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火花点火式煤层气发动机的燃烧过程实验研究 总被引:1,自引:0,他引:1
对由S195柴油机改装得到的燃用变组分煤层气发动机进行了全面的测试和分析,包括缸内示功图、燃烧放热率、主燃期、点火提前角、火焰发展期以及最大压力循环波动等。结果表明:甲烷浓度、点火提前角、负荷的大小对火焰发展期、循环波动以及燃烧有着至关重要的影响。 相似文献
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火花点火式电控甲醇发动机非常规污染物的排放特性 总被引:7,自引:0,他引:7
在火花点火式电控甲醇发动机上,采用M85(85%甲醇和15%汽油的混合物)和M100(100%纯甲醇)两种甲醇燃料进行台架实验,通过气相色谱法检测和分析了甲醇和甲醛非常规污染物在发动机2 000 r/min和怠速时的排放特性,同时考察了三元催化反应器对非常规污染物的转化效率.实验结果表明:燃用甲醇燃料时,甲醇和甲醛排放量在无负荷时最大,而后,随负荷的增加而降低,到一定值后,随负荷的增加而升高,甲醇和甲醛排放量(体积分数)分别可高达450×10-6和150×10-6;催化后甲醇和甲醛的排放量均明显降低,其中甲醇的催化转化率可达到 95%以上,而甲醛的催化转化率与之相比略低.此外,怠速时发动机甲醇和甲醛的排放量也较高. 相似文献
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热裂解生物质气发动机燃烧特性试验 总被引:2,自引:0,他引:2
利用农林废弃物可控热裂解产生的生物质气作为火花点火发动机的燃料,测最火花点火生物质气发动机的示功图,分析了生物质气的燃烧放热特性.试验结果表明:发动机怠速点火性能较好,小功率时放热速度较慢,大功率时燃烧速度较快,燃烧较充分;火焰发展期随点火提前角的增大而变长,燃烧相位角随点火提前角、负荷的增大而提前,速燃期随负荷的增加、点火提前角的增大逐渐缩短;生物质气中的氢含量加快了生物质气发动机的燃烧速度. 相似文献
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LPG小型点燃式发动机怠速工况下微粒排放特性研究 总被引:1,自引:0,他引:1
介绍了LPG点燃式发动机在怠速工况下的微粒排放特性,试验在一台电控单缸机上进行。通过在不同混合气过量空气系数下的试验,发现理论空燃比附近微粒的排放量最少;在混合气浓区的微粒排放随着过量空气系数变小而增多;在混合气稀区的微粒排放随过量空气系数增大也略有增加。微粒的排放随点火提前角的推迟有先减小后增加的趋势。随转速的增加,粒径峰值逐渐向粒径增大变化。怠速工况下的微粒粒径主要集中在(23.7~133)nm。颗粒物排放浓度与HC排放的浓度在趋势上有较好的一致性。 相似文献
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发动机燃用煤层气的燃烧性能研究 总被引:1,自引:0,他引:1
为了分析发动机燃用煤层气时的燃烧特性,本研究在现有的单缸柴油机上加装点火系统和燃料喷射系统,将其改装成为适合燃用低热值气体的电控气体燃料发动机。采用台架试验研究与模拟分析相结合的研究方法,按照真实的煤层气的成分和各成分体积比例,配制出煤层气,并对发动机燃用不同组分的煤层气的性能进行了试验研究,对其燃烧特性进行了分析和总结。 相似文献
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以190型天然气发动机为对象,采集了发动机的示功图,分析了点火提前角及负荷对燃烧过程的影响规律。试验结果表明,在BTDC28℃A到BTDC36℃A范围内,最高燃烧压力和最大瞬时放热率以及缸内最高燃烧温度随点火提前角的增大而增大;BTDC33℃A点火提前角下最高燃烧压力和最大瞬时放热率以及缸内最高燃烧温度随负荷的增大而增大;火焰发展期随点火提前角增大而增大,随负荷增加而减小;50%燃烧相位角随点火提前角、负荷的增加而减小,速燃期随点火提前角的增大先增大后减小,随负荷增加呈减小趋势。 相似文献
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为了掌握汽油发动机空燃比特性的变化规律,本文通过发动机台架试验,研究了不同负荷下发动机空燃比的速度特性;研究了中高转速下发动机空燃比的负荷特性;研究了不同负荷和转速下汽车尾气排放物的排放浓度随过量空气系数的变化特点。 相似文献
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《International Journal of Hydrogen Energy》2022,47(63):26789-26797
The issues related to the reliability of hydrogen engines of unmanned vehicles and increasing the efficiency of using hydrogen as fuel when using the method of its production during the decomposition of hydrogen-containing molecules of liquid-phase organic compounds in a plasma discharge under the action of intense ultrasonic exposure are considered. Experiments have shown that as a result of decomposition in the acoustoplasma discharge of liquid hydrocarbons, solid-phase carbon-containing products are formed, chemical transformations occur in the liquid phase and hydrogen-containing combustible gas is formed. Hydrogen-containing gas can be used as fuel immediately after synthesis, i.e. it does not require separation, since in addition to hydrogen it contains only impurities of CO2 and water vapor. The purpose of the study is to formalize the basic conditions for tightening the control of mutual compliance with the efficiency of hydrogen engines of the same series in the conditions of their mass production. Methods of mathematical statistics and hardware-software modeling were used in the study. The term “unerroric of quality mutual compliance control” is introduced to describe a set of hardware and software tools for such control. The principle of in-depth testing of the technical condition of such engines of one series is described in a multidimensional formulation of the quality control problem for three of their operating parameters at once. The conditions for increasing the mutual correspondence of the measured values of such parameters in the conditions of serial production of hydrogen engines are formalized. 相似文献
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Linear and nonlinear analyses of the instabilities and distortion of liquid streams injected into a gaseous media are discussed. The various fundamental mechanisms and the predictive capabilities for the distortions are emphasized. Round jets, planar sheets, annular sheets, and conical sheets are discussed in detail. The balance between capillary and inertial forces is primarily examined. The method for simplifying the analyses in the case of thin liquid sheets is discussed. The capabilities for representing the droplet size distribution that follows the stream disintegration are outlined. 相似文献
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基于《水工混凝土掺用氧化镁技术规范》中的Ⅰ型氧化镁(MgO),研究了该型MgO膨胀剂(MEA)细度对掺粉煤灰水泥浆体膨胀性能的影响。即采用X射线衍射分析(XRD)及同步热分析(TG DSC)分析了掺MEA水泥浆体中MgO的水化性。结果表明,养护温度相同时,MEA的细度对水泥浆体内MEA中MgO的水化和水泥浆体的膨胀无显著影响,产生的膨胀均能补偿水泥浆体的收缩;MEA的细度可从试验设计采用的45 μm筛筛余15%左右增加到30%左右,这将有利于MEA生产企业的节能降耗。 相似文献
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使用ANSYS8.0软件对高速列车车轮进行了三维有限元分析,计算出车轮在直线、曲线和道岔条件下牵引、制动共6种工况时孔边薄弱部位的应力,分别通过Mises等效平均应力方法、Sines平均主应力方法和应力分量中考虑平均应力方法计算出应力在极值位置时的等效应力幅、等效平均应力,从而进一步算出车轮的安全系数,对其疲劳强度进行评定,并对3种方法进行了比较研究。 相似文献
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M.R. Salimpour M. SharifhasanE. Shirani 《International Communications in Heat and Mass Transfer》2011,38(1):93-99
This paper documents the geometric optimization of an array of circular and non-circular ducts. The optimization was carried out numerically using finite volume method. As optimal dimensions were independent of the array configuration, the numerical simulation was performed on a unit cell. Numerical optimization for circular, square and isosceles right triangle cross-sections of channels was performed. Based on the results of this investigation, some correlations were proposed to predict the optimal hydraulic diameter and dimensionless heat transfer per unit volume. In addition to examining the effect of pressure drop on these parameters, it was showed that among the different geometries of this study, square cross-section has the most efficiency for a given volume. The numerical results of the present study were compared with approximate results reported in the literature which a good agreement was observed. 相似文献
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本文对漫灰均温物体在常物性条件下对外辐射传热的Yong值计算建立了数学模型。通过与物体内能Yong公式的数值计算比较,得出了辐射能量的Yong值不大于内能Yong值的结论。从初步的热射Yong值计算公式发现。Yong与物体表面辐射率有关。 相似文献
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《International Journal of Hydrogen Energy》2022,47(83):35515-35526
The main purpose of this work is to propose a new method to evaluate the concentration distribution of the hydrogen jet by using a He–Ne laser through the jet. This research attempts to apply the expression of concentration Gaussian distribution, the refraction formula of inhomogeneous refractive index medium, and the concentration inversion function to disclose the displacement of the center of the laser spot at different heights in the gas jet. The spot images of the laser beam passing through the gas jet at three vertical heights z = 10d, 20d, 30d, and different radial positions are obtained. The radial spatial asymmetry of the gas jet is also found in the experiment. Finally, the calculated concentration distribution curve and the fluent simulation curve, it is found that the two results are very similar. Our findings show that the error between the concentration distribution of this method and the simulated concentration distribution reaches 2.43%. 相似文献
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General expressions for the heat of vaporization of mixtures at constant pressure; at constant temperature; and at constant pressure, temperature, and composition are proposed. The last one is related to the liquid-vapor interface where steady vaporization or condensation is taking place. Numerical examples by the proposed expressions are shown for binary mixtures of HCFC22(R22) and (HCFC123(R123) © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25(1): 12–24, 1996 相似文献