Efficient SCR (Selective Catalytic Reduction) denitrification structure and method for realizing full load operation

Abstract

The invention provides an efficient SCR (Selective Catalytic Reduction) denitrification structure and method for realizing full load operation, and aims to increase denitrification efficiency, reduce generation of SO3 and solve the problem of ABS (Acrylonitrile Butadiene Styrene) sedimentation while realizing full load operation of an SCR denitrification system. The efficient SCR denitrification structure is characterized in that a hearth communicates with a first-level coal economizer; the first-level coal economizer communicates with an SCR reactor; a second-level coal economizer is arranged between a first-layer catalyst and a second-layer catalyst; the second-level coal economizer communicates with the first-layer catalyst and the second-layer catalyst; the second coal economizer communicates with a heat exchange medium circulation pipeline; the heat exchange medium circulation pipeline communicates with the first-level coal economizer; a feed pump communicates with the second-level coal economizer. Flue gas of the hearth is subjected to heat exchange in the first-level coal economizer and is introduced into the SCR reactor; firstly, the flue gas undergoes a denitrification reaction through the first-layer catalyst, and is then subjected to heat exchange in the second-level coal economizer to be cooled further; the cooled flue gas passes through the second-layer catalyst and a third-layer catalyst to undergo a denitrification reaction, and is discharged.

Description

technical field [0001] The invention relates to a high-efficiency SCR denitrification structure and method capable of realizing full-load operation, and belongs to the field of SCR flue gas denitrification in coal-fired power stations. Background technique [0002] With the national air pollutant NO from coal-fired power stations X With the improvement of control standards, most of the active units have undergone denitrification transformation. Among the many denitrification methods, Selective Catalytic Reduction (SCR) flue gas denitrification technology has become the first choice for denitrification transformation of large thermal power units due to its high denitrification efficiency and mature technology. technology. SCR denitrification mechanism is: nitrogen oxides (NO X ) and reducing agent (NH 3 ) are mixed and transformed into harmless nitrogen and water under the action of a catalyst. [0003] The catalyst in the SCR denitrification system of the coal-fired unit...

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Problems solved by technology

Although this process can ensure that the flue gas temperature at the inlet of the SCR denitrification device meets the minimum continuous operation requirements under the low-load and high-load conditions of the boiler, since the subsequent heat exchange device is arranged at the outlet of the SCR denitrification device, although the flue gas temperature at the inlet of the SCR denitrification device is increased to meet minimum continuous operating temperature requirement, but while causing SO 2 / SO 3 The further increase in conversion rate exacerbates the problem of ABS deposition in subsequent equipment

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