压气机不同运行工况下湿压缩性能分析  

Analysis of the Wet Compression Performance of a Compressor Under Different Operating Conditions

作　　者：郑洪涛[1] 陈佩[1] 

机构地区：[1]哈尔滨工程大学动力与能源工程学院,黑龙江哈尔滨150001

出　　处：《热能动力工程》2011年第2期162-167,251,共6页Journal of Engineering for Thermal Energy and Power

摘　　要：湿压缩技术能够有效提高燃气轮机输出功,降低燃气轮机对大气环境的依赖程度。该技术对压气机的影响因素非常复杂,压气机的运行工况对湿压缩效果的影响甚大。本研究采用CFX软件对某型三级轴流压气机在不同工况下的干、湿压缩过程进行三维数值模拟。结果表明:压比不变的情况下,高转速时压气机近失速边界处质量流量增加,低转速时质量流量下降;转速不变的情况下,压比降低,压气机质量流量都趋于降低,压比越低,压气机质量流量下降越明显;加湿后,压气机转速越高,越接近失速点,总温下降越多;湿压缩中水滴蒸发成水蒸气导致压缩的总耗功有较大程度的增加,各工况点都增加了500 kW以上;加湿后最严重的动叶叶尖处叶背分离点是否能够得到改善与具体的工况点有关,且存在一个临界工况点,在本研究的算例中,这个临界点约为90%转速。The wet compression technology can effectively enhance the power output of a gas turbine and lower the degree of dependence of the gas turbine on the atmospheric environment.The factors the technology influences the compressor are very intricate and the operating conditions of the compressor have a very big influence on the wet compression effectiveness.By employing software CFX,a three-dimensional numerical simulation was performed of the dry and wet compression process of a three-stage axial compressor under different operating conditions.The research results show that under the condition of the pressure ratio keeping constant,the mass flow rate will increase at a high speed and decrease at a low speed at the boundary where the compressor approximates to its stall.Under the condition of the rotating speed keeping unchanged,both pressure ratio and mass flow rate of the compressor will tend to decrease.The lower the pressure ratio,more conspicuously the mass flow rate of the compressor will decrease.After the compressor has been humidified,the higher the rotating speed of the compressor,the more it approximates to its stall point and the more the total temperature will decrease.During the wet compression,the water drops are vaporized into steam,resulting in an increase of the total power consumed by the compression to a relatively big extent.All the calculation cases have increased by more than 500 kW at various operating points.After the compressor has been humidified,whether the worst separation point on the back of the rotor blades at their tips can be improved is related to the concrete operating point and there exists certainly a critical operating point.For the cases calculated by the authors,the above-cited critical point is assessed at about 90% of the rated speed.

关 键 词：燃气轮机 压气机 湿压缩性能 变工况 数值模拟 

分 类 号：TK14[动力工程及工程热物理—热能工程]