The Application And Debugging Of DCS In FGD System Of Thermal Power Plant

At present,The main use of China's power plants' power is coal-fired.While the concentration of sulfur dioxide produces in the coal-fired process is low,but the total is great.If we don't process before it emissions,it will influence the quality of the atmospheric environment,causing acid rain pollution.Therefore,controlling the SO2 exhausting amount in the coal-fired power plants is the key point to control the acid rain.In this article an example of the Tianjin Dagang power plant FGD control system will be studied.Based on the research of flue gas desulfurization control in power plants,it studied the technological process and working principle of Flue Gas Desulfurization System.At the mean time,DCS realization of flue gas desulphurization control system is also researched.The major work and application study that this thesis carried on are:1 In order to study the wet limestone-gypsum FGD system in a coal-fired power plant,a simple introduction of the technological process of Flue Gas Desulfurization System was given.And then this article detailed flue gas system,absorber system,the limestone slurry preparation system and gesso dewatering system.2 The chemical reaction of SO2 and absorber were analyzed,which was mainly to understand chemical reaction of desulphurization process,including Absorption reaction,Oxidation reaction,Neutralization reaction,Crystallization reaction and PH control.3 DCS realization of flue gas desulphurization control system was designed.In this part,it first introduced the commonly used three kinds of desulfurization control system,while the design of DCS for flue gas desulphurization control system was in detail.Design includes the composition and the main function of the desulfurization DCS control system.It also detailed the dedign of DAS,MCS and SCS.Besides,the reliability of the control system is also designed.4 A brief introduction of the FGD's adjustment was analyzed by researching the monomer debugging,subsystem debugging,a complete set of debugging and the desulfurization system's 168h commissioning.At the same time,it also told the main problems and solutions met in the two FGD process.After the test of load and the operation conditions during the complete set of start commissioning,Tianjin Dagang power plant FGD control system can be put into use continuously and steadily.In the desulfurization of control,the operation personnel can easily control the parameters with simple operation,ensuring the stable operation of the system and improving the system's security.