RAI SAHEB BHANWAR SINGH COLLEGE NASRULLAGANJ

1. Steam EnginesSteam Engines
Bharti RajputBharti Rajput

2. History of Steam EngineHistory of Steam Engine
 Inventors used experimental devices, such as the rudimentaryInventors used experimental devices, such as the rudimentary
steam turbinesteam turbine device described bydevice described by Taqi al-DinTaqi al-Din in 1551 andin 1551 and
Giovanni BrancaGiovanni Branca in 1629, to demonstrate the properties of steam.in 1629, to demonstrate the properties of steam.
 The first practical steam-powered 'engine' was a water pump,The first practical steam-powered 'engine' was a water pump,
developed in 1698 bydeveloped in 1698 by Thomas SaveryThomas Savery. It proved only to have a. It proved only to have a
limited lift height and was prone tolimited lift height and was prone to boiler explosionsboiler explosions, but it still, but it still
received some use for mines andreceived some use for mines and pumping stationspumping stations..
 The first commercially successful engine, theThe first commercially successful engine, the atmospheric engineatmospheric engine,,
invented byinvented by Thomas NewcomenThomas Newcomen did not appear until 1712.did not appear until 1712.
Newcomen's engine was relatively inefficient, and in most casesNewcomen's engine was relatively inefficient, and in most cases
was only used for pumping water.was only used for pumping water.

3. History of Steam EngineHistory of Steam Engine
 James WattJames Watt developed an improved version of Newcomen'sdeveloped an improved version of Newcomen's
engine between 1763 and 1775 which used 75% less coal thanengine between 1763 and 1775 which used 75% less coal than
Newcomen's, and was hence much cheaper to run. WattNewcomen's, and was hence much cheaper to run. Watt
proceeded to develop his engine further, modifying it to provideproceeded to develop his engine further, modifying it to provide
a rotary motion suitable for driving factory machinery.a rotary motion suitable for driving factory machinery.
 Early engines were "atmospheric", meaning that they wereEarly engines were "atmospheric", meaning that they were
powered by thepowered by the vacuumvacuum generated bygenerated by condensingcondensing steam insteadsteam instead
of theof the pressurepressure of expanding steam.of expanding steam. CylindersCylinders had to be large, ashad to be large, as
the only usable force acting on them wasthe only usable force acting on them was atmospheric pressureatmospheric pressure..
Steam was only used to compensate for the atmosphere allowingSteam was only used to compensate for the atmosphere allowing
the piston to move back to its starting position. Even ifthe piston to move back to its starting position. Even if
pressured steam had been available, it could not do any workpressured steam had been available, it could not do any work
(push) against the(push) against the chainchain connecting the piston to the beam.connecting the piston to the beam.

4. Early Watt Steam pumping engine.Early Watt Steam pumping engine.

5. History of Steam EnginesHistory of Steam Engines
 Around 1800,Around 1800, Richard TrevithickRichard Trevithick introduced engines using high-introduced engines using high-
pressure steam. These were much more powerful than previouspressure steam. These were much more powerful than previous
engines and could be made small enough for transportengines and could be made small enough for transport
applications.applications.
 Thereafter, technological developments and improvements inThereafter, technological developments and improvements in
manufacturing techniques (partly brought about by the adoptionmanufacturing techniques (partly brought about by the adoption
of the steam engine as a power source) resulted in the design ofof the steam engine as a power source) resulted in the design of
more efficient engines that could be smaller, faster, or moremore efficient engines that could be smaller, faster, or more
powerful, depending on the intended application.powerful, depending on the intended application.
 Steam engines remained the dominant source of power well intoSteam engines remained the dominant source of power well into
the 20th century, when advances in the design ofthe 20th century, when advances in the design of electric motorselectric motors
andand internal combustion enginesinternal combustion engines gradually resulted in the vastgradually resulted in the vast
majority of reciprocating steam engines being replaced inmajority of reciprocating steam engines being replaced in
commercial usage, and the ascendancy of steam turbines incommercial usage, and the ascendancy of steam turbines in
power generation.power generation.

6. Rankine CycleRankine Cycle

7. Rankine CycleRankine Cycle
 Process 1-2Process 1-2: The working fluid is pumped from low to high pressure, as the fluid is a liquid at this: The working fluid is pumped from low to high pressure, as the fluid is a liquid at this
stage the pump requires little input energy.stage the pump requires little input energy.
 Process 2-3Process 2-3: The high pressure liquid enters a boiler where it is heated at constant pressure by an: The high pressure liquid enters a boiler where it is heated at constant pressure by an
external heat source to become a dry saturated vapor.external heat source to become a dry saturated vapor.
 Process 3-4Process 3-4: The dry saturated vapor expands through a: The dry saturated vapor expands through a turbineturbine, generating power. This, generating power. This
decreases the temperature and pressure of the vapor, and some condensation may occur.decreases the temperature and pressure of the vapor, and some condensation may occur.
 Process 4-1Process 4-1: The wet vapor then enters a: The wet vapor then enters a condensercondenser where it is condensed at a constant pressurewhere it is condensed at a constant pressure
and temperature to become a saturated liquid. The pressure and temperature of the condenser isand temperature to become a saturated liquid. The pressure and temperature of the condenser is
fixed by the temperature of the cooling coils as the fluid is undergoing a phase-change.fixed by the temperature of the cooling coils as the fluid is undergoing a phase-change.

8. Basic operation of a simple reciprocatingBasic operation of a simple reciprocating
steam enginesteam engine
 Heat is obtained from fuel burnt in a closed fireboxHeat is obtained from fuel burnt in a closed firebox
 The heat is transferred to the water in a pressurized boiler,The heat is transferred to the water in a pressurized boiler,
ultimately boiling the water and transforming it into saturatedultimately boiling the water and transforming it into saturated
steam. Steam in its saturated state is always produced at thesteam. Steam in its saturated state is always produced at the
temperature of the boiling water, which in turn depends on thetemperature of the boiling water, which in turn depends on the
steam pressure on the water surface within the boiler.steam pressure on the water surface within the boiler.
 The steam is transferred to the motor unit which uses it to pushThe steam is transferred to the motor unit which uses it to push
on a piston sliding inside a cylinder to power machinery.on a piston sliding inside a cylinder to power machinery.
 The used, cooler, lower pressure steam is exhausted toThe used, cooler, lower pressure steam is exhausted to
atmosphere.atmosphere.

9. Double Piston StrokeDouble Piston Stroke

10. Other Types of Steam EnginesOther Types of Steam Engines
 Compounding EnginesCompounding Engines
 Multiple Expansion EnginesMultiple Expansion Engines
 Uniflow EnginesUniflow Engines
 Turbine EnginesTurbine Engines
 Rotary Steam EnginesRotary Steam Engines
 Jet-type Steam EnginesJet-type Steam Engines
 Rocket-type Steam EnginesRocket-type Steam Engines

11. Turbine EngineTurbine Engine