What are the roles of power plants and substations? What are the types of each?

In power plants and transformers, the DC system provides a reliable DC power source for control signals, relay protection, automation, circuit breaker tripping operation circuits, and so on under normal conditions.

Steam system - - after superheating high-pressure high-temperature steam is initially sent to the high-pressure turbine, so that it rotates, and then through the re-heater, make up for the thermal energy, in order, into the medium-pressure turbine and the low-pressure turbine, so that all the thermal energy is consumed, and then sent to the condenser, back to the raw water, the water through the heater, the economizer, and the cycle.

Cooling Water System--The cooling water in the cooling tower is supplied by the river, well, sea and tap water system, and the cooling water through the condenser returns to the cooling tower for cooling.

Conventional power generation refers to coal-fired power plants, coal-fired thermal power plants flow chart

Combustion gas system──coal: from the automatic conveyor belt - funnels, meters into the mill, crushed, and high-temperature steam in a certain proportion of the mix, and then blown by the nozzle into the and then blown into the boiler by the nozzle for combustion.

The circulating pure water in the whole drain which forms the lining of the furnace wall is heated and boils to produce steam. After combustion, the ash falls into the ash outlet and is discharged. The flue gas in the flue sails to the superheater, and then heated by the steam in the heater to improve the boiler in the reheat economizer, with warm water and air heater for combustion gas, and finally discharged to the atmosphere after precipitation dust collector and chimney.