海洋温差能发电透平设计及性能影响

 通过对海洋温差能发电向心透平气动部分进行设计，对其气动性能及喷嘴的影响进行模拟研究。采用经验参数和遗传算法对其进行一维参数设计，并通过三维造型得到透平气动模型。采用计算流体动力学（CFD）技术对透平的三维流场和性能进行了数值模拟。结果表明，在设计工况下透平的气动效率达到86.5%。在此基础上，对设计工况下的喷嘴-叶轮径向间隙和喷嘴叶片安装角进行分析，得到喷嘴-叶轮相对径向间隙为0.04左右，可变喷嘴安装角约为37°时，透平的效率最高。因此，在设计工况下，可通过对喷嘴-叶轮径向间隙和喷嘴安装角进行微调来得到更高的透平效率；在非设计工况下，可采用可调喷嘴来适应不同工况下的流动，使得透平在不同工况下均有较好的工作性能。

Design and performance of turbine in ocean thermal energy conversion

In order to improve the cycle efficiency of the ocean thermal energy conversion (OTEC), the performance of a radial inflow turbine is studied. Based on the 1-D thermodynamic design of the turbine with the main parameters determined by experience and modified by a genetic algorithm, an aerodynamic model of the turbine is built through the 3-D design of the volute, the nozzle and the impeller. The performance of the turbine under the design condition is studied by the computational fluid dynamics (CFD) and the numerical results show that the turbine efficiency is 86.5%. Finally, it is shown that the turbine has a good performance when the nozzle-impeller relative radial clearance is 0.04 and the nozzle stagger installation is about 37°. Therefore, the nozzle-impeller radial clearance and the nozzle installation angle can be fine-adjusted to obtain a higher turbine efficiency under the design condition; and under the non-design conditions. An adjustable nozzle mechanism can be used under the off-design conditions to put the turbine in a good working state under various working conditions.