Ultraviolet differential flue gas concentration measuring systems calibration method and enforcement device

Abstract

The invention relates to online monitoring of flue gas, in particular to a calibration method and an implementation device for an ultraviolet differential flue gas concentration measurement system. The invention aims to provide the high-precision calibration method and the high-precision calibration device and simply and quickly complete calibration for the flue gas concentration measurement system. The invention adopts the technical proposal that: all sample cell packs are communicated and well sealed; standard concentration gas with fixed pressure is led in; after the gas is fully uniformly, sample cells are placed into a light path, thereby ultraviolet light can penetrate gas to be measured in the sample cells; the concentration of the gas to be measured with different equivalent concentrations can be obtained by placing the sample cells with different lengths; spectral curves are acquired and recorded under each concentration; the gas concentration is calculated according to the ultraviolet difference method; and least square fit of theoretical values and actual measured values of the equivalent gas concentrations obtained by utilization of standard concentrations and the lengths of the sample cells is performed through calibration software, and then calibrated concentration measuring coefficients are obtained. The calibration method and the implementation device are mainly applied to online monitoring of the flue gas.

Description

technical field [0001] The invention relates to online monitoring of flue gas, in particular to a calibration method and implementation device for an ultraviolet differential flue gas concentration measurement system. Background technique [0002] Sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ) as the main gas pollution of the atmospheric environment, emission reduction and monitoring are getting more and more attention. In order to timely, accurately and systematically grasp the status of pollutant discharge, continuous monitoring of discharge conditions such as sulfur dioxide is required. At present, the commonly used continuous gas monitoring methods are sampling method, absorption spectrometry and so on. The Lambert-Beer light absorption law is the most basic law for measuring the concentration of substances by absorption spectroscopy, that is, in the ultraviolet-visible band, when the incident light intensity is constant, the absorbance of the measured substance i...

AI Technical Summary

Problems solved by technology

The current commonly used calibration method is to fill the sample cell with different concentrations of the measured gas when the length of the sample cell is constant. At this time, the pressure of the measured gas has an impact on the concentration, especially when the required When the concentration of the gas to be measured is low, controlling the gas concentration by this method will produce a large measurement error, which cannot meet the requirements of measurement accuracy, and several standard gases with different concentrations are used for calibration, which is costly and difficult to fit. Less, low precision

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