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直喷式柴油机燃烧过程模拟与分析(二) 总被引:1,自引:0,他引:1
利用IIVA-Ⅱ程序模拟计算直喷式柴油机燃用柴油时缸内的燃烧过程,如混合气形成过程、缸内温度场、主要有害物质NOx的生成浓度分布等。通过对直喷式柴油机燃用柴油时燃烧过程的模拟计算与分析,对模拟燃用绿色能源-二甲醚的燃烧过程提出了一些建议。 相似文献
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通过实测直喷式柴油机燃烧不同十六烷值柴油时的缸内压力示功图,以此计算出相应的燃烧放热规律。通过分析影响放热规律的有关参数,确定了对几项因子通过试验匹配来进行直喷式柴油机燃用低十六烷值柴油机的初步研究。以试验研究为基础,利用神经网络的非线性映射性能得出了燃用低十六烷值柴油机时几个参数的调整方案。 相似文献
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比较了柴油和丙烷的主要理化性能;在一台单缸直喷式柴油机上开展了燃用柴油和柴油/丙烷混合燃料时的发动机燃烧和排放特性研究.研究结果表明:在相同工况下,与燃用柴油相比,燃用柴油/丙烷混合燃料时的有效热效率增加,柴油/丙烷混合燃料的有效热效率随丙烷比例的增加而稍有增加,混合燃料的滞燃期和燃烧持续期随丙烷比例的增加而缩短;缸内最大压力,最大燃烧放热率,最高平均燃烧温度随丙烷比例的增加而增加.燃用丙烷柴油混合燃料可同时降低CO、HC和碳烟排放,但NOx排放有所增加. 相似文献
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对490Q直喷式柴油机进行了LPG/柴油双燃料的技术改造。在分别燃用纯柴油和柴油/LPG双燃料的情况下,研究了相应工况下发动机的动力性、经济性以及排放特性等性能。试验结果表明,加入一定比例的LPG可改变缸内燃烧过程,大幅度降低排气烟度,在一定程度上提高了燃油经济性。 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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直喷式柴油机缸内过程的能量可用性分析 总被引:1,自引:1,他引:1
本文以柴油机工作过程的热力学第一定律数值模拟为基础,应用热力第二定律分析一台直喷式柴油要的缸内过程的能量可用性。通过各过程的能量可用性平衡分析,定量地计算了能量作功能力和不可逆损失,并且与势和不第一定律的能量平衡进行了比较;分析计算了直喷式柴油机的循环喷油量、燃烧开始角、燃烧持续期、燃烧品质指标及气缸绝热对缸内能量可用性和热力学第一定律、第二定律热效率的影响。 相似文献
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周斌 《柴油机设计与制造》2011,17(4):6-11
应用三维CFD仿真软件AVL FIRE对CY4102直喷式柴油机的燃烧过程进行了数值模拟计算,再现了缸内流体的运动过程、湍流参数的变化、燃油粒子的空间分布、燃烧过程的进展状况、传热过程以及缸内温度场的分布等,结果表明:随着喷油提前角的增大,滞燃期变长,最高平均温度、压力和放热率峰值均增大,且其对应的曲轴转角均有前移趋势... 相似文献
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The photovoltages and photocurrent in a photogalvanic cell containing flavin mononucleotide (FMN) and a reducing agent, ethylenediaminetetraacetic acid (EDTA) have been determined and found to be appreciable. The efficiency of the cell has been estimated to be ~ 0-048 percent. The electrochemical behaviour of FMN in the presence of EDTA has been examined by cyclic voltametry. 相似文献
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《Energy》1997,22(6):601-614
A criterion, based on optimization principles, for determining the SAT setpoint in VAV systems is presented. It is generally accepted that conventional SAT reset controls (SATRC), bounded by either space humidity or ductwork size, will save cooling and/or heating energy. How-ever, the ventilation consequences and penalty resulting from increased fan power have generally been overlooked. Ventilation is impacted since changes in the SAT setpoint change the primary airflow rate and the operation of economizer cycles, i.e. the distribution of fresh outdoor air (OA). These changes may result in extra energy demand and ventilation inefficiency if the reset criterion is not appropriate. This optimization concept simultaneously reduces energy consumption and meets ventilation requirements. Simulation results illustrate that the use of the optimized SATRC saves more energy than a conventional one. 相似文献
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Zaixing Yang Fangyi ChengZhanliang Tao Jing LiangJun Chen 《International Journal of Hydrogen Energy》2012
This paper reports on a hydrogen storage material of poly(methyl acrylate) and methylamine borane (PMA/MeAB) composite, which is synthesized by a simple solution-blending process at room temperature. The thermal decomposition process of the as-prepared composite is investigated by temperature programmed desorption/mass spectrometer (TPD/MS), thermogravimetry (TG) measurements and water displacement method. It is found that PMA/MeAB100 (100 mg PMA with 100 mg MeAB) starts to release H2 at the temperature of 90.5 °C with the dehydrogenation peak centered at 120.7 °C. This is about 20 °C lower than that of neat MeAB. Meanwhile, the evaporation of MeAB and the volatile byproducts from the dehydrogenation stage of PMA/MeAB100 are also suppressed. The present result shows that the dehydrogenation property of MeAB is enhanced by using PMA/MeAB composite. 相似文献
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Tamunosaki Graham Douglas Andrew J. CrudenDavid Infield Amitava RoyPeter Hall 《International Journal of Hydrogen Energy》2011,36(13):7791-7798
The use of zero-gap cell geometry and development of low cost electrodes are some of several attempts on reducing cost and increasing efficiency of electrolytic hydrogen production. This study involves the synthesis of an electrode consisting of resorcinol-formaldehyde (RF) carbon aerogels of high surface area (>700 m2/g) and nano-pore sizes (4 nm) thermally deposited on molybdenum metal. The hydrogen evolution reaction (HER) characteristics of the Mo-RF electrode involving an intermediate ‘spectator metal-oxo’ compound and its Volmer-Heyrovsky electro-catalyst property are described. The physical and morphological structure of the Mo-RF has been shown through SEM images thus confirming the effectiveness of the synthesis method. Polarisation measurement of the Mo-RF electrode in 30% (by vol) KOH solution at 298 K indicates its potential applications in alkaline electrolysers. It is anticipated that the use of Mo-RF electrode offers economic benefit of reduced capital cost investment compared with other electrodes such as Pt-C previously used in electrolysers. 相似文献
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Yadigar Gülseven Erol Taşal İsa Sıdır Tayyar Güngör Halil Berber Cemil Öğretir 《International Journal of Hydrogen Energy》2009
The electronic absorption spectra of 4-((2-ethylphenyl)diazenyl)benzene-1,3-diol and 2-((2-ethylphenyl)diazenyl)benzene-1,3,5-triol molecules in the nine different solvent variable electronic characters have been recorded. The solvent dependent maximum absorption band (π–π* transitions) shifts, νmax, were analyzed using a wide range of parameters such as refractive index, dielectric constant and Kamlet–Taft parameters [hydrogen bond donating ability (α) and hydrogen bond accepting ability (β)]. The electronic transitions are assigned and the solvent-induced spectral shifts have been analyzed in relation to the different solute–solvent interaction mechanism using computational chemistry. The intermolecular interaction types in the azobenzene derivatives solutions have been established on the basis of a multiple linear regression analysis. The fitting coefficients obtained from this analysis allowed us to estimate the contribution of each type of interactions to the total spectral shifts in the studied solutions. 相似文献
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《Journal of power sources》1988,22(1):69-76
Metal dibenzo(b,i)(1,4,8,11)tetraaza(14)annulene-iodine charge transfer complexes show high electrical conductivity even in the presence of a large excess of molecular iodine. Investigations of the behaviour of these materials as cathodes in lithium-iodine batteries is reported. The ease of preparation and handling as well as the discharge characteristics make it a potential alternative to the P2VP poly(2-vinylpyridine)-iodine system. 相似文献
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