Moumane M. Increasing the efficiency of coal-water fuel combustion by adding waste from biodiesel production

The thesis has solved an urgent scientific and technical issue, which is to increase the energy efficiency of the burning coal-water fuel process by adding biodiesel production waste. The experimentally determined thermophysical properties of fuel have been taken into account alongside with regularities found and determination of appropriate conditions for ignition and combustion of fuel with maximum energy potential and minimizing the negative impact on the environment. For the first time under the conditions of adding glycerol to coal-water fuel as a waste of biofuel production in the amount of 5… 20% of the mass the influence of the glycerol on the fuel heat capacity and thermal conductivity was experimentally determined, which allowed to establish the corresponding empirical dependencies. The data about the regularity of the effect of glycerol content in the range of 5 ... 20% mass in the coal-water fuel on the duration and temperature of each stage of combustion were further developed. This which allowed to determine the rational conditions for increasing the efficiency of fuel combustion. The ideas about the regularities of heat transfer during forced motion of coal-water fuel as a non-Newtonian fluid have been further developed taking into account the obtained thermophysical properties. Also, the criterial similarity equations of the form Nu = f(Gz) for the range of Péclet number of 137…15∙105 have been established for the first time. Practical recommendations for designing heat-transfer apparatuses for thermal activation of coal-water fuel at 150-200°С have been obtained. The data on the regularities of formation of nitrogen- and sulfur-containing compounds in the combustion products of coal-water fuel depending on the content of glycerol in it and the process temperature were further developed. This allowed to determine the combustion conditions that reduce the negative impact on the environment. The rational parameters of efficient combustion of coal-water fuel with the addition of glycerol are proposed. They provide the maximum realization of the fuel energy potential with a reduction of the negative impact on the environment. The operating parameters of furnaces while using coal-water fuel with the addition of glycerol for their heating have been developed for implementation at the lime production site of Dnipro Steel Ltd.