The Optimal Design Of SCR Metering Pump And Experimental Research Based On The Check Valve

In response to the Ⅳ emission regulations and above,the advanced diesel after-treatment technology is necessary.SCR(Selective Catalytic Reduction)technology route was agreed that can meet the Ⅳ and above the emission regulations.In view of the domestic application of SCR technology problems,such as lower measuring accuracy and repeat precision of SCR system,SCR metering pump system air check valve crystallization problem,this paper puts forward an optimized design scheme based on one-way valve of SCR metering pump.In the research and analysis at home and abroad a variety of SCR add blue(pure solid urea and urea aqueous solution made of pure water according to the ratio of 32.5% diluted)injection system design concept and structure characteristics,the paper puts forward the SCR adblue injection system design scheme——the air auxiliary SCR adblue injection system of metering pump.The SCR is done according to the requirement for metering pump type selection and design of main components,chose the quality of check valve ball is 0.15 g,the pee-tightening force and stiffness of are 0.15 N and 60 N/m,the opening pressure spray check valve is 190 kpa.Based on AMESim(Advanced Modeling Environment for Performing Simulation of Engineering System)software Modeling and Simulation of the SCR metering pump designed and the different parameters of SCR metering pump flow characteristics of the simulated graph proves that the design of the SCR metering pump has good dynamic response characteristics and measuring precision.This paper conducted for SCR researches on the crystallization of the metering pump pneumatic valve,through the analysis of SCR metering pump pneumatic valve crystallization,this paper analysis different air check valve check valve materials,different arrangement type,the structure of the different structure of the mixing chamber and air pressure regulator on the analysis of the influence of the air check valve crystallization,chose the dual channel pressure regulator and the solution of the oblique way,through the test,the SCR after the optimization design of crystallization of the metering pump no air check valve.The paper also has carried on the SCR add blue injection system bench test to verify the feasibility of the design,through to the SCR metering pump injection volume calibration,verify the SCR metering pump has good injection accuracy and repeat precision.SCR metering pump and the design of the emissions targets for the Ⅴ emission standard SC4H(180 HP)engine matching test,did not detect the leakage of urea in tail gas,meet the Ⅴ emission regulations.