System and method for detecting concentration of specific component in mixed gas

Abstract

The invention discloses a system and a method for detecting the concentration of a specific component in mixed gas. A multi-channel photoelectric detector of the concentration detection system is provided with at least two detection channels, one of the detection channels is a reference channel, and the other detection channel is a to-be-detected gas channel. Infrared light emitted by an infrared light source passes through an optical gas chamber and then reaches the to-be-detected gas channel, corresponding to a to-be-detected component, of the multi-channel photoelectric detector, and a signal output by the to-be-detected gas channel is sequentially processed by a filter amplification circuit and an analog-to-digital conversion circuit and then enters a processor, and thus the ratio of the peak-to-peak value of the output signal of the to-be-detected gas channel to the peak-to-peak value of the output signal of the reference channel is obtained. The ratio is input into a computer, and the computer calculates the concentration of the specific component in the mixed gas according to the ratio and a built-in concentration inversion model. According to the invention, the concentration of various components in the gas to be detected can be simultaneously detected, the detection precision is high, and the error is less than 4.5%. Meanwhile, the size is small and the weight is light.

Description

technical field [0001] The invention relates to automobile tail gas monitoring, coal mine gas monitoring and atmospheric environment detection, in particular to a system and method for detecting the concentration of specific components in a mixed gas. The invention can simultaneously detect CO and CO in the tail gas 2 、C 3 h 8 The concentration belongs to the technical field of gas detection. Background technique [0002] With the rapid development of industry, the discharge of various harmful gases has been increasing, causing serious air pollution, and air pollution has received more and more attention. In air pollution, motor vehicle exhaust is an important source of pollution. Studies have shown that the pollution caused by motor vehicle exhaust accounts for about 60% of the air pollution in the whole city. Motor vehicle exhaust has complex components, including carbon monoxide (CO), carbon dioxide (CO 2 ), hydrocarbon mixtures and suspended particles, etc. The mos...

AI Technical Summary

Problems solved by technology

In order to control exhaust pollution, many pollution control technologies have emerged. Along with the treatment technologies, there have been many measurement methods for automobile exhaust (including composition measurement and concentration measurement). For example, Anhui Optoelectronics Research Institute uses TDLAS to measure the concentration of automobile exhaust, and its existing measurement equipment is expensive. , bulky, heavy, inconvenient to move and other deficiencies, making it difficult to be widely promoted

North University of China uses NDIR to monitor the concentration of gas in coal mines, but the CO and CO in the coal mines it monitors 2 The monitoring concentration ranges are 0-4.45% and 0-4.8%, respectively, while the CO concentration range in automobile exhaust is 0-14%, CO 2 The concentration range is 0-20%, so it cannot meet the requirements of CO and CO in automobile exhaust 2 measurement requirements

At the same time, the existing technology usually can only measure the concentration of one component in the gas to be measured at a time. If multiple components are to be measured, it needs to be measured several times separately, resulting in low measurement efficiency and complicated structure.

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