内燃机的低温起动辅助措施

本文分析了内燃机各种低温起动辅助措施的特点及研究使用中的问题.从起动暖机过程和低温工况下内燃机磨损严重的角度出发,将起动辅助措施分为应急与升温起动两种,并提出了推荐使用的意见.     

低温对发动机起动的影响

叙述了发动机起动的必要条件,分析了低温对发动机起动的影响,并提出了改善低温起动性能的措施。     

柴油机常温与低温下的起动性能分析

对影响常、低温环境下柴油机起动的主要因素:起动阻力矩、压缩温度特性、起动转速、启动电机功率特性进行了论述,对常低温下的柴油机起动需求的差异进行了比较,通过实测发动机常低温起动时的发动机转速和启动电机电压,提出了柴油机常低温起动的启动电机特性要求。     

柴油机低温运转

目前内燃机在我国工业、农业、交通运输、国防工业等各条战线上得到了极为普遍的应用。由于我国地理位置及自然条件所致,冬季大部分地区平均气温在0℃以下。例如,一月份平均最低气温在-25℃以下的地区占我国陆地总面积的1/4,在0℃以下的地区占陆地总面积的4/5。而西北、东北、内蒙等边疆地区甚至到-35℃以下。根据上述情况,“内燃机的低温起动”在我国是一个迫切需要解决的问题。柴油机由于是靠压燃着火,问题更为严重,表现更为突出。我国寒区广大工农兵在实际工作中积累了不少内燃机低温起动方面的工作经验。发动机的生产厂及科学研究部门对     

CA6DN1-42柴油机低温起动试验研究

在不改变发动机静态提前角的情况下,采用人工冷冻室提供的低温环境,对CA6DN1-42柴油机在不同的低温环境下装用不同的起动电机、起动辅助装置时的起动性能进行试验研究,对试验结果进行分析,确定了该发动机的起动极限温度及相关配置要求。     

大功率水冷发动机低温预热起动系统的设计改进

为解决发动机的低温起动困难问题,依据液体加热器对发动机冷却系统循环加热的原理,设计了以液体加热器和发动机为核心的闭环系统,对原有安装方式进行分析和改进,通过试验验证,改进后的低温预热起动系统效果明显,使用效率高,安全可靠。     

一种单燃料纯甲醇发动机冷起动技术研究

文章针对目前甲醇汽车发动机生产厂家广泛采用的副油箱式辅助冷起动系统的缺陷,根据甲醇发动机的低温起动特性,研制了一种安装在进气总管的新型纯甲醇汽车发动机冷起动装置。该装置通过甲醇发动机进气预热冷起动技术,使得甲醇发动机低温起动时,甲醇燃料的蒸汽浓度能够达到着火点。试验结果表明,采用该冷起动技术后,甲醇发动机在环境温度为-10℃时可以实现冷起动,从而为单燃料纯甲醇发动机冷起动技术的应用与改进提供一定参考。     

柴油机的着火条件

原报告提出一个适用于发动机冷起动和高增压发动机在超量供油时燃烧效率等广泛问题的工作理论,此理论建立了十六烷值和压缩冲程内的温度时间积分间的关系。而本文摘译了有关冷起动部分,它可提供柴油机在设计时,预定其低温状况下的起动性能,及分析研究低温起动时的一些影响因素。     

拖拉机柴油机起动动力学的研究

为了使内燃机起动,其曲轴必须由外电源来驱动。起动时发动机的转动过程(起动动力学),以角速度值、旋转持续时间、阻力矩、消耗功率和起动耗费的功来表示。作为发动机主要附件之一的起动装置的尺寸与重量,就取决于这些数值的大小及其变化规律。     

车用PEMFC发动机水热管理与低温起动研究现状

质子交换膜燃料电池(proton exchange membrane fuel cell,PEMFC)发动机系统具有功率密度高、起动快和环境友好等优点,受到越来越多的关注。从PEMFC电堆和整体系统2个方面介绍PEMFC发动机系统的研究现状,分析水热管理方法及低温起动机理,针对PEMFC发动机系统的水热管理和低温起动问题进行综述。     

车用内燃机润滑系统的状态监测技术

综述了发动机润滑油状态监测技术的进展,包括：基于油液分析的发动机磨损状态离线／在线监测技术和润滑油质量离线／在线监测技术。认为发动机润滑油在线监测系统的研究将是该技术的发展方向。     

两种不同凸轮轴加工工艺的比较分析

凸轮轴是发动机上的一个重要零件,凸轮轴的质量优劣直接影响着发动机配气系统的正常运行,进而影响到发动机的性能及使用寿命。通过介绍两种不同的凸轮轴加工工艺过程,并详细说明传统加工工艺与一种新工艺的各自特点及运用领域,进行比较以期得出最优化的工艺过程。     

Reduction of emissions in a biodiesel‐fueled compression ignition engine using exhaust gas recirculation and selective catalytic reduction techniques

This paper analyzes the emissions of a single‐cylinder diesel engine fueled with biodiesel, using selective catalytic reduction (SCR) and exhaust gas recirculation (EGR) techniques. The aim of this paper is to compare both EGR and SCR techniques, which were studied under different brake powers. Grape seed biodiesel was used as a test fuel. Experiments were performed by both techniques at different loads and rates to find out the performance change in the engine and the change in the emission rates using both the techniques. Then the observations from both the techniques were compared, concluding that both the techniques show a sufficient reduction in NOx. Using the abovementioned techniques, a reduction in hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO₂), nitrogen oxides (NOx), and smoke was observed. The EGR technique is more suitable for low‐load engine vehicles, as it affects the efficiency of the engine with an increase in the fuel consumption, whereas the SCR technique is suitable for high‐load engines, which do not affect the efficiency of the engine with a decrease in the fuel consumption.     

降低直喷式柴油机NO_x排放的试验研究

未来柴油机要求更高的功率强度和更低的燃油消耗率．同时还必须满足更严格的排放法规。NOx排放是直喷式柴油机排放中最受关注的部分,且它的降低需要采用许多新技术。本文针对一台6缸涡轮增压直喷式柴油机的研制试验,介绍分析高压喷射系统、低涡流燃烧系统、涡轮增压器匹配优化等一些现有技术的效果和优劣,阐明了如何在简化结构、保持低成本的基础上改善缸内燃烧过程以降低NOx排放。     

电控柴油机优化标定研究现状和展望

采用电控技术后,柴油机的性能主要取决于控制参数的标定质量。分析了目前电控柴油机主要的优化标定技术和标定系统的现状,认为基于模型的优化标定技术和自动化标定系统是柴油机优化标定的发展趋势。     

火花点火发动机激光诱导荧光及散射测量技术应用研究

本文就汽车发动机的激光测量技术问题，重点介绍了散射光法及激光诱导荧光法在发动机研究开发过程中的应用及其机理。这些方法对电子控制稀燃火花点火发动机的设计和优化具有重要意义。     

提高柴油机滚轮使用性能的工艺方法研究

针对柴油机滚轮异常磨损和碎裂问题,结合滚轮工作中的受力情况,提出了可提高柴油机滚轮使用性能的加工工艺,如滚轮内孔精密珩磨加工、低应力加工、光整加工。经多型柴油机滚轮加工及柴油机运行试验验证,上述工艺方法切实可行,解决了滚轮异常磨损和碎裂问题。     

A comprehensive review on modeling and performance optimization of Stirling engine

Modeling with optimization has become a ubiquitous practice in the field of Stirling engine. A plethora of studies in the literature is dedicated in developing a feasible optimized model that can precisely predict the performance of Stirling engine. Hence, the purpose of this article is to compile and expansively review the thermodynamic models and optimization efforts made in pursuit of performance enhancement of the Stirling engine. An extensive range of models available in the literature is painstakingly discussed. Likewise, a wide variety of available optimization techniques spanning from conventional experimental and univariate methods to more complex multiobjective optimization approach are critically reviewed. A comparative analysis of the models is carried out based on the accuracy of their predictability of the performance of Stirling engines. Results obtained from the models are validated through the experimental data of the GPU-3 Stirling engine prototype. Several optimization techniques are investigated based on the effective and efficient optimization of operating and geometric parameters of the Stirling engine. The review concluded that the Comprehensive Polytropic Model of Stirling engine (CPMS) demonstrated better accuracy in comparison with other models. In addition, the multiobjective particle swarm optimization (MOPSO) technique was found to be effective and computationally efficient.     

柴油机清洁排放控制技术的发展及展望

以新一代燃烧技术的发展、演变及特征为出发点,从燃料改质技术、缸内净化技术和后处理技术3方面归纳了柴油机清洁排放控制技术研究的发展。重点分析了各种技术的特点以及对发动机排放的作用和影响,最后讨论了发动机清洁排放控制技术的未来发展趋势。     

Evaluation of water injection effect on compressor and engine performance and operability

Gas turbine performance enhancement technologies such as inlet fogging, combustor water/steam injection and overspray are being employed by users in recent years without fully evaluating their effect on gas turbine performance and operability. The water injection techniques can significantly affect the engine operating point thus a careful analysis should precede the application of performance enhancement devices, especially when the devices are retrofitted to old engines or engines operating at extreme conditions. The present paper examines the most widespread techniques that implement water injection by using in-house models that can reproduce the effects of water injection on the gas turbine and compressor off-design operation. The results are analyzed with respect to both performance augmentation and engine operability in order to give further insight on gas turbine operation with water injection. The behaviour of the gas turbine is interpreted while the risks on engine integrity due to water injection are identified.