Design And Simulation Of Ship Sewage Treatment System Based On PLC

With the accelerated process of the global economy and the increasingly emphasis on the marine environmental protection,people are increasingly demanding of the impact of shipping on the marine environment.Against this background,the work of shipping industry anti-pollution has been on the agenda.From the perspective of the ship sewage treatment,this paper analyzes,compares of the advantages and disadvantages of different processing devices to determine the type of device can be widely used in most of the ships.According to the selected type of device,it analyzes the solving process of the real sewage treatment and optimizes the existing method of sewage treatment with PLC,which makes the device not only satisfy the rule of sewage treatment but also have the higher efficiency.Then the automatic control of sewage treatment is achieved.Finally,with the simulation and communication technology,the paper develops a sewage treatment system that can simulate the actual process of sewage treatment.The paper has introduced the operating principle of the different devices in the ship sewage treatment system,such as the operating control of aeration fan,the start-stop automation of emptying pump,the auto-control of the sludge discharging and so on.And it provides the theoretical basis for the programming of PLC and the simulation.Therefore,the correct controlling procedure can be developed with different controlling theories.Then,the sewage treatment mathematical models of different devices and processes are created,such as the models of centrifugal pumps,tanks,liquid level,centrifugal fans and restricting elements and so on.And the paper develops the real sewage treatment simulation interface on the basis of the selected method of sewage treatment.Finally,the simulation result is operating correctly with dynamic presentation via the communication technology.The final result indicates that the developed simulation system operating smoothly and successfully simulates the real sewage treatment with a friendly interface,which has the most important reference value for the future development and the research of the sewage treatment system in ships.