DESIGN FEATURES OF THE EXPERIMENTAL UNIT AND NUMERICAL STUDIES OF BIOMASS THERMO-CHEMICAL PROCESSING PART 4 CALCULATIONS RESULTS OF ELECTRIC HEATERS AND COKE ASH RESIDUE GASIFICATION

• Datum: 2025
• Hauptverfasser: Rokhman, B., Kobzar, S., Chetveryk , H., Senchyk , M.
• Format: Artikel
• Sprache: Ukrainian
• Veröffentlicht: Institute of Renewable Energy National Academy of Sciences of Ukraine 2025
• Schlagworte: fixed bed; biomass; Wood Birch; thermal conductivity; pyrolysis; gas; temperature; thermal energy; recycling; electric heater.
• Online Zugang: https://ve.org.ua/index.php/journal/article/view/517
• Назва журналу: Vidnovluvana energetika

The fourth part of this work is devoted to the development of designs of electric heaters for the pyrolyzer external and in-ternal heating surfaces, providing stable operation at the maximum load of 320000-330000 W/m2 at the temperature of enclosing surfaces 950 С. The results of calculations show that for stable operation in the specified range of loads the electric heater structures should consist of two parallel spirals made of nichrome and tungsten wires. The main characteris-tics of nichrome spirals: for the inner surface (tube diameter 190 mm) − wire diameter − 3,5 mm, current strength − 116,5 A, wire length − 27,74 m; for the outer surface (diameter 260 mm) − wire diameter − 4 mm, current strength − 154,5 A, wire length − 27,4 m. Spirals made of tungsten: for the inner surface − diameter − 0,6 mm, current strength − 116,5 A, length − 22 m; for the outer surface − diameter − 1,2 mm, current strength − 154,5 A, length − 39,3 m. The use of pyrolysis gas recirculation as a third heat source reduced the heating time of the Wood Birch particle bed from 48 to 34,5 s, which resulted in an increase in the bed heating rate from 975 to 1355 С/min. Using the model described in the first part of the work, numerical studies of the process of gasification of coke-sol residues of Birch and Bagasse particles were carried out. At the outlet of the gas generator untreated low-calorie syn-thetic gases of the following compositions were obtained: from Wood Birch CO2 = 4,48 %, CO = 30,41 %, H2 = 16,9 %, H2О = 4,93 % and N2 = 43,3 % with calorific value of 5668 kJ/nm3; from Bagasse − CO2 = 3,370 %, CO = 32,9 %, H2 = 17,64 %, H2О = 3,73 % and N2 = 42,36 % with calorific value of 6062 kJ/nm3. These gases are tar-free and can be used in combustion chambers of reciprocating engines installed at mini-CHPs.