极小样本下钠冷快堆主泵上部轴承可靠性评估方法对比分析

Comparative Analysis on the Reliability Estimating Method for Components of the Primary Pump of the Sodium-cooled Fast Reactor with Extreme Small Scale Sample Test

钠冷快堆主泵具有长寿命和高可靠性的要求,但由于研发和试验成本、试验周期以及试验条件等各方面因素的限制而无法进行大量试验。因此,针对目前钠泵上部轴承完成582次启停试验未失效的情况,使用了两种极小样本可靠性评估方法综合概率评估法、虚拟增广样本+Bootstrap方法,对上部轴承磨损寿命进行了可靠性评估。计算结果表明,综合概率分布评估法得到的部件综合概率密度函数更接近于真实的概率密度函数,虚拟增广样本方法的评估结果精度较高。分析结果为钠泵部件在极小样本情况下的可靠性评估提供了理论依据,在节省试验费用、减少试验次数、缩短研发周期等方面具有显著的工程意义,解决了只有一个试验数据时产品可靠性评定的难题。

Long life and high reliability were required for the primary pump of sodium-cooled fast reactor(SFR), and a large number of tests were limited for the cost of R&D and test, test cycles and test conditions and other factors. For the top bearing of the primary pump has completed 582 start-stop tests without failure, synthesis probability distribution estimation method and virtual expanding estimation method were introduced and the wear life reliability for the top bearing of the primary pump was evaluated by using the two methods. The calculation results show that the synthesis probability density function obtained by the synthesis probability distribution estimation method is closer to the true probability density function, and the virtual expanding estimation method has higher precision. The results provide a theoretical basis for the reliability estimation of the primary pump components in the case of very small samples, which has significant engineering significance in saving test expenses, reducing the times of test and shortening the research cycle. The problem of reliability assessment with only one experimental datum was solved.