近海区域风速数值模拟试验分析

在可持续能源发展战略的实施中，风能等可再生能源的开发利用是重要的战略选择。其中风能资源的评估是其开发利用的关键，如何利用有限的观测资料进行资源评估和分析就成为迫切需要解决的问题。该文利用中尺度气象模式MM5对海上风场进行模拟分析，模拟结果在风的分布趋势很好与多年平均实况吻合，为我国海上风资源的开发利用提供有力的科学依据。     

岛屿型复杂地形地貌条件下有效风能分布的甚高分辨率数值模拟

利用MM5作为风能模拟模式,以地形复杂、气候背景特殊的海陵岛地区为研究区域,采用甚高分辨率(水平分辨率200m,最高垂直分辨率是10m)的模式设计,模拟了秋季海陵岛地区的风资源分布。研究表明,中尺度数值模式MM5的甚高分辨率的模式设计可以作为复杂海岛地形风资源评估的有效手段;海陵岛地区有效风能密度的大值区多数位于150～200W·m~(-2)之间,这说明我国沿海地区复杂地形地貌条件下潜在的风能资源完全可以开发利用,并需要更加深入而客观的评估。     

复杂地形条件下风电场风能资源评估研究-以西南某风电场为例

对于复杂地形条件下的风电场风能资源评估,不能只局限于对测风塔及气象站资料的评估。本文通过讲述复杂地形条件下风能资源评估基本流程,利用已有的测风塔资料和先进的流体力学软件,对风电场进行风能资源分布研究,为进一步合理开发风电场风能资源提供了有利的技术支持。     

中国风能开发利用的风环境区划

基于大气边界层气象和气候学理论分析以及中尺度数值模拟,采用秒级探空气象资料和典型地形激光雷达观测资料,依据风能利用高度内总体风能资源开发潜力,划分出9个风环境区。年平均风能环境指数最高的风环境区是北方通风廊道,其次是东北平原,最低的是青藏高原下游地区。发现在稳定大气条件下,风能利用高度内的平均风速垂直变化呈两层分布形态,下层平均风速随高度的增速比上层大2～5倍。下层风速的垂直变化取决于地表特征,上层则受上游大地形造成的局地环流影响,由此形成不同风环境区风能资源特性的差异。最后给出构建不同地形条件下平均风廓线计算方法的建议。结论可为中国风能资源评估理论拓展与数值模拟、风电场选址和适用复杂地形条件的风电机组设计提供科学支撑。     

风资源评估中WindSim水平分辨率的敏感性试验

利用基于计算流体力学(CFD) 的风能资源评估系统软件WindSim,在不同水平网格分辨率条件下对我国黄土高原地区陕西靖边县境内某风电场2010年7月~2011年6月的风资源情况进行了模拟,并将模拟结果与测风塔观测结果进行了对比分析。结果表明,在低水平网格分辨率下,WindSim对风能资源的空间分布模拟主要以海拔高度为基础,对局地地形的影响并不能很好地反映,模拟风速误差较大;提高分辨率后,对风能资源空间分布的模拟能力明显提高,模拟风速的误差也显著减小。但不同分辨率下的风速频率和风向频率分布并无显著差别,不能很好地体现出风能特性。通过估算发电量发现,输入不同测风塔资料得到的发电量差异较大,说明在地形较为复杂的风电场,应多布设测风塔,以期得到较为准确的发电量结果。     

基于CFD和风洞实验对丘陵地形风资源分布的研究

随着新能源行业的深入发展,风电行业发展更为迅速,对于一个风电项目而言,研究其风资源分布特性尤为重要。中国内陆地形较为复杂,大部分为山地丘陵。受地形的影响,风资源分布特性较为复杂,评估较为困难。先建立余弦型的丘陵地形物理模型,分别采用CFD数值模拟、风洞实验2种方法对丘陵地形周围流场进行模拟仿真与实验测试,通过对丘陵迎风坡、背风坡特定参考点水平风速、垂直风速变化特征的分析,归纳总结了丘陵地形周围风资源分布特征,为丘陵地形下风能开发利用提供一定的参考。     

中尺度风资源数值模拟试验分析

应用中尺度数值模式模拟地区的风资源状况是一种比较先进的方法。该模拟成果对大范围区域风能资源的宏观评估和风电场宏观选址具有很好的参考价值。着重介绍了WRF(Weather Research and Forecast)数值模式模拟方法,并采用该模拟方法对近海风电场的风资源进行了模拟。     

风能资源评估系统搭建方法研究

复杂地形和低风速风电场风能资源评估过程中,在缺少实测数据的情况下寻找风能资源丰富的开发区域,对提高风电场的盈利能力具有重要的现实意义。本文针对风电场开发前期有效数据匮乏的情况,在传统风能资源评估系统的基础上,引入大气模式进行大范围计算获得中尺度计算结果,同时引入陆地卫星遥感资料处理技术,获得大范围高精度的地表粗糙度信息,结合计算流体动力学技术对中尺度数据进行降尺度,建立大气模式和计算流体动力学技术双核心的风能资源评估系统。本文所建立的先进风能资源评估系统可以满足复杂地形和低风速风电场风能资源评估的工程需要,从而拓宽了风能资源评估的途径。     

激光雷达在不同地形条件下进行风资源评估的适用性研究北大核心CSCD

为了验证WindCube激光雷达在不同地形和不同测量高度条件下替代测风塔评估风资源的可行性,文章采用WindCube激光雷达与测风塔在复杂山地、平原和沿海3种地形条件下的同步观测试验数据,对风速、风向、相对偏差和风廓线进行了对比分析。对比结果表明:WindCube测量高度越高,有效数据完整率越低,在90~120 m轮毂高度,有效数据完整率在90%以上,能满足风能资源评估要求;在复杂山地、平坦地形条件下,WindCube与测风塔风速相关系数达0.99以上,风向相关系数在0.85~0.90,两种仪器测得的10 min平均风速偏差在0.1 m/s以内,相对偏差在1%左右,WindCube可代替测风塔进行风能资源评估;沿海地形条件下,WindCube与测风塔风速相关系数达0.90以上,风向相关系数在0.90左右,WindCube与测风塔测得的10 min平均风速偏差较大,达0.5 m/s,相对偏差在10%左右,受下垫面影响,WindCube替代测风塔进行风能资源评估的可行性应根据项目实际情况进一步评估。     

测风塔选址对复杂地形风电场风资源评估的影响

为研究复杂地形条件下风电场测风塔的代表性及其对风资源评估的影响,以陕西省靖边县境内某风电场为例,选取3座测风塔资料,利用WindSim软件模拟分析了2011年风电场风能资源分布,并估算了风电场年发电量。结果表明,复杂地形风电场处测风塔数量较少时风资源评估结果的不确定性显著增加,而在考虑地形因素情况下测风塔数量增多,估算发电量更为准确。在地形较为复杂的风电场应根据地形条件布设适当数量测风塔,以得到风电场内较为精准的风资源分布,减少因测风塔位置选择而造成的风资源评估的不确定性。     

Variations of wind speed in time on Jeju Island,Korea

In order to clarify variability in wind energy over a long-term period of 30 years, an investigation was carried out on Jeju Island in South Korea, which has complex terrain. The selected areas for this study were Jeju, Seogwipo and Seongsan, which have wind data for 30 years from 1978 to 2007. The long-term wind data measured from automated synoptic observation system (ASOS) of meteorological observatories was analyzed in accordance with inter-annual, annual and diurnal time scales. Wind variations in various time scales were quantified by both the coefficient of variation and the range of variation. As a result, the yearly average wind speed tended to slightly decrease at the Jeju site, while the other two sites have random trends. The regional deviation for wind variations was significant on Jeju Island, which may result from its complex terrain. It was found that when wind data is measured and analyzed over a longer-term period, more reliable results can be obtained. Besides these, a statistically meaningful result will be presented in this paper.     

动态风工况下复杂地形风电场流场多尺度仿真

首先在秒级风速数据的基础上构建动态风速函数模拟真实风速工况,同时基于高程数据构建某真实复杂地形的三维结构图。基于格子玻尔兹曼方法并结合自适应格子排布,对复杂地形风电场非定常流场进行数值计算,得到该风电场的风资源分布。之后在典型位置布置2台2 MW风力发电机,考虑真实风力机叶片的动态旋转计算风力机及真实复杂地形在动态风工况下的流场。研究实际复杂地形和动态风速下风电场的风速分布及尾流结构演变规律。结果表明：该方法可实现对复杂地形在动态来流风速作用下的风资源分布预测,并考虑风力机小尺度尾流结构实现对真实风电场流场的多尺度仿真。     

Research of the wind energy resource distribution in the Baltic region

Governmental support and the availability of large unpopulated areas on the coasts of the Baltic countries make attractive the use of these lands for siting large wind power plants (WPP).Studies in the area of wind energy resource distribution are carried out by the IPE with collaboration with the VeU. The observations of wind speed were made using the measuring complex NRG LOGGER 9200 Symphonie.The results of long-term observations on the wind energy density fluctuations at heights of 10–60 m in the area on the Baltic Sea coast of Latvia are presented in the form of tables, bar charts and graphs.The wind speed distribution is analysed. The coefficients of approximating functions for two areas of different terrain types have been calculated, and extrapolation results for the distribution curves of wind speed and energy density obtained.The acoustic noise level distribution around a planned WPP has been modelled.     

复杂地形风电场微观选址实践探讨

  [目的]  相对于平坦地形风电场,复杂地形风电场内的风速、风向表现出显著的区域性差异,给机组选型、风机排布、发电量评估等工作带来了不小的挑战。旨在解决复杂地形风电场微观选址过程中可能出现的测风塔、等高线、限制因素等问题。  [方法]  基于收集到的风电场项目资料,结合作者工作经验,分别对其进行了详尽阐述,举例说明了限制因素对风电场发电量的显著影响。  [结果]  通过现场勘察,核实了测风塔确切位置、标记了场区范围内的限制因素位置和范围;利用3D矢量数据生成立体高程网格,结合等高线数值对比分析,检验了地形图中等高线值的准确性。  [结论]  准确的测风塔位置和较高质量的测风数据对风能资源评估有决定性作用;限制因素区域的标识,缩短了制定风机排布方案所需的时间,提高了工作效率;结合准确无误的等高线地形图可以较准确地模拟风电场及周边区域的风能资源情况,为投资者提供优质的评估成果。     

地形复杂的风电场资源评估误差分析方法

由于计算模型本身的限制,风能资源地图分析与应用程序(WAsP)不能准确模拟复杂地形中风的流动变化情况,用其评价复杂地形风电场的风能资源时存在一定误差.目前,主要采用RIX方法来评估WAsP在复杂地形中的风速预测误差,长期以来一直缺少根据风速预测误差来评估风电场发电量预测误差的有效方法.文章在RIX方法的基础上,对WAsP应用于复杂地形风电场发电量预测的误差进行了研究,结合工程实践提出了一种发电量误差评估方法;根据某风电场实际发电量数据对提出的评估方法进行了验证,证明其有效性和实用性.     

Front Cover

A major barrier to the deployment of wind energy in many regions of the world is a lack of reliable and detailed wind resource data. Availability of this data is essential for government and industry to identify wind power generation potential and to act on that knowledge. To overcome this barrier, The US National Renewable Energy Laboratory (NREL) has developed new methods to more accurately assess the wind resource and produce detailed high-resolution (1 km/sup 2/) wind maps for essentially anywhere in the world. These advancements were made possible by a combination of factors, such as the release of global climatic and terrain data sets that were not previously available along with the availability of advanced tools, including geographic information systems (GIS) software and computational modeling techniques. The NREL methodology for creating regional wind resource maps integrates the global terrain and climatic data sets, GIS technology, and analytical and computational modeling techniques. As a result, updated wind assessments can now be produced with much greater accuracy and detail than was previously possible.     

基于CFD的复杂地形风电机组机位微地形风资源数值模拟研究

  [目的]  在复杂地形进行风电机组建设时，机位点周围易形成高边坡地形，改变了风资源分布特征，影响机组发电量和安全性能，文章旨在研究高边坡地形的影响因素和预防其对机组的危害。  [方法]  基于STAR-CCM+软件平台对实际风电场机组高边坡地形进行了数值模拟，分析了立机位置选择、坡度、开挖深度等因素对机位处风资源参数的影响。  [结果]  结果表明:高边坡改变了原地形风的加速效应，产生大幅度的流体分离。当高边坡位于机组上风向时，机组下叶尖易产生较大的风切变，湍流强度超标，而高边坡在机组下风向时，机位处风资源参数则正常；高边坡的坡度大小对坡前立机风参数无显著影响；当下叶尖高度低于边坡高度时，机组位置下叶尖风速很小，切变值易超标。  [结论]  分析结果可为高边坡地形机组施工平台设计和塔筒高度选择提供参考。     

Site‐specific Design Optimization of Wind Turbines

This article reports results from a European project, where site characteristics were incorporated into the design process of wind turbines, to enable site‐specific design. Two wind turbines of different concept were investigated at six different sites comprising normal flat terrain, offshore and complex terrain wind farms. Design tools based on numerical optimization and aeroelastic calculations were combined with a cost model to allow optimization for minimum cost of energy. Different scenarios were optimized ranging from modifications of selected individual components to the complete design of a new wind turbine. Both annual energy yield and design‐determining loads depended on site characteristics, and this represented a potential for site‐specific design. The maximum variation in annual energy yield was 37% and the maximum variation in blade root fatigue loads was 62%. Optimized site‐specific designs showed reductions in cost of energy by up to 15% achieved from an increase in annual energy yield and a reduction in manufacturing costs. The greatest benefits were found at sites with low mean wind speed and low turbulence. Site‐specific design was not able to offset the intrinsic economic advantage of high‐wind‐speed sites. It was not possible to design a single wind turbine for all wind climates investigated, since the differences in the design loads were too large. Multiple‐site wind turbines should be designed for generic wind conditions, which cover wind parameters encountered at flat terrain sites with a high mean wind speed. Site‐specific wind turbines should be designed for low‐mean‐wind‐speed sites and complex terrain. Copyright © 2002 John Wiley & Sons, Ltd.