一种测量钢管长度的新方式

针对传统的采用接近开关或光电开关测量钢管长度方式存在的不足,开发出一种新型的测量方式,即采用间接测量方式检测钢管长度.新的钢管长度测量系统占地面积小,测量精度高,实际运行效果良好.     

Technoeconomic assessment of China’s indirect coal liquefaction projects with different CO2 capture alternatives

ICL (Indirect coal liquefaction), an alternative fuel-supplying technology, has drawn much attention and caused considerable debate in China’s energy sector. The hurdles to its development include the high risk of investment into large-scale installations, the high CO₂ emissions and water resource consumption. A comprehensive assessment of ICL is urgently needed. This study provides an economic assessment and a technical analysis based on process simulations. To address the future challenge of curbing CO₂ emissions, three absorption methods are compared for capturing the CO₂ released from the ICL process: DMC (a novel absorbent), MEA and Rectisol. The comparative results suggest that physical absorbents, represented by Rectisol and DMC, have a remarkable advantage over chemical absorption processes, represented by MEA. The Rectisol process costs the least, while the DMC process is close to the same level. As a novel absorbent, DMC has the potential to be widely used in the future. The economic analysis of ICL predicted a high capital cost of over 35 billion yuan and an overall product cost of approximately 3800 yuan/ton for the baseline. In addition, via a sensitivity analysis, coal price, electricity price and capacity factor were identified as the three most influential factors affecting the overall product cost.     

Novel twin reactor for separate evolution of hydrogen and oxygen in photocatalytic water splitting

Photocatalytic water splitting with separate H₂ and O₂ evolution is crucial because it eliminates the explosion potential and hydrogen-purification cost. A novel twin reactor was designed to separate the evolution of hydrogen and oxygen in photocatalytic water splitting under visible light. A modified Nafion membrane was employed to segregate the two photocatalysts in the twin reactor so that hydrogen and oxygen can be evolved separately. Conventional Z-scheme catalysts, Pt/SrTiO₃:Rh and WO₃, were used as hydrogen-photocatalyst and oxygen-photocatalyst, respectively. Fe²⁺ and Fe³⁺ were added in the reaction solution as electron-transfer mediator. The ratio of evolved H₂ and O₂ was in agreement with the stoichiometric ratio (2:1) of hydrogen and oxygen of water. An average hydrogen generation rate of 1.59 μmol/g-h was achieved in the twin-reactor system, which was twice as much as that in the conventional Z-scheme system. The improved H₂ yield was due to the prevention of the water-splitting backward reaction in the twin reactor.     

Theoretical and testing performance of an innovative indirect evaporative chiller

An indirect evaporative chiller is a device used to produce chilled water at a temperature between the wet bulb temperature and dew point of the outdoor air, which can be used in building HVAC systems. This article presents a theoretical analysis and practical performance of an innovative indirect evaporative chiller. First, the process of the indirect evaporative chiller is introduced; then, the matching characteristics of the process are presented and analyzed. It can be shown that the process that produces cold water by using dry air is a nearly-reversible process, so the ideal produced chilled water temperature of the indirect evaporative chiller can be set close to the dew point temperature of the chiller’s inlet air. After the indirect evaporative chiller was designed, simulations were done to analyze the output water temperature, the cooling efficiency relative to the inlet dew point temperature, and the COP that the chiller can performance. The first installation of the indirect evaporative chiller of this kind has been run for 5 years in a building in the city of Shihezi. The tested output water temperature of the chiller is around 14–20 °C, which is just in between of the outdoor wet bulb temperature and dew point. The tested COP_r,s of the developed indirect evaporative chiller reaches 9.1. Compared with ordinary air conditioning systems, the indirect evaporative chiller can save more than 40% in energy consumption due to the fact that the only energy consumed is from pumps and fans. An added bonus is that the indirect evaporative chiller uses no CFCs that pollute to the aerosphere. The tested internal parameters, such as the water–air flow rate ratio and heat transfer area for each heat transfer process inside the chiller, were analyzed and compared with designed values. The tested indoor air conditions, with a room temperature of 23–27 °C and relative humidity of 50–70%, proved that the developed practical indirect evaporative chiller successfully satisfy the indoor air conditioning load for the demo building. The indirect evaporative chiller has a potentially wide application in dry regions, especially for large scale commercial buildings. Finally, this paper presented the geographic regions suitable for the technology worldwide.     

巴西油气合同模式与财税政策新动向

巴西Lula油田的发现证实了桑托斯盆地世界瞩目的勘探潜力,巴西政府调整油气战略,针对盐下地区的核心资源推出了产品分成合同。随着2015年以来巴西经济衰退与腐败丑闻的冲击,巴西政府为吸引国际投资,在财税政策上做出了部分让步,废除了巴西国家石油公司在盐下地区强制作业者权力和至少30%权益的保障、延长了"REPETRO"免税机制20年、大幅降低了本地化采购比例的要求,促进了2017年深水勘探区块的招投标。通过合同模式的对比发现,政府能够在产品分成合同获取更高的分成比例,加强了盐下核心资源的控制。通过对本地化采购要求和间接税体制的解剖,深入认识到采购策略、本地化采购要求和间接税纳税筹划三者之间紧密相连,为中国油公司在巴西油气项目的招投标、并购和运作提出了合适的建议。     

矿山回风井风量的间接测定装置设计研究

设计研究了一种适合于矿山回风井风量间接测定装置,该装置是由感压与导压组件、测压组件或通风在线监测系统构成。感压与导压组件包括外环、中间环、内环,外环的内侧侧面设有感静压孔,中间环、内环的底部设有感全压孔;测压组件由带刻度的静压U型管、全压U型管、静压压力传感器、全压压力传感器、静压三通、全压三通构成。风流压力经导压软管与U型管及压力传感器连接以测定全压与静压,再根据公式计算出回风井风量。装置具有结构简单、操作方便实用、测定安全可靠、测量数据准确、风量计算简单等优点。     

Thermo-economic optimization of an indirectly coupled solid oxide fuel cell/gas turbine hybrid power plant

Power generation using gas turbine (GT) power plants operating on the Brayton cycle suffers from low efficiencies, resulting in poor fuel to power conversion. A solid oxide fuel cell (SOFC) is proposed for integration into a 10-MW GT power plant, operating at 30% efficiency, in order to improve system efficiencies and economics. The SOFC system is indirectly coupled to the GT, in order to minimize the disruption to the GT operation. A thermo-economic model is developed to simulate the hybrid power plant and to optimize its performance using the method of Lagrange Multipliers. It predicts an optimized power output of 18.9 MW at 48.5% efficiency, and a breakeven per-unit energy cost of USD 4.54 ¢ kW h⁻¹ for the hybrid system based on futuristic mass generation SOFC costs.     

Effect of Cu/Zn on microstructure and mechanical properties of extruded Mg–Sn alloys

In this paper, the effect of Cu and Zn addition on mechanical properties of indirectly extruded Mg–2Sn alloy was investigated. Mg–2Sn–0.5Cu alloy exhibits a moderate yield strength (YS) of 225?MPa and an ultimate strength of 260?MPa, which are much higher than those of the binary Mg–2Sn alloy, and the elongation (EL) evolves as ～15.5%. Mechanical properties of the Mg–2Sn–0.5Cu alloy are deteriorated with more 3 wt-% Zn addition, and YS and EL are reduced as 160?MPa and ～10%. The detailed mechanism is discussed according to the work-hardening rate and strengthening effect related to the grain sizes, second phases and macro-textures. Grain refinement and proper texture are believed to play a critical role in both strength and ductility optimisation.     

Enhanced hydrogen generation from methanol aqueous solutions over Pt/MoO3/TiO2 under ultraviolet light

The photocatalytic activity in hydrogen production from methanol reforming can be significantly enhanced by Pt/MoO₃/TiO₂ photocatalysts. Compared with Pt/P25, the photocatalytic activity of optimized Pt/MoO₃/TiO₂ shows an evolution rate of 169 μmol/h/g of hydrogen, which is almost two times higher than that of Pt/P25. XRD and Raman spectra show that MoO₃ are formed on the surface of TiO₂. It is found that with the bulk MoO₃ just formed, the catalyst shows the highest activity due to a large amount of heterojunctions and the high crystallinity of MoO₃. The HRTEM image showed a close contact between MoO₃ and TiO₂. It is proposed that the Z-scheme type of heterojunction between MoO₃ and TiO₂ is responsible for the improved photocatalytic activity. The heterojunction structure of MoO₃/TiO₂ does not only promote the charge separation, but also separates the reaction sites, where the oxidation (mainly on MoO₃) and reduction (on TiO₂) reactions occurred.     

半导体光催化全分解水的最新研究进展

从半导体光催化剂全分解水反应原理出发,介绍了近年来新开发的无机半导体光催化剂,如钽酸盐半导体,Ge基半导体、Ga基半导体,层状金属氧化物,具有d0、d10电子构型的半导体和Z型反应体系,分析了光催化效率的影响因素,并对未来做出了展望。