导流涵道对垂直轴水轮机性能影响的研究

Influence of duct on the performance of the vertical axis tidal turbine

垂直轴水轮机作为重要的潮流能捕获装置,相比于水平轴水轮机,它具有结构简单、适应任意水流等优点,但获能效率较低。为了增大垂直轴水轮机的获能效率,文章提出了一种导流涵道装置。采用CFD方法研究了其增速性能,并探究了水轮机在导流涵道下的输出扭矩特性,最后讨论了水轮机与导流涵道之间的间距对获能效率和转矩的影响。研究表明:导流涵道在一定程度上增大了来流的速度,涵道中心处速度可增大至原来的2倍。在导流涵道作用下,水轮机转矩脉动系数减小了0.474。水轮机与导流涵道的间距对效率与转矩产生了显著的影响,当间距为0.175倍水轮机直径时,其能源利用率达到最大,同时转矩系数在0.1倍直径时降至最小。

Vertical axis tital turbine served as an important ocean energy capturing device holds the advantages of being simple mechanism and being able to work in any direction of flow. however, it has a lower power coefficient. In order to increase the working efficiency of the turbine. A feasible duct device is put forward in this paper. By the method of CFD, we study the speed-up performance of the duct and the output torque characteristics of the turbine under diversion duct. Finally, the influence of the spacing between the turbine and the duct on the energy efficiency and torque is discussed. The results show that the duct largerly improves the flow velocity which can be increased two times the original than ever at the center of the duct. Furthermore, the torque ripple factor of the turbine reduces0.474.The gaps of the duct and the turbine obviously effects the hydro performance. When the spacing is 0.175 times length of the diameter of the turbine, the efficiency increases to maximum, at the same time, the torque ripple factor reached to the minmum in the case of 0.1 times of the turbine＇s diameter.