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521.
在全球风电市场稳步发展的背景下,发展中国家(地区)的风电市场也都呈现快速发展的趋势,在各国风电发展持续升温的前提下,未来我国风电发展潜力巨大。列举了非洲、印度、拉丁美洲、东欧、中东等5个发展中国家(地区)未来风电发展规划情况,在总结这些国家或地区风电发展特点的基础上,对我国未来风电发展提出建议。 相似文献
522.
523.
采用磷酸二氢钾活化原材料柚子皮,分别在300℃和600℃对活化后柚子皮进行炭化,制得吸附剂(CC300和CC600),通过静态吸附实验研究了炭化柚子皮对双酚A的吸附性能。采用比表面积分析仪对炭化柚子皮进行表征,实验考察了pH值、吸附时间和温度对双酚A吸附的影响,并详细研究了炭化柚子皮对双酚A的吸附行为和机理。结果表明,高温炭化柚子皮(CC600)吸附双酚A能力比低温炭化(CC300)的强,其吸附较好地满足Langmuir和Freundlich等温方程;动力学研究表明,其吸附速率快,在150min内能达到吸附平衡,准二级动力学模型较好地描述该吸附行为,相关系数高达0.99:计算了热力学参数△G、△H和△S的值,△G为负值,说明该吸附过程为自发过程。 相似文献
524.
HYSTAR Sediment Model: Distributed Two‐Dimensional Simulation of Watershed Erosion and Sediment Transport Using Time‐Area Routing
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An erosion and sediment transport component incorporated in the HYdrology Simulation using Time‐ARea method (HYSTAR) upland watershed model provides grid‐based prediction of erosion, transport and deposition of sediment in a dynamic, continuous, and fully distributed framework. The model represents the spatiotemporally varied flow in sediment transport simulation by coupling the time‐area routing method and sediment transport capacity approach within a grid‐based spatial data model. This avoids the common, and simplistic, approach of using the Universal Soil Loss Equation (USLE) to estimate erosion rates with a delivery ratio to relate gross soil erosion to sediment yield of a watershed, while enabling us to simulate two‐dimensional sediment transport processes without the complexity of numerical solution of the partial differential governing equations. In using the time‐area method for routing sediment, the model offers a novel alternative to watershed‐scale sediment transport simulation that provides detailed spatial representation. In predicting four‐year sediment hydrographs of a watershed in Virginia, the model provided good performance with R2 of 0.82 and 0.78 and relative error of ?35% and 11% using the Yalin and Yang's sediment transport capacity equations, respectively. Prediction of spatiotemporal variation in sediment transport processes was evaluated using maps of sediment transport rates, concentrations, and erosion and deposition mass, which compare well with expected behavior of flow hydraulics and sediment transport processes. 相似文献
525.
C. P. Vineetha C. A. Babu T. N. P. Nambiar 《International Journal of Green Energy》2016,13(2):191-199
Tapping of renewable energy sources like solar and wind is given great priority by power producers all over the world. Technical problems of linking them to the grid are solved. The cost constraints of utilizing renewable energy at specific locations are to be determined. In this work, a model is developed for grid tied hybrid power system (HPS) consisting of photovoltaic (PV) module and wind mill at the roof top of smart premises. The grid is capable of delivering and receiving energy. Objective function is formed with constraints taking into account the cost of PV module, wind mill, and grid tied inverter with controller. The constraints are rating of HPS and energy that can be delivered to the grid. Using this model, case studies were conducted in three locations in India, each location having two different demands. The results are presented. With the optimal rating of HPS, results shows that, conventional energy cost is higher. 相似文献
526.
M. M. Rahman Saad Mekhilef R. Saidur A. G. M. Mustayen Billah S. M. A. Rahman 《International Journal of Green Energy》2016,13(4):344-351
This article presents two mathematical models for drying mushrooms considering the shrinkage effect. Both the models consider the physical changes of mushrooms during drying using the diffusion equation. A convective term is presented in the first model while, in the second model, the effective diffusion co-efficient is employed. Although the diffusion co-efficient is mainly dependent on the water content of the mushrooms, both models are suitable for analyzing the drying process. Moreover, in this study it has been demonstrated that both models are equivalent. The Genetic Algorithmic process was used to estimate the parameter values in different conditions. The information regarding the moisture content and the thickness evaluation taken from the models shows the best fit with the experimental data. The mathematical models developed to simulate the drying curve of mushroom have been evaluated and compared. 相似文献
527.
The behavioral distribution of the atmospheric turbulence flow over the terrain with changes in a rough surface has become one of the most important topics of air pollution research, among such other topics as transportation and dispersion pollutants. In this study, a computational model on atmospheric turbulence flow over a terrain hill shaped with rough surface was investigated under neutral atmospheric conditions. The flow was assumed to be 2D and modeled using computational fluid dynamics (CFD) models, which were numerically solved using Reynolds-averaged Navier-Stokes equations. Rough surface conditions were modeled using a number of windbreak fences regularly spaced on the hill. The mean velocity and turbulent structures such as turbulence intensity and turbulent kinetic energy were investigated in the upwind and downwind regions over the hill, and the numerical models were validated against the wind-tunnel results to optimize the turbulence model. The computational results agreed well with the results obtained from the wind tunnel experiments. The computational results indicate that the mean velocity was observed to increase dramatically around the crest of the upwind slope of the hill. A thick internal boundary layer was observed with a fence on the crest and downwind region of the hill. The reversed flow and recirculation zone were formed in the wake region behind the hill. It was thus determined that turbulent kinetic energy decreases as the mean velocity increases. 相似文献
528.
Tore Haavaldsen Gro Holst Volden Jardar Lohne 《International Journal of Sustainable Engineering》2014,7(1):2-12
Assessing the sustainability of large public investment projects within the general framework of three-pillar thinking is a complex affair. Such ventures involve multiple actors – e.g. planners from various disciplines such as engineers, economists and social scientists, in addition to politicians, users and other people affected – each carrying with them particular agendas and priorities, and corresponding understandings of the concept of sustainability. In this paper, we propose to frame the concept of sustainability assessment within the context of investment projects, in order to enable communication between the multiple actors, to assess different impacts of an investment project against one another in a meaningful way and, ultimately, to enhance the commensurability of investment project alternatives. Our main idea is that there exist different levels according to which the assessment of sustainability ought to refer – operational, tactical and strategic – and that properly addressing these levels can permit the different actors to comprehend one another, and thereby allow for more clarity and positive action. 相似文献
529.
目前氨水作为脱硝还原剂用于燃煤锅炉SCR脱硝国内尚未普遍使用,尤其在大机组上的应用经验较少。通过对实际应用案例的分析,总结了运行经验,为氨水还原剂在大机组SCR的脱硝应用提供参考。 相似文献
530.
The public health and ecological impacts of volatile organic compound (VOCs) pollution have become a serious problem in China, arousing increasing attention to emissions control. In this context, this paper analyses the effectiveness of VOC reduction policies, namely pollution charges and environmental taxes at the national and industrial sector levels. It uses a computable general equilibrium model, which connects macroeconomic variables with VOC emissions inventory, to simulate the effects of policy scenarios (with 2007 as the reference year). This paper shows that VOC emissions are reduced by 2.2% when a pollution charge equal to the average cost of engineering reduction methods – the traditional approach to regulation in China – is applied. In order to achieve a similar reduction, an 8.9% indirect tax would have to be imposed. It concludes that an environmental tax should be the preferred method of VOC regulation due to its smaller footprint on the macroeconomy. Other policies, such as subsidies, should be used as supplements. 相似文献