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基于风资源梯度自动观测系统,对柴达木盆地东缘地区风资源时间变化及空间分布特征进行了分析,结果表明:(1)研究区域具有较为丰富的风资源,3-25 m s-1之间风速累计时数平均超过6600h,也即275d,超过全年总时数的75%。从各梯度来看,随高度增加累积时数总体增加,小风时越往低层风速累计时数越大,大风时越往高层风速累计数越大;各分析站点中戈壁(GB)<3 m s-1风速时数相对最高,诺木洪(NMH)相对最低,≥3 m s-1风速时数正好相反;有效风速累计小时数小灶火(XZH)各梯度间差异不大,戈壁(GB)总体相对最小。(2)各梯度优势风速谱域基本处在3-9 m s-1范围,峰值风速出现在4-6 m s-1之间;除10 m梯度外,其余各梯度风速频率分布差异不大。相比较其它各层,10 m高度层小风出现频次较高,其余层6-12 m s-1的风速出现频次较高。(3)从不同方位风速及风功率密度情况来看,除戈壁(GB)外,总体优势风为西北风;除诺木洪外,总体风速差异不大。(4)随高度增加风速和风功率密度逐渐增大;但各站点之间差异较大。从逐月情况来看,小灶火(XZH)5-8月份平均风功率密度较大、诺木洪(NMH)和戈壁(GB)分别在4月和8月呈现出两个峰值、快尔玛(KEM)则在冬春季节风资源较丰富,而在夏季较贫乏;从逐小时情况来看,小灶火(XZH)和诺木洪(NMH)呈现出伴随地面温度升高风功率密度逐渐降低的趋势,戈壁(GB)和快尔玛(KEM)则正好相反。(5)各层风平均湍流强度为0.199,平均切变指数为0.075,自10-70m梯度湍流强度和切变指数总体自低层到高层逐渐降低。时间变化情况为,湍流强度与当地气温变化趋势基本一致,即高温对应高湍流,低温对应低湍流;切变指数变化趋势基本与湍流强度相反;各梯度间湍流强度自低层向高层递降,切变指数在10-30m层间最明显。各站点各层次湍流强度基本在0.1-0.25之间,属中等强度;切变指数各站点各层之间差异较大,总体小灶火(XZH)最小,诺木洪(NMH)最大,而且小灶火(XZH)底层为正切变,高层为负切变。期望通过本研究为该地区风电场布设及近地面层风能资源利用提供技术依据。
Based on the wind resource gradient automatic observation system, the time variation and spatial distribution characteristics of wind resources in the eastern Qaidam Basin were analyzed. The results show that: (1) The study area is rich in wind resources, 3-25 m s-1 The cumulative number of hours of wind speed averaged more than 6600h, or 275d, which exceeded 75% of the total number of hours in the year. From the perspective of each gradient, the cumulative hours increased with the increase of altitude. The smaller the winds, the greater the accumulated hours of lower wind speeds, and the greater the cumulative wind speed increased to the upper winds. In the analysis sites, the gobi (GB) <3 m s-1 was the highest, the NMH was the lowest, and the wind speed ≥3 m s-1 was the opposite; the effective wind speed accumulated hours was not significantly different between XZH gradients, Overall relatively small. (2) The wind speed spectrum of each gradient is basically in the range of 3-9 m s-1 and the peak wind speed is between 4-6 m s-1; except for a 10-m gradient, there is no significant difference in the frequency distribution of wind speeds . Compared with other layers, the winds at the 10 m level are more frequent and the wind speeds at the 6-12 m s-1 level are higher. (3) From the wind speed and wind power density in different directions, except for Gobi (GB), the overall dominant wind is northwest wind; except for Noxe Hong, there is not much difference in overall wind speed. (4) The wind speed and wind power density increase with altitude; however, there is a big difference between the stations. From the monthly situation, the mean wind power density of XZH from May to August was relatively large, while NMH and GB showed two peaks in April and August, respectively. (KEM), wind resources are richer in winter and spring and poorer in summer. From hour to hour, XZH and NMH show a gradual decrease in wind power density with increasing ground temperature The trend is the opposite between Gobi (GB) and KEM. (5) The average wind turbulence intensity of each layer was 0.199, and the average shear index was 0.075. From 10-70m, the gradient turbulence intensity and shear index decreased gradually from lower to higher layers. The time variation is that the trend of turbulence intensity is basically the same as that of the local temperature, that is, the high temperature corresponds to the high turbulence and the low temperature corresponds to the low turbulence. The trend of the shear index is basically opposite to that of the turbulent flow. The turbulence intensity decreases from the lower layer to the upper layer, The index is most noticeable in the 10-30m layer. The turbulence intensities at all levels of the stations are basically between 0.1 and 0.25, which are of moderate intensity. The shear index varies greatly between the various stations, with the smallest XZH and the NMH, (XZH) the bottom is positive shear, high shear negative shear. It is hoped that this study can provide technical basis for the wind farm layout in the region and the utilization of wind energy resources in the near-surface layer.