共查询到18条相似文献,搜索用时 234 毫秒
1.
2.
本文通过自行研制的多孔介质燃烧实验系统,研究了液体燃料在热多孔介质中的燃烧可行性及其燃烧特性.燃烧系统包括燃烧室、供气系统、供油系统和测量系统等,该系统分别以气体和液体作为燃料,先通过多孔介质内的预混合燃烧对多孔介质固相进行预热,然后喷入液体燃料,实现燃烧,实验证实了液体燃料在热多孔介质内汽化及自维持燃烧的可行性,并讨论了空气量和喷油量等对燃烧室温度的影响. 相似文献
3.
4.
5.
6.
应用预蒸发技术燃烧液体燃料 总被引:3,自引:1,他引:2
本文介绍了一种燃烧液体燃料的新技术-预蒸发燃烧技术:通过分离液体燃料的蒸发过程和燃烧过程,实现液体燃料的“气体化”燃烧;重点介绍利用液体燃料着火前存在的冷焰燃烧现象实现燃料预蒸发的技术原理。与传统的燃烧技术相比,液体燃料的预蒸发燃烧具有高效率、低噪音、低有害污染物特别是NOx排放、和易调节等优点。 相似文献
7.
本文以浮力修正的k-8湍流流动模型为基础,选用EBU的Magnussen版本的湍流燃烧模型,对多孔燃料床非定常燃烧现象进行数值模拟,所得结果定性合理。 另外,论文采用了空度的方法来处理多孔燃料床,同时考虑了研究体系内有源存在的情况,并对相应的方程进行了必要的修正,由于缺乏必要的实验数据,本文的计算结果没能与实验进行对比。 相似文献
8.
在开源计算流体软件OpenFOAM环境下,将基于欧拉方法的Σ-Y喷雾模型与非稳态火焰面/反应进度变量湍流燃烧模型相耦合,发展用于高温高压环境中液体燃料喷雾湍流燃烧高精度计算模型,分别对非燃烧和燃烧工况下的五种典型参比燃料(Primary Reference Fuel,PRF)的燃油喷射雾化与湍流燃烧过程开展数值研究。结果表明:该新型耦合模型能够准确的预测PRF燃料的喷雾和着火燃烧特性;所开发的重构数值喷雾纹影图像和燃烧OH*图像处理方法能够很好地捕捉到试验的滞燃期、火焰浮起长度及喷雾火焰结构;研究揭示了不同比例的PRF燃料对喷雾及着火燃烧过程的影响特性,为替代燃料在发动机上的高效应用提供了理论指导。 相似文献
9.
10.
利用5 kW鼓泡流化床实验装置,以小麦秸秆为燃料,以石英砂为床料,进行燃烧实验,在27~800℃温度范围内,对实验前后床料的最小流化速度进行研究。结果表明:生物质流态化燃烧后,床料表面粘附熔融物;常温条件下,熔融物对床料最小流化速度影响不明显,随着温度升高,石英砂床料最小流化速度降低,在温度大于500℃条件下,实验后床料的最小流化速度明显增大;床料表面粘附物高温条件下熔融是引起流化特性改变的根本原因。 相似文献
11.
水雾与可燃多孔介质火焰相互作用的实验研究 总被引:2,自引:0,他引:2
采用非传播扩散火焰形式,研究了固体可燃多孔介质中水雾-火焰的相互作用,探讨了床层厚度、多孔介质粒度以及燃料预燃时间对水雾灭火效果的影响。结果表明,随着预燃时间增长,水雾停止后床层内部可能发生闷烧现象,随着燃料粒度的减小,这种闷烧几率反而降低。这表明,固体火焰与水雾的相互作用有其独特之处。 相似文献
12.
对Solar低排放预混燃烧系统的燃烧稳定性进行了数值研究.应用非定常N-S方程、雷诺应力紊流模型及涡团耗散燃烧模型,数值模拟了该类型燃烧器在不同的燃料空气供给条件下的气流流动特性和压力振荡特性,并给出了不稳定发生时压力和速度振荡的幅值和频率.根据供给条件的不同,燃烧可以是稳定的或是不稳定的,取决于燃料到火焰前沿的迟滞时间.采用CFD方法,可精确地获得燃料到火焰前沿的迟滞时间,证实了所采用的模型能够精确预测不稳定燃烧的出现及振荡特性.通过调整燃料与空气的供给条件,可使振荡激励或阻尼. 相似文献
13.
Masato Mikami Kazuhiro Yamamoto Osamu Moriue Naoya Kojima 《Proceedings of the Combustion Institute》2005,30(2):2021-2028
Gas turbines, liquid rocket motors, and oil-fired furnaces utilize the spray combustion of continuously injected liquid fuels. In most cases, the liquid spray is mixed with an oxidizer prior to combustion, and further oxidizer is supplied from the outside of the spray to complete diffusion combustion. This rich premixed spray is called “partially premixed spray.” Partially premixed sprays have not been studied systematically although they are of practical importance. In the present study, the burning behavior of partially premixed sprays was experimentally studied with a newly developed spray burner. A fuel spray and an oxidizer, diluted with nitrogen, was injected into the air. The overall equivalence ratio of the spray jet was set larger than unity to establish partially premixed spray combustion. In the present burner, the mean droplet diameter of the atomized liquid fuel could be varied without varying the overall equivalence ratio of the spray jet. Two combustion modes with and without an internal flame were observed. As the mean droplet diameter was increased or the overall equivalence ratio of the spray jet was decreased, the transition from spray combustion only with an external group flame to that with the internal premixed flame occurred. The results suggest that the internal flame was supported by flammable mixture through the vaporization of fine droplets, and the passage of droplet clusters deformed the internal flame and caused internal flame oscillation. The existence of the internal premixed flame enhanced the vaporization of droplets in the post-premixed-flame zone within the external diffusion flame. 相似文献
14.
用单脉冲交叉相干反斯托克斯喇曼散射技术测量了两种不同固体燃剂的瞬态燃烧场的温度。对燃烧场进行了优化,给出了在燃烧场中取得的部分典型单脉冲CARS光谱及其理论拟合结果,得到了燃烧场的温度及其随高度的分布;稳定燃烧时两种燃剂燃烧场的温度基本保持不变,平均值分别为2 260,2 090K;测量了实验的纵向空间分辨率。结果表明,BOXCARS技术能较好地完成复杂的瞬态燃烧场温度的测量工作。 相似文献
15.
燃烧法合成碳纳米管的实验方案设计 总被引:2,自引:0,他引:2
碳纳米管是一种新型的碳材料,其合成方法多种多样。燃烧法是一种新兴的合成方法,燃烧过程提供用于碳纳米管生长的高温环境,同时也提供足够的烃原料。目前,用于合成碳纳米管的原料包括气体燃料和液体燃料,火焰类型主要有层流扩散火焰、逆流扩散火焰和预混火焰等。影响炭纳米管火焰合成的因素主要有气体成分,温度,催化剂,燃氧比和采样条件。我们采用甲烷扩散火焰用于实验研究炭纳米管的合成条件。实验系统包括扩散火焰喷嘴,混和段,质量流量计,取样探针和基板,气源。内径5 mm的喷嘴与内径100 mm的钢筒同轴。实验测得在气量为0.20 SLM时火焰高度为 3.5 cm。涂覆有催化剂的基板水平朝下置于火焰中采样,并将采集的样品进行电镜分析。本文还对燃烧法合成碳纳米管的机理进行了分析。 相似文献
16.
S. V. Alekseenko I. S. Anufriev M. S. Vigriyanov V. M. Dulin E. P. Kopyev O. V. Sharypov 《Thermophysics and Aeromechanics》2014,21(3):393-396
The lab-scale burner device with proprietary design was used for combustion of diesel fuel in a steam-enhanced regime. This operation mode ensures drastic intensification of liquid hydrocarbon combustion due to supply of superheated steam jet to the combustion zone. The particle image velocimetry technique was used for study of velocity field in the burner flame. The method of seeding of flow zone with new kind of tracers (micro-sized silica particles produced from silicon oil added to liquid fuel) was tested. 相似文献
17.
《Proceedings of the Combustion Institute》2023,39(3):3117-3126
Effects of fuel jet penetration height on supersonic combustion behaviors were investigated experimentally in a supersonic combustion ramjet model combustor at a Mach speed of 2 and at a stagnation temperature of 1900 K. The jet-to-crossflow momentum flux ratio was varied to control the fuel-jet penetration height, using several injectors with different orifice diameters: 2, 3, and 4 mm. First, transverse nitrogen jets were observed to identify a relationship between the fuel jet penetration height and the momentum flux ratio by focusing Schlieren photography. Then, supersonic combustion behaviors of ethylene were investigated through combustion pressure measurements. Simultaneously, time-resolved images of CH* chemiluminescence and shadowgraphs were recorded with high-speed video cameras. Furthermore, a morphology of supersonic combustion modes was investigated for various equivalence ratios and fuel penetration heights in a two-dimensional latent space trained by the shared Gaussian process latent variable models (SGPLVM), considering CH* chemiluminescence images and the shock parameters. The results indicated that the penetration height of nitrogen jets was a function of the jet momentum flux ratio; this function was expressed by a fitting curve. Five typical combustion modes were identified based on time-resolved CH* chemiluminescence images, shadowgraphs, and pressure profiles. Even for a given equivalence ratio, different combustion modes were observed depending on the fuel penetration height. For an injection diameter of 3 and 4 mm, cavity shear-layer and jet-wake stabilized combustions were observed as the scram modes. On the other hand, although the cavity shear-layer and lifted-shear-layer stabilized combustions were observed, no jet-wake stabilized combustion was observed for an orifice diameter of 2 mm. Fuel penetration heights above the cavity aft wall were expected to affect the combustion behavior. Finally, a morphology of the supersonic combustion modes was clearly shown in the two-dimensional latent space of the SGPVLM. 相似文献
18.
Hiroshi Nomura Hiroshi Iwasaki Yusuke Suganuma Masato Mikami Masao Kikuchi 《Proceedings of the Combustion Institute》2011,33(2):2013-2020
Combustion experiments of fuel droplet array in fuel vapor-air mixture were performed at microgravities to investigate growth mechanism of group combustion of fuel droplets. A 10-droplet array was inserted into the test section filled with a saturated fuel vapor-air mixture as a simple model of prevaporized sprays. Gas equivalence ratio of the fuel vapor-air mixture was regulated by the test section temperature. n-Decane droplets of 0.8 mm in the initial diameter were suspended at the crossing points of 10 sets of X-shaped suspenders. The first droplet was ignited by a hot wire to initiate flame spread along a fuel droplet array. Flame spread speed was obtained from the history of the leading edge position of a spreading flame. Effects of droplet spacing and gas equivalence ratio on the flame spreading behavior and the flame spread speed were examined. The droplet spacing and the gas equivalence ratio were varied from 1.6 to 10.2 mm and from 0.2 to 0.7, respectively. The gas equivalence ratio has little effect on the relationship between the flame spreading behavior and the droplet spacing. The flame spread speed increases as the increase in the gas equivalence ratio at all droplet spacings. The influence of the gas equivalence ratio on the flame spread speed becomes strong as the increase in the droplet spacings. The flame spread speed increases as the increase in the droplet spacing, and then decreases. The maximum flame spread speed appears in the range from 2.4 to 3 mm at all gas equivalence ratios. 相似文献