Portable detector of alcohol deterioration products of insulating oil in oil filled power facility

Abstract

The present invention relates to a portable detection device for alcohol degradation products in insulating oil of an incoming power plant. In one embodiment, the detection device comprises: a sample container in which an insulating oil sample is received; a sample holder in which the sample container is mounted; a gas pump for injecting a carrier gas into the sample container; and a sensor unit for measuring the concentration of alcohol degradation products in the insulating oil sample. The sample holder comprises a mounting part in which the sample container is mounted, a heating means for heating the insulating oil sample, and an ultrasonic application part provided at the bottom of the mounting part for applying ultrasonic waves during heating. When the insulating oil sample is heated by applying ultrasonic waves, it generates a volatile gas containing alcohol degradation products, and the volatile gas is transported to the sensor unit by the carrier gas to measure the concentration of the alcohol degradation products.

Description

Technology Field

[0001] The present invention relates to a portable detection device for alcohol degradation products in insulating oil of an oil-filled power facility. More specifically, the present invention relates to a portable detection device for alcohol degradation products in environmentally friendly ester insulating oil of an oil-filled power facility. Background Technology

[0003] Representative insulating materials for oil-filled power equipment include insulating oil and insulating paper. Generally, mineral oil, vegetable insulating oil, and synthetic ester insulating oil are used as insulating oils; however, for oil-filled equipment to which the device of the present invention is applied, an eco-friendly ester insulating oil containing vegetable insulating oil and synthetic ester insulating oil is used. Furthermore, kraft paper is used as insulating paper. Kraft consists of a cellulose fiber structure extracted from wood pulp raw materials. These fibers are composed of bundles of cellulose molecules of different lengths. They form a molecular bonding structure based on OH functional groups and carbon. Cellulose itself is a linear polymer of glucose molecules, bonded through glycosidic molecular bands. The mechanism of such cellulose degradation is complex and depends on the operating environment. When insulating paper is used as an insulator for oil-filled power equipment, degradation proceeds most significantly due to thermal factors.

[0004] Due to such thermal degradation, the condition of the insulating paper changes, and various test methods are performed to analyze these characteristics. Representative analysis methods include tensile strength, degree of polymerization, furan compound measurement, and methanol measurement.

[0005] First, tensile strength measures the mechanical strength of insulation paper by determining the maximum stress at which the insulation paper specimen breaks. To improve measurement accuracy, measurements must be taken on unfolded or uncrumpled sections. Additionally, while the tensile strength test method allows for the direct measurement of insulation paper degradation, it has the disadvantage of requiring a large number of specimens per test. Generally, tensile strength decreases as the insulation paper deteriorates.

[0006] The next analytical method for measuring insulation degradation is the degree of polymerization. Measuring the degree of polymerization compensates for the disadvantage of tensile strength, which is the need for a large sample volume. Since the degree of polymerization has a high correlation with tensile strength, it is replacing the tensile strength analysis method. The degree of polymerization can be obtained by measuring the viscosity of the insulation paper. To measure the viscosity of insulation paper, the insulating oil impregnated within the paper is removed, fluff is formed, and the paper is dissolved in a designated solvent. Then, the viscosity of the mixed solution containing the dissolved insulation paper is measured. Similar to tensile strength, the analysis of the degree of polymerization of insulation paper has the advantage of directly analyzing the condition of the insulation paper. However, this analysis must be performed by skilled experimenters and operators. It also presents the problem that analyzing a single sample requires 2 to 4 days or more. Furthermore, since both tensile strength and the degree of polymerization are methods that directly analyze the insulation paper, insulation paper must be sampled from power facilities because the necessary insulation paper is required for analysis. However, there is a difficulty in that the equipment must be dismantled and disassembled to sample insulation paper from oil-filled power facilities in operation.

[0007] To compensate for these drawbacks, analyzing degradation products in insulating oil is an indirect method of analyzing the degradation state of insulating paper. This method utilizes the fact that products generated by the degradation of insulating paper are dissolved in the insulating oil; by sampling the insulating oil and detecting or analyzing the degradation products within it, the condition of the insulating paper can be analyzed without directly sampling the insulating paper.

[0008] Representative degradation products of eco-friendly ester insulating oils are furfural, a furan compound, and methanol, an alcohol. The cellulose in insulating paper degrades due to factors such as oxygen, heat, and moisture, causing glucose bonds to break and glucose decomposition products to exist within the insulating paper. Under the influence of moisture and acid, glucose generated undergoes hydrolysis and condensation reactions of glucose monomers to produce furfural, a furan compound. Furfural is dissolved in insulating oil. Methods for analyzing furfural in insulating oil include high-performance liquid chromatography (HPLC), a precise analysis method, and simple analysis instruments.

[0009] Methanol, another degradation product, was detected in an accelerated degradation test of insulation paper in eco-friendly ester insulating oil conducted by Jalbert et al. of Hydro Quebec. It was confirmed that methanol was present in 94% of the insulating oils of transformers using eco-friendly ester insulating oil during operation, confirming the potential for monitoring insulation paper degradation under normal transformer operating conditions. Furthermore, it was confirmed that methanol in eco-friendly ester insulating oil is detected from the early stages of insulation paper degradation and has a linear relationship with the degree of polymerization, suggesting that it can be utilized as an evaluation factor for early insulation paper degradation. In other words, there is a strong correlation between methanol and the decomposition of 1,4-β-glycosidic bonds that occurs when cellulose, a major component of insulation paper in eco-friendly ester insulating oil, degrades.

[0010] Gas chromatography-mass spectrometers (GC / MS) equipped with a headspace are used to detect lower alcohols, such as methanol and ethanol, in eco-friendly ester insulating oils. The headspace / GC / MS system heats the eco-friendly ester insulating oil to a specific temperature to elute dissolved gases or volatile organic compounds (VOCs), which are then injected into the GC for analysis. Inside the GC, a long, narrow column is present; as the injected mixed sample passes through the column, it is separated into individual components based on adsorption or molecular size with the materials packed or coated within the column. The separated components then reach the mass spectrometer detector in sequence, allowing for qualitative and quantitative analysis. This method is a precise analytical technique capable of measuring very low concentrations ranging from a few ppb to ppm. However, the analytical equipment is expensive, can only be operated in a laboratory, and requires specialized training and skilled experts to perform accurate analyses using the equipment.

[0011] To date, there is no portable device available to analyze alcohols, such as methanol and ethanol, present in eco-friendly ester insulating oils. However, various sensors for analyzing alcohol do exist. A representative example of sensor application is portable breathalyzers. Generally, sensors for measuring ethanol, a type of alcohol, are classified into IR (InfraRed), electrochemical, and semiconductor types based on measurement accuracy and durability. In some U.S. states and Europe, police use IR breathalyzers as legal evidence, while in Korea, police use breathalyzers utilizing electrochemical sensors for legal evidence during drunk driving checks.

[0012] In the case of semiconductor sensors, alcohol components adsorb onto and react with the surface of a metal oxide heated to a high temperature. This reaction alters the oxygen content on the metal oxide surface, changing the potential barrier and consequently altering electrical conductivity, thereby generating an electrical signal. In other words, the metal oxide reacts with alcohol, loses oxygen, and is reduced to become metallic, which facilitates the flow of electricity and alters the electrical signal. Semiconductor sensors have the advantages of simple detection circuit configuration, ease of fabrication, the possibility of mass production, and the ability to detect various gases. However, they have the disadvantage of being difficult to accurately detect gas concentrations due to interference caused by various gases and substances other than the target.

[0013] Electrochemical gas sensors detect changes in current values ​​generated by oxidation-reduction reactions at the anode and cathode as a target gas, including alcohol, reacts. This sensor consists of two electrodes where the reaction takes place, an electrolyte through which hydrogen ions move, and a separator that protects the sensor interior and allows the external target gas to move to the electrodes. Electrochemical sensors are classified into galvanic cell and potentiostatic types. The reaction principle involves hydrogen ions generated by the reaction at the electrodes moving through the electrolyte, while electrons move through an external circuit. The sensor detects the electrical signal resulting from the movement of electrons through the external circuit. Electrochemical gas sensors possess advantages such as excellent sensitivity, good stability, small size, and high selectivity. However, they have the disadvantage of a limited shelf life of 6 months to 1 year. This significantly impacts performance due to sensor aging. Additionally, while gas selectivity is improving, the sensor is still subject to interference from other gases.

[0014] Optical gas sensors measure the light absorption of gas molecules and convert it into concentration; the InfraRed (IR) method is the most widely used in the market. The IR method measures gas concentration by utilizing an infrared bandpass filter located between an infrared light source and an infrared sensor to determine the reduction in electrical signals based on the degree of infrared light absorption by the specific gas. Compared to electrochemical sensors, IR gas sensors offer advantages such as high measurement precision and low power consumption, and they are primarily used for carbon dioxide measurement by applying a 4.26㎛ bandpass filter. However, due to slow response times, large size, and high cost, it has been difficult to operate them directly in the field while being portable.

[0015] The background technology related to the present invention is disclosed in Korean Registered Patent Publication No. 10-2150428 (published September 1, 2020; Title of Invention: Defect Diagnosis Device Using Oil-Dissolved Gas Generation Pattern of Transformer). The problem to be solved

[0017] One objective of the present invention is to provide a portable detection device for alcohol degradation products in insulating oil that can be analyzed in a short time at the site due to its excellent portability, rapid detection, and ease of operation.

[0018] Another objective of the present invention is to provide a portable detection device for alcohol degradation products in insulating oil that is inexpensive to analyze and highly economical.

[0019] Another objective of the present invention is to provide a portable detection device for alcohol degradation products in insulating oil, which has excellent accuracy and reliability in the detection results of alcohol degradation products.

[0020] Another objective of the present invention is to provide a method for detecting alcohol degradation products in insulating oil using the portable detection device. means of solving the problem

[0022] One aspect of the present invention relates to a portable detection device for alcohol degradation products in insulating oil. In one embodiment, the detection device comprises: a sample container in which an insulating oil sample is received; a sample holder in which the sample container is mounted; a gas pump for injecting a carrier gas into the sample container; and a sensor unit for measuring the concentration of alcohol degradation products in the insulating oil sample. The sample holder comprises a mounting part in which the sample container is mounted, a heating means for heating the insulating oil sample, and an ultrasonic application part provided at the bottom of the mounting part for applying ultrasonic waves when heating. When the insulating oil sample is heated by applying ultrasonic waves, it generates a volatile gas containing alcohol degradation products, and the volatile gas is transported to the sensor unit by the carrier gas to measure the concentration of the alcohol degradation products.

[0023] In one embodiment, one side and the other side of the upper portion of the sample container are respectively connected to a supply pipe and a transfer pipe, and the gas pump can inject a carrier gas into the sample container through the supply pipe and transfer the volatile gas to the sensor unit through the transfer pipe.

[0024] In one embodiment, the portable detection device may further include a vapor filter provided upstream of the sensor unit to filter the vapor in which insulating oil is vaporized in the volatile gas of the transfer pipe.

[0025] In one embodiment, the oil vapor filter may include one or more of cellulose acetate, polyamide, mixed cellulose ester (MCE), polyethersulfone, and polyvinylidene difluoride (PVDF).

[0026] In one embodiment, the portable detection device may further include an output unit electrically connected to the sensor unit and outputting the concentration measured from the sensor unit.

[0027] In one embodiment, the sensor part is maintained at 200 to 250°C, and the outer wall of the sensor part may have an insulating layer formed thereon.

[0028] In one embodiment, the insulating layer may include one or more of alumina (Al2O3) and zirconia (ZrO2).

[0029] In one embodiment, the insulating oil sample is heated to 75 to 90°C during heating, and ultrasonic waves with a frequency of 20 kHz to 60 kHz may be applied.

[0030] In one embodiment, the alcohol degradation product may include one or more of methanol and ethanol.

[0031] In one embodiment, the carrier gas may include one or more of oxygen, nitrogen, and argon.

[0032] Another aspect of the present invention relates to a method for detecting alcohol degradation products in insulating oil using a portable detection device. In one embodiment, the detection method comprises a sample container in which an insulating oil sample is received, a sample holder in which the sample container is mounted, a gas pump for injecting a carrier gas into the sample container, and a sensor unit for measuring the concentration of alcohol degradation products in the insulating oil sample, wherein the sample holder comprises a mounting part in which the sample container is mounted, a heating means for heating the insulating oil sample, and an ultrasonic application part provided below the mounting part for applying ultrasonic waves during heating, and comprises the steps of: applying ultrasonic waves to the insulating oil sample and heating it to generate a volatile gas containing alcohol degradation products; and transferring the volatile gas to the sensor unit by the carrier gas to measure the concentration of alcohol degradation products.

[0033] In one embodiment, one side and the other side of the upper portion of the sample container are respectively connected to a supply pipe and a transfer pipe, and the gas pump can inject a carrier gas into the sample container through the supply pipe and transfer the volatile gas to the sensor unit through the transfer pipe.

[0034] In one embodiment, the portable detection device may further include a vapor filter provided upstream of the sensor unit to filter the vapor in which insulating oil is vaporized in the volatile gas of the transfer pipe.

[0035] In one embodiment, after the step of measuring the concentration of the alcohol degradation product, the method may further include the step of outputting the concentration of the alcohol degradation product through an output unit electrically connected to the sensor unit.

[0036] In one embodiment, the sensor part is maintained at 200 to 250°C, and the outer wall of the sensor part may have an insulating layer formed thereon.

[0037] In one embodiment, the insulating oil sample is heated to 75 to 90°C during heating, and ultrasonic waves with a frequency of 20 kHz to 60 kHz may be applied.

[0038] In one embodiment, the alcohol degradation product may include one or more of methanol and ethanol.

[0039] In one embodiment, the carrier gas may include one or more of oxygen, nitrogen, and argon. Effects of the invention

[0041] When the portable detection device for alcohol degradation products in insulating oil and the detection method using the same according to the present invention are applied, portability, rapid detection, and operational convenience are excellent, allowing for analysis to be performed in a short time at the site, and the analysis cost is low and economic efficiency is excellent, and the accuracy and reliability of the detection results of alcohol degradation products in insulating oil can be excellent. Brief explanation of the drawing

[0043] FIG. 1 is a cross-sectional view of a detection device according to one embodiment of the present invention. FIG. 2 shows a plan view of a detection device according to one embodiment of the present invention. FIG. 3 shows a sample container according to one embodiment of the present invention. FIG. 4 shows a detection method according to one embodiment of the present invention. FIG. 5 schematically illustrates a detection method according to one embodiment of the present invention. Specific details for implementing the invention

[0044] In describing the present invention, if it is determined that a detailed description of related known technologies or configurations could unnecessarily obscure the essence of the invention, such detailed description will be omitted.

[0045] Furthermore, the terms described below are defined in consideration of their functions in the present invention; since these may vary depending on the intentions or practices of the user or operator, their definitions should be based on the content throughout this specification describing the present invention.

[0047] The present invention relates to a device for detecting alcoholic degradation products, such as methanol and ethanol, among the degradation products of insulating oil and insulating paper that occur due to partial discharge, overheating, or abnormal phenomena occurring inside an oil-filled power facility where the eco-friendly ester insulating oil and insulating paper of the present invention are used as insulating materials.

[0048] Eco-friendly ester insulating oil and insulating paper account for the largest portion of the insulating media used in eco-friendly ester-oiled power facilities. Among these, the lifespan of the insulating paper is considered to determine the lifespan of the power facility. As insulating paper within eco-friendly ester insulating oil deteriorates, degradation products such as furan compounds like furfural and alcohols like methanol and ethanol are generated. Among these degradation products, methanol and ethanol are substances that appear in the early stages of insulating paper degradation. The detection of these alcoholic degradation products enables the identification of the initial degradation state of power facilities using eco-friendly ester insulating oil and can provide crucial information for operation, management, and prompt future response. Currently, the method used to detect alcoholic degradation products in eco-friendly ester insulating oil utilizes headspace GC. While this analytical method offers the advantage of precision, it is difficult to operate in the field because the equipment is expensive, operating conditions are stringent, and it requires skilled personnel. Therefore, there is a need for an analytical device that enables easy, simple, and accurate measurements in the field. The present invention relates to a detection device capable of conveniently and rapidly measuring alcoholic degradation products in eco-friendly ester insulating oil at the site, and a detection method using the same.

[0050] Portable detection device for alcohol degradation products in insulating oil

[0051] One aspect of the present invention relates to a portable detection device for alcohol degradation products in insulating oil (hereinafter referred to as the portable detection device or detection device). FIG. 1 is a cross-sectional view of a detection device according to one embodiment of the present invention, and FIG. 2 is a plan view of said detection device.

[0052] Referring to FIGS. 1 and 2 above, the detection device (1000) includes: a sample container (100) in which an insulating oil sample is stored; a sample holder (110) on which the sample container (100) is mounted; a gas pump (200) for injecting a carrier gas into the sample container (100); and a sensor unit (300) for measuring the concentration of alcohol degradation products in the insulating oil sample.

[0053] For example, the above insulating oil may include ester insulating oil.

[0054] Referring to FIGS. 1 and 2 above, the sample holder (110) includes a mounting portion (111) on which a sample container (100) is mounted, a heating means (112) for heating the insulating oil sample, and an ultrasonic application portion (113) provided below the mounting portion (111) for applying ultrasonic waves when heating.

[0055] Referring to FIGS. 1 and FIGS. 2 above, the detection device (1000) may further include a housing (10) in which a sample container (100), a sample holder (110), a gas pump (200), and a sensor unit (300) are accommodated.

[0056] In one embodiment, the housing (10) may be provided with a cover (12) that can be opened and closed at a position corresponding to the upper surface of the sample holder (110) so that the sample container (100) can be detachably attached.

[0057] In one embodiment, the mounting portion of the sample holder may have a shape corresponding to the sample container, and may further be provided with a cover (not shown) that is open at the top or openable and closable. For example, the sample container may be in the shape of a cylinder.

[0058] For example, a heating means (112) may be formed along the side of the mounting portion (111). The heating means may include, but is not limited to, a heating wire.

[0059] In one embodiment, when the insulating oil sample is heated by applying ultrasound in an ultrasound application unit, it generates a volatile gas containing an alcohol degradation product, and the volatile gas is transported to a sensor unit by the carrier gas so that the concentration of the alcohol degradation product is measured.

[0060] As the sample container containing the insulating oil sample is heated and ultrasonic waves are applied, methanol and ethanol in the insulating oil sample may volatilize and leach out to the top of the sample container.

[0061] In one embodiment, the volatile gas may include an alcohol degradation product and a vaporized insulating oil. In one embodiment, the alcohol degradation product may include one or more of methanol and ethanol.

[0062] In one embodiment, the carrier gas may include one or more of oxygen (O2), nitrogen (N2), and argon (Ar). For example, it may include air.

[0063] FIG. 3 shows a sample container according to one embodiment of the present invention. Referring to FIG. 3, the sample container (100) contains an insulating oil sample (S), and a first hole (101) and a second hole (102) may be formed on one side and the other side of the upper part of the sample container (100). Referring to FIG. 1 to FIG. 3, the first hole (101) and the second hole (102) are each connected to a supply pipe (210) and a transfer pipe (310), respectively. The supply pipe (210) is connected to a gas pump (200) to supply carrier gas into the sample container (100), and the transfer pipe (310) is connected to a sensor unit (300) to transfer volatile gas so that the concentration of alcohol degradation products can be measured.

[0064] In one embodiment, the gas pump can inject a carrier gas into a sample container through the supply pipe and transfer the volatile gas to a sensor unit through the transfer pipe.

[0065] For example, the supply pipe and the transfer pipe may each be in the form of a hollow needle or a hollow pipe.

[0066] For example, the supply pipe and the transfer pipe may be formed at a height exceeding the storage height of the insulating oil sample so as not to come into contact with the insulating oil sample. Under the above conditions, the reliability and accuracy of the detection results of alcohol degradation products in the insulating oil may be excellent.

[0067] In one embodiment, the insulating oil sample may be heated to 75 to 90°C using a heating means during heating, and ultrasonic waves with a frequency of 20 kHz to 60 kHz may be applied using an ultrasonic application unit. When heated under these conditions, alcohol degradation products (including methanol and ethanol) in the insulating oil sample are easily vaporized, and when heated while applying the ultrasonic waves, the vaporization rate of the alcohol degradation products in the insulating oil sample is accelerated, enabling rapid analysis and excellent accuracy and reliability of the analysis results. For example, the insulating oil sample may be heated to 80 to 90°C during heating, and ultrasonic waves with a frequency of 30 kHz to 50 kHz may be applied.

[0068] In one embodiment, the above ultrasound can be applied under conditions of a frequency of 20 to 60 kHz and an amplitude of 0.1 to 30 μm. When ultrasound is applied under the above frequency and amplitude conditions, the vaporization rate of alcohol degradation products in the insulating oil sample is accelerated, enabling rapid analysis and excellent accuracy and reliability of the analysis results.

[0069] Referring to FIGS. 1 and 2 above, the detection device (1000) may further include a vapor filter (320) provided upstream of the sensor unit (300) to filter the vaporized insulating oil vapor in the volatile gas of the transfer pipe (310). When the vapor filter (320) is included, the vapor of the volatile gas can be easily filtered, and the reliability and accuracy of the detection result of alcohol degradation products in the insulating oil can be excellent.

[0070] In one embodiment, the vapor filter may include a hydrophilic material. For example, the vapor filter may include one or more of cellulose acetate, polyamide (nylon), mixed cellulose ester (MCE), polyethersulfone (PES), and polyvinylidene difluoride (PVDF).

[0071] Referring to FIGS. 1 and FIGS. 2 above, the detection device (1000) may further include an output unit (400) that is electrically connected to a sensor unit (300) and outputs a concentration measured from the sensor unit (300).

[0072] In one embodiment, the sensor part (300) is maintained at 200~250℃, and an insulating layer may be formed on the outer wall (outer surface) of the sensor part (300). Under the above temperature conditions, the reliability and accuracy of the detection results of alcohol degradation products in insulating oil are excellent, and when the insulating layer is formed, the temperature of the sensor part can be easily maintained, so the reliability and accuracy of the detection results of alcohol degradation products in insulating oil can be excellent.

[0073] The above insulating layer is made of a material that is not reactive with the alcohol degradation product and has no adsorption capacity, so it can react on the sensor surface without alcohol loss in the volatile gas flowing into the sensor part.

[0074] In one embodiment, the insulating layer may include one or more of alumina (Al2O3) and zirconia (ZrO2). When the insulating layer is applied, the temperature of the sensor part can be easily maintained, so the reliability and accuracy of the detection results of alcohol degradation products in insulating oil can be excellent.

[0075] In one embodiment, alcohol adsorbed on the surface of the sensor unit reacts with oxygen on the surface of the sensor unit to be converted into a concentration of CO or CO2, and the surface of the sensor unit is reduced, causing a decrease in resistance. The concentration can be detected based on the amount of change in this electrical resistance signal. The total sum of the concentrations of the alcohol (one or more of methanol and ethanol) degradation products detected and measured by the sensor unit can be displayed on the output unit. The output unit can display the concentration of the alcohol degradation products through a display.

[0077] Method for detecting alcohol degradation products in insulating oil using a portable detection device

[0078] Another aspect of the present invention relates to a method for detecting alcohol degradation products in insulating oil using a portable detection device (hereinafter, detection method).

[0079] In one embodiment, the detection method comprises a sample container in which an insulating oil sample is received, a sample holder in which the sample container is mounted, a gas pump for injecting a carrier gas into the sample container, and a sensor unit for measuring the concentration of alcohol degradation products in the insulating oil sample. The sample holder is implemented using a detection device comprising a mounting part in which the sample container is mounted, a heating means for heating the insulating oil sample, and an ultrasonic application part provided below the mounting part for applying ultrasonic waves during heating. The detection device may be the same as that described above.

[0080] FIG. 4 illustrates a detection method according to one embodiment of the present invention. Referring to FIG. 4, the detection method comprises: (S10) a step of heating an insulating oil sample while applying ultrasound to generate a volatile gas containing an alcohol degradation product; and (S20) a step of transporting the volatile gas to a sensor unit by means of a carrier gas to measure the concentration of the alcohol degradation product.

[0081] FIG. 5 schematically illustrates a detection method according to one embodiment of the present invention. As shown in FIG. 5(a), an insulating oil sample can be collected from an inflow-type power facility and stored in a sample container. Additionally, the inside of the sample container may contain an insulating oil sample and an alcohol degradation product component generated from the degradation of insulating oil and insulating paper inside the inflow-type power facility.

[0082] As shown in FIG. 5(b) above, the sample container is mounted on the sample holder of the detection device, and as shown in FIG. 5(c), one side and the other side of the upper part of the sample container are connected to a supply pipe and a transfer pipe, respectively, and the gas pump can inject carrier gas into the sample container through the supply pipe and transfer the volatile gas to the sensor part through the transfer pipe.

[0083] In one embodiment, the portable detection device may further include a vapor filter provided upstream of the sensor unit to filter the vapor in which insulating oil is vaporized in the volatile gas of the transfer pipe.

[0084] In one embodiment, the sensor part is maintained at 200 to 250°C, and an insulating layer may be formed on the outer wall of the sensor part. Under the above temperature conditions, the reliability and accuracy of the detection results of alcohol degradation products in insulating oil are excellent, and when the insulating layer is formed, the temperature of the sensor part can be easily maintained, so the reliability and accuracy of the detection results of alcohol degradation products in insulating oil can be excellent.

[0085] As shown in FIG. 5(d) above, when heating the insulating oil sample by applying ultrasound, the insulating oil sample may vaporize, and volatile gas containing alcohol (including methanol and ethanol) degradation products and oil vapor (insulating oil vapor) may be generated. Then, as shown in FIG. 5(e) above, the gas pump can inject a carrier gas into the sample container through the supply pipe and transfer the volatile gas to the sensor unit through the transfer pipe.

[0086] In one embodiment, the insulating oil sample may be heated to 75 to 90°C during heating, and ultrasonic waves with a frequency of 20 kHz to 60 kHz may be applied. When heated under these conditions, alcohol degradation products (including methanol and ethanol) in the insulating oil sample are easily vaporized, and when heated while applying the ultrasonic waves, the vaporization rate of the alcohol degradation products in the insulating oil sample is accelerated, enabling rapid analysis and excellent accuracy and reliability of the analysis results. For example, the insulating oil sample may be heated to 80 to 90°C during heating, and ultrasonic waves with a frequency of 30 kHz to 50 kHz may be applied.

[0087] In one embodiment, the above ultrasound can be applied under conditions of a frequency of 20 to 60 kHz and an amplitude of 0.1 to 30 μm. When ultrasound is applied under the above frequency and amplitude conditions, the vaporization rate of alcohol degradation products in the insulating oil sample is accelerated, enabling rapid analysis and excellent accuracy and reliability of the analysis results.

[0088] In one embodiment, the alcohol degradation product may include one or more of methanol and ethanol.

[0089] In one embodiment, the carrier gas may include one or more of oxygen (O2), nitrogen (N2) and argon (Ar).

[0090] In one embodiment, the portable detection device may further include an output unit electrically connected to the sensor unit and outputting the concentration measured from the sensor unit.

[0091] Referring to FIG. 4 above, after the step (S20) of measuring the concentration of the alcohol degradation product, (S30) the step of outputting the concentration of the alcohol degradation product through an output unit electrically connected to the sensor unit may be further included. As shown in FIG. 5(f), the output unit may output the concentration of the alcohol degradation product through a display.

[0092] The present invention relates to a detection device capable of rapidly diagnosing the presence or absence of equipment abnormalities by detecting alcoholic degradation products, such as methanol or ethanol, generated due to the deterioration of insulating paper when partial discharge, overheating, or abnormal phenomena occur inside oil-filled power facilities where eco-friendly ester insulating oil and insulating paper are used as insulating materials. The device of the present invention employs a method in which alcoholic degradation products dissolved in the eco-friendly ester insulating oil are vaporized into a gaseous state by applying heat and ultrasound, the oil in a vapor state is filtered through an oil vapor filter, and then only the alcoholic degradation products are injected into a sensor for detection. When using the detection device presented in the present invention, it offers the advantages of 1) portability, 2) speed, 3) ease of operation, and 4) low cost compared to existing precision analysis devices. The biggest disadvantage of Headspace GC / MS is that it is not portable, making on-site analysis difficult. To address this, the present device is configured so that each component fits within a size that can be carried with one hand, thereby maximizing portability compared to existing precision equipment. Furthermore, the time required to transport eco-friendly ester insulating oil to the laboratory for collection and precision analysis can be reduced. Additionally, this equipment is convenient to operate as it does not require sample pretreatment or post-analysis data processing during precision analysis. Moreover, the purchase cost of precision analysis devices, such as gas chromatography, ranges from tens of millions to hundreds of millions of won. However, the device of the present invention can be priced at several million won. Therefore, it is easy to detect alcoholic degradation products in current eco-friendly ester insulating oil on-site.

[0093] The present invention detects methanol and ethanol generated by the degradation of insulating paper in eco-friendly ester insulating oil during abnormal phenomena such as discharge and overheating in oil-filled power facilities where eco-friendly ester insulating oil and insulating paper are used together as insulators. By heating the insulating oil to elute methanol and ethanol, injecting the resulting gas with the oil vapor removed into a sensor, and outputting the concentration value from the sensor to an output unit, alcoholic degradation products in the eco-friendly ester insulating oil can be simply measured on-site.

[0094] The present invention is a device capable of measuring alcoholic degradation products by heating eco-friendly ester insulating oil in the field using a sensor. While conventional headspace GCs for precise analysis had problems such as requiring laboratory construction and skilled operators, and high construction costs, the device developed in this invention can solve these disadvantages and problems by maximizing field utilization, operational convenience, and portability.

[0095] The present invention relates to a technology in which methanol and ethanol are generated as insulation paper degradation products in oil-filled power facilities, which are primarily facilities using eco-friendly ester insulating oil, and which is in continuous demand due to the increasing trend of demand for eco-friendly power equipment.

[0096] The present invention describes a technology for easily and accurately detecting methanol and ethanol, which are early degradation products of insulation in oil-filled power facilities using eco-friendly ester insulating oil, in the field. In a situation where the importance of preventive diagnosis for the stable operation of oil-filled power facilities using eco-friendly ester insulating oil is increasing, this is a sustainable technology that allows for easy recognition of the advantages of the technology, as it relates to a device for rapid and accurate measurement in the early stages of degradation.

[0097] The present invention is a device for measuring initial degradation products of insulation paper in oil-filled power facilities where insulating oil and insulation paper are used, particularly when eco-friendly ester insulating oil is used. It is applicable to the field of diagnosing the degradation status of power facilities, including oil-filled transformers and cables worldwide, and can open up a new analysis market when applied to the on-site analysis of alcoholic degradation products of insulation paper in oil-filled power facilities using eco-friendly ester insulating oil.

[0098] Furthermore, since there is currently no portable device capable of analyzing methanol and ethanol, which are initial degradation products of insulating paper in eco-friendly ester insulating oil, in the field, the device developed in this invention may have high potential demand both domestically and internationally if utilized in oil-filled power facilities where eco-friendly ester insulating oil and insulating paper are used as insulators.

[0100] Hereinafter, the structure and operation of the present invention will be explained in more detail through preferred embodiments. However, these are presented as preferred examples of the present invention and should not be interpreted in any way as limiting the present invention. Details not described herein can be sufficiently technically inferred by those skilled in the art, so such descriptions will be omitted.

[0102] Examples and Comparative Examples

[0103] Example 1

[0104] (1) Preparation of a portable detection device for alcohol degradation products in insulating oil: A portable detection device as shown in FIGS. 1 to 3 was prepared. Specifically, the portable detection device (1000) comprises: a sample container (100) in which an insulating oil sample (S) is stored; a sample holder (110) on which the sample container (100) is mounted; and a gas pump (200) for injecting a carrier gas (air) into the sample container (100). It includes a sensor unit (300) for measuring the concentration of alcohol degradation products (methanol and ethanol) in an insulating oil sample; the sample holder (110) includes a mounting unit (111) on which a sample container (100) is mounted, a heating means (112) for heating the insulating oil sample, and an ultrasonic application unit (113) provided below the mounting unit (111) for applying ultrasonic waves during heating; the sensor unit (300) is maintained at 200~250℃, and an insulating layer is formed on the outer wall of the sensor unit (300).

[0105] Additionally, a vapor filter (320) is provided at the front end of the sensor unit (300) to filter the vaporized insulating oil from the volatile gas of the transfer pipe. At the rear end of the sensor unit (300), an output unit (400) is provided that is electrically connected to the sensor unit and outputs the concentration of the alcohol degradation product measured by the sensor unit (300). The sample container (100), sample holder (110), gas pump (200), sensor unit (300), and output unit (400) are housed in a housing (10), and a cover (12) is formed on the housing (10) at a position corresponding to the sample container.

[0107] (2) Measurement of alcohol degradation product concentration in insulating oil sample: An ester insulating oil sample from an inflow-type power facility is collected and placed in a sample container (100), and the sample container (100) is mounted on a sample holder (110). Then, a supply pipe (210) in the form of a hollow needle and a transfer pipe (310) are connected to the first hole (101) and the second hole (102) provided on both sides of the upper part of the sample container (100), respectively.

[0108] While heating the insulating oil sample to 80~90℃ using a heating means (112) on the insulating oil sample, ultrasonic waves with a frequency of 30kHz~60kHz were applied through an ultrasonic application unit (113) to generate volatile gas containing alcohol degradation products. A carrier gas was injected into the sample container (100) through a supply pipe (210) from a gas pump (200), and the volatile gas was transferred to a sensor unit (300) through a transfer pipe (310) by the carrier gas. The insulating oil vapor component in the volatile gas was removed through an oil vapor filter (320) and transferred to the sensor unit (300) to measure the concentration of alcohol degradation products. Then, the concentration of alcohol degradation products was output through an output unit (400) electrically connected to the sensor unit (300).

[0110] The present invention has been described above with reference to embodiments. Those skilled in the art will understand that the present invention may be embodied in modified forms without departing from the essential characteristics of the invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the scope of equivalents should be interpreted as being included in the invention. Explanation of the symbols

[0112] 10: Housing 12: Cover 100: Sample container 101: First hole 102: Hall 2 110: Sample holder 111: Mounting part 112: Heating means 113: Ultrasonic application unit 200: Gas pump 210: Supply pipe 300: Sensor part 310: Transfer pipe 320: Vapor filter 400: Output section 1000: Measuring device

Claims

Claim 1 A portable detection device for alcohol degradation products in insulating oil, comprising: a sample container for storing an insulating oil sample; a sample holder on which the sample container is mounted; a gas pump for injecting a carrier gas into the sample container; and a sensor unit for measuring the concentration of alcohol degradation products in the insulating oil sample; wherein the sample holder comprises a mounting part on which the sample container is mounted, a heating means for heating the insulating oil sample, and an ultrasonic application part provided below the mounting part for applying ultrasonic waves when heating, and the sensor unit is maintained at 200~250℃; wherein the insulating oil sample generates volatile gas containing alcohol degradation products when heated by applying ultrasonic waves, and the volatile gas is transported to the sensor unit by the carrier gas to measure the concentration of alcohol degradation products. Claim 2 A portable detection device according to claim 1, wherein one side and the other side of the upper portion of the sample container are respectively connected to a supply pipe and a transfer pipe, and the gas pump injects a carrier gas into the sample container through the supply pipe and transfers the volatile gas to a sensor unit through the transfer pipe. Claim 3 In paragraph 2, the portable detection device further comprises a vapor filter provided at the front end of the sensor section for filtering the vaporized insulating oil in the volatile gas of the transfer pipe. Claim 4 In paragraph 3, the above vapor filter is a portable detection device comprising one or more of cellulose acetate, polyamide, mixed cellulose ester (MCE), polyethersulfone, and polyvinylidene difluoride (PVDF). Claim 5 In claim 1, the portable detection device further comprises an output unit electrically connected to the sensor unit and outputting the concentration measured from the sensor unit. Claim 6 In claim 1, the outer wall of the sensor part is a portable detection device in which an insulating layer is formed. Claim 7 A portable detector according to claim 6, wherein the insulating layer comprises one or more of alumina (Al2O3) and zirconia (ZrO2). Claim 8 A portable detection device according to claim 1, wherein the insulating oil sample is heated to 75~90℃ during heating, and ultrasonic waves of a frequency of 20kHz~60kHz are applied. Claim 9 A portable detection device according to claim 1, wherein the alcohol degradation product comprises one or more of methanol and ethanol. Claim 10 A portable detector according to claim 1, wherein the carrier gas comprises one or more of oxygen, nitrogen, and argon. Claim 11 A method for detecting alcohol degradation products in insulating oil using a portable detection device comprising: a sample container for storing an insulating oil sample; a sample holder on which the sample container is mounted; a gas pump for injecting a carrier gas into the sample container; and a sensor unit for measuring the concentration of alcohol degradation products in the insulating oil sample; wherein the sample holder comprises a mounting part on which the sample container is mounted, a heating means for heating the insulating oil sample, and an ultrasonic application part provided below the mounting part for applying ultrasonic waves during heating; and wherein the sensor unit is maintained at 200~250℃. The detection method comprises: a step of heating the insulating oil sample while applying ultrasonic waves to generate a volatile gas containing alcohol degradation products; and a step of transporting the volatile gas to the sensor unit by the carrier gas to measure the concentration of alcohol degradation products. Claim 12 In claim 11, one side and the other side of the upper portion of the sample container are respectively connected to a supply pipe and a transfer pipe, and the gas pump injects a carrier gas into the sample container through the supply pipe and transfers the volatile gas to a sensor unit through the transfer pipe. Claim 13 In claim 12, the detection method further comprises a portable detection device having a vapor filter provided upstream of the sensor unit to filter the vaporized insulating oil in the volatile gas of the transfer pipe. Claim 14 A detection method according to claim 11, further comprising the step of outputting the concentration of the alcohol degradation product through an output unit electrically connected to the sensor unit after the step of measuring the concentration of the alcohol degradation product. Claim 15 In Clause 11, the detection method wherein the outer wall of the sensor part has an insulating layer formed thereon. Claim 16 A detection method according to claim 11, wherein the insulating oil sample is heated to 75 to 90°C during heating, and ultrasonic waves of a frequency of 20 kHz to 60 kHz are applied. Claim 17 In claim 11, the detection method wherein the alcohol degradation product comprises one or more of methanol and ethanol. Claim 18 In claim 11, the detection method wherein the carrier gas comprises one or more of oxygen, nitrogen, and argon.

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