Analysis of the distribution of temperature in pulverized coal gasifier based on random simulation

Temperature is the core process parameter affecting gasification performance，and it is important to charac⁃ terize and analyze its distribution in the gasifier as accurately as possible to ensure that gasification performance and maintained the safety of gasification process. The temperature is considered as a spatial random variable， and the temperature distribution in two longitudinal profiles (center of the gasifier and near the furnace wall) of the gasifier is simulated stochastically and analyzed for spatial correlation in the furnace by building a two⁃dimen⁃ sional random field model. Numerical simulations were carried out using FLUENT simulation software and comple⁃ ted temperature sampling，then the temperature random field model was built using the matrix decomposition method and discretized using the center point method，and the temperature distribution states of two longitudinal profiles of random field simulation and deterministic simulation as well as the temperatures of syngas outlet and ash outlet were compared and analyzed.The spatial correlation coefficients of temperature units at different locations are calculat⁃ ed to further investigate the spatial correlation of temperature distribution at different locations in the redox region.The results show that under the random field simulation，the temperatures in the upper and lower exit areas of the two longi⁃ tudinal profiles of the gasifier show a random distribution， which is more consistent with the actual operation of coal gasification.Compared with the deterministic simulation，the maximum temperature of the two longitudinal pro⁃ files decreases，but the syngas outlet temperature and the average slag outlet temperature both increase.Further analysis of the spatial correlation of temperature distribution shows that the maximum spatial correlation of temperature distribu⁃ tion in the oxidation zone of different longitudinal profiles is higher than that in the reduction zone，and the aver⁃ age correlation is lower than that in the reduction zone，however，the spatial correlation coefficients of different regions are around 0.5.The ability of the gasifier to rely on its own regulation of temperature distribution to ensure efficient and smooth gasification process is weak，and human intervention is required to change the operating conditions.