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车用增压二甲醚发动机燃烧和排放特性的试验研究 总被引:8,自引:3,他引:5
在一台D6114ZLQB柴油机上进行了燃用二甲醚(DME)的燃烧和排放特性的试验研究。研究结果表明:二甲醚发动机的外特性转矩特别是低速转矩比柴油机高;二甲醚喷油延迟角比柴油大,最高爆发压力、最大压力升高率、燃烧噪声比柴油低;二甲醚扩散燃烧速率比柴油快,燃烧持续期比柴油短。和柴油机相比,二甲醚发动机的NO,排放显著下降,其欧洲稳态测试循环(ESC的NOx排放比原柴油机降低41.6%;二甲醚发动机在全工况范围内碳烟排放为零。 相似文献
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ZS195柴油机燃用二甲醚(DME)-柴油混合燃料的试验研究 总被引:10,自引:0,他引:10
二甲醚粘度低,会使高压供油系统产生泄漏及早期磨损。在二甲醚中添加低比例的柴油(简称二元燃料),其柴油既参与燃烧,又相应提高了混合燃料的粘度。首先对二甲醚添加低比例的柴油进行优化并对柴油机供油量、供油提前角和针阀开启压力进行优化匹配,然后对ZS195柴油机燃用二元燃料进行试验研究。结果表明:在ZS195柴油机上燃用二元燃料,其功率和转矩略优于原柴油机,发动机在全负荷范围内接近无烟排放,NOχ大幅度下降。试验还表明,采用这种二元燃料可使供油系统长期稳定地工作。 相似文献
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直喷柴油机燃用二甲醚的试验研究 总被引:20,自引:1,他引:19
在直接喷射式柴油机上进行了燃用二甲醚的试验研究,对柱塞有效行程和柱塞直径、供油提前角、喷油压力、进气涡流比、喷嘴型式等燃烧系统主要参数对发动机功率和热效率的影响进行了研究,在燃料供给系统中增加燃油输送泵,消除了气阻,发动机可以在宽广的转速和负荷范围内稳定运行,发动机热效率比原机高3% 。在优化燃烧系统参数的基础上对示功图和排放的测量及计算表明:二甲醚发动机最高爆发压力、最大压力升高率和 N Ox 排放均低于原机,烟度排放为0。试验结果显示了直喷式柴油机燃用二甲醚在降低排放方面的优越性能。 相似文献
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廖水容 《小型内燃机与摩托车》2011,40(6):79-82
在一台车用单缸直喷柴油机上进行了燃用二甲醚的试验研究,结果表明:二甲醚发动机的动力性及排放性能优于柴油机.基于二甲醚燃烧数值仿真计算平台,建立氮氧化物模型.利用建立的平台计算二甲醚发动机在不同负荷下的动力及排放性能.得出:仿真结果与试验结果相同.研究结果表明:二甲醚发动机的NOx排放比柴油机大幅度降低,二甲醚发动机可以完全消除碳烟排放,二甲醚是一种可以替代柴油的理想清洁燃料. 相似文献
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直列泵柴油机燃用二甲醚(DME)的燃烧排放特性分析 总被引:1,自引:0,他引:1
在一台增压直列泵柴油机进行了燃用柴油和二甲醚的试验,实测了缸内压力,并据此计算了燃烧放热率,对动力性及排放特性进行了对比分析。结果表明:发动机燃用二甲醚后,功率和扭矩都有所提升,选用9°CA和12°CA供油提前角时,在不同转速下的NOx排放均低于柴油;在全负荷情况下的最高燃烧压力和峰值放热率均低于柴油;二甲醚的喷油量是柴油的两倍,但二甲醚的燃烧速度高于柴油,所以二者的燃烧持续期相差不大;选用6孔的喷嘴比5孔喷嘴燃烧更加充分,但是较高的最高燃烧压力和燃烧放热律也使得NOx排放增加。 相似文献
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二甲基醚(DME)燃烧特性研究 总被引:22,自引:3,他引:19
作者在定容燃烧弹上用火焰直接成像法研究二甲基醚 (DME)燃烧过程 ,研究了 DME的滞燃期和火焰传播特性以及不同环境温度和压力对燃烧过程的影响。研究结果表明 ,DME的滞燃期比柴油短 ,燃烧室内的温度和压力升高时 ,滞燃期缩短 ;DME的着火位置靠近喷嘴一侧 ,柴油与 DME的体积相同时 ,DME的燃烧持续期比柴油短 ;DME的燃烧火焰亮度比柴油小 ,表明 DME的燃烧温度比柴油低。燃烧后期 ,燃用 DME时 ,喷嘴有明显的泄漏现象。此外 ,作者在单缸直喷式柴油机上进行了燃用 DME的燃烧特性试验研究 ,研究结果表明 ,DME的预混合燃烧放热率比柴油低 ,缸内最大爆发压力和最大压力升高率比柴油低。由于喷油持续期延长 ,DME的燃烧持续期比柴油长 ,在上止点后 80° CA出现一个较大的放热峰值。 相似文献
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An experimental study of a turbocharged diesel engine operating on dimethyl ether (DME) was conducted. The combustion and emission characteristics of the DME engine were investigated. The results show that the maximum torque and power of DME are greater than those of diesel, particularly at low speeds; the brake specific fuel consumption of DME is lower than that of diesel at low and middle engine speeds, and the injection delay of DME is longer than that of diesel. However, the maximum cylinder pressure, maximum pressure rise rate and combustion noises of the DME engine are lower than those of diesel. The combustion velocity of DME is faster than that of diesel, resulting in a shorter combustion duration of DME. Compared with the diesel engine, NOx emission of the DME engine is reduced by 41.6% on ESC data. In addition, the DME engine is smoke free at any operating condition. 相似文献
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This article is a condensed overview of a dimethyl ether (DME) fuel application for a compression ignition diesel engine. In this review article, the spray, atomization, combustion and exhaust emissions characteristics from a DME-fueled engine are described, as well as the fundamental fuel properties including the vapor pressure, kinematic viscosity, cetane number, and the bulk modulus. DME fuel exists as gas phase at atmospheric state and it must be pressurized to supply the liquid DME to fuel injection system. In addition, DME-fueled engine needs the modification of fuel supply and injection system because the low viscosity of DME caused the leakage. Different fuel properties such as low density, viscosity and higher vapor pressure compared to diesel fuel induced the shorter spray tip penetration, wider cone angle, and smaller droplet size than diesel fuel. The ignition of DME fuel in combustion chamber starts in advance compared to diesel or biodiesel fueled compression ignition engine due to higher cetane number than diesel and biodiesel fuels. In addition, DME combustion is soot-free since it has no carbon–carbon bonds, and has lower HC and CO emissions than that of diesel combustion. The NOx emission from DME-fueled combustion can be reduced by the application of EGR (exhaust gas recirculation). This article also describes various technologies to reduce NOx emission from DME-fueled engines, such as the multiple injection strategy and premixed combustion. Finally, the development trends of DME-fueled vehicle are described with various experimental results and discussion for fuel properties, spray atomization characteristics, combustion performance, and exhaust emissions characteristics of DME fuel. 相似文献
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Junhua WU Zhen HUANG Xinqi QIAO Jun LU Junjun ZHANG Liang ZHANG 《Frontiers of Energy and Power Engineering in China》2008,2(1):79-85
An experimental study of a turbocharged diesel engine operating on dimethyl ether (DME) was conducted. The combustion and
emission characteristics of the DME engine were investigated. The results show that the maximum torque and power of DME are
greater than those of diesel, particularly at low speeds; the brake specific fuel consumption of DME is lower than that of
diesel at low and middle engine speeds, and the injection delay of DME is longer than that of diesel. However, the maximum
cylinder pressure, maximum pressure rise rate and combustion noises of the DME engine are lower than those of diesel. The
combustion velocity of DME is faster than that of diesel, resulting in a shorter combustion duration of DME. Compared with
the diesel engine, NO
x
emission of the DME engine is reduced by 41.6% on ESC data. In addition, the DME engine is smoke free at any operating condition.
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Translated from Transactions of CSICE, 2006, 24(3): 193–199 [译自: 内燃机学报] 相似文献
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使用KIVA-3V对增压柴油机和二甲醚发动机标定功率点的缸内燃烧过程与NOx排放进行了数值模拟研究.研究结果表明:计算所得的气缸压力和放热率曲线与实测值吻合较好.对缸内燃烧的温度分布计算表明:柴油燃烧滞燃期为2.5 °CA左右,二甲醚为1.5 °CA.柴油燃料着火始于喷雾前端两侧,在燃烧初期,其高温区分布在喷雾前端一侧,且在燃烧室内气流作用下沿垂直于喷雾方向扩散;二甲醚的着火点位于喷嘴附近,随喷雾的进行,其燃烧高温区从喷嘴附近一直延伸到喷雾前端,呈现狭长的高温带.在扩散燃烧后期,与柴油相比,二甲醚燃烧温度分布较均匀,且最高温度比柴油低.选用的9步NOx生成机理可较好地预测发动机实际运行中NOx排放水平. 相似文献