SCR DeNOx Project Transformation In Dingzhou Power Plant

Coal-fired power plant is one of the main emission sources of NOX. With economic development and energy consumption growth, NOX emission has been increasing. NOX has great harm on environment and human health, thus it is necessary to carry out the transformation of coal-fired power plants to reduce NOX emissions, which is inevitable. During the “Twelfth Five” period, reduction of NOX emission is the focus of China’s regulation of air pollution.This paper studies the denitration renovation project of Phase I Project(2×600MW) and Phase II Project(660WM) in Dingzhou Power Plant. First, this paper relate the present situation of denitration technology and denitration transformation of coal-fired power plant. Through comparison of SCR, SNCR and SCR-SNCR combined methods, and consideration of the operation status, Phase I Project should undergo the low NOx combustion transformation, then the SCR De NOx transformation. While the Phase II Project are directly carried out SCR DeNOx transformation. SCR reactor was arranged between the boiler economizer and air preheater, which was high dust arrangement way. The gas velocity in the reactor was selected as 4~6m/s. The catalyst was picked as honeycomb. After denitration transformation, many parameters met the design requirements: denitration efficiency is not less than 80%, ammonia escape rate <3ppm, SO2/SO3 conversion rate <1%, pressure drop of denitrification system ≤ 1100 Pa. Renovation of related equipment and steel were introduced when installing denitrification equipment. And start and stop of SCR system were stated.Before installing denitration system, # 1, # 2, # 4 unit boiler SCR inlet NOX concentrations are 300 mg / Nm3 meter, three furnaces annual emissions of 9926 t / a(annual utilization hours of 5500 hours meter, the same below). After denitration project put into operation, three units after denitration of flue gas NOX emissions is 60 mg / Nm3, three furnaces annual emissions of NOX is 1985 t / a, annual emissions of 7941 t / a, reduction rate of 80%. After the study found, run denitration system has little effect on the operation of the boiler unit, but for devices such as air preheater some maintenance have more stringent requirements. In addition, estimates of project investments for static investment 268.86 million yuan, 149 yuan of investment units / kW, Denitration works on the business of the average tariff of 6.44 yuan / MWh.The results showed that the denitration renovation and operation has great significance in NOX emission reduction, and bring good environmental benefits for the local area.