Research On Dehumidification Technique Of Moisture Vapor Phase Change

This topic relies on the desulphurization flue gas whitening project of Liaoning Zhongke Environmental Protection Co.,Ltd.In view of the problems existing in the existing widely used flue gas whitening technology,such as large energy consumption and large complex volume of equipment,a solution to dehumidification and self-dehumidification of water vapor phase change wet smoke gas is put forward,and a set of water vapor phase change wet flue gas dehumidification control system is studied and realized.The following work has been done for this control system.The thermodynamic process of dehumidification of water vapor phase change is studied.Combined with enthalpy and humidity diagram,the dehumidification mechanism is analyzed and the optimum working point(that is,smoke exhaust temperature)in the dehumidification process was determined.According to the influencing factors of the best working point,the dehumidification process of wet flue gas with water vapor phase change is determined,and the control strategy is worked out.The smoke exhaust temperature is adjusted by the PID closed-loop control system,and then the control system scheme is determined.The influencing factors of wet flue gas dehumidification are studied.According to the parameters affecting dehumidification,Aspen Plus software is used to study the effect of air temperature and humidity on dehumidification,and the feasibility of dehumidification strategy is verified step by step.The best working point is solved.By establishing three conservation equations,fitting the formulas of moisture content and temperature,and fitting the formulas of saturated water enthalpy and temperature,the optimal working point calculation model is established.In the process of modeling,the number of unknown numbers is more than the number of equations,and the iterative search algorithm is used to solve the optimal working points.The boundary atmospheric temperature,humidity,saturated wet flue gas temperature and wet smoke volume reflect the temperature,water evolution and ventilation volume when the optimum working condition is concerned.Design the control system.Aiming at the practical application,according to the dehumidification control scheme of water vapor phase change wet flue gas,a control system based on Siemens S7-300 PLC and WinCC is constructed.the control system structure is divided into monitoring layer,control layer and field equipment.The optimal working point is solved by compiling VBs global script from the upper computer.The control of exhaust smoke temperature under different air temperature,humidity and saturated wet flue gas temperature environment is realized by PID simulation,and the best dehumidification effect of wet flue gas is achieved.