含油水处理用动态水力旋流器溢流结构设计研究

从改进动态水力旋流器主要构件中溢流嘴的结构形状及参数入手 ,利用工程数学、流体动力学及三维CAD造型技术等相关知识 ,对其进行了结构优选设计与对比分析。这为提高其设计精度、制造分离性能更为优良的样机及其在含油水处理方面的实际应用提供一定的指导     

关于 HCSC6 型环锤式碎煤机调节间隙的计算及应用

论述ＨＣＳＣ６型环锤式碎煤机筛板间隙的调节原理和理论计算方法,并使之运用于实际,使碎煤机筛板间隙的调节快速、准确,为环锤式碎煤机在理想工况下运行创造必要的条件。     

The storage performance of automotive cryo-compressed hydrogen vessels

Cryo-compressed hydrogen storage promises to deliver the highest system storage density leading to practical vehicles with range comparable to today's gasoline vehicles and fundamental cost and safety advantages. However, cryogenic vessels are complex systems, continuously drifting in thermodynamic space depending on use patterns, insulation performance, vessel characteristics, liquid hydrogen pump performance, and para-H₂ to ortho-H₂ conversion. In this paper, cryogenic vessel fill density results from a previous publication are extended to calculate system storage performance, including volumetric (gH₂/L), gravimetric (H₂ weight fraction), and vent losses over a broad range of conditions. The results confirm previous experiments and models indicating that cryogenic pressure vessels have maximum system density of all available storage technologies while avoiding vent losses in all but the most extreme situations. Design pressures in the range 250–350 bar seem most advantageous due to high system density and low weight and cost, although determining an optimum pressure demands a complete economic and functional analysis. Future insulation, vessel, and liquid hydrogen pump improvements are finally analyzed that, while not experimentally demonstrated to date, show promise of being feasible in the future as their level of technical maturity increases, leading to maximum H₂ storage performance for cryo-compressed storage. If proven feasible and incorporated into future cryogenic vessels, these improvements will enable 50 + gH₂/L system density at 10+% H₂ weight fraction.     

Maximum overpressure vs. H2 concentration non-monotonic behavior in vented deflagration. Experimental results

Explosion relief panels or doors are often used in industrial buildings to reduce damages caused by gas explosions. Decades of research have contributed to the understanding of the phenomena involved in gas explosions in order to establish an effective method to predict reliably the explosion overpressure. All the methods predict a monotonic increase of the overpressure with the concentration of the gas in the range from the lower explosion limit to the stoichiometric one. Nevertheless, in few cases, a non-monotonic behaviour of the maximum developed pressure as a function of hydrogen concentration was reported in the literature. The non-monotonic behaviour was also observed during experimental tests performed at the Scalbatraio laboratory at the University of Pisa, in a 25 m³ vented combustion test facility, with a vent area of 1,12 m². This paper presents the results obtained during the tests and investigates the possible explanations of the phenomena.     

Thermal explosion hazards on 18650 lithium ion batteries with a VSP2 adiabatic calorimeter

Thermal abuse behaviors relating to adiabatic runaway reactions in commercial 18650 lithium ion batteries (LiCoO₂) are being studied in an adiabatic calorimeter, vent sizing package 2 (VSP2). We select four worldwide battery producers, Sony, Sanyo, Samsung and LG, and tested their Li-ion batteries, which have LiCoO₂ cathodes, to determine their thermal instabilities and adiabatic runaway features. The charged (4.2 V) and uncharged (3.7 V) 18650 Li-ion batteries are tested using a VSP2 with a customized stainless steel test can to evaluate their thermal hazard characteristics, such as the initial exothermic temperature (T₀), the self-heating rate (dT/dt), the pressure rise rate (dP/dt), the pressure-temperature profiles and the maximum temperature (T_max) and pressure (P_max). The T_max and P_max of the charged Li-ion battery during the runaway reaction reach 903.0 °C and 1565.9 psig (pound-force per square inch gauge), respectively. This result leads to a thermal explosion, and the heat of reaction is 26.2 kJ. The thermokinetic parameters of the reaction of LiCoO₂ batteries are also determined using the Arrhenius model. The thermal reaction mechanism of the Li-ion battery (pack) proved to be an important safety concern for energy storage. Additionally, use of the VSP2 to classify the self-reactive ratings of the various Li-ion batteries demonstrates a new application of the adiabatic calorimetric methodology.