乙烯裂解炉内传递和反应过程综合数值模拟Ⅱ.反应管内传递和反应过程的数值模拟

采用乙烯裂解炉传递反应过程综合数学模型中的反应管数学模型，对工业裂解炉反应管进行了系统的数值模拟，得到了反应管内流场、温度场和浓度场的详细信息，揭示了反应管内流动、传热、传质和裂解反应的基本特点。模拟结果表明，沿反应管轴向油气吸热升温，裂解反应加剧，产物产率逐渐发生变化；沿反应管径向存在明显的流体流速和温度的变化，而产物产率的变化不如流体流速和温度的变化明显。通过比较湍流粘度和分子粘度的大小，认为29．975～30mm的径向区域为层流层，层流层的存在使得临近管壁的区域内流体流速和温度变化显著。

NUMERICAL SIMULATION OF TRANSFER AND REACTION PROCESSES IN ETHYLENE PYROLYZER Ⅱ.Numerical Simulation of Transfer and Reaction Processes inside Tubular Reactors

Numerical simulation on the flow,heat transfer,mass transfer and thermal cracking reactions in industrial tubular reactors was carried out by employing the developed tubular reactors model. Some detailed information about the flow field,temperature field and concentration distribution in tubular reactors was obtained,presenting the basic characteristics of the flow,heat transfer,mass transfer and thermal cracking reactions. The profiles of oil gas temperature and main component concentrations along the axial position were studied. Radial profiles of velocity and temperature showed obvious changes,but the radial profiles of product yields did not show so obvious changes.A comparison of turbulent viscosity with molecular viscosity was made in radial position,showing a laminar flow in the radial region from radius of 29.975mm to 30 mm,which resulted in the steep gradients of velocity and temperature near the wall.