作　　者： ; ; ; ; ; ; ;

机构地区： 西安交通大学能源与动力工程学院动力工程多相流国家重点实验室

出　　处： 《西安交通大学学报》 2009年第7期36-39,48,共5页

摘　　要： 针对600 MW超临界"W"火焰锅炉低质量流速水冷壁所采用的内螺纹管及锅炉设计参数,在高压汽水两相流试验台上进行了垂直并联内螺纹管中两相流不稳定性的试验研究,并观测到了压力降和密度波两种形式的脉动.在试验参数范围内就系统压力、质量流速、进口过冷度、上游可压缩容积、出口节流度和不对称加热对两相流不稳定性的影响进行了研究和分析.试验表明,在垂直并联内螺纹管中,压力降型脉动出现在干度较低的水动力曲线负斜率段,为两管整体脉动,而密度波型脉动出现在干度较高的正斜率区域,呈管间脉动.同时,根据试验结果,采用均相流模型得到了不稳定发生的界限关系式,为超临界锅炉低质量流速垂直并联内螺纹管水冷壁的设计与安全运行提供了依据. The experiments on two-phase flow instabilities in parallel vertical internally ribbed tubes were conducted to investigate the hydrodynamic flow characteristics under low mass flux conditions in a 600 MW super-critical W-shaped flame boiler. Two kinds of oscillations, pressure drop oscillation （PDO） and density wave oscillation （DWO）, were observed..The influences of pressure, mass flux, inlet sub-cooling, compressible volume, exit throttling, and asymmetric heat flux on the two-phase instability were explored and analyzed. The results show that the PDO occurred at lower exit quality and in the negative slope portion of the △p-G curves with the inphase oscillating of both channel flow rates,and DWO occurred at higher exit quality and in the positive slope portion of the △p-G curves with the out-phase oscillating of channel flow rates. Based on the testing results and the homogeneous model, the threshold expressions of instability were obtained. It is suggested that these findings may be used in the water wall design and its safe operation in super-critical boilers.

关 键 词： 低质量流速 垂直并联内螺纹管 不稳定性 超临界锅炉 汽水两相流

领　　域： [动力工程及工程热物理] [动力工程及工程热物理]