JP5946993B2 - Liquid oil leak detection device - Google Patents

Description

The present invention relates to liquids leak detection system that detect by irradiating the insulating oil leaked laser beam into the examination region of the insulating oil leakage, in particular, use of the infrared absorption principle of insulating oil middle infrared region with respect to the laser beam It relates liquids leak detection system that detect the insulating oil leakage by.

  As an example in which liquid leakage becomes a problem, for example, there is leakage of insulating oil from an insulating oil filling facility such as a transformer (transformer) in a power plant or substation. Such insulation oil filling equipment is based on a design that does not leak oil, but insulation oil may leak due to long-term use, disasters such as earthquakes, and the like. Recently, insulating oil that does not use PCB is used, but old equipment and appliances may use insulating oil containing PCB, or recycled oil containing PCB may be used. The influence of the above may not only cause a malfunction or failure of the original function of equipment / equipment, but may also have an adverse effect on the environment. For this reason, electric power companies are required to make regular patrols, and if oil leaks are found, repair oil leaks, replace equipment, replace soil, and report to the supervisory authorities.

  By the way, conventionally, as an oil leakage detection device that detects oil using laser light, for example, there is one described in Patent Document 1. The purpose of this device is to prevent a large amount of oil from flowing out of the ocean from oil carriers, etc., and to irradiate the surface of the sea and seawater with laser light, and to emit fluorescence and scattered light from the oil leaked by the laser light irradiation. By detecting it, oil leakage floating in the sea surface or sea water is detected.

JP 2000-275135 A

  However, the oil leakage detection device described in Patent Document 1 is intended for detection of oil components floating on the sea surface, and uses fluorescence and scattered light for oil leakage detection. In consideration of the above, the wavelength of the laser beam to be irradiated is 220 to 550 nm, and the light receiving wavelength is 350 to 570 nm. In this case, considering that the maximum value of the solar radiation spectrum is around 550 nm, there is a problem that it is difficult to detect oil leakage under daylight sunlight and cannot be used for daytime oil leakage inspection. In electric power companies, the current periodic patrols are conducted by inspection of the oil leakage by the patrolman, and the presence or absence of oil leakage is determined by the patrolman's subjective judgment. There is a problem that is extremely difficult. For this reason, from the viewpoint of improving the reliability of leakage inspection, safety measures, etc., there is a demand for an oil leakage detection device that can objectively determine the presence or absence of oil leakage and can detect even a very small amount of oil leakage.

The present invention has been made in view of the above problems, and an object thereof is to provide a liquid body leak detection system that can objectively detect an insulating oil leakage to day or night.

The liquid leakage detection apparatus of the present invention comprises a laser emitting means for generating a laser beam having a wavelength band centered on 3.6 μm as a wavelength in the mid-infrared region irradiated to an inspection region for insulating oil leakage, Wavelength sweep control means for sweeping and controlling the wavelength including the light absorption wavelength band of the insulating oil to be inspected, and light receiving means for receiving the reflected light of the laser light from the inspection area and generating an output corresponding to the received light intensity a warning means for warning the leak detection means for detecting the detection to the insulating oil leaking drop in output of the light receiving means, said insulating oil leakage is detected to the operator, the inspection of the insulating oil leaks A position information acquisition means for acquiring position information of a place , wherein the leakage detection means is a ratio of a maximum received light intensity when swept including the light absorption wavelength band of the insulating oil and the amount of the drop Is used as a judgment value. Wherein the determining whether or the set threshold value.

In such a configuration, a laser beam having a wavelength band having a central wavelength of 3.6 μm is generated as a wavelength in the mid-infrared region irradiated from the laser light emitting unit to the insulating oil leakage inspection region, and the wavelength sweep control unit generates the wavelength of the laser beam. Is swept to include the light absorption wavelength band of the insulating oil to be inspected and irradiated to the inspection area for insulating oil leakage. The light receiving means receives the reflected light of the laser light from the inspection region and generates an output corresponding to the received light intensity, and the leak detection means detects a drop in the output of the light receiving means. Specifically, the leakage detection means determines whether or not the ratio is equal to or greater than a preset threshold value with a ratio between the maximum light receiving intensity and the amount of depression when swept including the light absorption wavelength band of the insulating oil as a determination value. judge. If there is a drop in the output of the light receiving means, it is determined that there is light absorption by the insulating oil, thereby detecting leakage of the insulating oil. Further, the warning means warns the operator that the leakage of the insulating oil has been detected. Further, the position information acquisition means acquires the position information of the inspection location for the insulating oil leakage.

According to the liquid leak detection apparatus of the present invention, since the laser light having a wavelength band having a central wavelength of 3.6 μm is used as the wavelength in the mid-infrared region not affected by sunlight, the insulating oil can be used regardless of day or night. Leakage inspection can be performed. In addition, a small amount of insulation can be obtained by determining whether or not the ratio is equal to or greater than a preset threshold with the ratio between the maximum received light intensity and the amount of drop when swept including the light absorption wavelength band of the insulating oil as a determination value. Oil leaks can be detected reliably, and the reliability of insulation oil leak inspection can be increased. In addition, it is possible to quickly and objectively find leaked insulation oil filling equipment and to identify the installation location of the insulation oil filling equipment, so that safety measures such as repair and replacement of the insulation oil filling equipment can be performed without delay. . Further, the warning means can warn the operator that the leakage of insulating oil has been detected.

It is explanatory drawing which shows an example of the leak detection of the insulating oil by the liquid leak detection apparatus of this invention. It is a figure which shows the difference in the received light intensity by the presence or absence of the leak when a laser beam is swept. It is a figure which shows the transmission spectrum of insulating oil. It is a figure which shows the radiation spectrum of sunlight and air | atmosphere. It is a figure which shows the transmission spectrum of water and water vapor | steam. It is a figure which shows the table | surface which illustrated the liquid (oil content and liquid other than oil content) in which leak detection is possible with the liquid leak detection apparatus of this invention. It is a block diagram which shows the structure of one Embodiment of the liquid leak detection apparatus of this invention. It is a figure which shows the structural example of the coaxial optical system applied by embodiment same as the above. It is a figure explaining the difference of a coaxial optical system and a biaxial optical system. It is a flowchart explaining operation | movement of the liquid leak detection apparatus of this embodiment. It is a flowchart explaining the specific operation | movement of the oil leak detection operation | movement of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Insulating oil leakage detection by the liquid leakage detection apparatus of the present invention irradiates a laser beam having a wavelength in the mid-infrared region (2 to 25 μm) to the inspection region for inspecting the leakage of the insulating oil , and determines the wavelength of the laser light to be inspected. by sweeping comprises a light absorption wavelength band of the insulating oil receiving light reflected from the inspection area, by detecting a drop in the light receiving intensity of the reflected light by the infrared absorption of the insulating oil, it detects the insulating oil leakage It is characterized by doing.

For leak detection of insulating oil due to liquid leak detection system of the present invention, as an example insulating oil sealed in the transformer (transformer) In example embodiment, an example of a case of detecting the leakage, with reference to FIG. 1 explained To do.

The received light intensity I in the liquid leak detection device 1 is the emission intensity I ₀ corresponding to the wavelength λ of the laser light, the reciprocation ρ ² of attenuation in the laser light irradiation space from the liquid leak detection device 1 to the surface of the oil sealing equipment ² , the oil content The following equation (1) is defined by the product of the coating film reflectance R on the surface of the sealing equipment 2, the reciprocal T ² of the oil leakage transmission rate, and the efficiency f in the liquid leakage detection device known 1. Since I, I ₀ , ρ ² , R, T ² and f depend on the wavelength of the laser beam, the following equation (1) is expressed as a function of the wavelength.
I (λ) = I ₀ (λ) · ρ (λ) ² · T (λ) ² · R (λ) · f (λ) (1)

Here, the emission intensity I ₀ of the laser beam is known by measuring in real time with an oscillation monitor in the liquid leak detection apparatus 1, and the attenuation ρ in the laser beam irradiation space is used to make the laser beam a parallel beam with no beam spread. Can be ignored (ρ≈1), and the coating film reflectance R can be regarded as a constant value regardless of the inspection location if the significant dirt on the surface of the oil-sealing facility 2 is ignored. The efficiency f can be made constant by measuring the design value and the liquid leakage detection device 1 during inspection, so the only variable in the oil leakage inspection is the oil leakage transmittance T. And when there is no oil leakage, T = 1, but when there is oil leakage, the specific wavelength based on the light absorption property of the oil depending on the light absorption property of the oil to be inspected and the oil leakage film thickness. Since T <1 in the band and the light reception intensity I decreases, the presence or absence of oil leakage can be detected by measuring the light reception intensity I.

Specifically, by sweeping the current applied to the laser oscillator, the emission intensity I ₀ and the wavelength of the laser beam are simultaneously swept as indicated by the dotted line in FIG. The light reception intensity I is measured with a value corresponding to the emission intensity I ₀ as shown by the solid line in FIG. 2 when there is no oil leakage. When there is oil leakage, the light reception intensity I is a transmittance T in the light absorption wavelength band of insulating oil. The corresponding light absorption occurs, the received light intensity I decreases, and a drop occurs as shown by the alternate long and short dash line in FIG. Therefore, by sweeping the wavelength of the laser light including the light absorption wavelength band of the insulating oil, it is possible to detect the presence or absence of oil leakage by detecting a drop in the received light intensity I occurring in the light absorption wavelength band of the insulating oil. . FIG. 2 schematically shows the state of the emission intensity I ₀ and the received light intensity I depending on the presence or absence of oil leakage during the wavelength sweep. Here, the drop is a strong light absorption portion in a predetermined wavelength region as shown in FIG.

  In the case of insulating oil, light absorption is shown in the optical wavelength band of 3.4 to 3.7 μm from the transmission spectrum shown in FIG. 3, and thus the received light intensity I is in the range of the wavelength of the emitted laser light of 3.4 to 3.7 μm. Will be depressed.

  Moreover, as shown in FIG. 4, the radiation spectrum of sunlight (short wave radiation) has wavelengths in the ultraviolet region (wavelength 280 to 380 nm), visible light region (wavelength 380 to 750 nm), and near infrared region (wavelength 700 to 2500 nm). It shows strong spectral irradiance in the region, and is particularly strong in the visible light region. For this reason, in the liquid leakage detection apparatus using light in the ultraviolet region (wavelength 280 to 380 nm), visible light region (wavelength 380 to 750 nm), and near infrared region (wavelength 700 to 2500 nm) as in the past, the influence of sunlight The daytime oil leak test was difficult.

On the other hand, in the present invention, laser light having a wavelength in the mid-infrared region (2 to 25 μm) having almost no spectral irradiance of sunlight (short wave radiation) is used (in the case of insulating oil, the central wavelength is 3.6 μm). Therefore, oil leakage inspection is possible without being affected by sunlight (short wave radiation) not only at night but also in the daytime when sunlight is present. Further, as shown in FIG. 4, in the wavelength band of 3.6 μm, the spectral irradiance of atmospheric radiation (long wave radiation) from surface materials and clouds is also 0 compared to 1.2 W / m ² · nm ⁻¹ in fine weather. .001 W / m ² · nm ⁻¹ , which is 1/1000 or less, so if laser light having a wavelength band centered on 3.6 μm is used as in the case of oil leakage inspection according to the present invention, It is hard to be affected.

  The oil-filled equipment installed on the ground often gets wet with raindrops, and in consideration of the effects of water vapor in the atmosphere on oil leakage inspection, the wavelength range is less affected by moisture in the liquid state or gas state (water vapor) The use of the laser beam, that is, the laser beam having a wavelength range with a high moisture transmittance improves the S / N ratio at the time of measurement. As shown in FIG. 5, the transmission spectrum of water (liquid) and water vapor has a light transmittance of approximately 100% and no light absorption in the wavelength region of 3.6 μm. If laser light having a wavelength band of 3.6 μm is used in the oil leakage inspection, there is no influence on the oil leakage inspection due to water vapor in the atmosphere. As for the influence of water (liquid), since the change in transmittance is gentle in the wavelength range of 3.6 μm, the change in the received light intensity I due to water (liquid) and the insulating oil in the wavelength sweep range. It can be distinguished from the change in the light receiving intensity I due to the insulating oil that changes sharply at the light absorption wavelength, and even if water (liquid) is present, it does not affect the oil leakage inspection.

Moreover, in this invention apparatus , the transmittance | permeability T of oil can be measured by measuring the light reception intensity | strength I from (1) Formula mentioned above. Here, according to Lambert-Beer's law, the transmittance T can be expressed as the following equation (2).
T = exp (−acL) (2)
Where a is the molar extinction coefficient of oil, c is the molar concentration of oil, and L is the path length of the oil through which light passes. Here, since the inspection target is a liquid and adheres to the surface of the oil-filling facility 1, the concentration of oil leakage can be regarded as uniform. Therefore, if the molar extinction coefficient a of the oil to be inspected, the atmospheric pressure, and the molar concentration c in a normal temperature environment are known, the path length L can be obtained from the following equation (3).
L = −ln (T) / ac (3)

  Here, since the path length L is the length of the oil leak through which light has passed, the film thickness of the oil leak can be obtained from the obtained path length L. Since the path length L is the length of light traveling back and forth within the oil leakage, half of the path length L (L / 2) is obtained as the film thickness of the oil leakage. If the liquid to be inspected is, for example, a liquid that has a large viscosity and is difficult to flow, it is considered that the film thickness will increase when there is a large amount of oil leakage, so it is possible to determine the approximate level of oil leakage from the film thickness. .

As described above, according to the liquid leakage detection device of the present invention, it is possible to reliably detect even a small amount of oil leakage that could be overlooked by the visual inspection of a patrolman. In addition, when oil leakage is detected, repair, replacement, soil replacement processing, and transition to reporting to the supervisory authorities can be made in a shorter period of time. Find and deal quickly without delay. Therefore, it is extremely effective for safety measures. In addition, by using laser light having a wavelength in the mid-infrared region, there is an advantage that oil leakage inspection can be performed even in the daytime when there is sunlight, compared to a conventional device that is easily affected by sunlight.

As described above, the leak detection by the liquid leak detection device of the present invention has been described by taking the leak inspection of the insulating oil as an example. However, the liquid leak detection device of the present invention is not limited to various other oils and liquids other than oil as shown in FIG. It can also be applied to leak inspection.

Next, the above-described liquid leakage detection apparatus of the present invention will be specifically described.
FIG. 7 is a block diagram showing a configuration of an embodiment of the liquid leakage detection apparatus of the present invention.
In FIG. 7, the liquid leakage detection device 10 of the present embodiment includes a laser oscillator 11, a coaxial optical system 12, a scan mirror 13, a light receiving unit 14, an oscillation monitor 15, an imaging device 16, and a control unit 17. , A display unit 18, a recording unit 19, a GPS receiver 20, an external interface 21, a measurement switch 22, a battery 23, a warning device 24, and an instruction laser 25.

  The laser oscillator 11 which is a laser emitting unit is driven by the control unit 17 when the measurement switch 22 is turned on and emits laser light in the mid-infrared region. For example, wavelength conversion based on a difference frequency oscillation principle using a nonlinear optical effect is performed. It is a laser oscillator. The laser oscillator 11 only needs to be capable of emitting laser light in the mid-infrared region. For example, a wavelength conversion laser oscillator based on a principle such as sum frequency oscillation, double wave oscillation, parametric oscillation using the nonlinear optical effect, A quantum cascade laser oscillator or the like may be used.

  The coaxial optical system 12 guides the laser light emitted from the laser oscillator 11 to the scan mirror 13 and guides the reflected light incident on the scan mirror 13 coaxially with the emitted laser light to the light receiving unit 14 serving as a light receiving means. For example, a configuration using a half mirror as the beam splitter 31 as shown in FIG. 8A or a configuration using a perforated mirror 32 as shown in FIG. 8B can be adopted.

  A biaxial optical system in which the optical axes of the outgoing light and the reflected light are different may be adopted as the optical system. However, in the case of the biaxial optical system, the outgoing light from the liquid leak detection device 10 is received as shown in FIG. In the short-distance area until it reaches the field of view (shaded area in the figure), almost no reflected light can be received, and there is an unmeasurable area. For this reason, when the biaxial optical system is employed, if the target facility for leak inspection is too close, the reflected light from the surface of the target facility for inspection may not be received and the leak inspection may not be performed. On the other hand, in the case of a coaxial optical system, as is apparent from FIG. 9, there is no non-measurable region as in the biaxial optical system, and the coaxial optical system is relatively compact compared to the biaxial optical system. There are advantages that can be made. Therefore, it is desirable to employ a coaxial optical system.

  The scan mirror 13 scans the laser beam from the laser oscillator 11 two-dimensionally and projects it to the outside of the apparatus 10, and reflects the reflected light from the surface of the oil encapsulating equipment 2 to the light receiving unit 14 via the coaxial optical system 12. This corresponds to a light scanning means for guiding the light, and is constituted by an electromagnetically driven two-dimensional planar galvanometer mirror using a semiconductor manufacturing technique described in Japanese Patent No. 2722314 for performing two-dimensional scanning of light. The details of the electromagnetically driven two-dimensional planar galvanometer mirror are described in Japanese Patent No. 2722314. Briefly, two pairs of torsion bars whose axial directions are orthogonal to each other and swingable by the respective torsion bars The inner and outer movable parts pivotally supported by the semiconductor substrate are integrally formed of a semiconductor substrate, each of the movable parts is provided with a drive coil and a static magnetic field generating means for applying a static magnetic field to the drive coil is provided, and a mirror is provided on the inner movable part. Provided and configured. Then, for example, an electromagnetic driving force is generated by the interaction between a magnetic field generated by supplying an alternating current as a driving current to the driving coil and a static magnetic field, and the movable part is swung. If the frequency of the drive AC current is set to the resonance frequency of the galvanometer mirror, the movable part can be driven to swing efficiently.

  The light receiving unit 14 sends an output corresponding to the received light intensity I of the reflected light received from the scan mirror 13 via the coaxial optical system 12 to the control unit 17.

The oscillation monitor 15 measures the emission intensity I ₀ of the laser beam emitted from the laser oscillator 11 in real time and transmits it to the control unit 17.

  The imaging device 16 captures an image of an inspection area irradiated with laser light. For example, each time the entire inspection area is scanned with laser light, a still image of the inspection area is captured and the image data is controlled by the control unit 17. Send to.

The controller 17 sweeps and controls the wavelength of the emitted laser light by sweeping the applied current to the laser oscillator 11 by turning on the measurement switch 22. Further, as described in the above-described detection of insulating oil leakage , the presence / absence of a drop in the received light output from the light receiving unit 14 is detected to determine the presence / absence of leakage of the insulating oil . Further, when the leakage of the insulating oil is detected, the imaging device 16 is based on position information from the scan mirror 13 (oscillation angle information of the inner and outer movable parts) when the leakage spot is irradiated with laser light. The image data is created by adding information such as coloring instructions and highlight instructions to the corresponding locations on the still image captured in step 1 and the location information of the location of the insulation oil leakage inspection acquired by the GPS receiver 20 as the location information acquisition means. The data is recorded in the recording unit 19 which is a data recording means. Here, the control unit 17 includes functions of a wavelength sweep control unit, a leakage detection unit, and an image processing unit.

  The display unit 18 as display means reads out the still image data recorded from the recording unit 19 and displays it.

  The external interface 21 communicates data recorded in the recording unit 19 with an external device.

  The battery 23 is a power source for driving the liquid leak detection apparatus 10 and supplies power to each part in the liquid leak detection apparatus 10 by turning on a power switch (not shown). As described above, if the battery can be driven, the portable phone can be used even in a place without a power source.

Warning device 24, an insulating oil leakage is detected which corresponds to the warning means to warn the operator of a liquid leak detection system 10, when the control unit 17 determines that there leakage of insulating oil, the control Driven by the output from the unit 17. The warning device 24 may be a device that warns by voice, may use a light such as a lamp, or may use a vibration to warn.

The instruction laser 25 emits a visible light laser for directly indicating the contour of the insulating oil leakage portion and the inspection region. When the leakage of the insulating oil is detected, the instruction laser 25 is driven by the control unit 17 to detect the leakage portion. The laser beam is irradiated from the coaxial optical system via the scan mirror 13. Further, based on position information from the scan mirror 13 (information about the swing angle of each of the inner and outer movable parts), the scan mirror 13 has a contour position of the inspection region (maximum swing angle position of each of the inner and outer movable parts). When it is directed to the position, it is driven by the controller 17 to irradiate a visible light laser.

Next, the operation for inspecting leakage of insulating oil by the liquid leakage detection device of the present embodiment will be described with reference to the flowcharts of FIGS.
FIG. 10 is a flowchart showing the operation when the apparatus power supply is turned on, and FIG. 11 is a flowchart showing the oil leakage detection operation in the flowchart of FIG.

  In FIG. 10, when a power switch (not shown) is turned on to turn on the power, the battery 23 supplies power to each unit, and the control unit 17, the imaging device 16, the display unit 18, and the GPS receiver 20 start operating. Then, the oil leakage inspection by the liquid leakage detection device 10 is possible.

  As a result, in step 1 (indicated by S1 in the figure, the same shall apply hereinafter), the screen of the examination region imaged by the imaging device 16 is displayed on the display unit 18 as a standby screen. On this standby screen, for example, the position information of the liquid leak detection device 10 (inspection location) acquired by the GPS receiver 20 is displayed at the same time.

  In step 2, it is determined whether or not the measurement switch 22 is turned ON. If the determination is YES (measurement switch 22 ON), the process proceeds to step 3.

  In step 3, the laser oscillator 11, the scan mirror 14, and the oscillation monitor 15 start operating by turning on the measurement switch 22, and the insulating oil leakage detection operation shown in the flowchart of FIG. 11 is started.

  In FIG. 11, in step 11, the laser oscillator 11 is driven to emit laser light having a wavelength in the mid-infrared region (in the oil leakage inspection of insulating oil, for example, a wavelength band having a central wavelength of 3.6 μm) and control. The wavelength of the laser beam emitted by controlling the current applied to the laser oscillator 11 by the unit 17 is swept including the light absorption wavelength of the insulating oil to be inspected as shown in FIG. Irradiate the surface (inspection area) of the sealing equipment 2. At the same time, the scan mirror 15 is driven to scan the surface (inspection area) of the oil sealing equipment 2 with laser light. At this time, when the movable parts inside and outside the scan mirror 13 are directed to the maximum swing angle position based on the position information from the scan mirror 13, the control unit 17 drives the indication laser to make visible light. A laser is emitted. Thereby, since the visible light laser is irradiated to the contour portion of the inspection area, the operator can perform the oil leakage inspection while grasping the inspection area.

  In step 12, the received light intensity when the wavelength of the laser light is swept is detected. For example, the presence or absence of a drop in received light intensity based on the light absorption of the insulating oil is detected from the change state of the inclination of the received light intensity.

  In step 13, it is determined whether or not the drop in received light intensity is greater than or equal to a threshold value. For example, it is determined whether or not the ratio is equal to or greater than a preset threshold value by using a ratio between the maximum received light intensity and the drop amount when the wavelength is swept. When the ratio is equal to or greater than the threshold value and the determination is YES, it is determined that there is oil leakage and the process proceeds to step 14. If no drop in received light intensity is detected or if a drop in received light intensity is detected but the ratio is less than the threshold value and the determination is NO, it is determined that there is no oil leakage and step 14 is skipped to step 15. move on. The ratio between the maximum received light intensity when the wavelength is swept and the received light intensity itself at the wavelength where the drop in received light intensity occurs may be used as a determination value to determine whether the ratio is equal to or less than a threshold value. In this case, it is determined that there is oil leakage when it is below a preset threshold value.

  In step 14, the warning device 24 is driven to notify the operator who has the liquid leak detection device 10 that oil leakage has been detected. The operation of the warning device 24 may be stopped, for example, by setting the driving time of the warning device 24 in advance and automatically stopping after the set time elapses. A manual warning device stop switch is provided so that the operator can manually stop the operation. You may make it stop by. Further, a visible light laser is irradiated on the leaked portion detected by driving the instruction laser. Thereby, the operator can visually recognize the leaked part directly.

  In step 15, it is determined whether one scan of the scan mirror 13 is completed based on the swing angle information of the scan mirror 13. If the determination is YES, the process proceeds to step 16, and if the determination is NO, step 11 is performed. Repeat the operation of ~ 15. For example, the operations in steps 11 to 15 are performed every time the scan mirror 13 scans one pixel of a still image captured by the imaging device 16. By doing this, it is possible to create information such as a coloring instruction and a highlight instruction for each pixel in the still image obtained for each scanning period of the scanning mirror 13.

  In step 16, still image data scanned by the laser beam is recorded in the recording unit 19. In this image data, in addition to the basic information displayed on the standby screen such as the location information of the inspection place by the GPS receiver 20, a coloring instruction is given to the pixel position corresponding to the location where oil leakage is detected in the image And information such as a highlight instruction are added.

  In step 17, the image data recorded in step 16 from the recording unit 19 is read out and displayed on the display unit 18. Thereby, it is possible to objectively know in which part of the inspection area the oil leakage has occurred from the image on the display unit 19.

  The oil leakage detection operation shown in FIG. 11 ends when the measurement switch 22 is turned off.

  According to the liquid leakage detection device of this embodiment having such a configuration, even a trace amount of insulating oil that could possibly be overlooked by the eyes of a patrolman can be reliably detected. In addition, when oil leakage is detected, repair, replacement, soil replacement processing, and transition to reporting to the supervisory authorities can be made in a shorter period of time. Discover and deal with it without delay. Therefore, it is extremely effective for safety measures in electric power companies. Further, by using laser light having a wavelength in the mid-infrared region, it is possible to carry out an oil leak inspection even in the daytime when sunlight is present. Furthermore, since it is small and can be carried freely, it is possible to perform oil leakage inspection of insulating oil or the like at any place regardless of the place, extremely easily and efficiently.

  It is not always necessary to scan the laser beam, and the configuration may be such that the laser beam is simply emitted to the outside. However, if the configuration is such that the laser beam is scanned as in the above embodiment, the surface of the oil filling equipment 2 to be inspected Therefore, it is desirable to provide a scan mirror. In addition, although it is not always necessary to provide the imaging device 16, in the case of oil leakage inspection using an invisible laser beam such as a mid-infrared region, it is not possible to accurately identify the leakage, but the imaging device 16 is provided. If an oil leakage detection location is displayed as an image, the location of the oil leakage can be easily identified.

DESCRIPTION OF SYMBOLS 10 Liquid leak detection apparatus 11 Laser oscillator 12 Coaxial optical system 13 Scan mirror 14 Light-receiving part 16 Imaging device 17 Control part 18 Display part 19 Recording part 20 GPS receiver 24 Warning device

Claims (5)

A laser emitting means for generating laser light in a wavelength band having a central wavelength of 3.6 μm as a wavelength in the mid-infrared region irradiated to the inspection region for insulating oil leakage;
Wavelength sweep control means for sweeping and controlling the wavelength of the laser light including the light absorption wavelength band of the insulating oil to be inspected;
A light receiving means for receiving the reflected light of the laser light from the inspection region and generating an output according to the received light intensity;
A leak detection means for detecting the insulating oil leakage by detecting the drop in output of the light receiving means,
Warning means for warning the operator that the insulating oil leakage has been detected;
Position information acquisition means for acquiring position information of the inspection location of the insulating oil leakage;
With
The leak detection means determines whether the ratio is equal to or greater than a preset threshold value by using a ratio between the maximum received light intensity when the insulating oil is swept including the light absorption wavelength band and the amount of the drop as a determination value. A liquid leakage detection device for determining .   The liquid leakage detection apparatus according to claim 1, wherein the laser emission unit is a wavelength conversion laser emission unit that generates a laser beam having a wavelength in the mid-infrared region using a nonlinear optical effect.   3. The liquid leakage detection apparatus according to claim 1, further comprising: a coaxial optical system in which an optical axis of laser light projected from the laser emission unit to the outside of the apparatus and an optical axis of reflected light from the inspection region are coaxial.   An image processing means for recording the insulating oil leakage spot detected by the leak detection means and an inspection area image marked with the insulating oil leakage spot obtained by the image processing means are displayed on an image obtained by imaging the inspection area. The liquid leakage detection apparatus according to claim 1, further comprising: a display unit; and a data recording unit that records display image data of the display unit. The liquid leakage according to any one of claims 1 to 4 , further comprising: an indicating laser that emits a visible light laser for directly indicating an insulating oil leakage portion detected by the leakage detection means and an outline of the inspection region. Detection device.