一种适用范围更广的核主泵惰转计算方法

A More Widely Applicable Calculation Method for Coastdown of Reactor Coolant Pump

采用成熟的RELAP数值计算模型研究了基于相似理论的惰转转速和惰转流量理论公式的适用范围,进而首次提出了一种适用范围更广的核主泵惰转计算方法。基于相似理论的惰转转速理论公式基本适用于初始动能比(ε)<3时的工况;惰转流量理论公式适用于ε<0.3时的工况。在ε≥0.3时,惰转过程流量、转矩、扬程和ε特性偏离相似工况,导致惰转转速和惰转流量理论公式的假设前提不成立,故理论公式计算结果产生较大偏差。一般压水堆核电厂反应堆冷却剂回路、主泵试验台架的ε<0.3,惰转转速和惰转流量理论公式均适用,计算误差总体上不超过10%,且惰转转速计算误差小于惰转流量计算误差。本文提出了用于ε≥0.3情况的惰转流量理论公式修正公式,拓展了惰转理论公式的应用范围,可用于新型反应堆的研发。

The applicable range of coastdown speed and flow analytical formulae based on similarity theory was investigated by using mature RELAP numerical calculation model,and then a more widely applicable calculation method for Reactor Coolant Pump(RCP)coastdown calculation was first proposed.The analytical formula of coastdown speed based on similarity theory is basically applicable to the conditions when the initial kinetic energy ratio(ε)is less than 3,while the analytical flow coastdown formula applicability is limited to conditions for whichεis lower than 0.3.Whenε≥0.3,the characteristics of flow,torque,head andεdeviate from similar conditions,which leads to invalid assumption of coastdown formulae,resulting in large error in calculation results of the formulae.Both the speed and flow coastdown formulae are applicable to coastdown calculation of PWR Reactor Coolant System and RCP test loops,because theirεis normally below 0.3;the error of coastdown formulae are within 10%normally,and the calculated speed error is less than flow error.A correction method for coastdown flow formula withε≥0.3 is proposed in this paper,which extends the applicable range of coastdown flow formula and is applicable for new reactor development.low formula withεbeyond 0.3 was developed,which expands the applicable range of coastdown formula and is applicable for new reactor development.