PS,LS和煤油体系的界面张力

本文以石油磺酸盐(PS)、木质素磺酸盐(LS)和煤油体系为对象,研究了PS/LS比、盐度、醇、Na_2SiO_3及聚合物对体系界面张力(IFT)的影响,探讨了PS与各组分间的相互作用,结果发现,在一定盐度和混合醇(正丁醇+异丙醇)浓度下,PS/LS>0.3/0.7时,体系可形成中相微乳液,IFT值达1×10~(-3)mN/m左右;LS和聚合物的存在使IFT升高;在表面活性剂驱油体系中,可用廉价的LS部分代替PS。     

Application of the Box-Wilson experimental design method for the spherical oil agglomeration of coal

In this study, the Box-Wilson statistical experimental design method was employed to evaluate the effects of important variables such as bridging liquid (oil) concentration, salt (CaCl₂·2H₂O) concentration and stirring speed on the agglomeration of bituminous coal. Response function coefficients were determined by the regression analysis of experimental data and the predictions were found to be in good agreement with the experimental results. The optimum kerosene concentration, CaCl₂·2H₂O concentration and stirring speed were determined as 30 wt%, 1 M and 1683 rpm, respectively, when considering combustible recovery and ash content.In addition, contact angle and solution surface tension measurements were carried out to evaluate of agglomeration success with the contact angle values and surface tension values. The surface tension of CaCl₂ 2H₂O solutions and the average contact angle increased with increasing CaCl₂·2H₂O concentration.     

Small-scale portable photovoltaic-battery-LED systems with submersible LED units to replace kerosene-based artisanal fishing lamps for Sub-Saharan African lakes

A technical simulation and economic model was developed for a floating photovoltaic (PV)-battery system powering a submerged light emitting diode (LED) lighting system. The system was designed to provide around the equivalent of 1000 lumens (lm) of light of the existing light fishing technology (a floating pressurised kerosene light) for artisanal light fishers to use for 8 h per night on Lake Victoria and other lakes in the region (Tanganyika, Rukwa, Mweru, Kivu, etc.). The net present cost (NPC) of a technically appropriate PV-battery-LED system was calculated as US$280 over 5 years, five-times less than the existing solar-based technology, a PV-battery-compact fluorescent lamp (CFL) system, and around ten times less than the baseline pressurised kerosene-based technology over the five years. Fishers owning the new PV-battery-LED system outright will likely recoup their initial investment within a year relative to the cost of alternatives, although the upfront capital cost of the new system was higher than the pressurised kerosene and PV-battery-CFL, and found to be practically unaffordable to the subsistence fishers without microcredit. Nonetheless, the technical simulations found that the new system was also able to provide additional lighting services during the day and evening, with little (if any) electrical impact on the system when in use for light fishing during the small hours of moonless nights. This research also demonstrates that the high cost of operating pressurised kerosene lamps precludes them for use in other applications within the community, including in homes. This research suggests that facilitated local development of appropriate new light fishing technology configurations will require training of local individuals to sensitise fishing communities to the new technology, and sustain wider adoption of the more efficient, cost-effective, and safer alternative.     

γ辐照后TBP—煤油对^95Zr的萃取和保留

研究了用不同浓度HNO_3预平衡和经γ辐照不同剂量后的TBP-煤油对~(95)Zr的萃取行为。测定了0.01mol/1HNO_3,5%Na_2CO_3洗涤后的有机相中~(95)Zr的保留百分率。比较了辐照后的TBP-煤油用碱和水萃洗分离得到的三个组份以及HDBP等7种辐解产物对~(95)Zr的萃取和洗涤后有机相中的保留情况。结果表明~(95)Zr的萃取和洗涤后的保留与溶剂所受的辐照剂量和预平衡酸度均有关系。在辐解产物中,单烷基长链酸性磷酸酯和异羟肟酸对Zr的萃取影响都较严重。前者在碱洗时容易产生乳化,而后者在碱洗后对Zr的保留更为严重。     

机械密封技术在煤油泵方面的应用现状与分析

煤油泵是航天设备中的重要部件,而机械密封技术又是保证煤油泵正常可靠工作的关键技术,综述了机械密封技术在以煤油泵为代表的低粘度介质液压泵领域的发展状况。首先,介绍了机械密封技术的基本原理;随后,分别从国外和国内两个角度论述了煤油泵中采用的机械密封方法和主要产品;然后,针对煤油泵的特殊工况总结了相对应的机械密封的关键技术;最后,对机械密封技术在煤油泵领域的应用进行了分析和总结。     

Nickel-catalyzed autothermal reforming of jet fuel surrogates: n-Dodecane,tetralin, and their mixture

The potential of a nickel-ceria-zirconia based catalyst was examined for autothermal reforming of n-dodecane, tetralin and their mixture into a hydrogen-rich product stream suitable for high-temperature fuel cells. n-Dodecane and tetralin were chosen as representative compounds for alkanes and bicyclic compounds in jet fuel. It was possible to reach conversions greater than 90% for both components, as long as sufficiently high oxygen concentrations were maintained in the feed. Tetralin gave larger yields of reforming products than n-dodecane. During the transient start-up phase of the reactor, large temperature excursions were observed, suggesting that the reaction starts with complete combustion of fuel, giving way to autothermal reforming after a few minutes on stream. These high-temperature excursions during reactor start-up are large enough to change the catalyst surface areas. Interestingly, the mixture of tetralin and n-dodecane did not behave as a linear combination of the two pure components, but showed reforming characteristics similar to pure tetralin. The non-linear behavior of the mixture provides a caveat that investigations of single component model compounds may not be able to capture the reforming behavior of more complex fuel mixtures.     

分光光度法测定汽、煤、柴油中的硫含量

提出的汽、煤、柴油中硫含量的分光光度测定法,可作为国标化学分析法的代替方法。本法的检出限量为0.01mg,样品用量少,灵敏,快速,选择性好,易于操作。     

Effects of polymer modification on the fuel resistance of asphalt binders

Fuel resistance is an important characteristic of asphalt binders, especially when used in airport fields and filling stations. However, the relevant standards are presently lacking and the scientific literature on the development of suited formulations is sparse. In this paper, a simple procedure to assess the fuel resistance of asphalts (considered in a dynamic sense) is proposed. A number of polymer modified asphalts (PMAs), prepared from two bases and 4 or 6 wt% of several polymers, have been analyzed with this procedure and the relationships between fuel resistance and morphology of the PMAs, the chemical structure of the polymers and the composition of the asphalt bases have been investigated.     

Emissions and wall temperatures for lean prevaporized premixed gas turbine combustor

Experimental studies are carried out for investigating emission and wall temperature for traditional gas turbine combustor converted to lean premixed prevaporized (LPP) combustor. Vortex chamber, air preheating system, flat flame burner and inlet temperature control system are designed. Vortex chamber was maintained at the main air inlet port for controlling secondary air flow rate and wall temperature. Kerosene/air mixture temperature at exit from burner and entering combustion chamber was kept constant at 650 K for all runs. Special considerations were given for measuring NO_X, UHC, CO, local A/F ratio, flame temperature, exhaust gases temperature and wall temperature. For swirl and non swirl cases, secondary air ratio and primary zone air/fuel ratio were varied. The different operating parameters affecting flame temperature through it is affecting on local A/F ratio which is the main parameter for controlling flame temperature, emissions and walls temperatures. Flat flame burner and vortex chamber are useful tools for reducing emission and controlling walls temperatures. The inner liner wall temperatures are more affected by primary zone equivalence ratio while the outer liner wall temperatures are more affected by secondary air flow rate. Semi empirical correlations for NO_X, UHC and CO concentrations, exhaust gases temperature and maximum inner liner wall temperature are carried out. Good agreement between the measured and the calculated results are obtained. The present results are useful for further development of the traditional gas turbine combustor converted to LPP combustor.