扩压风道型建筑风能利用的探讨

根据扩散型风力机的原理,构想了一种新型风能利用建筑型式--扩压风道型建筑.探讨了扩压风道型建筑的特点,并对影响其风能利用的扩散角α、建筑尺寸、来流偏向角β等因素进行了数值模拟.通过分析可以看出,扩压风道型建筑能够强化风速及风能密度,是一种有效的风能集结建筑.     

风能及其利用

风能利用是一门综合性科学,涉及到空气动力学、电机、结构、材料、控制、气象等学科,内容很丰富。这里仅介绍风能利用中应了解的几个主要问题。风的形成及其特性风是一种自然现象,它是由太阳辐射热引起的。从太阳传到地球上的能量中,大约有2%的能量转变成风能。地球上全部风能估计约为2×10~(17)千瓦,其中可利用的约为2×10~(10)千瓦。这个能量是相当大的。     

扩散体建筑风能利用的风洞试验

扩散体建筑是用来汇集风能的建筑形式.通过风洞试验,研究了3种具有不同截面形状的扩散体建筑对增强风速及强化风能的效果.试验结果表明:截面形状为肾形的建筑其风力集结效果最好.可利用风能的高度范围较大;截面形状为椭圆形和扩压风道形的建筑也具有良好的效果.通过对试验数据与模拟数据比较分析可见,风洞试验得到的数据与模拟结果较为吻合,既验证了数值模拟结果的准确性,又为建筑环境中风能利用的研究奠定了试验基础.     

风能利用技术讲座(五)风力机的安装使用及利用前景

１风力机安装地址的选择为了充分利用风能资源，选择好风力机的安装地点是至关重要的。选择安装地点应从３个方面考虑：一是风能资源与气象条件；二是地形地貌；三是建筑物。１．１风力资源与气象条件（１）选择风能比较丰富的地域。对于大、中型风力机而言，当地年平均风速应大于５m／s；对于小型风力机而言，当地年平均风速应大于３m／s，一年内有效风速时间应大于２０００h。（２）一年四季有相对比较稳定的风向，风向变化不宜太频繁。（３）要选择强风暴、大雪、雷电、沙尘暴、盐雾等较少发生的地区。１．２地形地貌（１）当风力机安装…     

叶片实度对建筑增强型垂直轴风力机气动性能的影响

采用数值模拟的方法对建筑环境中具有不同实度的建筑增强型垂直轴风力机进行模拟。对NACA0021翼型作为叶片截面的三叶片原始直线翼垂直轴风力机周围流场进行数值模拟并与实验值进行比较,且进行了网格无关性验证,验证了计算模型的合理。结果表明:随实度的增加,建筑增强型风力机气动性能与自启动性能得到大幅改善,风力机平均力矩增大,风能利用率最大提升至4.47倍,但其载荷波动也非常剧烈,对结构安全性与可靠性提出更高的要求。实度过小则无法有效地捕获风能;实度过大则叶片之间的干扰增加,最大风能利用率增幅可降低至3.11倍。     

风能利用可望成为我国21世纪的新兴产业

介绍了发达国家风力机工业发展概况及风力机制造业的技术特点,介绍了国内的现状,讨论了国产化与产业化的可能性,分析了经济效益与社会效益。     

复杂地形条件下应用CFD技术进行风能资源评估应用分析

本文介绍了中国云南某地形极其复杂的风电项目不同测风塔之间进行模拟外推并与实际数据进行交叉验证的例子。同时,结合多测风塔综合技术,在不同权重情况下进行多塔综合,并对风流评估进行改进。通过对不同测风塔实际数据的验证,再次确认了计算流体力学技术在复杂环境与复杂山地条件下的有效性及可靠性。     

我国风能利用现状

我国有丰富的风能资源,风能总储量为３２－２６亿ｋＷ,实际可开发的风能储量为２－５３亿ｋＷ。风能是我国目前技术最成熟、最有开发利用前景的一种新能源。风能利用的主要方式有风力发电、风力提水、风帆助航等,本文就我国风能利用的现状向读者作一介绍。１风力提水我国适合风力提水的区域辽阔,作业众多因此发展风力提水是弥补当前农村、牧区能源不足的有效途径之一。我国东南沿海、辽东和山东半岛以及海上岛屿等地区,风能资源丰富,地表水源也丰富,是我国以抽提地表水为主的最佳风力提水区;内蒙、青海、甘肃和新疆北部河谷地带,风…     

趣谈风能利用

一帆风顺、风调雨顺、风和日丽、狂风暴雨、风雨同舟、微风荡漾……人们每天都在谈论风。风是我们最常见的自然现象之一。那么,风是怎样产生的呢?太阳和风     

Wind energy utilization in a house in Izmir,Turkey

The aim of this research is to cover the energy needs of a house, which does not have any other energy source, by using wind power. A house in Izmir, where the wind velocity values of 1998 are known, and five different wind turbines were studied. The daily energy use of the house was determined and batteries were used to obtain a continuous energy. For each wind turbine the number of batteries needed for continuous energy was calculated and a financial analysis of each turbine and battery system was carried out. Copyright © 2001 John Wiley & Sons, Ltd.     

论我国风能资源开发利用法律制度

阐述了我国风能资源以及开发利用现状;指出了造成我国风能资源开发利用率相对较低和20世纪90年代中期以前风能产业发展徘徊不前的三大主要问题;重点分析介绍了我国风能资源调查制度、总量目标和发展规划制度、产业指导与技术支持制度、上网电价及费用分摊制度、专项资金制度和风电开发环境保护制度等六大法律制度。文章运用了实证研究法与案例分析法,注重理论与实践相结合,为有志于风能产业发展的企业、部门和行业提供政策和法律制度的参考。     

A review of wind energy activities in Japan

By 2012, Japan must cut down on its annual emissions of greenhouse gases by 6% from 1990 levels. However, greenhouse emissions increased by 6.4% in 2006. More effective responses to reduce greenhouse gases are required. Attention is currently focused on increasing the use of renewable energy, and wind energy has received a lot of attention. The national target for wind power capacity in the year 2010 is 3000 MW; however, there are many barriers to the development of wind energy. Japan's climate differs from that of the European Union countries. It often experiences typhoons and lightning strikes because of its meteorological characteristics. Wind has a stronger turbulence level due to the complex terrain. Furthermore, power fluctuation of wind causes power system problems because of issues related to the grid connection. Many endeavours have been made to find the best solutions for these problems. This paper reviews the wind energy activities in Japan, including wind resources, market trends, environment, prospects and research and development. Copyright © 2009 John Wiley & Sons, Ltd.     

Thermodynamic analysis of wind energy

Wind energy is assessed thermodynamically, from resource and technology perspectives. The thermodynamic characteristics of wind are considered. Wind speed is affected by air temperature and pressure and has an effect on wind turbine performance, based on wind chill effect and Bernoulli's equation. The wind chill effect leads to temperature differences that suggest enthalpy and entropy components must be considered in a thermodynamic analysis. The wind pressure effect based on Bernoulli's equation affects the entropy of wind. These components have not previously been considered in evaluations of wind turbine efficiency for electricity generation. A new efficiency formula for wind energy systems is described, which provides important information about the system. It is seen that average differences between energy and exergy efficiencies are approximately 40% at low wind speeds and up to approximately 55% at high wind speeds. Copyright © 2005 John Wiley & Sons, Ltd.     

Sensitivity of southern California wind energy to turbine characteristics

Using output from a high‐resolution meteorological simulation, we evaluate the sensitivity of southern California wind energy generation to variations in key characteristics of current wind turbines. These characteristics include hub height, rotor diameter and rated power, and depend on turbine make and model. They shape the turbine's power curve and thus have large implications for the energy generation capacity of wind farms. For each characteristic, we find complex and substantial geographical variations in the sensitivity of energy generation. However, the sensitivity associated with each characteristic can be predicted by a single corresponding climate statistic, greatly simplifying understanding of the relationship between climate and turbine optimization for energy production. In the case of the sensitivity to rotor diameter, the change in energy output per unit change in rotor diameter at any location is directly proportional to the weighted average wind speed between the cut‐in speed and the rated speed. The sensitivity to rated power variations is likewise captured by the percent of the wind speed distribution between the turbines rated and cut‐out speeds. Finally, the sensitivity to hub height is proportional to lower atmospheric wind shear. Using a wind turbine component cost model, we also evaluate energy output increase per dollar investment in each turbine characteristic. We find that rotor diameter increases typically provide a much larger wind energy boost per dollar invested, although there are some zones where investment in the other two characteristics is competitive. Our study underscores the need for joint analysis of regional climate, turbine engineering and economic modeling to optimize wind energy production. Copyright © 2012 John Wiley & Sons, Ltd.     

浓缩风能型风力发电机迎风调向MCU控制系统

浓缩风能型风力发电机具有起动风速低、发电时间长、风能利用率高等优点。根据浓缩风能型风力发电机的形体结构,设计了基于89C51单片机的迎风自动控制系统。整个系统可在风向变化超过-15～15°时自动迎风,达到了设计要求,为浓缩风能型风力发电机组向中、大型并网发电机组发展奠定了基础。     

国外风能利用和研制技术新进展

风能作为可再生能源之一，一直是开发和利用的重点。在新世纪，风能在国民经济和新能源发展中占有重要地位，其利用和开发技术也有新的发展。     

Investigations of a building‐integrated ducted wind turbine module

So far, wind energy has not played a major role in the group of technologies for embedded generation in the built environment. However, the wind flow around conventional tall buildings generates differential pressures, which may cause an enhanced mass flow through a building‐integrated turbine. As a first step, a prototype of a small‐scale ducted wind turbine has been developed and tested, which seems to be feasible for integration into the leading roof edge of such a building. Here an experimental and numerical investigation of the flow through building‐integrated ducting is presented. Pressure and wind speed measurements have been carried out on a wind tunnel model at different angles of incident wind, and different duct configurations have been tested. It was confirmed that wind speeds up to 30% higher than in the approaching freestream may be induced in the duct, and good performance was obtained for angles of incident wind up to ±60°. The experimental work proceeded in parallel with computational fluid dynamics (CFD) modelling. The geometry of the system was difficult to represent to the required level of accuracy, and modelling was restricted to a few simple cases, for which the flow field in the building‐integrated duct was compared with experimental results. Generally good agreement was obtained, indicating that CFD techniques could play a major role in the design process. Predicted power of the proposed device suggests that it will compare favourably with conventional small wind turbines and photovoltaics in an urban environment. Copyright © 2002 John Wiley & Sons, Ltd.     

A review on development of offshore wind energy conversion system

Wind energy conversion system, aiming to convert mechanical energy of air flow into electrical energy has been widely concerned in recent decades. According to the installation sites, the wind energy conversion system can be divided into land-based wind conversion system and offshore wind energy conversion (OWEC) system. Compared to land-based wind energy technology, although OWEC started later, it has attracted more attentions due to its significant advantages in sufficient wind energy, low wind shear, high power output and low land occupancy rate. In this paper, the principle of wind energy conversion and the development status of offshore wind power in the world are briefly introduced at first. And then, the advantages and disadvantages of several offshore wind energy device (OWED), such as horizontal axis OWED, vertical axis OWED and cross axis OWED are compared. Subsequently, several major constraints, such as complex marine environment, deep-sea power transmission and expensive cost of equipment installation faced by offshore wind conversion technology are presented and comprehensively analysed. Finally, based on the summary and analysis of some emerging technologies and the current situation of offshore wind energy utilization, the development trend of offshore wind power is envisioned. In the future, it is expected to witness multi-energy complementary, key component optimization and intelligent control strategy for smooth energy generation of offshore wind power systems.     

Operating experience from the ehecatl wind turbines

This paper presents a summary of the mechanical features and the medium term operating experience from three small horizontal axis wind energy conversion systems covering a range of 500 to 5000 Watt, intented for rural and isolated communities. These turbines have a new regulator which reduces gyroscopic loads, is easy to adjust and could be manufactured stronger and in smaller sizes than the conventional tail vanes. It is concluded that is feasible to build cheaps and reliable wind turbine generators with an acceptable efficiency employing common-use elements, but is needed a careful and optimized design.