OCH353 - ENERGY TECHNOLOGY NOTES - UNIT II

OCH353 ENERGY TECHNOLOGY UNIT II NOTES
Dr R.VENKATRAMANAN,M.E., Ph.D.,
AP - MECH,
7150 SUGUNA COLLEGE ENGINEERING

1. UNIT II -CONVENTIONAL ENERGY
Conventionalenergyresources,Thermal,hydeland
nuclearreactors,thermal,hydelandnuclearpower
plants,efficiency,meritsanddemeritsoftheabove
powerplants,combustionprocesses,fluidizedbed
combustion.

18. Coal Based Thermal Power Plant

19. Layout of Steam Power Plant

29. Nuclear Reactor

31. FLUIDISED BED COMBUSTION (FBC)
•A fluidised bed may be defined as the bed of solid particles
behaving as a fluid.
•When a gas is passed through a packed bed of finely divided
solid particles, it experiences a pressure drop across the bed.
•At low gas velocities, this pressure drop is small and does not
disturb the particles. But if the gas velocity is increased
further, a stage is reached, when particles are suspended in
the gas stream and the packed bed becomes a ‘fluidised bed’.
•With further increase in gas velocity, the bed becomes
turbulent and rapid mixing of particles occurs.
•In general, the behavior of this mixture of solid particles and
gas is like a fluid. Burning of a fuel in such a state is known as
a fluidised bed combustion.

32. FLUIDISED BED COMBUSTION (FBC)

33. •Onthedistributorplatearefedthefuelandinert
materialdolomiteandfromitsbottomairissupplied.
•Thehighvelocityofairkeepsthesolidfeedmaterial
insuspendingconditionduringburning.
•Thegeneratedheatisrapidlytransferredtothewater
passingthroughthetubesimmersedinthebedand
generatedsteamistakenout.
•Duringtheburningsulphurdioxideformedis
absorbedbythedolomiteandpreventsitsescape
withtheexhaustgases.Themoltenslagistapped
fromthetopsurfaceofthebed.

34. •Theprimaryobjectofusingtheinertmaterialisto
controlthebedtemperature,itaccountsfor90%of
thebedvolume.
•Itisverynecessarythattheselectionofaninert
materialshouldbedonejudiciouslyasitremainswith
thefuelincontinuousmotionandathigh
temperaturetothetuneof800°C.
•Moreover,theinertmaterialshouldnotdisintegrate
coal,theparentmaterialofthebed.
•Thecosteconomicshowsthatasavingofabout10%
inoperatingcostand15%capitalcostcouldbe
achievedforaunitratingof120MWanditmaybe
stillhigherforbiggerunits.

35. Advantage of FBC