中国钢铁工业的系统节能和科学用能

 分析了自1980年以来中国钢铁企业吨钢能耗的下降趋势,应用吨钢能耗e-p分析法和c-g分析法,剖析了中国钢铁企业的能耗现状及其影响因素。结合热力学第一定律和第二定律,得出了同时使用“系统能效”和“能级差”方能从“数量”和“质量”两个方面实现科学用能的结论。在科学用能理论指导下,剖析了钢铁工业的节能潜力,指出科学地配置能源、科学地使用能源,科学地管理能源,深入挖掘“非平衡”状态下的节能潜力,将是下一个15年节能理论和技术的重要研究命题。     

Diagnostic Analysis of the Evolution Mechanism for a Vortex over the Tibetan Plateau in June 2008

Based on the final analyses data (FNL) of the Global Forecasting System of the NCEP and the observational radiosonde data,the evolution mechanism of an eastward-moving low-level vortex over the Tibetan Plateau in June 2008 was analyzed.The results show that the formation of the vortex was related to the convergence between the northwesterly over the central Tibetan Plateau from the westerly zone and the southerly from the Bay of Bengal at 500 hPa,and also to the divergence associated with the entrance region of the upper westerly jet at 200 hPa.Their dynamic effects were favorable for ascending motion and forming the vortex over the Tibetan Plateau.Furthermore,the effect of the atmospheric heat source (Q1) is discussed based on a transformed potential vorticity (PV) tendency equation.By calculating the PV budgets,we showed that Q1 had a great influence on the intensity and moving direction of the vortex.In the developing stage of the vortex,the heating of the vertically integrated Q1 was centered to the east of the vortex center at 500 hPa,increasing PV tendency to the east of the vortex.As a result,the vortex strengthened and moved eastward through the vertically uneven distribution of Q1.In the decaying stage,the horizontally uneven heating of Q1 at 500 hPa weakened the vortex through causing the vortex tubes around the vortex to slant and redistributing the vertical vorticity field.     

Dissipation of Turbulent Kinetic Energy in a Tundish by Inhibitors with Different Designs

Turbulent flow of liquid steel and its control is studied using different geometries of turbulence inhibitors. Four designs of turbulence inhibitors were characterized through experiments of tracer injection in a water model and mathematical simulations using the Reynolds Stress Model (RSM) of turbulence. Inhibitor geometries included octagonal‐regular, octagonal‐irregular, pentagonal and squared. A layer of silicon oil was used to model the behaviour of tundish flux during steel flow. Fluid flows in a tundish using these geometries were compared with that in a bare tundish. Experimental and simulation results indicate that the flow in a bare tundish and a tundish using turbulence inhibitors open large areas of oil close to the ladle shroud due to strong shear stresses at the water‐oil interface with the exception of the squared inhibitor. Oil layer opening phenomena are explained by the high gradient of the dissipation rate of turbulent kinetic energy. Using the squared inhibitor the kinetic energy reports a high gradient from the tundish floor to the free bath surface as compared with other geometries.     

An Assessment of Storage Terms in the Surface Energy Balance of a Subalpine Meadow in Northwest China

T The heat storage terms in the soil-vegetation-atmosphere system may play an important role in the surface energy budget. In this paper, we evaluate the heat storage terms of a subalpine meadow based on a field experiment conducted in the complex terrain of the eastern Qilian Mountains of Northwest China and their impact on the closure of the surface energy balance under such non-ideal conditions. During the night, the average sum of the storage terms was -5.5 W m-2, which corresponded to 10.4% of net radiation. The sum of the terms became positive at 0730 LST and negative again at about 1500 LST, with a maximum value of 19 W m-2 observed at approximately 0830 LST. During the day, the average of the sum of the storage terms was 6.5 W m-2, which corresponded to 4.0% of net radiation. According to the slopes obtained when linear regression of the net radiation and partitioned fluxes was forced through the origin, there is an imbalance of 14.0% in the subalpine meadow when the storage terms are not considered in the surface energy balance. This imbalance was improved by 3.4% by calculating the sum of the storage terms. The soil heat storage flux gave the highest contribution (1.59%), while the vegetation enthalpy change and the rest of the storage terms were responsible for improvements of 1.04% and 0.77%, respectively.     

能源总厂构建“大安全”管理模式的实践与思考

武钢能源总厂把安全管理的范围与内容从传统的人身安全扩大到生产过程中的设备、运行、人身、交通、消防等各个方面,探索了安全管理的新模式。     

The thermal capacity and enthalpy of gadolinium sesquiselenide over a wide temperature range

Measurements have been made on the thermal capacity of γ-Gd₂Se₃ at 58.88–298.34 K. Values have been obtained for the thermal capacity, entropy, reduced Gibbs energy, and enthalpy under standard conditions: C°_p = 125.87 ± 0.5 J· mole⁻¹ · K⁻¹; S°(298.15 K) = 196.5 · 1.6 J · mole⁻¹ · K⁻¹; Φ°(298.15 K) = 103.6 ± 1.6 J · mole⁻¹ · K⁻¹; H°(298.15 K)-H°(0) = 27681 ± 138 J · mole⁻¹. The enthalpy of Gd₂Se₃ has been measured and the major thermodynamic functions have been calculated for the solid and liquid states over the temperature range 450–2300 K. The temperature dependence of the enthalpy in the ranges 300–1800 K and 2000–2300 K are represented: H°(T)-H°(298.15 K) = = 1.1949 · 10⁻² · T² + 122.38 · T + 347402 · T⁻¹ − 38716 and H°(T)-H°(298.15 K) = 262.81 · T-− 196047, respectively. The calculated temperature, enthalpy, and entropy of melting for Gd₂Se₃ are: T_m = 1925 ± 40 K, Δ_mH° (Gd₂Se₃) = 68.5 kJ · mole^-1, Δ_mS°(Gd₂Se₃) = 35.6 J · mole⁻¹ · K⁻¹. __________ Translated from Poroshkovaya Metallurgiya, Nos. 3–4(448), pp. 56–61, March–April, 2006.