Research And Implementation Of The Denitration System Based On Selective Catalytic Reduction

With the development of economy，environmental problems have become prominentincreasingly，especially in recent years．The most important reason is that there is no strictcontrol for the emission of the air pollution．Among all of the pollution gases，nitric oxideaccounts for a large proportion． Nitric oxide mainly comes from the emissions of thefactory which regard coal as the energy．When nitric oxide emissions is discharged intothe air，it will bring a variety of chemical reactions which can cause the acid rain．People’sdaily life and the development of the social economy will be hampered．So it is necessaryto control the emission of the factory．Firstly this paper introduces the denitration process which is called selectivecatalytic reduction (SCR)．It has many advantages such as simple process，low reactiontemperature,，low cost，and high efficiency．Secondly we analyzed the principle and thefunction of each subsystem in detail．Through the careful comprehensive comparison，weconfirmed that the selective catalytic reduction method is reasonable and feasible in thetreatment for the gas pollution．In this paper, through the study on the selective catalytic reduction of stock process，we determine the control selection of Siemens S7-300PLC as the controller to completethe plenty of function on the parameters such as temperature,pressure and liquid level．Allabove，we have achieved the purpose to make the evaporater to be automatic control．Inthe fact that we have achieved the goal to make the pressure tank to be automatic， wecome to a scheme to adjust the amount of ammonia spray by the stock efficiencysetting．This method can not only hold the denitration efficiency，but also reduce the lag ofthe system in a certain extent．And it also can optimize the system．Using WinCC softwareto configuration， the computer can show the important parameters to us such astemperature，pressure，liquid level，the signal of the valve and the motor．The operatorcan master all of the equipment by the analysis of these parameters．On all aspects of theworking state of the judgment，the operator can make the system safe and efficient． Through the method of selective catalytic reduction for the flue gas denitration，theefficiency can reach more than85%，which can meet the national emission standards．Inthis way， it can make an important contribution to the sustainable development ofenvironment an economy．With the improvement of selective catalytic reduction denitration technology and thepromote of the PLC control function， this method will be used widely in the system tosolve these problems．...