Differential high-concentration particle measurement system and method based on dynamic Faraday cup

Abstract

The invention relates to a differential high-concentration particulate matter measurement system and method based on a dynamic Faraday cup. The measurement system includes a dynamic Faraday cup one and a dynamic Faraday cup two. The dynamic Faraday cup 1 includes a unipolar charger 1, an electromigration classifier 1, and a shielding box 1 which is covered on the outside of the unipolar charger 1 and the electromigration classifier 1. The second dynamic Faraday cup includes the second unipolar charger, the second electromigration classifier, and the second shielding box which is covered on the outside of the second unipolar charger and the second electromigration classifier. The measurement system and method can solve the deficiencies in the prior art, meet the continuous measurement of high-concentration particles, accurately invert the measurement of particle number concentration and median particle size, and can effectively eliminate system errors and ensure measurement accuracy.

Description

technical field [0001] The invention relates to the technical field of measuring the number concentration and median diameter of high-concentration particulate matter, in particular to a differential high-concentration particulate matter measurement system and method based on a dynamic Faraday cup. Background technique [0002] For the emission of high-temperature and high-concentration particles from combustion sources such as diesel vehicles, construction machinery and coal-fired power plants, the traditional method first dilutes the high-concentration particles and then measures them. The two back-end measurement technologies are divided into two categories, one is through condensation Counting technology, the particles to be measured enter the condensation growth chamber, and enter the optical measurement chamber after growing up, and the concentration value of the particles is retrieved through the light scattering intensity of the particles; the other is through the dif...

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Problems solved by technology

[0002] For the emission of high-temperature and high-concentration particles from combustion sources such as diesel vehicles, construction machinery and coal-fired power plants, the traditional method first dilutes the high-concentration particles and then measures them. The two back-end measurement technologies are divided into two categories, one is through condensation Counting technology, the particles to be measured enter the condensation growth chamber, and enter the optical measurement chamber after growing up, and the concentration value of the particles is retrieved through the light scattering intensity of the particles; the other is through the diffusion charging technology, the particles to be measured enter the charging chamber chamber, so that the particles are charged, and then the charged particles are collected through the filter to measure the current value of the particles; the main defect of the condensation counting technology is that the concentration of particles cannot be higher than 1E6# / cm3, and the particles with high concentrations must be diluted before measurement, and this technique cannot obtain the median particle size of particles

Although the diffusion charging technology has improved the particle concentration measurement range, it is easy to block the collection filter for measuring the particle charge at the back end for the measurement of high concentration particles, which is not suitable for continuous measurement and the maintenance cycle is short

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