The effect of water phase content in coal-water fuel on regularities of the fuel ignition and combustion

Abstract Despite all efforts, alternative energy sources cannot meet the growing energy demand of humanity at the moment; and coal keeps its position as an energy source. One the main problem of the coal-water fuel utilizing is to find the balance between its rheological properties, mainly its viscosity, which defines the efficient feeding and atomization of fuel, and combustion efficiency. Fuel viscosity is determined by the fraction of the water phase in fuel. On the other hand, water can influence negatively the combustion process. This paper describes the results of the experimental investigations on the influence of the water phase contents in the coal-water fuel on its combustion efficiency. It was found, that there is an optimal value of the water phase in the coal-water fuel. This optimal value is independent on general combustion parameters like the temperature of the oven medium and source coal metamorphic stage. It characterizes the rational combination of chemical and thermal processes involved in the fuel combustion. The results obtained are new and made a significant contribution to knowledge. They allow changing the viewpoint on the development of the methods for improvement of the utilizing of such type of fuel.