Basic types of boilers, design variants. Fuel preparation before combustion - grinding and drying of solid fuels, energy balance. Influence of steam parameters and fuel properties on boiler design - influence of calorific value, influence of water, ash, volatile chlorine and nitrogen content. Methodology of new boiler design. Power plant boilers - sub and supercritical, fluidized bed boilers. Recent trends in boiler design - options for boiler efficiency improvement. Materials for boiler construction. Boiler slave equipment - transport lines, fans, precipitators.