Optimal coordination of wind-hydro-thermal based on water complementing wind

The increasing integration of wind power into the existing power system demands for effective strategies to deal with wind intermittency and uncertainty. Relying solely on thermal power to cover wind uncertainty will sacrifice the operating efficiency and economy of thermal generators. In view of this, the adjustable hydropower is preferred for complementing wind fluctuation and uncertainty and the coordinated dispatch problem of wind-hydro-thermal power is established. Based on a newly designed water supplementing wind strategy, the original complex problem is decomposed into wind-hydro subproblem and thermal subproblem. A novel stochastic constraint related to wind power uncertainty is proposed and handled according to stochastic programming theory. By introducing the concept of expected breed rate and elitist preservation strategy, the particle swarm optimization (PSO) algorithm is improved and combined with the exterior penalty function method for solving the complete optimization problem. Optimal generation scheduling schemes that can make full use of wind energy and ensure efficient and economic operating of thermal generators are obtained by the proposed approach. Meanwhile the coordinating operation of wind, hydro and thermal power under different water resources and wind penetrations respectively are revealed and discussed.     

Oxygen deficiency assisted synthesis of network-like tungsten carbide-carbon nanotubes composites for methanol oxidation

3D network-like tungsten carbide-carbon nanotubes composites were in-situ synthesized by using W₁₈O₄₉ as the precursor. The sea urchin like W₁₈O₄₉ with abundant oxygen defects was designed and fabricated to act as not only the source of tungsten, but also the catalyst to initiate the growth of carbon nanotubes. Distinct from carbon nanotubes-supported tungsten carbide, the obtained tungsten carbide-carbon nanotubes display an electroconductive network. In the effective system, tungsten carbide particles cracks due to mechanical stress during the growth of carbon nanotubes but the fragments still connect to the carbon nanotubes. It provides both conductive network and numerous active sites for the ideal electrocatalysts. Finally the tungsten carbide-carbon nanotubes are evaluated as an alternative catalyst for methanol oxidation reaction after being platinized. The peak current density of optimized sample reaches 1350 mA mg^-1 Pt which is more than twice that of commercial Platinum Carbon.     

近50多年来北洛河水沙变化特征及原因分析

北洛河流域是黄河粗泥沙的主要来源区之一.基于北洛河流域(氵状)头水文站1950-2006年逐年降水量、径流量和输沙量数据,分析了北洛河径流与输沙变化特征.Mann-Kendall、Spearman检验以及线性趋势拟合均表明,降水量、径流量和输沙量均呈显著减少趋势;利用单位降水产流产沙量距平累积曲线分析表明,北洛河单位降水产流产沙量变化可以分为枯水平沙期、丰水丰沙期、枯水平沙期、丰水枯沙期、丰水丰沙期和枯水枯沙期等6个阶段.分析其变化原因认为,降水是影响径流输沙变化的主要自然因素,其中降水径流关系最为密切;水利水保措施的实施、毁林开荒、修路开矿等破坏活动、国家政策以及法律法规的颁布实施等人类活动同样影响径流、输沙量的变化.     

太原市亲贤地垒区地下热水成因及地热资源评价

为了科学合理开发利用地热资源,在分析太原市亲贤地垒区地热田形成背景的基础上建立了地热田地质模型,分析了热水补给来源和运移机制,并对地热资源进行了评价。结果表明,太原市亲贤地热田地热水来源于大气降水补给,属滞流型无氚老水;亲贤地垒区热田具备了良好的盖层、热储、热源和水循环通道等地质条件,热水是经深循环(受深部热源加热)而形成的;热水开采量不能超过3 600m3/d,热水储存资源量为9.76×108 m3,可实现开采的地热能折合标准煤约1 500×104t。     

Construction of photocatalytic plates for hydrogen production from photoreforming of glycerol

The photocatalytic production of hydrogen has been reported as an attractive strategy given the possibility of using renewable sources such as sunlight and biomass. The scalability of the process involves optimizing the design of the reaction system, minimizing the cost and time spent on the stages of separation, purification and reuse of the catalyst. This work demonstrates the application of photocatalytic plates impregnated with TiO₂ doped with small doses of platinum (Pt) in the photoreforming of glycerol under visible radiation. The optimized amount of catalyst was 25 mg, corresponding to an average hydrogen production rate in 3 h of reaction of 316 mmol H₂.h⁻¹.m⁻², this value being independent of the platinum concentration range tested (0.1%–1.0%, w/w). The kinetic behavior of the photocatalytic plates was similar to the application of the catalyst in powder form. The presence of 0.3% platinum in the catalyst composition led to the maintenance of photocatalytic stability for 7 consecutive application cycles, indicating operational viability without appreciable loss of performance, brings good prospects for expanding the scale of the process and allowing the development of continuous flow operations.     

EUROSEM模型对晋西黄绵土坡面侵蚀过程的模拟应用

晋西黄绵土坡面因其土壤、降雨等条件极易造成严重水土流失,本文基于不同坡长(2、3、4m)与雨强(60、90、120 mm/h)组合方式下的野外人工模拟降雨试验,应用EUROSEM模型对坡面径流侵蚀过程及产流产沙总量进行模拟,通过对比分析模拟值与实测值,评价该模型对晋西黄绵土坡面土壤侵蚀过程的模拟效果及在该区的适用性.结...