| Recent years with high development of economy and acute aggravation of population of our country, the shortage of water resources becomes serious. The demand on oil increases rapidly which enlarges the need of industrial water and sewage disposal of oil refinery enterprises. Most of refinery wastewater is directly discharged after treatment process, however, the pollution of which will still affect the environment. It's necessary to study on the advanced treatment technology of wastewater, which not only ensure the refinery wastewater recycling to solve the problem of water shortage, but also reduce the pollution of refinery wastewater to the environment and enhance the safety of human life.At first, the refinery wastewater treatment technology and control requirements are described, and then the overall scheme of the control system is confirmed. The hardware system and the control program of the PLC (lower computer) ant the host computer are designed. The main control system configures with Siemens S7-300PLC as the controller and STEP7 for the software development environment. The whole control program is modularized. Lower software development takes STEP7, configures software WinCC6.0 and Protool as the development environment. The hardware selection and configuration of the PLC control system and software development of lower computer software and host computer are finished. The thesis researches on the key points and difficulties of the flow PID control and fuzzy control dosing techniques.In terms of the PLC software development, the control system is programmed at first to determine the control requirements of subsystem. The process of WinCC PC monitoring software development is shown as follows:develop the control operation interface of the wastewater treatment equipment, the status monitor, the parameter and alarm according to the wastewater treatment process. It programs by Protool and sets touch screen in the rack to finish the control operation of the equipment, which makes on-site wastewater treatment process monitoring convenient.Taking further study on wastewater treatment process of refinery enterprises deeply and comprehensively has significant and profound value to energy saving, emission reduction and environment protection in the current situation. |
