宝泉电站水泵水轮——发电电动机组的安装

宝泉抽水蓄能机组安装特点是:设备设计采用了裙翼式转子、超高铁心定子、可逆式单级转轮、支柱式带微米位移传感器的抗重螺栓推力轴承等抽水蓄能新技术,结构新颖轻巧、安装工艺独特、新技术应用较多,而施工工期紧迫,要求施工流程安排紧凑。宝泉抽水蓄能机组的组装和安装程序及特点,可供参考。     

复合材料在坦克装甲防护中的应用

坦克装甲防护事材料是主战坦克防护系统的重要组成部分,本文介绍了几种目前用于主战坦克装甲防护用聚全物基复合材料,着重阐述了基吸应用现状产指出未来的坦克装甲防护系统中复合材料的应用趋势。     

Storage as a tool to improve wood fuel quality

This work analysed the influence of storage in the quality of forest biomass for energy generation in the region of Lages, Brazil. Logs of Pinus taeda L. and Eucalyptus dunnii Maiden were harvested and piled during the four different seasons: spring, summer, fall and winter. The analyses were performed immediately after harvesting (without being stored), after two, four and six months of storage. The evaluated properties were: moisture content, gross and net calorific value, ash content and solubility in cold water, hot water and sodium hydroxide. The species composition, storage span, harvesting season and storage season influenced the forest biomass characteristics. In general, eucalyptus presented better results than pine, losing moisture faster, having less alteration in the chemical composition and producing greater energetic gain over storage time. For both species, the ideal storage time was four months. Furthermore, spring and summer were the best harvesting seasons. Thus, if the forest biomass is harvested at the end of winter or beginning of spring with subsequent storage during the summer, this biomass will have the best performance for energy production.     

Integral approximate solution for the charging process in stratified thermal storage tanks

This paper presents the approximate integral solutions to the one-dimensional model describing the charging process of stratified thermal storage tanks with fluid mixing at the inlet. The temperature is assumed to be a form of the Fermi–Dirac distribution function, which can be separated into two sets of cubic polynomials for the hot and cold sides of the thermal boundary layers. The proposed approximate integral solutions are compared with previous works on approximate analytic solutions and show reasonable agreement. This approach, however, benefits from reduced mathematical complexity as compared with the complicated solution form and unstable convergence of the series solution found in the previous analytic solutions. For the ideal case of no fluid mixing at the inlet, the thermocline thickness is proportional to the square root of time and reversely proportional to the flow rate. However, if the fluid is mixed perfectly in the region near inlet, the thermocline thickness could be thicker as the flow rate increases because of the increased mixing region caused by promoted flow mixing in this region. Thus the optimal flow rate depends on the relationship between the flow rate and the size of the mixing region.     

Carbon capture and storage—Investment strategies for the future?

The following article deals with real options modeling for investing into carbon capture and storage technologies. Herein, we derive two separate models. The first model incorporates a constant convenience yield and dividend for the investment project. In the second model, the convenience yield is allowed to follow a mean reverting process which seems to be more realistic, but also increases the model’s complexity. Both frameworks are to be solved numerically. Therefore, we calibrate our model with respect to empirical data and provide insights into the models’ sensitivity toward the chosen parameter values. We found that given the recently observable prices for carbon dioxide, an investment into C O2-storage facilities is not profitable.     

Perceptions of opinion leaders towards CCS demonstration projects in China

We present results of a major survey of Chinese opinion leaders conducted from March to April 2009, supported by EU–UK–China near zero emissions coal (NZEC) initiative. Respondents were drawn from 27 provinces and regions using an online survey with follow-up face-to-face interviews. A total of 131 experts and decision-makers from 68 key institutions were consulted through online survey. This survey is the first to focus on demonstration projects in particular and is the most geographically diverse. We aim to understand perceptions of applying CCS technologies in the first large-scale CCS demonstration project in China. Though enhanced oil recovery (EOR) and enhanced coal bed methane recovery (ECBM) may not be long-term solutions for CO₂ storage, they were viewed as the most attractive storage technologies for the first CCS demonstration project. With regard to CO₂ capture technology, on the whole, post-combustion (which would be most applicable to the vast majority of existing power plants which are pulverised-coal) received slightly higher support than pre-combustion. More surprising, respondents from both the power and oil industries favoured pre-combustion. There was no consensus regarding the appropriate scale for the first demonstration. A large number of respondents were concerned about the energy penalty associated with CCS and its impact on the long-term sustainability of coal supply in China, although such concerns were much reduced compared with surveys in 2006 and 2008.     

Comparative analysis of the hydriding kinetics of LaNi5, La0.8Nd0.2Ni5 and La0.7Ce0.3Ni5 compounds

In two-phase domains, the plateau pressure of hydride forming materials (such as intermetallic compounds or IMCs) depends markedly on the operating temperature (Van’t Hoff relationships). Therefore, for practical applications, it is necessary to select hydrogen storage materials by considering the thermal environment of the hydride tank. The thermodynamic properties (absorption and desorption pressure plateaux) of IMCs can be adjusted to some extend by chemical alloying with foreign metals and substitution on different crystallographic sites. In this paper, we report on the hydriding kinetics of substituted AB₅ compounds. Isotherms have been measured at different temperatures on La_xNd_1−xNi₅ (x ≈ 0.2) and La_xCe_1−xNi₅ (x ≈ 0.3) compounds. Pneumato-chemical impedance spectroscopy has been used to analyze the hydriding kinetics and to determine microscopic rate parameters associated with surface dissociation of molecular hydrogen, diffusion-controlled transport of atomic hydrogen to bulk regions and hydride formation. Results have been compared to those measured on LaNi₅ and the interest of using such substituted compounds for application in auxiliary power units is discussed.     

Storage stability and ageing effect of biodiesel blends treated with different antioxidants

This study investigates the impact of various synthetic phenolic antioxidants on the oxidation stability of biodiesel blends with the employment of the modified Rancimat method. The experimental results revealed that an improvement in oxidation stability could be achieved with all antioxidants tested. Butylated hydroxytoluene (BHT) and butylated hydroxyanisol (BHA) displayed the lowest effectiveness in neat biodiesel, whereas their use in biodiesel blends showed a greater stabilizing potential. Propyl gallate (PG) and pyrogallol (PA) additives showed the strongest effectiveness in both the neat biodiesel and the biodiesel blends. During a naturally ageing process of the biodiesel blends which was conducted for a period of 10 weeks, samples were taken every 2 weeks to measure the oxidation stability, kinematic viscosity and acid value. This process was designed in such manner to simulate the ageing of an automotive biofuel stored in the fuel tank of a vehicle. The results showed a sharp decrease in fuel stability over time. Although limited effects were observed in viscosity, the acid value was significantly increased over time. The addition of antioxidants resulted in some increases in viscosity and acid value of the biodiesel blends.     

内转塔式FPSO单点建造脚手架难点分析

基于对内转塔式浮式生产储卸油装置（Floating Production Storage and Offloading,FPSO）单点建造的工艺分析,在结构三维模型中,结合不同模块构造,建立不同施工阶段的脚手架模型,分析各脚手架的设计参数及难点。分析结果可为内转塔式单点建造脚手架施工提供参考,也可为同类型的项目建造提供借鉴。     

A computational fluid dynamic study of the filling of a gaseous hydrogen tank under two contrasted scenarios

The filling of a horizontal hydrogen tank designed for light duty vehicles is investigated by means of multi-physics numerical simulations. The simulation approach, implemented in OpenFOAM, includes compressible Reynolds-Averaged Navier-Stokes (RANS) modeling of the fluid flow and heat transfer in the solid parts. The simulations are carried out for 2D-axisymmetric and 3D configurations. Two filling scenarios of the tank, leading to two distinct thermal behaviors, i.e. homogeneous versus heterogeneous, are simulated and compared to the experimental data issued from the HyTransfer project. In the homogeneous case, where no thermal stratification occurs, the 2D and 3D simulation results are close to the experimental ones. A phenomenon of jet flapping is identified via the 3D simulation. In the heterogeneous case, where thermal stratification occurs, the 3D simulation captures an averaged temperature close to the experimental one, as well as the instant at which the thermal gradients appear. It also captures the deflection of the jet, which is a central element in the emergence of the thermal gradients.