In this article, I will share with you the overall view of a steam power plant, the main components and its working principle.
Introduction To Steam Power Plant
Steam power plant mainly depends on steam generated from water to drive the steam turbines and the steam generated drives the steam turbines providing mechanical energy that is to be converted to electricity by the generators.
The process it’s not as seem as it seems, there is so much that goes on into this process of energy generation from a steam power plant.
The steam power plant utilizes lots of water since it’s the main factor of energy generation after the fuel.
Don’t forget that a steam power plant needs a large quantity of coal to be effective.
The steam power plants are suitable in places where there is an abundance of coal.
This will make it easier for the power plant to acquire the fuel and utilise it without much cost.
Fuel is one of the supplies that tend to increase the operation costs of power plants.
Taking away the transportation factor reduces the operation cost of the steam power plant by a bit.
You might like this: Factors To Be Considered While Installing A New Power Plant
One of the reasons why steam is preferred is that it’s driven from water which is always available in large quantities, the steam does not react with most of the materials used in the power plant and it’s stable at the required temperature.
Steam power plants are suitable since their capacity can be easily altered which is very different when you compare it to a nuclear power plant.
You might like this: Factors Affecting Power Plant Capacity
It can supply varying loads and large base loads as long as its generating units and other components can handle the electrical energy that will be generated.
You might like this: Properties Of Coal Selected For Steam Power Plants
Essential Steam Power Plant Equipment
A steam power plant needs the following pieces of equipment for it to be functional;
A furnace; it’s needed to burn the fuel that is to generate the heat energy to heat the water to produce high-pressure steam.
It’s the steam that will drive the turbines.
If you want to learn more about the firing systems and the burning equipment used in steam power plant then you should read the article below.
You might like this: Overfeed & Underfeed Stokers: Classification and Working Principles
Steam generator or a boiler: for the steam to be generated these pieces of equipment are needed.
The boiler in most cases is the piece of equipment that is widely used in many steam power plants since they are designed to operate long-term.
But steam generators are a good choice if one has limited space, the budget of installation is low and a quick start-up is required.
The drawback of using steam generators is that their capacities are lower compared to full-scale industrial boilers.
You might like this: Boilers: Components, Types & Working Principle
Steam turbine or engine; it’s needed to utilize the steam energy to perform work.
The high-pressure steam is directed to the steam turbine or engine where it gives up its heat energy and pressure to provide the mechanical energy needed to generate the electrical power.
Generators; are needed to convert the mechanical energy from the steam turbine or engine into electrical energy.
Without these pieces of equipment, there is no way of generating electrical energy.
The generators can be more than two depending on the load that needs to be generated.
The above equipment in the steam power plants are essential ones, but more components are installed.
Other components installed in a steam power plant are as follows;
- Economizer.
- Condenser.
- Chimney.
- Cooling tower.
- Pumps.
- Steam distribution lines.
- Piping system to supply boiler feed water.
- Control panels.
Working Principle Of Steam Power Plant
The working principle of a steam power plant is quite simple as it involves the conversion of mechanical energy into electrical energy via the generators.
It doesn’t involve so many complicated processes.
The functionality of the steam power plant mainly depends on the steam being generated, the work done by the steam turbines or engines and the generator connected to the steam turbine or engine.
This is how a steam power plant works; the fuel is fed into the furnace where it’s burnt to produce heat energy required to heat the water in the boiler to generate high-pressure steam.
A boiler or a steam generator can be used to generate high-pressure steam. That is something you have to keep in mind.
The high-pressure steam produced by the boiler or steam generator is taken to the superheater when it’s further heated.
The superheater increases the efficiency of the steam by supercharging it and dries up the steam which minimizes corrosion of the steam distribution lines and the steam turbine blades.
After that, the superheated steam with high pressure and temperature is directed to the steam turbine.
This steam of high temperature and pressure drives the blades in the turbine as it passes past them leaving behind its energy.
This energy is what drives the steam turbine blades producing mechanical energy that is needed to generate electrical energy.
The steam turbines are connected to the generator that converts the mechanical energy into electrical energy.
After the steam has been used up in the steam turbine to drive the blades it passes through a condenser which maintains the low pressure of the steam at the exhaust of the turbine.
The condensate (hot water coming from the condenser) will be conveyed to the cooling tower via the piping system to be cooled and recirculated again in the condenser.
You might like this: Cooling Ponds, Cooling Towers: Components And Working Principles
This ensures that there is a sparing use of water in the steam power plant.
The steam is not entirely used in the turbine as some of the steam will escape the steam turbine; this steam is called bled steam.
The bled steam is sent to low-pressure and high-pressure water heaters to be charged again and it can be reused to drive the steam turbines or it can be used for other purposes in the steam power plant.
This is to ensure that heat losses in the steam power plant are minimized to increase the efficiency of the plant.
You might like this: Type Of Heat Losses In a Steam Plant (+How To Minimize Them)
The air used in the furnace is taken from the atmosphere and then passes through air preheaters where it’s heated first giving it initial energy that facilitates ignition and proper combustion of the fuel.
You might like this: Air Preheaters in Steam Boilers: Function, Types and Working Principles
The air preheaters use the flue gas temperature to heat up the air used in the furnace.
Read the article above to know more about the working principle of air preheaters.
The flue gasses from the furnace pass through the air preheaters, superheaters and over the boiler to minimize the waste heat and are treated before it’s released into the atmosphere.
To control the gaseous pollutants in the flue gasses, treatment has to be done to ensure the air taken to the atmosphere is not harmful.
You might like this: Methods Of Controlling Gaseous Pollutants (Ultimate Guide)
The process is just simple as I have described it. There are a lot of things you need to learn if you don’t know anything about boilers, cooling towers, condensers, superheaters etc.
This knowledge will help you understand how the other auxiliaries installed in the steam power plant help in electrical energy generation.
I already wrote articles about these components if you want to get familiar with the overall processes that happen in a steam power plant.
Check the links to each of the specific things you want to learn more about.
Lastly…
The steam power plant is just simply in its operation and that is what makes it great since even those who are not skilled enough can operate them.
But when you talk about a nuclear power plant, you need people who have expertise in that area to be able to run the plant effectively.
The initial cost of the steam power plant tends to be quite higher but the good thing is that its operation cost is pretty considerably low.
It has to run to its highest possible load factor to be able to provide the best efficiency that the plant can.
Thanks for reading, if you have any questions about what I have shared just leave a comment. See you in my next article.
Related articles to check.
