氢浆制备特性及其潜在应用

概述氢浆的制备特性及其在空间技术中用作推进剂的可能性     

The convection heat transfer coefficient in a Circulating Fluidized Bed (CFB)

Circulating Fluidized Beds are increasingly used in gas–solid and gas–catalytic reactions. A recent development involves their use in physical gas–solid processes such as drying, VOC adsorption or solar energy capture and storage. The heat transfer from the wall of the CFB to the flowing gas–solid suspension is the major design parameter, and was studied for different powders at different operating conditions as determined by the gas velocity and solids circulation flux. Measured values of the heat transfer coefficients are discussed, and compared with empirical predictions of Molodtsof–Muzyka, and Gorliz–Grace. Whereas Gorliz–Grace predicts heat transfer coefficients correctly within a narrow range of operating conditions only, the Molodtsof–Muzyka approach can be simplified into a linear relationship.     

Statistics of Capillary Waves on the Surface of Liquid Hydrogen in a Turbulent Regime

Excitation of the surface of liquid hydrogen by a harmonic force at low frequencies leads to the formation of turbulent cascade in the system of capillary waves. We have found that the probability density function for a high-frequency surface deviation from equilibrium state in the regime of developed turbulence is well approximated by the Gaussian distribution.      

液氧回灌阀燃爆事故分析及预防

介绍一起因液氧回灌阀反向使用造成阀门爆裂、导致空分设备停车的事故,分析了造成事故的原因及采取的防范措施。     

一起氧气管道低温态爆破事故

介绍一起氧气管道低温态超压爆破事故,分析了原因,并提出防范措施。     

液氧回灌阀燃爆事故分析及预防

介绍一起因液氧回灌阀反向使用造成阀门爆裂、导致空分设备停车的事故，分析了造成事故的原因及采取的防范措施。     

液氧泵回流阀爆裂事故原因分析

介绍一起液氧内压缩流程中液氧泵回流阀爆裂事故的经过和破坏情况,初步认为事故的原因可能是阀门制造缺陷导致升压过程中上阀体破裂后高压液氧泄漏,进而引发化学性爆炸。最后提出了防止液氧泵回流阀燃爆的预防措施。     

一起氧气管道低温态爆破事故

介绍一起氧气管道低温态超压爆破事故，分析了原因，并提出防范措施。     

Development of density and mass flow rate measurement technologies for slush hydrogen

Slush hydrogen is a two-phase solid-liquid cryogenic fluid consisting of solid hydrogen particles in liquid hydrogen. Compared to liquid hydrogen, the density is about 16% greater at a solid mass ratio (solid fraction) of 50%, and the cryogenic heat capacity (enthalpy) is about 18% higher. Various applications are anticipated, including fuel for reusable space shuttles, coolant for cold neutron generation, as well as the transport and storage of hydrogen as a clean energy source. At a solid fraction of within 50%, piped transport can be conducted in the same way as for normal fluids. This paper reports on the slush hydrogen technology in terms of the measurement of the density and the mass flow rate.     

液氧贮槽爆炸事故树分析

采用安全系统工程的方法 ,对液氧贮槽爆炸进行了事故树分析 ,通过求事故树最小割集 ,进行结构重要度分析 ,从而对液氧贮槽爆炸的事故原因进行分析、预测 ,并提出了相应的预防控制措施     

爆炸复合材料中金属的强化

用大量的强度性能数据讨论了爆炸复合材料中金属的强化问题。指出 ,这种强化是明显的 ,表现在复合材料总体强度的提高和基材各自强度的提高两个方面 ;这种强化的程度与爆炸焊接工艺参数和基材本身的强化趋势有关 ;这种强化的合理利用、减轻和消除的方法 ,以及引起强化的原因和规律的探讨 ,是爆炸焊接应用和理论研究的重要课题     

溜冰场制冷负荷的分析计算及设备选型探讨

本文介绍了溜冰场在不同情况下的制冷负荷分析计算,得出滑冰场的负荷估算指标并对设备的选型进行探讨.     

LNG容器蒸气膨胀爆炸特性研究

对液化天然气容器机械破损后的液体过热汽化建立了非平衡相变模型.根据非平衡相变理论,讨论了蒸气膨胀爆炸的过减压极限,并按照气泡半径是否超过临界半径,把气泡的增长分成了束缚和逃逸两个时区,分时区讨论了系统各物理量的变化.通过对液化天然气典型储运工况的计算,得出了不同条件下的过减压极限、压力下降及反弹演化过程,状态参量核化速率的变化过程及最大超压.分析了蒸气膨胀爆炸的基本特性:快速显著核化和沸腾延迟,以及初始条件、损口面积和容器尺度等对物理过程的影响.     

Capillary cooling of superconducting coils with two-phase hydrogen or nitrogen

Superconducting coils in AC application, such as in the stator of superconducting motors, have losses which warm up the coil and so limit the performance. Good thermal contact between the coil and the cooling agent is important. In this research we investigate the possibility of cooling the coils by a cryoliquid, such as liquid hydrogen or liquid nitrogen, flowing through capillaries in thermal contact with the coils.     

可燃气云抑爆技术初探

试验表明,在可燃气云爆炸引发过程或爆炸初始阶段,通过喷洒抑爆材料可抑制爆炸燃烧反应进程,继而中断爆炸反应或显著削弱爆炸强度.无机粉末、惰气和水雾是性价比较高的抑爆材料,具有大面积推广的价值.探讨了可燃气云的抑爆机理,并指出可燃气云抑爆技术后续研究中亟待解决的问题,为可燃气云抑爆技术的实际应用提供了技术参考.     

Explosion characteristics of synthesised biogas at various temperatures

Biogas is considered as a valuable source of renewable energy. Indeed, it can be turned into useful energy (heat, electricity, fuel) and can contribute to reduce greenhouse gas emissions. Knowledge of its safety characteristics is a very important practical issue. Experimental investigation of synthesised biogas explosion characteristics was conducted in a 20-L sphere at various temperatures (30-70 degrees C) and at atmospheric pressure. The studied biogas was made of 50% methane (CH(4)) and 50% carbon dioxide (CO(2)). It was also saturated with humidity: this composition is frequently met in digesters during waste methanisation. There are two inert gases in biogas: water vapour and carbon dioxide. Its vapour water content rises along with temperature. The presence of these inert gases modifies considerably biogas characteristics compared to the ones of pure methane: explosion limits are lowered and beyond 70 degrees C, water vapour content is sufficient to inert the mixture. Furthermore, explosion violence (estimated with the maximum rate of pressure rise values, (dp/dt)(max)) is three times lower for biogas than for pure methane at ambient temperature.