Electronically Controlling the System of Preheating Intake Air by Flame for Diesel Engine Cold-Start

In order to improve the cold start performance of heavy duty diesel engine, electronically controlling the preheating of intake air by flame was researched. According to simulation and thermodynamic analysis about the partial working processes of the diesel engine, the amount of heat energy, enough to make the fuel self ignite at the end of compression process at different temperatures of coolant and intake air, was calculated. Several HY20 preheating plugs were used to heat up the intake air. Meanwhile, an electronic control system based on 8 bit micro controller unit (MCS 8031) was designed to automatically control the process of heating intake air. According to the various temperatures of coolant and ambient air, one plug or two plugs can automatically be selected to heat intake air. The demo experiment validated that the total system could operate successfully and achieve the scheduled function.

Hardware-in-the-Loop Research on the Electronic Control Unit for Diesel Engines

A hardware-in-the-loop simulating platform is developed to avoid designing defects caused by the complicated logical structure and multiple-functional buildup of the dectronic control unit（ECU）in modem diesel engines, and to diminish potential damages on components or human exposure to dangers in R＆D en- deavor. This plat-form consists of a computer installed with software Matlab/Simulink/RTW and dSPACE/ ControlDesk; a diesel engine ECU, and a dSPACE autobox which runs a real-time diesel engine model. A typical model of diesel engine with turbocharger and intercooler is presented. Based on this model our research is carried out with a real ECU to test its software control strategies. Results show that by using the diesel engine model downloaded inside, the hardware-in-the-loop platform can simulate diesel engine＇s working conditions and generate all kinds of sensor signals which ECU needs on a real-time basis. So the ECU control strategies can be validated and relevant parameters roughly calibrated.

APPLICATION OF CIRCUIT SIMULATION IN HARDWARE DESIGN FOR ELECTRONIC CONTROL HIGH PRESSURE COMMON-RAIL FUEL SYSTEM OF DIESEL ENGINE

By means of circuit simulation, hardware of electronic control unit （ECU） of high pressure common-rail electronic control fuel system for diesel engine is designed. According to the system requirements for hardware of ECU, signal-processing circuit of variable reluctance （VR） sensor, filter circuit for input signal, high voltage power circuit and driver and protection circuit of solenoid are simulated as emphases. Difficulties of wide scope of VR sensor output signal, efficiency of high voltage power and reliable and swift driver of solenoid are solved. The results of simulation show that the hardware meets the requirement of the fuel system. At the same time, circuit simulation can greatly increase quality of the design, alleviate design labor and shorten design time.

Electronic Unit Pump Diesel Engine Control Unit Design for Integrated Powertrain System

The performance of the electronic unit pump (EUP) diesel engine is studied, it will be used in the integrated powertrain and its multi parameters are controllable. Both the theoretical analysis and experiment research are taken. A control unit for the fuel quantity and timing in crankshaft domain is designed on this basis and the engine experiment test has been done. For the constant speed camshaft driving EUP system, the fuel quantity will increase as the supply angle goes up and injection timing has no effect. The control precision can reach 1°CA. The full injection timing MAP and engine peak performance curves are made successfully.

STRATEGY FOR DIESEL ROTARY ENGINE WITH COMMON RAIL INJECTION SYSTEM

A direct injection low compression ratios diesel rotary engine is designed and studied to find the appropriate application of the electronic controlled high pressure common rail injection system. Current development focuses on the applied fuel injection and ignition strategies, especially concerning the combustion configurations of injectors, ignition source, and combustion chamber. The prototype engine, equipped with Bosch common rail system and high performance electronic control unit （ECU）, is designed correspondingly. Studies show that the integration of a common rail injection system and the main and pilot duel injectors configurations, assisted with glow plug ignition device and flexible ECU, represents a promising approach to improve the potential of the low compression ratios diesel rotary engine. Currently the engine can run at 6 kr · min^-1 steadily and the power is about 68 kW/（4 kr ·min^- 1）.

双升程电控喷油器多次喷射油量波动特性研究

为实现船用柴油机高压共轨系统喷射的柔性和稳定控制,提出一种双升程电控喷油器,基于搭建的喷油器AMESim仿真模型,探究了喷油器不同多次喷射模式下的油量波动特性.结果表明:大升程预喷模式下的主喷量标准差随预喷量的增加先上升后下降,而小升程预喷模式下的主喷量标准差随预喷量呈幅值逐渐降低的波动变化趋势.总体上,在预喷量为161~660 mm^(3)范围,小升程预喷模式在降低主喷量波动程度方面比大升程预喷模式更占优势.预喷射采用小升程喷射模式且预喷量一定时,升程切换延迟为0.2 ms的靴形主喷模式在降低主喷量波动程度方面略优于相同主喷脉宽或相同单次喷射油量的大升程主喷模式.大升程和小升程后喷模式下的后喷量标准差随主喷脉宽和目标后喷量均呈波动变化趋势,且小升程后喷模式下的后喷量标准差波动程度更小.与大升程后喷模式相比,小升程后喷模式在降低后喷量波动程度方面更占优势.

矿山自卸车起动控制过程及故障研究

早期的矿山自卸车一般使用机械泵柴油机,随着人们对发动机排放及油耗要求越来越高,矿山自卸车逐步开始使用大缸径系列电控柴油机。为了了解大缸径电控柴油机的起动过程,以及帮助维修人员更方便的解决电控柴油机起动过程中遇到的故障,本文对大缸径柴油机的起动过程原理进行了详细介绍,并对常见起动困难故障原因进行分类、总结。同时,本文通过故障处理的实例,介绍了大缸径电控柴油机起动故障的处理过程,为维修人员解决此类故障提供了参考。

柴油机电控系统分析与研究

概述柴油机电控技术的发展历程,阐述柴油机电控系统的功能与特点,分析柴油机电控系统的工作原理与控制功能,并对柴油机电控单元、传感器及执行器3个柴油机电控系统的主要组成要素进行研究。

SIMULATION IN THERMAL DESIGN FOR ELECTRONIC CONTROL UNIT OF ELECTRONIC UNIT PUMP

The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit （ECU） design. By means of circuit simulation, the thermal design of ECU for electronic unit pump （EUP） fuel system is applied. The power dissipation model of each power component in the ECU is created and simulated. According to the analyses of simulation results, the factors which affect the power dissipation of components are analyzed. Then the ways for reducing the power dissipation of power components are carried out. The power dissipation of power components at different engine state is calculated and analyzed. The maximal power dissipation of each power component in all possible engine state is also carried out based on these simulations. A cooling system is designed based on these studies. The tests show that the maximum total power dissipation of ECU drops from 43.2 W to 33.84 W after these simulations and optimizations. These applications of simulations in thermal design of ECU can greatly increase the quality of the design, save the design cost and shorten design time

船用柴油机电控系统硬件在环测试平台设计验证

以船用柴油机为研究对象,以dSPACE为硬件基础,从硬件、软件两方面介绍船用柴油机电控系统硬件在环仿真测试平台的设计构建方法,并开展电控系统的基本控制功能和故障诊断功能在线测试验证。测试结果表明,该平台应用于船用柴油机电控系统硬件在环测试可有效降低开发成本、缩短开发周期。

渔用柴油机缸套水余热回收实验研究

为回收柴油机缸套水散逸的热量,提高能源利用效率,这里基于T6138ZLCZu型船舶柴油机搭建了一套余热回收台架,并利用Labview软件和嵌入式开发技术设计了以PID模糊控制方法为核心的温度测控调节平台。实验研究了柴油机功率、冷却水流量和温度对柴油机缸套水余热利用效果及燃油消耗率的影响。实验结果表明:在柴油机负荷为75%,外循环水流量为5m^(3)/h时,燃油经济性较好,此时外循环水进出口温度差最高可达到43℃,可回收缸套水热量为205kW。且系统闭环控制效果良好,超调量较小,具有实际应用价值。

船用柴油机电控喷油器针阀偶件耐久性分析

针对电控燃油喷射系统中针阀偶件的耐久性问题,对某型电控喷油器原理进行阐述,分析针阀偶件可能的失效机理。通过建模与仿真,在机理分析的基础上重点对冲击疲劳寿命进行预测分析。通过试验对针阀偶件失效机理及预测寿命的准确性进行验证。试验结果证明耐久性分析模型有效,可为同类部件的耐久性分析提供参考,并为电控喷油器寿命设计优化提供支撑。

某大缸径高速船用柴油机性能优化

通过优化缸内燃烧过程提高某20缸大缸径高速船用柴油机的经济性。基于现有台架试验数据,通过三维燃烧仿真计算提出喷油器和燃烧室型线优化方案,在单缸机台架上进行优选方案的试验验证和超负荷耐久试验验证。仿真和单缸机试验结果表明:喷油器锥角由150°增大至154°、燃油体积流量由100 mL/s减小至95 mL/s都可提高柴油机性能,且大锥角喷油器优势更明显;台阶型燃烧室型线可改善缸内油气混合和燃烧。100 h超负荷耐久试验结果表明,大锥角喷油器满足可靠性设计要求。

单体泵与高压共轨对农用柴油机燃油消耗率影响的对比分析

通过对农用柴油机电控单体泵燃油系统和电控高压共轨燃油系统加权燃油消耗率样本的统计分析得出,符合第三阶段排放标准要求且进气方式为增压中冷的农用柴油机,电控单体泵燃油系统加权燃油消耗率平均值比电控高压共轨燃油系统加权燃油消耗率平均值高约11 g/(kW·h)。

电子节气门的进化与在氢燃料电池汽车中的应用

电子节气门是汽车发动机电喷系统的关键零部件,围绕着节气门结构与关键产品特殊特性——流量曲线,进行了多次技术创新与迭代。随着以氢燃料等清洁能源在未来汽车应用上的发展趋势,传统的电子节气门技术通过对其自身结构的改进,提高其质量(尤其是流量曲线的精度),提升全闭状态下的密封性和节气门主腔通道与门片材料的耐酸性,促成了氢燃料电子节气门的诞生。

船用柴油机电控单体泵燃油喷射系统一致性浅谈

电控单体泵的主要功能是保证燃油系统喷射特性一致,即定时、定量、定压供给燃油。它体现在单只喷油泵循环喷油量波动率,以及各个喷油泵之间喷油量的一致性。为了实现电控单体泵供油系统喷射特性一致性,可以从两个方面来控制:一是控制燃油系统各零部件加工制造的一致性;二是ECU标定策略柔性控制,补偿喷油泵的制造公差。

大缸径柴油机水泵转速波动影响因素研究

以某V型20缸压裂车的柴油机为研究对象,通过试验研究齿轮传动时曲轴激励、齿轮负载变化、齿轮传递误差对水泵转速波动的影响,并验证了齿轮改为皮带传动的改善效果。研究结果表明,水泵转速波动的主要能量来源是曲轴,曲轴的强迫激励是影响水泵转速波动的主要因素;对称布置的齿轮从动负载差异对水泵转速波动影响较小;受传递误差的影响,对称布置的两侧水泵转速波动水平存在差异,传递误差以静态误差为主,为次要影响因素;齿轮改为皮带传动后,两侧水泵转速波动水平显著降低,达到使用要求。本文的研究成果可为水泵转速波动测试分析、故障分析及改进优化设计提供参考。

矿用防爆柴油机电控系统检测装置的设计方法

矿用防爆柴油机电控系统实际应用时间较短,其检测项目繁多,且基本依靠人工完成。本文介绍了矿用防爆柴油机电控系统的组成以及生产检测流程,并提出了一种自动检测装置的技术方案。该技术方案以煤炭行业标准GB3836为准则,对电控系统的信号输入通道、驱动输出通道及通信通道的进行自动检测,同时集成了常用的生产辅助功能,可以解决生产检测过程中检测设备多、操作繁复以及检测时间长的问题。

柴油机基于缸压的闭环反馈控制技术

为改善柴油机预混合燃烧(PCCI)模式下的燃烧稳定性和分缸均匀性,研发了基于缸压的闭环反馈控制技术.该系统采用由两个控制单元组成的分布式结构,燃烧状态解析单元(iCAT)实时采集发动机各缸缸压-曲轴转角数据,计算缸内燃烧状态指标如平均指示压力(IMEP)、50%放热点(CA50)等,并将结果通过CAN网络发送到发动机控制单元(ECU),ECU据此对喷油参数进行调整,以精确控制发动机的燃烧状态.试验在一台经过系统升级的4缸2.5,L高压共轨柴油机上进行,结果表明,iCAT实时计算精度与燃烧分析仪测量精度基本一致,与燃烧分析仪数据相比,IMEP最大偏差为0.53%,CA50最大偏差为0.33,°,CA,闭环控制后,无论是传统CI燃烧还是PCCI燃烧,燃烧稳定性和各缸不均匀性都得到明显改善.

电控柴油机的在线失火诊断策略研究

为了满足日益严格的排放法规,电控发动机均要求装备OBD(在线诊断)系统。而在线的失火诊断则是电控柴油机故障诊断项目中的一个重要内容。为此采用曲轴的瞬时角加速度对发动机的失火故障进行监测,并制定了相应的诊断策略。实机试验表明,该失火诊断策略能实时有效地诊断出失火故障。