3 ) . the flow velocity and temperature change rapidly in hot plenum under the transient condition such as in the case of reactor scram condition . thermal stratification phenomena will be observed nearby the inlet of intermediate heat exchanger 在事故停堆后的瞬态分析中,热钠池的流场和温场变化剧烈,并在中间热交换器的入口附近形成稳定的热分层。