In the steam generation flow diagram above, where the gas or oil or coal get mix
ID: 2292396 • Letter: I
Question
In the steam generation flow diagram above, where the gas or oil or coal get mixed with the air?
Where the steam is generated?
What does superheater do and what does Reheater do?
Why there is high-pressure turbine and low-pressure turbine?
How the steam be cooled?
What device they used to filter the waste and absorb the SO2?
What is the function of cooling tower?
Explain the operating principle of a steam turbine.
Electrical Power To Switchyard Superheater Flue Gas Boundary 2 High- Pressure Turbine Low Pressure Turbine tea o Drum o Exhaust Generator Water Walls Reheater Steam Condenser Burner Feedwater pump Flue gas stack Fuel Economizer Water heate Fresh Cooling Water Induceo draft fan Header ir ir heater SO2 Scrubber Ash handling Precipitator/ Fabric filter Air Air Forced draft fan Fuel pump FuelExplanation / Answer
1. In the steam generation flow diagram above, where the gas or oil or coal get mixed with the air?Where the steam is generated?
In this flow diagram the gas or oil or coal get mixed with air in the burner and the fuel will burn in that burner or boiler and it will raise the temperature and pressure of that air and the steam is produced in the boiler.This boiler construction is of two types.
a) Water tube boiler : The water will be circulated through the pipes kept in the boiler arc furnace or water tubes are kept in the arc furnace.
b) Fire tube boiler: The water will be circulated on the outer parts of pipes while fire is flowing in the pipes
2. What does superheater do? what does Reheater do?
Super heater is next to the boiler. To utilise heat energy of flue gases more effectively , the steam produced in the boiler will be sent into the super heater. The steam coming out from super heater will have high pressure and temperature higher than the boiler steam pressure and temperature.
Reheater :The exahsted steam from high pressure turbine will be sent into reheater to increase the steam & pressure.
3. Why there is high-pressure turbine (HPT) and low-pressure turbine( LPT)?
Multistage turbines : A no.of turbines (HPT, IPT(INTERMEDIATE PRESSURE TURBINE) , LPT) connected in cascade and exhasted steam from one turbine will act as input steam for other turbine. ( the steam coming out from HPT will have less pressure than the input steam to HPT , so LPT is used after HPT ). By using this , the steam energy efficiently converted into mechanical energy.
4. How the steam be cooled? What is the function of cooling tower??
The exahsted steam from low pressure turbine (LPT) sent into condenser and there the steam will converted into water. In the condenser cool water is pumped into it and it will flow on the tubes in which the low pressure steam is flowing. In this way the steam is cooled and the hot water which is produced in this process will sent into the cooling tower and then to the pond. If the hot water is directly into it will cause danger to the aquatic animals and to the atmosphere so it is processed through heat rejection device ,which is cooling tower.
5. What device they used to filter the waste and absorb the SO2?
1. Lime stone, dolamite will be added to coal before burning to reduce SOx, NOx from flue gases.
2. Electrostati precipitators(ESP) removes the dust particles and ash particles from flue gases by attracting them(ionised particles). ESP operates for d.c voltage of 30kV. ESP efficiency is 99%.
Several technologies have been developed to control SO2emission during combustion, however only few of them have been commercialized. The most developed are the fluidized bed combustion and integrated gasification combined cycle (IGCC).
6. Explain the operating principle of a steam turbine.
When the high pressure steam is incident on the turbine blades then they will rotate at high speed such that the kinetic energy of the steam is converted into mechanical energy. When this turbine is coupled with the shaft of the generator, the mechanical energy will be converted into electrical energy.
Principle of steam turbine is to convert kinetic energy of steam into mechanical energy.
6. Explain the operating principle of a steam turbine.
When the high pressure steam is incident on the turbine blades then they will rotate at high speed such that the kinetic energy of the steam is converted into mechanical energy. When this turbine is coupled with the shaft of the generator, the mechanical energy will be converted into electrical energy.
Principle of steam turbine is to convert kinetic energy of steam into mechanical energy.