System and method for achieving ultra-low emission of dust and NOx at high temperature

Abstract

The invention provides a system and method for achieving ultra-low emission of dust and NOx at high temperature. Ultra-low emission of the dust and NOx in a high-concentration dust environment can be achieved, SO2, SO3, HCl and HF can be efficiently removed, the floor space is small, the operating energy consumption is low, no wastewater is drained, and the environmental indexes are advanced. The system comprises a coal economizer, a fluidized bed reactor, a cyclone dust collector, an ammonia injection grid, a denitration dust collection tower, a air preheater, an induced draft fan and a chimney which are communicated through flues, a desulfurizing agent supplying system and an ammonia supplying system; a gas inlet of the fluidized bed reactor is connected with the upstream flue, a solid inlet of the fluidized bed reactor is connected with the output end of the desulfurizing agent supplying system, and a flue gas outlet of the fluidized bed reactor is connected with a gas inlet of the cyclone dust collector; an ash discharging port of the cyclone dust collector is connected to the solid inlet of the fluidized bed reactor through a middle ash bin ash discharging device; the ammonia injection grid is arranged in one flue, and the input end of the ammonia injection grid is connected with the ammonia supplying system. Accordingly, ultra-low emission of NOx and the dust in the high-concentration dust environment can be achieved through secondary dust collection.

Description

technical field [0001] The invention belongs to the field of multi-pollutant integrated dry method removal, and relates to the field of integrated removal of dust, NOx and SOx in coal-fired power plant boilers and industrial boilers, specifically a system for ultra-low emission of dust and NOx at high temperature and method. Background technique [0002] my country is rich in coal resources, which can stably meet the demand for electricity for domestic economic development, which determines the pattern of my country's power generation energy dominated by coal. This energy structure and the traditional coal utilization method produce a large amount of air pollutants, such as SOx, NOx, dust and toxic heavy metal mercury. These pollutants will undergo various chemical reactions in the atmosphere to generate more pollutants and form secondary pollution. Mercury is easier to accumulate in the environment than sulfur oxides and nitrogen oxides, and is toxic to humans through the...

AI Technical Summary

Problems solved by technology

These two flue gas purification technologies have obvious shortcomings: first, there is no mature and efficient low-temperature catalyst available, and the flue gas can only be heated to a certain catalytic reaction temperature (300-400°C) for SCR denitrification; The second dust will be deposited on the SCR catalyst, blocking the pores and active sites of the SCR catalyst, resulting in a decrease in denitrification efficiency

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