A kind of sncr denitrification system control device and denitrification control method

Abstract

The invention discloses a SNCR denitration system control device which comprises a reductant feeding device, a denitration device and a PID control device. Multiple smoke pipes are arranged at an outlet of a coal economizer and connected with a smoke mixing box which is connected with a sampling port of a smoke analyzer through a sampling pipe, the PID control device comprises a comparator, a PIDcontroller and a microcontroller, and the PID controller comprises a proportioner, an integrator, a differentiator and an summator. The invention further discloses a SNCR denitration control method. The SNCR denitration system control device is simple in structure and reasonable in design, and the smoke pipes are arranged at the outlet of the coal economizer, control delay time is reduced, controlaccuracy is improved, consumption of a denitration reductant is lowered, different control intervals are divided, and P control, PI control or PID control is adopted for different control intervals;the SNCR denitration system control device is high in practicability, good in using effect and convenient for popularization and use.

Description

technical field [0001] The invention belongs to the technical field of denitrification devices, and in particular relates to an SNCR denitrification system control device and a denitrification control method. Background technique [0002] Nitrogen oxide is a gas produced by the oxidation of nitrogen during the combustion process. It not only stimulates the human respiratory system, damages animals and plants, and destroys the ozone layer, but is also one of the main substances that cause the greenhouse effect, acid rain, and photochemical reactions. The emission limits of nitrogen oxides are becoming stricter all over the world, and thermal power plants, as the main source of nitrogen oxide gas emissions, have received extra attention in reducing their emissions. [0003] SNCR is a well-developed nitrogen oxide control technology. The main principle of SNCR is to inject nitrogen agent into the high-temperature flue gas at 870 ° C ~ 1150 ° C without the action of a catalyst,...

AI Technical Summary

Problems solved by technology

[0004] At present, there are many applications of CFB-SNCR technical engineering, but there are still some problems. One of the problems is that nitrogen oxides are generated by the reaction in the separator, and then reach the nitrogen oxide measurement place through economizer, air preheater and other equipment (into At the horizontal flue at the chimney entrance), the nitrogen oxide value measured by the nitrogen oxide analyzer lags by 7-8 minutes; and only one probe is installed at the measurement point, which is easy to cause inaccurate measurement values ​​due to uneven distribution of flue gas

Eventually, the control deviation of nitrogen oxides will be large, the consumption of reducing agent will be high, and the operating cost of the power plant will increase

[0005] In addition, the current denitrification control adopts a single control method, and there is no different control for different stages or different errors, and the control is not flexible.

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