Denitrification system employing multidirectional-spraying SNCR and single-layer SCR

Abstract

The invention relates to a denitrification system employing multidirectional-spraying SNCR and single-layer SCR. The system includes: a plurality of spray guns which are respectively arranged on a front wall, a back wall, a side wall and a top of a furnace; an SCR reactor which is arranged between a economizer and an air pre-heater which are arranged in a boiler unit; an ammonia water storage tank which is connected to the spray guns through ammonia water pipelines; an ammonia water flow controlling apparatus and a high pressure apparatus which are arranged on the ammonia water pipelines; a compressed air tank which is connected to the high pressure apparatus; an gas sensor which is arranged in a communicating pipeline between a dust-removing device and a desulfurizing apparatus in the boiler unit; and a central controller which is disposed in a monitoring room. Ammonia water is transported to the spray guns through the high pressure apparatus. The central controller is respectively connected to the ammonia water flow controlling apparatus, the high pressure apparatus, the gas sensor and the SCR reactor and controls the ammonia water flow controlling apparatus, the high pressure apparatus and the SCR reactor. By means of the system, denitrification efficiency can reach 90-95%, a cost is just 60% of a conventional SCR denitrification technology and an operation cost is just as 70% as the conventional SCR denitrification technology. The denitrification efficiency is high and the cost is low. A significant contribution can be made to present severe air pollution.

Description

technical field [0001] The invention relates to the field of boiler flue gas denitrification, in particular to a multi-directional injection SNCR plus single-layer SCR denitrification system. Background technique [0002] In order to meet the increasingly stringent environmental protection requirements, GB13223-2011 "Emission Standard of Air Pollutants for Thermal Power Plants" is implemented, and in today's very severe smog and air pollution environment, it is necessary to denitrify the flue gas containing nitrogen oxides. [0003] The current denitrification process methods include selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR). The denitrification efficiency of SCR can reach 80-90%, and the denitrification efficiency of SNCR is generally ≤60%. Although the efficiency of the SCR denitrification process is high, the investment cost is very expensive and the operating cost is also very high; although the investment cost and operating cost o...

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Problems solved by technology

Although the efficiency of the SCR denitrification process is high, the investment cost is very expensive and the operating cost is also very high; although the investment cost and operating cost of the SNCR denitrification process are relatively low, the denitrification efficiency is limited, and it can only be used in the fluidization of high temperature cyclone separation. The denitrification effect of 60% is only on the bed boiler. If it is on the pulverized coal boiler, low-temperature cyclone separation fluidized bed boiler and chain boiler, because there is no flue gas collecting section with a temperature of 850~1050, the denitrification efficiency is not as high as 40%; therefore, in view of the above status quo, it is necessary to innovate and design a new type of denitrification system

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