生物柴油混合燃料对柴油机VOC排放的影响

由于其属性与柴油的相似性以及在废气排放和生物降解方面的有利特性,生物柴油被越来越多的应用。为了更好地了解生物柴油,本研究将探讨与普通柴油相比,生物柴油混合燃料对柴油机废气中VOC(挥发性有机化合物)排放的影响。每种燃料依据美国的瞬变周期协议以0-80,000km行驶里程为周期进行几次废气排放测试。通过使用热脱附管收集稀释废气中VOC样品,然后由GC/MS(质谱仪)系统分析。在B20和柴油燃料中,分别识别并量化出22种和47种化学物质。整个VOC排放量在B20燃料和柴油中的范围分别是32.4-71.6mg kW/h和49.6-183.7mg kW/h。个别的VOC排放范围是0.1-29.8mg kW/h(B20)和0.1-93.6mg kW/h(柴油)。就危害商数方面而言,个别VOC健康风险在B20燃料和柴油燃料中的范围分别是0.01-1.13和0.01-22.79。B20燃料具有低得多的VOC排放量,平均减少了61.2%;相应地,VOC的潜在臭氧总量较低,减少了64.0%。另外,B20燃料也显示出健康隐患方面的降低。因此,就VOC排放而言,柴油机使用生物柴油比较有利。     

甲醇柴油燃料的试验研究

云内4100QBZL柴油机分别采用MD20、MD10、MD5甲醇柴油与0#柴油时,对其动力性、经济性、排放性等方面进行了研究。试验表明,随着掺烧甲醇添加量的增加,动力性略有下降;采用甲醇柴油在经济性上要优于柴油;尾气中的CO、HC排放都下降明显;在甲醇添加量超过20%时,出现增加甚至超过柴油工况的情况,而随着甲醇添加量的增加,NOx呈现先增加后减小的趋势。     

柴油添加剂对柴油机排放的影响

采用一台增压中冷柴油机,分别燃用0号柴油和按5%、10%、5‰比例添加某燃油添加剂,对发动机气态污染物排放特性进行对比分析。外特性工况,各加剂燃油THC排放有升高,且随掺比增加呈现正相关趋势,NO_X和CO排放没有明显差异。小负荷工况时,随转速升高,各加剂燃油CO排放差异变大,但没有明显改善,NO_X排放差异性较小。中高负荷时,各加剂燃油对CO排放没有明显差异,NO_X排放有一定改善。部分负荷时0.5%添加剂使得THC排放恶化明显。     

葵花籽油-柴油混合燃料的排放特性试验研究

以S195柴油机为试验机型,在柴油中掺入10％、20％和30％体积比的葵花籽油配置成混合燃料,进行台架试验,测量并分析排放试验数据.试验表明葵花籽油-柴油混合燃料能改善缸内燃烧,降低NOx和碳烟的排放.     

甲醇裂解气发动机非常规排放的测试与分析

选择以气相色谱技术及质谱检测技术为基础的发动机尾气采集系统和利用气相色谱分析系统的采样方法、载气流速、柱温等参数,证明该系统完全可以对甲醇裂解气发动机排气中的非常规排放物进行精确的检测分析。     

柴油/乙醇混合燃料对发动机排放性能分析

介绍了在柴油中混合不同比例的乙醇对柴油机CH、NOx和碳烟排放的影响.采用柴油/乙醇制成不同比例乳化燃料在一台直喷、增压、中冷柴油机上进行试验.试验结果表明随着乙醇掺烧比例的增加,HC排放逐渐的增加,尤其在小负荷工况范围内,HC排放恶化严重;NOx排放在小负荷工况下有所改善;发动机碳烟排放逐渐的降低.     

甲醇裂解气发动机进气系统研究

将甲醇裂解气作为普通汽油发动机的代用燃料时,为了让甲醇裂解气发动机可以正常工作,根据流体力学原理,重新设计了甲醇裂解气发动机专用混合器.为了防止裂解气发动机工作时出现爆震,设计制作了一套爆震传感器及其放大电路用以驱动加浓燃油喷射系统.新结构的混合器可以使空气和工作燃质更好地混合,当工作燃质不足时还可以利用燃油喷射系统加浓燃质,使甲醇裂解气发动机正常工作.     

高原地区含氧混合燃料对小型柴油机性能及排放的影响

在一台ZX195型单缸柴油机上,通过在柴油中添加甲醇含氧燃料及适量的添加剂,研究了在高原地区常用工况下含氧混合燃料对柴油机性能及排放的影响。试验结果表明,含氧混合燃料可以有效改善柴油机的烟度排放,在大负荷下尤为明显。而对动力性影响很少,经济性得到改善。     

甲醇燃料汽车排放特性研究

对国家甲醇燃料汽车示范车队道路运行情况进行了长期跟踪研究.结果表明：甲醇汽车动力性良好;运行经济性能优于汽油车辆;HC排放平均降低45.36%,CO排放平均降低75.85%;甲醇燃料的非常规排放物甲醛及未燃甲醇含量均高于汽油,但经尾气催化转化器后大部分消除.     

柴油掺烧生物柴油在高速电控共轨柴油机的性能与排放研究

以玉柴4D20柴油机为试验机型,在柴油中掺入10%、20%和30%体积比的大豆生物柴油配置成混合燃料,进行台架试验,测量并分析性能与排放试验数据。试验表明,燃用生物柴油混合燃料动力性稍微有点下降,燃油消耗率增加;排放方面可以大幅度降低碳烟的排放,但是NOx稍微增加。     

The influence of engine oil on diesel exhaust emissions

Increasingly stringent emission legislation, together with the requirements for improved diesel engine performance, such as fuel economy, friction reduction, and extended drain intervals, have led to attention being focused on engine oil quality. The use of low‐friction engine oils can improve engine fuel efficiency and lead to a significant reduction of gaseous emissions. Therefore, engine oil is of importance when considering engine design parameters. This paper describes a study of the contribution of engine oil to diesel exhaust emissions. The investigations have shown that diesel engine particulate emissions as well as hydrocarbons and NO_X emissions depend on the lubricant oil properties, in particular on the sulphur content, volatility, and metal content.     

电控单体泵柴油机燃油喷射控制策略

电控单体泵由电控泵喷嘴发展而来,由于在电控泵与喷油器之间加入了高压油管,使电控单元从发出喷油信号到燃油喷入汽缸的时间延迟加长.针对该特点,以及考虑到程序计算时间、电磁阀响应特性等因素对喷油正时的影响,设计了喷油正时控制策略.试验结果表明,电控单元可按喷油正时控制策略准确地、柔性地控制喷油正时和喷油量.     

基于PLC的柴油机重油动态乳化过程控制系统

根据船舶柴油机重油动态乳化过程的特点,设计了将PLC控制的方法应用于重油动态乳化过程的控制系统,介绍了系统的工作流程、功能特点以及系统硬件和软件设计,并给出了部分实验核心程序。实验结果表明,该系统对掺水率的控制精度可达1%以上,燃油消耗率平均降低7.8%。     

Combustion and emissions of the diesel engine using bio-diesel fuel

The combustion and heat release of engines using diesel fuel and bio-diesel fuel have been investigated. The results illustrate that the combustion happens in advance and the ignition delay period is shortened. The initial heat release peak declines a little, the corresponding crankshaft angle changes in advance, and the combustion duration is prolonged. The economic performance and emission features of diesel engines using diesel fuel and bio-diesel fuel are compared. The results also show that the specific fuel consumption of bio-diesel increases by about 12%. The emissions, such as CO, HC, and particulate matter decrease remarkably whereas NO _x increases a little. __________ Translated from Journal of Jiangsu University (Natural Science Edition), 2006, 27(3): 216–219 [译自: 江苏大学学报(自然科学版)]     

柴油机电子油门传感器的线性优化

理论上分析了影响电子油门传感部件线性度的关键因素：电子油门传感部件径向磁场磁感应强度.通过对影响电子油门传感部件径向磁场磁感应强度的各个因素：初级线圈长度和半径、偏心圆盘偏心矩和半径、初级激励电压的分析.提出了各个因素优化来提高电子油门传感部件线性度的方法,得出了电子油门传感部件最佳线性度的性能参数.并对与其匹配的信号调理电路进行了最佳线性优化.依据柴油机电子油门控制系统模拟实验装置平台,对优化后的油门传感器进行了柴油机加减负荷模拟实验,并进行了误差分析.结果表明：柴油机电子油门控制系统的动态响应达0.23 s,线性度为0.38%,完全满足电子油门控制系统正常工作的要求.     

基于模型的共轨柴油机主喷油量控制算法研究

针对目前高压共轨柴油机电控系统开发周期较长以及开发成本较高的问题,通过研究基于模型的软件开发流程,在Matlab/Simulink环境下建立了高压共轨柴油机主喷油量控制算法模型,其中包括烟度限值控制模型、启动油量控制模型、怠速油量控制模型、怠速PID控制模型以及油量脉宽转换模型;对控制算法模型的关键MAP图进行了标定以验证该控制算法模型的有效性,并在使用INCA标定软件建立监控和标定的发动机试验台架上进行了一系列试验。试验结果表明,发动机启动过程迅速,且正常工况下转速稳定,并能根据环境情况和发动机的当前需求自动调节目标油量;该控制算法能够较好地满足发动机起动、怠速以及正常工况的控制需求。     

变系数PID控制在柴油机调速系统中的应用

针对具有非线性、时变、非稳定等特点的柴油机电液调速系统提出变系数PID控制方法。该方法在充分利用传统PID控制器优点的基础上,利用误差变化的特点,采用变系数方法来构造PID控制器结构。仿真结果表明采用变系数PID控制方法进行控制,最大超调量、上升时间、峰值时间都达到比较满意的控制效果。     

Real-time diagnostic system using acoustic emission for a cylinder liner in a large two-stroke diesel engine

Damage that originates from abnormal wear in the cylinder liner of marine diesel engines causes a considerable loss of property to manage shipping vessels. However, because multiple factors contribute to such damage, it is difficult to anticipate the damage that is caused by abnormal wear, such as scuffing, by investigating the mechanism of abnormal wear. Therefore, several methods have been explored for predicting the abnormal wear between the cylinder liner and the piston ring in marine diesel engines. For example, methods that are based on an analysis of the temperature, vibration, or cylinder drain oil have been researched. However, the response time of such methods is too slow for an operator to have enough time to promptly cope with severe damage. The implementation of such methods also requires prior modifications to the engine, which cost time and money. To overcome such problems, methods of prediction that use AE (acoustic emission) have been widely investigated. Studies on the relationship between abnormal wear and AE signals have demonstrated that severe damage is preceded by a change in the RMS value of AE and the FFT amplitude of a specific frequency. However, previous studies on the AE technique were based on the offline analysis of stored data due to their focus on the relationship between abnormal wear and AE signals. Thus, for direct implementation of the AE technique in industry, a real-time diagnostic system is needed. This paper focuses on the development of a real-time diagnostic system for analyzing high speed AE signals and examining the wear status of cylinder liners in marine diesel engines.     

Performance development target setting of passenger car diesel engine

Setting engine emission targets to meet diesel car requirements is particularly important in engine performance development phase. Many researches are focused on associating vehicle performance with engine targets, but most work is done by testing, which is time and cost consuming, furthermore, the relationship of vehicle and engine will change when either engine or vehicle changes. A GT-Drive model to simulate New European Driving Cycle (NEDC) for passenger car is developed and calibrated by testing data, model precision is controlled within 5%. Time distribution of engine operating conditions when car running NEDC cycle has been analyzed, 10 critical major engine operating points are summarized according to running time proportion. Emission of NOx and smoke control regions containing these 10 points for target engine are set. Vehicle emissions are simulated and evaluated during engine development after engine performance test data are got, and engine combustion system layout and calibration are adjusted until vehicle targets are met. Vehicle is tested in chassis dynamometer finally, the testing results show a good agreement with the simulated results with an error of less than 5%, which proves that the emission value exchange of vehicle and engine is reliable. Performance target decomposition method for passenger car diesel presented can greatly shorten the development cycle and save costs.     

柴油机供油提前角对曲轴主轴承动载荷的影响

针对柴油机曲柄连杆机构整体模型,采用多体动力学方法建立柴油机曲轴动力学模型,分析了不同供油提前角下曲轴主轴承动载荷的变化,仿真过程中对曲轴进行柔性处理,同时计入油膜的动力润滑作用,将不同提前角下曲轴主轴承载荷进行比较,得出供油提前角对柴油机的影响规律。