共查询到20条相似文献，搜索用时 31 毫秒
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INTRODUCTIONTheinternalcombustionengineisthemostwidelyusedpowermachineryinmodernsociety ,butisalsooneofthebiggestenvironmentalpol lutantsources.Tomeetmoreandmorestringentemissionrequirements,manyadvancedtech niques,suchastheleanburntechnique ,multi valvet… 相似文献
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本文介绍了80C196单片机驱动比例电磁阀,进而对真空调节的EGR系统进行控制,来降低CA498的排放值,特别是NOX的排放值,并对其进行试验.结果表明:采用EGR系统后CA498的排放量下降明显. 相似文献
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对在GW491QE电喷汽油机上燃用不同比例甲醇汽油混合燃料与燃用93#汽油进行对比试验研究,试验结果表明：与93#汽油相比,在中低转速时,混合燃料的燃油经济性有所降低,动力性基本一致;混合燃料的HC和CO排放均明显降低,NOx排放有所改善. 相似文献
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通过对电控汽油机燃油反馈系统中起关键作用的氧传感器的故障实验,在不同工作条件下,研究氧传感器正常工作或模拟失效时对汽油机的各项运行参数及排放物的影响。通过对实验结果的统计与分析,提出基于氧传感器的燃油反馈系统在电控汽油机不同运行阶段的控制方法和控制策略。 相似文献
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To evaluate the performance of newly designed electro-pneumatic valves （EPVs） for the air-powered engine （APE） and study laws of parameters affecting them, a simulation model was established based on the thermodynamics and mechanics theories. Experiments were set up to determine the instantaneous effective orifice area of solenoid valve by the constant volume discharge method. The simulation model was also validated by comparing the measured displacement curve with the simulated displacement curve of the valve in the pressure of 0.16 and 0.49 MPa. Simulation and experimental results showed that maximum working frequency of the designed EPV could reach 30 Hz corresponding to 2000 r/min of engine rotating speed. Based on simulation results, impacts of temperature and pressure of control air on delay time, full opening/closing time and seating velocity of EPV were analyzed. The simulation model could also act as EPV simulation prototype in designing the air exchange control system of APE. 相似文献
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A Model S195 (8.8 kW) single cylinder was used in this study to determine the effect of four operational parameters, i. e.
intake valve close angle, exhaust valve open angle, fuel delivery angle and fuel injection pressure on noise. Single factor
and multi-factor quadratic regressive orthogonal methods were adopted in the experiments to find the relationship between
the four parameters and noise. By means of optimization technique, the optimum operational parameters for two working conditions
of the engine were selected and the test results showed that optimum adjustment could reduce noise by 2–4 dB.
Project supported by Agricultural Ministry of China 相似文献
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基于对现有宏内核工作流引擎局限性的分析,研究并设计了一个基于微内核的工作流引擎.该引擎将活动调度与服务实现相分离,内核层功能独立稳定,从架构上降低了工作流引擎的重构成本和维护难度.采用基于组件的开发技术,降低了系统组件之间的耦合度,提高了工作流引擎的灵活性. 相似文献
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Modeling and multi-objective optimization of a gasoline engine using neural networks and evolutionary algorithms 总被引：1，自引：0，他引：1
José D.MARTNEZ-MORALES Elvia R.PALACIOS-HERNNDEZ Gerardo A.VELZQUEZ-CARRILLO 《浙江大学学报(A卷英文版)》2013,14(9):657-670
In this paper, a multi-objective particle swarm optimization （MOPSO） algorithm and a nondominated sorting genetic algorithm II （NSGA-II） are used to optimize the operating parameters of a 1.6 L, spark ignition （SI） gasoline engine. The aim of this optimization is to reduce engine emissions in terms of carbon monoxide （CO）, hydrocarbons （HC）, and nitrogen oxides （NOx）, which are the causes of diverse environmental problems such as air pollution and global warming. Stationary engine tests were performed for data generation, covering 60 operating conditions. Artificial neural networks （ANNs） were used to predict exhaust emissions, whose inputs were from six engine operating parameters, and the outputs were three resulting exhaust emissions. The outputs of ANNs were used to evaluate objective functions within the optimization algorithms： NSGA-II and MOPSO. Then a decision-making process was conducted, using a fuzzy method to select a Pareto solution with which the best emission reductions can be achieved. The NSGA-II algorithm achieved reductions of at least 9.84%, 82.44%, and 13.78% for CO, HC, and NOx, respectively. With a MOPSO algorithm the reached reductions were at least 13.68%, 83.80%, and 7.67% for CO, HC, and NOx, respectively. 相似文献
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电控发动机故障诊断实验台的设计与研究 总被引：10，自引：0，他引：10
设计和研究了电控汽油发动机故障实验台。实验台能够准确、直观地显示发动机电控系统的数据流和故障码，并能设置故障。试验台为电控发动机的故障诊断提供了方法，汽车维修技术人员可借助该实验台进行数据流分析和故障码分析，来诊断电控发动机的故障，学生也可进行电控发动机理论和故障诊断的学习。 相似文献
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This paper presents a KIVA-3 code based numerical model for three-dimensional transient intake flow in the intake port-valve-cylinder
system of internal combustion engine using body-fitted technique, which can be used in numerical study on internal combustion
engine with vertical and inclined valves, and has higher calculation precision. A numerical simulation (on the intake process
of a two-valve engine with a semi-sphere combustion chamber and a radial intake port) is provided for analysis of the velocity
field and pressure field of different plane at different crank angles. The results revealed the formation of the tumble motion,
the evolution of flow field parameters and the variation of tumble ratios as important information for the design of engine
intake system. 相似文献
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INTRODUCTION The use of dimethyl ether (DME) as an alterna-tive fuel appears to be a promising approach for si-multaneously minimizing NOx and soot emissionfrom conventional diesel engines. The lowself-ignition temperature of 508 K and the high oxy-gen content of 34.8 percent (mass fraction) are twomajor factors characterizing low soot and unburnedtotal hydrocarbon (THC) emissions. Since the firstintroduction of the concept by Sorenson and Mik-kelsen (19… 相似文献
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应用Chemkin化学动力学软件包中的Senkin模块模拟了正庚烷在多孔介质发动机中的燃烧过程．通过修改Senkin程序,结合了Woschni传热模型和多孔介质换热模型,并在正庚烷详细氧化机理中加入氮氧化物的生成机理,将此程序纳入发动机燃烧的零维单区模型．对多种工况参数进行计算,讨论了运行参数对发动机性能的影响．当进气温度、压缩比增大,或过量空气系数降低时,多孔介质发动机着火时刻会明显提前．结果表明：多孔介质对混合气具有预热作用可强化发动机的点火燃烧,多孔介质的初始温度是决定压燃点火的决定性因素． 相似文献
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This work investigates the effects of exhaust gas recirculation (EGR) and operation parameters including engine speed, equivalence ratio, coolant-out temperature, and intake charge temperature on the basic characteristics of a single-cylinder homogeneous charge compression ignition (HCCI) engine powered with reformulated iso-octane fuels. The running range of iso-octane HCCI engine can be expanded to lower temperature and more load by adding di-tertiary butyl peroxide (DTBP) in the fuel. The combustion timing advances with the increase of DTBP concentrations, coolant temperature and equivalence ratio. The effects of EGR on the combustion and emissions are remarkable when the EGR rate is higher than 25%, and the combustion phase is sharply postponed and the UHC and CO emissions deteriorate. The intake charge temperature has a moderate effect on combustion and emissions when it is lower than 35°C; but the combustion timing advances, the combustion duration shortens, and sometimes it leads to knock combustion when the intake charge temperature increases to above 35°C. 相似文献
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柴油机在运转过程中气阀间隙会发生变化,气阀间隙对柴油机的动力性、经济性有很大影响,合适的气阀间隙有利于柴油机的持续、稳定、高效运转。这就要求船舶轮机员定期对气阀间隙检查和调整。 相似文献
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设计了一种应用于传统非可变配气正时的发动机进气系统的固定式单向阀.将该阀安装于发动机气缸体与化油器之间,在中低转速下可阻止已进入发动机气缸内的混合气发生倒流现象,从而能有效地降低传统发动机的燃油消耗率.介绍了单向阀簧片的3种运动形式和对应的影响因素,分析了簧片的设计要求,重点研究了簧片的运动规律,建立了所设计的单向阀簧片的运动微分方程式,并运用Matlab编程求解出簧片的理论固有频率,为单向阀的簧片的形状和限位板高度等的设计提供参考和依据. 相似文献
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为满足生产线上对点火器进行快速、准确检测的要求,采用单片机控制驱动电路和执行机构,模拟发动机实际点火工况,对点火器的各项指标进行检测.运用该方法研制了点火器检测系统. 相似文献
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为使发动机监控系统中数据的显示和分析更直观，使用PictureBox控件和Timer控件，可以解决实时曲线显示问题，具体介绍了绘制实时监测曲线的程序设计方法． 相似文献
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为了将推理与文本检索有效融合起来,提出了一种包含多类型查询的语义搜索引擎体系结构,在此基础上设计并实现了语义搜索引擎系统Smartch.Smartch基于合理的推理流程和图形化定制过程,提供4种形式的搜索服务,分别是基本搜索、概念搜索、图形化定制搜索及关联关系搜索.实验结果表明语义搜索引擎Smartch和传统搜索引擎相比,在本体推理的基础上,查全率和查准率上有一定的提高,图形化定制查询可准确定位用户需查询的概念,关联关系搜索可发现概念之间存在的复杂关系,Smartch实现了一定程度的智能搜索. 相似文献
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The negative valve overlap (NVO) strategy of HCCI operation was experimentally investigated on a gasoline HCCI engine operated with variable valve timing in association with the addition of diesel fuel. The experimental results show that, by using gasoline and diesel blended fuels, the required NVO interval for suitable HCCI combustion under a given engine speed and a moderate compression ratio condition could be reduced, and the HCCI combustion region was extended remarkably without substantial increase in NO, , emissions under a given inlet and exhaust valve timing due to the improvement of charge ignitability. In addition, the possible scale of NVO was extended. A substantial increase in the lean limit of excess air ratio and the upper limit of load range can be achieved because of higher volumetric efficiency, resulting from the decrease in the required NVO and the presence of less residual gases in cylinder. 相似文献