Study On The Regulation And Switching Characteristics Of Compound Supercharging System Of Two Stroke Piston Engine

Two stroke piston engine as a small air force device is widely used,but its power as the altitude increased sharply,ceiling range is relatively small.Turbocharging technology is a very important and effective technique to strengthen and restore the engine power,which can be used in the two stroke engine.As far as possible to improve the engine power recovery ceiling,broaden the altitude range,consider using two composite pressurization scheme.In order to avoid the use of two stage turbocharger engine slow response,lack of energy and exhaust exhaust back pressure rise higher,this paper adopts composite booster(mechanical + turbine)of two stroke engine power recovery under varying altitude related research.According to the related structure and performance parameters of the prototype is established and validated two stroke engine GT-POWER simulation model,based on the combined charging scheme and turbocharger model selection,engine and turbocharging system of varying altitude,composite and composite analysis of two stage supercharging turbocharging system than the distribution of research.The results show that the selected compound pressurization scheme and turbocharger can meet the engine requirements and high power recovery,the engine and the composite supercharging system under different working conditions and altitude,good level,high efficiency running in different conditions and altitude of composite turbocharging system of two stage pressure ratio distribution in the range of 5.5:4.5-4.5:5.5,and with the altitude the rise of high proportion gradually transition from 5.5:4.5 to 4.5:5.5.The composite engine simulation model has been established,respectively analysis using two different pressure ratio distribution scheme of mechanical transmission,two stroke engine,exhaust valve and exhaust valve opening pressure adjustment parameters in steady state conditions regulating characteristics and draw the relevant MAP map.The results show that,by adjusting the related parameters,using two kinds of pressure ratio distribution scheme can achieve two stroke engine high power recovery,the variable compression ratio proportional allocation scheme has more advantages in terms of fuel economy,while the fixed pressure ratio distribution scheme in optimizing the system adjusting,simplified operation etc.advantage.Finally,the establishment of a joint simulation of GT-POWER and Simulink model,based on the composite pressurization control system PID control parameters tuning,the uplink and downlink switching process of the composite turbocharged diesel engine is studied in detail and the corresponding switching scheme,through the comparative analysis to determine the optimal switching scheme.The results show that:the adjustment in the composite turbocharged engine in the switching process of uplink delay 0.2S mechanical transmission ratio and compressor by-pass valve has a smooth transition to the engine power;regulation in the composite turbocharged engine in the switching process of Is downlink delay compressor bypass valve is conducive to the stable operation of the engine.The research results of this paper can provide some theoretical support and analysis basis for the research of the turbocharged reform of the two stroke diesel engine.