Temperature And Acidity Control Of Outlet Flue Gas In Semi-dry Reactor

As the improvement of urbanization and the quality of people's livings, the amount of the garbage output increased at an alarming rate every year in our country. Municipal solid waste was listed as the first of the three major environmental problems which need be resolved emergently. Chinese government has included waste disposal and harmless systems in the < Precedence projects of china agenda 21^st >.Under the circumstance of the land resource gradually decline. Rubbish resources recovery,quantitative reduction,disposal harmless was proposed by government. To maximize the realization of Rubbish resources recovery,mass reduction,disposal harmless. And minimize the occupation of land resources. So in recent years waste incineration technology has been developed rapidly, WTE plants have been vigorously promoted over the country.Flue gas treatment system is the key process of the municipal solid waste incineration, and the only way to approve the regulation of pollution emission. The success of incineration and flue gas treatment dependent on reliable and steady automatic control .According to this problem, we propose the control of scrubber outlet flue gas temperature and acidity as my articleIn the process of semi-dry flue gas treatment system, thy top two control process, the scrubber outlet flue gas temperature control and acidity control, it's difficult to get the ideal result. As the long control path and slow respond of temperature measure, the saturation is very serious since the lag of temperature control. Because the waste are complex and the acidity 's big change of inlet flue gas, it's hardly reduce the flue gas acidity quickly under the jamming of flue gas, and the emission often exceeds the standard by normal control method. In additional, the gas flue temperature and acidity control reaction both take place in the scrubber, the reactants both are lime slurry. So the two control process will interfere each other. According to this problem, I propose to take scrubber outlet flue gas temperature and acidity as my research subject.Deeply analyses the control nodous .flue gas temperature of scrubber outlet adopts cascade control to improve respond performance and anti-saturation. Acid gases treatment adopts feedforward and feedback rate control methods. Taking the scrubber inlet gas acidity as feedforward control system input. When the acidity change rapidly due to the waste component change, the feedforward system can react immediately to decrease the acidity. In order to coordinate the gas temperature control and acidity control, we take different manipulate variable to the same primary variable to achieve our goal. Temperature control system control the total flow of lime slurry, and the acidity control system control the density of lime slurry. Both systems are able to automatic control steady.The result of modeling and simulation proved that the system would be good performance and practicality in application.