乙醇在涡流室式柴油机上试验的研究

利用超声波雾化系统,在一台涡流室式柴油机上进行了进气道供乙醇的试验研究。研究结果表明:超声波乙醇雾化系统,能够满足进气道供乙醇的性能要求,使柴油机燃用乙醇/柴油过程中,表现出稳定的工作性能;柴油机燃用乙醇/柴油的NOx、CO和碳烟排放比原机低,尤其满负荷时碳烟降幅较大;能量消耗率与原机基本相当,HC排放比原机高。     

双燃料发动机燃烧影响因素综述

近年来,双燃料发动机成为一个研究热点,由于一些含氧燃料不溶于或难溶于柴油,通常将其柴油共同应用在双燃料发动机中,双燃料燃烧模式作为一种替代传统柴油燃料燃烧的燃烧方式极具研究开发应用前景。本文主要以甲醇、乙醇和丁醇为例,通过对这三种含氧燃料的当前研究内容,分析对于双燃料发动机的影响因素,并为后续的研究提供理论依据。     

汽柴油双燃料发动机燃烧性能试验研究

基于一套经改造的汽柴油混合双燃料发动机系统,在柴油发动机进气道安装汽油喷射系统实现缸内均质的混合气制备,通过上止点直喷柴油控制燃烧相位,通过调整汽柴油比例及EGR比例研究双燃料发动机燃烧性能。研究显示:相比原机,汽柴油比例增大,排气温度降低,当汽柴油比例提高到65%时,呈现出低温燃烧效果,同时降低NOx和碳烟的排放,燃烧持续期缩短,最大压力升高率增大,但是整体燃烧效果更优;从EGR特性及其对缸内燃烧过程和发动机燃烧性能的影响来看,此款双燃料发动机在小负荷时宜采用热EGR,在大负荷时宜采用冷EGR;双燃料发动机进气温度提升对燃油消耗率和碳烟并没有明显影响,而对于NOx来说,进气温度会改善发动机燃烧性能提升缸内燃烧温度,进而NOx排放会出现恶化现象。     

柴油/酒精双燃料喷射控制试验的虚拟仪器技术应用

为进行燃用柴油／酒精双燃料电子控制喷射发动机的性能试验,确定掺烧乙醇时,发动机在整个转速和负荷范围内,柴油／酒精的混合比例对发动机综合性能的影响,找出最佳的柴油／酒精混合比例随转速、负荷的变化规律,利用虚拟仪器技术,设计了可对柴油／酒精混合比例进行编程控制且在现有发动机上易于改造的柴油／酒精双燃料喷射计算机控制试验系统。     

利用余热制氢的乙醇发动机模拟计算

本文研究了一种利用发动机余热制取氢气的装置,并将该装置应用在乙醇发动机上,通过chemkinpro软件中的激波管模型计算该装置生成的重整气加入发动机以后对发动机燃烧的影响,采用乙醇燃烧反应机理,研究了压力升高、温度升高、热量释放、各组分的含量变化等情况,比较了纯乙醇燃烧和乙醇混合重整气燃烧的特性,结果表明重整气中的氢气可有效促使点火延迟时间变短,有利于发动机性能改进。     

国内农用发动机研究现状与展望

本文综述了国内农用柴油机、汽油机、乙醇发动机、双燃料发动机、氢发动机、生物质斯特林发动机的研究现状,总结了这些农用发动机的优缺点,并指出洁净能源、短期可再生能源的利用是未来农用发动机燃料开发的主要方向;农用发动机燃料的经济性以及噪声的减少也是未来极有意义的研究方向。     

双燃料发动机天然气电子控制喷射系统的研究

受环境保护和能源短缺的牵掣,双燃料发动机改造技术在我国得到大力的发展,双燃料发动机电控喷射系统的研究是目前的一个热点。本文从硬件和软件两个方面详细论述了天灰气电控喷射系统的构成及基本原理,并进行了双燃料发动机台架实验,实验结果表明发动机的排放特性得到了改善,其可为工程实践提供参考。     

船用柴油/天然气双燃料发动机模式切换控制策略研究

船用柴油/天然气双燃料发动机在实际运行过程中,纯柴油模式与双燃料模式之间的切换极易造成发动机转速波动大、运行不稳定等情况,危害发动机的正常运行,此外,一些紧急情况(如天然气燃料不足、负荷突卸等)下,发动机需要快速平稳地完成不同模式的切换.针对这一需求,在控制系统硬件不变的前提下,根据双燃料发动机运行需求和机理,设计了基...     

国内外双燃料发动机发展现状

介绍了国内外主流厂家的柴油/天然气双燃料发动机,并从动力性、经济性、燃油替代率、NOX排放及甲烷逃逸量等方面对各机型进行比较。结果表明:国外双燃料发动机性能更加突出,热效率均在45%左右,NOX排放均满足IMO TierⅢ,且均实现微引燃。国内双燃料发动机多数还停留在混烧阶段,性能有待提高。结论:为提高双燃料发动机动力、经济及排放性能,建议采用进气歧管多点喷射和缸内直喷进气,开发"微引燃"双燃料发动机。     

柴油甲醇双燃料发动机动力性与经济性试验分析

介绍了柴油引燃甲醇双燃料燃烧对柴油机动力性和经济性的影响。在1台单缸、直喷、中冷柴油机上采用柴油引燃甲醇双燃料进行试验。结果显示甲醇柴油双燃料发动机在中高负荷及中高转速下运转可获得较好的燃油经济性。选择适当的引燃柴油量,双燃料发动机的动力性可以达到甚至超过原柴油的动力性。     

高压直喷天然气发动机技术简介

缸内高压直喷(HPDI)天然气发动机是一款缸内喷入少量柴油、引燃直喷入缸内的天然气的1A型双燃料发动机。HPDI发动机可以保持同排量柴油机原有的性能;与传统点燃式天然气发动机相比,主要优势表现为动力强劲,燃气消耗低,可靠性高,排温低,响应快;与进气道喷射双燃料发动机相比,替代率高,经济优势明显,市场前景光明。     

热洗车台上实现双燃料的工艺改进探讨

介绍了在热洗车台上卧式盘管加热炉实现双燃料的工艺改进方法，燃油供给系统的组成、原理以及如何进行正确的使用和保养。     

公共汽车液化石油气／柴油混燃系统

为达到现行国家汽车的排放标准,对在用柴油公共汽车的燃料系统进行了双燃料混燃的改装。讨论了机械式和电子式两种LPG／柴油混燃装置的构造和特点,并在改造前后对YC6108Q发动机进行了台架试验,测量出LPG／D的掺烧比和工作关系图,在控制中尽量按照该测量结果进行控制,改造后使用效果良好。     

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.     

Investigation of long-term engine oil performance using lab-based artificial ageing illustrated by the impact of ethanol as fuel component

The effect of ethanol and its combustion products on the lubrication system is not very well understood. In this paper, a novel lab-based artificial ageing method for the evaluation of engine oils for bio-fuelled automotives and the results thereof are presented. Artificial ageing of three fully formulated engine oils with addition of ethanol, acetaldehyde, and acetic acid was carried out. The oil formulations chosen represent a consequent series of optimisation steps based on the engine oil performance in terms of preservation of typical oil parameters, e.g. base reserve and oxidation, observed during the artificial ageing procedure. It was shown that ethanol as well as acetaldehyde has almost no effect on the oil degradation especially in the case that advanced additive technology was used. On the contrary, acetic acid significantly affected the formulated oil showing influence on the detergent chemistry and even caused sludge formation. The use of the novel artificial ageing method proved to clearly differentiate the impact of the respective compounds added with the possibility to simulate enhanced stress conditions without the need of time-consuming and expensive engine bench tests. Hence, the novel setup offers valuable input for the formulation and the pre-selection of future engine oils suitable for bio-fuel.     

矿用防爆柴油机结构改造

在防爆柴油机上通过对排气迟闭角的调整、进气栅栏的改造和供油系统供油量的调整,同时增加扫气泵就可使防爆改造后的柴油机在动力性和尾气排放性能上接近改造前柴油机的性能,而且减小机体受热对缸盖、活塞、活塞环和缸筒的损伤.     

针对脉冲发电机突变负载的微型燃气轮机工作性能研究

为分析有动力涡轮的微型燃气轮机在带动脉冲发电机中的性能,建立带动力涡轮的微型燃气轮机数学模型.因有动力涡轮的微型燃机是由动力涡轮驱动负载,其负载变化对燃机核心机影响不大,但为了使动力段转速恢复稳定而采用的改变供油量方法会对核心机产生很大影响.基于所建立的微型燃气轮机数学模型对其进行仿真计算,研究了该燃机设计点性能参数、...