某燃气轮机第1级叶片气膜冷却换热特性分析  

ANALYSIS OF HEAT EXCHANGE BEHAVIOR CONCERNING AIR-FILM COOLING OF FIRST-STAGE BLADES OF ONE GAS TURBINE

作　　者：米珂[1] 褚贵宏[1] 仇璐珂[1] 王新军[2] 

机构地区：[1]西安热工研究院有限公司,陕西西安710032 [2]西安交通大学能源与动力工程学院,陕西西安710049

出　　处：《热力发电》2012年第6期19-23,共5页Thermal Power Generation

摘　　要：利用附加源项法,对某台燃气轮机开设多排气膜孔的第1级叶片外侧换热特性,包括叶片表面温度、气膜有效度和换热系数的分布进行计算及数值分析,并对叶栅换热特性进行了数值验证。结果表明,预测值Nu与试验值吻合较好;在压力面,叶片外表面温度平均可降低40%,平均气膜有效度约0.7;吸力面温度平均降低30%,平均气膜有效度约0.5。但是,在压力面20%相对弦长区域、前缘驻点和吸力面尾缘处的温度较高,气膜有效度较低。所给出的叶片外侧换热特性,可作为叶片内部结构的设计依据,通过在叶片内部前缘驻点和压力面20%相对弦长区域采用冲击冷却、增加吸力面尾缘冷却气体流量可降低该区域所受到的热负荷,从而使叶片能够均匀冷却。By using the NUMERCA software, the external heat exchange behavior of first - steage blades,such as the surface temperature of blades,the effectiveness of air film,and the distribution of heat exchange coefficient etc. ,boasting many rows of air film orifices opened on them of one gas tur- bine has been calculated and numerically analysed, and the heat exchange behavior of blade cascade be- ing numerically verified. It shows that the predicted value Nu tallies well with the tested value. On the pressurized area, the surface temperature of blades can be reduced by 40 % on the average,the average effectiveness of air film being about 0.7;on the suction area, the temperature reduced 30% on the aver- age, the average effectiveness of air film being about 0.5 ; but, the temperature on cord - length region relative to 20% of the pressurized area, at standing points on front edge and on the tail edge of the suction area was higher , and the effectiveness of air film being lower . The given external behavior ofblades can be used as design basis of blades＇ internal structure;at standing point on front edge inside the blades and on the cord- length rigion relative to 20% of the suction area,impact cooling has to be used, increasing the flow rate of cooling air at tail edge of the suction area, reducing thermal load on said region, so as to make the blades to be uniformly cooled.

关 键 词：燃气轮机 第1级叶片 气膜冷却 换热 压力面 吸力面 

分 类 号：TK471[动力工程及工程热物理—动力机械及工程]