摘 要：凝结水旁路参与调频是一种增强机组调频能力的有效方法，但调频过程中除氧器暂态特性可能会受到一定的影响，从而影响前置泵的运行安全。本文介绍了凝结水旁路参与调频的原理和方案，提出了此过程中除氧器前置泵暂态安全性计算的必要性。基于三点假设，构建了除氧器中凝结水焓值和工作压力、前置泵入口给水焓值和入口汽化压力、前置泵入口温度和有效汽蚀余量的计算模型。结果表明：40%凝结水旁路开度下前置泵有效汽蚀余量最大会下降13.75 m，对安全性造成威胁。该研究为凝结水旁路参与调频的可行性提供理论基础。

Abstract:The frequency modulation with the condensate water bypass is an effective method to enhance the frequency modulation capability of the unit.But the transient characteristics of the deaerator may be affected in the process of frequency modulation.This paper introduces the principle and scheme of the frequency modulation with condensate water bypass and puts forward the necessity of the calculation of the transient safety of the deaerator.Based on three hypotheses,a model is established for calculating the enthalpy of condensation water and working pressure,the enthalpy of feed water of inlet,the inlet vaporization pressure,the inlet temperature of the inlet pump and the effective cavitation allowance.The results show that the NPSH of the front pump will decrease to 13.75 m when the 40% bypass is opened,which is a threat to the safety.This provides a theoretical basis for the feasibility of using the condensate bypass in frequency modulation.

TK223.5