Portable insulating oil gas content detection device and sealing defect diagnosis method based on gas content

Abstract

The invention relates to a portable insulating oil gas content detection device and a sealing defect diagnosis method based on gas content; the portable insulating oil gas content detection device comprises a case with an upper cover on the case body; the case body internally comprises a gas source module, a chromatographic analysis system, a carrier gas cylinder, a standard gas cylinder and a chromatographic analysis workstation system; the gas source module provides hydrogen and air for the chromatographic analysis system; the chromatographic analysis system is used for completing oil-gas separation and chromatographic analysis of the insulating oil; the carrier gas cylinder and the standard gas cylinder are respectively used for providing carrier gas and standard gas for the chromatographic analysis system; and the chromatographic workstation system is used for realizing equipment sealing defect diagnosis based on gas content data after data acquisition and analysis. According to the invention, automatic calibration of gas component distribution coefficients in the insulating oil is achieved through the internal automatic degassing module, automatic analysis of the content and gas content of dissolved gas components in the oil is achieved, the test precision and accuracy are greatly improved, the detection device can be applied to live and continuous on-site online monitoring of laboratories and equipment, and multiple purposes are achieved through one machine.

Description

technical field [0001] The invention relates to the field of chromatographic analysis of electric insulating oil in the electric power industry, in particular to a portable insulating oil gas content detection device and a sealing defect diagnosis method based on the gas content. Background technique [0002] As the core equipment of the power grid, the safe operation of the transformer is the prerequisite for ensuring the stability of the power grid. Dissolved Gases Analysis (DGA) in transformer insulating oil is one of the most effective means to discover and diagnose latent faults inside transformers. The analysis of gas content in oil is to detect the sealing failure of electrical equipment early and avoid ultra-high voltage and special faults. An effective technical means for the discharge of air bubbles inside high-voltage electrical equipment and the occurrence of water ingress and damp faults. At present, the analysis of dissolved gas in insulating oil and the analy...

AI Technical Summary

Problems solved by technology

However, due to the influence of factors such as changes in device sensor measurement conditions, component test accuracy, and performance aging, online monitoring analysis has problems such as large fluctuations in monitoring data, deviations in monitoring data after long-term operation, and high false alarm rates. Regular off-line comparisons are required. On-site verification of analytical or application standard oil samples

[0004] The off-line analysis method is based on "GB / T 17623-2017 Gas Chromatographic Determination of Dissolved Gas Component Content in Insulating Oil", using 100mL glass syringe for on-site sampling, and then transported back to the laboratory for mechanical vibration degassing (manual headspace gas), the balance gas is transferred to a 5mL syringe, and then a certain amount of sample balance gas is manually injected into the gas chromatograph through a 1mL syringe for analysis. This method is the most widely used, but this method is performed automatically by the workstation , the rest of the operation involves manual work, and is affected by various factors such as the sealing effect of the sampling syringe, the infiltration of outside air caused by the repeated vibration of the needle core during the sample transportation, cumbersome manual operation steps, and the operating level of the test personnel. Disadvantages such as length and poor repeatability of results

[0005] The determination of gas content in insulating oil is mainly carried out by offline sampling. The determination methods include "DL / T 703-2015 Gas Chromatographic Determination of Gas Content in Insulating Oil" and "DL / T423-2009 Determination of Gas Content in Insulating Oil" There are two kinds of vacuum differential pressure method, and the principle of vacuum differential pressure method and chromatographic measurement method are different. Therefore, two different instruments need to be used to detect the dissolved gas components in oil and the gas content in oil respectively. The cost of instrument purchase and workload Relatively large; and DL / T 703 although the determination principle is the same as GB / T 17623, but because generally only the O in the oil is taken 2 , N 2 , CO and CO 2 The calculation of the gas content is carried out, therefore, the performance requirements for the test instrument are relatively low. In addition, it has the same disadvantages as the offline analysis method of dissolved gas in insulating oil. Except that the data processing is automatically completed by the workstation, the operation links are all involving manual work. In the atmospheric environment O 2 , N 2 , CO 2 The gas concentration is very high. Therefore, the sealing effect of the sampling syringe, the external air infiltration caused by the repeated vibration of the needle core during the sample transportation, the air infiltration in the cumbersome manual operation steps, and the insufficient operation level of the test personnel cause air to enter the sample. These factors greatly affect the repeatability and reproducibility of the measurement results, resulting in the long-term problems of poor repeatability and distortion of the measurement results of the gas content of insulating oil.

In addition, for the data analysis of the gas content in insulating oil, there is only one standard for whether it exceeds the standard in the existing relevant standards, and there is no further judgment basis based on the relationship between the gas content analysis data and the sealing state of the equipment

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