水泵水轮机转轮湿模态和考虑稳态与瞬态水力激励的全寿命模型研究

Pumped Storage Power Station undertaking the role of peak regulation, frequency modulation, phase modulation, and emergency reserve, has an irreplaceable function in the power system. According to the power industry "12th Five-Year Plan", it is also a tremendous potential market in pumped storage unit equipments. The pump-turbine as the key component of pumped storage has a complex structure,a bad environment, higher risk equipment operating, higher technical threshold, and theory and technology research should be strengthened. The high frequency of the transition process and multiple loading conditions lead to a more intense vibration, seriously affecting the pump-turbine life.This research will be carried out to analysis the pump-turbine runner's wet modes and total fatigue life model considering the steady-state and transient hydraulic exictation.Study on the added mass and modal in an aqueous medium, and understand the vibration characteristics in order to avoid resonance in the operation area. After that, dynamic stresses based on the fluid-structure interaction(FSI) will be calculated in typical steady state conditions and the transition process of the pump-turbine; the load spectrum to reflect the actual operating conditions also be compiled. Then the total fatigue life model is carried out to estimate the pump-turbine fatigue life under the hydraulic excitation in multiple complex conditions. Finally, the results of these studies is expected to promote the research on the basic theory of Pumped Storage Power Station as well as the large hydraulic machinery.

抽水蓄能电站承担着调峰、调频、调相和事故备用等作用，在电力系统中有着不可替代的功能。根据电力工业"十二五"规划，未来二十年内抽水蓄能机组设备市场空间巨大。抽水蓄能机组核心部件水泵水轮机结构复杂，工作环境恶劣，设备运行风险较大，技术门槛较高，相关理论和技术研究亟待加强。水泵水轮机频繁的工况转换导致水泵水轮机振动较为剧烈，机组寿命受到严重影响。本申请将开展水泵水轮机转轮湿模态和考虑稳态与瞬态水力激励力特性的全寿命模型研究，探讨转轮在水介质中的附加质量和模态特性；然后对水泵水轮机的典型过渡过程进行基于流体动力学的流固耦合动应力分析，结合稳态多工况与过渡过程运行特点编制反映实际运行条件的载荷谱，运用全寿命模型计算水泵水轮机转轮在稳态与瞬态激励下的疲劳寿命特性。研究成果有望促进抽水蓄能机组乃至大型水力机械转轮模态分析与全寿命预测的基础理论研究。

水泵水轮机组开停机频繁，工况转换过程复杂，常引起极大地水力激励作用，这些都会严重影响转轮的动力特性和疲劳寿命特性。对水力机械危险部位容限损伤和耐久性分析方面的研究尚在起步阶段。考虑到水轮机在制造、使用和维护过程中，转轮结构不可避免的存在各种缺陷，利用断裂力学理论，评价水轮机转轮结构在使用中的抗疲劳断裂强度特性，对提高其维修经济性和延长使用寿命具有重要意义。本课题的研究对象为500米水头、水轮机工况额定出力为306 MW的水泵水轮机。以CFD水力激励力计算结果为载荷边界条件，开展水泵水轮机转轮湿模态和考虑稳态与瞬态水力激励力特性的全寿命模型研究，探讨转轮在水介质中的附加质量和模态特性；然后对水泵水轮机的典型过渡过程进行基于流体动力学的流固耦合动应力分析，结合稳态多工况与过渡过程运行特点编制反映实际运行条件的载荷谱，运用全寿命模型计算水泵水轮机转轮在稳态与瞬态激励下的疲劳寿命特性。研究成果有望促进抽水蓄能机组乃至大型水力机械转轮模态分析与全寿命预测的基础理论研究。