利用数值模拟方法对梅花管、MERT管和扭曲片管3种强化传热炉管进行了流动和传热特性的研究.采用RNGk -ε湍流模型求解了动量方程和能量方程,给出了3种强化传热炉管的流动和传热特性,包括速度场、湍动强度场和温度场的分布；计算了3种强化传热炉管的压降、摩擦系数、努塞尔数(Nu)和强化传热综合因子.研究结果表明,梅花管主体为活塞流,MERT管和扭曲片管为旋转流；管内湍动强度在强化传热构件附近相对较大；管内流体温度场比较均匀.由强化传热元件产生的压降和摩擦系数的大小顺序为:MERT管＞梅花管＞扭曲片管；Nu的大小顺序为:MERT管＞梅花管＞扭曲片管；强化传热效果的优劣顺序为:扭曲片管＞梅花管＞MERT管.%The flow and heat transfer characters of plum blossom-shape tube( PBT), mixing element radiant tube ( MERT) and swirling element of radiant tube ( SERT), which were used in cracking furnaces for ethylene production, were studied by numerical simulation. The momentum and energy equations were solved using RNG k-s turbulent flow model. The flow and heat transfer characters of the three strengthened heat transfer tubes, namely the velocity field, the turbulent flow field, the temperature field, the pressure drop, the frictional coefficient, the Nusselt number (Nu) and the comprehensive factor for strengthened heat transfer, were presented or calculated. The results showed that the main flow pattern in PBT was plug flow while the flow patterns in MERT and SERT were swirl flows, and the turbulence intensity near the strengthened heat transfer components was obvious big. It was showed that the orders of both the pressure drops and the friction coefficients were MERT > PBT > SERT. It was also indicated that the temperatures in the three heat transfer tube were uniform and the Nu order were MERT > PBT > SERT. Finally, the result showed that the effect of improving heat transfer was in order of SERT, PBT and MERT.
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