共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
3.
对ZWR混凝土节能增效剂在商品混凝土中的应用性能进行试验研究与工程应用,结果表明,该节能增效剂在保证混凝土综合性能的情况下,掺量为胶凝材料的0.6%~ 1%,可降低水泥用量10%~ 15%,明显降低了生产成本.使用增效剂后,在不改变工作性能和结构性能的前提下,混凝土开裂的风险减少,总碱量降低. 相似文献
4.
5.
6.
生物柴油特性及作为混合燃料添加剂的研究 总被引:5,自引:0,他引:5
论述了生物柴油优越的理化特性,可作为柴油的替代燃料,并讨论了生物柴油作为乙醇(甲醇)与柴油或汽油混合燃料的添加剂情况.通过溶解度测定及三相图实验数据表明生物柴油作为乙醇与柴油添加剂,促溶效果较好;对于生物柴油-汽油-乙醇体系来讲,三者可以任意比例混合,可改善汽油的燃烧性能;对于生物柴油-柴油-甲醇体系,效果不理想. 相似文献
7.
针对四川石化公司加氢裂化装置原料供应不足,催化裂化装置柴油十六烷值不合格,中国石油四川石化270万吨/年加氢裂化装置掺炼催化重柴油运行。加氢裂化装置原料变更后,经过操作条件的调整,生产运行平稳,产品分布合理,达到节能降耗的目标。生产了满足国Ⅳ标准的高品质油品。 相似文献
8.
9.
10.
新型农药增效剂CN的应用研究许世祥(石家庄市化工研究所石家庄市050031)增效剂CN是由河北省高碑店市新光化工厂研制的,1996年以来,我们对该增效剂做了大量药效试验,结果列于表1、表2。处理防治效果/%马唐狗尾草牛筋草稗草马齿苋鸭跖草乙阿+CN1... 相似文献
11.
12.
13.
14.
Mixture formation plays an important role in the diesel reforming process. It is important to maintain proper O2/C and H2O/C ratios to avoid hot spots and coking. Fuel must be completely evaporated before entering the reaction zone in order to prevent catalyst damage by coking. Computational fluid dynamics (CFD) is used to optimise the mixing process. Turbulent mixing, diesel spray injections and evaporation and simplified chemical reactions have been calculated. This revealed critical parts of the existing construction. However, experimental verification is necessary. To identify thermodynamic conditions for a possible carbon formation process, experiments with idealised model fuels as well as with real diesel fuel were carried out. Flow visualisation experiments serve for the verification of the CFD simulations. Quartz glass reactors as models of the reformers were operated under real mixing temperatures (400 °C) to observe the effect of the flow profile on fuel sprays. Experiments with coloured fuels were used to visualise the flow and concentration profiles in the mixing chamber. Results were compared with CFD models. Two patented reformers were designed as a result of the CFD optimisation. These were operated for 500 h and 1,000 h respectively with a commercially available diesel, showing very promising results. 相似文献
15.
Hydrogen, for the operation of a polymer electrolyte fuel cell, can be produced by means of autothermal reforming of liquid hydrocarbons. Experiments, especially with ATR 4, which produces a molar hydrogen stream equivalent to an electrical power in the fuel cell of 3 kW, showed that the process should be preferably run in the temperature range between 700 ° and 850 °. This ensures complete hydrocarbon conversion and avoids the formation of considerable amounts of methane and organic compounds in the product water. Experiments with commercial diesel showed promising results but insufficient long‐term stability. Experiments concerning the ignition of the catalytic reaction inside the reformer proved that within 60 s after the addition of water and hydrocarbons the reformer reached 95% of its maximum molar hydrogen flow. Measurements, with respect to reformer start‐up, showed that it takes approximately 7 min. to heat up the monolith to a temperature of 340 ° using an external heating device. Modelling is performed, aimed at the modification of the mixing chamber of ATR Type 5, which will help to amend the homogeneous blending of diesel fuel with air and water in the mixing chamber. 相似文献
16.
17.
18.
Diesel fuel desulfurization by different commercial activated carbons was studied in a batch adsorber. Experiments, carried out to determine the sulfur adsorption dependency on time, were used to perform kinetic characterization and to screen the best performing activated carbon. The equilibrium characterization of the adsorption process was also performed. The statistical study of the process was undertaken by way of a two‐level one‐half fractional factorial experimental design with five process parameters. Individual parameters and their interaction effects on sulfur adsorption were determined and a statistical model of the process was developed. Chemviron Carbon SOLCARBTM C3 was found to be the most efficient adsorbent. The kinetic pseudo‐second order model and Freundlich isotherm are shown to exhibit the best fits of experimental data. The lowest achieved sulfur concentration in treated diesel fuel was 9.1 mg kg–1. 相似文献
19.
Computational fluid dynamics (CFD) models based on the turbulent mixture multiphase model were applied to consider the effect of cavitation on the spray of diesel fuel. The effects of injection pressure and length‐to‐width (L/W) ratio on the velocity distribution, cavitation number, discharged coefficient, and nozzle exit velocity were investigated and the performance of the model was compared with the experimental data. The results indicate that the cavitation generated in the nozzle has a strong impact on the fuel injection and spray quality, whereas the L/W ratio is a highly effective parameter for cavitation behavior. In addition, by increasing the L/W ratio, the range of cavitation number, wall friction, and flow resistance increase but in the cavitation region the velocity profile in radial and axial directions, spray cone angle, nozzle exit velocity, and the discharged coefficient decrease. 相似文献
20.
A biodiesel storage stability study was conducted on Ultra Low Sulfur Diesel Fuel (ULSDF) and three biodiesel fuels (B100), including a Tallow-based Methyl Ester (TME), a Canola-based Methyl Ester (CME), and, a Yellow Grease Methyl Ester (YGME), and fuel blends (B5 and B20). The stability study was conducted over ten months (Aug 07-Jun 08) and consisted of storing fuel samples in quarter filled plastic and steel 20 L cans, in an unheated shed. Fuel cans were vented twice a week to ensure exposure of the fuel to air. Changes in Acid Number, kinematic viscosity and free water and sediments levels were monitored over the storage period. Temperature and relative humidity ranged from −25 °C to 35 °C and 25% to 100%, respectively. Acid Number and the viscosity did not increase beyond the uncertainty of the method used. Reference samples kept at 40 °C were used for comparison. Free water and sediment levels were barely above the detection limit of 0.003 mL/100 mL of fuel for CME and YGME and their blends. TME and its B20 blend displayed free water and sediment levels up to 0.05 mL/100 mL of fuel in February, after six months of storage. These values decreased considerably after the warm Summer months back to below 0.01 mL/100 mL. All free water and sediment levels were measured after fuel samples came to equilibrium with room temperature. The TME B5 free water and sediment levels remained low throughout the storage period. Proton Nuclear Magnetic Resonance (NMR) spectroscopy performed on particulates from the sediments revealed a similar composition but a slightly lower concentration for protons in alkenyl groups. The presence of these sediments was attributed to more saturated molecules coming out of solution in colder weather and very slowly going back to solution at room temperature. 相似文献