Calculo de eficiencia de un horno

7/24/2019 Calculo de eficiencia de un horno

1/22

CALCULO DE LA EFICIENCI

PROBLDATOS PARA EL PROBLEMA

Flue gas exit temperature 348 FCombustion air temperature 68 F

Ambient air temperature 60 F

fuel gas temperature 77 F

Oxigen in the ue gas (r! basis" 3#$ %&

raiation losses $#' %

fuel omposition) mol#* &ol#%

+etano 36#',

-irogeno $$#8

.tano ,3#4/

.tileno 6#$8ropano 8#$

ropileno '#/'

1utano ,#/$

1utileno $#06

entano 0#44

2itrogeno ,#43

CO 0#74

CO$ 0#,7

-$ 0#0048


2/22

TRMICA DE UN HORNO.uaion eneral e la 5ienia

O2.

e e5ienia termia neta) %

-9 lo:er heat &alue) 1tu*lb of fuel

-a alor sensible el aire entrante) 1tu*lb of fuel

-f alor sensible el fuel entrante) 1tu*lb of fuel

;s peria e alor por himenea) 1tu*lb of fuel

;r peeria por raiaion asumia ) 1tu*lb of fuel

EMAEcuaciones a considerar

as e ombustion < Combustible = .l aire e ombusti>n

+oles teorias el aire e ombustion < +oles e Oxigeno x ,00 * $,

+oles atuales e aire < +oles teorias e aire = .l exeso e aire


3/22

BASE ,00 mol * hr e fuel

masa) lb*hr

+etano 36#', ,6 '84#,6 $,'00-irogeno $$#8 $ 4'#60 ',600

.tano ,3#4/ 30 404#70 $04$0

.tileno 6#$8 $8 ,7'#84 $0$/0

ropano 8#$ 44 360#80 ,//30

ropileno '#/' 4$ $4/#/0 ,/6/0

1utano ,#/$ '8 ,,,#36 ,/670

1utileno $#06 '6 ,,'#36 ,/4$0

entano 0#44 7$ 3,#68 ,/'00

2itrogeno ,#43 $8 40#04 0

CO 0#74 $8 $0#7$ 434'CO$ 0#,7 44 7#48 0

-$ 0#0048 34 0#,6 6''0

?O?A 1! "1#$!%

?O?A) 1?@* lb e fuel

Oxigen in the ue gas (r! basis" 3#$ %

Porcen&a'e en e(ceso de O" ,6#4,6 %

Cantia O$ reuerio $87#'3 mol*hr

Cantia e aire reuerio ,36/#$0 mol*hr

3/706#8, lb*hr

Co)*osici+n de,

moles*hr + +asa lb*h +asa por lb e fuel

CO$ ,37#'3 44 60',#3$ $#8$

-$O $,/#/8 ,8 3/'/#73 ,#84

O$ 0#0048 64 0#307$ 0#00

O$ 40#'4 3$ ,$/7#44 0#60

2$ ,083#,0 $8 303$6#7' ,4#,$

?O?A 1#%1!1/

eria e alor por himenea) ;s ,48,#/'$ btu *lb por fuel

Calor perio por raiaion) ;r ',$#0/4btu *lb por fuel

&ol frai )moles*hr

esomoleular)

lb*mol

; e ombustionneto 1?@*lb

Correion el alor sensible por ombustion e aire)


4/22

-a 3'#4/'4 btu*lb e fuel

Calor entrante $0'$8#$'

.5ienia) e /0#$/

-a*lb e fuel


5/22

SOLUCIN

,$''/440 73#0$ 36#', 73#0$$3'$/60 ,,#40 0 $$#8

8$63/74 47#$$ $6#/8 40#47

3'677/3#6 ,8#84 ,$#'6 ,$#'6

7,/0744 4,#00 $4#6 3$#8

4/$0'3, $6#78 ,7#8' ,7#8'

$,/04',#$ ,$#48 7#68 /#6

$$40$/,#$ ,$#36 8#$4 8#$4

6,7760 3#'$ $#$ $#64

0 0#00 0 0

/00$8#4 0#37 0#74 00 0#00 0 0

,068#/6 0#0, 0 0#0048

#02#"!0/ "#/!%$" 10$!0/ "1!%"#%0!$#

eso moleular el aire $/

% e O$ en el aire $,

+asa e aire reueria* lb e fuel ,8#4/

as e ombustion < Combustible = Aire 4,8'4#6,

+asa e gas e ombustion* lb e fuel ,/#4/

as de Co).us&i+n

6$ ,76#08/ /#$/ ,0#/0

,$8 $3'#/'6 ,4#8' 0#00

44 0#006 0#0003$ 0#00038

'/ 3'#8,6 $#74 3#$,

73 ,034#08' 73#,$ 8'#88

1#%1!2"

Cp aire 0#$4

Cp fuel 0#'3

heating &alue1?@*hr

O$ teorioreuerio mol*hr

CO$ formao por laombustion) mol*hr

-$O formao por laombustion) mol*hr

.ntalpia a lasalia (348"

btu*lb

Contenioalorio) btu*lb of

fuel

1ase humea %9*%mol

1ase sea %9*%mol


6/22

)

-f /#0, btu*lb e fuel

btu*lb e fuel

%


7/22

00

0

0

0

0

0

0

0

0

00

0#0048

!#%

lb*lb of fuel

lb*hr

lb*lb of fuel

O$ formao por laombustion) mol*hr


8/22


9/22

TABLA DE REACCIN DE COMBUS

B.ACCO2

$ ,

0#' 03#' $

3 $

' 3

4#' 3

6#' 4

6 4

8 '

nitrogeno 0 0

0#' ,

CO$ 0 0

,#' 0

/#' 6

, 0

moles e O$ poraa mol e

sustania

moles e CO$ poraa mol e

sustania


10/22

IN

$ 0

, 03 0

$ 0

4 0

3 0

' 0

4 0

6 0

0 0

0 0

0 0

, ,

7 0

0 ,

moles e -$O poraa mol e

sustania

moles e O$ poraa mol e

sustania


11/22

% Oxigeno

0#' $

0#/ 4

,#3 6,#' 7

,#7 8

$#, ,0

$#' ,$

$#7 ,3#8

3#, ,6

3#' ,8

3#/ $,

4#, $$

4#' $4#84#7 $6

4#/ $8

'#3 30#8

'#' 3$#$

'#7 34

6#3 3/

6#' 4,

6#/ 44#4 f(x" 0#00$' DE4 =

7#, 46#$ 4#38'/ DE =

7#' '0#8 % Oxigeno7#7 '3

7#/ '' 3#$

RELACION ENTRE EL CONTENIDO DE O3I4ENO EN EL 4AIRE

%Aire enexeso

0#' ,#'

0

,0

$0

30

40

'0

60

f(x" < 0#00$'3$8843xF4 G 0#0,,4030/3/x

BH < 0#///873883,

6O" 7s 6

6 Aire en E(ceso


12/22

G0#0,,4 DE3 = 0#$6$' DE$ =

G0#,/'7

,6#4,'8

S DE COMBUSTION 5 EL E3CESO DE

%Aire enexeso ) F(x"

$#' 3#' 4#' '#' 6#' 7#' 8#'

3 = 0#$6$4',,6'8xF$ = 4#38'/04$4$3x G 0#,/'7047,33

ire en e(ceso

6 O"


13/22

4R8FICA DE ENTALPIAS 9S TEO$

? (F" - (1tu*lb"

$00 $0

$80 36

3$0 4,348 44

400 ''

440 6$

'$0 78

600 /$

640 ,00

7$0 ,,0

800 ,30

880 ,4$

/60 ,60,000 ,68

,080 ,80

,$00 $0$

,$80 $$0

,3$0 $$'

,400 $4' f(x" DE

,480 $60 0#,/03

,600 $84

,660 300

,7$0 3,0 348,800 3$$

CO$

? (F" - (1tu*lb"

$00 3,

$80 48

348 6$

360 6'

400 7$

440 84'$0 ,04

'60 ,,'

600 ,$'

680 ,4'

7$0 ,'8

760 ,7,

840 ,87

/$0 $,0

?emperatura )F

0 $00 400 6000

'0

,00

,'0

$00

$'0

300

3'0

f(x" < 0#,/030/$'

BH < 0#///074304

SO

ENTALP


14/22

/60 $$0

,000 $30

,,$0 $66

,,60 $78 f(x" DE3

,$00 $84 G0#00000000/

,3$0 3$4

,360 338,400 3'0 348

,480 374

,'60 3/4

,640 4,8

,680 434

,760 4'7

,800 46/

-$O

? (F" - (1tu*lb"$00 6$

$40 80

$80 ,00

3$0 ,,8

348 ,$8

360 ,38

400 ,''

440 ,7'

480 ,/$

'$0 $,0'60 $30

600 $'0

640 $68

680 $88

7$0 30'

760 3$'

800 34'

840 36' f(x" DE

880 38/ 0#4/'4

/$0 408/60 430

,000 4', 348

,040 470

,080 4/$

,,$0 ',0

,,60 '34

,$00 ''4

,$40 '78

?emperatura )

F

?emperatura )F

TEMPERATURA: ;F

$00 400 600

0

,00

$00

300

400

'00

600

f(x" < 0#4/'4434,0'x G 44#BH < 0#///,4/,/34

H"

ENTALP


15/22

,$80 600

O$

? (F" - (1tu*lb"

$00 $'

$80 4'

360 6'400 7'

440 88

/60 $,0

,000 $$0

,040 $30

,080 $4$

,,$0 $'0

,,60 $6$

,$00 $70

,$40 $8$,$80 $/$

,3$0 30$

,360 3,0 ,

,400 3$$

,440 338

,480 34'

,'$0 3'8 f(x" DE

,'60 370 0#$'3

,600 380

,640 3/0,680 400 348

,7$0 4,0

,760 4$0

,800 430

2$

? (F" - (1tu*lb"

$00 37

$40 46

$80 '73$0 6'

348 73

360 78

400 8'

440 /8

480 ,06

'$0 ,,/

'60 ,$/

?emperatura )

F

$00 400 600 80

'0

,00

,'0

$00

$'0

300

3'0

400

4'0

'00

f(x" < 0#$'3037/,,7x G $

BH < 0#///0708,$/

O"

ENTALPIA: BTU = ,.

$'0

300

3'0

400

4'0

'00

f(x" < 0#0000,,

BH < 0#///866,

N"


16/22

600 ,3/

640 ,',

680 ,60

7$0 ,7,

760 ,8,

800 ,8/

840 $0$880 $,$

/$0 $$$

/60 $3$

,000 $4$

,040 $'3

,080 $63

,,$0 $7$ f(x" DE$

,,60 $86 0#0000,

,$00 $//

,$40 308,$80 3,/ 348

,3$0 33,

,360 343

,400 3''

,440 364

,480 376

,'$0 388

,'60 400

,600 4,,

,640 4$0,680 430

,7$0 44,

,760 4'4

,800 463

?emperatura )

F

$00 400 60

'0

,00

,'0

$00

:


17/22

PERATURA

G$,#83/

.ntalpia

44#3/

800 ,000 ,$00 ,400 ,600 ,800 $000

x G $,#838'0408$

EMPERATURA: ;F

00 ,000 ,$00 ,400 ,600 ,800

6$8'78$.G00'xF$ = 0#$00$40'/08x G ,$#846,''083,


18/22

DE$ DE

0#0000' 0#$00$ G,$#846

.ntalpia

6$#'

G44#4,4

.ntalpia

,$7#//

00 ,000 ,$00 ,400 ,600 ,800

,38'4,877

TEMPERATURA: ;F


19/22

G$8#7'3

.ntalpia

'/#$/

0 ,000 ,$00 ,400 ,600 ,800 $000

8#7'3,36687$

TEMPERATURA: ;F

88x$ = 0#$4'4/467$/x G ,3#060/,7,,68

46


20/22

DE

0#$44' G,3#06,

.ntalpia

73#$4

0 800 ,000 ,$00 ,400 ,600 ,800

TEMPERATURA: ;F


21/22


22/22

Calculo de eficiencia de un horno

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