抽水蓄能电站上库侧式进/出水口数值模拟

进/出水口是抽水蓄能电站输水系统的重要组成部分,其水力性能直接关系到抽水蓄能电站的运行和经济效益。利用CFD软件,对某抽水蓄能电站上库四孔侧式进/出水口进行数值模拟计算,模拟其在不同库水位、不同运行工况下的水力特性,包括水头损失、通道中流量分配及流速分布情况。结果表明,该方法得到的数值模拟结果均符合客观规律,与物理模型试验结果具有较好的一致性和精度,可实现对抽水蓄能电站上库侧式进/出水口水力特性的预测,对指导实际工程建设具有一定意义。     

江苏宜兴铜官水抽水蓄能电站上库及进／出水口研究

简要介绍了江苏省正在筹建的大型抽水蓄能电站-铜官山抽水蓄能电站，包括其在江苏电网中的作用、枢纽特征。并对该电站上库及进/出水口水工模型试验的方法、研究内容和水力损失及库区流态等主要成果进行了描述。获得的数据和结论可供同类工程设计、运行参考。     

江苏宜兴铜官山抽水蓄能电站上库及进/出水口研究

简要介绍了江苏省正在筹建的大型抽水蓄能电站——铜官山抽水蓄能电站 ,包括其在江苏电网中的作用、枢纽特征。并对该电站上库及进 /出水口水工模型试验的方法、研究内容和水力损失及库区流态等主要成果进行了描述。获得的数据和结论可供同类工程设计、运行参考     

抽水蓄能电站侧式进出水口体型优化的数值模拟

鉴于抽水蓄能电站进出水口因有进水和出水的双向水流,其体型对电站运行的影响较常规电站大,以某抽水蓄能电站为例,通过建立三维水动力数学模型,运用CFD软件对电站进行数值模拟,发现该电站不能达到工程设计需要,进而对导流隔墩尾部位置及中孔和边孔的扩散角进行了优化调整,对比分析了优化前后不同水位条件下发电和抽水时的水流和水头损失情况。结果表明,优化方案解决了原体型分流不均的问题,并减小了水头损失。     

抽水蓄能电站上水库流态CFD模拟分析

运用CFD软件Flow-3D和RNGκ-ε湍流模型模拟分析了抽水蓄能电站上水库的进/出水口位置及其形状对流态的影响,并模拟分析了某抽水蓄能电站上水库的流态变化,提出了优化建议。结果表明,上水库圆形库面、进/出水口前设置较长引水渠流态较好且利于主流扩散,当进/出水口两侧有一定距离时可减小环流对库岸的冲刷。     

抽水蓄能电站同发同抽水力特性VOF数值模拟

为了有效缓解电网突然出现的电力不平衡现象,同一个抽水蓄能电站不同水力单元机组同时分别发电及抽水运行,是对抽水蓄能运行及调度方式的一个重大创新措施。以某抽水蓄能电站上库为例,通过数学模型研究上库进/出水口在同发同抽工况下的库区水流流态、流道的水力特性、库区漩涡特性等水力参数的变化规律。结果表明,VOF方法可很好地模拟抽水蓄能同发同抽过程;同发同抽工况下,库区内进出水口附近局部水流流态与单向运行工况基本一致,但是两进/出水口之间形成连通的水流通道,库区内形成大范围横向流动,致使抽水单元大部分水流再次进入发电单元。     

提高抽蓄电站进/出水口过栅流速均匀性的数值模拟研究

为提高抽水蓄能电站进/出水口过栅流速均匀性，采用标准κ-ε紊流模型，对不同方案下的蛟河抽水蓄能电站进/出水口过栅水流流态进行了数值模拟。结果表明，在进/出水口其他尺寸符合常规的条件下，减少分流墩厚度(最小厚度取决于结构安全需求)可明显提高过栅流速均匀性。     

抽水蓄能电站侧式双进/出水口三维数值模拟

采用Realizable k-ε紊流数学模型对抽水蓄能电站侧式双进/出水口进流水流特性进行数值模拟,并将计算结果与物理模型试验的测量结果进行比较,验证了三维数值模拟计算的准确可靠性.模拟结果表明,该方法计算流体力学方便快捷,并可达到物理模型试验的精度.     

汽车散热器结构优化研究

散热器是汽车发动机冷却系统的重要组成部分.采用多孔介质模型对汽车散热器进行简化,对其温度场和流场进行了仿真计算.分别模拟计算了进、出水口位置以及水管排数不同时散热器的换热性能,分析比较了它们的换热特性和流动特性以获得进、出水口位置及水管排数对管带式散热器性能的影响,研究了散热器结构优化的方向.利用风洞试验台进行了试验,并将试验值和数值模拟值进行了对比分析,验证了数值模拟的正确性.     

抽水蓄能电站同发同抽工况下漩涡特性的研究

为探究抽水蓄能电站同发同抽工况的可行性,对某抽水蓄能电站进行物理模型试验研究发现,当电站最低淹没深度满足Gordon公式的要求时,在同发同抽工况下侧向进水口前观测到尺度和强度较大的立轴漩涡。通过分析对比单个水力单元单向发电工况与同发同抽工况的库区流态,得出在同发同抽工况下,抽水侧水体形成的沿岸回流与发电侧表面横流相互挤压后汇聚,对涡核区域水体施加附加剪切力,从而导致回流流速持续增大,产生吸气漩涡。针对产生漩涡的水动力学条件,提出抬高死水位和在进/出水口上方平台加设隔墙两种方案,达到消除同发同抽工况下的吸气漩涡的目的。研究成果可为抽水蓄能电站同发同抽工况研究提供参考。     

抽水蓄能电站引水系统设置气垫式调压室探讨

分析了抽水蓄能电站引水系统不同布置方案的水力特征及不同形式上游调压室的水力性能差异，经水力过渡过程比较计算阐明：气垫式调压室不但适用于抽水蓄能电站，而且在水力性能上具有独特的优越性。因此，在地质条件允许的情况下，气垫式调压室应作为抽水蓄能电站上游调压室的主要比选方案之一。     

Modelling a hydropower plant with reservoir with the micropower optimisation model (HOMER)

Hydropower with water accumulation is an interesting option to consider in hybrid systems, because it helps dealing with the intermittence characteristics of renewable energy resources. The software HOMER (version Legacy) is extensively used in research works related to these systems, but it does not include a specific option for modelling hydro with reservoir. This paper describes a method for modelling a hydropower plant with reservoir with HOMER by adapting an existing procedure used for modelling pumped storage. An example with two scenarios in southern Brazil is presented for illustrating and validating the method explained in this paper. The results validate the method by showing a direct correspondence between an equivalent battery and the reservoir. The refill of the reservoir, its power output as a function of the flow rate and installed hydropower capacity are effectively simulated, indicating an adequate representation of a hydropower plant with reservoir is possible with HOMER.     

Modeling studies for production potential of Chingshui geothermal reservoir

The Chingshui geothermal power plant was decommissioned in 1993 due to a continued decline in production. Although some geothermal exploration and field investigation had been exercised, the production potential of the reservoir is still not well understood. In this paper, numerical modeling approaches for characterization of the geothermal reservoir, investigation of reservoir production performance, and evaluation of exploitation scheme design are presented. At first, a site-scale refined grid numerical model was developed for simulating the natural state of Chingshui geothermal reservoir. Through the model, the production potential of the geothermal reservoir was estimated and the availability of water resources was assessed. We further built production model to simulate the production history during 1981–1993. From the production model, we can conclude that the abnormal drop of the reservoir production capacity is mainly caused by carbonate scaling. Potential production schemes with different reinjection designs were evaluated through the model. Simulation results indicated that a sustainable hot water production capacity of Chingshui geothermal reservoir is about 200 t/h without reinjection, and 300 t/h or even higher with reinjection which is enough for a 3 MWe power plant. The simulation results indicate that reinjection provides an effective approach for maintaining reservoir pressure during hot water/steam production.     

A stand-alone photovoltaic power system for remote villages using pumped water energy storage

The present paper regards the implementation of a stand-alone photovoltaic plant in which battery storage is partially replaced by a micro-hydraulic system. The plant was installed on Donoussa Island in the Aegean Sea, Greece to cover basic electricity needs of the remote village of Merssini (13 houses). Lighting, TV set and refrigerator were considered basic electricity needs for each house. The photovoltaic array consists of 300 photovoltaic modules of 60 W_p each, for a combined 18 kW_p total installed power. The micro-hydraulic system consists of a water pump of 6 kV A and a water turbine coupled with a DC generator of 7.5 kW and two identical water reservoirs of 150 m³ capacity each. During the day, the load is satisfied directly form the photovoltaic generator through an inverter (UPS unit of 25 kV A, 380 V-3 phases alternative current), while any energy surplus is directed to the pump for pumping water from the low level reservoir (at about 100 m altitude from sea level), to the high level reservoir (at about 200 m altitude from sea level). During the night, water is turbined to the low level reservoir providing energy to the load. There is also a battery bank of 186 cells of 2 V nominal voltage in series, with a total capacity of 100 A h. The batteries cover primarily load peaks. The paper presents first results and experience gained from the system performance.     

SSG wave energy converter: Design,reliability and hydraulic performance of an innovative overtopping device

The SSG (Sea Slot-cone Generator) is a wave energy converter of the overtopping type. The structure consists of a number of reservoirs one on the top of each other above the mean water level in which the water of incoming waves is stored temporary. In each reservoir, expressively designed low head hydro-turbines are converting the potential energy of the stored water into power. A key to success for the SSG will be the low cost of the structure and its robustness. The construction of the pilot plant is scheduled and this paper aims to describe the concept of the SSG wave energy converter and the studies behind the process that leads to its construction. The pilot plant is an on-shore full-scale module in 3 levels with an expected power production of 320 MWh/y in the North Sea. Location, wave climate and laboratory tests' results will be used here to describe the pilot plant and its characteristics.     

汽轮机油中带水原因分析与处理

汽轮机油中带水是机组常见问题之一,以广州恒运电厂7号机油中带水严重为例,通过对汽轮机带水原因分析,并采取相应的处理措施,消除了汽轮机油中带水现象,收到良好效果。     

广州地区地源热泵热水系统的应用研究

针对广州地区生活热水供应的现状,通过将地源热泵热水系统与几种常用的热水系统进行对比,同时,从政策、地质、气候等方面,论证了广州地区采用地源热泵热水系统的优势与可行性。介绍了本实验室建立的耦合型地源热泵实验平台和自主开发的适应于广州地区的地源热泵热水工程。通过对实际工程运行特性的分析,表明在广州地区采用地源热泵热水系统是可行的,节能效果显著。     

潘口水库蓄水运行对黄龙滩水电厂中长期发电调度的影响

堵河中下游的潘口水库正常蓄水运行后,将会对下游的黄龙滩水电厂发电调度产生较大影响。在潘口水库调度方式确定的情况下,利用有、无对比法,采用调度图和离散微分动态规划算法,研究了潘口水库正常蓄水运行后在丰、平、枯三个典型年对黄龙滩水电厂中长期发电调度的影响。结果表明,潘口水库的调蓄可明显提高平水年黄龙滩水电厂的发电量,降低其年发电耗水率;对于丰水年和枯水年,潘口水库调度期期初水位高于345 m时也可在一定程度上提高其发电效益;在潘口水库调度期期初水位低于345 m时,黄龙滩水电厂宜采用优化调度方式,并尽量提高其期初水位至245 m以上。     

广州蓄能水电厂水工运行总结与思考

为改进设计，提高中国抽水蓄能电站的建设管理水平，从水库库容、地下厂房抗振、渗漏、排水，高压隧洞充排水和安全监测系统等方面全面总结了广州蓄能水电厂20年的经验总结和教训。结果表明广州蓄能水电厂水工建筑物设计运行基本合理，但仍有一些值得改进的地方。     

Autocascade refrigeration system: Experimental results in achieving ultra low temperature

In this paper the experimental results of an autocascade refrigeration system for achieving ultra low temperature are presented. The plant is used to preserve tissue and cells. When the air temperature is equal to ?150°C in 0.25 m³ space, the required refrigeration power is about 250 W. The influence of the most meaningful variables is discussed with regard to the design of the plant. The experimental results show an acceptable time to reach the steady state in dependence of the finality of the plant. The working substance is a non‐azeotropic mixture consisting of hydrofluorocarbon (HFC) refrigerants in addition to argon and methane. Copyright © 2009 John Wiley & Sons, Ltd.