Determination and pre-concentration device for volatile organic compounds in ambient air and application of determination and pre-concentration device

Abstract

The invention belongs to the technical field of environmental protection detection, and particularly relates to a determination and pre-concentration device for volatile organic compounds in ambient air. The device comprises: an enrichment and analysis module including refrigeration, cold trap enrichment and thermal analysis; a gas circuit module comprising a first gas circuit, a second gas circuit, a third gas circuit and a fourth gas circuit, wherein the first gas path is a sample gas path, the second gas path is a carrier gas and / or purging gas path, and the third gas path and the fourth gas path are analyzer carrier gas paths; and a valve module comprising a six-way valve, a ten-way valve and a second electromagnetic valve, wherein the six-way valve is connected with the enrichment and analysis module and is used for enriching and analyzing sample gas, the ten-way valve is connected with a quantitative loop and is used for quantitatively analyzing the sample, and the second electromagnetic valve is connected with the six-way valve and the ten-way valve so as to intercept the sample gas. According to the invention, the semiconductor refrigeration effect is effectively improved, and the service life of the refrigeration sheet is prolonged.

Description

technical field [0001] The invention belongs to the technical field of environmental detection, and in particular relates to a device for measuring and pre-concentrating volatile organic compounds in ambient air and its application. Background technique [0002] Volatile organic compounds (VOCs) refer to organic compounds that participate in atmospheric photochemical reactions. They are important precursors for the formation of ozone and PM2.5, which will cause environmental pollution. At the same time, long-term exposure will cause serious harm to human health. Accurate detection of the concentration of volatile organic compounds provides an effective basis for the governance and control of VOCs. Due to the wide variety of volatile organic compounds in the ambient air, large boiling point span, and low concentration, the corresponding detection equipment is required to have a lower detection limit and higher accuracy. [0003] Most of the existing detection equipment adopt...

AI Technical Summary

Problems solved by technology

The refrigeration technologies in the pre-concentration pretreatment device mainly include semiconductor electronic refrigeration, liquid nitrogen refrigeration, and compressor mechanical refrigeration solutions, but there are different defects that limit their use.

Liquid nitrogen refrigeration is expensive; the volume of compressor refrigeration is too large and Freon needs to be added regularly, polluting the environment

[0004] The semiconductor refrigeration effect is poor and not resistant to high temperature, so it is necessary to make improvements to overcome the deficiencies in practical applications

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