【摘要】 火电机组参与电网深度灵活调峰已成为当代电力发展的新常态,在机组低负荷深调过程中,蒸汽流量较小。本文针对调峰机组汽轮机末级叶片小容积流量问题进行了模态特性及动应力响应进行数值模拟研究,结果表明:末级叶片在2 820～3 090 rpm之间无共振点,而额定温度范围内整圈叶片无共振转速;以模态分析为基础综合考虑变温特性下得出叶片伸长量,可为现场叶片汽封调整作为参考。基于额定工况与2.2 kPa、40 t/h工况下的动应力满足设计要求,而其他非设计工况下的动应力已超出了叶片的耐振强度,全工况动静应力极值均处于叶型根部出汽侧,导致叶片的耐振强度许用值较低。上述数值结果为电厂调试提供了理论支撑,同时也为机组经济性运行作出了技术指导。更多还原

【Abstract】 It has become a normal state of modern power development that the participation of thermal power units in the depth and flexible peak shaving of the power grid. In this process, the steam flow of unit is small. In this paper, the modal characteristics and dynamic stress response of turbine last blade with small volume flow are numerically simulated.The results show that the last blade has no resonance point between 2 820～3 090 rpm, and the whole temperature range maintained in a rated temperature range, in which blade has no resonance speed. Based on the modal analysis, the blade elongation is obtained by comprehensively considering the temperature change characteristics, which can be used as a reference for the adjustment of blade seal. In view of the dynamic stress of rated working condition and 2.2 kPa,40 t/h working condition, the design requirement were reached, while the dynamic stress of other non-design working condition had exceeded the blade’s anti-vibration strength, meanwhile the extreme values of dynamic and static stresses were at the outlet side of the blade root, which resulted in a lower allowable value of blade vibration resistance. The above numerical results could not merely provide.更多还原