JP6587122B2 - Oil property detection method and oil property detection device - Google Patents

Description

  The present invention relates to an oil property detection method and an oil property detection device that detect oil properties (viscosity and the like) existing in one region (region to be searched) from a distance without contact.

  For example, oil (heavy oil, light oil) spilled from a ship or the like floats on the water. Detecting the presence of such oil is important for the safety of navigation of ships and the environment management. In particular, since the range in which oil should be detected becomes extremely wide at sea, it is necessary to detect this from a distance without contact. For this reason, a technique for detecting oil on water using light has been proposed.

  Patent Document 1 describes a technique for recognizing oil floating on the sea by scanning the sea with laser light and detecting the fluorescence emitted after the oil absorbs this laser light (excitation light). . Here, in detecting fluorescence emitted by oil, there is a possibility that objects other than oil (for example, floating organisms) on the water or in water may be detected at the same time, but the wavelength of the fluorescence is specific to the substance emitting the fluorescence. Therefore, oil can be detected with high sensitivity by detecting only the fluorescence emitted by the oil by using a filter that transmits light of a specific wavelength. In addition, since the wavelength of the excitation light necessary to emit fluorescence also differs depending on the substance or the wavelength of the fluorescence, optimizing the wavelength of the laser light used as the excitation light for oil detection is particularly suitable for oil detection. Can be made.

  Patent Document 2 also describes a technique for detecting oil by detecting fluorescence from oil in the same manner. In this technique, the leakage of oil is performed by performing two imaging operations, excitation light irradiation and excitation light non-irradiation, and comparing the former image data and the latter image data as difference images. Is detected based on a change in luminance.

  In the above technique, the wavelength of the fluorescence is used as a guide for selecting the fluorescence emitted by the oil. On the other hand, in the technique described in Patent Document 3, not only the wavelength but also the oil polarization is examined to detect the oil, thereby further improving the discrimination ability between the oil and other substances. Oil leak is detected.

JP 2000-275135 A JP 2011-185757 A JP 2007-101228 A

  With the above technique, oil floating on the sea can be detected with high sensitivity. However, only the presence and distribution of oil on the water at the time of detection was detected by the above technique. On the other hand, not only the presence or absence of oil but also information on the viscosity, type, etc. (property) of this oil is necessary for the safety of navigation of ships and the environment management. However, it has been difficult to recognize the properties of these oils by any of the above techniques. It was also difficult to examine the properties of these oils without contact with the oil.

  That is, it is difficult to detect oil existing in one region and to detect its property from a distance without contact.

  The present invention has been made in view of such problems, and an object of the present invention is to detect oil existing in one region and to detect its property from a distance without contact.

In order to solve the above problems, the present invention has the following configurations.
An oil property detection method according to claim 1 of the present invention is configured to irradiate an area of water with excitation light, and detect fluorescence emitted after oil existing in the area absorbs the excitation light. An oil property detection method for detecting the property of the oil, wherein the excitation light is light oscillated in a pulsed manner in a linearly polarized state in one direction, and the oil is irradiated with the excitation light. The viscosity of the oil is detected based on the passage of time of the degree of depolarization of fluorescence as the intensity ratio of polarized components in two directions perpendicular to the fluorescence in the detection target light that is light emitted by the oil. And
In the present invention, the viscosity of the oil existing in one region is detected based on the passage of time of the intensity ratio (fluorescence depolarization degree) of the polarization components in two perpendicular directions in the fluorescence. Here, this region is an area of water.
In the oil property detection method according to claim 2 of the present invention, the temperature of the oil is measured in a non-contact manner, or the temperature around the oil in the region is measured, and the detected viscosity is measured. based on the temperature, and estimates the viscosity at a particular reference temperature.
In this invention, the temperature of the oil or its surroundings is measured, and the viscosity of the oil at the reference temperature is estimated based on the estimated viscosity and the measured temperature. In order to measure the temperature around the oil, the temperature may be measured not only by a non-contact type but also by a contact type thermometer.

The oil property detection method according to claim 3 of the present invention is characterized in that the type of oil is estimated from the passage of time of the degree of fluorescence depolarization .
In the present invention, the type of oil spilled is estimated by the above method.
Properties detection method of oil according to claim 4 of the present invention, the fluorescent data of the time course of the degree of depolarization previously acquired for each type of the oil, actually measured the fluorescence polarization of the elapsed time and the data was Based on the above, the type is estimated.
In the present invention, in the estimation of the type of oil described above, data on the passage of time of the degree of depolarization of fluorescence previously acquired for each oil type is used.
In the oil property detection method according to claim 5 of the present invention, the temperature of the oil is measured in a non-contact manner, or the temperature around the oil in the region is measured, and the measured fluorescence depolarization degree is measured. The type is estimated based on the passage of time, the data, and the temperature.
In the present invention, the temperature of the oil or its surroundings is measured and this information is also used for estimating the type of oil. In order to measure the temperature around the oil, the temperature may be measured not only by a non-contact type but also by a contact type thermometer.
In the oil property detection method according to claim 6 of the present invention, the oil is a mineral oil.
In this invention, the property regarding the spilled mineral oil is recognized.
In the oil property detection method according to claim 7 of the present invention, one of the two directions corresponds to a polarization direction of the excitation light.
In the present invention, when the excitation light irradiated or its polarization direction is changed, the changed polarization direction is set to one of the two directions .
The oil property detection method according to claim 8 of the present invention is characterized in that the wavelength of the excitation light is in the range of 250 nm to 450 nm.
In the present invention, the wavelength of the excitation light is in the range of 250 nm to 450 nm, that is, the excitation light is light on the ultraviolet light side than visible light.

An oil property detection apparatus according to claim 9 of the present invention is configured to irradiate an area of water with excitation light, and detect fluorescence emitted after oil existing in the area absorbs the excitation light. An oil property detection device for detecting the property of the oil, wherein the excitation light is a light source that emits the excitation light oscillated in a pulsed manner in a linearly polarized state in one direction, and the oil is the excitation light. A first light detection unit for detecting the intensity of the first detection light that is a component of the fluorescence polarized in the first direction in the detection target light that is the light emitted from the oil after being irradiated at the time and the passage of time thereof; a second optical detector for detecting the course the intensity of the second detection light which is a component of the fluorescence is polarized in the first direction perpendicular to the second direction in the detection target light and that time, the first Fluorescence depolarization as intensity ratio of detection light and second detection light Characterized by comprising a an analysis unit for detecting the viscosity of the oil based on the time elapsed.
In the present invention, the first light detector for detecting the two directions of polarization components differ in oil emitted fluorescence, the second light detector is used, the time course of the ratio of these outputs (fluorescence polarization degree) Based on this, the viscosity of the oil present in a region on the water is detected .
The oil property detection apparatus according to claim 10 of the present invention is characterized in that one of the first direction and the second direction corresponds to a polarization direction of the excitation light.
In this invention, when the polarization direction of the irradiated excitation light or the elastic scattered light of the excitation light is changed from the excitation light, the polarization direction of the elastic scattered light is one of the first direction and the second direction. One way.

The oil property detection device according to claim 11 of the present invention is characterized in that the wavelength of the excitation light is in the range of 250 nm to 450 nm.
In the present invention, the wavelength of the excitation light is in the range of 250 nm to 450 nm, that is, the excitation light is light on the ultraviolet light side than visible light.
The oil property detection device according to claim 12 of the present invention comprises a polarization beam splitter that divides and outputs the detection target light into the first detection light and the second detection light. .
In the present invention, the first detection light and the second detection light are branched and extracted from the detection target light by the polarization beam splitter.
The oil property detection device according to claim 13 of the present invention is provided between the polarization beam splitter and the first light detection unit, between the polarization beam splitter and the second light detection unit, and A filter is provided that transmits light having a fluorescence wavelength and does not transmit light having the wavelength of the excitation light.
In the present invention, a filter (long-pass filter) that transmits only fluorescence without transmitting elastic scattered light (light having the wavelength of excitation light) is used.

Property detection device of oil according to claim 14 of the present invention comprises a storage unit for storing the previously obtained data for the time course of the fluorescence polarization degree and the viscosity at a particular type of oil, the analysis unit , compared to the actually measured the fluorescence polarization of the elapsed time and the data, and detecting the viscosity.
In the present invention, data on the viscosity of a specific oil type and the passage of time of the degree of depolarization of fluorescence is stored in the storage unit. The viscosity of the oil is estimated by the analysis unit with reference to this data.
The oil property detection device according to claim 15 of the present invention includes a thermometer that measures the temperature of the oil in a non-contact manner, or measures the temperature around the oil in the one region, and the analysis unit , based on the measured and detected the viscosity the temperature, and estimates the viscosity at a particular reference temperature.
In this invention, the temperature of the oil or its surroundings is measured, and the analysis unit estimates the viscosity of the oil at the reference temperature based on the estimated viscosity and the measured temperature. In order to measure the temperature around the oil, the temperature may be measured not only by a non-contact type but also by a contact type thermometer.

According to a sixteenth aspect of the present invention, there is provided the oil property detection device according to the passage of time of the fluorescence depolarization degree calculated from the first detection light and the second detection light, which is obtained in advance for each type of the oil. comprising a storage unit that stores data, the analysis unit, and estimates the kind of the oil based and actually measured the fluorescence polarization of the elapsed time and the data.
In this invention, an analysis part estimates the kind of oil using the data memorize | stored in the memory | storage part.
The oil property detection device according to claim 17 of the present invention includes a thermometer that measures the temperature of the oil in a non-contact manner or measures the temperature around the oil in the one region, and the analysis unit Is characterized in that the type is estimated based on the measured time course of the fluorescence depolarization degree , the data, and the temperature.
In the present invention, a thermometer that measures the temperature of the oil or its surroundings is used, and information on the temperature measured by this is also used for estimating the type of oil. In order to measure the temperature of the oil, a non-contact type is used, but in order to measure the temperature around the oil, not only a non-contact type but also a contact type thermometer may be used.
The oil property detection device according to claim 18 of the present invention is characterized in that a streak camera is used as the first light detection unit and the second light detection unit.
In the present invention, a streak camera capable of capturing fluorescence is used as the first light detection unit and the second light detection unit.
In the oil property detection device according to claim 19 of the present invention, the intensity of the first detection light detected by the first detection unit and the passage of time thereof, and the second detected by the second light detection unit. Intensity of detection light and its time, or the degree of depolarization of fluorescence calculated from the first detection light detected by the first detection unit and the second detection light detected by the second light detection unit It is characterized by comprising an actual measurement data storage unit for storing the time elapse.
In this invention, instead of the analysis unit, actual measurement data storage for storing the intensity of the first detection light and its time passage and the intensity of the second detection light and its time passage, or the time passage of the degree of depolarization of the fluorescence. Part is used.

Since the oil property detection method and the oil property detection device of the present invention are configured as described above, the oil existing in one region is detected and the property (viscosity and type of oil) is not contacted from a distance. Can be detected. At this time, since this property is detected based on the time lapse of the intensity ratio (fluorescence depolarization degree) of polarization components in two perpendicular directions in the fluorescence, the property can be detected with a simple device configuration.
In this case, when detecting the viscosity, by measuring the temperature of the oil, it is possible to calculate not only the currently measured viscosity but also the viscosity at the standard temperature, which is generally more useful. For oil floating on water, the oil type is often known in advance, and in this case, the time-dependent data of the above-mentioned strength ratio for this oil type, or further its temperature dependence is obtained in advance. By using this, the analysis can be performed particularly precisely and easily.
Similarly, in the case of detecting the type of oil, the data on the time course of the above-mentioned strength ratio for each oil type, or the temperature dependence thereof, is obtained in advance, and by using this, the analysis is particularly precise and accurate. It can be done easily.
At this time, the temperature of the oil may be directly measured from a remote point, but instead of directly measuring the temperature of the oil, the temperature around it can be directly measured and estimated as the temperature of the oil. In this case, temperature measurement is particularly easy.
In addition, the fluorescence of oil on water is detected in particular by matching one of the two directions with the polarization direction of the excitation light or elastic scattered light, and setting the wavelength of the excitation light within the range of 250 nm to 450 nm. Therefore, the accuracy of detection on the water can be particularly improved.
Further, by using a polarization beam splitter or a long pass filter, light to be detected by the first light detection unit (first detection light) and light to be detected by the second light detection unit (second detection light) are detected from the detection target light. It can be easily taken out.
In addition, when a streak camera is used as the first light detection unit and the second light detection unit, oil imaging (acquisition of two-dimensional shape image data) can also be performed.
When the oil property detection device includes an analysis unit and a storage unit, the oil viscosity and type can be analyzed in the device. On the other hand, when the actual measurement data storage unit is provided in place of the analysis unit and the storage unit, the entire apparatus can be reduced in size and weight, so that the configuration of the apparatus becomes easy.

It is a figure which shows the structure of the property detection apparatus of the oil which concerns on embodiment of this invention. It is a figure which shows the time passage of the intensity | strength of the polarization component of 2 directions of the fluorescence detected in the property detection apparatus of the oil which concerns on embodiment of this invention. It is a figure which shows the example of the short-term time passage of a fluorescence depolarization degree for every viscosity of oil. It is a figure shown about an example of the fluctuation | variation in the longer-term time range of the short-term time passage of a fluorescence depolarization degree. It is a figure which shows the fluctuation | variation in the long-term time range of the viscosity in mineral oil for every oil kind.

  Hereinafter, an oil property detection device (oil property detection method) according to an embodiment of the present invention will be described. The oil property detection device (oil detection device) 1 detects oil in a region (one region) where the presence of oil is to be searched. This area is, for example, a water (sea) area. In this case, the substance around the oil is water (seawater). Also in this oil detection apparatus, the fluorescence emitted from oil is detected using laser light as excitation light, as in the techniques described in Patent Documents 1 to 3. Further, similarly to the technique described in Patent Document 3, information on the polarization of fluorescence is also used. However, information relating to the properties of the oil (viscosity, etc.) can be obtained from information relating to the polarization of fluorescence, in particular from the passage of time.

  FIG. 1 is a diagram showing a configuration of the oil detection device 1. In this oil detection device 1, monochromatic laser light (excitation light) 100 emitted by a laser oscillator (light source) 10 driven by a laser power supply unit 11 is oil (oil layer) S to be detected or water around it. It is emitted towards. In FIG. 1, since the oil S is on water, the periphery of the oil S is water.

  The laser oscillator 10 is a Q-switch solid state laser, and the oscillation timing of the laser beam 100 is controlled by the timing of the Q switch by the laser power supply unit 11, and the laser beam 100 is a pulse laser beam having a pulse width of about 1 ns. The oscillation wavelength is appropriately selected as a wavelength that can be excitation light of fluorescence emitted by the oil S. Specifically, as the excitation light of the visible light fluorescence emitted by the oil S, a wavelength that is on the ultraviolet light side of the visible light is selected. In this case, when the fluorescence emitted from the oil S emitted is used, the contrast between the light emitted from the water around the oil S and the light emitted from the water can be increased, which is particularly effective in detecting the oil S. This is the same as the technique described in Patent Document 1 and the like. The wavelength of the laser beam 100 is particularly preferably in the range of 250 nm to 450 nm. The lower limit of 250 nm in this case is set with a margin in some cases where a fourth harmonic (266 nm) having a shorter wavelength than the third harmonic (355 nm) of a general YAG laser may be used. .

  Further, it is assumed that the laser beam 100 emitted here is linearly polarized and the polarization direction thereof is the vertical direction.

  The laser light 100 is irradiated onto the oil S, and the oil molecules constituting the oil S absorb the laser light 100, and then the oil molecules emit fluorescence. The wavelength of the fluorescence is longer than the wavelength of the laser beam 100. The condensing optical system 20 receives the detection target light 200 emitted from the oil S and condenses it so as to have sufficient intensity. The condensing optical system 20 may have any configuration as long as the polarization state of fluorescence detected as described later is maintained, such as a refractive optical system using a lens and a reflective optical system using a mirror. Can be used. Further, simultaneously with the oil detection device 1, for example, an imaging device according to the technique described in Patent Document 2 can be used at the same time, and the fluorescence emitted from a specific portion in the oil S can be extracted by the condensing optical system 20. The oil S emits not only the fluorescence emitted by the oil molecules but also the elastic scattered light obtained by elastically scattering the incident laser light 100 by the oil molecules. It is mixed. However, the wavelength of this elastically scattered light is equal to the wavelength of the laser beam 100. Therefore, the detection target light 200 includes fluorescence and elastic scattered light, and these wavelengths are different.

  The detection target light 200 whose intensity is increased by the condensing optical system 20 enters the polarization beam splitter 30. The polarization beam splitter 30 transmits light having a specific polarization direction component and reflects light having a polarization direction component perpendicular thereto. Here, the polarization direction (first direction) corresponding to the polarization direction (vertical direction) of the laser light 100 is set to be the latter. Therefore, among the detection target light 200, the elastic scattered light is reflected in the vertical direction by the polarization beam splitter 30, and the light component having the polarization in the direction perpendicular to the polarization beam splitter 30 (second direction) is transmitted through the polarization beam splitter 30. . When the polarization direction of the elastic scattered light changes from the oil S to the polarizing beam splitter 30, the polarizing beam splitter 30 is set so that the elastic scattered light is reflected vertically by the polarizing beam splitter 30. The Hereinafter, for convenience, the component of the detection target light 200 reflected by the polarization beam splitter 30 is referred to as an S wave component 201, and the component of the detection target light 200 transmitted through the polarization beam splitter 30 is referred to as a P wave component 202. The component of the elastic scattered light is included only in the S wave component 201 and not included in the P wave component 202, whereas, as will be described later, generally, the fluorescent component is included in both.

  The S wave component 201 is divided into two by the half mirror 31. One of the divided components (the component transmitted through the half mirror 31) is detected by the monitor light detection unit 41. The other of the divided components (the component reflected by the half mirror 31) becomes the first detection light 201A that has passed through the long-pass filter (filter) 32 that transmits light having a wavelength longer than the specific wavelength. It is detected by the detection unit 42. Further, the P wave component 202 is also detected by the second light detection unit 43 even if it becomes the second detection light 202 </ b> A that has passed through the long pass filter 32 similar to the above.

  As the light detector 41 for monitoring, the first light detector 42, and the second light detector 43, for example, a photoelectron can be used as a light detector capable of receiving pulsed light with high sensitivity and outputting a pulse corresponding to the light. A multiplier tube is used. In addition, as described above, the wavelength of the fluorescence emitted by the oil S is longer than the wavelength of the laser light 100 serving as the excitation light (the wavelength of the elastic scattered light), so the long-pass filter 32 allows the oil fluorescence to pass therethrough. It is set so that the elastic scattered light does not pass through it.

  With the above configuration, the intensity of elastic scattered light in the detection target light 200 can be monitored by the monitoring light detection unit 41. The intensity of the first detection light 201 </ b> A that is a component having the same polarization direction as that of the elastic scattered light or the laser light 100 among the fluorescence in the detection target light 200 can be monitored by the first light detection unit 42. In addition, the intensity of the second detection light 202 </ b> A that is a component having a polarization direction perpendicular to the elastic scattered light or the laser light 100 in the fluorescence in the detection target light 200 can be monitored by the second light detection unit 43. Note that the light detected by each light detection unit has a different optical path leading to each light detection unit, so in practice, the detection output of each detection unit is multiplied by a correction coefficient to obtain the light of each light detection unit. Intensity is calculated.

  The output (E signal) of the monitoring light detection unit 41, the output (FS signal) of the first light detection unit 42, and the output (FP signal) of the second light detection unit 43 are respectively connected via a preamplifier (not shown). The oscilloscope 50 can detect and display. At this time, the Q switch signal (Q-SW signal) generated by the laser power supply unit 11 or the output of the monitor detection unit 41 can be used as a trigger. The laser oscillator 10 (laser power supply unit 11), each light detection unit, and the oscilloscope 50 are controlled by the analysis / control unit 60. The analysis / control unit 60 is constituted by, for example, a personal computer.

  Here, the fluorescence is emitted after a short delay time after the oil laser absorbs the pulsed laser beam 100 from the oil S. The lifetime of this fluorescence is about 1 to 100 ns, and it is emitted in pulses within this time. For this reason, as shown in FIG. 1, the E signal, the FS signal, and the FP signal are all detected as pulse signals corresponding to the laser light 100, but FS is a component corresponding to the fluorescence emitted by the oil S. The signal and the FP signal are delayed from the E signal. Further, the E signal directly reflects the laser beam 100 itself, and, for example, if values obtained by normalizing these with the maximum value of the E signal are used as the FS signal and the FP signal, even if the intensity of the laser beam 100 is not stable, the analysis is performed. It can be performed.

  Here, although fluorescence is emitted from oil molecules, in general, the polarization direction is equal to the absorbed laser beam 100. In this case, since there is no component having a polarization direction perpendicular to the laser beam 100 in the fluorescence, the intensity ratio of the FP signal / FS signal is zero. However, in the case where the oil molecule rotates and there is a delay time until the fluorescence is emitted as described above, the oil molecule absorbs the laser light 100 until the fluorescence is emitted. Since the direction changes, the polarization direction rotates accordingly. Thereby, an FP signal is generated.

For the time change in fluorescence intensity, time variation _F S of the FS signal (t), the time variation _F P of the FP signal (t), shown schematically in FIG. Here, the solid line is the time change of the absolute value of the fluorescence intensity. As described above, F _S (t) is delayed with respect to the E signal, but for the above reason, F _P (t) is further delayed from F _S (t). An increase in F _P (t) means that oil molecules are likely to rotate during the delay time until fluorescence is emitted.

Here, F _P (t) / F _S (t) can be defined as the degree of fluorescence depolarization D. A case where D is equal to 0 corresponds to a case where there is no rotational movement of oil molecules. The characteristic of FIG. 2, since F P _(t) is rising with a delay from F _{S (t),} the time variation of D is a as shown schematically in Figure 3. Here, the absolute value of F P _(t) is the ratio of the rotating oil molecules is increased if large, the absolute value of D is also the ratio of the rotating oil molecules is increased if large. That is, in the oil S, when the oil molecules are likely to rotate, D increases. Further, when the oil molecules are likely to rotate, the rotation angle at which the oil molecules rotate during the delay time until the fluorescence is emitted becomes large. For this reason, the rise of D becomes faster.

  For this reason, when the time change of the fluorescence depolarization degree D is shown typically, it becomes as shown in FIG. As it goes from pattern A to pattern C, the oil molecules are less likely to rotate. The fact that the oil molecules are difficult to rotate means that the viscosity of the oil S is high. For this reason, the analysis / control unit (analysis unit) 60 can estimate the viscosity of the oil S from the time change of the intensity ratio (fluorescence depolarization degree D).

In addition, instead of the fluorescence depolarization degree D (F _P (t) / F _S (t)), the fluorescence anisotropy (≡ (F _s (t) −F) indicating the degree of the polarized component in the detected fluorescence. _{Even if p} (t)) / (F _s (t) + F _p (t)) is used, the fluorescence anisotropy and the fluorescence depolarization degree D correspond one-to-one, and thus the same analysis is possible. That is, in performing this analysis, fluorescence anisotropy may be used.

  Here, the viscosity is increased by, for example, (1) the molecular weight of the oil molecule being large, and (2) the temperature of the oil molecule being low. Here, the viscosity is estimated at the current temperature, but the viscosity that is actually useful data is the viscosity at a predetermined temperature (reference temperature). Here, in order to know the current temperature of the oil S, a thermometer 80 that measures the temperature of the oil S in a non-contact manner is used. The thermometer 80 is a radiation thermometer using, for example, an infrared sensor, and measures the temperature of the oil S from a location away from the oil S in a non-contact manner. Alternatively, since the temperature of the oil S can be estimated to be equal to the water temperature, a normal contact-type thermometer may be used as the thermometer 80, and thereby the water temperature may be measured at a location away from the oil S. The analysis / control unit (analysis unit) 60 can estimate the viscosity of the oil S at the reference temperature based on the measured temperature and the viscosity estimated as described above. At this time, the storage unit 70 stores various data used for the estimation (conversion), and the analysis / control unit (analysis unit) 60 can perform the conversion using the data.

  Further, FIG. 3 shows a time change on a short time scale (about several tens of ns) of D immediately after one pulse output in the laser light 100. On the other hand, various information regarding the oil S can be estimated by examining the maximum value of D in this case on a longer time scale (for example, in units of days).

  For example, NITE (National Institute of Technology and Evaluation) HP (petroleum weathering: searched on May 15, 2015) URL: http: www. nite. go. jp / nbrc / industry / bioreme 2009 / knowledge / accident / accident_1. As described in html (Internet), a change with time (weathering) occurs in the oil that has flowed from the ship to the sea. Specific examples of weathering include phenomena such as diffusion, evaporation, dissolution, dispersion, and emulsification. Here, since diffusion, dissolution, and dispersion are reflected in the spread (two-dimensional shape) of the oil S on the water, for example, information on these can be obtained by using the technique described in Patent Document 2 and the like. It can be obtained by measuring (two-dimensional shape). On the other hand, as described in the HP, when a volatile component evaporates in the oil S, a heavy component having low volatility remains, and thus the viscosity increases. In addition, when emulsification occurs with water, the oil S is also increased in viscosity because the binding of oil molecules through water increases. For this reason, the characteristic of FIG. 3 in D changes as shown in FIG. 4 with the passage of time (elapse of each day) in the long term.

  Further, as described in the above-mentioned HP, evaporation of volatile components occurs immediately after the oil spill and ends thereafter, whereas emulsification occurs after a certain period of time has passed since the spill. For this reason, the long-term time course of the viscosity when crude oil, heavy oil, or light oil that is the subject of the spill accident of particular concern is spilled is schematically as shown in FIG. Crude oil exhibits intermediate characteristics between heavy oil and light oil, but has a particularly large change in viscosity as shown in FIG.

  For this reason, if the storage unit 70 stores data acquired in advance for the characteristics shown in FIG. 5 for each type of oil, the analysis / control unit (analysis unit) 60 refers to the storage unit 70 and the data. The type of the oil S can be estimated by comparing with the actually measured value of the estimated viscosity over time. At this time, if data obtained by measuring the characteristics of FIGS. 3 to 5 for each temperature is stored in the storage unit 70, the accuracy of this estimation can be further increased using the temperature measured by the thermometer 80.

  In this way, the analysis / control unit 60 estimates the viscosity of the oil S from the time change on the short time scale in the output of each light detection unit, and from the time change of this viscosity on the long time scale, Detailed properties and types can be estimated.

  As long as the oil S that is the detection target is floating on the water, any oil can be targeted. However, as shown in FIG. It is particularly preferable to store data relating to representative mineral oil in the storage unit 70. This makes it particularly easy to deal with such accidents. In such cases, the type of oil S is often known in advance, and the viscosity is often unknown (undefined). On the other hand, if data corresponding to FIG. 3, FIG. 5 or FIG. 4 is acquired in advance for each specific oil type and stored in the storage unit 70, the analysis / control unit 60 By comparing with the measured data, the viscosity of the oil S and its state can be estimated more precisely. In this case, since the amount of data stored in the storage unit 70 can be saved, the analysis is easy and the configuration of the apparatus can be simplified.

  Actually, the temperature or water temperature of the oil S can be estimated according to the weather or the like, and in this case, the thermometer 80 is unnecessary. Further, for example, the output of the oscilloscope 50 can be stored, and the above-described analysis can be performed after the oil detection device is taken out. In this case, the analysis / control unit 80 (analysis unit for performing analysis) and the storage unit 70 are also unnecessary. In such a case, instead of these, by providing an actual measurement data storage unit that stores the output of the oscilloscope 50 (the actual output of the first light detection unit 42 and the second light detection unit 43), the analysis can be easily performed. It can be carried out. In this case, since the oil detection device itself can be made small and light, it can be particularly portable. Such a configuration is particularly effective in mounting the oil detection device on a small ship.

  In the above example, the first light detection unit 42 detects the fluorescence polarized in the first direction corresponding to the polarization direction of the laser light (excitation light) 100, and the second light detection unit 43. It was fluorescence detected in the direction perpendicular to this. However, it is clear that the same analysis can be performed even when the first direction is not exactly equal to the polarization direction. However, by making the first direction equal to the polarization direction as described above, the change in the fluorescence depolarization degree D becomes particularly significant, and thus the above configuration is particularly preferable.

  In the above example, in order to detect the first detection light 201A and the second detection light 202A, the condensing optical system 20, the first light detection unit 42, and the second light detection unit 43 (both are photomultiplier tubes). ) Etc. were used. Instead of these, it is also possible to use a streak camera capable of imaging weak light with high sensitivity and high time resolution. In this case, it is also possible to scan the laser beam 100 and image the two-dimensional shape of the oil S.

  Moreover, in said example, the oil S shall float on the water (the sea). However, as long as the oil is separated from the surrounding material in plan view, the oil can be distinguished from the surrounding material by detecting the fluorescence emitted by the oil. In addition, the properties of the oil can be detected by the above configuration. In other words, the above-described oil property detection method and oil property detection device are effective not only for examining oil on water, but also for checking the property of oil that has flowed to the surface of the earth or oil that exists in the device (eg oil tank). It is.

  The oil property detection method and the oil property detection device described above are particularly effective in ship operation management and marine environmental management. However, this oil property detection device is mounted not only on ships but also on airplanes and balloons, and can be used not only on the sea but also in environmental management of rivers and lakes. It is also effective in managing equipment that uses oil.

1 Oil detection device (oil property detection device)
10 Laser oscillator (light source)
DESCRIPTION OF SYMBOLS 11 Laser power supply part 20 Condensing optical system 30 Polarizing beam splitter 31 Half mirror 32 Long pass filter (filter)
41 light detector for monitor 42 first light detector 43 second light detector 50 oscilloscope 60 analysis / control unit (analysis unit)
70 Storage Unit 80 Thermometer 100 Laser Light (Excitation Light)
200 detection target light 201 S wave component 201A first detection light 202 P wave component 202A second detection light S oil

Claims (19)

This is an oil property detection method for detecting the property of the oil by irradiating a region on the water with excitation light and detecting fluorescence emitted after the oil present in the region absorbs the excitation light. And
As the excitation light, using light oscillated in pulses in a state linearly polarized in one direction,
Based on the time course of the degree of depolarization of fluorescence as the intensity ratio of the two polarization components in the two directions perpendicular to the fluorescence in the light to be detected, which is the light emitted by the oil by irradiating the oil with the excitation light, An oil property detection method comprising detecting the viscosity of the oil. The ambient temperature of the oil measured in the temperature of the oil measured in a non-contact, or the one region, based on the measured and detected the viscosity the temperature, estimating the viscosity at a particular reference temperature The oil property detection method according to claim 1 . The oil property detection method according to claim 1, wherein the type of oil is estimated from the passage of time of the degree of fluorescence depolarization . The time lapse data of the fluorescence depolarization degree is acquired in advance for each type of oil, and the type is estimated based on the measured time lapse of the fluorescence depolarization degree and the data. Item 4. The oil property detection method according to Item 3 . Measure the temperature of the oil in a non-contact manner, or measure the temperature around the oil in the region, and determine the type based on the measured time-lapse of the fluorescence depolarization degree , the data, and the temperature. The oil property detection method according to claim 4 , wherein estimation is performed. The oil property detection method according to any one of claims 1 to 5, wherein the oil is mineral oil. The oil property detection method according to any one of claims 1 to 6 , wherein one of the two directions corresponds to a polarization direction of the excitation light. The oil property detection method according to any one of claims 1 to 7, wherein a wavelength of the excitation light is in a range of 250 nm to 450 nm. An oil property detection device that detects the property of the oil by irradiating a region on the water with excitation light and detecting fluorescence emitted after the oil present in the region absorbs the excitation light. And
As the excitation light, a light source that emits the excitation light oscillated in a pulse form in a state linearly polarized in one direction;
The intensity of the first detection light that is a component of the fluorescence polarized in the first direction in the detection target light that is the light emitted by the oil after the oil is irradiated with the excitation light and its time passage are detected. A first light detection unit;
A second light detection unit for detecting the intensity of the second detection light that is a component of the fluorescence polarized in a second direction perpendicular to the first direction in the detection target light, and a time passage thereof;
An analysis unit that detects the viscosity of the oil based on the passage of time of the degree of depolarization of fluorescence as the intensity ratio of the first detection light and the second detection light;
An oil property detection device comprising: The oil property detection device according to claim 9 , wherein one of the first direction and the second direction corresponds to a polarization direction of the excitation light. The oil property detection device according to claim 9 or 10 , wherein a wavelength of the excitation light is in a range of 250 nm to 450 nm. Wherein the detection target light, in any one of claims 9, characterized by comprising a polarization beam splitter and outputting the branch to the first detection light and the second detection light to Claim 11 Oil property detection device. Light provided between the polarization beam splitter and the first light detection unit, and between the polarization beam splitter and the second light detection unit, respectively, transmits light having the fluorescence wavelength and emits light having the excitation light wavelength. The oil property detection device according to claim 12 , further comprising a filter that does not allow permeation of water. Comprising a storage unit that stores previously acquired data for the viscosity and the fluorescence depolarization ratio over time in a particular oil type,
The said analysis part compares the time passage of the said fluorescence depolarization degree measured with the said data, and detects the said viscosity, The any one of Claim 9 to 13 characterized by the above-mentioned. Oil property detection device. Measuring the temperature of the oil in a non-contact manner, or comprising a thermometer for measuring the temperature around the oil in the region;
Wherein the analysis unit, based on the measured and detected the viscosity the temperature, according to any one of claims 9, characterized in that for estimating the viscosity at a particular reference temperature to claim 14 Oil property detection device. A storage unit that stores data obtained over time of the degree of depolarization of fluorescence calculated from the first detection light and the second detection light, obtained in advance for each type of oil,
The analysis unit according to any one of claims 9, characterized in that for estimating the type of the oil based and actually measured the fluorescence polarization of the elapsed time and the data to claim 13 Oil property detection device. Measuring the temperature of the oil in a non-contact manner, or comprising a thermometer for measuring the temperature around the oil in the region;
The oil property detection device according to claim 16 , wherein the analysis unit estimates the type based on a measured time course of the fluorescence depolarization degree , the data, and the temperature. Wherein the first optical detector and the second optical detection unit, property detection apparatus oil according to any one of claims 9, characterized in that the streak camera is used to claim 17. The intensity of the first detection light detected by the first detection unit and the time lapse thereof, and the intensity of the second detection light detected by the second light detection unit and the lapse of time thereof,
Or
The time lapse of the degree of depolarization of fluorescence calculated from the first detection light detected by the first detection unit and the second detection light detected by the second light detection unit,
An oil property detection device according to any one of claims 9 to 13 , further comprising an actual measurement data storage unit for storing the data.