Online grid type itinerant detection system for gas components at SCR outlet

Abstract

The invention discloses an online grid type itinerant detection system for gas components at an SCR outlet. According to the scheme, the system comprises a sampling device, a blowback device, a switching control device, an analysis device and an upper computer, the through-flow cross section of a flue gas channel is averagely divided into M*N detection areas with the same area, and the sampling device comprises M*N probes arranged in the centers of the detection areas; the blowback device comprises an air compression pump, a compressed air tank and a blowback spray head; and an air outlet pipeof the blowback spray head is arranged towards a dustproof filter screen connected to a sampling pipe of the probe. The probes are uniformly distributed in the through-flow cross section of the fluegas channel, the sampled gas is sequentially conveyed into the analysis device through the switching control device according to a preset sequence, the NO concentration and the O2 concentration in thesampled gas are detected so as to improve the measurement accuracy, and the dustproof filter screen is periodically cleaned by arranging the blowback device, so that the reliability and the stabilityof gas detection are further improved.

Description

technical field [0001] The invention relates to the technical field of denitrification of power plants, in particular to an on-line grid-type circuit detection system for gas components at an SCR outlet. Background technique [0002] At present, most thermal power plants use Selective Catalytic Reduction (SCR) for denitrification. The optimal operation of the SCR system is an important part of ensuring that the power plants meet the increasingly stringent environmental protection requirements. The core of the optimal operation adjustment of the SCR system is to accurately measure the distribution of the NOx concentration field and then to match the optimal adjustment of the amount of ammonia injection. [0003] At present, most of the equipment used in power plants can only obtain the NOx concentration of 1-2 measuring points. However, the flow field of the flue gas in the actual flue is very uneven, the catalyst activity is also different, and the NOx concentration distribu...

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Problems solved by technology

[0003] At present, the equipment used in most power plants can only obtain the NOx concentration of 1-2 measuring points, but the flow field of the flue gas in the actual flue gas is very uneven, the catalyst activity is also different, and the NOx concentration distribution also has a large gradient, which means Therefore, the representativeness of the existing NOx concentration measurement data is very poor, and it cannot meet the requirements of the fine adjustment of the SCR system, and it is impossible to realize the optimal adjustment of the ammonia injection grid.

[0004] In addition, ammonia escape caused by excessive ammonia injection under ultra-low emissions has become a major threat to the normal operation of air preheaters and induced draft fans in power plants

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