自预热辐射管是一种重要的间接加热设备。针对目前该设备普遍存在的换热效率低及辐射管表面温度均匀性差等问题，本项目提出富氧燃烧式自预热定向辐射管。其技术创新之处在于烟气再循环的结构形式及辐射管的定向辐射表面结构。项目围绕氧气浓度-火焰-辐射管温度分布之间的关系开展深入的机理研究。通过研究氧气浓度对最高燃烧温度及火焰稳定性的影响规律，寻找合理的氧气浓度范围。通过分析定向辐射表面结构形式对边界热流分布的作用机制，探寻有效的定向表面结构。通过实验和数值模拟相结合的方式揭示定向辐射表面结构和位置，以及氧气浓度对辐射管表面温度均匀性的影响规律。在机理研究过程中，申请者拟自主开发多场耦合的热过程数学模型，着重考虑气体非灰辐射特性，及湍流燃烧与辐射传热的耦合作用(TRI)。本研究结果可为自预热辐射管的设计及操控提供理论指导，也可弥补商业软件在传热机理方面的不足。

Self-recuperative radiant tube is an important indirect heating device. In consideration of the problem of the low heat recovery efficiency and the poor radiant tube surface temperature uniformity, the self-recuperative directional radiant tube structure by oxy-fuel combustion way is proposed in the project. Its technological innovation lies in the structural form of flue gas recirculation and the directional radiation surface structure of the radiant tube. Mechanism research on the oxygen concentration-flame- radiant tube temperature distribution will be carried out in the project. By exploring the effect of oxygen concentration on the maximum combustion temperature and flame stability, a reasonable range of oxygen concentration will be obtained. By exploring the effect of the directional radiation surface structure on the boundary heat flux distribution, an effective directional surface structure will be obtained. The relationship to oxygen concentration, directional radiation surface position, and the uniformity of radiant tube surface temperature will be investigated by means of experiment and model. In the process of mechanism research, a multi-field coupling thermal process mathematical model will be developed independently by the applicant. The model would take into account the non-gray radiation characteristics of gas, and the coupling effect of turbulent combustion and radiation heat transfer (TRI). The results of this study can provide theoretical guidance for the design and operation of self-recuperative directional radiant, and can also make up for the shortage of commercial software in heat transfer mechanism.