高原环境对船用柴油机的影响及性能改善研究

针对高原低压、高寒的恶劣环境导致高原船艇用柴油机低温起动性差、冷却效果不良以及功率下降等一系列现实问题,通过分析高原环境对船用柴油机性能的影响,结合某型高原船用D683B型柴油机的结构特点和在班公湖地区的使用管理现状,从起动性能、冷却性能和动力性能方面提出船用柴油机在高原环境下性能提升的对策措施,为高原船艇柴油机的使用管理提供借鉴。     

低气压低温环境对柴油机起动性能的影响及改进措施

分析了高原低气压低温环境对柴油机起动性能的影响,通过现有冷起动辅助措施的对比分析,提出了改善柴油机低气压低温起动性能的技术措施。     

高海拔环境下柴油机性能影响及优化

通过工程实践和查阅相关文献,充分讨论高海拔对柴油机运行影响,通过标定可以改善柴油机高原性能情形。高海拔环境,外界冷却能力下降,柴油机进气流量降低,燃烧恶化,导致柴油机动力性、经济性和可靠性下降。通过减少外特性油量、优化喷油规律及其他控制器等措施,可最大限度提高柴油机高原性能。     

宣工两款高原推土机通过质量检测认证

最近，机械工业高原工程机械产品质量监督检测中心对宣工生产的TYG165、TG140-1型高原履带推土机进行了海拔200 m的实地整机性能试验，试验表明各项性能指标（动力性、经济性、热平衡性能、排放性能、起动性能）均符合标准要求，达到设计指标，能满足海拔4000 m至5000 m高原地区使用要求。2002年8月6日该中心颁发了“高原工程机械产品质量检测认证书”。TYG165、TG140-1型高原履带推土机试制试验成功为该公司增添了适应高原气候环境的新产品，具有较大的市场空间。宣工两款高原推土机通过质量检测认证@赵况…     

发动机高原性能研究现状与展望

介绍了发动机高原性能的试验与仿真研究现状,提出发动机高原热平衡研究与新型涡轮增压技术的开发将是今后发动机高原性能研究的重点方向。     

高原环境下大功率柴油机燃烧性能分析及功率恢复研究

中国的高原面积非常广阔,这就使得高原地区运行着大量的动力设备。高原地区的大气压力相对较,环境温度的变化非常大,环境条件较为恶劣,直接影响柴油机的运行性能。为了能够改善大功率柴油机的高原性能,发挥大功率柴油机原机型燃烧系统基础作用,针对燃烧室的廓形、燃烧室的喉口半径、燃烧室的涡流比等相关参数开展优化研究,最终明确平原环境下优化功率,高原环境下在一定程度上恢复燃烧系统的功率参数。     

车用柴油机起动性能研究

随着国家对车用柴油机排放法规的制定和强制执行，各柴油机厂为降低排放作了大量工作，开发出了许多低排放机型。但是，我们发现有些低排放车用柴油机在低温环境下起动困难，而且起动后排气冒浓烟，严重污染环境。为解决这一问题需要分析柴油机的起动过程并进行试验研究。     

高海拔柴油机燃烧过程研究综述

通过对柴油机高海拔燃烧过程的研究,可以探索高原环境对柴油机性能影响的机理,为柴油机高原性能提升提供理论依据。本文综述了国内外柴油机高海拔燃烧过程研究的总体情况,总结了高海拔环境对柴油机燃烧过程的影响规律,分析了提升柴油机高海拔燃烧特性的先进技术及策略。     

霍尔传感器在柴油机低温起动中的应用

基于霍尔传感器工作原理,设计了柴油机低温起动系统的霍尔型起动电压、电流、转速传感器及其信号处理电路;利用新型的柴油机低温起动试验方案,进行了低温起动电压、起动电流、起动转速的性能试验,结果表明：最大低温起动电流达到680 A,起动电压大于8.6 V,起动平均转速为280 rad/min,性能完全满足柴油机低温起动系统要求。同时也验证了霍尔传感器能够准确测试柴油机低温起动系统的起动电压、电流和转速信号。     

高海拔柴油发动机性能改进研究现状与发展趋势

本文总结了我国高原地区环境特点、海拔高度等环境因素对柴油发动机性能的影响,综述了国内外高原条件下柴油发动机起动性能改进、燃烧性能改进和排放特性改进三个方向的研究现状,分析了柴油发动机性能改进的发展方向。最后,针对柴油发动机高海拔工况下的性能需求,提出柴油发动机多参数协同优化研究是柴油发动机性能改进的重要发展方向。     

Specific engine performance and gaseous emissions characteristics of European test cycle and worldwide harmonized driving cycle for a heavy-duty diesel engine

This study compares the engine operating behavior and regulated gaseous emissions characteristics between the reference European cycles (ESC/ETC) and the worldwide harmonized driving cycles (WHSC/WHTC), which will be applied in the Euro VI heavy-duty diesel engine emissions regulations, for the diesel particulate filter (DPF) equipped Mercedes 12 L diesel engine. The speed and load distribution for two additional representative harmonized cycles which cover a more realistic operating range for a heavy duty engine were established to verify the engine performance over wide range of the cycle work, fuel consumption, and exhaust system temperature as well as engine coolant temperature for repeated validation tests. The WHTC, including an additional test with cold start and transient operation before the hot start, had a substantial influence on the THC, CO, NOx, and PM exhaust emissions levels because of the engine heat-up time and temperature rising characteristics of aftertreatment device. Moreover, the different engine operating conditions of the WHSC influenced on the specific engine performance and gaseous emissions behavior unlike those of the ESC. Finally, the statistical analysis results through repeated tests validated the stationary and transient cycles running at the fully warm-up condition, however, those of WHTC were closely dependent on the inclusion of cold start condition or aggressive acceleration gradient of engine speed and load trace.     

柴油醇的燃料性质和排放特性

为解决柴油醇在应用中存在的相分离、十六烷值低下等问题,提出一种由中碳醇 低分子醚 高分子聚合物 有机硝酸酯构成的复合添加剂.结果表明:添加1%～2%容积百分比的复合添加剂后,柴油醇的溶解度明显提高;并且发动机的冷启动试验也表明加入复合添加剂后,柴油醇的着火性能己同于柴油的水平.由发动机台架试验还研究了柴油和不同乙醇掺合率的柴油醇给与发动机的燃料经济性、排气烟度和THC、CO、NOx气体排放的影响.结果表明:柴油醇以重量计的比油耗较柴油的相应地增加,但以能量计的有效热效率却较柴油的略有提高;各种乙醇掺合率下的排气烟度都大幅地降低;NOx排放浓度则随负荷增加而逐渐增大,但在高负荷工况时,随乙醇掺合率的增加,NOx排放浓度呈下降趋势.     

Method for evaluating the reliability of compressor impeller of turbocharger for vehicle application in plateau area

As turbocharging diesel engines for vehicle application are applied in plateau area, the environmental adaptability of engines has drawn more attention. For the environmental adaptability problem of turbocharging diesel engines for vehicle application, the present studies almost focus on the optimization of performance match between turbocharger and engine, and the reliability problem of turbocharger is almost ignored. The reliability problem of compressor impeller of turbocharger for vehicle application when diesel engines operate in plateau area is studied. Firstly, the rule that the rotational speed of turbocharger changes with the altitude height is presented, and the potential failure modes of compressor impeller are analyzed. Then, the failure behavior models of compressor impeller are built, and the reliability models of compressor impeller operating in plateau area are developed. Finally, the rule that the reliability of compressor impeller changes with the altitude height is studied, the measurements for improving the reliability of the compressor impellers of turbocharger operating in plateau area are given. The results indicate that when the operating speed of diesel engine is certain, the rotational speed of turbocharger increases with the increase of altitude height, and the failure risk of compressor impeller with the failure modes of hub fatigue and blade resonance increases. The reliability of compressor impeller decreases with the increase of altitude height, and it also decreases as the increase of number of the mission profile cycle of engine. The method proposed can not only be used to evaluating the reliability of compressor impeller when diesel engines operate in plateau area but also be applied to direct the structural optimization of compressor impeller.     

铝合金冷硬树脂砂在大功率柴油机铸件中的应用研究

柴油机是以柴油或劣质燃料油为燃料,压缩发火的往复式内燃机,在船用发动机中,柴油机已经取得了绝对统治地位,因此柴油机铸件质量的好坏决定了柴油机的使用寿命长短,应用铸造铝合金冷硬树脂砂铸造工艺,能较大幅度地提高柴油机铸件的质量,从而提高柴油机的使用寿命。     

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.     

D150A柴油机气门正时的模拟计算

在一台单缸150柴油机性能方案计算优化的过程中,应用性能分析软件AVLBOOST建立了柴油机模型,在模型校准的基础上,针对该机排气门开启角较大这一状况,以满足功率、燃油消耗率等指标要求为目标,以气缸最高燃烧压力、排气温度为约束条件,对排气正时等进行了改进,为进一步提高柴油机的性能奠定了基础。     

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.     

基于MCS-51单片机的柴油机电控调速系统

开发了一种基于MCS-51单片机的柴油机电控调速系统,以满足高燃油经济性、低排放性、好的动力性等多目标设计要求。详细介绍了控制系统的工作原理和控制软件设计。该电控调速系统可以克服原机械式调速系统的一些缺陷,如燃烧不充分和故障率高等。     

Performance and emission studies on an agriculture engine on neat Jatropha oil

Diesel engines have proven their utility in the transportation, agriculture, and power sectors in India. They are also potential sources of decentralized energy generation for rural electrification. Concerns on the long-term availability of petroleum diesel and the stringent environmental norms have mandated the search for a renewable alternative to diesel fuel to address these problems. Vegetable oils have been considered good alternatives to diesel in the past couple of years. However, there are many issues related to the use of vegetable oils in diesel engine. Jatropha curcas has been promoted in India as a sustainable substitute to diesel fuel. This study aims to develop a dual fuel engine test rig for evaluating the potential suitability of Jatropha oil as diesel fuel and for determining the performance and emission characteristics of an engine with Jatropha oil. The experimental results suggest that engine performance using Jatropha oil is slightly inferior to that of diesel fuel. The thermal efficiency of the engine was lower, while the brake-specific fuel consumption was higher with Jatropha oil compared with diesel fuel. The levels of nitrogen oxides (NOx) from Jatropha oil during the entire duration of the experiment were lower than those of diesel fuel. The reduction of NOx was found to be an important characteristic of Jatropha oil as NOx emission is the most harmful gaseous emission from engines; as such, its reduction is always the goal of engine researchers and makers. During the entire experiment, carbon monoxide (CO), hydrocarbon (HC), and carbon dioxide (CO₂) emissions in the case of using Jatropha oil were higher than when diesel fuel was used. The higher density and viscosity of Jatropha oil causes lower thermal efficiency and higher brakespecific fuel consumption. The performance and emission characteristics found in this study are significant for the study of replacing diesel fuel from fossils with Jatropha oil in rural India, where the availability of diesel has always been a problem.     

Multi-stage turbocharger system analysis method for high altitude UAV engine

A multi-stage turbocharger system analysis method has been presented for a hydrogen fueled internal combustion engine targeted for High altitude long endurance UAV (HALE UAV), of which cruising altitude is 60000 ft. To utilize an internal combustion engine as a propulsion system of a HALE UAV, proper inlet pressure boost system such as a series of turbochargers should be ready, which makes engine performance less sensitive to flight altitude. In this study, to boost rarefied intake air pressure up to 1.7 bar to avoid early ignition of hydrogen and to produce required power from engine, we used a boost system which consists of three-staged turbocharger accompanied by intercooler to reduce compressed air temperature. To analyze multi-stage turbocharger performance at the cruising altitude, we established an explicit one-dimensional analysis method by matching required power between compressors and turbines. Then adequate turbochargers were searched for from commercially available models based on performance analysis results. One-dimensional analysis was also applied from sea level to the cruising altitude to decide turbocharger operating lines were located within each turbocharger operating ranges.