Gas detection system and detection method thereof

Abstract

The invention relates to a gas detection system and a detection method thereof.The gas detection system comprises a high-power light source, a multi-mode optical fiber, an oil pool, a high-power multi-mode optical coupler, a multi-mode optical splitter and a detection assembly, the oil pool and the multimode optical fiber form a closed light path, the oil pool is provided with a light incoming side for light incoming and a light outgoing side for light outgoing, and the transformer oil body, the high-power multimode optical coupler and the multimode optical splitter, which are used for accommodating the oil pool, are arranged on the multimode optical fiber and are respectively positioned on the light incoming side and the light outgoing side of the oil pool; the high-power multi-mode optical coupler is used for guiding the laser with the set wavelength into the multi-mode optical fiber, and the multi-mode optical splitter is used for enabling gas which is reflected by the oil pool and passes through the transformer oil body to absorb light to be detected of the laser with the set frequency to be split according to a set proportion, so that the gas concentration of part of the light to be detected is detected through the detection assembly; and the other part continuously enters the oil pool again from the multimode optical fiber.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and in particular to a gas detection system and a detection method thereof. Background Art

[0002] In the prior art, gas detection in transformer oil is mainly based on photoacoustic spectroscopy gas detection technology. The devices used for gas detection generally include oil extraction equipment, degassing equipment, gas analyzer, etc. The oil extraction equipment is used to collect oil from the transformer and return it after the detection is completed. The degassing equipment is used to separate and collect the gas in the oil by stirring, ultrasound, etc. The gas analyzer is used to analyze the collected gas through modules such as photoacoustic cells.

[0003] In the prior art, the detection of gas by gas detection devices relies on the separation of gas from oil by degassing equipment. The structural design and degassing method of the degassing equipment directly affect the efficiency and accuracy of gas detection. Summary of the invention

[0004] Based on the above description, the present invention provides a gas detection system to solve the problem that existing gas detection requires the use of degassing equipment to obtain gas in oil, which affects the efficiency and accuracy of gas detection.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: A gas detection system comprises: a high-power light source, a multimode optical fiber, an oil pool, a high-power multimode optical coupler, a multimode optical splitter and a detection component, wherein the high-power light source is used to emit a high-power laser with a set wavelength, the oil pool and the multimode optical fiber form a closed optical path and have a light input side for light input and a light output side for light output, and the oil pool is used to contain transformer oil, the high-power multimode optical coupler and the multimode optical splitter are arranged on the multimode optical fiber and are respectively located on the light input side and the light output side of the oil pool, and the high-power multimode optical coupler is used to introduce the laser with a set wavelength into the multimode optical fiber, and the multimode optical splitter is used to split the light to be detected of the laser with a set frequency reflected by the oil pool and absorbed by the gas in the transformer oil body in a set ratio, so that a part of the light to be detected detects the gas concentration through the detection component, and the other part continues to enter the oil pool from the multimode optical fiber again.

[0006] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore, the multimode optical fiber is arranged in a ring shape with an opening, and two ends of the multimode optical fiber are respectively connected to the light input side and the light output side of the oil pool.

[0007] Furthermore, the high-power multi-mode optical coupler and the multi-mode optical splitter are arranged relative to each other.

[0008] Furthermore, the spacing of the openings is used to correspond to the width of the oil pool, and the laser light entering from the light incident side of the oil pool is incident on the inner wall surface of the oil pool extending along the length direction thereof.

[0009] Furthermore, the multimode optical fibers are arranged in a circular shape in multiple layers and are stacked in a winding manner.

[0010] Furthermore, the setting ratio of the multi-mode optical splitter is 1:9, wherein one tenth of the light to be detected is used to detect the gas concentration via the detection component.

[0011] Furthermore, the high-power light source includes a laser and an optical isolator corresponding to the laser, and the optical isolator is connected to the high-power multi-mode optical coupler and is used to send a laser with a set wavelength to the high-power multi-mode optical coupler.

[0012] Furthermore, the detection component includes an electro-optical detector connected to the multi-mode optical splitter, a signal processing circuit electrically connected to the electro-optical detector, and an analysis device electrically connected to the signal processing circuit.

[0013] Furthermore, the gas detection system also includes a transformer and a pump body, and the pump body is used to pump transformer oil into the oil pool.

[0014] The present invention also provides a detection method for a gas detection system, which is applied to the gas detection system. The detection method comprises: The laser is introduced into the closed optical path through a high-power multi-mode optical coupler and enters the oil pool from the light-entering side of the oil pool; Driving the multi-mode optical splitter to perform optical splitting processing on the laser to be detected of the optical output device of the oil pool in the closed optical path to obtain partial laser light, wherein the proportion of the partial laser light to the laser light of the oil pool optical output device is less than 1; The phase shift value of the partial laser light is detected by a detection component, and the gas concentration contained in the oil pool is obtained according to the phase shift value.

[0015] Compared with the prior art, the technical solution of this application has the following beneficial technical effects: The high-power light source emits a high-power laser with a corresponding set wavelength according to the type of gas to be detected, and the high-power multi-mode optical coupler allows the high-power laser to enter the multi-mode optical fiber. Then, it enters the oil pool from the light-entering side of the oil pool, reflects multiple times on the inner wall of the oil pool, and is absorbed by the gas in the transformer oil body. The light of the corresponding frequency consumes energy, and the laser to be detected is obtained after the energy of the high-power laser is reduced. Then, it enters the multi-mode optical fiber from the light-exiting side of the oil pool, and the light to be detected is split at a set ratio by the multi-mode optical splitter. A part of the light is emitted to the detection component to obtain the concentration of the gas, and the other part continues to re-enter the oil pool through the multi-mode optical fiber, and the stable concentration reading is obtained after multiple cycles. In this way, the number of times the laser of the set frequency is reflected in the transformer oil body can be increased, the time for the laser of the set frequency to be absorbed by the gas in the transformer oil body can be extended, more energy is consumed, and the gas concentration obtained by the detection is more accurate. In this way, the gas concentration of the transformer oil body can be detected without setting up a gas extraction device, and the structure is simple, and the efficiency and accuracy are high. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a gas detection system provided by an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the optical path of the light and the oil pool; Figure 3 A schematic flow chart of a detection method for a gas detection system provided in an embodiment of the present invention.

[0017] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. High-power light source; 11. Laser; 12. Optical isolator; 2. Multimode optical fiber; 21. Opening; 3. Oil pool; 31. Light input side; 32. Light output side; 4. High-power multimode optical coupler; 5. Multimode optical splitter; 6. Detection component; 61. Electro-optical detector; 62. Signal processing circuit; 63. Analysis equipment; 7. Transformer; 8. Pump body. DETAILED DESCRIPTION

[0018] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0020] It will be appreciated that spatial relationship terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It will be appreciated that, in addition to the orientations shown in the figures, spatial relationship terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0021] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. The "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0022] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0023] Please refer to Figure 1 and Figure 2The present invention provides a gas detection system, comprising: a high-power light source 1, a multimode optical fiber 2, an oil pool 3, a high-power multimode optical coupler 4, a multimode optical splitter 5 and a detection component 6, wherein the high-power light source 1 is used to emit a high-power laser with a set wavelength, the oil pool 3 and the multimode optical fiber 2 form a closed optical path, and have a light input side 31 for inputting light and a light output side 32 for outputting light, and the oil pool 3 is used to contain the oil body of the transformer 7, the high-power multimode optical coupler 4 and the multimode optical splitter 5 are arranged The multimode optical fiber 2 is located at the light input side 31 and the light output side 32 of the oil pool 3, respectively. The high-power multimode optical coupler 4 is used to introduce the laser of the set wavelength into the multimode optical fiber 2. The multimode optical splitter 5 is used to split the light to be detected of the laser of the set frequency reflected by the oil pool 3 and absorbed by the gas in the oil body of the transformer 7 in a set ratio, so that a part of the light to be detected is detected by the detection component 6 for detecting the gas concentration, and the other part continues to enter the oil pool 3 again from the multimode optical fiber 2.

[0024] It is mainly explained that a gas concentration can be obtained each time the laser circulates out of the multi-mode beam splitter 5. By comparing multiple gas concentrations, the gas concentration readings that are closer to each other are taken to obtain the final detected gas concentration reading.

[0025] The high-power light source 1 emits a high-power laser with a corresponding set wavelength according to the type of gas to be detected, and the high-power multimode optical coupler 4 allows the high-power laser to enter the multimode optical fiber 2. Then, it enters the oil pool 3 from the light entrance side 31 of the oil pool 3, reflects multiple times on the inner wall of the oil pool 3, and is absorbed by the gas in the oil body of the transformer 7. The light of the corresponding frequency consumes energy, and the high-power laser energy is reduced to obtain the laser to be detected. Then, it enters the multimode optical fiber 2 from the light exit side 32 of the oil pool 3, and the light to be detected is split at a set ratio by the multimode optical splitter 5. A part of the light is emitted to the detection component 6 to obtain the concentration of the gas, and the other part continues to pass through the multimode optical fiber 2 and re-enters the oil pool 3, and the stable concentration reading is obtained after multiple cycles. In this way, the number of times the laser of the set frequency is reflected in the oil body of the transformer 7 can be increased, and the time for the laser of the set frequency to be absorbed by the gas in the oil body of the transformer 7 can be extended, more energy is consumed, and the gas concentration obtained by detection is more accurate. In this way, the gas concentration of the oil body of the transformer 7 can be detected without setting up a gas extraction device, with a simple structure and high efficiency and accuracy.

[0026] It should be noted that the set wavelength corresponds to the set frequency, that is, the laser light of the set wavelength can be absorbed by the gas in the oil body of the transformer 7 .

[0027] Specifically, in this embodiment, the multimode optical fiber 2 is annularly arranged with an opening 21, and the two ends of the multimode optical fiber 2 are respectively connected to the light-entering side 31 and the light-exiting side 32 of the oil pool 3. Thus, a closed optical path can be formed between the multimode optical fiber 2 and the oil pool 3, so as to facilitate the multimode optical splitter 5 to split the light so that part of the light can be recycled into the oil pool 3.

[0028] In the present invention, the shape of the oil pool 3 is not limited, as long as it can increase the number of reflections of the laser on the inner wall surface of the oil pool 3. Further, in this embodiment, the spacing of the openings 21 is used to correspond to the width of the oil pool 3, and the laser entering from the light-entering side 31 of the oil pool 3 is incident on the inner wall surface of the oil pool 3 extending along its length direction. Therefore, the laser can be reflected more times in the oil pool 3, prolonging the time of the corresponding frequency light absorbed by the oil body of the transformer 7, so that the energy is fully consumed, and the detection accuracy of the gas concentration is improved.

[0029] Furthermore, the angle between the laser light entering from the light entrance side 31 of the oil pool 3 and the wall surface of the light entrance side 31 of the oil pool 3 is ∠A, and 45°≤∠A≤70°. The laser light entering from the light entrance side 31 of the oil pool 3 can be directly incident on the inner wall surface corresponding to the light exit side 32 of the oil pool 3, thereby further increasing the number of reflections of the laser light in the oil pool 3.

[0030] In this embodiment, the high-power multimode optical coupler 4 and the multimode optical splitter 5 are arranged opposite to each other, so that the arrangement of the components is more compact and beautiful, saving space.

[0031] In this embodiment, the multimode optical fiber 2 is arranged in a circular shape with multiple layers stacked in a winding manner. The opening 21 is arranged to penetrate the multiple layers of the multimode optical fiber 2 from top to bottom. The high-power multimode optical coupler 4 simultaneously sends laser light containing a set wavelength to the multiple layers of the multimode optical fiber 2. Similarly, the multimode optical splitter 5 simultaneously performs a set ratio of light splitting on the multiple layers of the multimode optical fiber 2 to improve the detection efficiency.

[0032] In another embodiment, the high-power multimode optical coupler 4 and the multimode optical splitter 5 are respectively arranged at the top and bottom layers of the multi-layers of the multimode optical fiber 2. The laser light containing the set wavelength enters the top layer of the multimode optical fiber 2 through the high-power multimode optical coupler 4, then reflects in the oil pool 3 for energy consumption, then reflects from the light output side of the oil pool 3 to the multimode optical fiber 2, then enters the next layer of the multimode optical fiber 2, and repeats this cycle to the bottom layer of the multimode optical fiber 2, thereby further increasing the number of times the laser light is absorbed in the oil body of the transformer 7.

[0033] In the present invention, the setting ratio of the multi-mode optical splitter 5 can be adjusted. In this embodiment, the setting ratio of the multi-mode optical splitter 5 is 1:9, wherein one tenth of the light to be detected is detected by the detection component 6 to detect the gas concentration. Most of the light continues to enter the closed optical path, and a small part of the light enters the detection component 6 to obtain the gas concentration of the corresponding component.

[0034] In this embodiment, the high-power light source 1 includes a laser 11 and an optical isolator 12 corresponding to the laser 11, and the optical isolator 12 is connected to the high-power multimode optical coupler 4, and is used to send a laser with a set wavelength to the high-power multimode optical coupler 4. The laser 11 is a high-output power wide-spectrum laser 11, which is used to emit a laser with a set wavelength. The optical isolator 12 is used to send the laser with the set wavelength to the high-power multimode optical coupler 4.

[0035] In this embodiment, the detection component 6 includes an electro-optical detector 61 connected to the multi-mode optical splitter 5, a signal processing circuit 62 electrically connected to the electro-optical detector 61, and an analysis device 63 electrically connected to the signal processing circuit 62. The electro-optical detector 61 samples the high-power laser to obtain a reference electrical signal. The electro-optical detector 61 converts a portion of the incoming laser light to be detected into an electrical signal. After the electrical signal is processed by the signal processing circuit 62, the analysis device 63 obtains a phase shift value based on the characteristics of the processed electrical signal and the reference electrical signal, and obtains the concentration of the corresponding component gas in detail based on the phase shift.

[0036] It should be noted that the processing method of the signal processing circuit 62 is filtering or performing signal amplification operations, so as to facilitate the analysis device 63 to more accurately analyze the concentration of the corresponding component gas.

[0037] In this embodiment, the gas detection system further includes a transformer 7 and a pump body 8 , and the pump body 8 is used to pump the oil of the transformer 7 into the oil pool 3 .

[0038] In this embodiment, the high-power multimode optical coupler 4 is configured as a high-power multimode optical coupler. The multimode optical fiber 2 is configured as a multimode optical fiber 2, so that the number of cycles of the laser in the multimode optical fiber 2 increases, the sensitivity is improved, and the measurement accuracy is further improved.

[0039] Reference Figure 3 The present invention also proposes a detection method for a gas detection system, which is applied to the gas detection system, and the detection method comprises: S10, introducing the laser into the closed optical path through a high-power multi-mode optical coupler, and entering the oil pool from the light incident side of the oil pool; S20, driving a multi-mode optical splitter to perform optical splitting processing on the laser to be detected of the optical output device of the oil pool in the closed optical path, to obtain partial laser light, wherein the proportion of the partial laser light to the laser light of the oil pool optical output device is less than 1; S30, detecting the phase shift value of the portion of laser light through a detection component, and obtaining the gas concentration contained in the oil pool according to the phase shift value.

[0040] The laser emits a high-power laser with a set wavelength, and the electro-optical detector samples the high-power laser to obtain a reference electrical signal, and the high-power laser enters the multi-mode optical fiber loop of the ring structure through the high-power multi-mode optical coupler. The gas in the transformer oil in the oil pool absorbs the light of the corresponding frequency and consumes energy. After the laser passes through the oil pool, the energy is reduced to activate the light to be detected. The light to be detected is split by the multi-mode optical splitter in a ratio of 1:9. Nine-tenths of the light to be detected continues to enter the closed optical path, and one-tenth enters the electro-optical detector to generate an electrical signal. After the electrical signal passes through the signal processing circuit, the analysis equipment analyzes the phase offset value based on the characteristics of the electrical signal and the reference electrical signal, and then obtains the concentration of the corresponding component gas based on the phase offset value.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A gas detection system, characterized in that: include: A high-power light source, a multimode optical fiber, an oil pool, a high-power multimode optical coupler, a multimode optical splitter and a detection component, wherein the high-power light source is used to emit a high-power laser with a set wavelength, the oil pool and the multimode optical fiber form a closed optical path and have a light input side for light input and a light output side for light output, and the oil pool is used to accommodate transformer oil, the high-power multimode optical coupler and the multimode optical splitter are arranged on the multimode optical fiber and are respectively located on the light input side and the light output side of the oil pool, and the high-power multimode optical coupler is used to introduce the laser with a set wavelength into the multimode optical fiber, and the multimode optical splitter is used to split the light to be detected of the laser with a set frequency reflected by the oil pool and absorbed by the gas in the transformer oil body in a set ratio, so that a part of the light to be detected detects the gas concentration through the detection component, and the other part continues to enter the oil pool from the multimode optical fiber again.

2. The gas detection system according to claim 1, characterized in that: The multimode optical fiber is arranged in a ring shape with an opening, and two ends of the multimode optical fiber are respectively connected to the light input side and the light output side of the oil pool.

3. The gas detection system according to claim 1 or 2, characterized in that: The high-power multi-mode optical coupler and the multi-mode optical splitter are arranged opposite to each other.

4. The gas detection system according to claim 2, characterized in that: The spacing of the openings is used to correspond to the width of the oil pool, and the laser light entering from the light incident side of the oil pool is incident on the inner wall surface of the oil pool extending along the length direction thereof.

5. The gas detection system according to claim 2, characterized in that: The multimode optical fibers are arranged in a circular shape and are wound and stacked in multiple layers.

6. The gas detection system according to claim 1, characterized in that: The setting ratio of the multi-mode optical splitter is 1:9, wherein one tenth of the light to be detected is detected by the detection component to detect the gas concentration.

7. The gas detection system according to claim 1, characterized in that: The high-power light source includes a laser and an optical isolator corresponding to the laser. The optical isolator is connected to the high-power multi-mode optical coupler and is used to send laser light of a set wavelength to the high-power multi-mode optical coupler.

8. The gas detection system according to claim 1, characterized in that: The detection component includes an electro-optical detector connected to the multi-mode optical splitter, a signal processing circuit electrically connected to the electro-optical detector, and an analysis device electrically connected to the signal processing circuit.

9. The gas detection system according to claim 1, characterized in that: The gas detection system also includes a transformer and a pump body, and the pump body is used to pump transformer oil into the oil pool.

10. A detection method for a gas detection system, characterized in that: Applied to the gas detection system according to any one of claims 1 to 9, the detection method comprises: The laser is introduced into the closed optical path through a high-power multi-mode optical coupler and enters the oil pool from the light-entering side of the oil pool; Driving the multi-mode optical splitter to perform optical splitting processing on the laser to be detected of the optical output device of the oil pool in the closed optical path to obtain partial laser light, wherein the proportion of the partial laser light to the laser light of the oil pool optical output device is less than 1; The phase shift value of the partial laser light is detected by a detection component, and the gas concentration contained in the oil pool is obtained according to the phase shift value.

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