Full-working-condition auxiliary denitration system and running method

Abstract

The invention discloses a full-working-condition auxiliary denitration system and a running method. The system comprises a water cooling wall, a platen superheater, a tail stage superheater, a tail stage reheater, a heat storage medium heater, a low-temperature reheater, an economizer, an SCR denitration device an air preheater and further comprises a heat storage medium tank and a heat storage medium and feed water heat exchanger; through a heat storage medium pump communicating with a cold heat storage medium outlet of the heat storage medium tank, the cold heat storage medium flow enteringthe heat storage medium heater is subjected to adjusting, the heat storage medium heat absorbing amount and boiler loads are matched, meanwhile, through a feed water adjusting valve and a heat heat-storage medium outlet adjusting valve communicating with the heat heat-storage heat medium outlet of the heat storage medium tank, the heat heat-storage medium flow and the feed water flow entering theheat storage medium and feed water heat exchanger are adjusted, through a bypass feed water adjusting valve, the main feed water flow is subjected to auxiliary adjusting, the smoke temperature entering the SCR denitration device is kept within the optimal running temperature range of the denitration system under the different boiler loads, and the denitration efficiency is ensured.

Description

technical field [0001] The invention relates to the technical field of denitrification for coal-fired power generation, in particular to an auxiliary denitrification system under all working conditions and an operation method. Background technique [0002] One of the main air pollutants produced by coal-fired power plants is nitrogen oxides (NO x ), mainly including nitric oxide (NO) and nitrogen dioxide (NO 2 ), among which nitric oxide (NO) accounts for about x 95% of. Nitrogen oxides (NO x ) are toxic to varying degrees and cause great damage to the environment. In addition, the installed capacity of coal-fired thermal power generation in my country's power system accounts for a large proportion. Combustion produces excessive NO x To pollute the environment, coal should be denitrified. Selective catalytic reduction technology (SCR) denitrification is currently the most mature flue gas denitrification technology. x N 2 and H 2 0. However, the temperature of the re...

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Problems solved by technology

However, the temperature of the reaction catalyst for SCR denitration is required to be at the working temperature (280-420°C). If the temperature is too low, the activity of the catalyst will decrease, resulting in a decrease in the denitrification efficiency. If the temperature is too high, it will easily lead to NO x The amount of production increases, and the activity of the catalyst degrades due to phase change

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