Investigation Of EGR Electronic Control Technology On Low-Speed Marine Diesel Engine

With 2021 approaching,the Tier III standard is about to be implemented in the NOx emission control area,and the reduction of low-speed two-stroke marine diesel engines is imperative.Due to low retrofit cost and obvious effect of reducing NOx emission,Exhaust Gas Recirculation(EGR)technology has attracted researchers’ attention.In China,there are many scholars have conducted theoretical research,but no relevant experiments are tested.Based on the analysis of a large number of domestic and foreign literatures,the subject takes the 6EX340 EF diesel engine EGR system as the research object.The STM32F103VET6 microcontroller as the core control chip are selected to design a practical EGR control system and give the control law.This paper has completed the hardware and software design of EGR control system of marine low speed machine.The main contents are as follows:First of all,this paper analyzes the structure of the EGR system of 6EX340 EF diesel engine,transforms the intake and exhaust pipe,and determine the position of the change over valve,cylinder bypass valve,exhaust gas valve,shut-down valve,fan and water treatment system.Then,the single-chip microcomputer system based on STM32F103VET6 chip was designed.SCM system includes information acquisition part,CAN communication circuit,digital input and output circuits,and so on.Second,based on the LabVIEW software,the host computer interface is designed.The interface is mainly designed to detect and record important parameters,manual control of EGR system,parameter calibration function and alarm prompt function.According to the logical relationship between the components of the EGR system and the control method of the fan and the valve,the control strategy of the lower computer of the EGR system is designed.Finally,the EGR control system simulation test and test were completed.Using PLC to simulate test environment and sensor feedback signals,the interface of EGR control system is completed manual and automatical control.And EGR test is completed on 6EX340 EF diesel engine.The test results show that the EGR control unit can fulfill the requirements of the low-speed two-stroke diesel engine test and lay a foundation for independent research and development of the low-speed diesel engine.