4105增压柴油机排气系统模拟分析

排气系统是柴油机重要部件之一,对柴油机的性能、噪声等方面有很大的影响。为了更高效的优化排气系统,采用GT-POWER软件建立了柴油机排气系统模型,并对4105柴油机排气系统进行模拟分析。研究了排气支管长度、管径,排气总管管径,排气歧管管径变化对发动机性能的影响。通过选取不同数值来比较柴油机的扭矩、功率和充气效率。最终确定排气支管管径、长度以及排气总管管径等参数。为4105柴油机排气系统的设计提供理论参考。     

某型增压柴油机排气系统的仿真研究

排气系统设计是否合理对柴油机的性能有着重要影响,为了探求某型增压柴油机采用不同排气系统的优越性,本文以内燃机性能仿真软件GT-Power为平台,建立了工作过程仿真模型,利用试验数据验证了模型的可靠性。柴油机采用脉冲增压系统,针对定压增压系统和MPC增压系统对原机的排气系统进行了重新设计,建立了定压增压系统和MPC增压系统的柴油机模型,并分别对其进行了稳态工作过程计算,着重分析研究了采用不同排气系统对该柴油机性能的影响,为该柴油机排气系统的改进提供了参考依据。     

船用中速柴油机排气相位的优化研究

基于AVL-BOOST软件对6300型船用中速柴油机的排气相位进行了优化研究。应用建立的工作过程仿真模型,计算分析了排气正时对柴油机性能的影响,得到排气正时的最优值,为柴油机性能的进一步提高和优化设计指明了方向。     

基于流场分析技术对柴油机排气歧管结构的优化

针对煤矿井下防爆胶轮车所使用的柴油机排气歧管排气阻力较大的问题,应用SolidWorks建立柴油机排气歧管和烟气三维模型,使用GAMBIT软件划分网格,并使用流体性能分析软件Fluent对不同的进、排气管路进行烟气的速度流场模拟分析。根据分析结果对排气歧管进行优化,并对优化后的歧管、烟气建模,进行网格重新划分及速度流场模拟分析。分析结果表明:优化后的排气歧管涡流现象基本消失,排气阻力减小,流通性增强,切实改善了柴油机的排气性能。     

6300型柴油机增压系统的优化研究

应用AVL-BOOST软件对6300型柴油机的增压系统进行了优化研究。通过建立的工作过程仿真模型,计算分析了增压比和排气歧管直径对柴油机性能的影响,为柴油机增压系统的优化设计提供了依据。     

柴油机排气噪声特征提取方法及故障诊断研究

柴油机的排气噪声中含有很多能反映柴油机故障的有用信息,因此从排气噪声中提取有效的特征向量可用于柴油机故障诊断。通过对柴油机不同状态下的排气噪声分析,对比了基于功率谱分析、小波包分解和AR模型的排气噪声特征提取方法,发现基于AR模型的排气噪声特征提取方法能有效地区分柴油机失火及气阀机构故障。     

基于最小二乘支持向量机的柴油机声品质预测

为研究柴油机排气噪声并准确评价排气噪声声品质,对某型号柴油机排气噪声进行研究,采集5种不同转速下6级载荷的排气噪声样本,使用参考语义细分法主观评价噪声样本;利用最小二乘支持向量机和多元线性回归分别建立两个排气噪声品质客观评价模型,以心理声学参数(响度、锐度、粗糙度、抖晃度、A声压级等)为模型输入,利用模型输出和主观评价结果对比。结果表明:最小二乘支持向量机可以用来作为声品质的预测模型,更接近主观评价结果,误差可以稳定控制在10%以内。     

某型柴油机热力学计算分析

本文利用AVL-boost软件建立某型柴油机的热力学模型,对比柴油机脉冲转换排气方案、MPC排气方案两种排气系统的整机性能参数,优化出一种方案,在此方案基础上,进行不同涡流比情况下的推进特性计算,得出一系列性能参数,为气道的优化设计提供指导。     

防爆柴油机排气冷却系统工况仿真分析

以柴油机为动力源的工程车辆被广泛应用在石油、化工、军工、油漆等行业中,其作业过程往往会产生易燃、易爆物质,从而形成爆炸性危险环境,导致火灾、爆炸等安全事故的发生,为了保障安全生产,有必要对具有防爆特性的柴油机做深入研究。应用防爆叉车测试工况下的热平衡温度数据,对防爆柴油机及排气冷却系统的运行工况进行建模和仿真计算,并着重分析了防爆叉车测试工况系统下防爆柴油机排气冷却系统存在的问题,最后根据排气冷却系统试验研究数据分析和仿真结果,为防爆柴油机排气冷却系统的优化设计提供了方向及理论支持。     

柴油机SCR后处理系统的数值模拟研究

为了提高柴油机排气后处理系统的工作性能,本文利用CFD软件对某型号柴油机排气后处理系统进行了数值模拟。通过分析SCR入口NH3浓度均匀性、速度均匀性和混合器前后压降等重要参数,为柴油机排气后处理系统的设计提供优化方向。结果表明,SCR入口NH3浓度均匀性、速度均匀性均大于0.92;混合器前后的压降主要由环形挡板导致。     

LJ376QC型微型车用高速柴油机的研制

LJ376QC型高速柴油机是在吸收国外CL50、CL70型车用柴油机技术基础上，结合我国市场特点而自行研制的新机型，简要介绍该机的技术参数、设计方案、结构特点和整机性能。     

车用柴油机高原性能模拟试验及性能提升策略

通过柴油机高原性能模拟试验,分析了柴油机的动力性、经济性随海拔高度的变化规律,以及高原环境对柴油机起动性能和热平衡性能的影响,提出了高原增压、供油系统调整及优化、低气压低温起动、热平衡控制、电控柴油机高原标定等提升车用柴油机高原性能的技术对策,为研究进一步提高柴油机的高原环境适应性提供了参考。     

Design approach for single piston hydraulic free piston diesel engines

The operating characteristics of a single piston hydraulic free piston diesel engine differ significantly from conventional diesel engines and this provides a theoretical basis for controlling and optimizing the design of the engine. The design of the proposed engine intended as a power supply for a hydraulic propulsion vehicle is presented. An engine performance forecast model was generated in AMESim. The performance of the prototype engine is predicted and the predictive results are verified with experiments. The particular features of the engine are discussed. The dynamic characteristics of the prototype engine are analyzed and the results indicate the rationality and feasibility of the engine design parameters. The features of the controllable working frequency and the intermittence output flows are provided. The flow capacity characteristics of the hydraulic valves on the prototype engine are offered. The methods for starting and the operation after misfire are presented.     

Design approach for single piston hydraulic free piston diesel engines

The operating characteristics of a single piston hydraulic free piston diesel engine differ significantly from conventional diesel engines and this provides a theoretical basis for controlling and optimizing the design of the engine. The design of the proposed engine intended as a power supply for a hydraulic propulsion vehicle is presented. An engine performance forecast model was generated in AMESim. The performance of the prototype engine is predicted and the predictive results are verified with experiments. The particular features of the engine are discussed. The dynamic characteristics of the prototype engine are analyzed and the results indicate the rationality and feasibility of the engine design parameters. The features of the controllable working frequency and the intermittence output flows are provided. The flow capacity characteristics of the hydraulic valves on the prototype engine are offered. The methods for starting and the operation after misfire are presented.     

4105G型柴油机设计

本文对照 41 0 5Q型柴油机研究分析和确定了 41 0 5G型柴油机的性能指标 ,并进行了调试 ,使其性能和油耗等各项指标完全符合要求。还对冷却系统、进排气系统、油底壳、集滤器等相关零件进行了设计 ,保证了柴油机的配套使用要求     

An investigation on the performance of a Brayton cycle waste heat recovery system for turbocharged diesel engines

A Brayton cycle waste heat recovery (WHR) system for turbocharged diesel engines was proposed and the performance of a diesel engine integrated with the proposed system was investigated. The waste heat recovery system is integrated with the turbocharging system of diesel engines, using the turbocharger compressor as the Brayton cycle compressor. The engine cycle simulation code GT-Suite 7.0 was used to investigate the performance of a diesel engine integrated with the WHR system. A Brayton cycle turbine was designed and its performance was simulated with a through-flow model. The turbocharging system of the original engine was modified and the energy flow distribution between the diesel cycle and the Brayton cycle was optimized. Results show that the fuel economy of the diesel engine can be improved by 2.6% at high engine speed and 4.6% at low engine speed under engine full load operating conditions when equipped with the Brayton cycle WHR system. The influence of turbocharger parameters on the WHR engine performance was invesgated.     

基于虚拟仪器的柴油机示功图采集系统设计

柴油机示功图包含了柴油机热力转换过程和工作状态的相关信息,通过计算,可以得到各缸平均指示压力、指示功和最高爆压等柴油机的重要性能指标。虚拟仪器具有效率高、性能好、控制灵活、精度高等特点。为此以虚拟仪器系统为开发平台,把传统仪器的所有功能模块集成在一台计算机中,设计了基于虚拟仪器的柴油机示功图采集系统,为柴油机性能监测与故障诊断提供了有效的技术手段。     

车用柴油机噪声品质预测模型的建立

车用柴油机辐射噪声已成为环境污染噪声的重要组成部分,开展车用柴油机噪声品质的预测与评估研究具有重要的理论与实际意义。以Q型车用柴油机为例,研究其在变负荷及转速工况下表面辐射噪声品质情况,为进一步提高整机声品质,开展柴油机结构声学设计奠定了理论基础。研究国内外车用柴油机客观评价特征,选取物理声学特征峭度、冲击量特性以及心理声学特征响度、尖锐度、粗糙度和波动强度参量来描述辐射噪声的客观特征;针对柴油机噪声特点,采用分类对偶比较法开展以专业听审人群为目标的综合满意度评价研究;应用多层感知器神经网络算法建立起该车用柴油机声品质预测模型。研究表明,车用柴油机噪声品质预测模型能够准确地反映客观评价参量与主观满意度之间的非线性映射关系。     

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.