Among the available mitigation options for CO₂ emissions, oxy-fuel combustion technology has been gaining significant attention as a promising technology for curtailing the CO₂ emission. Currently the technology is at the demonstration phase on existing coal and gas power plants and some new pilot plants are being tested. In spite of the prospect, to integrate oxy-combustion to fire-tube boilers, heat transfer challenges need to be addressed due to fragility of the membrane at the hostile operating conditions. In the current study, numerical modeling of a two-pass oxygen transport reactor for fire-tube boiler was conducted to investigate the heat transfer characteristics to the saturated water and steam at various operating pressures, emissivities and thermal conductivities. The results indicate that the effect of varying the boiler thermal load resulted in slight decrease in heat transferred by only about 2% at 50 bar, at fixed fuel firing rate. Despite this insignificant increase in the total heat transferred, the combustion component of the total heat transferred decreases significantly by about 16% at 50 bar. The combustion efficiency was also found to decrease by only about 0.03%, which is considered as insignificant. The total heat transferred to the load slightly decreases as the emissivity of pipes increases up to the emissivity of 0.95 beyond which the heat transferred decreased drastically at emissivity of 1 due to the flame quenching. The optimum thermal conductivity of the inner pipe to deliver highest heat to the load by ensuring flame availability, maximum combustion efficiency of 98.58% as well as optimum heat transfer is found to be 0.1 W/m-K. There were no significant variations in heat transferred and combustion efficiency when the emissivity of the membrane was varied between 0.5 and 1.

在对CO可用的缓解方案₂的排放量，全氧燃烧技术已获得显著关注作为一个有前途的技术用于削减二氧化碳₂排放。目前，该技术正处于现有煤和天然气发电厂的示范阶段，一些新的试点工厂正在测试中。尽管前景广阔，但要将氧燃烧集成到火管锅炉中，由于膜在恶劣的操作条件下易碎，传热挑战需要解决。在目前的研究中，对火管锅炉的二回程氧传输反应器进行了数值模拟，以研究在不同操作压力、发射率和热导率下对饱和水和蒸汽的传热特性。结果表明，在固定燃料燃烧率下，改变锅炉热负荷的影响导致在 50 bar 压力下传递的热量仅减少约 2%。尽管传递的总热量没有显着增加，在 50 bar 时，总热量的燃烧成分显着降低了约 16%。还发现燃烧效率仅降低了约 0.03%，这被认为是微不足道的。当管道的发射率增加到 0.95 时，传递到负载的总热量略有下降，超过 0.95 时，由于火焰淬火，在发射率 1 时传递的热量急剧下降。通过确保火焰可用性、98.58% 的最大燃烧效率以及最佳热传递，内管的最佳导热系数为负载提供最高热量，被发现为 0.1 W/mK。当膜的发射率在 0.5 和 1 之间变化时，传热和燃烧效率没有显着变化。