【作者】 颜伏伍；

【导师】 柴苍修；

【作者基本信息】 武汉理工大学 ， 机械设计与理论， 2002， 博士

【摘要】 本文通过大量的文献阅读，翔实的分析了车用汽油机排气中有害气体成分的产生机理、影响生成的主要因素、治理排气污染物的主要技术措施，指出这些措施与发动机的其他性能(如动力性、经济性等)的一种折中关系，只有“电控喷射+排气催化转化”是一种机内与机外相结合的措施，是控制车用汽油机排放的主流技术。同时，分析了电控和催化转化技术与车用汽油机进行良好匹配的重要性，并围绕该主题进行了系统深入的研究，具体内容如下： (1) 开发了适合于车用汽油机使用的稀土复合型汽油机排气催化剂，进行了催化剂配方的研究和制备工艺的研究，进行了催化剂微型评价装置的研制。所开发的稀土复合型催化剂具有良好的性能。 (2) 用ANSYS系统，进行了催化转化器的流动特性研究，获得了催化转化器结构因素对于流动特性的影响规律，该规律可以指导催化转化器的结构设计。 (3) 分析了催化转化器机械破坏的主要原因，提出了针对我国催化转化器的机械性能评价方法，该评价和试验方法已被国家环境保护产品《汽油机排气催化转化器》的技术认定条件(标准号：HCRJ1999-007)采纳。 (4) 通过分析国内外目前的封装方式和对催化转化器垫层的特性进行研究，提出了催化转化器的“悬浮封装”技术，采用该技术可以较好的解决汽油机催化转化器的机械可靠性问题。 (5) 建立了针对化油器式车辆的“电控补气+三效催化转化器”系统，通过采用双回路电控补气可以为三效催化转化器建立良好的工作条件，较好的解决了化油器式汽油机动力性、排放(同时降低HC、CO和NOx)之间的矛盾。 (6) 开发了一套电控匹配开发系统，本系统已建立的电控燃油喷射系统基础上，添加对电控单元控制参数的实时控制、修改和对发动机运转状态的监视。借助双端口RAM，可实现电控燃油喷射系统与匹配开发系统之间的无缝接口，使电控喷射系统开发完毕后，匹配开发系统中的电控单元控制程序经过少量修改后就可以移植到生产型电控单元中。采用该匹配开发系统，在单缸汽油机上进行了初步匹配研究试验。 武汉理工大学博士学位论文门）对于催化器的性能与电控系统的匹配进行了研究，所开发的含铆稀土复合型催化剂可以明显扩大高效工作窗口。（8）进行基于所开发的电控补气系统上的催化器与电控系统的匹配研究，当控制系统调节空燃比在一定范围按照一定频率进行波动时，可以提高催化转化器的转化效率；通过控制氧传感器的比较电压，可以控制催化转化器的工作窗口，实现排放污染物中，HC、CO、NOX转化的最优匹配。（9）进行了催化转化器与排气系统的匹配研究，对于催化剂的布置，提出了“分级净化，逐级推动”的原则；对于载体形式的选择，提出了“金属载体和陶瓷载体复合”使用的原则。这样可以良好的解诀催化转化器与发动机匹配时，排气污染物高净化率与动力性经济性损失小之间的矛盾、快速起燃和结构布置困难的矛盾。（1）在 MK14程序的基础上，开发了基于 Wndows的发动机工作过程模拟计算系统，利用该系统指导催化转化器在排气系统制的结构布置设计，可以节省试验工作量，并可以获得良好匹配效果。更多还原

【Abstract】 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更多还原