Optimization of oil shale retorting process based on heat transfer model

To optimize the oil shale retorting process and improve the thermal efficiency of the retort, a heat transfer model of the oil shale retorting in the Fushun-type retort was established based on the gas-solid heat transfer equation. The orthogonal experimental method was used, with hot air volume (A), hot recycle gas temperature (B), and oil shale interparticle porosity (C) taken as the investigation factors, and the retort height required for the retorting of the same quality oil shale as the metric of the thermal efficiency of the retort. The smaller the retort height, the higher the thermal efficiency of the retort. Range and variance analyses revealed that the effects of the three factors on retort height are, from large to small: A > B >C; this shows that hot air volume (A) exerts the most significant influence. Based on this, computational fluid dynamics simulation was conducted on the hot air volume parameter. The study shows that increasing the hot air volume can effectively increase the heat supply proportion of the generated gas in the retorting process to 59.288%. To maintain the height of the high-temperature zone in the reaction section, it is proposed to increase the oxygen content in the hot air volume, which proves the feasibility of oxygen-enriched retorting.