JPH0926375A - Oil leakage detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an oil leakage detecting device which can be applied to colorless oil without any influence of moisture and production of rust. SOLUTION: Since oil base components of a leakage oil considerably absorb light 9 of wavelength of 1.66-1.79μm, oil leakage can be detected at good sensibility by proving and forming a flow passage 3 of the leakage oil transmitting the light 9 of that wavelength between a light emitter 1 for emitting the light 9 and a light receiver 4 for receiving the light 9. In addition, since electric energy is unneeded on a light transmission part, a system having intrinsically safe property can be constituted and remote monitoring is made possible. Furthermore, since the light of the wavelength has a small transmission loss due to an optical fiber, the oil leakage of a long interval can be detected by connecting the light emitter and the light receiver by the optical fiber provided in the flow passage of the leakage oil and forming them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil leakage detection device for detecting oil leakage from pipelines in power plants, chemical plants and the like.

[0002]

2. Description of the Related Art Conventionally, in an oil storage tank or the like, oil leakage may occur due to deterioration of constituent materials or an accident. Not only is such an oil leak uneconomical, but it also pollutes the environment and induces disasters, so if an oil leak occurs, it should be possible to continuously monitor the oil leak so that immediate action can be taken. Was desired.

As a conventional means for continuously monitoring oil leakage, there is a means for monitoring with an infrared camera, or a method for laying a coaxial cable and measuring a change in impedance caused by the oil leaking. there were.

[0004]

In the conventional oil leak detection device, the one monitored by the infrared camera has a problem that it can deal only with colored oil such as heavy oil. In addition, a device that measures the electrical change of a coaxial cable has a problem that it is susceptible to a change in impedance due to moisture and that rust is easily generated on a metal part. The present invention seeks to solve the above problems.

[0005]

[Means for Solving the Problems]

(1) The oil leak detection device according to the invention of claim 1 is a light emitting device which emits light having a wavelength of 1.66 to 1.79 μm,
It is characterized in that it is provided with a leak oil flow path for receiving and passing the light emitted by the light emitter, and a light receiver for detecting the intensity of the light passing through the flow path.

In the above description, the light emitted by the light emitter having a wavelength of 1.66 to 1.79 μm is a light having a wavelength at which the base oil component of the leaked oil absorbs it well, and when the leaked oil is irradiated with this light. The intensity of light that has passed through the leaked oil is greatly reduced.

Therefore, the light emitting device and the light receiving device are disposed with the leaked oil passage interposed therebetween, and the light emitted by the light emitting device is constantly received by the light receiving device through the above flow passage, so that the oil changes from the intensity change. It is possible to immediately detect the occurrence of the leakage of.

(2) In the oil leakage detection device according to the second aspect of the invention, there is provided a light emitting device which emits light having a wavelength of 1.66 to 1.79 μm, and one end of which is connected to the light emitting device. It is characterized in that it is provided with an optical fiber whose part is arranged in the flow path of the leaked oil, and a light receiver connected to the other end of the optical fiber.

In the above description, when there is no leak oil in the flow path and no leak oil adheres to the optical fiber, the light emitted by the light emitter and received by one end of the optical fiber is small because the refractive index of air is smaller than that of the optical fiber. The light is received by the light receiver with almost no leakage.

However, when there is leaked oil in the flow path and it adheres to the optical fiber, the light incident on one end of the optical fiber leaks to the outside because the refractive index of the leaked oil is large.
Since it is absorbed by the leaked oil, the intensity of the light detected by the light receiver is significantly reduced.

Therefore, similarly to the invention described in claim 1, it is possible to accurately detect the oil leakage, and in the case of the present invention, the optical fiber which has a small transmission loss of the light of the above wavelength is used for the oil leakage. Since it is used for the detection unit, it is possible to detect oil leakage over a long section.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An oil leakage detection device according to an embodiment of the present invention will be described with reference to FIGS. 1 (a) and 1 (b).

In FIG. 1, 1 is 1.66 μm or more.
A light emitter (for example, InGa) that emits light with a wavelength of 79 μm or less.
2 is light 9 emitted from the light emitter 1.
Is incident on the collimator lens 3, and the collimator lens 3 emits the collimated light 9 as parallel light. A light receiver (for example, a Si photodiode or the like) that receives 9 and converts it into an electric signal and outputs the electric signal. Reference numeral 5 denotes an amplifier that amplifies and outputs the electric signal output by the light receiver 4. It is a recorder that inputs and records signals.

As shown in FIG. 1 (b), the absorption cell 3 has a porous body 7 through which oil can pass, and transmission windows 8 that are provided at both ends of the porous body 7 and that transmit light 9. It is formed by.

In the above, the light 9 emitted from the light emitter 1
Becomes parallel light 9 at the collimator lens 2, passes through the absorption cell 3, and reaches the light receiver 4. The light receiver 4 converts this into an electric signal and outputs it, and this output signal is amplified by the amplifier 5 and output to the recorder 6.

Absorption cell 3 for passing the parallel light 9
When the oil has not penetrated into this, the light 9 from the light emitter 1 reaches the light receiver 4 with almost no attenuation. On the other hand, when oil has entered the absorption cell 3, the light 9 emitted from the light emitter 1 is attenuated by the oil when passing through the absorption cell 3, and as a result, the light 9 is transmitted to the light receiver 4. The intensity of the light 9 that arrives is significantly reduced.

Therefore, by monitoring the output from the light receiver 4 with the recorder 6, it is possible to detect oil leakage. An optical fiber or the like may be used as a means for transmitting the light 9 between the light emitter 1 and the absorption cell 3 and between the absorption cell 3 and the light receiver 4.

Next, an oil leakage detection device according to another embodiment of the present invention will be described with reference to FIG. In the present embodiment shown in FIG. 2, an optical fiber is used for the oil detecting portion.

In FIG. 2, reference numeral 11 denotes a light emitter for emitting light 17 having a wavelength of 1.66 μm or more and 1.79 μm or less.
Reference numeral 2 denotes a collimator lens that receives the light 17 emitted from the light emitter 11 and emits the light 17 as parallel light, and 13 transmits the light emitted from the collimator lens 12 and a part of the collimator lens is disposed in the leakage oil flow path. Optical fiber (quartz glass optical fiber etc.), 14 is a light receiver for receiving the light emitted from the optical fiber 13 and converting it into an electric signal for output, and 15 is for amplifying and outputting the electric signal output by the light receiver 14. An amplifier 16 is a recorder for inputting and recording the electric signal output from the amplifier 15.

In the above, the light 1 emitted from the light emitter 11
The collimator lens 2 forms parallel light 7 which is transmitted through the optical fiber 13 and reaches the light receiver 14. The light receiver 14 converts this into an electric signal and outputs it, and this output signal is amplified by the amplifier 15 and output to the recorder 16.

When the optical fiber 13 is surrounded by air, the refractive index of air (about 1.00) is considerably smaller than the refractive index of the optical fiber (about 1.45 in a silica glass system). The light transmitted through is repeatedly totally reflected at the boundary of air surrounding the optical fiber 13 and hardly leaks to the outside.

However, when oil adheres to the optical fiber 13, the refractive index of oil is high (about 1.43 to 1.46).
Therefore, the transmitted light leaks to the outside and the intensity of the backscattered light decreases. Particularly in the present embodiment, the wavelength of the light transmitted through the optical fiber 13 is 1.66 μm or more and 1.79.
Since the thickness is set to less than or equal to μm, which corresponds to the molecular absorption of the base oil component of the oil, the transmitted light is largely absorbed, and the intensity of the backscattered light is greatly reduced. Therefore, the recorder 16 displays the output from the light receiver 14, and by monitoring this, it is possible to detect oil leakage.

[0023]

The oil leak detection device of the present invention has a wavelength of 1.6.
The base oil component of the leaked oil has the above-mentioned wavelength because the flow path of the leaked oil that transmits the light is provided between the light emitter and the light receiver that emits and receives the light of 6 to 1.79 μm. Since it absorbs light well, it is possible to detect oil leaks with good sensitivity, and because electrical energy is not required in the optical transmission part, a system with intrinsically safe explosion-proof can be configured and remote monitoring is possible. Is possible.

Further, since the light emitter and the light receiver are connected by the optical fiber arranged in the flow path of the leaked oil, the light of the above wavelength has a small transmission loss by the optical fiber. It is possible to detect oil leakage in a long section.

[Brief description of drawings]

FIG. 1 is an explanatory view of an oil leakage detection device according to an embodiment of the present invention, (a) is an overall view, and (b) is a detailed view of an absorption cell.

FIG. 2 is an explanatory diagram of an oil leak detection device according to another embodiment of the present invention.

[Explanation of symbols]

 1 Light emitter 2 Collimator lens 3 Absorption cell 4 Light receiver 5 Amplifier 6 Recorder 7 Porous body 8 Transmission window 9 Light 11 Light emitter 12 Collimator lens 13 Optical fiber 14 Light receiver 15 Amplifier 16 Recorder 17 Light

Claims (2)

[Claims] 1. A light-emitting device that emits light having a wavelength of 1.66 to 1.79 μm, a flow path of leaked oil that receives and passes the light emitted by the light-emitting device, and light that has passed through the flow path. And an optical receiver for detecting the intensity of the oil leak detection device. 2. A light-emitting device which emits light having a wavelength of 1.66 to 1.79 μm, an optical fiber whose one end is coupled to the light-emitting device, and a part of which is arranged in a leak oil flow path. An oil leak detection device comprising: a light receiver coupled to the other end of the optical fiber.