Design And Test Of Control System For Synergistic Removal Device Of SO_X And PM In Low-speed Marine Engine

In the face of increasingly serious air pollution,in order to fulfill the International Maritime Organization(IMO)emission limits for SO_X,NO_X,PM and other pollutants in the exhaust gas of marine diesel engines,the emission reduction technology of marine diesel engines has been continuously developed.Exhaust gas washing has a good removal effect on SO_X and PM in ship exhaust gas,and it is an effective comprehensive treatment technology for ship exhaust gas.This paper takes the exhaust gas synergistic removal and scrubbing device as the research object,and focuses on the control strategy and fault diagnosis of the sensors and actuators in the scrubbing loop and control components,so as to realize the actual device online operation monitoring,sequence control,online fault diagnosis and closed-loop self-locking.By summarizing the design of the control law,the control system was developed and finally completed the test on the MAN 6S50ME low-speed two-stroke diesel engine.The main contents and research results of the thesis include:First,the principle and device structure of the marine low-speed diesel engine exhaust coordinated removal technology are studied,and the main control parameters and control objects of the system are clarified.In order to reduce the sulfur oxides and solid particulate matter in the exhaust of marine low-speed engine,combined with the technical process,the overall scheme of the control system is designed.According to the characteristics of the device,the control hardware is selected,and the communication transmission is completed through protocols such as PROFIBUS-DP,MPI/DP bus and Ethernet,and the signal distribution,input and output circuit connection and other work are completed.Secondly,according to the technical characteristics and requirements of cooperative exhaust gas removal,the control task is divided into several independent task modules when the program is written,and the system start and stop sequence control,module function control,closed-loop control of operating parameters and operating parameters are written based on TIA Portal.Security procedures,etc.,have constructed the control logic and control strategy suitable for the supply of scrubbing liquid of the tail gas cooperative removal device,the circulating operation of the pump group,and the washing of the scrubber.Again,based on the TIA Wincc software configuration,a good interactive host computer monitoring and control interface is formed,including the control module interface,trend visualization interface and manual control interface.The host computer supports the monitoring records of key operating parameters and operating status of the cooperative removal device,manual start and stop of field equipment,parameter settings and fault alarm prompt functions.Finally,use the soft PLC to simulate the signal transmission of the system to debug the control system of the exhaust gas cooperative removal device.After the hardware integration is completed,the system functions are tested under static and dynamic conditions.After the commissioning,the exhaust gas synergistic removal test was carried out on the MAN 6S50ME two-stroke low-speed machine to verify the exhaust gas removal effect under 25%,50%,75%and 100%stable conditions.The test results showed that the exhaust gas cooperative control system successfully completed the exhaust gas removal test requirements of the two-stroke low-speed engine,and the removal indexes all reached the preset values.This paper studies and designs the control system of the SO_X and PM cooperative removal device in marine low-speed diesel engine exhaust.The research work in this paper can provide support for the development of low-speed engine exhaust after-treatment equipment.