Research And Application Of Colored Plume Control Technology In Coal Fired Power Plant

With the"speed-up"of ultra-low gas emission for coal-fired power plants in China,most of the coal-fired generating units in the middle and east of China have achieved ultra-low emission.However,the emission problems such as colored plume,SO₃ and salt dissolved in flue gas droplets are a concern to the public.Therefore,it is urgent to carry out the research on the technology of colored plume control and collaborative removal of related pollutants.By analyzing the causes and main influencing factors of the colored plume,and comparing the various colored plume control technologies,the paper developed the research on the technology of colored plume control and collaborative removal of related pollutants.According to the actual emission of a 330MW unit in a coal-fired power plant,combined with the local environmental protection requirements and the site layout of equipment,the paper makes a comprehensive comparative analysis on the technical route of colored smoke plume treatment of the unit,then determines to adopt the"end"collaborative removal technology,combined with flue gas condensation+MGGH.Finally,the relevant technical parameters are determined and the original equipment is transformed.Due to the increase of some equipment in the limited space of the original duct,in order to meet the requirements of ID fan output and equipment performance,the CFD simulation software is used to simulate the main equipment.By optimizing the equipment flow field,the system pressure drop is reduced and the equipment performance is effectively improved.The main conclusions are as follows:1.The integrated technology of colored plume treatment has a significant effect on eliminating the white plume.In the design,the flue gas at the desulfurization outlet is cooled and condensed from 48℃to 43℃and then heated to 58℃through the flue gas reheater.Test results show that the moisture of flue gas at the inlet of chimney is between 7.92%-8.23%,which can ensure the complete elimination of white plume with an atmospheric temperature above 12℃and a humidity below 60%,which is basically consistent with the theoretical calculation.2.The integrated technology of colored plume treatment has a significant effect in the collaborative removal of SO₃ and other condensable particles.CEMS SO3 readings are below 2mg/Nm3,which successfully eliminates blue smoke.When the temperature of flue gas at the outlet of the cooler is lower than 95℃,the effect of ESP on SO₃removal is obvious:SO₃emisisonat the LLT ESP outlet is 33.38 mg/Nm³,while after the condenser is put into operation,the SO₃ emisison at the inlet/outlet of the condenser is 8.07/4.46 mg/Nm³respectively.The removal of SO₃ can be effectively realized by a combination of low-temperature ESP system,high-efficiency wet desulfurization,flue gas condenser and wet ESP,The SO₃ concentration atthe chimney stays stably within2 mg/Nm³for a long time,the effect of eliminating blue plume is significant.3.Three dimensional simulation calculation and optimization of flue gas cooler,reheater,condenser and flue gas inlet and outlet are carried out by CFD simulation software,and the guide plate and anti-vibration partition board are set as a whole,which can reduce the pressure drop of equipment and eliminate the hidden danger of equipment vibration and provide theoretical support for the efficient operation of the system.The relative RMS deviation of air distribution for original flue gas cooler,reheater,condenser was optimized from 0.553/0.39/0.24 to 0.297/0.25/0.2 respectively.The test results show that the uniformity of velocity field distribution of each equipment meets the design requirements,the operational pressure drop of the equipment is within the design value,and the equipment is safe without vibration,which ensures the performance of heat exchanging and a safe operation.Through theoretical analysis,process demonstration and project implementation,the paper proves the feasibility of the integrated technology of colored plume control,which is,through the low-temperature flue gas treatment system,wet desulfurization tower,wet electrostatic precipitator and flue gas condensation/reheating technology the elimination of colored plume and collection of condensable particles could be effectively realized.