Enrico L. Lasa Solved Problems 1. A gas turbine turbine’s ’s combust combustion ion chamber chamber is supplied supplied with with liquid liquid fuel. fuel. The fuel is 1!"1#$ Solve for the balanced combustion equation given the products of combustion are carbon dio%ide and water$ and nitrogen gas. The reactants are the fuel and air given #1 percent of air is o%&gen and '( percent is nitrogen. Solution)
*1!"1# + *,# + *-# *,# + *"#, + *-# 11!"1# + *,# + *-# *,# + *"#, + *-# 11!"1# + *,# + *-# 1!,# + /"#, + *-# 11!"1# + 10,# + 2.(-# 1!,# + /"#, + (2.(-# #. A gas turbine turbine combusti combustion on chamber chamber is supplied supplied with with liquid liquid fuel fuel at 0#3 4 and air at 3! 4. The fuel appro%imates appro%imates to 1!"1#$ and 5ve times the quantit& of air require required d for stoichiomet stoichiometric ric combustio combustion n is supplied. supplied. alculate alculate the fuel6air ratio. omposition of air b& volume) !.'( - #$ !.#1 ! # 7iven molecular weights) arbon 8 1# 9g ,%&gen 8 1/ 9g -itrogen 8 1 9g "&drogen 8 1 9g Solution) The combustion equation) 1!"1# + /3,# + #.3-# 1!,# + /"#, + 3#,# + #.3- # 10#9g
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:uel6air ratio 8 ;eight of fuel6 ;eight of air
0. :rom the previou previous s problem$ problem$ solve solve for the change change in enthalp& enthalp& <="> of water water in vapor.
7iven) :or water at #(2 4$ h fg8 ## 9?69g ="#(24 8 @ #3!! 9?69g 1!"1# Solution) Since the "#, will be in vapor phase$ we require$ =" vap given b&) ="vap 8 <="#(24 >
. ecane is used as a fuel for a gas turbine. etermine the balanced combustion equation if the supplied air is / times its stoichiometric requirement. Assume that air onl& contains #1 percent of o%&gen and '( percent nitrogen. Solution) Stoichiometric balanced combustion equation)
*1!"## + *,# + *-# *,# + *"#, + *-# 11!"## + *,# + *-# *,# + *"#, + *-# 11!"## + *,# + *-# 1!,# + 11"#, + *-# 11!"## + 13.3,# + *-# 1!,# + 11"#, + *-# 11!"## + 13.3,# + 32.0-# 1!,# + 11"#, + 32.0-# Balanced combustion equation with / times suppl& of air)
11!"## + (0,# + 0(.2-# 1!,# + 11"#, + ''.3,# + 0(.2-#
3.
:rom the previous problem$ solve for the air6fuel ratio 7iven molecular weights) arbon 8 1# 9g$ ,%&gen 8 1/ 9g$ h&drogen 8 1 9g$ -itrogen 8 1 9g Solution)
11!"## + (0,# + 0(.2-# 1!,# + 11"#, + ''.3,# + 0(.2-# 1#9g #2!
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Air6fuel ratio 8 weight of air6weight of fuel 8 #('/9g + ('(.9g 61#9g Air6fuel ratio 8 2(.(0
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