Pivnenko Y. Increasing the efficiency of combustion of wood waste in furnaces of a fluidized bed of heating boilers

A dissertation for the degree of candidate of technical sciences in specialty 05.23.03 «Ventilation, lighting and heat and gas supply» (19 – Architecture and Construction). - Kharkiv National University of Civil Engineering and Architecture, 2018. One of the main directions of development of the Ukrainian energy industry is the reduction of consumption of natural gas by introducing fuel of biological origin, including wood, into the energy balance of the country. Dissertational work is devoted to the actual questions of ways of increasing the energy and ecological efficiency of combustion in a fluidized bed of wood waste. Experimental installations for studying the fluid dynamics of the fluidized bed, heat transfer and combustion of wood waste in the state of fluidization have been developed. The mathematical planning of experiments was carried out. Experimental studies of hydrodynamics of a fluidized bed of wood waste have been carried out. The influence of wood waste content in the layer of inert material is shown. The limits of the existence of a fluidized bed for different kinds of wood waste, also for granular wood fuel, have been determined. The regression equation for air velocity is obtained, depending on the percentage of wood waste in the layer and the ratio of the criteria of the wood fiber Archimedes and the inert material. The mechanism of heat exchange between a fluidized bed of wood waste and a submerged surface is experimentally investigated. The mode parameters are defined that provide the maximum coefficient of heat transfer. The regression equations for the coefficient of heat transfer between the fluidized bed and the submerged surface are obtained, depending on the particle size and air velocity. The dependence is obtained for the number of fluidization, at which the maximum value of the heat transfer coefficient is reached, depending on the number of Archimedes. The energy and ecological parameters of combustion of wood fuel in a fluidized bed were studied, emissions and combustible substances were determined at combustion of various types of wood waste. The values of heat loss with mechanical q4 and chemical deficiency q3 are determined. The influence of the regime parameters on the emission of harmful substances into the atmosphere is established. Recommendations concerning optimal modes of combustion of wood fuel in a fluidized bed are presented, which provide the most efficient use of fuel during its burning in the fluidized bed and the ecological safety of the process.