Gas measurement and control system and application thereof in denitration flue gas detection

Abstract

The invention discloses a gas measurement and control system. The gas measurement and control system comprises sampling probes, a sampling distribution unit, an analysis unit and a control center, wherein the sampling probes are respectively arranged in all subareas of the cross section of the outlet of the gas channel, and sample gas in all the subareas is continuously equivalently conveyed to the sampling distribution unit interface through the sampling probes in sequence; the sampling distribution unit is used for distributing the sample gas of each subarea into two paths, one path is connected into a subarea inspection sampling group, and the other path is connected into a mixing device; the mixed sample gas is fully mixed by the mixing device and then continuously enters a mixed measurement analyzer, the sample gas in each subarea enters the mixed measurement analyzer in sequence according to a mixed measurement rule through a mixed measurement sampling group, and the synchronismof subarea mixed measurement and mixed measurement is ensured by adjusting specific parameters such as the pipeline length, the mixed sample gas flow and the mixed measurement sample gas flow; and thecontrol center comprises a controller and a big data-artificial intelligence control module, wherein the sampling probes, the sampling distribution unit, the analysis unit and the like are controlledto access the controller, the big data-artificial intelligence control module uses the mixed measurement value as a synchronous reference value to evaluate the patrol measurement value of each subarea, subarea optimization control is completed, and total optimization control is completed by using the mixed measurement value as a control target.

Description

technical field [0001] The invention relates to the technical field of denitrification and environmental protection, in particular to a gas measurement and control system and its application in the detection of denitrification flue gas. Background technique [0002] Thermal power plants have implemented denitrification and environmental protection for more than 10 years. With the further improvement of denitrification efficiency, the NO X Influenced by uneven distribution of concentration field, NO at the outlet of denitrification SCR X The single-point sampling method cannot extract a representative sample gas and cannot reflect the NO of the entire section. X Concentration values ​​are poorly representative, and at the same time, it is impossible to monitor the uneven distribution of pollutant concentration, which causes the problem of excessive ammonia injection in denitrification, resulting in shortened life of denitrification catalysts in some power plants, increased r...

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Problems solved by technology

[0002] Thermal power plants have implemented denitrification and environmental protection for more than 10 years. With the further improvement of denitrification efficiency, the NO X Influenced by uneven distribution of concentration field, NO at the outlet of denitrification SCR X The single-point sampling method cannot extract a representative sample gas and cannot reflect the NO of the entire section X Concentration values ​​are poorly representative, and at the same time, it is impossible to monitor the uneven distribution of pollutant concentration, which causes the problem of excessive ammonia injection in denitrification, resulting in shortened life of denitrification catalysts in some power plants, increased resistance of air preheaters, and electrostatic precipitators due to excessive ammonia injection. A series of problems such as hypertrophy of the pole line, increased power consumption of the induced draft / supply fan, failure of the desulfurization slurry, difficulty in lifting the load of the unit, etc.

[0003] At present, there is an urgent need for a sampling measurement technology that can continuously monitor the evenly mixed flue gas at the outlet section of the denitrification SCR, and can simultaneously intelligently monitor the SCR outlet area. Combined with the optimization of the total amount of ammonia injection and the optimization of area inspection, the big data-artificial intelligence control technology can improve the spraying efficiency. Ammonia timely response and accuracy to solve denitrification SCR outlet NO that power plants are most concerned about X Problems such as uneven concentration field, poor representativeness of single-point measurement, hysteresis of control adjustment, poor quality of automatic input, etc.

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