Method and device for dynamic gas mixing and filling under pressure within wide range

Abstract

The invention provides a method and device for dynamic gas mixing and filling under pressure within a wide range. The method comprises the steps that SF6 gas and sample gas are mixed under the control of a mass flow controller, and the concentration of the sample gas is reduced; the diluted sample gas and the SF6 gas are mixed and diluted under the control of a mass flow controller; the sample gas subjected to secondary dilution and the SF6 gas are mixed and diluted under the control of a mass flow controller; and finally, the mixed gas is injected into a standard gas cylinder. According to the device, an SF6 gas cylinder is connected with the standard gas cylinder through a main gas circuit, and the main gas circuit is sequentially provided with a pressure reducing valve, a first mass flow controller, an electromagnetic valve, a first static mixer, a second mass flow controller, a second static mixer, a third mass flow controller, a third static mixer, a buffer tank, an electromagnetic proportioning valve and a diaphragm press; the SF6 gas cylinder is also connected with the input end of the second static mixer through a fourth mass flow controller and connected with the input end of the third static mixer through a fifth mass flow controller; and sample gas cylinders are all connected with the input end of the first static mixer through a sixth mass flow controller.

Description

technical field [0001] The invention provides a pressure wide-area dynamic gas distribution filling method and device suitable for the calibration of sulfur hexafluoride analyzers, which belongs to the field of dynamic gas distribution technology, and specifically refers to the use of dilution and pressurization technology to realize wide-area dynamic standardization. Air preparation. Background technique [0002] Sulfur hexafluoride gas has good insulation and arc extinguishing properties, and has been widely used in gas-insulated electrical equipment. In recent years, with the operation of UHV AC / DC substations, a large number of high-voltage sulfur hexafluoride electrical equipment has been included in the daily technical supervision work, and now most of them use SF 6 Gas decomposition product meter, SF 6 Implementation of SF by gas purity meter, etc. 6 Quality supervision of electrical equipment. In order to ensure the measurement accuracy of the instrument, the abo...

AI Technical Summary

Problems solved by technology

In order to ensure the measurement accuracy of the instrument, the above-mentioned instruments need to be calibrated regularly. At present, the gas distribution instrument is mostly used in the laboratory to prepare the standard gas to SF 6 Analyzer calibration, there are two problems in the existing gas distribution technology: one is that the most advanced gas distribution instrument currently controlled by a mass flow meter has a maximum single-channel ratio (volume ratio) of up to 1:70, that is, the minimum gas concentration (volume ratio) ratio) is 14286ppm, and the minimum concentration of the calibration gas required for calibration of the sulfur hexafluoride decomposition product instrument in the laboratory is 2ppm. Therefore, in the actual calibration process, the calibration gas with a concentration of about 50ppm is first prepared in the steel cylinder by the syringe quantitative method 1 , after being quantified by the chromatograph; then, using the standard gas 1 as the gas source, a 2ppm standard gas 1 is prepared with the help of a gas distribution device. This method has problems such as cumbersome operation, low efficiency, high accuracy, and easy introduction of other impurities.

Second, the existing gas distribution instrument is relatively large, and SF can only be carried out in the laboratory. 6 Analyzer calibration work, SF in substation 6 The calibration work of the analyzer is mainly through the known concentration of the standard gas cylinder to the SF 6 Analyzer calibration, and the output gas pressure of the gas distribution technology is normal pressure gas, which cannot be filled with gas, so a pressure wide-range dynamic gas distribution device is urgently needed

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