大连市建设潮汐电站的可行性分析

介绍当前国内能源形势,综述潮汐发电的基本原理、站址选择原则、电站效益和发展前景,并以辽宁省大连市为例分析其建设潮汐电站的条件。文章指出,潮汐发电将在未来我国的能源结构中占有一席之地,在大连市建设潮汐电站是可行的,并推荐三处宜建电站的海湾以供选择。     

我国海洋能技术的发展

一潮汐发电技术 我国现代潮汐能的开发利用,从1955年在福建、广东兴建潮汐动力站开始,随后就进入了潮汐电站建设时期,至今大致经历了三个时期。     

海洋能知识讲座(5)我国海洋能技术的发展

一潮汐发电技术 我国现代潮汐能的开发利用,从1955年在福建、广东兴建潮汐动力站开始,随后就进入了潮汐电站建设时期,至今大致经历了三个时期. 第一个时期1958年前后.广东省顺德县首先开始兴建小型潮汐电站,很快发展到浙江、山东、江苏、上海、福建、辽宁等省市.     

潮汐发电的开发及技术问题

一、国外潮汐发电的发展 1912年,德国首先在石勒苏益格-荷尔斯太因的布苏姆湾建成一座小型潮汐电站。接着法国在布列太尼半岛,兴建了一座功率为2500匹马力的潮汐电站,供布雷斯特镇的全部用电。1919年起,美国和加拿大开始联合研究芬地湾。到1935～1936年,美国在芬地湾内的科勃斯科湾开始兴建大型潮汐电站。其最大潮差为7.5米,设计装机总容量达21万千瓦。动工之后,共化费了4300万美元的投资。其后,被迫中途放弃原定计划。1928     

重视潮汐电站的开发与利用

分析了潮汐电站发展的内外环境，并就中国的实际情况提出应加快潮汐电站的开发与利用。     

国外文摘

加拿大将兴建大型潮汐电站加拿大的第一套潮汐发电装置已于1983年夏季进行了试运行,该装置建在东海岸安纳波利斯入海处,容量为2万千瓦,投资约4600万加拿大元。加拿大计划在这套试验装置取得经验的基础上,在东海滨魁增克的芬地湾(据称世界最大潮汐发生在此,潮高达20米)建设一座380万千瓦的大型潮汐电站。目前的这套试验机组,水轮机是4叶片、直径7.6米,低头贯流式的,重约445吨,发电机组直径为13.5米,重约90吨,全由加拿大自己设计和制造。马驰摘自《电气评论》(英)1983年4月号     

世界首座潮汐发电站在英建成

英国科学家在德文郡北部距离海岸1.3km的海洋中,建造了世界第一座潮汐发电站。这个永久性的潮汐发电装置所发的电力将于今年8月并入全国电网。这台潮汐发电机采用单转子发电系统,装有一个直径11m的叶轮,工作时可产生300kW的电力。发电机主体部分安装在一个活动支架上,发电时处于水下,需要维修时可浮出水面。这台潮汐发电机也是一台实验机,它将为今后大规模开发潮汐发电提供技术数据。这台潮汐发电机的样子与现代风力发电机很相像,工作原理也完全相同,所不同的是:风力发电机以风为动力,而潮汐发电机以海洋水流为动力。潮汐发电的支持者认为,…     

有趣的环保发电方式

潮汐发电 潮汐发电就是在海湾或有潮汐的河口筑一座拦水堤坝，形成水库，并在坝中或坝旁放置水轮发电机组，利用潮汐涨落时海水水位的升降，使海水通过水轮机推动水轮发电机组发电。从能量的角度说，就是利用海水的势能和动能，通过水轮发电机转化为电能。潮汐发电的优点是成本低，每度电的成本只相当于火电站的1／8。     

潮汐电站水轮机过流部件的腐蚀及防护

潮汐电站水轮机过流部件的腐蚀影响着电站的安全稳定运行。文中分析了电化学腐蚀和空蚀两种主要腐蚀的机理,并结合江厦潮汐试验电站介绍了国内外潮汐电站的先进防护技术。     

含潮汐电站的海岛微网多目标优化调度

潮汐能是一种蕴藏量巨大的可再生能源,且潮汐能发电具有周期性和可预见性。然而现有海岛供电方案中少有考虑海岛自身拥有这一良好的天然条件。提出了一种以潮汐发电为主,配合风电场、抽水蓄能电站以及柴油发电机组的孤网海岛供电方案。对潮汐电站、风电场、抽水蓄能电站以及柴油机组分别建模,考虑各自的运行状况和约束条件以及负荷需求,提出了海岛微网多能互补的优化调度的方案。通过对比多个不同的典型场景,验证了该方案及优化调度模型的可行性和有效性。 关键词： 海岛;潮汐发电;风电;抽水蓄能电站;优化调度     

Resource analysis of the Chinese society 1980–2002 based on exergy—Part 2: Renewable energy sources and forest

This second part is the continuation of the first part on fossil fuels and energy minerals. The major renewable energy sources and forest products entering the Chinese society from 1980 to 2002, including sunlight, wind power, tidal power, wave power, geothermal power and heating, biomass, hydroelectric resource and forestry products, are calculated and analyzed in detail in this paper. The solar exergy inputs from solar photovoltaics and solar collectors, including water heater, solar oven and solar building, are calculated and discussed. The development of the wind power plant is presented. Major tidal power plants, which are still working, are addressed. Wave power devices and plants are introduced. Geothermal resources, mainly for power generation and heating, associated with distribution, are depicted. The utilization of biomass, embracing firewood, straw and biogas, which served as the main obtainable local resources for private consumption and production in the rural areas, is illustrated. Development of hydroelectric resources as complement to scarce fossil fuels is represented, of which the small hydropower project adapted for rural areas is emphasized. Finally, forest products from timber forest and economic forest are presented, with the forestation, reproducing, tending areas and sum of odd forestation trees being manifested.     

锅炉AG-2脱硫工艺的运行分析

随着国家对大气环境质量控制标准的日益提高.火力发电厂烟气脱硫势在必行.AG-2脱硫工艺不耗水、不造成二次污染、反应产物便于回收.且设备简单、投资小、运行维护方便及运行费用低,特别合适老机组的改造.对广州发电厂NG-220/9.8-M9型220 t/h燃煤锅炉的AG-2脱硫工艺从稳定燃烧、受热面的影响、脱硫产物以及静电除尘器除尘效果影响和锅炉效率等方面进行讨论.分析锅炉在采用AG-2脱硫工艺后对运行的安全经济影响,可为同类电厂脱硫改造提供参考.     

The role of tidal asymmetry in characterizing the tidal energy resource of Orkney

When selecting sites for marine renewable energy projects, there are a wide range of economical and practical constraints to be considered, from the magnitude of the resource through to proximity of grid connections. One factor that is not routinely considered in tidal energy site selection, yet which has an important role in quantifying the resource, is tidal asymmetry, i.e. variations between the flood and ebb phases of the tidal cycle. Here, we present theory and develop a high-resolution three-dimensional ROMS tidal model of Orkney to examine net power output for a range of sites along an energetic channel with varying degrees of tidal asymmetry. Since power output is related to velocity cubed, even small asymmetries in velocity lead to substantial asymmetries in power output. We also use the 3D model to assess how tidal asymmetry changes with height above the bed, i.e. representing different device hub heights, how asymmetry affects turbulence properties, and how asymmetry is influenced by wind-driven currents. Finally, although there is minimal potential for tidal phasing over our study site, we demonstrate that regions of opposing flood- versus ebb-dominant asymmetry occurring over short spatial scales can be aggregated to provide balanced power generation over the tidal cycle.     

Far-field dynamics of tidal energy extraction in channel networks

Tidal hydrokinetic power generation involves the conversion of the kinetic power in swiftly moving tidal currents to renewable electricity. Resource assessment is critical to understand the tidal hydrokinetic potential, but is complicated by a number of factors, including far-field effects. These are changes to the tidal regime caused by the increased resistance to flow as power is extracted from a channel network. This study addresses far-field effects in four prototypical channel networks: multiply-connected flow around an island, a branching network in which the flow bifurcates but does not converge downstream, and a network with multiple constrictions in series. These networks are modelled as one-dimensional channels with hydrokinetic power extraction in high current constrictions. Changes to tides, transport, frictional power dissipation, and kinetic power density are quantified for a range of extraction options. Depending on the type of network, the tidal regime may be either locally augmented or reduced by kinetic power extraction. The changes to kinetic power density throughout the network have important implications for resource assessment, particularly for networks with multiple extraction sites. Results suggest that existing analytical methods tend to over- or under-estimate the hydrokinetic resource because they do not allow for changes to the tidal forcing as a consequence of extraction. In general, site-specific numerical modelling is required to quantitatively predict far-field extraction effects and assess the hydrokinetic resource.     

Status and potentials of tidal in-stream energy resources in the southern coasts of Iran: A case study

Interest in renewable energy in Iran has increased continually over the past decade. Iran has an excellent hydro power energy resource and the use of this resource will assist in the development of a sustainable energy future. Iran – with its many narrow channels and significant tidal range – might be expected to have considerable potential for tidal current power generation. The Khowr-e Musa Bay is a large coastal embayment on the south-western coast of Iran in which the peak tidal currents exceed 2 m/s. It is therefore a promising site for tidal stream power. The assessment employed a statistical method, for estimating tidal current energy resource at the selected site, during one lunar month (since 6 November 1996 to 7 December 1996). With the introduction of constraints and limitations, the technical, practical, accessible and viable tidal current energy resources were obtained.     

潮流能发电装置输出功率异常数据识别方法研究及应用

在分析潮流能发电装置输出功率数据存在异常值的原因的基础上,讨论潮流能发电装置输出功率异常数据的判别方法,采用潮流流速区间精细划分和四分位判别相结合的方法,对每个潮流流速区间内的潮流能发电装置输出功率异常值进行识别与剔除。结果表明,该异常数据识别方法不仅能使得剔除异常数据后的潮流能发电装置输出功率图谱能更真实地表征被测试潮流能发电装置的输出功率特性,而且可提高潮流能发电装置平均输出功率和平均转换效率的计算准确度。     

Impact of different operating modes for a Severn Barrage on the tidal power and flood inundation in the Severn Estuary,UK

The Severn Estuary has a spring tidal range approaching 14 m and is regarded as having one of the highest tidal ranges in the world. Various proposals have been made regarding the construction of a tidal barrage across the estuary to enable tidal energy to be extracted. The barrage scheme originally proposed by the Severn Tidal Power Group (STPG) would be the largest project for tidal power generation in the world if built as proposed. Therefore, it is important to study the impact of different operating modes for this barrage on the tidal power output and flood inundation extent in the estuary. In this paper, an existing two-dimensional hydrodynamic model based on an unstructured triangular mesh has been integrated with a new algorithm developed for the estimation of tidal power output, which can account for three barrage operating modes, including ebb generation, flood generation, and two-way generation. The refined model was then used to investigate the impact of different barrage operating modes on the tidal power output and the associated extent of flood inundation along the Severn Estuary. Predicted results indicate that the mode of flood generation would produce the least electrical energy and cause a larger reduction in the maximum water levels upstream of the barrage. Two-way generation would provide an improvement to these conditions, and produce an equivalent amount of electricity to that from ebb generation, with a low installed capacity and a small loss of intertidal zones. Therefore, the mode of ebb generation or two-way generation would appear to be a preferred option for power generation, because both would offer benefits of acceptable electrical energy and reduced flood risk.     

Numerical model evaluation of tidal stream energy resources in the Ría de Muros (NW Spain)

The Ría de Muros is a large coastal embayment on the north-western coast of Spain in which the peak tidal currents exceed 2 m/s. It is therefore a promising site for tidal stream power. The key point when assessing this resource is the accurate estimation of the tidal currents. In this work a finite difference numerical model is used for this purpose. The model solves the vertically integrated Navier–Stokes hydrodynamics and transport equations. It is validated with in situ velocity measurements performed by means of an acoustic Doppler current profiler (ADCP). Thereafter the tidal flow velocities and the corresponding power densities are computed. The largest values are found in a section of the inner ria, in which two points are selected for a detailed assessment of the resource. The model is then run to compute the tidal stream and the corresponding power density at these points during a 14-day period, so as to cover the spring–neap cycle. The power density curve thus obtained is numerically integrated to compute the annual energy output that can be obtained by a tidal stream power plant at each location.     

Exceeding the Betz limit with tidal turbines

The Betz limit sets a theoretical upper limit for the power production by turbines expressed as a maximum power coefficient of 16/27. While power production by wind turbines falls short of the Betz limit, tidal turbines in a channel can theoretically have a power coefficient several times larger than 16/27. However, power extraction by turbines in large tidal farms also reduces the flow along the channel, limiting their maximum output. Despite this flow reduction, turbines in tidal farms can produce enough power to meet a stricter definition of what it means to exceed the Betz limit, one where the maximum power output of a turbine at the reduced flow exceeds the maximum output from a single Betz turbine operating in the unreduced flow. While having a power coefficient >16/27 is easily achieved by turbines in a channel, generating enough power to meet this stricter definition of exceedance is much more difficult. Whether turbines meet this stricter definition depends on their number, how they are arranged and tuned, and the dynamical balance of the channel. Arranging a tidal turbine farm so that the turbines within it exceed the stricter Betz limit would give tidal turbine farms an economic advantage over similarly sized wind farms. However, exceeding the stricter limit comes at a cost of both higher structural loads on the tidal turbines and the need to produce power from weaker flows. Farms in a channel loosely based on the Pentland Firth are used to discuss exceedance and structural loads.