陕西镇安抽水蓄能电站蜗壳保压值合理性分析

Rationality Analysis of the Preloading Water Head of the Spiral Case in Zhen'an Pumped Storage Power Station

蜗壳保压值过低会导致蜗壳外包混凝土受力过大,增加钢筋混凝土结构工程量,而保压值过高则会造成低水压运行过程中蜗壳与外包混凝土形成脱空现象,对蜗壳结构运行稳定性和机组抗振性能不利,因此,蜗壳保压值的合理性是确保抽水蓄能电站安全稳定运行的关键因素。结合镇安抽水蓄能电站工程实际,运用三维有限元分析软件ANSYS,计算分析不同保压值下蜗壳结构应力、承载比、混凝土配筋等情况。结果表明,本工程钢蜗壳采用3.8 MPa的保压值时,不仅可以保证机组稳定运行,同时能够充分发挥钢蜗壳外包混凝土的受力特性,是合理的保压水头。

Low preloading water head of spiral case will lead to excessive stress on surrounding concrete of spiral case and increase the quantities of reinforced concrete structure,while high preloading water head will cause void between spiral case and surrounding concrete when operating under low water pressure,which has an adverse impact on the integrity of spiral case structure and the vibration resistance of the unit.Therefore,a reasonable preloading water head of spiral case is key to ensure the safe and stable operation of pumped storage power station.Combined with the engineering practice of Zhen'an pumped storage power station,this paper analyzes the stress,bearing ratio and concrete reinforcement of the spiral case structure under different preloading water heads by ANSYS.The results show that when the retention pressure value of 3.8Mpa is adopted for the steel spiral case of the power station,it can not only ensure the stable operation of the unit,but also give full play to the stress characteristics of the steel spiral case enclosed with concrete.Therefore,it is a reasonable preloading water head.