摘要
以某废热锅炉蒸发器(壳管式换热器,烟气在管内流动,水在壳侧流动)为研究对象,应用Mixture多相流模型和沸腾传质模型,对壳侧两相流区域的沸腾传热进行数值模拟。根据壳侧气液两相流区域蒸汽平均体积分数随蒸汽出口管内直径的变化,选取合适的内直径,分析壳侧两相流区域的蒸汽体积分数及温度、压力分布。随着模拟时间延长,壳侧两相流区域蒸汽平均体积分数逐渐增大,因此蒸汽出口管内直径应确保蒸汽顺利排出。沿蒸发器轴线至外壁方向,两相流温度逐渐下降。两相流在出口附近的压力下降比较明显,这是由于出口边界设置为常压。
Taking a waste heat boiler evaporator that has a shell-tube type heat exchanger where smoke flows in the inner tube and water flows in the shell side as the research object, the boiling heat transfer in the two-phase flow zone of the shell side is numerically simulated by Mixture muhiphase flow model and boil- ing mass transfer model. According to the change of the average volume fraction of steam in the gas-liquid two-phase flow zone of the shell side with the inner diameter of the steam outlet pipe, the suitable inner diameter is selected to analyze the steam volume fraction, temperature and pressure distribution in the two- phase flow zone of the shell side. Along with prolonging of the simulation time, the average volume fraction of steam in the two-phase flow zone of the shell side increases gradually, so the inner diameter of the steam outlet pipe should ensure that the steam is discharged smoothly. The two-phase flow temperature gradually decreases along the axis of the evaporator to the outer wall. The pressure drop of the two-phase flow near the outlet is more obvious because the outlet boundary is set to normal pressure.
出处
《煤气与热力》
2016年第3期1-4,共4页
Gas & Heat
关键词
废热锅炉
沸腾传热
两相流
数值模拟
waste heat boiler
boiling heat transfer
two-phase flow
numerical simulation
