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介绍了数值模拟技术在发动机研究过程中的重要作用,以捷达前卫发动机为基础,应用GT-POWER软件建立了发动机工作过程模型,通过实验验证了该模型的可靠性.在此基础上对配气正时进行了模拟计算,计算结果表明在高转速时适当增大进气迟闭角对提高发动机的性能有利,与理论分析一致. 相似文献
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中林 《林业机械与木工设备》1993,(1)
自本世纪60年代以来,世界各国特别是工业发达国家,对降低油锯振动和噪声、减轻重量、改善排放、保障安全作业等主要方面进行了大量的研究工作,并取得了较大成效.①利用现代技术,改进动力系统.德、日、瑞典等国家都把电子技术应用于油锯发动机,采用电子点火.瑞典两家公司还分别开发油锯用发动机的增压式化油器技术和高效空气净化技术.从而减少了发动机进气中所含杂质和清洗空滤器的次数,同时改善了发动机的性能.目前,微电脑技术也得到了初步应用. 相似文献
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基于乙醇汽油和汽油的空燃比的差异以及对发动机性能的影响,在不改变发动机结构参数的情况下,试验研究发动机燃用93号E10和93号汽油的基本性能。从试验可以得出发动机燃用乙醇汽油与汽油的动力性、经济性及排放特性对比。在中、低转速动力性下降,在较高转速动力性相当;燃油经济性在低、中负荷略有下降,在高负荷略好于汽油;在怠速工况下,乙醇汽油会降低汽油机的CO、HC和NOx的排放。针对燃料空燃比对发动机的性能影响,对发动机燃用乙醇汽油的空燃比的控制进行研究。对发动机的喷油器喷孔直径、喷油脉宽及喷油量的定量修正,为发动机燃用乙醇汽油的空燃比控制提供参考。 相似文献
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对醇类燃料特性及其应用现状的分析研究表明,低浓度醇类燃料适合在不改变发动机结构的情况下使用;结合二冲程小型发动机的特点和使用情况,得出低浓度醇类燃料适合作为其替代燃料;通过对醇类燃料作为二冲程小型发动机燃料的可行性分析可知,燃烧醇类混合燃料可提高二冲程小型发动机的能量利用率、减少其尾气排放和降低排放温度。 相似文献
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梁学志 《林业机械与木工设备》1990,(6)
解放CA141K_2型柴油汽车上安装的是CA6110型柴油发动机。使用中,由于曲轴正时齿轮打坏,换装新件后,在对气门间隙时出现了麻烦。也就是把定时齿轮按着齿轮记号对好后,可是在一摇曲轴检查时,发现已对好的气门间隙改变了。虽然发动机可以启功着火,但发动机“缺腿”, 相似文献
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王建康 《林业机械与木工设备》2009,37(7):56-58
阐述了柴油发动机的发展进程,分析了柴油汽车排放物产生的机理和化学成分,并对柴油汽车排放物的环保检测标准和检测方式等进行了深入探讨。 相似文献
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沼气燃料在小型柴油机上燃用措施的试验研究 总被引:6,自引:0,他引:6
介绍沼气成份、性质、燃烧特性和沼气净化,分析在柴油机上燃用沼气的影响因素,及采用的技术措施。通过对改装的沼气一柴油双燃料发动机性能和原机对比试验研究,证明在原机压缩比不变,增大进气量,控制引燃量及增大供油提前角等技术措施下,柴油机能取得明显节油效果,其动力性接近原机指标。 相似文献
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A study was done using eight different logging machines (harvesters and forwarders) in clear-felling operations to quantify the associated fuel consumption, and to define the inherent relationship between engine output power and fuel consumption. Exhaust emissions were also calculated on the basis of mean fuel consumption values, obtained by measurements, and from the developed regression and correlation model for diesel and rapeseed methyl ester (RME) fuels. The calculation considered exhaust emissions associated with the manufacture, distribution, and combustion of the respective fuels. It was found that carbon dioxide emissions amounted to 9.63 kg/m3 of delivered timber for diesel fuel, and to 10.64 kg/m3 for RME. It was also found that when using RME only 2.82 kg/m3 of carbon dioxide emissions originated from fossil resources, therefore, it is only this amount that can be deemed an environmental load, confirming RME as a lesser environmental pollutant. 相似文献
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We investigated the vulnerability of xylem to embolism and the seasonal occurrence of xylem embolism in Italian alder (Alnus cordata Loisel.) by acoustic and hydraulic methods. Wood anatomy was also studied. More than eighty percent of the vessels were less than 50 mm long and no vessels were longer than 120 mm. Mean vessel diameter was 48 micro m. Ultrasound acoustic emissions from root and branch segments dehydrating in air followed a similar pattern: in both tissues, emission peaks were recorded when the relative water content of the xylem was around 0.2. In branches dehydrating in air, xylem embolism increased linearly as water potential decreased. In trees in the field, more than 80 percent of hydraulic conductivity was lost in the tree crowns during winter. Recovery from winter embolism occurred mostly before bud burst. In summer, xylem embolism was low (< 30%) and acoustic emissions from roots, stem and branches of trees in the field were also low. 相似文献
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为了实现地沟油的有效回收利用,采用热裂解和催化酯化工艺制备了地沟油生物燃料油,并把制得的燃料油与0#柴油调合进行台架试验测试。结果表明:通过热裂解反应,油品的物质组成发生了变化,热裂解油主要组分为C10~C18的烷烃、烯烃和羧酸等,其中烃类质量分数占64%。裂解油再经过催化酯化反应,油品的燃料性能进一步提高,所制得的生物燃料油性能如下:酸值0.29 mg/g,黏度2.58 mm2/s,热值为44 MJ/kg,冷凝点-7℃,冷滤点-3℃,各性能都符合国家生物柴油标准。台架试验测试混合燃料的动力性能和排放性能,数据表明地沟油生物燃料油对于柴油机动力性能影响甚微,排放尾气环保性能更优。 相似文献
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1 INTRODUCTIONAll plants emit a wide range of volatile compoundssuch as nitric oxide, carbon monoxide, and non-methane volatile organic compounds, the latestoften referred to biogenic volatile organiccompounds (BVOC), mainly terpenoid or terpene(isoprene, monoterpenes). BVOC emissions havereceived increased scientific attention in the lasttwo decades because BVOCs are highly reactiveand, thus, may profoundly influence the chemicaland physical properties of the atmosphere(Kavouras, et … 相似文献
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