Experiment No.: 3
Identify the routine maintenance parts of the coal fired thermal power plant after watching a video programme.
To identify different parts of coal fired thermal power plant.
Some important parts of coal fired thermal power plant are shown below.
- Coal storage
- Ash storage
- Cooling tower
- Coal storage: In a coal based thermal power plant coal is transported from coal mine to the generating station. The coal storage is either dead storage or live storage. Dead storage is generally 40 days backup coal storage which is used when coal supply is unavailable. Live storage is a raw coal bunker in boiler house.
- Maintenance: Coal bin which is used for storage of coal should cleaned after it gets empty. It should be vernish once in a year to increase it’s life span.
- Ash Storage: Ash storage refers to the method of collection, conveying, interim storage and load out of various types of ash residue left over from solid fuel combustion process. The most common types of ash resulting from the combustion of coal, wood and other solid fuels, bottom ash, bed ash and fly ash.
- Maintenance: Ash conveyer or belt should be cleaned regularly to keep it in working condition. Ash storage tank should be cleaned regularly to create space for new ash coming from boiler after combustion.
- Boiler: A boiler is a closed vessel in which fluid is heated. The fluid doesnot necesserily boil. The heated or vaporised fluid exists the boiler for use in various processes or heating application including water heating, central heating, boiler based power generation, cooking and sanitation.
- Maintenance: Good quality of coal should be used for increasing efficiency of boiler. It should be cleaned regularly and cleaned the water tubes on regular basis.
- Superheater: A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbine for electricity generation, steam engines and in process such as steam reforming. Superheater increase the thermal efficiency of the steam engine, and have been widely adopted.
- Maintenance: Superheater can be maintened properly by keeping steam temperature constant for minimizing thermal stress on the boiler and turbine.
- Economiser: Economiser is a mechanical device intended to reduce energy consumption or to perform useful function such as preheating a fluid. The term economiser is used for other purpose as well as boiler, power plant, heating, refrigertation, ventilation and air conditioning uses. Its function is to make use of heat energy of flue gases to increase the inlet water to be fed to boiler. The economiser is also called as heat exchanger.
- Maintenance: At least twice a year, perform a facility walk through to inspect and repair economiser equipment. At minimum check, corrosion and deposit of dirt and moisture that could cause the outside air damper.
- Turbine: It is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating electrical power when combineds with a generator. A turbine is a turbomachine with at least one moving fluid act on the blades attached.
- Maintenance: Ensure proper steam quality is delivered to the turbine. Proper expansion compensation supply and exhaust line are sized properly. Steam piping needs to be properly supported.
- Alternator: An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternator uses a rotating armature with a stationary magnetic field is used.
- Maintenance: Alternator shaft should be cleaned and greased on monthly basis to increase the efficiency of alternator. Alternator wiring and winding should also be inspected on monthly or yearly basis.
- Condenser: It is an important component in the thermal power system. It is located near turbine to receive exhaust steam from turbine. In the condenser, exhaust pressure of steam is decrease below the atmospheric pressure. Condenser condense the steam. It is cooled by the cold water and the same is fed back to the boiler through economiser. So, this is good and pure feed water to the boiler. This helps in reducing the capacity of water softening plant, also it remove air and non-condensable gases from steam when passes through condenser.
- Maintenance: From the low pressure turbine the exhaust steam enters the shell the steam is cooled and converted to water over the tubes of condenser.
- Cooling tower: A cooling tower is a specialized heat exchanger in which air and water are brought into direct contact with each other in order to reduce the water’s temperature. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower.
- Maintenance: Scale deposits should be removed, to ensure proper air flow, to clean tubes of cooling tower, to inspect the water pump, to treat water regularly. These activities should be carried out for maintening cooling tower.
- Chimney: The function of the chimney is to discharge flue gases to the atmosphere at such a height and velocity that the concentration of pollutant, such as Sulphur dioxide, is kept within acceptable limit at ground level. After leaving the top of the chimney, the gases are carried higher by their own buoyancy compared to the surrounding air and the momentum of the flue gases emitted.
- Maintenance: Chimney should be maintained by smokestack repairing, resurfacing and pointing. Adjusting chimney far distance ash should be removed.
In this way we identify the routine maintenance parts of coal fired thermal power plant.