燃机透平静叶尾缘柱肋通道内的汽雾/空气冷却流动与换热特性数值研究  

Numerical Investigation for Flow and Heat Transfer Characteristics of Air and Air/Mist Cooling in Gas Turbine Stator Trail Edge Path

作　　者：周子杰[1] 王新军[1] 费昕阳 

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2016年第11期21-27,共7页Journal of Xi'an Jiaotong University

摘　　要：基于通过提高燃气进口温度来提升燃气轮机热效率和增加出力的思想,采用ANSYS-CFX商用软件对模化的燃气轮机透平静叶尾缘楔形柱肋冷却通道中流动与换热特性进行了数值模拟,对比研究了冷却工质为空气和汽雾/空气时的冷却性能,以及不同的雷诺数和雾滴初始直径下雾滴在流动过程中的分布、努塞尔数、摩擦系数以及热力综合效率的变化情况。研究表明:雾滴初始直径越大、雷诺数越大,雾滴的流动距离越长;相同雷诺数条件下,相对于空气冷却,加入不同初始直径的雾滴可提高通道底面平均努塞尔数,换热效果强化越明显;底面平均努塞尔数的增幅与雷诺数和雾滴初始直径有关,为了达到最佳冷却效果,应考虑雾滴蒸发吸热和扰流两方面的影响;在冷却空气中加入雾滴后流动摩擦系数变化较小,综合考虑换热性能与流动阻力,加入汽雾可使热力综合效率最高提高26%。该结果可为燃机设计提供参考。Increasing the turbine inlet temperature is a feasible method to improve the cycle thermal efficiency and power output of a gas turbine. The heat transfer and flow characteristics of air and air/mist cooling in the trail edge path of a gas turbine stator are numerically investigated with ANSYS-CFX. The simulations for different working fluids （air and air/mist） are carried out to find their cooling performance difference. The changes of mist distribution, Nusselt number, flow friction factor and thermodynamic efficiency are analyzed in the cases of different Reynolds number and different initial diameter of mist. The results show that the mist flow distance goes up when Reynolds number and mist initial diameter increase. At the same Reynolds number, the bottom averaged Nusselt number increases when spraying mist with different initial diameter into cooling air. The enhancement of the bottom averaged Nusselt number is related to Reynolds number and the initial mist diameter. To reach the highest cooling performance, the evaporating and disturbance effects of mist ought to be taken into consideration. Spraying mist into cooling air slightly affects the friction factor, but the increase of thermodynamic efficiency can reach up to 26% considering both heat transfer and flow friction.

关 键 词：燃气轮机 汽雾/空气冷却 冷却性能 数值模拟 

分 类 号：TK47[动力工程及工程热物理—动力机械及工程]