核电机组一二回路耦合变工况分析

Coupled Analysis for Variable Operation Conditions of Primary and Secondary Loops of Nuclear Power Plant Unit

核电机组运行中一回路热功率不允许超出限值,二回路功率的变化一定程度上受到一回路热功率的制约。本文以AP1000核电机组为例,结合一回路的运行特性和二回路热力系统计算方法,提出了核电机组一二回路耦合分析方法,计算结果与设计值的误差小于0.4%,表明本文计算方法具有较好的准确性。分析了负荷调节和季节变化对一二回路运行的影响,结果表明,由于核电机组采用了堆跟机的运行模式,一回路热功率随着汽轮机组输出功率的变化而变化。此外,可通过提升一回路热功率维持汽轮机组输出功率,但是由于一回路热功率不能无限提升,而是受到限值的约束,因此当一回路热功率达到限值后,汽轮机组输出功率将随着循环水温度的升高而降低。

The thermal power of nuclear power plant primary loop is not allowed to exceed the limit, and turbine power depends on the thermal power at a certain extent. In this paper, the operating characteristic of primary loop and thermal system calculation method of secondary loop are combined, and a coupled method is provided to analyze the characteristics of primary and secondary loops of APIO00 nuclear power plant. A good agreement is obtained between the calculations and design parameters with a discrepancy less than O. 4%. The effects of load regulation and season on the operating characteristics are analyzed. The results indicate that the thermal power of primary loop varies with the turbine power due to the operat- ing mode of reactor following turbine. Moreover, the turbine power could be maintained by lifting the thermal power of primary loop. But the thermal power is limited under an allowed value, so the turbine power would decreases with the circulation water temperature when the thermal power reaches the limit.