CN110726521A - Leak detection devices and transformers - Google Patents

Abstract

The present disclosure relates to a leak detection device and a transformer. The leak detection device includes a housing, an optical element, an optical transmitter, an optical receiver and a circuit board. The optical element is arranged in an installation cavity and the installation cavity is divided into first The cavity and the second cavity, the optical element has a preset refractive index; the light transmitter and the light receiver are both arranged in the first cavity, and the light transmitter is used to emit incident light perpendicular to the incident surface; when the second cavity is When the refractive index of the medium is less than the preset refractive index, the incident light can be totally reflected on the reflective surface, and can be emitted to the light receiver perpendicular to the incident surface; when the refractive index of the medium of the second cavity is greater than the preset refractive index, The incident light can be semi-reflected on the reflective surface, and the reflected light can be emitted to the light receiver perpendicular to the incident surface; the circuit board is arranged in the first cavity and connected with the light transmitter and the light receiver, and the circuit board can receive light according to the light The light intensity obtained by the detector outputs a matching light intensity signal.

Description

Leak detection devices and transformers

technical field

The present disclosure relates to the technical field of transformers, and in particular, to a leak detection device and a transformer.

Background technique

A power transformer is one of the main equipment in power plants and substations, which is used to convert a certain value of AC voltage (current) into another or several different values of voltage (current) with the same frequency. There are generally oil pillows on power transformers. The oil pillow is an oil storage device for transformers. When the volume of transformer oil expands or shrinks with the change of oil temperature, the oil pillow plays the role of oil storage and replenishment, and can Make sure the tank is full of oil. At the same time, because the oil pillow is equipped, the contact surface between the transformer and the air is reduced, and the moisture, dust and oxidized grease absorbed from the air are deposited in the depositor at the bottom of the oil pillow, thus greatly slowing down the deterioration speed of the transformer oil. .

Usually, there is an airbag in the oil pillow, and the airbag is used to isolate the transformer oil from the atmosphere, avoid direct contact, and balance the pressure in the transformer box and the outside atmosphere. When the pressure inside the box is high, the airbag is exhausted to the outside, and when the atmospheric pressure is greater than the pressure in the box, the airbag inhales, thus playing a role of breathing.

However, the airbag is prone to rupture and oil leakage due to improper operation and long use time, which leads to problems with the oil gauge of the transformer oil pillow and fails to reflect the real oil level, resulting in the wrong judgment of the oil level. If it is not found in time, there will even be major accidents such as tripping due to misjudgment of the oil level being too low.

It should be noted that the information disclosed in the above Background section is only for enhancement of understanding of the background of the present disclosure, and therefore may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

SUMMARY OF THE INVENTION

The purpose of the present disclosure is to provide a leak detection device and a transformer that can accurately determine the medium type when the medium type is known.

According to one aspect of the present disclosure, there is provided a leak detection device, the leak detection device comprising:

a casing, the casing is cylindrical and has an installation cavity;

The optical element is arranged in the installation cavity and divides the installation cavity into a first cavity and a second cavity, the casing of the second cavity is provided with an opening, and the optical element has a preset refractive index, the optical element includes an incident surface facing the first cavity and a reflective surface facing the second cavity;

The light transmitter and the light receiver are both arranged in the first cavity, and the light transmitter is used to emit incident light perpendicular to the incident surface; when the refractive index of the medium of the second cavity is smaller than the predetermined cavity When the refractive index is set, the incident light can be totally reflected on the reflective surface, and can be emitted to the light receiver perpendicular to the incident surface; when the refractive index of the medium of the second cavity is greater than the When the preset refractive index is set, the incident light can be semi-reflected on the reflective surface, and the reflected light can be emitted to the light receiver perpendicular to the incident surface;

a circuit board, arranged in the first cavity, the circuit board is connected to the light transmitter and the light receiver, and the circuit board can output matching light intensity according to the light intensity obtained by the light receiver Signal.

In an exemplary embodiment of the present disclosure, the optical element is an isosceles triangular prism.

In an exemplary embodiment of the present disclosure, the optical element is an isosceles trapezoid prism.

In an exemplary embodiment of the present disclosure, the optical element is a ball lens.

In an exemplary embodiment of the present disclosure, the preset refractive index is 1.3334˜1.3900.

In an exemplary embodiment of the present disclosure, the medium is at least one of water, air or transformer oil.

In an exemplary embodiment of the present disclosure, the light transmitter is a laser transmitter.

In an exemplary embodiment of the present disclosure, the laser transmitter includes an LED light source or an LD light source.

In an exemplary embodiment of the present disclosure, the leak detection device further includes:

One end of the signal line is connected with the circuit board, and the other end is used for connecting with the terminal, and the signal line is used for transmitting the light intensity signal.

According to another aspect of the present disclosure, a transformer is provided, and the transformer includes the leak detection device provided in any one of the above embodiments.

In the leak detection device provided by the present disclosure, when the refractive index of the medium in the second cavity is smaller than the preset refractive index, the light is emitted from the optically dense medium to the optically sparser medium, and by controlling the distance between the incident light of the light emitter and the reflective surface The angle between the two can make the exit angle of the light in the optical element larger than the critical angle of the light to the medium, so that the light is totally reflected in the optical element; when the refractive index of the medium in the second cavity is greater than the preset refractive index , the light is emitted from the optically sparser medium to the optically denser medium. Since the light cannot be totally reflected from the optically thinner medium to the optically denser medium, the light is semi-reflected in the optical element, and part of the light is projected into the medium. After the light receiver receives the light reflected by the optical element, the circuit board can output a matching light intensity signal according to the intensity of the reflected light obtained by the light receiver, and then according to the light intensity signal, the refractive index of the medium in the second cavity of the prism can be determined. greater or less than the preset refractive index of the optical element. When the medium type is known, the determination of the medium type can be realized.

In addition, the determination of the medium type is realized through the optical element, the optical transmitter, the optical receiver and the circuit board, which can reduce the difficulty of the installation and operation of the leak detection device.

It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description serve to explain the principles of the disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic diagram of a leak detection device provided by an embodiment of the present disclosure;

2 is a schematic diagram of light propagation in a light source element according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of light propagation in a light source element according to another embodiment of the present disclosure.

Description of reference numbers:

11. Optical components, 12, Optical transmitter, 13, Optical receiver, 14, Circuit board, 15, Housing, 16, Signal line.

Detailed ways

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments, however, can be embodied in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed descriptions will be omitted.

Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of an icon to another component, these terms are used in this specification only for convenience, such as according to the direction of the example described. It will be appreciated that if the device of the icon is turned upside down, the components described as "on" will become the components on "bottom". When a certain structure is "on" other structures, it may mean that a certain structure is integrally formed on other structures, or that a certain structure is "directly" arranged on other structures, or that a certain structure is "indirectly" arranged on another structure through another structure. other structures.

The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements/components/etc; the terms "include" and "have" are used to indicate an open-ended is meant to be inclusive and means that additional elements/components/etc may be present in addition to the listed elements/components/etc; the terms "first", "second" etc. are used only as labels, not Limit the number of its objects.

The applicant has found that, at present, light is usually transmitted and received through an optical fiber, and a cavity is set at the position of the probe. When immersed in oil, the optical path will be deflected due to the change in the refractive index, resulting in a change in the received light intensity. However, when there is water in the oil bag, the light intensity will also weaken, which will affect the judgment of oil leakage, and it is impossible to accurately determine whether the air bag leaks oil; The installation and operation process is complicated.

Embodiments of the present disclosure provide a leak detection device and a transformer. As shown in FIG. 1 , the leak detection device includes a housing 15 , an optical element 11 , an optical transmitter 12 , an optical receiver 13 and a circuit board 14 . The casing 15 is cylindrical and has an installation cavity; the optical element 11 is arranged in the installation cavity and the installation cavity is divided into a first cavity and a second cavity, and the casing 15 of the second cavity is provided with an opening , so that the medium can be in contact with the optical element 11, the optical element 11 has a preset refractive index, the optical element 11 includes an incident surface facing the first cavity and a reflective surface facing the second cavity; the light transmitter 12 and the light receiver 13 are set in the first cavity, and the light emitter 12 is used to emit incident light perpendicular to the incident surface; when the refractive index of the medium of the second cavity is less than the preset refractive index, the incident light can be totally reflected on the reflective surface , and can be emitted to the light receiver 13 perpendicular to the incident surface; when the refractive index of the medium of the second cavity is greater than the preset refractive index, the incident light can be semi-reflected on the reflective surface, and the reflected light can be perpendicular to the incident surface The circuit board 14 is arranged in the first cavity, and the circuit board 14 is connected to the light transmitter 12 and the light receiver 13 , and the circuit board 14 can output the matching light intensity according to the light intensity obtained by the light receiver 13 Signal.

In the leak detection device provided by the present disclosure, when the refractive index of the medium in the second cavity is smaller than the preset refractive index, the light is emitted from the optically dense medium to the optically sparser medium, and by controlling the distance between the incident light of the light emitter and the reflective surface The angle between the two can make the exit angle of the light in the optical element larger than the critical angle of the light to the medium, so that the light is totally reflected in the optical element; when the refractive index of the medium in the second cavity is greater than the preset refractive index , the light is emitted from the optically sparser medium to the optically denser medium. Since the light cannot be totally reflected from the optically thinner medium to the optically denser medium, the light is semi-reflected in the optical element, and part of the light is projected into the medium. After the light receiver receives the light reflected by the optical element, the circuit board can output a matching light intensity signal according to the intensity of the reflected light obtained by the light receiver, and then according to the light intensity signal, the refractive index of the medium in the second cavity of the prism can be determined. greater or less than the preset refractive index of the optical element. When the medium type is known, the determination of the medium type can be realized.

In addition, the determination of the medium type is realized through the optical element, the optical transmitter, the optical receiver and the circuit board, which can reduce the difficulty of the installation and operation of the leak detection device.

Wherein, the medium is at least one of water, air or transformer oil. For example, when the leak detection device is used to detect whether the airbag in the transformer oil pillow leaks oil, the medium is air or water when the airbag is intact, and the medium is oil when the airbag is leaking. Under normal circumstances, the refractive index of air is 1.0003, the reflectivity of water is 1.3333, and the refractive index of oil used for cooling and insulation in the transformer is greater than 1.3900, so that the refractive index of the optical element 11 is smaller than that of oil, greater than that of air and The refractive index of water, that is, the refractive index of the optical element 11 may be 1.3334-1.3900, for example, 1.3500, 1.3600, 1.3700, etc., which are not listed here. At the same time, the preset incident angle of the light emitter 12 on the incident surface of the optical element 11 is greater than the angle that enables the total reflection of light in the optical element 11 when the medium is water or air, so that when the second cavity is air or water , the angle of the light entering the optical element 11 on the exit surface of the optical element 11 is greater than the critical angle, and the light is totally reflected in the optical element 11 . When the second cavity is oil, when the light is emitted from the light source element to the oil, it is emitted from the optically sparser medium to the optically denser medium, the light is semi-reflected in the optical element 11, and part of the light enters the oil and is reflected to the light receiver 13 light is greatly reduced. After the light receiver 13 receives the light reflected by the optical element 11, when the medium is water, air or oil, the difference in the intensity of the light received by the light receiver 13 is relatively large, and the circuit board 14 can obtain the light according to the light received by the light receiver 13. The intensity of the reflected light outputs a matching light intensity signal, and then according to the light intensity signal, it can be determined whether the medium in the second cavity of the prism is oil, so as to realize the detection of whether the airbag in the oil pillow leaks oil.

As shown in FIG. 1 , the leak detection device further includes a signal line 16 , one end of the signal line 16 is connected to the circuit board 14 , and the other end is used to connect to the terminal, and the signal line 16 is used to transmit light intensity signals.

Specifically, the signal line 16 is used to connect the circuit board 14 to the terminal. Since the signal line 16 has high stability, the installation of the leak detection device can be made simpler, and the signal transmission between the leak detection device and the terminal can be more reliable, so as to realize the correctness of the leakage detection device. The real-time monitoring of oil leakage in the oil pillow airbag improves the reliability of the leakage detection device.

In addition, a spare signal line 16 connecting the circuit board 14 and the terminal can be provided. When the signal line 16 in use has a transmission failure, the spare signal line 16 can be activated to ensure signal transmission, thereby further improving the reliability of the leak detection device. At the same time, when the backup signal line 16 is activated, if the signal still cannot be transmitted normally, it can be judged that the fault is located on the circuit board, so as to realize the judgment of the location of the fault, improve the maintenance efficiency of the leak detection device, and reduce the maintenance cost of the leak detection device. .

As shown in FIG. 1 , the leak detection device further includes a housing 15 , which has an installation cavity, and the optical element 11 , the light transmitter 12 , the light receiver 13 and the circuit board 14 are arranged in the installation cavity. Through the setting of the housing 15, a sealed cavity is formed, and the sealed cavity forms the accommodation and installation of each component, and at the same time plays a role in preventing moisture of each component, especially to avoid condensation water on the optical element 11 or adhesion of other liquids. The problem of changing the angle of the light entering the optical element 11 due to the improved optical system also avoids the problem of failure of the circuit board due to moisture, ensures the performance and service life of each component in the leak detection device, and improves the leak detection device. reliability.

Further, the optical element 11 separates the installation cavity into a first cavity and a second cavity; the optical transmitter 12, the optical receiver 13 and the circuit board 14 are sealed within the first cavity, and the second cavity is used to accommodate medium.

The casing 15 can be cylindrical, prismatic, etc., and the casing 15 is made of stainless steel, which can prevent the casing 15 from corroding and rusting in a humid environment and ensure the reliability of the casing 15 . In addition, the housing 15 may also be made of aluminum, iron, metal alloy material or plastic material, which is not limited in the present disclosure.

As shown in FIG. 1 , the optical element 11 is a prism. As shown in FIG. 2 , the optical element 11 is, for example, an isosceles triangular prism; or, as shown in FIG. 3 , the optical element 11 is an isosceles trapezoidal prism; or, the optical element 11 can also be a lens, such as a spherical lens. The optical element 11 can be made of plastic material or glass material, and those skilled in the art can choose prisms or lenses of other shapes or materials.

Specifically, the light transmitter 12 is a laser transmitter 12 , and the use of the laser transmitter 12 can ensure the angle at which the emitted light enters the incident surface of the optical element 11 and improve the accuracy of the leak detection device.

Among them, the laser transmitter 12 includes an LED (Light Emitting Diode) light source or an LD (Semiconductor Laser) light source. When the laser transmitter 12 adopts the LED light source, it has the advantages of long life, low cost, low power consumption, small size and high reliability. When the laser transmitter 12 adopts the LD light source, it has the advantages of small beam divergence angle and strong light.

The present disclosure also provides a transformer, which includes an oil pillow, an airbag disposed in the oil pillow, and the above leak detection device disposed in the airbag. Specifically, the leak detection device is located at the bottom of the airbag. When the airbag is intact, the oil in the oil pillow will not enter the airbag. The medium of the second cavity of the optical element 11 is air or water. Since the refractive index of the optical element 11 is greater than The refractive index of air and water, the light emitted by the light transmitter 12 into the optical element 11 is totally reflected, the reflected light received by the light receiver 13 has a higher intensity, and the circuit board 14 outputs the higher intensity light obtained by the light receiver 13 Match the light intensity signal to judge whether the medium is water or air, and then determine that the airbag is intact. When the air bag is ruptured, the oil in the oil pillow enters the air bag. Since the leak detection device is located at the bottom of the air bag, the oil leaking from the air bag can directly reach the second cavity of the optical element 11. Since the refractive index of the optical element 11 is smaller than that of the oil The refractive index of the light cannot be totally reflected, so the light is semi-reflected in the optical element 11, part of the light is projected into the oil, and the intensity of the reflected light received by the light receiver 13 is relatively weak. The obtained light with a weak intensity outputs a matching light intensity signal, thereby judging that the medium is oil, and then confirming the rupture of the airbag, realizing real-time detection of the airbag in the oil pillow, and ensuring the normal operation of the transformer.

Other embodiments of the present disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or techniques in the technical field not disclosed by the present disclosure . The specification and examples are to be regarded as exemplary only, with the true scope and spirit of the disclosure being indicated by the appended claims.

Claims (10)

1. a leak detection device, is characterized in that, comprises: a casing, the casing is cylindrical and has an installation cavity; The optical element is arranged in the installation cavity and divides the installation cavity into a first cavity and a second cavity, the casing of the second cavity is provided with an opening, and the optical element has a preset refractive index, the optical element includes an incident surface facing the first cavity and a reflective surface facing the second cavity; The light transmitter and the light receiver are both arranged in the first cavity, and the light transmitter is used to emit incident light perpendicular to the incident surface; when the refractive index of the medium of the second cavity is smaller than the predetermined cavity When the refractive index is set, the incident light can be totally reflected on the reflective surface, and can be emitted to the light receiver perpendicular to the incident surface; when the refractive index of the medium of the second cavity is greater than the When the preset refractive index is set, the incident light can be semi-reflected on the reflective surface, and the reflected light can be emitted to the light receiver perpendicular to the incident surface; a circuit board, arranged in the first cavity, the circuit board is connected to the light transmitter and the light receiver, and the circuit board can output matching light intensity according to the light intensity obtained by the light receiver Signal. 2 . The leak detection device according to claim 1 , wherein the optical element is an isosceles triangular prism. 3 . 3 . The leak detection device according to claim 1 , wherein the optical element is an isosceles trapezoid prism. 4 . 4. The leak detection device according to claim 1, wherein the optical element is a ball lens. 5 . The leak detection device according to claim 1 , wherein the preset refractive index is 1.3334˜1.3900. 6 . 6 . The leak detection device according to claim 1 , wherein the medium is at least one of water, air or transformer oil. 7 . 7. The leak detection device according to claim 1, wherein the light transmitter is a laser transmitter. 8. The leak detection device according to claim 7, wherein the laser emitter comprises an LED light source or an LD light source. 9. The leak detection device according to claim 1, wherein the leak detection device further comprises: One end of the signal line is connected with the circuit board, and the other end is used for connecting with the terminal, and the signal line is used for transmitting the light intensity signal. 10. A transformer, characterized in that it comprises the leak detection device according to any one of claims 1-9.

Images