油页岩干馏炉启动升温过程中,其炉内的温度分布特性对油页岩的预热具有显著影响。干馏炉内气体在固体物料间的空隙内流动十分复杂,难以实现模拟研究。试验结果表明,空炉与填料时水平截面的温度分布变化基本相似,可通过空炉时的温度分布特性来进行近似分析。在进气量12m3/s、进气比1的工况下,采用LES和RNS模型分别对空炉下干馏段和布气装置的升温过程进行数值模拟,分析干馏段和布气装置内温度及流速的变化。结果表明,布气方式决定炉内不同区域油页岩发生热解的顺序,率先发生热解的油页岩吸热减少,该位置温度加速上升,加剧炉内温度分布不均;加权平均数公式能更加准确反映截面温度不均性;炉内温度分布主要由不同区域的喷嘴加热功率与该区域的流场特性共同作用形成。
Distributions of temperature affects oil shale pre-heating obviously during starting up and heating process inside retorting reactor. It is hard to conduct numerical simulation for the gas flow behavior, owing to the complexity of gas running through the intervals among the solid material. The experimental results have showed that the trend of interface temperature distribution variation in an empty furnace was similar to that in a packed one. And a numerical simulation of an empty furnace can be carried out to describe approximatively the temperature distribution in the full filled reactor. LES and RNS models were adopted to simulate the heating process in the furnace, under the gas input of 12 m3/s and the quantity ratio of centre and wall gas inlet of 1. The simulation results showed that the pyrolysis sequence of oil shale at different regions depended on the gas distribution. The temperature rising was accelerated at a place where thermal decomposition took place earlier, resulting in intensifing non-uniform distribution of temperature. The weighted mean formula was better than the traditional formula for studying the temperature distribution of sections. The combined action of both the heating power of hot gas from different nozzles and the flow distribution at the same area affected the temperature distribution in retorting reactor. ? 2016, Science Press. All right reserved.