Study On SVSC System—A New Type Of Spark Ignition Engine Intake System Without Traditional Throttle Valve

Being a high efficiency method in saving fossil energy,Variable Valve Technology is experiencing an increasingly amount of attention from the engineers around the world,and which being extensively equipped in the automobile engines.Variable Valve Technology can be divided into two series according to its function,Variable Valve Timing(VVT)and Variable Valve Lift(VVL).Those purposes are to increase the intake air mass or to improve the engine efficiency by reducing the pumping loss.Therefore,this paper introduces a new type of engine intake system with the function of realizing valve timing variable in succession,which given name is SVSC system,can also changing the structure of traditional throttle valve.In addition,this paper verifies the engine performance of SVSC system through simulating and experimenting,including the results at every working conditions as planned.Firstly,this paper introduces the structure and the working principle of the SVSC system,including the method of continuous adjusting valve timing and the advantage on SVSC system comparing with traditional throttle valve.In the middle of the paper shows a simulation between the SVSC system engine and the traditional throttle engine depending on GT-POWER software.Before the simulation starts,we calibrate the established model of the traditional engine with our experimental data to make sure the error can be controlled within 5%.Then,after we got the theoretical comparison result between the traditional throttle engine and the SVSC system engine,we make a experiment to test.The test consists of the engine velocity characteristic experiment and the engine load characteristic experiment,each experiment of these two engines are controlled with the same working codition.Base on the test data,we confirm that the SVSC engine may have a little bit bad influence on the engine maximum power performance,not that much,but can do obvious contributions to save the fuel consumption,especially under the middle and low engine condition.From 2000 rpm to 6000 rpm in engine load experiment,a fuel saving up to 10.72% can be obtained at engine speed of 3000 rpm with the load of 1.5kW.This potential decreases proportionally with the load goes higher.However,the SVSC system has definitely significant effect on engine fuel saving.