高温气冷堆螺旋管式直流蒸汽发生器热工水力学

Thermal Hydraulics of HTGR Helical Tube Once Through Steam Generator

高温气冷堆蒸汽发生器具有一次侧氦气工质、二次侧直流、螺旋管结构、工作温度高等特点,其热工水力特性与传统压水堆自然循环蒸汽发生器存在很大区别。针对高温气冷堆蒸汽发生器的特点,对其基础热工水力及特有热工水力学问题进行了阐述,主要包括螺旋管内单相及两相流阻及换热计算、横掠螺旋管束流阻及换热计算、温度均匀性及两相流不稳定性等。同时介绍了清华大学核能与新能源技术研究院针对高温气冷堆蒸汽发生器热工设计、温度均匀性及两相流不稳定性等热工水力学问题所开发的一维稳态程序、一维瞬态程序、二维分析程序和方法,并对分析结果和结论进行了讨论。相关研究方法、程序和结论对其他相似参数螺旋管和直管式直流蒸汽发生器具有参考和借鉴意义。

The steam generators (SG) of high temperature gas-cooled reactor ( HTGR ) have the characteristics of using helium as coolant in the primary side,once through flow pattern in the secondary side,helical tubes for heat transfer and high working temperature,etc.These make the thermal hydraulic characteristics of HTGR SG differ a lot from the conventional natural circulation SG of pressurized water reactor (PWR).The basic thermal hydraulics and specific thermal hydraulic issues of HTGR SG were described,including the single-phase and two-phase pressure drop and heat transfer calculation in helical tubes,pressure drop and heat transfer of cross flow over helical tube bundles,temperature uniformity and two-phase flow instabilities.The one dimensional steady code,one-dimensional transient code,two-dimensional codes and methods developed by Institute of Nuclear and New Energy Technology (INET),Tsinghua University,for the thermal hydraulic design and for analyzing the temperature uniformity and two-phase flow issues were introduced.The results were presented and discussed.The methods,codes and conclusions can be referenced for other helical tubes or straight tube once through steam generators having similar parameters.