System and method for realizing machine starting denitration operation

Abstract

The invention relates to a system and method for realizing machine starting denitration operation and belongs to the technical field of coal-fired power station boiler environmental protection. The system comprises a boiler, the boiler is internally provided with a boiler smoke passage, and the boiler smoke passage is internally provided with a final-stage reheater, a low-temperature reheater, aneconomizer and an SCR (Selective Catalytic Reduction) reactor according to the flowing direction of smoke in sequence. According to the system and method for realizing machine starting denitration operation, at the stage of machine starting, a low-temperature reheater steam bypass is adopted to reduce smoke heat absorbed by the low-temperature reheater, adjacent-boiler high-temperature steam is adopted, bypass reheating steam of the boiler is heated, the inlet steam temperature of the final-stage reheater is raised to reduce the heat absorption quantity of the final-stage reheater, and then the inlet smoke temperature of the SCR reactor is raised, and the effective operation of denitration facilities is realized; at the stage of normal operation, according to the actual production requirements, the low-temperature reheating steam bypass and a high-temperature steam pipeline from an adjacent boiler are closed, energy sources are saved, and influence will not be generated to the efficiency of the boiler; and the system is simple and convenient to carry out, furthermore, the investment and operation cost is low, and the system and method for realizing machine starting denitration operation have wide application range.

Description

technical field [0001] The invention relates to a system and method for realizing start-up denitrification and putting into operation, and belongs to the technical field of environmental protection of coal-fired power station boilers. Background technique [0002] Selective Catalytic Reduction (Selective Catalytic Reduction, SCR) refers to the use of reducing agents (such as NH3, liquid ammonia, urea) to "selectively" react with NOx in the flue gas under the action of a catalyst and generate non-toxic Non-polluting N 2 and H 2 O. SCR technology is the most widely used and most efficient flue gas denitrification technology for coal-fired power plant boilers. Affected by the activity of the denitrification catalyst, it is required that the flue gas temperature range of SCR flue gas denitrification is generally 300-420°C. If the temperature is lower than this temperature, the catalyst will be deactivated, so this restricts the start-up of coal-fired power plants and the deni...

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Problems solved by technology

[0003] At this stage, there is a technology to increase the flue gas temperature at the inlet of denitrification by arranging the SCR reactor between the two-stage economizers. Generally, it is the minimum steady combustion load of the boiler to 100% BMCR working condition, and it is impossible to realize the operation of the denitrification facilities in the start-up stage

There is also a technology to introduce high-temperature flue gas at the inlet of the low-temperature superheater into the flue of the denitrification inlet through the bypass flue to increase the flue gas temperature at the SCR inlet. Baffles are generally not tightly sealed, resulting in large air leakage and reduced boiler efficiency

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