is provided on the reference sensor line TAr, and this is also the case in this example. The ninth valve V9 is for separating the reference sensor line TAr from the main line TAm in a closed state when inspecting the reference sensor 24 (such as inspection for maintenance) and when calibrating the pressure sensor 23. The ninth valve V9 is not particularly limited as long as it can open and close the reference sensor line TAr, and in this example, it is a manual valve.

[0035] In the detection unit SUa, a third valve V3 is provided on each pressure sensor line TAs extending from the main line TAm to the pressure sensor 23a. The third valve V3 is for switching on and off the delivery of air to the pressure sensor 23a, and opens and closes the pressure sensor line TAs under the control of the flow path control unit 28.

[0036] In the detection unit SUa, a measurement target pipe TC having one end connected to the pressure sensor line TAs and the other end connected to the drain hole 14a, and a measurement target branch pipe TD branched from the measurement target pipe TC and having an open tip are provided. The position where the measurement target pipe TC and the pressure sensor line TAs are connected is defined as the connection position P24, and the position where the measurement target branch pipe TD of the measurement target pipe TC branches is defined as the branch position P25. The third valve V3 is provided on the main line TAm side of the pressure sensor line TAs with respect to the connection position P24.

[0037] A first valve V1 is provided on the drain hole 14a side with respect to the branch position P25 of the measurement target pipe TC. The first valve V1 opens and closes the measurement target pipe TC under the control of the flow path control unit 28.

[0038] A second valve V2 is provided in the measurement target branch pipe TD. The second valve V2 opens and closes the measurement target branch pipe TD under the control of the flow path control unit 28.

[0039] In the detection units Sub to SUh as well, the pressure sensor line TAs, the measurement target pipe TC, the measurement target branch pipe TD, and the first to third valves V1 to V3 are provided with the same configuration. In this example, the third valve V3 is an electromagnetic valve, and the first and second valves V1 and V2 are motor valves.

[0040] The flow path control unit 28 is an example of a gas feed control unit that controls the feeding of air from the gas delivery unit 27 to each of the reference sensor 24 and the pressure sensors 23a to 23h. Under the control of the overall controller 31, the flow path control unit 28 controls the opening and closing of each of the first to sixth valves V1 to V6 at a predetermined timing so that air flow paths are formed for bringing the reference sensor 24 and the pressure sensors 23a to 23h into a pressurized state for detecting target pressure values and a non-pressurized state in which the pressurized state is released, respectively, and also switches the drive of the compressor 41 of the gas delivery unit 27 between on and off to control the delivery of air. Also, under the control of the overall controller 31, the flow path control unit 28 opens and closes the first to third valves V1 to V3 at a predetermined timing to open and close the pressure sensor line TAs, the measured part pipe TC, and the measured part branch pipe TD on the inspection corridor 18 side of the drain hole 14, respectively, and forms a water guide path from the drain hole 14.

[0041] The acquisition calculation unit 29 is an acquisition unit that acquires the detected pressure values of the pressures detected by the reference sensor 24 and the pressure sensors 23a to 23h, and is also an example of a calibration calculation unit that calibrates the pressure sensors based on the detected pressure values. For example, when calibrating the pressure sensors 23a to 23h, the acquisition calculation unit 29 inputs the detected pressure values of the non-pressurized pressures (hereinafter referred to as non-pressurized pressure values) detected by the reference sensor 24 and the pressure sensors 23a to 23h in the non-pressurized state, and the detected pressure values of the pressurized pressures (hereinafter referred to as pressurized pressure values) detected by the reference sensor 24 and the pressure sensors 23a to 23h in the pressurized state, and calibrates the pressure sensors 23a to 23h based on the non-pressurized pressure values and the pressurized pressure values. The reference sensor 24 and the pressure sensors 23a to 23h in this example output a detection current corresponding to the detected pressure, and the value of this detection current is output to the acquisition calculation unit 29 as a detected pressure value such as a pressurized pressure value and a non-pressurized pressure value. The acquisition calculation unit 29 associates each non-pressurized pressure value of the pressure sensors 23a to 23h with the non-pressurized pressure value of the reference sensor 24, and sets this non-pressurized pressure value as the minimum detection pressure (zero point), and associates each pressurized pressure value of the pressure sensors 23a to 23h with the pressurized pressure value of the reference sensor 24, and sets this pressurized pressure value as the maximum detection pressure. Then, the acquisition calculation unit 29 performs an operation to adjust the difference between the maximum detection pressure and the minimum detection pressure for each of the pressure sensors 23a to 23h according to each range. In this way, the pressure sensors 23a to 23h are calibrated, and the correspondence between the detected pressure value before calibration and the detected pressure value after calibration is stored in a storage unit (not shown). Note that the reference sensor 24 and the pressure sensors 23a to 23h may output a detection voltage corresponding to the detected pressure as a detected pressure value such as a pressurized pressure value and a non-pressurized pressure value to the acquisition calculation unit 29.

[0042] Also, when measuring the pumping pressure, when the detected pressure value is input from the pressure sensors 23a to 23h, the acquisition calculation unit 29 specifies the detected pressure value before calibration stored in the above storage unit. Then, the detected pressure value after calibration associated with the specified detected pressure value is output to the overall controller 31 as the value of the pumping pressure. Note that the acquisition calculation unit 29 has a time counter, and when the detected pressure value is input, the detected pressure value is output to the overall controller 31 in association with the date and time.

[0043] The overall controller 31 controls the flow path control unit 28 and the acquisition calculation unit 29 based on a preset sequence. The sequence and the timing of the execution of the sequence may be set in advance as an application program, or may be set by the input unit 35. The application program may be incorporated in the overall controller 31, or in addition to or instead of the overall controller 31, may be incorporated in the external controller 32. When it is incorporated only in the external controller 32, the overall controller 31 functions under the control of the external controller 32 and causes each part to execute the sequence. Also, when it is incorporated only in the external controller 32, the timing of the execution of the sequence may be set by the input unit 36.

[0044] The overall controller 31 can generate various display images such as a data image for displaying various data such as an image (input image) for setting a sequence etc. by the input unit 35, the state of each part of the pressure detection system 21, and the pressure detection values input from the reference sensor 24 and the pressure sensors 23a to 23h, and display them on the display unit. The overall controller 31 may also include a storage unit (not shown) for storing the past pressure detection values input from the pressure sensors 23a to 23h as history data together with the input date and time, and in this example, it is also done in this way. And the overall controller 31 of this example can generate a list display image for displaying these history data in a list, and a graph display image obtained by graphing the history data as time-series data, and display the list display image and the graph display image on the display unit 37.

[0045] The overall controller 31 in this example is connected to an external controller 32. As a result, the overall controller 31 is configured to be able to output to the external controller 32 the states of each part of the input pressure detection system 21, various data, data of various generated display images, and the like. Therefore, when a transmission instruction for these data is input from the external controller 32 to the overall controller 31, these data are transmitted from the overall controller 31 to the external controller 32 based on this transmission instruction and can be displayed on the display unit 37. Note that the transmission instruction is input to the external controller 32, for example, by an input operation in the input unit 36.

[0046] The operation of the above configuration will be described. In the steady state, in the pressure detection system 21, the first to third valves V1 to V3 are in the open state, the fourth to sixth valves V4 to V6 are in the closed state, and the drive of the compressor 41 of the gas delivery unit 27 is turned off. Due to the states of the above valves, one end of the inspection corridor 18 side of the drain hole 14 is in an open state, and the state is such that water is discharged. The measurement of the pumping pressure and the calibration process for calibrating the pressure sensors 23a to 23h are performed under the control of the overall controller 31 arranged in the inspection corridor 18 or the external controller 32 arranged in the management building 19. In this way, in the pressure detection system 21, it is not necessary for an operator to perform the calibration process and the detection of the pumping pressure at each location of the plurality of drain holes 14 in the inspection corridor 18.

[0047] When measuring the pumping pressure, the pressure detection system 21 performs a calibration process on the pressure sensors 23a to 23h before detecting the pumping pressure. However, the timing for performing the calibration process may be appropriately set by the overall controller 31 or the external controller 32. For example, it may be set to be performed every time the pumping pressure is detected, or it may be set to be performed at a predetermined time interval such as every month, every two weeks, every second, etc., or it may be set to be performed at the target timing by the input unit 35 or the input unit 36. In this example, the detected pressure values are output from each of the reference sensor 24 and the pressure sensors 23a to 23h to the acquisition calculation unit 29 at a predetermined time interval.

[0048] When performing the calibration process of the pressure sensors 23a to 23h before detecting the pumping pressure, as shown in FIG. 3, the flow path control unit 28 first opens the fourth to sixth valves V4 to V6 (S1). Then, the acquisition calculation unit 29 stores the detected pressure values obtained from each of the reference sensor 24 and the pressure sensors 23a to 23h (S2) in the storage unit as non-pressurized pressure values.

[0049] Next, the flow path control unit 28 closes the first, second, and sixth valves V1, V2, and V6 (S3). Subsequently, the flow path control unit 28 starts sending air by turning on the compressor 41 (S4) to pressurize the reference sensor 24 and the pressure sensors 23a to 23h. When the reference sensor 24 detects the target pressure value, the acquisition calculation unit 29 determines whether the detected pressure values of the reference sensor 24 and the pressure sensors 23a to 23h are stable (S5). If it is determined that they are not stable, the pressurization by air supply continues. If it is determined that they are stable, an affirmative determination result indicating stability is output to the flow path control unit 28 via the overall controller 31. When this affirmative determination result is input, the flow path control unit 28 closes the fifth valve V5 (S6) to make the guide pipe TA airtight.

[0050] The flow path control unit 28 turns off the drive of the compressor 41 (S7) and opens the sixth valve V6 (S8). Note that the order of S7 and S8 may be reversed. After that, the acquisition calculation unit 29 stores the detected pressure values obtained from each of the reference sensor 24 and the pressure sensors 23a to 23h (S9) in the storage unit as pressurized pressure values. Then, the acquisition calculation unit 29 performs calibration processing for each of the pressure sensors 23a to 23h based on the non-pressurized pressure values and the pressurized pressure values stored in the storage unit (S10). For example, when the non-pressurized pressure value of the reference sensor 24 is obtained as 0 kPa and the non-pressurized pressure value of the pressure sensor 23a is obtained as a pressure value of 0.1 kPa, the non-pressurized pressure value of the pressure sensor 23a is calibrated to the minimum detection pressure of 0 kPa in accordance with the non-pressurized pressure value of the reference sensor 24. Similarly, for the pressure sensors 23b to 23h, the non-pressurized pressure value is calibrated to 0 kPa in accordance with the non-pressurized pressure value of the reference sensor 24. Also, the calibration of the pressurized pressure value is the calibration of the maximum detection pressure value (full scale value) when pressurized to the maximum pressure in each of the above steps S4, S5, S6, S7, and S8. For example, when using the reference sensor 24 with a full scale value of 300 kPa and the pressure sensor 23a, in step S4, the reference sensor 24 is pressurized with the target pressure value of 300 kPa as described above. When the pressurized pressure values of the similarly pressurized pressure sensors 23a to 23h are obtained as 285 kPa, the pressurized pressure value is calibrated to the maximum detection pressure of 300 kPa in accordance with the pressurized pressure value of the reference sensor 24. That is, the pressure sensor 23a is calibrated from a range of 0.1 kPa to 285 kPa to a range of 0 kPa to 300 kPa. Similarly, for the pressure sensors 23b to 23h, the pressurized pressure value is calibrated to 300 kPa in accordance with the pressurized pressure value of the reference sensor 24.

[0051] The acquisition calculation unit 29 calibrates the pressure sensors 23a to 23h based on the pressurized pressure values and non-pressurized pressure values detected by the reference sensor 24 and the pressure sensors 23a to 23h, and obtains the reference sensor 24 and the pressure sensors 23a to 23h for obtaining the pressurized pressure values and non-pressurized pressure values. The supply of air is switched on and off under the control of the overall controller 31. As a result, it is simple and there is no need for an operator to open and close a valve for calibration at the pressure sensors 23a to 23h in the inspection gallery 18 during the calibration process. Further, since the detected pressure values are sent from the pressure sensors 23a to 23h to the overall controller 31 and the external controller 32 via the acquisition calculation unit 29, the pressurized pressure values, non-pressurized pressure values, and pumping pressure are respectively reported to the installation position PC in the inspection gallery 18 or the management building 19. Therefore, the detection result of the pumping pressure can be known without working in the inspection gallery 18, and detection errors caused by reading the needle as in the case of using a Bourdon tube pressure gauge or the like are prevented. Furthermore, since the pressure sensors 23a to 23h detect the pumping pressure after being calibrated, the error is suppressed. Also, during calibration, if the pressurized pressure value of the reference sensor 24 is set to the maximum pressure value detected by the reference sensor 24, the control of pressurizing the reference sensor 24 with air only needs to pressurize the reference sensor 24 to the maximum, so it is not necessary to precisely control the air delivery flow rate or the like, and it is simple.

[0052] Also, since each of the reference sensor 24 and the pressure sensors 23a to 23h is connected in parallel to the gas delivery unit 27 by the guide pipe TA, when air from the compressor 41 is sent in, each of the reference sensor 24 and the pressure sensors 23a to 23h is pressurized to the same pressure. Further, when calibrating only an arbitrary part of the pressure sensors 23a to 23h, air can be sent only to the part for calibration, and the part can be pressurized to the same pressure as the reference sensor 24 more quickly than when sending air to all the pressure sensors 23a to 23h.

[0053] Since the pressure detection system is equipped with the fourth to sixth valves V4 to V6, it can protect the secondary side of the gas delivery unit 27 from sudden pressure changes and quickly pressurize and release the pressure of the reference sensor 24 and the pressure sensors 23a to 23h. Further, since the fourth to sixth valves V4 to V6 are unitized together with the reference sensor 24 and the gas delivery unit 27 to form the calibration unit CU, an operator can perform inspection and maintenance work on the reference sensor 24 together with the fourth to sixth valves V4 to V6 near the reference sensor 24 without moving around in the inspection corridor 18.

[0054] After the calibration process (S10), the flow path control unit 28 closes the fourth valve V4 (S11) to protect the compressor 41, and then opens the fifth valve V5 (S12). In step S12, it is more preferable to gradually reduce the pressure in the guide pipe TA by setting the opening degree of the fifth valve V5 to an open state smaller than the fully open state. In that case, it is assumed that the flow path control unit 28 can control the opening degree of the valve V5. Subsequently, an abnormality determination is made by measuring the difference between the reference sensor 24 and the pressure sensors 23a to 23h (S13). The abnormality determination in step S13 can be performed, for example, as follows. First, after step S12, the reference sensor 24 detects that the pressure in the guide pipe TA has reached approximately 3 / 4, 2 / 4, and 1 / 4 of the maximum pressure, and the pressure values at each of the pressure sensors 23a to 23h at these respective time points are detected. Then, the pressure value detected by the reference sensor 24 is compared with the pressure values detected by each of the pressure sensors 23a to 23h, and it is determined whether the error between the reference sensor 24 and the pressure sensors 23a to 23h is equal to or greater than a threshold value (1% in this example) as an abnormality determination for the pressure sensors 23a to 23h. If it is equal to or greater than the threshold value, it is determined as abnormal, and if it is less than the threshold value, it is determined as normal. For the pressure sensor determined to be abnormal, it is not used for measuring the pumping pressure, or even if it is measured, the measurement result is not adopted. Incidentally, the above error is obtained by {|P24 - P23| / P24} × 100 when the pressure value at the reference sensor 24 is P24 and the pressure values at the pressure sensors 23a to 23h are P23.

[0055] Next, after opening the first and second valves V1 and V2 and closing the third, fifth, and sixth valves V3, V5, and V6 (S14), the fifth and sixth valves V5 and V6 are opened (S15). Then, the second valve V2 is closed (S16) to connect the flow path of the non-measurement unit pipe TC to the drain hole 14. The overall controller 31 determines (S17) whether the elapsed time since the second valve V2 was closed has reached a preset predetermined time (for example, 60 minutes) or more. In the case of a negative determination, it waits for the passage of time until the predetermined time is reached. In the case of an affirmative determination, it sends an output instruction to the acquisition calculation unit 29 to specify the pressure detection values from the pressure sensors 23a to 23h as the pumping pressure and output them to the overall controller 31. In response to this output instruction, the acquisition calculation unit 29 acquires the pumping pressure (S18) and outputs it to the overall controller 31 together with the date and time. When the pumping pressure is input, the overall controller 31 stores it in the storage unit as pumping pressure data together with the date and time, and displays it on the display unit 37 in response to a display instruction or the like from the input unit 35.

[0056] Thereafter, after the flow path control unit 28 opens the second valve V2 (S19), it opens the third valve V3 and closes the fifth and sixth valves V5 and V6 (S20). As a result, the first to sixth valves V1 to V6 return to the initial state before the calibration process and the measurement of the pumping pressure, that is, the steady state.

Explanation of Signs

[0057] 14a~14h Drain holes 21 Pressure detection system 23a~23h Pressure sensors 24 Reference sensor 27 Gas delivery unit 28 Flow path control unit 29 Acquisition calculation unit 31 Overall controller P21, P22, P24 Connection positions P23, P25 Branch positions TA Guide pipe TAm Main line TAr Reference sensor line TAs Pressure sensor line TB Delivery Manifold TC Measured Part Pipe TD Measured Part Manifold V1 to V9 Valves 1 to 9

Claims

1. A plurality of pressure sensors each measuring a pressure of a plurality of measurement targets; a reference sensor serving as a calibration reference used for calibrating the pressure sensor; a gas delivery unit that delivers gas to each of the reference sensor and the pressure sensor to be calibrated; a gas supply control unit that controls on / off of the supply of the gas to the plurality of pressure sensors and the reference sensor; a calibration calculation unit that calibrates the pressure sensor based on a pressurized pressure value detected by the reference sensor and the pressure sensor in a state in which the pressure is pressurized to a target pressure value by the gas, and a non-pressurized pressure value detected by the reference sensor and the pressure sensor in a state in which the pressurization by the gas is released, the reference sensor and each of the plurality of pressure sensors are connected in parallel to the gas delivery section by a guide tube that guides the gas; the guide pipe includes a main line extending from the gas delivery portion, and a plurality of pressure sensor lines, one end of which is connected to the main line and the other end of which is connected to the pressure sensor; a measurement target pipe having one end connected to the pressure sensor line and the other end connected to a measurement target; A branch pipe of a measurement target portion which branches off from the measurement target pipe and has an open tip; A first valve is provided on the side of the measured portion relative to a branching position of the measured pipe where the measured portion branch pipe branches off; A second valve provided in the branch pipe of the measurement target portion; a third valve provided on the pressure sensor line closer to the main line than a connection position to which the measured pipe is connected; The pressure detection system further comprises:

2. A plurality of pressure sensors each measuring the pressure of a plurality of measurement targets; a reference sensor serving as a calibration reference used for calibrating the pressure sensor; a gas delivery unit that delivers gas to each of the reference sensor and the pressure sensor to be calibrated; a gas supply control unit that controls on / off of the supply of the gas to the plurality of pressure sensors and the reference sensor; a calibration calculation unit that calibrates the pressure sensor based on a pressurized pressure value detected by the reference sensor and the pressure sensor in a state in which the pressure is pressurized to a target pressure value by the gas, and a non-pressurized pressure value detected by the reference sensor and the pressure sensor in a state in which the pressurization by the gas is released, the reference sensor and each of the plurality of pressure sensors are connected in parallel to the gas delivery section by a guide tube that guides the gas; a first delivery valve and a second delivery valve that are provided in series with each other in the guide tube between the gas delivery unit, and the reference sensor and the plurality of pressure sensors, and that switch on and off delivery of the gas from the gas delivery unit to the reference sensor and the plurality of pressure sensors; a delivery section branch pipe that branches off from the guide pipe between the first delivery valve and the second delivery valve and has an open tip; A branch valve disposed in the delivery section branch pipe; A pressure detection system comprising:

3. the guide pipe includes a main line extending from the gas delivery portion, and a plurality of pressure sensor lines, one end of which is connected to the main line and the other end of which is connected to the pressure sensor; a measurement target pipe having one end connected to the pressure sensor line and the other end connected to a measurement target; A branch pipe of a measurement target portion which branches off from the measurement target pipe and has an open tip; A first valve is provided on the side of the measured portion relative to a branching position of the measured pipe where the measured portion branch pipe branches off; A second valve provided in the branch pipe of the measurement target portion; a third valve provided on the pressure sensor line closer to the main line than a connection position to which the measured pipe is connected; The pressure sensing system of claim 2 further comprising:

4. The pressure detection system according to any one of claims 1 to 3, wherein the calibration calculation unit calibrates the pressure sensor by corresponding the pressurized pressure of the pressure sensor to the pressurized pressure of the reference sensor to obtain a maximum detectable pressure, and by corresponding the non-pressurized pressure of the pressure sensor to the non-pressurized pressure of the reference sensor to obtain a minimum detectable pressure.

5. A plurality of pressure sensors each measuring a pressure of a plurality of measurement targets; a reference sensor serving as a calibration reference used for calibrating the pressure sensor; a gas delivery unit that delivers gas to each of the reference sensor and the pressure sensor to be calibrated; a gas supply control unit that controls on / off of the supply of the gas to the plurality of pressure sensors and the reference sensor; a calibration calculation unit that calibrates the pressure sensor based on a pressurized pressure value detected by the reference sensor and the pressure sensor in a state in which the pressure is pressurized to a target pressure value by the gas, and a non-pressurized pressure value detected by the reference sensor and the pressure sensor in a state in which the pressurization by the gas is released, The calibration calculation unit calibrates the pressure sensor by corresponding the pressurized pressure of the pressure sensor to the pressurized pressure of the reference sensor to obtain a maximum detectable pressure, and by corresponding the non-pressurized pressure of the pressure sensor to the non-pressurized pressure of the reference sensor to obtain a minimum detectable pressure.

6. 6. The pressure detection system according to claim 5, wherein the reference sensor and each of the plurality of pressure sensors are connected in parallel to the gas delivery section by a guide tube that guides the gas.

7. 7. The pressure detection system according to claim 1, further comprising an overall controller that controls the gas supply control unit and the calibration calculation unit.

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