Methyl bromide concentration calculation method and detection system

Abstract

The invention discloses a methyl bromide concentration calculation method and detection system. The method includes: acquiring the heat conductivity of mixed gas; acquiring the concentration of carbondioxide and the humidity of dry air; determining function relationship between the volume fraction of the dry air and the concentration of methyl bromide according to the concentration and the humidity; calculating the concentration of the methyl bromide according to the heat conductivity of the mixed gas, the heat conductivity of each component, the concentration, the humidity and the function relationship. The methyl bromide concentration calculation method and detection system has the advantages that the concentration of the methyl bromide can be accurately calculated by acquiring the gasheat conductivity, and accordingly chemical adding quantity can be precisely controlled, and fumigation cost can be saved; meanwhile, due to the fact that the methyl bromide is toxic and harmful gas,the method and system can reduce chemical waste and further reduce pollution to protect environments; due to real-time data transmission, the fumigation process can be monitored conveniently.

Description

technical field [0001] The invention relates to the field of concentration detection of fumigant gas such as methyl bromide, in particular to a method for calculating the concentration of methyl bromide and a detection system. Background technique [0002] With the increase in the number of imported timber, fruits and vegetables, grain and forage grass in my country, the problems of biosecurity and biological invasion have become increasingly prominent; the construction of fumigation treatment facilities at inspection and quarantine ports that meet national standards has become the key to the above problems. An effective solution. Methyl bromide has excellent properties and is currently one of the commonly used fumigants. In order to precisely control the dosage and save production costs, it is necessary to monitor the environment of the fumigation warehouse at the same time to make the fumigation process meet the national standards. [0003] The fumigation is performed by ...

AI Technical Summary

Problems solved by technology

Usually, an infrared spectrometer can only measure one kind of fumigant gas, and if there are overlapping absorption peaks between interfering gases and fumigant gases such as methyl bromide, it will bring large errors to the measurement

At the same time, infrared absorption requires a long optical path, and the absorption effect will be more significant. Therefore, it is necessary to design and manufacture a special absorption cavity, which restricts the miniaturization of the equipment; too precise absorption cavity also faces the problem of being polluted by dust and water vapor. reduce the measurement accuracy of the method

The high-voltage equipment used in emission spectrometry is inherently dangerous. Some fumigants such as methyl bromide are flammable and explosive gases at room temperature. The environment of the fumigation warehouse is harsh and the air humidity is high. This scheme has certain potential safety hazards.

At the same time, this measurement method needs to reduce the sample gas pressure, resulting in increased system complexity, high failure rate, and high maintenance costs

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