| This paper analyzes the forming principle,effecting factors and controlling measures of poisonous gas of exhaust emission from petrol engine for vehicle fully and accurately. After the comparison on the emission control measures,it is clear that there is a trade-off relation between emission control and power,torque,fuel consumption of engine. "EFI+Catalytic converter" is a integration measure of in-engine and out-engine,which is a mainstream technology of emission control for petrol engine for vehicle. At same time,this paper analyzes the importance of well matching of electronic controlling and catalytic converting technology with petrol engine. The main R&D work can be outlined as follows:(1) Working out catalyst for petrol engine which is the compound of rare-earth to noble metal,studying on compounding ingredients and making technics of catalyst,mini-evaluating device having been developed and the catalyst developed having high converting efficiency and long life.(2) The flowing characteristic of catalytic converter having been studied on the base of ANASYS system and effecting factors to catalytic converter flowing having been gotten,which can guide the structure design of catalytic converter.(3) Analyzing the main destroying reasons and putting forward evaluating methods of mechanical performance of catalytic converter,the evaluating and testing methods being adopted by technical certificating condition of products (Catalytic Converter of Exhaust Emission of Petrol Engine)) of national environment protecting(Standard Number:HCRJ1999-007).(4) By analyzing all kinds of encapsulating n- ethods of catalytic converter and researching the mat expanding characteristic of atalytic converter,"suspending encapsulation" method being put forward,and the method being well capable of solving mechanical reliability of the converter.(5) "Electronic controlled bypassing air + Three-way catalytic converter" system used for carburetor petrol engine which"is capable of setting up workingcondition for three-way catalytic converter and can solve the contradiction between emission control (controlling HC,CO,NOx at same time) and power,torque,fuel consumption having been put forward.(6) At the base of EFI,a set of developing and matching system which can control and modify the controlling parameters of ECU real time and monitor the running state of the engine has been developed. Depending on the two-port RAM,this system has implemented no-slot interface between developing ,matching system and EFI system,and the program in the ECU of developing system can move to the ECU of EFI in the actual engine with a little modification. Some elementary matching tests have finished on single cylinder engine by the matching and developing system.(7) Matching between the performance of catalytic converter and electronic system having been researched,and conclusion that the catalyst that is the compound of noble metal with rare-earth including Ce have wide working scope having been gotten.(8) By studying match between the electronic system and catalytic converter on the base of electronic controlled bypassing air system,conclusions having been gotten as follows:higher conversion efficiency of emission have gotten when A/F fluctuates at definite scope and frequency,by controlling the comparing voltage of 02 sensor,the working scope of catalytic converter can be controlled and the matching that can fulfill the high efficiency of HC,CO,NOx at same time has been optimized.(9) By studying matching between catalytic converter and exhaust gas system,the conclusions having been gotten as follow:"purifying step by step and driving step by step" and "mental substrate and chinaware substrate being used in same engine" being the laying principles in exhaust gas system,which can solve the contradiction between high converting efficiency of exhaust emission and small loss of power ,fuel economics, the rapid light-off and laying difficulty of catalyst.(10) On the base of program MK14,numerical simulating syst...
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