THEORETICAL STUDY OF NONSTATIONARY AIR GASIFICATION OF SOLID FUEL IN A FIXED BED AT ATMOSPHERIC PRESSURE


Keywords: fixed bed, coal, thermal conductivity, air gasification, conductive, radiation, temperature.

Abstract

Based on the system of equations describing the process of coal conversion in the steam-oxygen mixture, a non-stationary model of air gasification of solid fuel in a fixed bed was constructed with allowance of interphase convective heat exchange, radiation-conductive heat transfer of the solid phase, radiant and conductive heat exchange of the bed with the reactor wall, heterogeneous chemical reactions, gravity and aerodynamic force. The proposed model provides detailed information on the geometric, aerodynamic, thermal, and physicochemical parameters of air gasification of solid fuel in a fixed bed at different pressures at any time. This data can be used in the draft, technical and detailed reactors designing, commissioning and operation of the gas generator on sliding loads, when the process of air coal gasification is non-stationary. It has been shown that: a) the main gasification process of coke-ash particles occurs in a small area of a fixed bed of 91 mm, which leads to a decrease in the temperature of the solid phase by 160 °C and a concentration of CO2 → 0, as a result of which the remaining part of the gasification interval of ~ 185 mm  is ineffective; b) the section of the oxidation zone, where the temperature of the coke-ash particles reaches its maximum value, is very narrow ~ 34–41 mm; c) in the time interval of 1951–4052 s, where intensive displacement of the boundaries of the oxidation and gasification zones along the bed height occurs, the composition of the synthetic gas (by volume) at the reactor exit remains almost constant: CO = 34,32% and N2 = 65,66 %. Ref. 8, fig. 6.

References

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Author Biographies

B. Rokhman, Coal Energy Technology Institute NAS of Ukraine, 04070, Kyiv, str. Andreevskaya 19

Rokhman.jpgAuthor information: the leading researcher of the Institute of Coal Energy Technologies of the NAS of Ukraine, Doctor of Technical Sciences. Biographical information of Rohman B.B. is published in well-known world directories "Who's Who in Science and Engineering" and "2000 Outstanding Intellectuals of the 21st Century".
Education: Novocherkassk Polytechnic Institute.
Research area: Mathematical modeling of aerodynamics, heat and mass transfer and chemical reaction of a polydisperse ensemble of solid fuel in chamber and layer furnaces, in reactors with a circulating fluidized bed and in the fluidized bed.
Publications: more than 90 scientific papers, 27 of them are contained in the science-based Scopus database and 4 in the science-based  Web of Science database.

M. Nekhamin, Institute of Coal Energy Technology NAS Ukraine, 04070, 19 Andreevskaya st., Kyiv, Ukraine.

Nekhamin.pngAuthor information: senior staff scientist of Institute of Coal Energy Technologies of  NAS of Ukraine, candidate of technical sciences.
Education: Finished the Kharkov aviation institute on May, 28 1965 and post-graduate course of Institute of electrodynamics of  NAS of Ukraine on 01.11.1970. Worked in the institutes of Academy of Sciences of Ukraine in positions of junior scientist, senior engineer, leader of group, senior staff scientist. Protected dissertation of candidate of engineering sciences on April, 21 1982.
Research area: numeral modeling of processes of aerodynamics, heat and mass transfer in power plants.
Publications: more than 70 scientific papers.


Abstract views: 42
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Published
2020-03-30
How to Cite
Rokhman, B., & Nekhamin, M. (2020). THEORETICAL STUDY OF NONSTATIONARY AIR GASIFICATION OF SOLID FUEL IN A FIXED BED AT ATMOSPHERIC PRESSURE. Vidnovluvana Energetika, (1(60), 86-95. https://doi.org/https://doi.org/10.36296/1819-8058.2020.1(60).86-95