余热锅炉管口区传热的数值分析

Numerical Analysis of Heat Transfer at the Tube Inlet Zone of a Heat Recovery Boiler

应用高温换热设备管口传热分析系统针对某天然气化工厂二次转化气余热锅炉管口区传热问题建立了物理、数学模型 ,进行了相应的数值分析。数值计算结果表明 ,新型双瓷管保护结构改善了管口区的传热性能 ,降低了余热锅炉管口区金属材料的温度 ,减缓了高温腐蚀反应速度 ;新型双瓷管保护结构同时改善了管口区域内保护套管的温度“畸变” ,因而减轻管口区材料的热应力破坏。

On the basis of a heat transfer analysis system for a high temperature heat exchange equipment inlet tube a physical and mathematical model was set up for investigating the heat transfer at the inlet zone of a heat recovery boiler installed at a Natural Gas Chemical Works. Pertinent numerical analyses are conducted. The results of the analyses indicate that the use of an innovative dual porcelain tube based protective structure can improve the heat transfer performance and also reduce the temperature of tube material at the tube inlet zone of the heat recovery boiler. This is conducive to alleviating the high temperature corrosion reaction speed. Meanwhile, the protective structure of this dual porcelain tube can also lessen the 'aberration' of temperature distribution at the tube inlet zone, resulting in a decrease in thermal stress related failures of the tube material at the above mentioned zone.