| Coal-fired boilers are widely used in industrial processed, mercury pollution of which has caused high attention of governments. Many countries have raised the mercury emission of coal-fired boilers control standards, and many scholars have studied the mercury emission of coal-fired boilers and mercury content in coal. transformation law theory of mercury in the flue gas of coal-fired boilers has matured at present. In the condition clearly understanding on transformation law, domestic and foreign scholars have studied on not only mercury control efficiency of existed pollution control device, but also a lot of practical techniques of mercury control. The related content has been analyzed in the paper.Mercury control efficiency of the common coal-fired boilers pollutants devices has been analyzed in the paper, which based on the research results of mercury control technologieswritten by domestic and foreign scholars and to guide coal-fired boiler mercury control of design calculation. The analysis of mercury mass balance data of 16 power plants showed out 3 conclusions. The first is that denitration unit can not remove mercury in the flue gas of coal-fired boilers, but it can improve mercury control efficiency of dedusting unit and desulfurization unit. The second is that bag filter mercury control efficiency is higher than electrostatic precipitator mercury control efficiency. The third is that compared with pulverized coal boiler existed pollution control device mercury control efficiency, circulating fluidized bed boiler existed pollution control device mercury control efficiency is higher. According to the research results, selected values recommended list of common pollution control devices mercury control efficiency in the coal-fired boiler design calculation process is finishedIn order to further guide coal-fired boiler mercury control design calculations, the formulas about mercury control efficiency calculation mercury removal efficiency of 6 power plants were analyzed at the paper, which is based on Chinese mercury emission limits standard. Studies have showed out that the existed contaminants devices can basically guarantee mercury from coal-fired boiler under the national mercury standard limit. For the coal-fired boiler of the Yunnan-Guizhou Plateau whose coal had higher levels of mercury, only if the mercury removal efficiency of engineering pollutants devices could be 90%～95%, would mercury from the most coal-fired boiler be controlled under the national mercury standard limit. Combined with the ideal gas theory by the analysis of the actual degree of influence of mercury on the coal-fired boiler flue gas volume showed out that mercury on flue gas volume has little effect, even can be neglected. |
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