挡流板对垂直轴风力机性能影响的试验研究与分析

Experimental study and analysis of the influence of deflector on the performance of vertical axis wind turbine

在风力机前方安装挡流板可提高H型垂直轴风力机的发电功率,但目前缺少对该结构装置的全面系统研究,且评估安装挡流板时所使用的风能利用系数C_(P)的计算方法并不恰当,以至于某些计算结果突破贝兹极限,导致概念混淆。文章通过对挡流板安装位置及安装角度进行测试,获取了不同位置的风力发电功率随风轮转速的变化关系。结果表明:在一定距离范围内,挡流板与风轮有一最佳距离,挡流板远离风轮时,提高风速的效果差,挡流板距离风轮越近对来流风干扰变大,输出功率反而降低;挡流板的最佳安装角度为90°,安装角小于或者大于90°时,风速变化平缓,输出功率增长减弱,失去聚风作用。考虑到挡流板聚风后叶轮前的风场不均匀,在计算C_(P)时不能取某一个风速值或用平均值代入其定义式,文章提出了采用平均风动能的统计方法计算C_(P),计算结果表明,增加挡流板可以提高输出功率,但不一定能增加C_(P)值。

Installing deflector in front of the wind turbine can improve the power of H-type vertical axis wind turbine.There is no comprehensive system research on this kind of structural device.And the calculation method of C_(P)used in the evaluation is not appropriate.Some calculation results break through the Bates limit,leading to conceptual confusion.Through the experimental test of installation position and angle of the deflector,curve of power changing with the speed of the wind turbine is obtained.The results show that,within a certain range,the deflector has the best distance from the wind turbine.Far away from the wind turbine,the effect of improving the wind speed is poor.The closer it is,the greater the interference to the incoming wind is,lower theoutput power.The best installation angle is 90°.As the installation angle increases or decreases at 90°,the speed changes smoothly,and the output power growth weakens gradually,and gradually loses the effect of gathering wind.In this paper,the statistical method of average wind energy isproposed to calculate C_(P).The results show that the output power can be increased by increasing the deflector,but not necessarily the C_(P)value.