太阳能发电技术

阐述了太阳能发电技术的基本原理和重要意义,介绍了有关太阳能的基础知识和太阳能电站的发展现状,对普及太阳能发电技术及从事太阳能电站设计、运行及维护的工程技术人员具有参考意义.     

电磁流量计测量直管内速度及管长的CFD 研究

电磁流量计是一种广泛采用的流量测量仪表,测量直管长度对于保证测量管内流速轴对称分布及电磁流量计计量精度起着关键性作用.本文采用CFD数值手段对电磁流量计测量直管长度及管内流速轴对称分布特性展开研究.为了准确地研究流速分布的轴对称特性,提出了定量衡量流速分布轴对称程度的速度对称偏差度,并基于此研究了不同内径、不同过流量条件下测量管内的流速分布轴对称特性和电磁流量计对测量直管长度的要求,为电磁流量计的检定、安装、应用提供科学理论依据,为依托项目建立高精度流量计量标准装置奠定基础.     

电力联营市场的统一出清报价模型分析

介绍在电力联营市场的模式下基于拉格朗日最优原理的统一出清电价模型,以不同的市场参与竞价机组组合分析系统边际价格的计算步骤,通过算例分析这种报价方式存在的问题,并以市场力指标计算示例中市场力的影响结果,分析存在的问题和解决的方法。     

An Initial Inventory and Indexation of Groundwater Mega-Depletion Cases

The state of groundwater systems worldwide is presently not well defined, and in particular there is little context for agencies responsible for managing water resources to evaluate occurrences of groundwater depletion against other cases globally. In this study, an initial inventory of groundwater depletion problems is compiled and ranked to identify the world’s most critical cases, i.e. situations of groundwater mega-depletion. The ranking is based on an indexed approach that considers overdraft, drawdown and subsidence, plus the importance of the resources in terms of population-dependency and rates of extraction. The five most highly ranked depleted aquifers of the world include the shallow aquifers of the Hai River Plain (China), the Altiplano region (Spain), the Mexico Basin (Mexico), the Huang River basin (China) and the California Central Valley (USA). An abridged account of modelling to assess drawdown is described for the Hai River Plain, revealing that despite recharge in the order of 13,000 GL/yr, an overdraft of about 8,000 GL/yr is occurring to support the vast population of the region. This has led to up to 100 m of drawdown in places and reports of subsidence of several metres. The Hai River situation demonstrates that falling water levels may not act to alleviate pumping stresses; a symptom of unchecked extraction and an exemplary illustration of the tragedy of the commons. The causal factors leading to mega-depletion are varying across the globe and each mega-depletion case contains unique elements, although population appears to be an important factor.     

An Integrated Groundwater Management Mode Based on Control Indexes of Groundwater Quantity and Level

Groundwater is an important source of freshwater throughout the world. Due to over-exploitation of groundwater over many years, a number of potential adverse hydrogeological problems have raised. To reduce such adverse effects, it is necessary to carry out strict groundwater management in over-exploited areas. In this study, quantity-level binary control management mode has been developed in Tianjin. Initially, the management is the key to determine control levels of groundwater including the blue line levels (proper levels) and red line levels (warning levels), the blue line levels can be determined by the ground settlement recovery scenario, and the red line levels can be determined through planning groundwater exploitation scenarios. By comparing the real-time observed groundwater data with the blue levels and red levels the management grade of groundwater levels which are present, can thus be identified. Secondly, the corresponding management strategies would be determined by the management grade. On this basis reasonable groundwater levels and mining schemes can be made. Finally, the water quota for each sector can be optimized and adjusted in real time according to the binary groundwater management methodology established in this study. Thus, the exploitation of groundwater can be monitored and dynamically managed by the real-time monitoring levels and the sustainable utilization of groundwater resources can be achieved. To achieve all the objectives mentioned above, it is necessary to provide a powerful tool through the utilization of a numerical model for groundwater management. Based on geological and hydrogeological conditions in Tianjin city, a three-dimensional numerical groundwater flow model was established by coupling a one-dimensional soil consolidation model with MODFLOW model. Through calibration and verification, the model showed good simulation accuracy. It proved that the new management mode can provide a scientific basis for groundwater management.     

Optimization of Industrial Structure Considering the Uncertainty of Water Resources

This paper developed a stochastic linear fractional programming model for industry optimization allocation base on the uncertainty of water resources incorporating chance constrained programming and fractional programming. In this paper, the stochastic linear fractional programming is used in the real word. The development SLFP has the following advantages: (1) The model can compare the two aspects of the targets; (2) The model can reflect the system efficiency intuitively; (3) The model can deal with uncertain issues with probability distribution; (4) The model can give different optimal plans under different risk conditions. The model has a significant value for the industry optimization allocation under uncertainty in local and areas to achieve the maximum economic benefits and the full use of the water resources.     

Self-Optimization Simulation Model of Short-Term Cascaded Hydroelectric System Dispatching Based on the Daily Load Curve

Short-term optimization dispatching of cascaded hydroelectric system with day (or week) cycle is of great value in practical implementation, such as improving grid stability, more power benefits. This study proposes a short-term self-optimization simulation model for cascaded hydroelectric system dispatching, which balances the requirements both of the generation side and the demand side. Three conflicting objectives for the management of hydropower generation are incorporated in the cascaded hydroelectric system. And in this model, the reasonable physical factors are chosen to coordinate the contradiction. According to the characteristics of the self-optimization simulation technique, for example clear physical meaning, more perfect simulation, no dimension limitation, artificial adjustment with the accumulated experience and so on, a new solving idea for this model is set up. And the new operation model is illustrated in the middle reaches of the Chinese Jinsha River, where eight cascades are planned. Considering the different startup time and combinations, the results of the joint operation compared to the single reservoir operation has provided important demonstration for the investment entities, simultaneously the solving efficiency and quality of this model are good for implementing in practical.     

山东沂沭泗河骨干工程洪水标准适应性分析研究

分析了沂沭泗河流域治理规划要求和60年来防洪工程建设现状,指出解决沂、沭、泗河中下游洪水出路问题是一项系统工程,目前中下游重要防护区和重要城市防洪标准要求总体达到了50年一遇,但骨干河道上游段堤防矮小、防洪标准不足20年一遇,湖东堤保护区范围内重要厂矿企业区部分堤段防洪标准亦不足50年一遇,另外部分城区段设防标准较低。这些现状与山东沂沭泗河流域作为省委省政府提出的"一体两翼"经济发展战略中的南翼———鲁南经济带的地位不相称,针对未来经济社会发展对其防洪保障的更高要求,提出了规划设想。     

黄河流域综合规划控制性指标的研究与设置

流域综合规划控制性指标,是为规范流域不同河段的开发利用活动和控制开发强度,以及实施全流域综合管理提供依据,对相关经济社会发展活动必须划定的不可逾越的"红线"或"底线"。针对不同河段及区域治理开发与保护的任务,从防洪(防凌)、水资源管理、河道内生态环境用水及断面下泄水量等三个方面,在黄河流域综合规划中研究设置了防洪(防凌)标准、设防流量、防凌库容、平滩流量、地表水用水量、地表水耗水量、地下水开采量、万元工业增加值用水量、大中型灌区灌溉水利用系数、水质目标、COD入河量、氨氮入河量、河道内生态环境用水量和断面下泄水量等14项主要控制指标,作为制定规划实施方案和进行综合管理的依据。     

北京市地下水取水井普查初步成果及其应用的思考

北京市第一次水务普查共有10个专项,地下水取水井专项普查对象是地下水取水井、地下水水源地和水源热泵系统。通过对普查成果中各行业机电井数量、计量安装、成井时间、井深等方面的统计,结合管理存在的问题,提出通过加强机电井审批管理与监督,加快制定农用机电井报废管理办法等措施,从而为实现全面、动态、有效地管理北京市地下水取水井提供技术支撑,最终为北京市落实最严格水资源管理打下坚实的基础。