钠冷快堆直流蒸汽发生器建模与仿真研究

Study on Modeling and Simulation of Once-Through Steam Generator in Sodium-cooled Fast Reactors

为了研究液态金属冷却快堆的运行模式和控制方案,需要对直流蒸汽发生器进行合理的建模仿真,以研究其动态特性。针对某大型钠冷快堆的直流式蒸汽发生器,采用Matlab/Simulink平台,基于三大守恒方程,建立了一种工艺仿真模型,包括稳态计算方法和瞬态计算模型。仿真结果表明,该模型的稳态精度较高,与设计参数的稳态误差在1%以内,且计算速度较快,能够满足控制系统设计的需求。基于该模型,对蒸汽发生器出口蒸汽参数的动态响应特性进行了仿真研究,得到了出口蒸汽和温度随入口钠、水参数阶跃变化的特性曲线,发现在其他条件不变时,直流蒸汽发生器出口蒸汽温度主要受入口钠温度影响,而出口蒸汽压力的主要影响因素为给水流量。在设计控制系统时,应当将钠入口温度作为蒸汽温度的主要调节参数,而将给水流量作为蒸汽压力的主要调节参数。

In order to study the operation mode and control scheme of liquid metal cooled fast reactor,a reasonable modeling simulation of Once-Through steam generator is needed to study its dynamic characteristics.As for the Once-Through steam generator of a fast reactor,a simulation model,including a steady-state calculation method and a transient calculation model,is established based on three major conservation equations using Matlas/Simulink platform.The simulation results show that the steady-state accuracy of the model is high,the steady-state error with the design parameters is within 1%,and the calculation speed is fast,which can meet the requirements of the control system design.Based on this model,the dynamic response characteristics of the steam generator outlet steam parameters were simulated and studied,and the characteristic curves of the outlet steam and temperature with the step change of the inlet sodium and water parameters were obtained.It was found that the outlet steam temperature of the Once-Through steam generator(OTSG)is mainly influenced by the sodium inlet temperature,while the main influencing factor of the outlet steam pressure is the feedwater flow rate,when other conditions are constant.When designing the control system,the sodium inlet temperature should be used as the main regulation parameter for steam temperature,while the feedwater flow rate should be used as the main regulation parameter for steam pressure.