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针对自然吸气直喷式柴油机,试验研究了喷油嘴压力室容积、喷油压力、喷孔直径、喷孔锥角、喷油提前角和空燃比等对HC排放的影响。试验结果表明,减少喷油嘴压力室容积,提高喷油压力,减小喷孔直径,适当加大喷孔锥我和小负荷时喷油提前角域可大幅度降低柴油机HC排放。 相似文献
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通过对一批故障喷油器样本的测试分析,找到了造成该批喷油器故障的主要原因,讨论了各种喷油器故障现象及其影响柴油机正常工作的机理,进行了液体挤压研磨去除喷孔毛刺的试验,比较了液体挤压研磨去除毛刺前后喷油嘴各喷孔流量和相应喷雾照片的变化。 相似文献
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喷油嘴四喷孔流量自动检测系统 总被引:2,自引:1,他引:1
介绍了喷油嘴四喷孔流量自动检测系统的工作原理 ,给出了系统硬件和软件设计。该自动检测系统具有检测数据可靠 ,测量速度快 ,稳定性高 ,重复性好的特点 ,能够满足四喷孔流量检测科学研究的需要 相似文献
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一、漏装垫片一台S195型柴油机多次咬死喷油嘴。机手拆下喷油器检查,发现漏装了喷油器与机体间的垫片,改变了喷油嘴与启动喷孔的相对角度,喷油嘴伸出燃烧室过长,影响了燃烧室里燃油与空气的混合燃烧,致使积炭加重,咬死喷油嘴。后重新装上垫片,故障即被排除。 相似文献
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1喷油器的分类与结构喷油器一般分为开式和闭式2种。开式喷油器的高压油腔通过喷孔直接与燃烧室相通,而闭式喷油器则在其间加装针阀隔断。车用柴油机绝大多数采用闭式喷油器,喷油器主要由喷油嘴体和喷油嘴2部分组成,根据 相似文献
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《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
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感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
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The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献
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从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性,认为在缺水不可避免的情况下,对供水进行优化调度可以减小缺水带来的损失,产生较好的减灾效益,特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性,提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献