Fossil Fuel Power Station
Fossil fuel power stations have rotating machinery to convert the heat energy of combustioninto mechanical energy, which then operates an electrical generator. The prime mover may be a steam turbine, a gas turbine or, in small plants, a reciprocating internal combustionengine. All plants use the energy extracted from expanding gas - steam or combustion gases. A very few MHD generators have been built which directly convert the …show more content…
Coal-fired power plants provide about 46% of consumed electricity in the United States. This is the Castle Gate Plant near Helper, Utah.
Coal is delivered by highway truck, rail, barge, collier ship or coal slurry pipeline. Some plants are even built near coal mines and coal is delivered by conveyors. A large coaltrain called a "unit train" may be two kilometers (over a mile) long, containing 130-140 cars with 100 short tons of coal in each one, for a total load of over 15,000 tons. A large plant under full load requires at least one coal delivery this size every day. Plants may get as many as three to five trains a day, especially in "peak season" during the hottest summer or coldest winter months (depending on local climate) when power consumption is high. A large thermal power plant such as the one in Nanticoke, Ontario stores several million metric tons of coal for winter use when the lakes are frozen.
Modern unloaders use rotary dump devices, which eliminate problems with coal freezing in bottom dump cars. The unloader includes a train positioner arm that pulls the entire train to position each car over a coal hopper. The dumper clamps an individual car against a platform that swivels the car upside down to dump the coal. Swiveling couplers enable the entire operation to occur while the cars are still coupled together. Unloading a unit train takes about three hours.
Shorter trains may use railcars with an "air-dump", which relies on air pressure from the