套管式直流蒸汽发生器稳态特性分析

Analysis of steady-state characteristics of casing once-through steam generator

新型核动力装置采用结构紧凑的双面加热型套管式直流蒸汽发生器,单相一次侧流体在中心管及环形通道外的空间内由上而下流动;二次侧流体在环形狭窄流道内由下而上流动,经过相变在出口处变为过热蒸汽.由于套管式直流蒸汽发生器工作原理与自然循环蒸汽发生器有着本质的不同,为保证其安全可靠的运行,需要研究其稳态和动态运行特性,解决启停过程和升降负荷过程所可能遇到的问题以及水动力不稳定性、脉动问题,基于此,采用最佳估算程序RE-LAP5/SCDAP/MOD3.4分析了单台套管式直流蒸汽发生器有效传热区的稳态运行特性和规律,从而为启停特性分析、动态特性分析以及控制方案的制定提供稳态参考.

The compact casing once-through steam generator （CC-OTSG） with double-faced heat transfer has been adopted as the next innovation in nuclear power plants. Primary coolant flows from top to bottom in the central pipes and the outside annular spaces. Secondary coolant flows in the middle annular channels, becoming super-heated steam at the outlet. As the operational principles of CC-OTSG are significantly different compared with those of general natural circulation steam generators, it is necessary to study their steady-state and dynamic characteristics. This is needed to resolve flow instability and other problems during normal operational processes. By means of RELAPS/SCDAP/MOD3.4 code, steady-state operational characteristics and principles were analyzed. The results can be used to guide the design of systems for startup and shutdown, analysis of dynamic operational characteristics and choice of operational modes.