Though each plant is unique in itself in terms of specific features and functionalities, still there is a broad outline to which all thermal power plants confirm to and in this article we will study about the general layout of a typical power plant.
There are four main circuits in any thermal power plant and these are
- Coal & Ash Circuit – this circuit deals mainly with feeding the boiler with coal for combustion purposes and taking care of the ash that is generated during the combustion process and includes equipment and paraphernalia that is used to handle the transfer and storage of coal and ash.
- Air & Gas Circuit – we know that air is one of the main components of the fire triangle and hence necessary for combustion. Since lots of coal is burnt inside the boiler it needs a sufficient quantity of air which is supplied using either forced draught or induced draught fans. The exhaust gases from the combustion are in turn used to heat the ingoing air through a heat exchanger before being let off in the atmosphere. The equipment which handles all these processes fall under this circuit.
- Feed Water & Steam Circuit – this section deals with supplying of steam generated from the boiler to the turbines and to handle the outgoing steam from the turbine by cooling it to form water in the condenser so that it can be reused in the boiler plus making good any losses due to evaporation etc.
- Cooling Water Circuit – this part of the thermal power plant deals with handling of the cooling water required in the system. Since the amount of water required to cool the outgoing steam from the boiler is substantial, it is either taken from a nearby water source such as a river, or it is done through evaporation if the quantity of cooling water available is limited.
The above breakdown of the plant would give you a clear idea about the components of the plant but a complete picture shown below would be more useful in getting an idea how these circuits are integrated together to form the complete power plant.
click to enlarge
