气膜冷却共轭传热性能对CMAS颗粒沉积规律影响研究  

Study on Effect of Conjugate Heat Transfer of Film Cooling on CMAS Particle Deposition

作　　者：陈小虎 刘勋[2] 王玉璋[1] 翁史烈[1] CHEN Xiao-hu;LIU Xun;WANG Yu-zhang;WENG Shi-lie(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai,China,Post Code:200240;Harbin Marine Boiler&Furbine Kesearch Institute,Harbin,China,Post Code:150078)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240 [2]哈尔滨船舶锅炉涡轮机研究所,黑龙江哈尔滨150078

出　　处：《热能动力工程》2021年第10期1-10,共10页Journal of Engineering for Thermal Energy and Power

基　　金：国家科技重大专项(2017-Ⅰ-0007-0008)。

摘　　要：基于颗粒速度、温度、粘度和组分之间的函数关系以及与壁面的碰撞、反弹、粘附和去除机制,建立了CMAS(CaO-MgO-Al;O;-SiO;)颗粒在涡轮叶片表面沉积的数学模型,研究了不同吹风比0≤M≤2和粒径下气膜冷却共轭传热性能对气膜冷却有效度、CMAS沉积效率和沉积规律的影响规律。结果表明:当吹风比为0≤M≤2时考虑共轭传热的平均气膜冷却有效度随吹风比非线性增大,M>1.5时气膜孔下游出现明显的对转涡对和冷却剂射流分离;气膜孔出口存在被CMAS堵塞的潜在风险,小吹风比时气膜孔被严重堵塞,大吹风比时气膜孔间以及下游气膜覆盖间隙处形成典型的扇形周期性沉积"犁沟",CMAS沉积效率随吹风比的增大而减小;分析工况下,随着粒径增大沉积效率显著降低,粒径为4μm时沉积效率最大,可达28.5%。Gas turbine cannot operate in completely pure environment.Particulate matter in air and impure fuel will form CaO-MgO-Al;O;-SiO;(CMAS) particles in the combustion chamber during service.CMAS deposition on the surface of turbine blade will deteriorate the cooling performance of the film cooling and shorten the service life of gas turbine.Based on the functional relationship between particle velocity, temperature, viscosity and components and the mechanism of collision, rebound, adhesion and removal with the wall, the mathematical models for the CMAS deposition were established.The effect of conjugate heat transfer performance of film cooling on the CMAS deposition efficiency and performance under different blowing ratio 0≤M≤2,and particle sizes were studied.The results show that the average film cooling efficiency under conjugate heat transfer increases nonlinearly with the increase of blowing ratio at 0≤M≤2,and obvious counter-rotating vortexes(CRVP) and coolant jet separation appear downstream of film holes when.The film holes may be the starting point of particles deposition on the vane.The film holes are seriously blocked at low blowing ratio, and typical fan-shaped periodic deposition "furrows" are formed between film holes and downstream film coverage gaps under high blowing ratios.The deposition efficiency decreased with the increase of blowing ratio.The maximum deposition efficiency of particles with a size of 4 μm on the wall is 28.5%,and the deposition efficiency decreases significantly with the increase of particle size.

关 键 词：涡轮叶片 CMAS沉积 共轭传热 沉积特性 

分 类 号：TK124[动力工程及工程热物理—工程热物理]