Presentation on theme: "Impact of Fuel Quality on Design of Steam Generator P M V Subbarao Professor Mechanical Engineering Department The Influence of Natural Resources on Development…."— Presentation transcript:
Impact of Fuel Quality on Design of Steam Generator P M V Subbarao Professor Mechanical Engineering Department The Influence of Natural Resources on Development….
Basic The Theme Steam Generator Design Constrains: Imposed by Cycle Design (p max, T max, etc.) Fuel Combustion Related. Heat Transfer Related Safety and Reliability Related.
Details of Basic Processes Flow of Air and Prepared Fuel –Fluid Dynamics. Generation of Thermal Energy – Using Natural Resources. –Combustion Sciences. Transfer of Thermal Energy to working fluid. –Science of Heat Transfer.
Duties of A Furnace Dixon’s Theory: Generate an environment of excited fuel and oxygen molecules. All the fuel molecules should be surrounded by oxygen molecules. Facilitate frequent collisions among excited fuel molecules and excited fuel molecules. A successful collision can lead to combustion. Realization of Dixon’s Theory using Coal is highly challenging. Many possible technologies are available to realize above conditions with varying levels of success and expenditure. These are called Three Ts and one S technologies.
Five Requisites for Good Combustion Fuel MATt Theory: –M : Proper mixing of the reactants. –A: Sufficient air. –T: Conducive temperature –t: Sufficient time – Satisfactory density of reactant. Fourth DF systems contains various auxiliaries to satisfy MATt theory as completely as possible.
Realization of MATt Theory Mixing: Fuel preparation systems. Air: Draught systems. T : Preheating of fuel. t : Dimensions of combustion chamber. : Turbulence generation systems.
The Three Ts & One S Practice TechnologyTimeTemperatureTurbulenceSize StokerlargeMediumLowBig PulverizedShortHighMediumTiny CycloneShort+V HighHighMedium Fluid BedMediumLowHighMedium Size the Coal and Add the Air !!!
Boiler Furnace Structurally boiler furnace consists of the combustion space surrounded by water walls. The furnace is designed to perform two functions simultaneously, namely: Release of the chemical energy of fuel by combustion The first task of combustion technology is to burn the fuel efficiently and steadily, to consume controlled excess air (as little as possible), To generate a flame with controlled shape which will generate lowest amount of pollutants. Transfer of heat from the furnace to the working fluid inside the water walls. The important task of furnace heat removal is to produce a controlled Furnace Exit Gas Temperature (FEGT). FEGT is an important aspect of boiler safety.