陆/海风电场群对局地湍流和风切变影响差异初步分析

Preliminary Analysis on the Influence Difference of the Inland/Offshore Wind Farm Group on Local Turbulence Intensity and Wind Shear Exponent

风电场存在着明显的局地气候效应,但陆/海两种不同类型风电场是否存在局地风环境效应的明显差异?以河北尚义陆地风电场和江苏如东海上风电场为例,利用风电场周边气象站及测风塔典型年份观测资料,开展了陆/海风电场对湍流强度(TI)和风切变指数(WSE)的影响差异初步分析研究。研究结果表明:陆/海风电场对TI和WSE会产生显著影响;其中,陆/海风电场对TI均为增强效应,建设后年均TI分别增加31%和37%,最大增幅分别发生在春季(47%)和冬季(49%);影响差异主要为陆地风电场TI增幅在高层明显大于低层,夜间大于白天,而海上风电场不同高度TI增幅及日变化则较为平稳;陆/海风电场对WSE影响差异显著,陆地风电场建设后WSE白天增加、夜晚降低,日变化明显减小,年均降低8%,最大降幅发生在秋季(12%);海上风电场建设后WSE白天、夜晚均明显增加,年均增加24%,最大增幅发生在春季(37%)。

Wind farms have obvious impact on the local climate.However,whether there exist obvious differences in environmental effects of local wind between the inland and offshore wind farms still need to be explored.Based on the inland wind farm data from Shangyi,Hebei Province and offshore wind farms in Rudong,Jiangsu Province and the data of meteorological observation and wind gradient tower around wind farm the influence difference of the inland and offshore wind farms on local wind environment,turbulence intensity(TI)and wind shear exponent(WSE)are preliminarily analyzed.The results show that the inland and offshore wind farms have significant effects on TI and WSE.The constructed inland and offshore wind farms have an enhancement effect on TI,and the average annual TI increased by 31%and 37%,respectively.The largest increment occurred in spring(47%)and winter(49%)in inland and offshore wind farms respectively.Moreover,the TI increasing range of high-level was greater than that in low-level,and greater at night than in day in inland wind,while the TI increasing range was relatively stable at different heights and diurnal variation in offshore wind farms.In terms of WSE,the constructed inland and offshore wind farms have significant differences in their influences on WSE.The WSE increased during the day and decreased at night,and the diurnal variation was significantly reduced with the average annual WSE decreased by 8%,and the largest decline in WSE in autumn(12%)in the inland wind farms.By contrast,the WSE increased obviously during both day and night with average annual WSE increased by 24%,and the largest rise seen in spring(37%)in offshore wind farms.