On-line measuring apparatus for absolute humidity of gas in flue gas or pipeline gas

Abstract

The invention provides an on-line measuring apparatus for absolute humidity of gas in flue gas or pipeline gas. The apparatus comprises a gas extraction unit, a gas tracing heat conveying unit, a wet-oxygen testing unit, a gas condensation unit, a gas flow metering, extracting and sampling pump, a dry-oxygen testing unit, a computer control analysis and data sending unit. The on-line measuring apparatus can be used for directly measuring heat and humidity concentration value of SO2, NO, and NO2, only absorption spectrum is analyzed and a result is obtained, hardware is not needed to increase,and cost performance of the integral flue gas continuous on-line monitoring system is improved.

Description

technical field [0001] The invention belongs to the technical field of gas humidity monitoring, and in particular relates to an online measuring device for gas absolute humidity in flue gas or pipeline gas. Background technique [0002] At present, my country's economy is in a period of rapid growth, the country attaches great importance to environmental protection, and relevant policies and regulations have been introduced one after another. Especially with the promulgation and implementation of ultra-low emission monitoring regulations for flue gas, the humidity of flue gas after wet desulfurization and ammonia denitrification is relatively high. In order to correctly measure the low concentration of SO in flue gas 2 and NO x , it is necessary to correctly measure the humidity of the flue gas to complete the conversion of dry base emissions. [0003] The online monitoring methods of flue gas humidity include: condensation method (weight method, volume method), capacitanc...

AI Technical Summary

Problems solved by technology

The capacitance method to measure the flue gas humidity is based on the principle of the difference in the dielectric constant of water and water vapor to measure the humidity of the flue gas. It is suitable for measuring low temperature flue gas and cannot realize the measurement of high temperature flue gas.

[0004] At present, there are electrochemical sensor method, zirconia method, and paramagnetic oxygen method to measure the oxygen content of flue gas. Among them, the electrochemical sensor method uses a chemical sensor with electrolyte added. The temperature of the oxygen gas is higher than 100°C, so the electrochemical sensor method cannot be used to measure wet oxygen; the zirconia method can realize high temperature measurement, but when the process sample gas temperature suddenly becomes cold, or contains a large amount of water vapor, the zirconium tube It is easy to burst, resulting in high purchase and operation costs; the measurement of paramagnetic oxygen method is affected by polar gases, and SO in flue gas 2 , NO, NO 2 Both are polar gases, which affect the measurement results

Images