JP2019124531A - Dust deposition detection device - Google Patents

Abstract

To provide a dust deposition detection device capable of detecting dust with a high degree of accuracy by eliminating an influence of temperature dependency and deterioration with time regardless of a type of dust.SOLUTION: The dust deposition detection device 130 includes a measurement system 136 (a first light emission part 132 and a first light detection part 134) arranged on a flat portion of electric equipment, a calibration system 142 (a second light emission part 138 and a second light detection part 140) arranged in an environment in which dust is not generated, a power supply part 104, a control part 108, a storage part 110, and a timer 112, the control part uses the measurement system and the calibration system to measure light quantity when a measurement time is reached, and compares a prescribed threshold with a ratio obtained by dividing the measured value of the measurement system by the measured value of the calibration system, and evaluate the degree of the deposition of the dust 202. Thus, the dust deposition detection device can detect the dust by eliminating temperature dependency and deterioration with time regardless of a type of dust.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a dust accumulation detection device for grasping the degree of dust adhering to or accumulated on an electric device, an electric facility or the like.

  In the electrical device or the electrical equipment, dust coming from the outside and accumulated increases the risk of malfunction of the electrical device or the electrical equipment or deterioration of the insulation. In order to secure the normal operation of these devices and equipment, it is necessary to implement measures such as periodic cleaning.

  Techniques for evaluating the degree of dust adhesion are known. For example, in Patent Document 1 below, two sets of two electrodes formed with a humidity sensitive film on which current easily flows when humidity gets higher are prepared, and one is installed in an environment where salt adheres, Should be installed in an environment where it is difficult for salt to adhere. By measuring and comparing the current values flowing between the electrodes of each set, the degree of contamination (salt adhesion) is determined.

  Further, in Patent Document 2 below, a light transmitting plate (dust accumulation plate) is provided in the air conditioning duct, and a light source and an optical sensor are disposed with the plate interposed therebetween, and the reduction amount of the transmitted light of the dust accumulation plate is Detect the accumulation of dust.

Patent No. 5488755 gazette JP 10-170438 A

  However, in Patent Document 1, there is a problem that only salt or dust containing salt can be detected. It is not sufficient to detect the risk of contact failure due to general dust adhesion or malfunction of the device.

  In Patent Document 2, the temperature dependence and the deterioration with time of the light source and the light detector are not taken into consideration. There is also a problem that it is necessary to place the light source and the photodetector opposite to each other, and it is not easy to reduce the number of parts.

  Therefore, a first object of the present invention is to provide a dust accumulation detection device capable of detecting accumulation of dust regardless of the type of dust. Another object of the present invention is to provide a dust accumulation detection device capable of detecting accumulation of dust with high accuracy by removing the influence of temperature dependency of the detector and deterioration with time.

  In the dust deposition detecting device according to the first aspect of the present invention, a light emitting unit for emitting light to a surface of a predetermined portion of an electric device, and a light detection for detecting light transmitted through the predetermined portion or light reflected by the predetermined portion The degree of dust accumulation on the predetermined portion is determined according to the ratio of the intensity of the light detected by the light detection portion to the intensity of the irradiation light of the light emitting portion in a state where the light is irradiated to the predetermined portion from the light emitting portion. And an evaluation unit to be evaluated. The angle formed by the light emitted from the light emitting unit and irradiated to the predetermined portion or the light detected by the light detecting unit with the surface of the predetermined portion is in the range of 5 degrees to 45 degrees.

  Thereby, regardless of the type of dust, it is possible to evaluate the degree of dust deposited on the electrical device.

  A dust accumulation detection device according to a second aspect of the present invention includes a light emitting unit that irradiates light to a predetermined part of an electric device, and a light detection unit that detects light transmitted through the predetermined part or light reflected by the predetermined part. And a control unit that controls lighting and extinguishing of the light emitting unit, and a predetermined value according to the intensity of light detected by the light detecting unit in a state where the light emitting unit is turned on by the control unit and the intensity of irradiation light of the light emitting unit. An evaluation unit that evaluates the degree of dust accumulation in the part; and a determination unit that determines whether the intensity of light detected by the light detection unit is less than or equal to a predetermined threshold when the light emission unit does not output light including. The evaluation unit evaluates the degree of dust accumulation based on the judgment that the judgment unit judges that the difference is equal to or less than the predetermined threshold value.

  As a result, measurement can be performed without being affected by ambient light, so that the degree of dust accumulation can be evaluated more accurately.

  Preferably, the dust accumulation detection device further includes a calibration light emission unit and a calibration light detection unit having the same optical configuration as the light configuration of the light emission unit and the light detection unit. The light emitting unit for calibration and the light detection unit for calibration are disposed in an environment in which dust is not easily accumulated. The evaluation unit evaluates the degree of dust accumulation in consideration of the intensity of light detected by the calibration light detection unit in a state where light is output from the calibration light emission unit and the intensity of the irradiation light of the calibration light emission unit. Do.

  As a result, it is possible to accurately evaluate the degree of dust accumulation by removing the effects of temperature dependency and time-dependent deterioration.

  More preferably, the dust accumulation detection device further includes a scattered light detection unit that detects light scattered by the predetermined portion, and the evaluation unit detects the scattered light detection unit when the degree of the dust accumulation is smaller than a predetermined value. The degree of dust accumulation in a predetermined portion is evaluated according to the ratio of the intensity of light detected by the light source to the intensity of light emitted from the light emitting unit.

  This makes it possible to detect dust even at a stage where the amount of dust accumulation is relatively small.

  More preferably, the dust accumulation detection device further includes a light shielding portion that shields light traveling from the periphery of the dust accumulation detection device to the light detection portion, and an air flow generation portion that generates a flow of air. The light shielding portion is disposed to direct the air flow generated by the air flow generation portion to a predetermined portion.

  Thereby, accumulation of dust can be accelerated, the necessity of inspection can be detected at an earlier stage, incidence of ambient light to the light receiving unit can be blocked, and the influence of ambient light on the measured value can be suppressed. The degree of dust deposition can be evaluated more accurately.

  Preferably, the predetermined portion has a plurality of reflecting surfaces including at least a reflecting surface having an L-shaped cross section, and the light emitting unit and the light detecting unit reflect light output from the light emitting unit by the plurality of reflecting surfaces. It is arranged to be detected by the light detection unit later.

  As a result, the light emitting unit and the light detecting unit can be disposed close to each other, the dust accumulation detecting device can be miniaturized, and the light emitting unit and the light detecting unit do not have to be opposed to each other. be able to.

  More preferably, the dust accumulation detector further includes a mechanism for changing the wavelength of the light emitted from the light emitting unit.

  Thereby, according to the kind of dust, accumulation of dust can be detected appropriately.

  More preferably, the dust deposition detection device further includes an imaging unit that images a predetermined portion, and the predetermined portion is formed of a metal that can be corroded by a corrosive gas.

  Thus, the dust accumulation detection device can be provided with a function as a corrosive gas sensor.

  Preferably, the dust accumulation detection device further includes a salt deposition sensor.

  This makes it possible to detect dust that contains particularly high risk salt, and enables comprehensive risk management.

  According to the present invention, regardless of the type of dust, dust can be detected, and risk management of equipment can be efficiently performed. In addition, it is possible to evaluate the degree of dust accumulation with high accuracy by removing the influence of temperature dependency and time-dependent deterioration.

FIG. 1 is a block diagram showing a schematic configuration of a dust accumulation detection device according to a first embodiment of the present invention. It is a sectional view showing an example of optical arrangement for detecting accumulation of dust. It is a flowchart which shows the dust accumulation detection process by the dust accumulation detection apparatus of FIG. It is a sectional view showing an example of optical arrangement for detecting accumulation of dust. It is a sectional view showing an example of optical arrangement for detecting accumulation of dust. It is a sectional view showing an example of optical arrangement for detecting accumulation of dust. It is a sectional view showing an example of optical arrangement for detecting accumulation of dust. It is sectional drawing which shows the structural example provided with the scattered light detection part. It is a block diagram which shows schematic structure of the dust accumulation detection apparatus which concerns on the 2nd Embodiment of this invention. It is a sectional view showing the composition of a proofreading system. It is a flowchart which shows the dust accumulation detection process by the dust accumulation detection apparatus of FIG. It is a flowchart which shows a modification. It is sectional drawing which shows a modification. It is a sectional view showing an example of composition for detecting corrosion by gas.

  In the following embodiments, the same parts are given the same reference numerals. Their names and functions are also identical. Therefore, detailed description about them will not be repeated.

First Embodiment
(Configuration of dust accumulation detector)
Referring to FIG. 1, the dust accumulation detection device 100 according to the first embodiment of the present invention includes a light emitting unit 102 that emits light, a power supply unit 104 that supplies power to the light emitting unit 102, and light that detects light. A detection unit 106, a control unit 108, a storage unit 110, and a timer 112 are included. The dust accumulation detection device 100 also includes a power supply (not shown) for operating each part.

  The light emitting unit 102 is, for example, an LED. The light emitting unit 102 is not limited to the LED, and may be a light emitting element capable of stably outputting light of a predetermined intensity in a predetermined direction for a predetermined time (for example, about 1 to several seconds). The power supply unit 104 supplies power for lighting the light emitting unit 102 to the light emitting unit 102 under the control of the control unit 108.

  The light detection unit 106 is, for example, a phototransistor. The light detection unit 106 is not limited to the phototransistor, and may be an element capable of detecting light emitted from the light emitting unit 102 and outputting an electric signal having a magnitude corresponding to the intensity (light amount). It is preferable that the light detection unit 106 have the central wavelength of the light emitted from the light emitting unit 102 in the vicinity of the center of the detection sensitivity.

  A flat light transmitting member 200 is disposed between the light emitting unit 102 and the light detecting unit 106. Specifically, referring to FIG. 2, the light transmitting member 200 is held by the flat holding member 120 around its periphery, and the holding member 120 is, for example, a flat portion of the electric device by a plurality of columnar support members 122. Supported on top of 250. 1 and 2 show the dust 202 deposited.

  A direction in which the intensity of light emitted from the light emitting unit 102 is maximum (hereinafter also referred to as an optical axis) obliquely enters the surface of the light transmitting member 200 at an angle θ. The light detection unit 106 is disposed to face the light emitting unit 102 so as to efficiently detect the light passing through the light transmitting member 200. The angle θ is preferably 5 to 45 degrees, more preferably 10 to 35 degrees.

  The control unit 108 is a CPU (Central Processing Unit), and controls the output of the power supply unit 104 to turn on or off the light emitting unit 102. For example, when the control unit 108 outputs a high level signal to the power supply unit 104, the power supply unit 104 supplies power to the light emitting unit 102. Thus, the light emitting unit 102 is lit. When the control unit 108 outputs a low level signal to the power supply unit 104, the power supply unit 104 stops the power supply to the light emitting unit 102. As a result, the light emitting unit 102 that has been lit turns off.

  Further, the control unit 108 obtains an output signal of the light detection unit 106 at a predetermined timing. For example, if the light detection unit 106 has an A / D conversion function, the control unit 108 acquires digital data output from the light detection unit 106. When the light detection unit 106 outputs an analog signal, the control unit 108 samples the input analog signal at predetermined time intervals to generate digital data.

  The storage unit 110 is a volatile or non-volatile memory that stores data input from the control unit 108. The timer 112 receives the request from the control unit 108 and outputs the current time.

(Detection processing of dust accumulation)
In the following, with reference to FIG. 3, a process of evaluating the degree of dust accumulation in the electric device by the dust accumulation detection device 100 of FIG. 1 will be described. The program of FIG. 3 is executed by the control unit 108. The program may be stored in, for example, the storage unit 110 in advance.

  Here, in the storage unit 110, it is assumed that the measurement time interval ΔT, the predetermined threshold value Th1, and the message are stored in advance. The measurement time interval ΔT is determined according to the deposition rate of the dust, the degree of the influence of the dust on the electric device, and the like. For example, the value is in the range of several hours to 24 hours. It is preferable to set a relatively short time if even slight dust accumulation has a significant impact on the performance, safety, etc. of the device.

  The threshold value Th1 is, for example, the light amount when the light amount of the light emitting unit 102 detected by the light detection unit 106 decreases due to the accumulation of dust and it is determined that maintenance (cleaning etc.) for removing dust is necessary. It corresponds. The threshold value Th1 can be set, for example, as a ratio to the initial (when the device is installed) measurement value as a reference. The initial measurement value of the light detection unit 106 is considered as a reference value representing the intensity of the light emitted from the light emission unit 102, and is stored in the storage unit 110 as a reference value A0.

  In step 300, the control unit 108 acquires the current time from the timer 112 as initial setting, and stores the current time in the storage unit 110 as the start time.

  In step 302, the control unit 108 acquires the current time from the timer 112 and calculates a time difference from the start time stored in step 300.

  In step 304, the control unit 108 compares the time difference calculated in step 300 with the measurement time interval ΔT stored in the storage unit 110 to determine whether or not the measurement time has come. That is, if the time difference is equal to or more than the measurement time interval ΔT, the control unit 108 determines that the measurement time has come, and shifts to step 306. Otherwise (time difference is less than the measurement time interval ΔT), control passes to step 314.

  In step 306, the control unit 108 updates the current start time. That is, the control unit 108 overwrites the start time of the storage unit 110 with the current time acquired in step 302.

  In step 308, the control unit 108 turns on the light emitting unit 102 and acquires an output signal from the light detecting unit 106. Specifically, as described above, the control unit 108 outputs a high level signal to the power supply unit 104 (power is supplied from the power supply unit 104 to the light emitting unit 102) to light the light emitting unit 102, and the state thereof Then, the output signal from the light detection unit 106 is acquired as the measurement value A1. When the output signal of the light detection unit 106 is obtained, the control unit 108 outputs a low level signal to the power supply unit 104 (stops the power supply from the power supply unit 104 to the light emission unit 102) and turns off the light emission unit 102. .

  In step 310, control unit 108 stores in memory unit 110 a value (A1 / A0) obtained by dividing measurement value A1 obtained in step 308 by reference value A0 read from memory unit 110. It is determined whether it is equal to or less than Th1. Being less than or equal to the threshold Th1 means that dust accumulation has progressed to a certain extent that the maintenance needs to be performed. If it is determined that the threshold value Th1 or less, the control proceeds to step 312. Otherwise, control transfers to step 314.

  In step 312, the control unit 108 reads and presents a predetermined message from the dust accumulation detection device 100. For example, a message stating that maintenance needs to be performed is presented. If the dust accumulation detection device 100 includes an audio output device or an image display device, the message can be presented as an audio or an image. Data representing a message to be presented may be output from the dust accumulation detection device 100 to an external sound output device or an image display device.

  In step 314, the control unit 108 determines whether an end instruction has been received. If an instruction to end is received, this program ends. Otherwise, control returns to step 302 to repeat the above process. The end instruction is performed, for example, by an operation of turning off the dust accumulation detector 100.

  As described above, the dust accumulation detection device 100 measures the amount of light passing through the light transmission member 200 and the dust 202 by the light detection unit 106 with the light emission unit 102 lit at a predetermined time interval ΔT, and the measurement value The ratio of the reference value to the reference value (initial value) is compared with the threshold value Th1. The measured value is influenced by the presence of the dust 202 of the light transmitting member 200, which depends mainly on the degree of deposition (the amount of deposition) regardless of the type of dust, such as whether it is a dust containing salt or not. Therefore, the dust accumulation detection device 100 can evaluate the degree of the dust accumulated on the light transmitting member 200 regardless of the type of dust. It is considered that dust of the same degree is accumulated in the vicinity of the light transmitting member 200 of the device, so if the measured value of the light detection unit 106 becomes equal to or less than the threshold value Th1, the dust accumulation detecting device 100 performs maintenance. Suggested messages etc. can be presented. By setting the threshold Th1 appropriately, maintenance can be promoted to remove dust by maintenance before dust deposition causes deterioration of the performance and safety of the device, etc., and the equipment is properly managed. it can.

  By making the light from the light emitting unit 102 obliquely incident on the light transmitting member 200, it is possible to lengthen the light path passing through the accumulated layer of dust, so even when the amount of accumulated dust is small, the light detecting unit The amount of light measured by 106 becomes a relatively small value. Therefore, the deposition of dust can be detected at an earlier stage, and a message can be presented earlier.

  In the above, the light emitting unit 102 and the light detecting unit 106 are disposed across the surface of the light transmitting member 200 on which the dust 202 is deposited, and light is irradiated from one surface of the dust deposition layer. Although the case of measuring the light quantity output to the surface has been described, the present invention is not limited to this. The arrangement of the light emitting unit 102 and the light detecting unit 106 is arbitrary, and can be appropriately changed according to the part of the electric device to be subjected to the dust accumulation detection, the structure around it, an empty space, and the like.

  For example, as shown in FIG. 4, the light emitting unit 102 and the light detecting unit 106 may be disposed. Also in this case, the emitted light of the light emitting unit 102 is detected by the light detecting unit 106 through the dust 202 and the light transmitting member 200. The amount of light measured by the light detection unit 106 changes according to the amount of dust 202 deposited on the light transmitting member 200, and becomes smaller as the amount of dust 202 deposited increases. Therefore, even if the configuration of FIG. 4 is used, maintenance can be promoted at an appropriate time according to the degree of dust accumulation regardless of the type of dust by the same processing as that of FIG. 3. The angle θ between the light emitted from the light emitting unit 102 and the surface of the light transmitting member 200 is preferably the angle described above with reference to FIG.

  Further, as shown in FIG. 5, both the light emitting unit 102 and the light detecting unit 106 may be disposed on the side of the surface of the light transmitting member 200 on which the dust 202 is deposited. In FIG. 5, a light reflection member 204 is provided instead of the light transmission member 200 of FIG. The surface of the light reflecting member 204 on which the dust 202 is deposited is a mirror surface that reflects the light from the light emitting unit 102. With the configuration of FIG. 5, the support member 122 shown in FIG. 2 may not be provided, and the light reflection member 204 can be disposed directly on the flat portion 250.

  The emitted light of the light emitting unit 102 is reflected by the light reflecting member 204 after passing through the dust 202 and is detected by the light detecting unit 106 after passing through the dust 202. The amount of light measured by the light detection unit 106 changes in accordance with the amount of dust 202 deposited on the light reflecting member 204, and becomes smaller as the amount of dust 202 deposited increases. Therefore, even if the configuration of FIG. 5 is used, maintenance can be promoted at an appropriate time according to the degree of dust accumulation regardless of the type of dust, by the same processing as that of FIG. 3. The angle θ between the light emitted from the light emitting unit 102 and the surface of the light reflecting member 204 is preferably the angle described above with reference to FIG.

  Further, as shown in FIG. 6A, an L-shaped light reflecting member 206 having an L-shaped cross section may be provided instead of the light transmitting member 200 shown in FIG. The two orthogonal surfaces of the L-shaped light reflecting member 206 on the light emitting unit 102 side are mirror surfaces that reflect the light from the light emitting unit 102. The light from the light emitting unit 102 passes through the dust 202, is reflected by the L-shaped light reflecting member 206, passes through the dust 202 again, and is then reflected by the L-shaped light reflecting member 206, and the light of the light emitting unit 102 It returns parallel to the axis and is detected by the light detection unit 106. The amount of light measured by the light detection unit 106 changes in accordance with the amount of dust 202 deposited on the L-shaped light reflecting member 206, and becomes smaller as the amount of dust 202 deposited increases. Therefore, even if the configuration of FIG. 6A is used, maintenance can be promoted at an appropriate time according to the degree of dust accumulation regardless of the type of dust by the same processing as that of FIG. The angle θ between the light emitted from the light emitting portion 102 and the surface of the L-shaped light reflecting member 206 on which the dust 202 is deposited is preferably the angle described above with reference to FIG.

  By configuring as shown in FIG. 6A, the light detection unit 106 can be disposed near the light emitting unit 102, which is more compact than the configurations of FIG. 2, FIG. 4 and FIG. Also, for example, a known photo reflector, which is an element in which an LED and a phototransistor are housed in one package, can be used, and the number of parts can be reduced.

  The L-shaped cross section means not only the case where the two planes are orthogonal but also the case where the two planes are substantially orthogonal. That is, the angle between the two reflecting surfaces of the L-shaped reflecting member 206 is not limited to 90 degrees, and may be an angle close to 90 degrees. Even in such a case, the light from the light emitting unit 102 is reflected twice by the L-shaped light reflecting member 206 and returns substantially parallel to the optical axis of the light emitting unit 102. It can be placed nearby.

  Further, the configuration shown in FIG. 6B in which the light emitting unit 102 and the light detecting unit 106 are replaced in FIG. 6A may be used. In FIG. 6B, the light emitted from the light emitting unit 102 is reflected by the L-shaped light reflecting member 206, passes through the dust 202, is reflected by the L-shaped light reflecting member 206, and is again reflected by the dust 202. After passing, it returns parallel to the optical axis of the light emitting unit 102 and is detected by the light detecting unit 106. In this case, the light emitted from the light emitting unit 102 and reflected twice by the surface of the L-shaped light reflecting member 206 is incident on the light detecting unit 106, and the dust 202 of the L-shaped light reflecting member 206 The angle θ formed with the surface to be deposited is preferably 5 to 45 degrees, more preferably 10 to 35 degrees, as described above.

  If the light emitted from the light emitting unit 102 is not in the plane orthogonal to the two reflecting surfaces of the L-shaped reflecting member 206, the light path after being reflected twice by the L-shaped light reflecting member 206 is As shown in FIGS. 6A and 6B, it is not parallel to the optical axis of the light emitting unit 102. However, even in such a case, if a reflective surface that reflects light twice reflected by the L-shaped light reflective member 206 is further provided, dust and dirt can be obtained by adjusting the position and angle of the reflective surface. The light path after being reflected can be made parallel to the optical axis of the light emitting unit 102 without affecting the deposition of the light. Therefore, the light emitting unit 102 and the light detecting unit 106 can be disposed close to each other.

  Further, as shown in FIG. 7, the light emitting unit 102 and the light detecting unit 106 may be disposed. The light emitted from the light emitting unit 102 passes through the light transmitting member 208 and the dust 202, is reflected by the light reflecting member 210, and is detected by the light detecting unit 106. The amount of light measured by the light detection unit 106 changes in accordance with the amount of dust 202 deposited on the light transmitting member 208, and decreases as the amount of dust 202 deposited increases. Therefore, even if the configuration of FIG. 7 is used, maintenance can be promoted at an appropriate time according to the degree of dust accumulation regardless of the type of dust, by the same processing as that of FIG. 3. The angle θ between the light emitted from the light emitting unit 102 and the surface of the light transmitting member 208 is preferably the angle described above with reference to FIG.

  Although the case where the light detection unit 106 detects the emitted light of the light emitting unit 102 which has passed through the dust 202 has been described above, the present invention is not limited thereto. As shown in FIG. 8, a scattered light detection unit 124 may be provided in addition to the configuration of FIG. 2. The scattered light detection unit 124 is an element similar to the light detection unit 106, and is, for example, a phototransistor. The light from the light emitting unit 102 passes through the light transmitting member 200, passes through the dust 202, and is detected by the light detecting unit 106. However, part of the light is scattered by particles of the dust. Since the scattered light is also emitted to the side of the light emitting unit 102 as shown by a plurality of downward arrows in FIG. 8, the light can be detected by the scattered light detection unit 124. If the dust 202 does not deposit on the light transmitting member 200, most of the light emitted from the light emitting unit 102 is detected by the light detecting unit 106, and the scattered light can not be detected by the scattered light detecting unit 124. When the dust 202 starts to deposit on the surface 200, scattering occurs, which can be detected by the scattered light detection unit 124. Although it is difficult to detect dust if the dust does not deposit to a certain extent in the measurement value of the light detection unit 106, the scattered light detection unit 124 can detect dust even at a stage where the amount of dust deposition is relatively small. The measurement by the scattered light detection unit 124 is effective for detecting a minute amount of dust.

  The threshold value Ths related to the measurement value of the scattered light detection unit 124 is set to a value different from the threshold value Th1 related to the measurement value of the light detection unit 106. Then, when the measurement value of the scattered light detection unit 124 becomes equal to or greater than the threshold value Ths, it is determined that dust has accumulated, and a predetermined message can be presented in the same manner as described above. The threshold value Ths can be set, for example, as a ratio to the intensity (light amount) of light or a reference value (for example, the emission light intensity of the light emitting unit 102 at the time of installation of the dust accumulation detection device).

  The position of the scattered light detection unit 124 for detecting the scattered light may be the same side as the light emitting unit 102 with respect to the surface of the light transmitting member 200, but a part of the light of the light emitting unit 102 is the light transmitting member 200. It is preferable that the reflected light is not incident on the scattered light detection unit 124 because the light is reflected by the light source. That is, in FIG. 8, the position of the scattered light detection unit 124 in the left-right direction is substantially the same position as the position where the light of the light emitting unit 102 is incident on the light transmitting member 200 or is closer to the light emitting unit 102 than that. Is preferred.

  Also, the measured value is affected by the size of dust and the wavelength of the light emitted from the light emitting unit 102. For example, if the wavelength is sufficiently larger than the particle size, scattered light is unlikely to occur. Therefore, by changing the wavelength emitted from the light emitting unit 102, it is possible to more appropriately detect the degree of dust accumulation in accordance with the type of dust (for example, the size of the particle).

Second Embodiment
In the first embodiment described above, the measured value has temperature dependency, and the measured value is affected by aging. The second embodiment is for removing the effects of temperature dependency and aging of the detector.

(Configuration of dust accumulation detector)
Referring to FIG. 9, the dust accumulation detection device 130 according to the second embodiment of the present invention includes a first light emitting unit 132, a first light detecting unit 134, a power supply unit 104, a control unit 108, a storage unit 110, The timer 112 includes a second light emitter 138 and a second light detector 140. The dust accumulation detection device 130 also includes a power supply (not shown) for operating each part.

  The first light emitting unit 132 and the first light detecting unit 134 respectively correspond to the light emitting unit 102 and the light detecting unit 106 in FIG. 1, and the light emitting unit 102 in FIGS. 1 and 2 for the light transmitting member 200 and the dust 202. And the light detection unit 106. That is, the first light emitting unit 132, the first light detecting unit 134, the power supply unit 104, the light detecting unit 106, the control unit 108, the storage unit 110, and the timer 112 are configured in the same manner as in FIG. Therefore, redundant description on these will not be repeated.

  The dust accumulation detector 130 (FIG. 9) differs from the dust accumulation detector 100 (FIG. 1) in that it includes a second light emitter 138 and a second light detector 140. The power supply unit 104 also supplies power to the second light emitting unit 138 under the control of the control unit 108. The second light emitting unit 138 receives power supply from the power supply unit 104 and lights up, and turns off when the power supply is stopped. The emitted light of the second light emitting unit 138 is detected by the second light detecting unit 140, and the measurement signal output from the second light detecting unit 140 is input to the control unit 108.

  Here, the configuration of the second light emitting unit 138 and the second light detecting unit 140 is referred to as a calibration system 142, and is distinguished from the first light emitting unit 132 and the measurement system 136 of the first light detecting unit 134. The difference between the measurement system 136 and the calibration system 142 is whether or not the light transmitting member 200 and the dust 202 are included.

  The second light emitting unit 138 is an element of the same type as the first light emitting unit 132, and the second light detecting unit 140 is an element of the same type as the first light detecting unit 134. Here, when using LEDs for the first light emitting unit 132 and the second light emitting unit 138, for example, the same type of device uses LEDs of the same part number of the same manufacturer. When phototransistors are used for the first light detection unit 134 and the second light detection unit 140, phototransistors of the same manufacturer and the same part number are used.

  Specifically, the second light emitter 138 and the second light detector 140 are arranged as shown in FIG. The second light emitting unit 138 and the second light detecting unit 140 are surrounded by the dustproof member 144 so that dust is less likely to be generated. The second light emitting unit 138 and the second light detecting unit 140 have the same optical configuration as the first light emitting unit 132 and the first light detecting unit 134. That is, the second light emitting unit 138 and the second light detecting unit 140 may be separated by the same distance as the first light emitting unit 132 and the first light detecting unit 134, and may be similar to the first light emitting unit 132 and the first light detecting unit 134. It is arranged facing each other. Therefore, when the same power is supplied from the power supply unit 104 to the first light emitting unit 132 and the second light emitting unit 138, the light transmitting member 200 and the dust 202 are not present in the measurement system 136, and variations in element characteristic values, arrangement error, etc. If it can be ignored, the measurement values of the first light detection unit 134 and the second light detection unit 140 become the same value.

  When the electric device including the dust accumulation detector 130 is installed, the dust 202 is not accumulated on the light transmitting member 200. Therefore, as described above, the first light detection unit 134 and the second light detection unit 140 The measured values are the same value. Thereafter, as time passes, in the measurement system 136, the dust 202 is deposited on the light transmitting member 200, so the measured value of the first light detection unit 134 decreases, but the second light detection unit 140 of the calibration system 142. The measured value is not affected by dust by the dustproof member 144.

  The light amount of the first light emitting unit 132 and the second light emitting unit 138 decreases with time, and the detection sensitivity of the first light detecting unit 134 and the second light detecting unit 140 also decreases with time. In addition, the change in temperature environment affects the light amounts of the first light emitting unit 132 and the second light emitting unit 138 and the detection sensitivity of the first light detecting unit 134 and the second light detecting unit 140. However, changes over time and changes in the temperature environment affect the measurement values of measurement system 136 and calibration system 142 as well. Therefore, the difference between the measurement values of the first light detection unit 134 and the second light detection unit 140 is due to the accumulation of the dust 202, and from the difference between the measurement values of the first light detection unit 134 and the second light detection unit 140. The degree of accumulation of dust 202 in the measurement system 136 can be evaluated.

(Detection processing of dust accumulation)
Hereinafter, with reference to FIG. 11, the dust accumulation detector 130 of FIG. 9 is used to specifically explain the process of evaluating the degree of dust accumulation in the target device by removing the temperature dependency and the influence of time-dependent deterioration. Do. The program of FIG. 11 is executed by the control unit 108. The program may be stored in, for example, the storage unit 110 in advance.

  FIG. 11 differs from FIG. 3 only in that step 308 (FIG. 3) is replaced by steps 400-404. Therefore, here, the steps 400 to 404 will be mainly described.

  As in the first embodiment, the storage unit 110 stores in advance the measurement time interval ΔT, the reference value (initial measurement value) A0, the first threshold (ratio to the reference value) Th1, and a message in advance. It is assumed that

  As in the first embodiment, the processes of steps 300 to 304 are repeated, and when the measurement time comes, the process of step 306 is performed, and then in step 400, the control unit 108 controls the amount of light by the measurement system 136. Perform the measurement. That is, the control unit 108 turns on the first light emitting unit 132 and acquires an output signal of the first light detecting unit 134. Specifically, the control unit 108 outputs a high level signal to the power supply unit 104 (supply power from the power supply unit 104 to the first light emitting unit 132), and causes the first light emitting unit 132 to light up, and in that state The output signal from the first light detection unit 134 is acquired as the measurement value A1. When the output signal of the first light detection unit 134 is acquired, the control unit 108 outputs a low level signal to the power supply unit 104 (stops the power supply from the power supply unit 104 to the first light emitting unit 132), The light emitting unit 132 is turned off.

  In step 402, the control unit 108 performs measurement of the light amount by the calibration system 142. That is, the control unit 108 turns on the second light emitting unit 138 and acquires an output signal of the second light detecting unit 140. Specifically, the control unit 108 outputs a high level signal to the power supply unit 104 (power is supplied from the power supply unit 104 to the second light emitting unit 138), and the second light emitting unit 138 is turned on. The output signal from the second light detection unit 140 is acquired as the measurement value A2. When the output signal of the second light detection unit 140 is acquired, the control unit 108 outputs a low level signal to the power supply unit 104 (stops the power supply from the power supply unit 104 to the second light emitting unit 138), The light emitting unit 138 is turned off.

  In step 404, the control unit 108 divides the measurement value A1 acquired in step 400 by the measurement value A2 acquired in step 402 to calculate a ratio (A1 / A2).

  Subsequently, the processes of steps 310 to 314 are executed using this ratio, as in the first embodiment.

  As described above, the measured value (light intensity) depends on the temperature at the time of measurement, is affected by deterioration with time, and depends on the amount of dust. When the respective effects are represented by α, β and γ, the measured value A1 of the measurement system is A1 = α · β · γ · A0. Further, as described above, since the initial value of the calibration system is considered to be the same as the initial value A0 of the measurement system, the measurement value A2 of the calibration system is A2 = α · β · A0. From these equations, γ = A1 / A2. That is, the amount of dust can be evaluated by excluding the influence of temperature at the time of measurement and the influence of aging with the value obtained by dividing the measurement value A1 of the measurement system by the measurement value A2 of the calibration system.

  Therefore, similar to the dust accumulation detection device 100 of the first embodiment, the dust accumulation detection device 130 can evaluate the degree of dust accumulated on the light transmitting member 200 regardless of the type of dust. . When the threshold Th1 or less is reached, the dust accumulation detection device 130 can present a predetermined message. By setting the threshold Th1 appropriately, maintenance can be promoted to remove dust by maintenance before dust deposition causes deterioration of the performance and safety of the device, etc., and the equipment is properly managed. it can. In particular, since the measurement results from which the temperature dependency and the influence of aging are removed are used, it is possible to accurately evaluate the degree of dust accumulation.

(Modification 1)
In the above, the case where the measurement is performed after the predetermined time has been described, but if the electric device is installed in an environment affected by sunshine or illumination, depending on the time zone, the first light detection unit 134 and There is a possibility that the second light detection unit 140 can not accurately evaluate the degree of dust accumulation under the influence of ambient light. In such a case, the dust accumulation detection device 130 preferably performs the process shown in the flowchart of FIG. 12. In the flowchart of FIG. 12, the measurement is performed only when the dark environment is reached.

  Here, it is assumed that the second threshold value Th2 is stored in advance in the storage unit 110. The second threshold value Th2 is a value equivalent to the value measured by the first light detection unit 134 in a dark environment such as night time.

  In FIG. 12, steps 500 and 502 are added between the steps 306 and 400 in FIG. The processing of steps 300 to 304 is repeated, and when the measurement time comes, the processing of step 306 is performed, and then in step 500, the control unit 108 performs, for example, the first light detection while the first light emitting unit 132 is turned off. An output signal from unit 134 is obtained as a measurement value.

  In step 502, the control unit 108 determines whether the measured value obtained in step 502 is equal to or less than the second threshold value Th 2 read from the storage unit 110. If the second threshold value Th2 or less, the control proceeds to step 400, and the processing of the subsequent steps is performed. Otherwise, control transfers to step 314.

  Accordingly, when the dust deposition detection device 130 does not turn on the first light emitting unit 132 and the value measured by the first light detecting unit 134 is equal to or less than the second threshold value Th2, that is, in a dark environment Since the measurement is performed by the measurement system 136 and the calibration system 142 only as described above, the degree of dust accumulation can be evaluated more accurately.

(Modification 2)
Although the case where the degree of dust accumulation is evaluated in the normal use state of the electric device has been described above, dust accumulation may be accelerated as shown in FIG. In FIG. 13, a light shielding / airflow guiding plate 214 which adopts the configuration shown in FIG. 6A and is disposed to prevent the ambient light from entering the heater 212 and the light receiving unit of the light detecting unit 106. Is equipped. When the heater 212 is energized, the air around it is heated to generate an upward air flow, and the light shielding / air flow guiding plate 214 is provided to generate an air flow indicated by an arrow in FIG. Therefore, the dust 202 is easily deposited on the L-shaped light reflecting member 206 disposed on the right side of FIG. The configuration shown in FIG. 6B may be adopted to provide the heater 212 and the light shielding / airflow guiding plate 214 as in FIG.

  By accelerating dust accumulation in this manner, the need for inspection can be detected earlier. In addition, the light shielding / air flow guiding plate 214 can block the incidence of environmental light on the light receiving unit of the light detecting unit 106, and can suppress the influence of the environmental light on the measurement value of the light detecting unit 106. Therefore, the degree of dust accumulation can be evaluated more accurately.

(Modification 3)
Depending on the electrical equipment, corrosive gases may be used. In addition, electrical devices may be used in environments where corrosive gases are likely to be generated. Therefore, in addition to the evaluation of the degree of dust accumulation, it is preferable if the influence of the corrosive gas can be evaluated.

  For that purpose, for example, as shown in FIG. 14, a metal member 216 is provided instead of the light reflecting member 204 of FIG. 5, and an imaging unit 146 is further provided. The metal member 216 is formed in a mirror shape so as to reflect the emission light of the light emitting unit 102, and is formed of, for example, silver (Ag) or copper (Cu).

  For example, at the time of measurement in step 308 of FIG. 3 and step 400 of FIG. 11, the imaging unit 146 simultaneously images the surface of the metal member 216 and displays the imaged image on a display device such as a liquid crystal panel. Since silver or copper is blackened when corroded by hydrogen sulfide gas, the color of the image of the metal member 216 captured by the imaging unit 146 can be used to evaluate the degree of corrosion by the hydrogen sulfide gas.

  The corrosive gas is sulfur dioxide gas, chlorine gas, etc. in addition to hydrogen sulfide gas, but if the metal member 216 is formed of a metal according to the object to be detected, the color of the surface of the metal member 216 changes as well. The degree can be assessed. For example, in the case of sulfur dioxide gas, an iron-nickel alloy can be used.

  Moreover, you may combine with a well-known salt adhesion sensor (refer patent document 1). The salt deposition sensor can detect particularly high risk dirt containing salt, and together with the above-described detection of dust deposition, it is possible to perform comprehensive risk management of the electric device.

  Although the present invention has been described above by describing the embodiment, the above-described embodiment is an exemplification, and the present invention is not limited to the above-described embodiment. The scope of the present invention is defined by each claim of the claims in consideration of the description of the detailed description of the invention, and all the changes within the meaning and range equivalent to the words and phrases described therein Including.

100, 130 Dust accumulation detector 102 Light emitting unit 104 Power supply unit 106 Light detecting unit 108 Control unit 110 Storage unit 112 Timer 120 Holding member 122 Support member 124 Scattered light detecting unit 132 First light emitting unit 134 First light detecting unit 136 Measuring system 138 second light emitting unit 140 second light detecting unit 142 calibration system 144 dustproof member 146 imaging unit 200, 208 light transmitting member 202 dust 204, 210 light reflecting member 206 L-shaped light reflecting member 212 heater 214 light shielding / airflow guiding plate 216 Metal member 250 flat part

Claims (6)

Light emitting means for emitting light to a surface of a predetermined part of the electrical device;
A light detection unit that detects light transmitted through the predetermined portion or light reflected by the predetermined portion;
According to the ratio of the intensity of the light detected by the light detecting means to the intensity of the light emitted by the light emitting means in the state where the predetermined part is irradiated with light from the light emitting means, the dust is accumulated on the predetermined part And evaluation means for evaluating the degree,
The angle formed by the light emitted from the light emitting means and irradiated to the predetermined part or the light detected by the light detecting means with the surface of the predetermined part is in the range of 5 degrees to 45 degrees. Dust accumulation detector that features. Light emitting means for emitting light to a predetermined part of the electrical device;
A light detection unit that detects light transmitted through the predetermined portion or light reflected by the predetermined portion;
Control means for controlling lighting and extinguishing of the light emitting means;
The control unit evaluates the degree of dust accumulation on the predetermined portion according to the intensity of the light detected by the light detection unit and the intensity of the irradiation light of the light emission unit in a state in which the control unit lights the light emission unit Evaluation means,
Determining means for determining whether the intensity of light detected by the light detection means is less than or equal to a predetermined threshold value in a state where the light emission means does not output light;
A dust deposition detecting device characterized in that the evaluation means evaluates the degree of dust accumulation in response to the judgment that the judgment means is less than or equal to the predetermined threshold value. It further includes a light emitting means for calibration and a light detection means for calibration having the same optical configuration as the optical configuration of the light emitting means and the light detection means,
The calibration light emitting means and the calibration light detection means are disposed in an environment where dust is less likely to deposit.
The evaluation means considers the intensity of light detected by the calibration light detection means in the state where light is output from the calibration light emission means, and the dust in consideration of the intensity of the irradiation light of the calibration light emission means. The dust accumulation detector according to claim 1 or 2, wherein the degree of accumulation is evaluated. It further includes scattered light detection means for detecting light scattered by the predetermined portion,
When the degree of dust accumulation is smaller than a predetermined value, the evaluation means determines the predetermined according to a ratio between the intensity of light detected by the scattered light detection means and the intensity of light emitted by the light emission means. The dust accumulation detector according to any one of claims 1 to 3, wherein the degree of dust accumulation in the part is evaluated. A light shielding means for shielding light from the periphery of the dust accumulation detector toward the light detection means;
And air flow generating means for generating an air flow,
5. The dust accumulation detector according to any one of claims 1 to 4, wherein the light shielding means is arranged to direct the air flow generated by the air flow generation means to the predetermined portion. The predetermined portion has a plurality of reflective surfaces including at least a reflective surface having an L-shaped cross section,
The light emitting means and the light detecting means are arranged such that the light output from the light emitting means is detected by the light detecting means after being reflected by the plurality of reflecting surfaces. The dust accumulation detection device according to any one of claims 1 to 5.

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