动力外置式热室起重机

对于小型处理强放射性物质的独立屏蔽热室,由于无法设置起重机检修间,且人员无法进入热室内对热室内维修起重机,故无法采用常规起重机方案进行物料转运。该类起重机需考虑热室内部件的免维护设计,将对放射性较为敏感的电气驱动部件设置在热室外,文中阐述了对驱动外置热室起重机的设计要点,从整体布局、传动系统、传动贯穿件、起升机构等方面进行了分析,并阐述了耦合长传动链传动技术以及高精度定位技术等驱动外置起重机的关键技术,为后续该类型起重机的设计研发提供参考思路。

桥式起重机主梁下挠的处理

主要阐述桥式起重机下产生的原因，后果及所采取的处理措施，并着重叙述了采用预应力矫正法处理桥式起重机下挠的原因及结果。

Theoretical Study on Vibrational Spectra, Detonation Properties and Pyrolysis Mechanism for Cyclic 2-Diazo-4,6-dinitrophenol

Based on the full optimized molecular geometrical structures at the DFT-B3LYP/6- 311＋G^＊＊ level, there exists intramolecular hydrogen bond interaction for cyclic 2-diazo- 4,6-dinitrophenol. The assigned infrared spectrum is obtained and used to compute the thermodynamic properties. The results show that there are four main characteristic regions in the calculated IR spectra of the title compound. The detonation velocities and pressures are also evaluated by using Kamlet-Jacobs equations based on the calculated density and condensed phase heat of formation. Thermal stability and the pyrolysis mechanism of 2- diazo-4,6-dinitrophenol are investigated by calculating the bond dissociation energies at the B3LYP/6-311＋G^＊＊ level.

Coupled thermo-hydro-mechanical-migratory model for dual-porosity medium and numerical analysis

A coupled thermo-hydro-mechanical-migratory model of dual-porosity medium for saturated-unsaturated ubiquitous-joint rockmass was established,in which the stress field and the temperature field were single,but the seepage field and the concentration field were double,and the influences of sets,spaces,angles,continuity ratios,stiffnesses of fractures on the constitutive relationship of the medium were considered.Also,the relative two-dimensional program of finite element method was developed.Taking a hypothetical nuclear waste repository as a calculation example,the case in which the rockmass was unsaturated dual-porosity medium and radioactive nuclide leak was simulated numerically,and the temperatures,negative pore pressures,saturations,flow velocities,nuclide concentrations and principal stresses in the rockmass were investigated.The results show that the negative pore pressures and nuclide concentrations in the porosity and fracture present different changes and distributions.Even though the saturation degree in porosity is only about 1/10 that in fracture,the flow velocity of underground water in fracture is about three times that in porosity because the permeability coefficient of fracture is almost four orders higher than that of porosity.The value of nuclide concentration in fracture is close to that in porosity.

Development of a Research Probe for Geothermal Boreholes

This paper introduces the idea of a framework for the implementation of novel downhole probes. A couple of examples （e.g. a tracer detector, a casing smear test probe or a casing repair probe） demonstrate that many components can be reused. These are the ＂bricks＂ of the ZWERG toolkit which is developed to match the environment in boreholes. Two ＂bricks＂ are described in detail： The housing （1） has to resist the pressure and other mechanical stress in deep holes. The selection of the material and the calculation of the wall thickness are the main interests. In many applications, a thermal management （2） of the inside of the probe is absolutely necessary. A dewar vessel can uncouple the heat of the geothermal reservoir and the temperature in the probe. It is important to understand the physical heat flow mechanisms. A set of formulas allows a good estimation of the quantity of heat that warms up the probe. The toolkit contains some immaterial ＂bricks＂ like blueprints of proven designs or support for the logistic process of finding and purchasing compatible components. The intention to drill near magma chambers calls for a common eflbrt of the geothermal community to gather compatible components, assemblies and knowhow and makes it widely available. ZWERG could be a starting point.

Condensation heat transfer enhancement mechanism for vertical upflows by the phase separation concept at small gravity

In the field of aerospace, minimum and seal of equipments cause the increase in the thermal loading sharply. Due to the lack of driving force, the performance of conventional condenser deteriorates greatly under the small gravity environment, which leads to reduction in the service life of equipments. In this study, a passive condenser, developed on basis of the phase separation concept,is utilized to improve the performance of the condensation heat transfer under the small gravity environment. As a result of the limitation of experiments, the mechanisms of heat transfer enhancement of the phase separation condenser tube are revealed through numerical simulation based on the volume-of-fluid(VOF) method. The following conclusions could be obtained:(1) A novel phase distribution of ‘‘gas near the tube wall and liquid in the tube core'' is formed. The thin liquid film is indeed created after the flow pattern modulation by inserting mesh cylinder.(2)The condensation quantity for single bubble in the annular region increases about 16 times greater than that in the bare tube region in the case of Jl= 0.0574 m/s and Jg= 0.0229 m/s.(3) Gas volume fraction affects the parameters of liquid film thickness, bubble length and liquid bridge length. The increase in the gas volume fraction results in the decrease in the evaluation index from21.56 to 12.82. The evaluation index is defined as the ratio of the condensation quantities per unit tube length of the annular region and the bare tube region.

Overall optimization of Rankine cycle system for waste heat recovery of heavy-duty vehicle diesel engines considering the cooling power consumption

The Rankine cycle system for waste heat recovery of heavy-duty vehicle diesel engines has been regarded as a promising tech- nique to reduce fuel consumption. Its heat dissipation in the condensation process, however, should be take：l away in time, which is an energy-consuming process. A fan-assisted auxiliary water-cooling system is employed in this paper. Results at 1300 r/min and 50% load indicate that the cooling pump and cooling fan together consume 7.66% of the recovered power. What＇s worse for the heavy load, cooling accessories may deplete of all the recovered power of the Rankine cycle system. Af- terwards, effects of the condensing pressure and water feeding temperature are investigated, based on which a cooling power consumption model is established. Finally, an overall efficiency optimization is conducted to balance the electric power gener- ation and cooling power consumption, taking condensing pressure, pressure ratio and exhaust bypass valve as major variables. The research suggests that the priority is to increase condensing pressure and open exhaust bypass valve appropriately at high speed and heavy load to reduce the cooling power consumption, while at low speed and light load, a lower condensing pressure is favored and the exhaust bypass valve should be closed making the waste heat recovered as much as possible. Within the sub-critical region, a larger pressure ratio yields higher overall efficiency improvement at medium-low speed and load. But the effects taper off at high speed and heavy load. For a given vehicular heavy-duty diesel engine, the overall e：＇ficiency can be improved by 3.37% at 1300 r/min and 25% load using a Rankine cycle system to recover exhaust energy. The improvement becomes smaller as engine speed and load become higher.