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用数值模拟方法,对北京某城市商业综合体内部公共空间空调工况热环境进行了研究,分析了各层不同送风比例下,综合体内部公共空间纵截面温度分布情况和人员活动区域内的温度分布情况。通过比较,确定了满足综合体内部公共空间各层热舒适要求的空调送风方案。数值模拟结果表明,对于城市商业综合体内部公共空间采用各层均匀送风,顶层与公共空间相连的走廊区域温度在夏季不能满足热舒适要求,适当减少内部公共空间下层的送回风量,增加至顶层,在冬夏工况下均可有效改善内部公共空间热环境,增加舒适度,有效解决顶层走廊温度偏高及温度不均等问题。 相似文献
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利用列车的活塞效应,将隧道内的空气通过活塞竖井与外界交换(当室外温度低于隧道温度),是一项有效利用自然能源的节能措施。分析当前地铁隧道中活塞竖井通风不足的原因,提出在地铁隧道区间设置帘幕提高活塞效应的构想。为了验证帘幕对风井通风量的影响效果,利用CFD技术模拟典型工况条件下帘幕安装前后活塞风速度及流量差异,并将没有设置帘幕的模拟结果与实测数据做了对比。对设置帘幕后典型隧道模拟结果表明,列车以12.5 m/s匀速运行时,活塞竖井进风量和排出风量是帘幕设置前的2.49与7.74倍。在模拟工况条件下,仅靠活塞作用基本可以满足规范对隧道区间的温度要求,而无需再利用机械通风或空调等手段冷却隧道。 相似文献
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以某大空间实验基地为研究对象,针对喷口送风和柱状下送风两种分层空调的热环境及供冷量进行了实测研究.研究结果表明:因喷口送风空调区较大,在夏季室外气象参数基本相同的两种室外气象条件下,喷口送风空调系统供冷量比柱状下送风空调系统的供冷量分别高出20.8%、24.4%,且喷口送风空调系统抗干扰能力较柱状下送风强;喷口送风时工作区温度均匀性好于柱状下送风,头足温差较小,但其工作区风速超过标准,而柱状下送风时工作区风速则符合环境设计要求;两种不同送风量下喷口送风时吹风感指数分别为15.64%、11.23%,而柱状下送风时吹风感指数分别为4.17%、2.40%,柱状下送风要明显优于喷口送风.故从节能及热舒适性角度综合考虑,单侧回风的大空间建筑应尽可能采用柱状下送风分层空调,而对于干扰比较大,空调场地较小,无法布置柱状下送风口的场合,则选取喷口送风较好. 相似文献
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以某工业车间为研究对象,利用Airpak软件模拟了车间原置换通风方式下的流场分布,发现在原气流组织方式设计负荷下虽然可保证室内热舒适,但送风负荷偏大,导致夏季温度偏低,冬季温度偏高;并且工作区的气流风速偏高,吹风感较严重。对原气流组织方式进行了改进及优化,改进后的气流组织方式减小了非工作区的冷负荷,增大了工作区的送风冷负荷,降低了车间的总冷负荷,并对改进后的方式进行了数值模拟。结果表明:在改进后的气流组织方式下,车间工作区的温度冬季、夏季均达到舒适性要求,且整体送风冷负荷降低了28%,送风热负荷降低了33%,改善了热舒适,实现了节能。 相似文献
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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. 相似文献
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风电场风切变指数研究 总被引:1,自引:0,他引:1
根据山东某风电场实测资料,对风电场逐月、逐时、不同风速下的风切变指数进行研究并探究风切变指数不同取值对风电场轮毂高度处风资源的影响。在分析轮毂高度风资源时,建议采用高差较小的高度处风速根据综合风切变指数进行推导。 相似文献
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对陕西省宝鸡市陇县金润河北镇风电场气象条件、风功率密度、平均风速、主导风向等风能参数进行分析评价。结果表明,测风塔100 m高度月平均风速、月平均风功率密度最大均出现在4月,最小均出现在8月;测风塔100 m高度主导风向为SSW(南西南),主要风能方向为SSW(南西南),风电场风功率密度等级为1级。风电场安装20台2500 kW的风电机组,装机容量50 MW,年设计发电量1.33485×108 kW·h,年出厂电量9.5426×107 kW·h。结果可为其他风电场选址和发电量估算提供参考。 相似文献
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过分析我国内陆河北省张北县和吉林地区风电场内的风速廓线变化特性发现,各高度间风速的差异分布大体相同:各高度间风速差异由夜间到白天逐渐缩小,在中午达到最小,由白天到夜间逐渐增大,并且在各个阶段又相对稳定,即在日出后由地面向上的热量输送逐渐增强,湍流加强,各层间的风速差异减少,并迅速趋于稳定,直至日落湍流减弱。各层间的风速差异迅速增大,并趋于稳定。这一规律的发现对解释涡轮高度不同时间、相同风速条件下风机出力不同及风电功率建模有重要意义。 相似文献
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Maximization of the annual energy production of wind power plants by optimization of layout and yaw‐based wake control 下载免费PDF全文
This paper presents a wind plant modeling and optimization tool that enables the maximization of wind plant annual energy production (AEP) using yaw‐based wake steering control and layout changes. The tool is an extension of a wake engineering model describing the steady‐state effects of yaw on wake velocity profiles and power productions of wind turbines in a wind plant. To make predictions of a wind plant's AEP, necessary extensions of the original wake model include coupling it with a detailed rotor model and a control policy for turbine blade pitch and rotor speed. This enables the prediction of power production with wake effects throughout a range of wind speeds. We use the tool to perform an example optimization study on a wind plant based on the Princess Amalia Wind Park. In this case study, combined optimization of layout and wake steering control increases AEP by 5%. The power gains from wake steering control are highest for region 1.5 inflow wind speeds, and they continue to be present to some extent for the above‐rated inflow wind speeds. The results show that layout optimization and wake steering are complementary because significant AEP improvements can be achieved with wake steering in a wind plant layout that is already optimized to reduce wake losses. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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风切变指数在风电场风资源评估中的应用 总被引:4,自引:0,他引:4
以内蒙古地区3座70m高测风塔连续2年的实测数据来分析风切变指数的变化,结果表明:1)不同高度梯度的风切变指数受地面粗糙度及周围地形地貌的影响较大。2)计算相邻高度的风速时,采用相邻高度间的风切变指数计算得到的结果较好;计算相差较大的高度间风速时,采用拟合曲线得到的风切变指数计算得到的结果较好。3)利用3~25m/s的风切变指数计算各月风速及年均风速结果都与实测值最接近;而利用全部风速数据的风切变指数计算统计各月风速往往比实测值偏大;利用3~25m/s拟合曲线得到的风切变指数统计各月风速比实测值偏小。 相似文献
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Henry Louie 《风能》2014,17(6):793-810
Studies have shown that the unpredictability and variability of wind power is reduced in systems with large numbers of geographically diverse wind plants. These effects are caused by the decreased correlation of power output between wind plants as their separation and diversity in terrain increases. One way that system operators have increased geographic diversity is by enlarging balancing areas through the physical or administrative connection of adjacent systems. This strategy can be extended from the regional level to the transcontinental level. As such, it is important to study the correlation and statistical characteristics of aggregate wind power between large, distant systems. This paper analyzes multi‐year historical data from four North American system operators—Bonneville Power Administration, Electric Reliability Council of Texas, Midwest Independent Transmission System Operator and PJM—to see how effective transcontinental interconnection of systems is at enabling wind plant integration. The effects of separation and timescale on correlations of instantaneous and hourly variations are analyzed. The analysis is complemented by a study of a hypothetical transcontinental connection of the systems across yearly, monthly, daily and hourly timescales. The results show that correlations between large systems exhibit similar characteristics as the correlations between individual wind plants, but are somewhat larger in magnitude. The transcontinental system exhibits a close to normal distribution of power output and decreased variability, but there is still appreciable and statistically significant correlation at the longer timescales driven by seasonal and diurnal forcing, as well as synoptic weather systems. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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风切变对大直径风力机风轮输出功率影响的初探 总被引:1,自引:0,他引:1
以风切变幂指数为0.14的风廓线模型进行了风轮输出功率计算,并与以风轮中心风速计算风轮功率进行了对比分析,指出风切变对风轮输出功率的影响不容忽视。 相似文献
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提出风电场建模方法建立风电场随机模型,对风电场运行特性进行仿真,为实现大规模风力发电的可预测、可控制目标服务。通过对风电场等值模型与详细模型的仿真比较,验证建模方法的合理性,并得出在研究风电场动态特性及其对电网影响时应考虑风速、风向的随机波动建立风电场模型。 相似文献
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内蒙古地区风资源评估与风场特征风速的推导 总被引:1,自引:0,他引:1
对内蒙古二十四个地区的风能资源进行评估,得到风谱图.首先提出了利用WAsP软件对1998年至2008年期间内蒙古二十四地区的风资源资料中的基础进行分析;然后利用风速威布尔分布函数和风力发电机组输出功率的威布尔的概率密度函数,求两个函数的极值,推导出切入风速和额定风速的公式.最后以内蒙古六个地区为例,计算不同风资源条件下的切入风速和额定风速. 相似文献