Purpose. To build a model of solid fuel gasification in a fixed bed taking into account the velocity of particles, which allows obtaining detailed information about the technological process. To develop an optimal technological scheme of co-firing of pulverized coal particles and peat gas in the TPP-210A boiler. To investigate the process of a binary mix burning. Methodology. The objects of research were pulverized coal of Ukrainian deposits and peat from Volyn region deposits. The developed model was used to calculate the peat gasification process. To study the process of burning a binary blend, ANSYS FLUENT package was used. Findings. A model of solid fuel gasification in a fixed bed has been developed, which differs from the existing models by taking into account the particle velocity and its change. With the aid of this model the detailed information on temperature and concentration fields of the two-phase environment is received. The process of burning binary mix in a TPP-210A boiler is investigated. Originality. It was found that in the time interval 2200 < < 3200 s a stable stationary process of thermochemical processing of peat with q4.1 = 0.130.3% is formed. The profile of the dispersed phase velocity distribution resembles a mirror reflection of the profile of the particle diameter dependence. Practical value. Using the constructed model, the process of thermochemical processing of 28939 kg/h of raw peat in three reactors with a fixed bed at a pressure of 1.5 MPa was numerically investigated. The composition of the generator gas at the reactor outlet was determined.

No abstract

Purpose. To investigate the gasification process of peat in gas generators with a fixed bed at a pressure of 1.5 MPa and create the initial conditions at the entrance to the waste burners required for combustion of the binary mixture. Methodology. The objects of research were peat granules of Volyn peat. To calculate the process of gasification of peat gas, the constructed model of thermochemical processing of solid fuel, described in the first part of the work by the authors was used. Findings. It is shown that in the area close to the upper boundary of the fixed bed, where the process of gasification of peat is stationary, there is a jump in the temperature of peat particles from 300 to 772C, in which the tar is practically not released, and thus the obtained pyrolysis gas contains CO2, H2O, H2 and CO. The structural and physicochemical characteristics of gas generators are obtained and the initial conditions at the entrance to the discharge burners of the chamber furnace of the steam generator TPP-210A are formed. Originality. It is shown that when the velocity of peat particles decreases, a slag bed is formed between the zone of maximum heat release and the grate, which consists of cooled ash particles, which protect the grate from overheating. With such an organization of the process it is possible to achieve the stationary process of gasification with mechanical incompletely burned material equal to zero. Practical value. It is shown that with the help of the model of thermochemical processing of solid fuels it is possible to adjust the height of the dry distillation zone by changing the velocity of the dispersed phase and the rate of heterogeneous and homogeneous chemical reactions by changing the proportion of O2 or H2O air enrichment.