FREE ESSAY ON STEAM ENGINE

STEAM ENGINE

The steam engine was an engine powered by steam. It provided an important source of power
independently. The steam engine played a major role in manufacturing and transportation
during the Industrial Revolution. The challenge of improving the steam engine was the
beginning of the science of thermodynamics.
The steam engine was a very important invention. "Steam can be made at any time simply by
boiling water, so it is more dependable than wind or water energy" (Norbeck 34-36). The
heating and cooling of steam in cylinder causes pistons to move up and down. The simplest
of a steam engine is used as a boiler. This was a common household heating system. The
efficiency of the steam engine was very low; there fore they were later replaced by steam
turbines. The first piston engine was invented in 1690 by a French inventor named Denis
Papin and was used for pumping water. "Why not find a way to use heat energy" (Garrat
12). It had a single cylinder that operated as a boiler; a small amount of water was
added and heated to form steam. The steam raised the piston in the cylinder, after it was
raised the heat was removed, the steam condensed and the air pressure on the upper side
forced the piston down. In 1705 Thomas Newcomen invented the first practical steam
engine. 
Steam operates the engine by a slide directing steam from on one side of the piston to
the other. As the piston moves, the piston rod turns the flywheel half a turn. The steam
engine doesn't create power, I t uses steam to change heat energy released by burning
fuel into mechanical energy. 
Steam engines are considered to be external combustion engine because, the fuel is burned
outside of the cylinders. An example of internal combustion engine is an automobile. The
power is provided by the rapid burning of gasoline inside the cylinders, which is ignited
by the spark plug. The explosion inside the cylinder wall causes the pistion to go down
and turning a shaft.
Thomas Newcomen invented the first steam engine in 1705 although it wasn't very
efficient; it was used for pumping water for coal mines. James Watt improved Newcomen's
engine in the 1760's. He produced the first type of double acting engine. "One after
another hand operations were replaced by machines" (Lipkin).
In a compound engine, steam in high pressure is used in one cylinder and then, after it
has expanded and lessened in pressure, it is piped to another cylinder, in which it
expands further. The first compound engine used a two-cylinder type but later other types
of compound engines used triple and even quadruple cylinders. The advantage of
compounding two or more cylinders is that less energy is lost in heating the cylinder
walls, as a result, the engine is more efficient. 
Further improvements to the steam engine lead to the uniflow engine. The piston itself is
a valve, and the cylinder remains at a constant temperature while operating. In the
uniflow engine steam moves in only one direction, it has two inlet ports and one outlet
port. This was a large engine, and was used mainly in big operations; it also was a very
expensive engine compared to other engines. This type of engine was a very efficient use
of high-pressure steam. 
Steam turbines produce a rotary motion; it works the same way as a water turbine, except
its energy comes from expanding steam. It turns a set of main rotating blades on a wheel.
Steam turbines rotate very fast and have no vibrations, unlike the back and forth motion
of pistons. Steam engines work great in steam ships, and electric power plants.
The flywheel turns at the end of the piston shaft. It was made of heavy metal cast-iron,
so it helped eliminate power surges to the generator and, also provides a uniform flow of
power.
Since the steam engine was invented we have came along way with engines. Now we are
making power by nuclear power plants and things have become much more industrialized. We
are always looking for new ideas and ways to improve energy efficiency.