CAJ | 학술논문

清华大学核能与新能源技术研究院在建的250 MWt高温气冷堆核电站示范工程(HTR-PM)中蒸汽发生器二回路为亚临界水，由于反应堆能提供750℃的高温氦气，二回路水可提高到超临界压力和温度，采用多堆带一机方案可与超临界蒸汽透平机组匹配，因此研究超临界水在管内的流动、传热以及流动不稳定现象非常重要。本文通过使用RNG k-ε模型耦合强化壁面函数，发现模拟结果与Yamagata等的实验数据符合较好。基于此模型，分析了超临界流体流动时换热系数的变化规律，并采用瞬态计算方法，线性增大加热功率，分析了流动不稳定现象，发现流体一旦进入不稳定区，进出口流量的波动非常严重，甚至出现倒流，应尽可能避免此类现象。
청화대학핵능여신능원기술연구원재건적250 MWt고온기랭퇴핵전참시범공정(HTR-PM)중증기발생기이회로위아림계수，유우반응퇴능제공750℃적고온양기，이회로수가제고도초림계압력화온도，채용다퇴대일궤방안가여초림계증기투평궤조필배，인차연구초림계수재관내적류동、전열이급류동불은정현상비상중요。본문통과사용RNG k-ε모형우합강화벽면함수，발현모의결과여Yamagata등적실험수거부합교호。기우차모형，분석료초림계류체류동시환열계수적변화규률，병채용순태계산방법，선성증대가열공솔，분석료류동불은정현상，발현류체일단진입불은정구，진출구류량적파동비상엄중，심지출현도류，응진가능피면차류현상。
Water in the steam generator secondary circuit in the 250 MWt pebble-bed module high temperature gas-cooled reactor (HTR-PM)which was built by the Institute of Nuclear and New Energy Technology (INET)of Tsinghua University,is subcritical. Its pressure and temperature can increase to supercritical as the reactor provides high temperature helium up to 750 ℃,then the reactors and the supercritical steam genera-tors can work with the supercritical steam turbine by adapting multiple-reactors with one-turbine unit design concept. Therefore, the flow, heat transfer and the flow instability of supercritical water in tubes are of great importance.RNG k-εturbulence model coupled with enhanced wall treatment was applied in the simulation,and the numerical calculation results agree well with the experimental results of Yamagata, et al.The heat transfer coefficients of supercritical water in a tube under various heat fluxes were analyzed based on this model.The flow instability was also studied by line-arly increasing the heating power with time.The results show that the inlet and outlet flow rates oscillate intensely once the flow enters the unstable zone and even reserve flow can be observed.Such phenomena should be avoided.