Design And Numerical Study Of Pressure Boost Electronically Controlled Low Speed Marine Diesel Engine Injector

The precise injection timing,variable injection pressure and controlled injection flow rate are needed about the fuel injection system for meeting the stringent Tier Ⅲ emissions regulations.As the key component of the FIE system,the electronically controlled injector is the only way to achieve this target.This paper is focus on the design and development of an electronically controlled injector based on the project about investigation of the critical technology of the CR and ECS system of low speed marine engine which is supported by government and in order to close the technology gap from the professional FIE system supplier and fill in the blanks of this area.A technology route that will be used fuel boosting for injection is finalized by the development of the FIE system in the market,the requirements of the FIE system about the marine engine and the situation about domestic manufacture and supply.In this context,some basic structural parameters of the injector were obtained with calculation and a Parker DF plus valve was used to control the fuel boosting process.A simulation model of HHM340 injector was made by AMESim and the basic structural parameters of the injector about the concept design have been validated through simulation.The result showed that the parameters can fulfill the requirements of FIE system demanding,the cycle injection quantity had a good consistency,the injection pressure could be adjusted by servo oil pressure setting and the injection flow can be controlled fully flexibly(could achieve rectangle injection、boost injection、double injection,etc.).After the concept design,the engineering design of the injector was realized and a set of drawings have been finished,then the drawings were sent to factory for machining.A test bed has been designed and established based on the characters of the electronically controlled injector.This test bed was made up of mechanical parts which have servo oil supply、low pressure fuel supply、high pressure fuel、injectorand electronic parts which have the driving unit of pressure control valve of servo oil pump outlet、fuel boosting valve、motor,etc.the sensors output collecting、display and the running state of the test bed monitoring、the emergency stop and other safety protecting measures.