共查询到19条相似文献,搜索用时 78 毫秒
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为某轻型柴油机开发蝶阀排气制动辅助系统,通过仿真计算得到不同排气背压下的发动机制动功率,根据整车参数对整车需求制动功率进行仿真计算,综合考虑各种配套车型发动机制动功率需求,确定所需排气背压.通过发动机台架试验及整车性能试验验证,确认辅助制动性能满足制动系统技术标准要求;进行500 h耐久试验,验证了整车制动可靠性,结果... 相似文献
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为分析排气管内压力波动对发动机二冲程制动功率的影响,以某重型柴油机为研究对象,利用GT-Power建立发动机二冲程制动一维模型,通过修改排气型线开展排气道压力波动对制动性能影响的研究。结果表明:第二次减压制动(the second compression release braking, 2nd CRB)相位开启时的压力波动会影响到其他气缸的排气回流,进而影响发动机的制动功率。进一步对排气管进行三维流场计算,证明了其他气缸2nd CRB相位排气门开启时的压力波传递对排气回流阶段排气回流的影响。最后通过试验设计(design of experiment, DoE),结合响应面拟合和粒子群算法对排气管几何尺寸进行优化,优化后该柴油机二冲程减压制动模式下2 100 r/min工况的最大制动功率可达到395.08 kW。 相似文献
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李曼 《柴油机设计与制造》2016,(4):28-31
D系列电控柴油机机原缸内线束及支架,线束布置欠合理,尤其是带缸内排气制动功能时,因缸内空间狭小,与排气制动蝶阀的固定螺栓距离太近,易导致线路短路。采用改进线束走向的方法,并考虑适当的整体式固定支架,达到尽可能提高此产品的可靠性及稳定性。 相似文献
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就匹配压缩释放辅助系统的某六缸柴油机,对运动机构的核心部件排气凸轮进行优化改进.在外基圆不变的情况下,通过在内基圆上对凸轮进行"加法",降低可靠性风险.同时,采用AVL-BOOST、AVL-EXCITE TD、Hypermesh以及MATLAB,研究了不同转速下排气凸轮(压缩-释放段)第1次开启的角度及爆发压力对制动功... 相似文献
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试验温度场与柴油机排气歧管工作的温度场尽可能一致,则可快速验证柴油机排气歧管的改进效果。为了快速验证柴油机排气歧管的优化改进效果,设计开发了一款模拟柴油机排气歧管工作温度场的试验装备。装备采用电磁场分布加热方法,以及通过高温风冷和低温雾冷方式实现柴油机排气歧管实际工况的模拟,这有助于缩短柴油机排气歧管开发周期,降低其开发成本。结果表明:通过改变电源的功率,可以控制加热线圈的加热速率;通过调整加热线圈的磁力线密度,可以改变加热线圈的加热效率,以有效调控柴油机排气歧管的温度场。 相似文献
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柴油机产生的高温废气是船舶红外信号的主要来源,红外成像系统可根据红外信号对船舶进行定位。选用气液两相流喷嘴,对柴油机排气喷雾冷却过程中的热负荷和所需水量进行了理论计算,以WD-615斯太尔柴油机试验平台为基础,将计算结果与实验数据进行对比分析,验证了柴油机排气系统喷雾冷却降温技术对柴油机排气的红外抑制效果。结果表明,该方法可有效降低柴油机排气温度,随着喷入水流量的增加,柴油机排气温度逐渐下降,下降速度由快及慢,当水量增加到一定程度时,用水量对排气温度再无影响。 相似文献
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柴油机排气后处理技术及发展方向 总被引:8,自引:1,他引:8
本文介绍了柴油机排气后处理技术的现状和发展方向,针对柴油机中NOx和碳烟微粒处理间的固有矛盾,概述目前柴油机排气控制技术所采取的一系列措施,探讨了等离子体技术是未来柴油机排气后处理的发展趋势。 相似文献
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引进大功率交流传动内燃机车的选型 总被引:3,自引:1,他引:2
详细介绍了引进大功率交流传动内燃机车的选型过程,包括机车功率及辅助功率的确定、柴油机的选型、主传动和辅助传动方式的选择以及制动系统的选型;同时,研究和阐述了交流电传动矢量控制、微机网络控制及黏着控制的理论和观点。 相似文献
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Hydrogen (H2) is being considered as a primary automotive fuel and as a replacement for conventional fuels. Some of the desirable properties, like high flame velocity, high calorific value motivate us to use hydrogen fuel as a dual fuel mode in diesel engine. In this experiment, hydrogen was inducted in the inlet manifold with intake air. The experiments were conducted on a four stroke, single cylinder, water cooled, direct injection (DI), diesel engine at a speed of 1500 r/min. Hydrogen was stored in a high pressure cylinder and supplied to the inlet manifold through a water-and-air-based flame arrestor. A pressure regulator was used to reduce the cylinder pressure from 140 bar to 2 bar. The hydrogen was inducted with a volume flow rate of 4l pm, 6l pm and 8l pm, respectively by a digital volume flow meter. The engine performance, emission and combustion parameters were analyzed at various flow rates of hydrogen and compared with diesel fuel operation. The brake thermal efficiency (BTE) was increased and brake specific fuel consumption (BSFC) decreased for the hydrogen flow rate of 8l pm as compared to the diesel and lower volume flow rates of hydrogen. The hydrocarbon (HC) and carbon monoxide (CO) were decreased and the oxides of nitrogen (NOx) increased for higher volume flow rates of hydrogen compared to diesel and lower volume flow rates of hydrogen. The heat release rate and cylinder pressure was increased for higher volume flow rates of hydrogen compared to diesel and lower volume flow rates of hydrogen. 相似文献
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针对我国铁路内燃、电力机车上使用的JZ-7型空气制动机中作用阀的作用与故障现象,进行了故障原因分析,并对防止作用阀发生故障提出了建议。 相似文献
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In the present experiment, a computerized single cylinder diesel engine with a data acquisition system was used to study the effects of oxygen enriched combustion technology (OECT) on the performance characteristics. The use of different levels of oxygen-enriched air was compared with respect to percentage load. Increasing the oxygen content in the air leads to faster burn rates and increases the combustibility at the same stoichiometry (oxygen-to-fuel ratio). These effects have the potential to increase the thermal efficiency and specific power output of a diesel engine. The power increases considerably with oxygen enrichment. In addition, oxygen enrichment can also be considered as a way to reduce the sudden loss in power output when the engine operates in a high load condition. Assessed high combustion temperature from the oxygen enriched combustion leads to high combustion efficiency. OECT reduces the volume of flue gases and reduces the effects of greenhouse effects. Engine tests were conducted in the above said engine for different loads and the following performance characteristics like brake power (BP), specific fuel consumption (SFC), mean effective pressure, brake thermal efficiency, mechanical efficiency, and exhaust gas temperature were studied. The objective of this paper is to address, in a systematic way, the key technical issues associated with applying OECT to single cylinder diesel engines. 相似文献
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建立了BFM1015柴油机气缸盖进气道和冷却水腔的改进设计模型,对进气道的流通特性进行了试验对比和冷却水腔的流场分析对比,完成了气缸盖改进模型的砂芯快速成型和铸造加工。在单缸柴油机试验台上对改进设计的新气缸盖进行了试验研究并和原气缸盖的试验结果进行了对比分析。结果表明:安装新气缸盖的单缸柴油机在高转速时燃油消耗率比安装原气缸盖时明显降低,降幅最高达到7g/(kW.h);在相同负荷下,新气缸盖火力面的温度比原气缸盖显著下降,在排气门鼻梁区温度下降最明显,最高下降61.8K;新气缸盖的传热能力比原气缸盖提高约50%。 相似文献
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通过一台6缸直喷、高压共轨柴油机改装成的柴油引燃天然气发动机.试验研究预喷正时和预喷油量对燃烧参数和性能参数的影响,结果表明:相对单次喷射,较晚的预喷正时(30°CA BTDC)能提高发动机有效热效率(BTE),降低HC、CO排放,但NOx排放恶化,而较早的预喷正时(60°CA BTDC)能够在提高发动机BTE的同时,降低HC、CO排放,并且NOx排放基本保持不变;当预喷正时为60°CA BTDC,预喷油量适当增多(3~5 mg/cyc)能进一步提高发动机BTE,降低HC、CO和NOx排放;预喷油量进一步增加(6~7 mg/cyc),NOx排放恶化,并且由于着火相位波动导致燃烧稳定性变差.改善双燃料发动机燃烧和排放特性一方面要增加预喷柴油在可燃混合气中的分布,增大柴油与可燃混合气混合的时间,改善混合气的活性,进而提高燃烧速率;另一方面要强化主喷柴油喷射对着火相位的控制,防止着火相位不一致而恶化燃烧稳定性. 相似文献