JP2023137864A - Method for measurement, calculation device, and calculation program - Google Patents

Abstract

To easily measure the temperature of the inside of a tunnel in which a cable is set.SOLUTION: A method for measuring the inside of a tunnel in which a cabe is set includes the steps of: measuring a cable surface temperature as the temperature of the surface of a cable and the temperature of a wall surface of the tunnel by using a contactless technique; and calculating the temperature inside the tunnel as the temparature of the inside of the tunnel by performing a thermal analysis using the measured cable surface temperature and the measured wall surface temperature as a boundary condition.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a measurement method, a calculation device, and a calculation program.

Conventionally, techniques have been proposed for estimating the conductor temperature of cables installed underground.

For example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2004-264090) discloses the following conductor temperature estimation method. That is, the conductor temperature estimation method is a method for estimating the conductor temperature of a power cable in a conduit buried underground, and includes a step of measuring the temperature via a temperature sensor attached to the power cable at a predetermined distance. The conductor temperature TC is calculated using the temperature TP measured by the temperature sensor, the insulator thermal resistance R1, the anticorrosion layer thermal resistance R2, the surface dissipation thermal resistance R3, the conductor calorific value WC, the dielectric loss Wd, and the sheath loss WS. and a step of doing so.

Further, Patent Document 2 (Japanese Patent Laid-Open No. 2000-88666) discloses the following conductor temperature calculation method. In other words, the conductor temperature calculation method is a method for estimating the conductor temperature of a power cable in a conduit buried underground, and is based on the temperature inside the target conduit for which the conductor temperature is to be found, the temperature of the soil, and the energization of all conduits. The process of measuring the current value, calculating the surrounding thermal influence from the environment of the pipeline from Kennelly's equation based on the pipe size, installation position in the pipe, and soil thermal resistance value, and calculating the current flowing through each pipe. The step of determining the soil temperature change ΔT near the target pipe line by determining the heat flow value of the conductor from the value, and the calculated soil temperature Td from the base temperature Te and ΔT, which are the soil temperatures at each depth that change seasonally. A step of calculating the temperature inside the pipe according to an analytical model including the conductor temperature from this soil temperature Td and the heat flow value of the conductor in the target pipe, and a step of calculating the temperature inside the pipe based on the calculated value of the temperature inside the pipe and a step of comparing the measured value of the temperature in the road, and if the comparison results match, the conductor temperature used in the analysis model is output as the target calculated value of the conductor temperature, and if they do not match, the soil thermal resistance, Recalculate after reviewing the base temperature Te and the thermal constants used in the calculation.

JP2004-264090A Japanese Patent Application Publication No. 2000-88666

Beyond the techniques described in Patent Documents 1 and 2, a technique is desired that can easily measure the air temperature in a tunnel in which the cable is installed, in addition to the temperature of the conductor of the cable.

The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a measurement method, a calculation device, and a calculation program that can easily measure the temperature in a tunnel in which a cable is installed. That's true.

The measurement method of the present disclosure is a measurement method in a tunnel in which a cable is installed, and includes the steps of measuring a cable surface temperature that is the surface temperature of the cable and a wall temperature of the tunnel using a non-contact method. , calculating the temperature inside the tunnel, which is the temperature inside the tunnel, by performing a thermal analysis using the measurement results of the cable surface temperature and the wall surface temperature as boundary conditions.

The calculation device of the present disclosure is a calculation device that calculates the temperature inside a cave where a cable is installed, and measures the surface temperature of the cable and the wall temperature of the tunnel using a non-contact method. The apparatus includes an acquisition unit that acquires results, and a calculation unit that calculates the temperature inside the tunnel by performing thermal analysis using the measurement results acquired by the acquisition unit as a boundary condition.

The calculation program of the present disclosure is a calculation program used in a calculation device that calculates the temperature inside a tunnel in which a cable is installed, and the calculation program calculates the surface temperature of the cable using a non-contact method. an acquisition unit that acquires a measurement result of the wall surface temperature of the cave; and a calculation unit that calculates the temperature inside the cave by performing a thermal analysis using the measurement result acquired by the acquisition unit as a boundary condition. This is a program to make it work.

One aspect of the present disclosure can be realized not only as a calculation device including such a characteristic processing unit, but also as a calculation method including such characteristic processing as a step, or as a calculation device including a part of the calculation device or It can be realized as a semiconductor integrated circuit that realizes all of the above, or it can be realized as a measurement system including a calculation device.

According to the present disclosure, it is possible to easily measure the temperature inside a tunnel in which a cable is installed.

FIG. 1 is a diagram showing the configuration of a measurement system according to an embodiment of the present disclosure. FIG. 2 is a diagram showing the configuration of a calculation device according to an embodiment of the present disclosure. FIG. 3 is a diagram illustrating an example of a temperature distribution diagram created by the calculation unit in the calculation device according to the embodiment of the present disclosure. FIG. 4 is a diagram illustrating an example of a temperature graph created by the calculation unit in the calculation device according to the embodiment of the present disclosure. FIG. 5 is a flowchart defining an example of an operation procedure when creating a 3D model in the measurement system according to the embodiment of the present disclosure. FIG. 6 is a flowchart defining an example of an operation procedure when setting correction parameters in the measurement system according to the embodiment of the present disclosure. FIG. 7 is a flowchart that defines an example of an operation procedure when calculating the temperature inside the cave and the conductor temperature in the measurement system according to the embodiment of the present disclosure. FIG. 8 is a flowchart that defines an example of an operation procedure when predicting the temperature inside a cave and the conductor temperature in the measurement system according to the embodiment of the present disclosure.

First, the contents of the embodiments of the present disclosure will be listed and explained.

(1) The measurement method according to the embodiment of the present disclosure is a measurement method in a tunnel in which a cable is installed, and uses a non-contact method to measure the cable surface temperature, which is the surface temperature of the cable, and the tunnel in the tunnel. and calculating the temperature inside the tunnel, which is the temperature inside the tunnel, by performing a thermal analysis using the measurement results of the cable surface temperature and the wall temperature as boundary conditions. .

In this way, the method of measuring the surface temperature and wall surface temperature using a non-contact method and calculating the air temperature inside the cave through thermal analysis using the measurement results as boundary conditions has improved the measurement equipment compared to the method using the contact method. Since the influence of the installation state on the measurement results can be reduced, accurate surface temperature and wall surface temperature can be easily measured, and the temperature inside the tunnel can be calculated based on the measurement results. Therefore, the temperature inside the tunnel where the cable is installed can be easily measured.

(2) A cooling pipe may further be disposed in the tunnel, and the measuring method further includes the step of measuring a cooling pipe surface temperature, which is a surface temperature of the cooling pipe, using a non-contact method. In the step of calculating the temperature inside the tunnel, the temperature inside the tunnel may be calculated by performing the thermal analysis using the cooling pipe surface temperature as a boundary condition.

With such a method, the air temperature within the tunnel can be measured while also taking into account the surface temperature of the cooling pipe arranged within the tunnel.

(3) In the step of measuring the cable surface temperature and the wall surface temperature, the cable surface temperature and the wall surface temperature may be measured using a thermal camera.

With this method, surface temperature and wall surface temperature at multiple points can be measured with a simple configuration without installing many contact sensors in the tunnel, and based on the measurement results, for example, the temperature can be measured at multiple locations within the tunnel. The temperature inside the cave can be calculated.

(4) The measurement method further includes the measurement method using the thermal camera, which is calculated based on a comparison result between the cable surface temperature measured using the thermal camera and the cable surface temperature measured using a contact method. The step of obtaining a correction parameter for correcting the measurement result of the cable surface temperature may be included, and in the step of calculating the tunnel internal temperature, the cable surface temperature corrected using the correction parameter is set as a boundary condition. The temperature inside the tunnel may be calculated by performing the thermal analysis using

With such a method, the temperature inside the tunnel can be calculated more accurately based on a more accurate measurement result of the surface temperature in which the emissivity of the surface of the cable is taken into consideration.

(5) The measurement method further includes measuring the temperature of the cable based on the cable surface temperature measured using the non-contact method, the temperature inside the tunnel calculated by performing the thermal analysis, and the amount of current flowing through the cable. The method may include a step of calculating a conductor temperature.

With such a method, the conductor temperature can be calculated more accurately than the conventional method of calculating the conductor temperature based on the surface temperature of the cable.

(6) The measurement method further includes the amount of current flowing through the cable, the temperature of the conductor of the cable, the temperature inside the cave, the wind speed inside the tunnel, and the entrance/exit temperature that is the temperature at the entrance/exit of the tunnel. a step of obtaining a learning model generated by machine learning of the relationship between the two, and predicting the conductor temperature and the temperature inside the cave by giving the current amount, the wind speed, and the entrance/exit temperature to the learning model. It may also include a step of.

With such a method, it is possible to determine, for example, the amount of power that can be transmitted using a cable, based on the prediction result.

(7) In the step of calculating the temperature inside the tunnel, a thermal fluid analysis may be performed as the thermal analysis.

With such a method, the temperature inside the tunnel can be calculated more accurately than a method using other methods such as heat transfer analysis as a thermal analysis.

(8) The calculation device according to the embodiment of the present disclosure is a calculation device that calculates the temperature inside the tunnel, which is the temperature inside the tunnel in which the cable is installed, and the calculation device calculates the surface temperature of the cable using a non-contact method. an acquisition unit that acquires a measurement result of the wall surface temperature of the cave; and a calculation unit that calculates the temperature inside the cave by performing a thermal analysis using the measurement result acquired by the acquisition unit as a boundary condition. Be prepared.

In this way, by acquiring the measurement results of the surface temperature and wall surface temperature using the non-contact method, and calculating the temperature inside the cave through thermal analysis using the acquired measurement results as boundary conditions, the surface temperature using the contact method can be calculated. Compared to a configuration that uses temperature and wall surface temperature measurement results, it is possible to reduce the effect that the installation condition of the measuring device has on the measurement results, making it easy to measure accurate surface and wall temperature and to calculate the temperature based on the measurement results. It is possible to calculate the temperature inside the cave. Therefore, the temperature inside the tunnel where the cable is installed can be easily measured.

(9) The calculation program according to the embodiment of the present disclosure is a calculation program used in a calculation device that calculates the temperature inside a tunnel in which a cable is installed, An acquisition unit that acquires the measurement results of the surface temperature of the cable used and the wall temperature of the tunnel, and a thermal analysis using the measurement results acquired by the acquisition unit as boundary conditions, This is a program for functioning as a calculation unit that calculates temperature.

In this way, by acquiring the measurement results of the surface temperature and wall surface temperature using the non-contact method, and calculating the temperature inside the cave through thermal analysis using the acquired measurement results as boundary conditions, the surface temperature using the contact method can be calculated. Compared to a configuration that uses temperature and wall surface temperature measurement results, it is possible to reduce the effect that the installation condition of the measuring device has on the measurement results, making it easy to measure accurate surface and wall temperature and to calculate the temperature based on the measurement results. It is possible to calculate the temperature inside the cave. Therefore, the temperature inside the tunnel where the cable is installed can be easily measured.

Embodiments of the present disclosure will be described below with reference to the drawings. In addition, the same reference numerals are attached to the same or corresponding parts in the drawings, and the description thereof will not be repeated. Furthermore, at least some of the embodiments described below may be combined arbitrarily.

[Configuration and basic operation]
<Measurement system>
FIG. 1 is a diagram showing the configuration of a measurement system according to an embodiment of the present disclosure. FIG. 1 is a top view of the manholes 202A, 202B and the tunnel 201. Referring to FIG. 1, power cables 151A, 151B and cooling pipes 161A, 161B are installed in tunnel 201 between manhole 202A and manhole 202B. More specifically, the power cable 151A and the cooling pipe 161A are installed near one side of the tunnel 201, and the power cable 151B and the cooling pipe 161B are installed near the other side of the tunnel 201. ing. Note that a plurality of power cables 151A and a plurality of power cables 151B may be installed in the tunnel 201. The tunnel 201 has, for example, a cylindrical shape.

The measurement system 301 includes four thermal cameras 21, four thermal cameras 22, four thermal cameras 23, two thermometers 31, two anemometers 41, a transmitter 51, and a calculation device 101. Be prepared. More specifically, the measurement system 301 includes two thermal cameras 21A and two thermal cameras 21B as the thermal cameras 21, and two thermal cameras 22A and two thermal cameras 22B as the thermal cameras 22. 23 includes two thermal cameras 23A and two thermal cameras 23B. Note that the measurement system 301 may include one, two, three, or five or more thermal cameras 21. Furthermore, the measurement system 301 may include one, two, three, or five or more thermal cameras 22. Furthermore, the measurement system 301 may include one, two, three, or five or more thermal cameras 23. Furthermore, the measurement system 301 may be configured to include one or more thermometers 31. Furthermore, the measurement system 301 may be configured to include one or more anemometers 41.

The calculation device 101 is provided on the ground. Thermal cameras 21, 22, 23, thermometer 31, anemometer 41, and transmitter 51 are provided underground. More specifically, the thermal cameras 21B, 22B, and 23B are attached to one side of the tunnel 201. Further, the thermal cameras 21A, 22A, and 23A are attached to the other side of the tunnel 201. The thermometer 31 is attached to the wall of the tunnel 201 at one end and the other end of the tunnel 201. The anemometer 41 is attached to the wall of the tunnel 201 at one end and the other end of the tunnel 201. The transmitting device 51 is provided, for example, in the manhole 202A.

The thermal camera 21 measures the surface temperature Tsf of the power cable 151 in a predetermined measurement area using a non-contact method. The surface temperature Tsf is an example of the cable surface temperature. More specifically, the thermal camera 21A continuously transmits thermographic images indicating the surface temperature Tsf of the power cable 151A to the transmitter 51 via a communication line (not shown). Further, the thermal camera 21B continuously transmits a thermography image indicating the surface temperature Tsf of the power cable 151B to the transmitting device 51 via a communication line (not shown). Note that the measurement system 301 may be configured without the thermal camera 21B when the power cable 151B is not installed in the tunnel 201 and when the surface temperature Tsf of the power cable 151B is not a measurement target. Further, the thermal camera 21 may be attached to the upper surface of the tunnel 201.

The thermal camera 22 measures the wall surface temperature Twl of the tunnel 201 in a predetermined measurement area using a non-contact method. More specifically, the thermal camera 22A continuously transmits a thermography image showing the wall surface temperature Twl on one side of the tunnel 201 to the transmitter 51 via a communication line (not shown). Further, the thermal camera 22B continuously transmits a thermography image showing the wall surface temperature Twl on the other side of the tunnel 201 to the transmitting device 51 via a communication line (not shown). Note that the measurement system 301 may be configured without the thermal camera 22B when the power cable 151B is not installed in the tunnel 201 and when the surface temperature Tsf of the power cable 151B is not a measurement target. Further, the thermal camera 22 may be attached to the upper surface of the tunnel 201.

The thermal camera 23 measures the surface temperature Tsf of the cooling pipe 161 in a predetermined measurement area using a non-contact method. The surface temperature Tcp is an example of the cooling pipe surface temperature. More specifically, the thermal camera 23A continuously transmits thermographic images indicating the surface temperature Tcp of the cooling pipe 161A to the transmitting device 51 via a communication line (not shown). Further, the thermal camera 23B continuously transmits a thermography image indicating the surface temperature Tcp of the cooling pipe 161B to the transmitting device 51 via a communication line (not shown). Note that the measurement system 301 may be configured without the thermal camera 23B when the cooling pipe 161B is not installed in the tunnel 201 and when the surface temperature Tcp of the cooling pipe 161B is not a measurement target. Further, the thermal camera 23 may be attached to the upper surface of the tunnel 201.

The thermometer 31 continuously measures the entrance/exit temperature Tad, which is the temperature at the entrance/exit of the tunnel 201, and transmits the measurement result to the transmitter 51 via a communication line (not shown).

The anemometer 41 continuously measures the wind speed Ws at the entrance and exit of the tunnel 201 and transmits the measurement results to the transmitter 51 via a communication line (not shown).

The transmitting device 51 receives thermography images from the thermal cameras 21, 22, and 23, respectively. The transmitting device 51 also receives the measurement results of the entrance/exit temperature Tad and the wind speed Ws from the thermometer 31 and the anemometer 41, respectively. The transmitting device 51 periodically transmits, at the same time, cable image information including a thermography image indicating the surface temperature Tsf, wall image information including a thermography image indicating the wall temperature Twl, and cable image including the thermography image indicating the surface temperature Tcp. information, a measurement result of the entrance/exit temperature Tad, and a measurement result of the wind speed Ws, and stores the generated tunnel information in the storage unit.

The transmitting device 51 transmits the tunnel information to a relay device installed on the ground by power line communication (PLC) using a power cable 151. The relay device transmits the tunnel information received from the transmitting device 51 to the calculation device 101. Note that the transmitting device 51 may be configured to transmit the tunnel information to the calculation device 101 through wireless communication, or may be configured to transmit the tunnel information to the calculation device 101 via a wired transmission path for communication (not shown). Good too.

The calculation device 101 receives the tunnel information from the transmitting device 51 and performs a thermal analysis using the received tunnel information to calculate the tunnel internal temperature Ts, which is the temperature inside the tunnel 201 .

<Calculation device>
FIG. 2 is a diagram showing the configuration of a calculation device according to an embodiment of the present disclosure. Referring to FIG. 2, calculation device 101 includes a receiving section 11, a model creating section 12, a correcting section 13, a calculating section 14, and a storage section 15. A part or all of the receiving section 11, the model creating section 12, the correcting section 13, and the calculating section 14 are realized by, for example, a processor such as a CPU (Central Processing Unit) and a DSP (Digital Signal Processor). The storage unit 15 is, for example, a nonvolatile memory. The receiving unit 11 is an example of an obtaining unit.

The model creation unit 12 creates a 3D model used for thermal analysis of the tunnel 201.

The receiving unit 11 acquires the measurement results of the surface temperatures Tsf and Tcp and the wall temperature Twl. More specifically, the receiving unit 11 receives the tunnel information from the transmitting device 51. The receiving unit 11 stores the received tunnel information in the storage unit 15.

The correction unit 13 corrects the thermography image included in the tunnel information stored in the storage unit 15 by the reception unit 11.

The calculation unit 14 calculates the tunnel internal temperature Ts by performing thermal analysis using the measurement results of the surface temperatures Tsf, Tcp and wall temperature Twl acquired by the reception unit 11 as boundary conditions. For example, the calculation unit 14 calculates the temperature Ts inside the tunnel by performing a thermo-fluid analysis on the air inside the tunnel 201 using the measurement results of the surface temperatures Tsf, Tcp and the wall temperature Twl as boundary conditions. do.

More specifically, the calculation unit 14 acquires the tunnel information including the thermography image corrected by the correction unit 13 from the storage unit 15, and calculates the measurement by the thermal camera 21 based on the cable image information included in the tunnel information. A surface temperature TAsf, which is an average value of the surface temperatures Tsf in the region, is calculated. Further, the calculation unit 14 calculates the wall temperature TAwl, which is the average value of the wall temperature Twl in the measurement area of the thermal camera 22, based on the wall image information included in the tunnel information. Further, the calculation unit 14 calculates the surface temperature TAcp, which is the average value of the surface temperatures Tcp in the measurement area of the thermal camera 23, based on the cable image information included in the tunnel information.

The calculation unit 14 calculates heat based on the 3D model created by the model creation unit 12 using the entrance/exit air temperature Tad and wind speed Ws indicated by the tunnel information as well as the calculated surface temperatures TAsf, TAcp and wall temperature TAwl as boundary conditions. By performing fluid analysis, the temperature inside the tunnel Ts is calculated.

The details of the processing of each unit in the calculation device 101 will be described below.

(Creation of 3D model)
The model creation unit 12 acquires a plurality of captured images generated by photographing the measurement area of each of the thermal cameras 21 and 22 with an optical camera, and performs photogrammetry using the acquired plurality of captured images. By doing this, 3D data inside the tunnel 201 is created. For example, the model creation unit 12 creates a 3D model that includes information on the measurement regions by associating the measurement regions of the thermal cameras 21 and 22 with 3D data.

Here, the tunnel 201 has the same continuous shape along the longitudinal direction. For example, the model creation unit 12 can create a 3D model of the entire area of the tunnel 201 by connecting 3D models of some areas in the longitudinal direction of the tunnel 201 in the longitudinal direction. The model creation unit 12 stores the created 3D model in the storage unit 15.

Note that the model creation unit 12 acquires cable image information and wall image information generated by the thermal cameras 21, 22, and 23, respectively, and performs photogrammetry using the acquired cable image information and wall image information. It may also be configured to create 3D data. Further, the administrator of the calculation device 101 manually creates a 3D model based on the components such as the power cable 151 in the tunnel 201 using modeling software, and stores the generated 3D model in the storage unit 15. Good too.

(Setting correction values for thermography images)
In the thermal camera 21, the emissivity EM1 of the surface of a typical power cable 151 is set as a design value. Further, the emissivity EM2 of the wall surface of the typical tunnel 201 is set as a design value for the thermal camera 22. The thermal camera 23 is set to have a typical emissivity EM3 of the surface of the cooling pipe 161 as a design value.

For example, the administrator of the calculation device 101 performs a preliminary operation of the measurement system 301 to calibrate the thermal cameras 21, 22, and 23.

More specifically, the administrator measures the surface temperature Tsf at a predetermined measurement position Pm1 on the power cable 151 using, for example, a contact thermometer. The administrator also obtains the surface temperature Tsf of the measurement position Pm1 indicated by the thermography image generated by the thermal camera 21.

The administrator determines the measurement result of the surface temperature Tsf by the thermal camera 21 based on the comparison result between the surface temperature Tsf of the measurement position Pm1 measured using the thermometer and the surface temperature Tsf of the measurement position Pm1 shown by the thermography image. A correction parameter CB1 for correcting is calculated. The correction unit 13 receives the correction parameter CB1 from the administrator, and stores the received correction parameter CB1 in the storage unit 15. Thereby, the calculation device 101 can correct the thermography image generated by the thermal camera 21 using the correction parameter CB1 so that the thermography image matches the measurement result of the surface temperature Tsf using the thermometer. can.

Further, the administrator measures the wall surface temperature Twl at a predetermined measurement position Pm2 on the wall surface of the tunnel 201 using, for example, a contact thermometer. The administrator also obtains the wall surface temperature Twl of the measurement position Pm2 indicated by the thermography image generated by the thermal camera 22.

The administrator determines the measurement result of the wall temperature Twl by the thermal camera 22 based on the comparison result between the wall temperature Twl of the measurement position Pm2 measured using the thermometer and the wall temperature Twl of the measurement position Pm2 shown by the thermography image. A correction parameter CB2 for correcting is calculated. The correction unit 13 receives the correction parameter CB2 from the administrator, and stores the received correction parameter CB2 in the storage unit 15. Thereby, the calculation device 101 can correct the thermography image generated by the thermal camera 22 using the correction parameter CB2 so that the thermography image coincides with the measurement result of the wall surface temperature Twl using the thermometer. can.

The administrator also measures the surface temperature Tcp at a predetermined measurement position Pm3 in the cooling pipe 161 using, for example, a contact thermometer. The administrator also obtains the surface temperature Tcp of the measurement position Pm3 indicated by the thermography image generated by the thermal camera 23.

The administrator determines the measurement result of the surface temperature Tcp by the thermal camera 23 based on the comparison result between the surface temperature Tcp of the measurement position Pm3 measured using the thermometer and the surface temperature Tcp of the measurement position Pm3 shown by the thermography image. A correction parameter CB3 for correcting is calculated. The correction unit 13 receives the correction parameter CB3 from the administrator, and stores the received correction parameter CB3 in the storage unit 15. Thereby, the calculation device 101 can correct the thermography image generated by the thermal camera 23 using the correction parameter CB3 so that the thermography image matches the measurement result of the surface temperature Tcp using the thermometer. can.

For example, the administrator calculates the emissivities EM1, EM2, and EM3 in the plurality of tunnels 201, and creates a database of the emissivities EM1, EM2, and EM3. The storage unit 15 stores the database created by the administrator.

(Operation of measurement system)
The transmitting device 51 transmits the tunnel information to the calculating device 101 at a transmission timing according to a predetermined transmission cycle Ct.

The receiving unit 11 receives the tunnel information from the transmitting device 51 and stores the received tunnel information in the storage unit 15.

The correction unit 13 corrects the thermography image included in the tunnel information each time the reception unit 11 stores the tunnel information in the storage unit 15. More specifically, the correction unit 13 corrects the thermography image generated by the thermal camera 21 using the correction parameter CB1. Further, the correction unit 13 corrects the thermography image generated by the thermal camera 22 using the correction parameter CB2. Further, the correction unit 13 corrects the thermography image generated by the thermal camera 23 using the correction parameter CB3.

After the thermography image is corrected by the correction unit 13, the calculation unit 14 acquires the tunnel information including the corrected thermography image and the 3D model created by the model creation unit 12 from the storage unit 15. The temperature inside the tunnel Ts is calculated by performing a thermal fluid analysis based on the 3D model and using the boundary conditions described above.

FIG. 3 is a diagram illustrating an example of a temperature distribution diagram created by the calculation unit in the calculation device according to the embodiment of the present disclosure. FIG. 3 shows a temperature distribution map Mtd in a longitudinal section of the tunnel 201. The temperature distribution map Mtd shows the temperature distribution at a cut surface when the tunnel 201 is cut along a vertical plane that passes through the center of the tunnel 201 in the width direction and is parallel to the longitudinal direction of the tunnel 201. In FIG. 3, region R1 is a region where the temperature is higher than T3 and lower than T4. Further, region R2 is a region where the temperature is higher than T2 and lower than T3. Further, region R3 is a region where the temperature is higher than T1 and lower than T2. Here, T4, T3, T2 and T1 are assumed to be larger in this order. Referring to FIG. 3, the calculation unit 14 calculates the tunnel internal temperature Ts at a plurality of positions within the tunnel 201, and creates a temperature distribution map Mtd based on the calculation results. The calculation unit 14 performs a process of displaying the created temperature distribution map Mtd on a display unit (not shown). Note that the calculation unit 14 creates a temperature distribution map Mtds that three-dimensionally shows the temperature distribution inside the cave 201 instead of or in addition to the temperature distribution map Mtd, and It may also be configured to perform display processing.

FIG. 4 is a diagram illustrating an example of a temperature graph created by the calculation unit in the calculation device according to the embodiment of the present disclosure. FIG. 4 shows a change in the temperature Ts inside the tunnel at a predetermined position in the cross section of the tunnel 201 when moving from one end of the tunnel 201 to the other end along the longitudinal direction of the tunnel 201. In FIG. 4, the horizontal axis indicates the position in the longitudinal direction of the tunnel 201, and the vertical axis indicates the temperature [degree]. Referring to FIG. 4, the calculation unit 14 creates a temperature graph Gt showing the relationship between the position in the longitudinal direction of the tunnel 201 and the temperature Ts inside the tunnel.

When the temperature Ts inside the cave exceeds a predetermined caution threshold ThA1, the calculation unit 14 notifies the administrator of the fact that the temperature Ts inside the cave has exceeded the caution threshold ThA1 and the location by audio or video. In addition, when the temperature inside the tunnel Ts exceeds a predetermined warning threshold ThA2, the calculation unit 14 notifies the administrator by audio or video of the fact that the temperature Ts inside the tunnel exceeds the warning threshold ThA2 and the location. .

(Calculation of power cable conductor temperature)
For example, the calculation unit 14 further calculates the conductor temperature Tcn of the power cable 151 based on the surface temperature Tsf indicated by the tunnel information, the temperature Ts inside the tunnel calculated by performing thermal analysis, and the amount of current Ac flowing through the current cable 151. calculate. For example, the calculation unit 14 calculates the conductor temperature Tcn based on the surface temperature Tsf, the tunnel internal temperature Ts, and the current amount Ac in accordance with JCS (Japanese Cable Makers' Association Standard) No. 168 defined by the Japan Cable Makers' Association.

More specifically, the model creation unit 12 creates in advance a cable model in which the power cable 151 is modeled using a thermal equivalent circuit, and stores the created cable model in the storage unit 15. The cable model is given in advance the thermal resistance value and heat capacity of the conductor components in the power cable 151, and the heat loss due to the insulator, sheath, etc. in the power cable 151, which are calculated according to JCS No. 168.

The calculation unit 14 acquires the measurement result of the current sensor attached to the power cable 151 via the transmitting device 51. The current sensor is, for example, a CT (Curret Transformer).

The calculation unit 14 calculates the amount of heat Vc of the power cable 151 based on the amount of current Ac indicated by the measurement result of the current sensor and the known AC conductor resistance of the power cable 151. For example, the calculating unit 14 calculates the calorific value Vc on the assumption that the calorific value Vc is constant over the entire area of the power cable 151 within the tunnel 201. Thereby, the amount of calculation in the calculation unit 14 can be reduced.

Then, the calculation unit 14 obtains the conductor temperature Tcn by providing the calculated calorific value Vc, surface temperature Tsf, and tunnel internal temperature Ts to the cable model in the storage unit 15.

When the conductor temperature Tcn exceeds a predetermined caution threshold ThB1, the calculation unit 14 notifies the administrator by audio or video that the conductor temperature Tcn exceeds the caution threshold ThB1. Further, when the conductor temperature Tcn exceeds a predetermined warning threshold ThB2, the calculation unit 14 notifies the administrator by audio or video that the conductor temperature Tcn exceeds the warning threshold ThB2.

Note that the calculation unit 14 may be configured to calculate the conductor temperature Tcn by heat transfer analysis.

More specifically, the model creation unit 12 creates a heat transfer model used for heat transfer analysis of the power cable 151 in advance and stores it in the storage unit 15.

The calculation unit 14 calculates the amount of heat Vc based on the amount of current Ac indicated by the measurement result of the current sensor and the known AC conductor resistance of the power cable 151.

The calculation unit 14 calculates the conductor temperature Tcn by performing a heat transfer analysis based on the heat transfer model in the storage unit 15 using the surface temperature Tsf and the calorific value Vc as boundary conditions.

(Prediction of temperature Ts inside the cave)
The main explanatory variables for the maximum value Tmax of the tunnel internal temperature Ts in the tunnel 201 are the conductor temperature Tcn, the outside temperature, and the wind speed Ws. Here, the conductor temperature Tcn has a predetermined correlation with the amount of current Ac. Therefore, by accumulating time series data of the amount of current Ac, the outside temperature, and the wind speed Ws and creating a learning model, the conductor temperature Tcn and the maximum value Tmax can be predicted.

The calculation unit 14 creates a learning model by performing machine learning on the relationship among the current amount Ac, the conductor temperature Tcn, the maximum value Tmax, the wind speed Ws, and the entrance/exit temperature Tad, and stores the created learning model in the storage unit. Save to 15. The calculation unit 14 calculates the maximum value Tmax every time the tunnel internal temperature Ts and the conductor temperature Tcn are calculated, and stores the learning model in the storage unit 15 based on the calculated maximum value Tmax, the conductor temperature Tcn, and the tunnel information. Update.

The calculation unit 14 periodically or irregularly calculates the amount of current Ac flowing through the current cable 151 at a certain time tx in the future according to the power transmission plan, the wind speed Ws and the entrance/exit temperature Tad at the time tx calculated based on weather information, etc. get. The calculation unit 14 predicts the conductor temperature Tcn and the maximum value Tmax at time tx by giving the acquired current amount Ac, wind speed Ws, and entrance/exit temperature Tad to the learning model in the storage unit 15. Then, the calculation unit 14 notifies the administrator of the prediction results of the conductor temperature Tcn and the maximum value Tmax by audio or video.

Note that the calculation unit 14 may exclude parameters having a small correlation with the conductor temperature Tcn and the maximum value Tmax from among the current amount Ac, the wind speed Ws, and the entrance/exit temperature Tad from the learning data of the learning model.

In addition, instead of using the learning model, the calculation unit 14 further uses the acquired current amount Ac, wind speed Ws, and entrance/exit air temperature Tad as boundary conditions to perform thermal fluid analysis and heat transfer analysis, thereby determining the conductor temperature at time tx. The configuration may be such that Tcn and the tunnel internal temperature Ts are predicted.

[Flow of operation]
Each device in the measurement system according to the embodiment of the present disclosure includes a computer including a memory, and an arithmetic processing unit such as a CPU in the computer stores a program including a part or all of each step in the flowchart below in the memory. Read from and execute. The programs for these multiple devices can be installed from outside. The programs of these plurality of devices are stored in recording media or distributed via communication lines.

FIG. 5 is a flowchart defining an example of an operation procedure when creating a 3D model in the measurement system according to the embodiment of the present disclosure.

Referring to FIG. 5, first, the calculation device 101 creates 3D data inside the tunnel 201 by performing photogrammetry using a plurality of captured images inside the tunnel 201 generated by a camera ( Step S11).

Next, the calculation device 101 creates a 3D model of the tunnel 201 by associating the measurement areas of the thermal cameras 21 and 22 with 3D data (step S12).

Next, the calculation device 101 stores the created 3D model in the storage unit 15 (step S13).

FIG. 6 is a flowchart defining an example of an operation procedure when setting correction parameters in the measurement system according to the embodiment of the present disclosure.

Referring to FIG. 6, first, the measurement system 301 calculates the temperature based on the comparison result between the surface temperature Tsf of the measurement position Pm1 measured using a thermometer and the surface temperature Tsf of the measurement position Pm1 shown by the thermography image. A correction parameter CB1 for correcting the measured result of the surface temperature Tsf by the thermal camera 21 is received from the administrator (step S21).

Next, the measurement system 301 stores the received correction parameter CB1 in the storage unit 15 (step S22).

Next, the measurement system 301 calculates the temperature Twl of the thermal camera 22 calculated based on the comparison result between the wall temperature Twl of the measurement position Pm2 measured using the thermometer and the wall temperature Twl of the measurement position Pm2 indicated by the thermography image. A correction parameter CB2 for correcting the measurement result of the wall surface temperature Twl is received from the administrator (step S23).

Next, the measurement system 301 stores the received correction parameter CB2 in the storage unit 15 (step S24).

Next, the measurement system 301 uses the thermal camera 23 which is calculated based on the comparison result between the surface temperature Tcp of the measurement position Pm3 measured using the thermometer and the surface temperature Tcp of the measurement position Pm3 shown by the thermography image. A correction parameter CB3 for correcting the measurement result of the surface temperature Tcp is received from the administrator (step S25).

Next, the measurement system 301 stores the received correction parameter CB3 in the storage unit 15 (step S26).

FIG. 7 is a flowchart illustrating an example of an operation procedure when calculating the temperature inside the cave and the conductor temperature in the measurement system according to the embodiment of the present disclosure.

Referring to FIG. 7, first, thermal cameras 21, 22, and 23 measure surface temperatures Tsf, Tcp and wall temperature Twl (step S31).

Next, the calculation device 101 receives the tunnel information from the transmitting device 51, and corrects the thermography image included in the received tunnel information using the correction parameters CB1, CB2, and CB3. More specifically, the calculation device 101 corrects the thermography images generated by the thermal cameras 21, 22, and 23, respectively, using correction parameters CB1, CB2, and CB3 (step S32).

Next, the calculation device 101 receives the tunnel information from the transmitting device 51, and calculates the temperature Ts inside the tunnel by performing a thermal fluid analysis using the boundary conditions based on the received tunnel information based on the 3D model. (Step S33).

Next, the calculation device 101 creates a temperature distribution map Mtd showing the temperature distribution within the tunnel 201, and performs a process of displaying the created temperature distribution map Mtd on a display section (not shown) (step S34).

Next, the calculation device 101 calculates the conductor temperature Tcn based on the surface temperature Tsf indicated by the tunnel information, the calculated tunnel internal temperature Ts, and the current amount Ac, in accordance with JCS No. 168 specified by the Japan Electric Cable Manufacturers Association (step S35 ).

Next, the calculation device 101 performs a notification process of notifying the administrator by audio or video when the tunnel internal temperature Ts exceeds the caution threshold ThA1 or the warning threshold ThA2. Further, when the conductor temperature Tcn exceeds the caution threshold ThB1 or the warning threshold ThB2, the calculation device 101 performs a notification process of notifying the administrator by audio or video (step S36).

FIG. 8 is a flowchart that defines an example of an operation procedure when predicting the temperature inside a cave and the conductor temperature in the measurement system according to the embodiment of the present disclosure.

Referring to FIG. 8, calculation device 101 first creates a learning model by performing machine learning on the relationship among current amount Ac, conductor temperature Tcn, maximum value Tmax, wind speed Ws, and entrance/exit temperature Tad. (Step S41).

Next, the calculation device 101 obtains the amount of current Ac flowing through the current cable 151 at time tx, the wind speed Ws and the entrance/exit temperature Tad at time tx calculated based on weather information, etc. according to the power transmission plan (step S42).

Next, the calculation device 101 predicts the conductor temperature Tcn and the maximum value Tmax at time tx by giving the acquired current amount Ac, wind speed Ws, and entrance/exit air temperature Tad to the learning model (step S43).

Next, the calculation device 101 performs a notification process of notifying the administrator of the prediction results of the conductor temperature Tcn and the maximum value Tmax by audio or video (step S44).

Next, the calculation device 101 updates the learning model based on the prediction results of the conductor temperature Tcn and maximum value Tmax at time tx and the measurement results of the conductor temperature Tcn and maximum value Tmax at time tx (step S45).

Next, the calculation device 101 repeats the processing from step S42 to step S45 according to the power transmission plan.

Note that although the measurement system 301 according to the embodiment of the present disclosure has a configuration including the thermal cameras 21, 22, and 23, the present disclosure is not limited to this. The measurement system 301 includes, instead of the thermal cameras 21, 22, and 23, other devices that measure the surface temperature Tsf using a non-contact method, other devices that measure the surface temperature Tcp using a non-contact method, and other devices that measure the surface temperature Tcp using a non-contact method. The configuration may include another device that measures the wall surface temperature Twl using a contact method.

Furthermore, the measurement system 301 according to the embodiment of the present disclosure is also applicable to the tunnel 201 in which the cooling pipe 161 is not installed. That is, the calculation device 101 may be configured to calculate the temperature inside the tunnel 201 in which the cooling pipe 161 is not installed. In this case, the measurement system 301 may be configured without the thermal camera 23.

Further, although the calculation device 101 according to the embodiment of the present disclosure has a configuration including the correction unit 13, the configuration is not limited to this. The calculation device 101 may have a configuration that does not include the correction unit 13. In this case, the calculation unit 14 acquires the uncorrected tunnel information and 3D model from the storage unit 15, and performs a thermal fluid analysis using the boundary conditions described above based on the acquired 3D model. Calculate the prefecture temperature Ts.

Further, in the calculation device 101 according to the embodiment of the present disclosure, the correction unit 13 is configured to correct the thermography images respectively generated by the thermal cameras 21, 22, and 23 using the correction parameters CB1, CB2, and CB3. However, it is not limited to this. The thermal camera 21 may measure the temperature of multiple objects. For example, the thermal camera 21 generates a thermography image showing the measurement results of the surface temperatures Tsf, Tcp and the wall temperature Twl, and transmits it to the transmitting device 51. That is, the thermal camera 21 generates a thermography image including the power cable 151, the wall of the tunnel 201, and the cooling pipe 161, and transmits it to the transmitting device 51. In this case, the correction unit 13 identifies the target object included in the thermography image, and corrects the temperature of the target object for each target object using correction parameters CB1, CB2, and CB3. In this case, the calculation unit 14 obtains the surface temperatures Tsf, Tcp and the wall surface temperature Twl by identifying the object included in the thermography image corrected by the correction unit 13, and obtains the surface temperatures Tsf, Tcp and the wall surface temperature Twl. A thermal analysis is performed using the temperature Twl as a boundary condition.

Further, in the calculation device 101 according to the embodiment of the present disclosure, the calculation unit 14 is configured to calculate the tunnel internal temperature Ts and the conductor temperature Tcn, but the calculation unit 14 is not limited to this. The calculation unit 14 may be configured to calculate the tunnel internal temperature Ts but not calculate the conductor temperature Tcn.

Further, in the calculation device 101 according to the embodiment of the present disclosure, the calculation unit 14 is configured to predict the conductor temperature Tcn and the maximum value Tmax at a certain time tx in the future, but the invention is not limited to this. . The calculation unit 14 may be configured not to predict the conductor temperature Tcn and the maximum value Tmax.

Further, in the calculation device 101 according to the embodiment of the present disclosure, the calculation unit 14 is configured to acquire the measurement result of the current sensor attached to the power cable 151, but the calculation unit 14 is not limited to this. The calculation unit 14 may be configured to acquire current information indicating the amount of current Ac from a system external to the measurement system 301 instead of acquiring the measurement results of the current sensor, or may be configured to receive current information from an administrator. It may be.

Further, in the calculation device 101 according to the embodiment of the present disclosure, the calculation unit 14 is configured to calculate the temperature Ts inside the tunnel by performing a thermal fluid analysis on the air inside the tunnel 201. , but is not limited to this. The calculation unit 14 may be configured to calculate the tunnel internal temperature Ts by performing thermal analysis other than thermal fluid analysis, such as heat transfer analysis.

By the way, there is a need for a technology that can easily measure the temperature inside a tunnel in which a cable is installed.

More specifically, for example, the power cable 151 for power transmission generates heat due to the flow of current, and as the power cable 151 generates heat, the temperature within the tunnel 201 also rises. It is necessary to transmit power using the power cable 151 so that the temperature of the tunnel 201 is below a predetermined value.

Further, in the techniques described in Patent Documents 1 and 2, it is necessary to install a large number of contact-type thermometers underground. In addition, in the method of calculating the cable conductor temperature based on the surface temperature of the cable and in accordance with JCS No. 168 specified by the Japan Cable Manufacturers Association, as in the techniques described in Patent Documents 1 and 2, it is difficult to accurately calculate the conductor temperature. may not be possible.

In contrast, the measurement method according to the embodiment of the present disclosure is a measurement method within the tunnel 201 in which the power cable 151 is installed. In this measurement method, first, the surface temperature Tsf of the power cable 151 and the wall temperature Twl of the tunnel 201 are measured using a non-contact method. Next, a thermal analysis is performed using the measurement results of the surface temperature Tsf and the wall surface temperature Twl as boundary conditions to calculate the tunnel internal temperature Ts, which is the temperature inside the tunnel 201.

In this way, the method of measuring the surface temperature Tsf and the wall temperature Twl using a non-contact method and calculating the internal temperature Ts of the tunnel through thermal analysis using the measurement results as boundary conditions is compared to the method using a contact method. Since it is possible to reduce the influence of the installation state of the measuring device on the measurement results, it is possible to accurately measure the surface temperature Tsf and the wall surface temperature Twl, and calculate the tunnel internal temperature Ts based on the measurement results. Therefore, the temperature inside the tunnel 201 where the power cable 151 is installed can be easily measured.

The above embodiments should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

The above description includes the features noted below.
[Additional note 1]
A method for measuring inside a tunnel in which a cable is installed,
using a non-contact method to measure the cable surface temperature, which is the surface temperature of the cable, and the wall temperature of the tunnel;
calculating the temperature inside the tunnel, which is the temperature inside the tunnel, by performing a thermal analysis using the measurement results of the cable surface temperature and the wall surface temperature as boundary conditions;
In the step of calculating the temperature inside the cave, which is the temperature inside the cave, thermal analysis is performed using the average value of the surface temperature in the predetermined measurement area and the average value of the wall surface temperature in the predetermined measurement area as boundary conditions. How to measure.

11 Receiving unit 12 Model creation unit 13 Correction unit 14 Calculating unit 15 Storage unit 21, 22 Thermal camera 31 Thermometer 41 Anemometer 51 Transmitting device 101 Calculating device 151 Power cable 201 Tunnel 202A, 202B Manhole 301 Measurement system Mtd Temperature distribution map Gt temperature graph R1, R2, R3 area

Claims (9)

A method for measuring inside a tunnel in which a cable is installed,
using a non-contact method to measure the cable surface temperature, which is the surface temperature of the cable, and the wall temperature of the tunnel;
A measuring method comprising the step of calculating an internal temperature of the tunnel, which is an air temperature within the tunnel, by performing a thermal analysis using the measurement results of the cable surface temperature and the wall surface temperature as boundary conditions. A cooling pipe is further arranged in the tunnel,
The measurement method further includes:
A step of measuring a cooling pipe surface temperature, which is a surface temperature of the cooling pipe, using a non-contact method,
2. The measuring method according to claim 1, wherein in the step of calculating the temperature inside the tunnel, the temperature inside the tunnel is calculated by performing the thermal analysis using the cooling pipe surface temperature as a boundary condition. 3. The measuring method according to claim 1, wherein in the step of measuring the cable surface temperature and the wall surface temperature, the cable surface temperature and the wall surface temperature are measured using a thermal camera. The measurement method further includes:
Correcting the measurement result of the cable surface temperature by the thermal camera, which is calculated based on a comparison result between the cable surface temperature measured using the thermal camera and the cable surface temperature measured using a contact method. obtaining correction parameters for;
According to claim 3, in the step of calculating the temperature inside the tunnel, the temperature inside the tunnel is calculated by performing the thermal analysis using the cable surface temperature corrected using the correction parameter as a boundary condition. How to measure. The measurement method further includes:
Calculating the temperature of the conductor of the cable based on the cable surface temperature measured using the non-contact method, the temperature inside the tunnel calculated by performing the thermal analysis, and the amount of current flowing through the cable, The measuring method according to any one of claims 1 to 4. The measurement method further includes:
Generated by machine learning of the relationship between the amount of current flowing through the cable, the conductor temperature of the cable, the temperature inside the cave, the wind speed inside the tunnel, and the entrance temperature that is the temperature at the entrance and exit of the tunnel. a step of obtaining a trained learning model;
6. The method according to claim 1, further comprising the step of predicting the conductor temperature and the tunnel temperature by giving the current amount, the wind speed, and the entrance/exit temperature to the learning model. How to measure. The measuring method according to any one of claims 1 to 6, wherein in the step of calculating the temperature inside the cave, a thermal fluid analysis is performed as the thermal analysis. A calculation device that calculates the temperature inside a tunnel, which is the temperature inside a tunnel in which a cable is installed,
an acquisition unit that acquires measurement results of the surface temperature of the cable and the wall surface temperature of the tunnel using a non-contact method;
A calculation device comprising: a calculation unit that calculates the temperature inside the tunnel by performing a thermal analysis using the measurement results acquired by the acquisition unit as a boundary condition. A calculation program used in a calculation device that calculates the temperature inside a tunnel, which is the temperature inside a tunnel in which a cable is installed,
computer,
an acquisition unit that acquires measurement results of the surface temperature of the cable and the wall surface temperature of the tunnel using a non-contact method;
a calculation unit that calculates the temperature inside the tunnel by performing a thermal analysis using the measurement results acquired by the acquisition unit as a boundary condition;
A calculation program to function as a.

Images