Various Plants used for Generation of Electric Power : Hydroelectric, Nuclear and Thermal Energy Plants Parts & Working
2.Nuclear power plants.
3.Thermal power plant.
The hydro power plant converts the energy obtained from the running water into electricity.These power stations are suitable for places with sufficient water resources.
The layout of a typical hydro power plant and a description of all the main parts are given below.
The basic requirement of the hydro power plant is a good reservoir in which a large amount of water is stored during the flood season and used during the dry season.
The reservoir was built by building a dam on the river.The function of the dam is to increase the height of the water level, which in turn increases the capacity of the reservoir.The dam also helps to increase the work head of the power plant.
The pipe between the surge tank and the power room is called the Pen Bar.A pen is a conductor that draws water from a reservoir to a power station.Steel, pipes are usually used.Penstocks are usually equipped with head gates at the entrance and can be closed when repairing penstocks.
The valve chamber contains the valve that controls the flow of water into the Power Chamber under normal circumstances.When the pressure pipe burst, the automatic isolation valve in the valve chamber cut off the water supply.
The surge tank is a small additional storage facility near the power company.This is required when there is a considerable distance between the power company and the reservoir.When the distance is moreThe uniform water intake of the power station can cause the pressure pipe to burst.In the absence of a surge tank, excess water rushes at the low end, causing the pressure pipe to burst.However, in the presence of surge tanks, they can be used whenever there is a lack of water.Therefore, the surge tank acts as a shock absorber or a pressure regulator tank.
The power company where the turbines and generators are located.The turbine rotates the turbine shaft, and the turbine shaft rotates the generator shaft coupled with the turbine shaft.Therefore, the turbine converts the hydraulic energy to mechanical energy, and the generator converts the mechanical energy to electrical energy.Power companies are usually at the bottom of the dam.
It also provides irrigation and flood control services.
No fuel is needed.
Short start time.
The cost of power generation is very low.
It uses simple technology.
Generally speaking, the life of the hydro power plant is longer.
Construction costs are high.
Large area required for installation.
This has affected the ecological balance of the region.
This generation depends on the weather.
If the nuclear fission reaction occurs in a controlled manner, then the energy released can be used for constructive purposes such as power generation.A device or device used for fission reactions under controlled conditions is called a nuclear reactor.The energy generated in a controlled manner can be used to generate steam, which can run the turbine and generate electricity.This arrangement is used in nuclear power plants to generate electricity.
The schematic diagram and main parts related to the nuclear power plant are given below.
Nuclear fission reactions occur in nuclear reactors.The condensed fuel is used in the reactor in the form of a rod.To control the fission reaction, a movable Rod made of cadmium or boron is suspended between the fuel rods.These rods control the fission process by absorbing excess neutrons.These are called control rods.Moderator is a substance used to slow down fast-moving neutrons so that they are easily captured by fuel and cause further fission reactions.Graphite or heavy water are usually used as moderators.
To protect the surroundings from radiation, the nuclear reactor is enclosed in a thick, large, concrete shield.
To absorb the heat generated during fission, cycle a liquid called coolant in the reactor core and heat exchanger.Heavy water is usually used as coolant.In a heat exchanger, steam is produced using heat transferred from the reactor.A large amount of heat generated during U-Nuclear fission235 is used to convert water into steam.The steam is then used to drive the turbine connected to the generator.Electricity is generated in this way.
Radiation hazards are a big problem.
The disposal of radio-operated waste creates difficulties.
The initial cost is high.
Fuel is expensive and not rich.
Its operation requires high technical knowledge.
Electricity generation has nothing to do with weather conditions.
The area required for installation is small.
The amount of fuel involved is small.
Less pollution than thermal power plants.
Thermal power plays a central role in power supply, and we are working hard to develop more efficient power generation technologies.
In a thermal power plant, steam is generated and used to rotate the turbine running the generator.Conventional thermal power plants use coal, oil, or natural gas as fuel to boil water to produce steam.There are three main types of thermal power plants. they are the following.
Steam turbine power plant.
Gas turbine power plant.
Diesel engine power plant.
Steam turbine power plants use coal, oil or natural gas as fuel, while gas turbines use only oil or natural gas as fuel.Diesel is used as fuel in diesel power plants.
Steam Power Plant facilities are a means of generating electricity using the expanded power of steam.The fuel is burned inside the boiler to heat the water and generate steam.This steam is then used to drive the turbine and, in turn, to drive the generator to generate electricity.This steam is suitable for the use of thermal energy at a relatively low temperature (below 600 degrees Celsius.The steam coming out of the turbine condenses into water and is recycled.
In order to improve the efficiency of the steam power unit, functional components such as super heater and coal-saving device are added.Also included in the factory.The schematic diagram and different parts are shown below.
In this system, the coal from the coal storage warehouse is delivered to the boiler through the coal handling equipment to generate steam.Ash generated by ash storage
The air is supplied to the combustion chamber of the boiler through the induced draft fan.Exhaust gas with sufficient heat and Ash passes through the air heater and then enters the boiler.The flue gas coming out of the boiler is about 1000 degrees Celsius.This hot air passes through different stages such as super heater, coal saver, air pre-Heater, in the end, it was releasedxa0Out of the chimney
The boiler burns the fuel transferred from the tank and uses the resulting heat to convert the water into steam.There are tens of thousands of water pipes in the boiler.When the combustion starts, the temperature inside the boiler rises to between 1,100 and 1,500 degrees Celsius, and the water inside the tube becomes high temperature and high pressure steam, which is transported to the steam turbine.The correct proportion of coal and air is sent to the boiler room for combustion.The water is supplied to the boiler through the boiler water supply pump.The water is converted into steam in the boiler room.
The super heater is a heat exchanger that increases the steam pressure and eliminates moisture in the steam by using the high temperature flue gas of the boiler.
The water in the condenser is passed to the coal Saver, which heats the water and sends the water to the boiler.
Air pre-Heater as heat exchanger.It uses the heat from the flue gas to heat the air from the intake system.Then send the heated air to the boiler.This ensures proper combustion and helps to improve the overall efficiency of the power plant.
The steam generated in the boiler is delivered to the steam turbine through the super heater.Using a condenser and cooling tower device, the steam flowing out of the turbine is condensed into water.Condensate can be recovered throughout the process.The feed pump delivers water to the boiler through a coal-saving device.The steam is cooled by seawater in the condenser, restored to water, and then returned to the boiler for reuse.The cycle of this water, the cycle of steam to water repeated over and over again.
The steam generated in the boiler is delivered to the steam turbine through the super heater.This steam drives the turbine.Steam rotates turbine blades at a high speed of 3,000 rpm.The turbine converts thermal energy into thermal energy.This will be directly connected to the generator rotation of the turbine.The alternator converts this mechanical energy into electrical energy.
Gas turbines use natural gas, oil, etc.as fuel.There are two types of gas turbine cycle: Open cycle and joint cycle.In an open cycle, the fuel is burned in compressed air and the resulting exhaust gas is used to drive the gas turbine.
The high flow rate of the turbine plus a relatively moderate pressure ratio requires the use of a rotary compressor.There are two types.Centrifugal compressor and axial compressor.Axial-flow compressors are commonly used in gas turbines due to their higher efficiency (90-95%), although they are not so strong in structure, there is a lower pressure ratio at each compression stage.Under atmospheric pressure, the air is sucked in by the compressor through the air filter.The blade is made from the air foil part and is set in a way that rotates the space-time gas to move towards the rear edge of the blade.Diffusion occurs when air enters the next set of moving blades fixed on the stator.In each successive stage, compression occurs and the air is available at high pressure at the output of the compressor.
: The exhaust gas from the turbine has a large amount of heat and can be used to heat the compressed air used to burn in the combustion chamber.The device to carry out this heat exchange is called a regeneration device.It consists of a nest of tubes in the shell.The exhaust gas flows inside the tube, while the air flows outside the tube inside the shell in the opposite direction and is heated.
At a high pressure from the recycler, the air is delivered to the combustion chamber, where it is heated by the combustion oil.At high pressure, the oil is injected into the chamber through the burner to ensure its atomization and mixing with the air.The temperature of the chamber may rise to 3000 degrees Fahrenheit, and the combustion gas will cool to about 1500 degrees Fahrenheit before it is delivered to the gas turbine.
The gas mixture under high temperature and high pressure moves from the combustion chamber to the gas turbine, where it expands and delivers mechanical energy.The temperature of the turbine exhaust gas is about 900 degrees Fahrenheit.Gas turbines are usually axial.The basic requirements of the turbine are light weight, long life and high efficiency.
The gas turbine is connected to the AC generator.The mechanical energy of the gas turbine is converted into electrical energy through an AC generator.
Before supplying compressed air to the turbine, the compressor must be driven.In the case of an isolated system or conventional power supply, the motor is powered by a battery.In the combined cycle power plant, hot gas is also used to generate steam, and there is a steam turbine in addition to the gas turbine.As energy utilization is better in this case, overall efficiency is greatly improved.
Diesel is used as fuel in a diesel power plant.The block diagram and different parts of the diesel power plant are explained below.
This is a major component of a diesel power plant that develops electricity.They may be 4-stroke or 2-stroke engines.The 4-stroke engine has lower fuel consumption than the 2-stroke, more flexibility, better sweeping effect and higher efficiency.To make the engine more compact, the cylinders are arranged in V shape.6 to 8 cylinders are commonly used.The speed is in the range of 500-1000 rpm.The diesel engine is pressure-fired.The size of the diesel engine ranges from 75 KW to 3750 KW.
The function of the air filter is to remove dust from the air taken away by the engine.The role of the supercharger is to increase the air pressure supplied to the engine to increase the power of the engine.The supercharger is driven by the engine.
The silencer and connecting pipes are included.A silencer is required between the engine and the intake system, as noise may be passed back to external air through the intake system.The temperature of the exhaust gas is very high, and the heat is used to heat the oil or air supplied to the engine.
This includes a storage tank, fuel pump, filter and heater.The fuel is supplied according to the load of the factory.A filter is provided to remove suspended impurities.Especially in winter, the heater is required to heat the oil.
Oil pump, fuel tank, filter, cooler and connecting pipe are included.The role of the lubrication system is to reduce the friction of the moving parts and reduce the wear of the engine parts.The life and efficiency of the engine depend largely on the lubrication system.
Compressed air tanks are included.The function of this system is to start the engine from the cold by providing compressed air.
Their function is to keep the speed of the engine constant, regardless of the load on the plant.This is achieved by changing the fuel supply of the engine according to the load.
The generator used by the diesel power plant has a rotating magnetic field, a convex structure, a speed of 214 to 1000 rpm and a speed of 25-5000 kVA at 0.8 Power factor lag.The generator is directly connected to the diesel engine.They are equipped with voltage regulators to allow voltage regulation.The excitation is usually provided from the DC exciter machine at a voltage of 115 to 230 V, usually coupled to the engine shaft through a belt.