柴油机机油耗的模拟分析

在应用ANSYS软件计算得到活塞和缸套变形的基础上,应用GLIDE软件对不同活塞、活塞环和缸套组合的机油耗进行了计算与分析,计算结果表明:选择合适的活塞环可以有效地降低整个转速区域内的机油耗,加强活塞的冷却和采用椭圆形缸套均可降低发动机高速时的机油耗.     

浅谈活塞环对发动机机油耗的影响

通过对发动机油耗影响因素的分析,说明活塞环在控制机油耗方面起到至关重要的作用。     

国Ⅳ重型柴油机降机油耗技术探讨

随着我国对排放要求不断提高,部分大城市开始实施国Ⅳ排放：如北京,上海等。针对我国实际情况采用SCR技术达国4排放要求是我国众多发动机厂采用的主流技术。但由于国4排放中对颗粒的要求只有国3颗粒的1/5：机油消耗中约有1/10转换为颗粒排放出来。那么如何降低机油耗成为能否采用该技术的关键。本文就是介绍如何对活塞、活塞环、气缸套及气缸体等相关零部件进行设计改进达到国4重型柴油机机油耗要求的。     

影响单缸柴油机机油耗的因素及分析

以单缸蒸发冷却式柴油机为例,分析柴油机机油耗测试过程存在的各种影响因素及减少测试误差的措施。     

某V型发电柴油机机油耗高问题分析及改进

针对某V型发电柴油机机油耗过高的情况,采用仿真及试验的手段,确定了机油消耗量大的主要原因,明确了降低活塞温度、优化活塞环组运动、增强控油能力的优化方向。通过优化改进气缸套网纹、活塞内冷油道结构和活塞环组尺寸,优化活塞、活塞环和缸套的配合间隙,增加刮碳环,实现了对活塞环组降温、顺气、控油和及时清除积碳的效果,达到降低柴油机机油耗的目的,改进方案经市场验证效果良好。     

柴油机机油耗高的排查改进及控制

介绍了柴油机机油消耗高的排查方法,通过对机油消耗率影响因素的分析,进行试验和测量,提出了设计改进措施和质量控制措施,使柴油机机油消耗率得到了进一步降低,同时也促进了柴油机的环保排放达标。     

发动机下排气量大、机油耗高和断环问题的分析及改进

本文主要对某柴油机出现下排气量大、机油耗高及断环等问题的分析,通过对活塞环、活塞及缸套摩擦副的改进设计及试验验证,提出了＂下排气量大＂、＂机油耗高＂、＂断环＂、＂拉缸＂等问题的改进方案.     

CA6DE3柴油机低机油耗开发

CA6DE3国Ⅲ排放电控柴油机的低机油耗开发是通过对活塞环、活塞与缸套的间隙和活塞第一道环槽的优化来实现的。试验结果表明,样机优化后的标定功率机油燃油耗比为0.07%,满足低机油耗开发工程目标0.2%的要求。     

柴油机机油外来污染物——烟炱的分析

柴油机机油外来污染物之一是柴油燃烧过程形成的烟炱,过多的烟炱含量不仅缩短柴油机机油的寿命,而且增加零部件的磨损.本文重点对使用过程中的旧油进行红外光谱测试,分析烟炱对粘度增长的影响.     

YHY-1型内燃机车柴油机油耗仪

YH-1型油耗仪采用89C52单片机对流量及温度传感器输出信号进行处理,大大简化了油耗仪的硬件结构,提高了精度及可靠性.油耗仪测量精度能满足机务段机车检修工作的需要,同时具有结构简单、使用方便、造价低、测量时间短等特点.     

铁路内燃机车柴油机油烟炱含量的测量

介绍了近年来柴油机的发展及评定项目、几种烟炱的测定方法以及铁路柴油机油烟炱含量的测试。     

运用中柴油机油的分析及化验意义

分析了柴油机油在使用过程中的污染变质问题,说明运用中柴油机油化验分析的意义,并提出实际应用中存在的问题及建议。     

Performance of rapeseed oil blends in a diesel engine

The concept that 100% vegetable oil cannot be used safely in a direct-injection diesel engine for long periods of time has been stressed by many researchers. Short-term engine tests indicate good potential for vegetable oil fuels. Long-term endurance tests may show serious problems in injector coking, ring sticking, gum formation, and thickening of lubricating oil. These problems are related to the high viscosity and nonvolatility of vegetable oils, which cause inadequate fuel atomization and incomplete combustion. Fuel blending is one method of reducing viscosity. This paper presents the results of an engine test on three fuel blends. Test runs were also made on neat rapeseed oil and diesel fuel as bases for comparison. There were no significant problems with engine operation using these alternative fuels. The test results showed increases in brake thermal efficiency as the amount of rapeseed oil in the blends increases. Reduction of power-output was also noted with increased amount of rapeseed oil in the blends. Test results include data on performance and gaseous emissions. Crankcase oil analyses showed a reduction in viscosity. Friction power was noted to increase as the amount of diesel fuel in the blend increases.     

Study on cottonseed oil as a partial substitute for diesel oil in fuel for single-cylinder diesel engine

The experiments were undertaken to obtain the knowledge necessary for raising the thermal efficiency of mixed oil composed of cottonseed oil and conventional diesel oil and for improving the performance of engine fuelled by the mixture. The experimental results obtained showed that a mixing ratio of 30% cottonseed oil and 70% diesel oil was practically optimal in ensuring relatively high thermal efficiency of engine, as well as homogeneity and stability of the oil mixture. A quadratic regressive orthogonal design test method was adopted in the experiment designed to examine the relationship between specific fuel consumption and four adjustable working parameters (intake-valve-closing angle (α), exhaust-valve-opening angle (β), fuel-delivery angle (θ) and injection pressure (P, in 10⁴ Pa)) when the above-mentioned oil mixture was used. The mathematical equations characterizing the relationship were formulated. The equation of specific fuel consumption derived from the regressive test under each operating condition was set as the objective function and the ranges for the four adjustable working parameters were the given constraint condition. Models of non-linear programming were then constructed. Computer-aided optimization of the working parameters for 30:70 cottonseed oil/diesel oil mixed fuel was achieved. It was concluded that the predominant factor affecting the specific fuel consumption was fuel-delivery angle θ, the approximate optimal value of which, in this specific case, was 3–5° in advance of that for engine fuelled by pure diesel oil. The experimental results also provided useful reference material for selection of the most preferable combination of working parameters.     

DF8B型机车柴油机费水原因的判断与维修

1 概述 DF8B型机车柴油机冷却系统由高温、低温两个部分组成。高温水系统用于冷却气缸套、气缸盖和增压器;低温水系统用于冷却增压器压气机出来的增压空气。如果冷却水系统发生故障（如循环不畅、漏水、烧水等）,将导致柴油机主要部件（如气缸盖、活塞、气缸套、气门、喷油器等）过热,使其机械性能下降,产生严重热应力,导致变形和裂纹,高温也将引起机油物理化学性能变坏和结焦,使其失去润滑性能,最后导致拉缸、零件咬死、断裂等,高温还会引起空气充量下降而使燃烧不充分,影响柴油机的性能。因此,良好的冷却系统是柴油机正常工作的必要条件。     

16V240ZJD型柴油机机油系统分析及改进建议

对16V240ZJD型柴油机机油系统在机油滤清、机油离心精滤器、主机油泵出口旁通管路末端的减压阀结构、油压测点位置、油压继电器接点位置等方面进行分析,并提出改进建议.     

ND5型机车柴油机油、水温度超高故障的原因分析及防止措施

简述了ND5型机车柴油机油、水温度超高故障的类型与危害,分析了故障产生的原因,并以机车实际运用为依据,结合多年的经验,针对性地提出解决该故障的主要措施。     

MIXPC增压系统在大功率机车柴油机上的应用

为了优化性能,在大功率机车柴油机上应用MIXPC涡轮增压系统。使用上海交通大学开发的一维非定常流FVM-TVD法性能模拟计算程序,对MIXPC系统排气管系统结构参数和配气正时进行了优选。经性能及耐久试验说明,采用MIXPC系统是成功的,可使柴油机油耗率低、排温低、低工况性能好,各缸排温均匀。