Thermal design of steam boiler is the process to design furnace, heat transfer surface, control steam and water temperature, and select suitable burner or without burner method. Design furnace is calculation process to reach the best size and configuration of furnace to perform combustion completely. Furnace can be designed based on some parameters; wall construction, pressure, heat transfer, waste heat recovery, fuel and firing methods.
After design furnace, the next step to design thermal in steam boiler is calculate heat transfer surface in wall tubes, superheater, reheater, economizer, and air heater. The optimum heat transfer is the objective of this step to determine the requirement a number of tubes needed for the listed pressure parts above.
After design furnace and heat transfer surface, the next important step is control water and steam temperature. Control water temperature is used in economizer while steam temperature is performed in steam outlet temperature in superheater and reheater. Control steam temperature is responsible by desuperheater or attemperator.
Then design burner equipment for selected fuel (gas, oil or pulverized coal) and design without burner if steam boiler use stoker firing is the other necessary step to do thermal design process.