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Cooling Tower Specifications
Since this is s cooling tower used in a steam power plant therefore it does not
include radiator and it is called Open System Evaporative Cooling.
Condition:
Design of Unit 1 & 2 (4MW each)
(From H.B. STA. MARIA, THERM!"#AMI$S II B%&
Mass of led Stea! in Condenser"ṁSC
ṁSC =(1−m1−m2 )ṁS
¿ (1−0.0422−0.2659 )(1.8896 kgsec )
ṁSC =1.3074 kg
sec
#eat $e%ected in the Condenser"Q R
Q R=ṁSC (h4−h5 )
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¿1.3074 kg
sec (2304.83−163.4 )
kJ
kg
Q R=2804.9352 kW
ig're refer to # ST M$*" $efrigeration & ir Conditioning oo+
($,M $-D-$*C. T M,$S-" //- ,,. page 102
Fan 'ower is t(picall(
3.75hp
1000 kg
min cooled water
SSUM-:
Temperature differential int 3∧t 2 of 3 ℃ and )**+ outgoing humidit( t 4=27℃ ,
li-e human s-in.
$ooling tower to e used is forced draft with an efficienc( of /*+
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The condition of air entering ist DB=20 ℃∧50 humidity
C,,*3 -*C*-C"ɳ C
ɳ C =t a−t b
t a−t w; @ psychometic chact ! =50 ; t DB=20 ℃thet WD=14 ℃
0here1
t a=tempeatue of point 3
t b=tempeatue of point 4
t w=wet bu"b tempeatue of ai @ point 1
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0.70=t a−27 ℃
t a−14 ℃
t a=57 ℃ ; t a=t 3
indt 2=#
t 3−t 2=3 ℃
57−t 2=3 ℃
t 2=54 ℃
#eat alance in Condenser
Q R=ṁw C pw (t 3−t 4 )
0here1 Q= $eat e%ected∈condense
ṁw=mass of watee&uiement
C pw=4.187 kJ
kg− '
2804.9352 kJ
sec=ṁw4.187
kJ
kg− ' (30 ' )
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ṁw=22.3305 kg
sec
Condition of ir 5 1
2from 's(chometric chart, Fig A3)4, Morse Boo-&
p1=1.033 kg
cm2=101.325 k(a
t DB=20 ℃
t WD=14 ℃
! =50
W 1=0.0076 kgkg
h1=39.5 kJ
kg
) 1=0.842 m
3
kg
Condition of ir 52
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Sincet 2=54 ℃ it cannot e located on ps(chrometric chart, then use the
con5entional e6uation1
(ro! # Sta Maria" $efrigeration and ir Conditioning oo+)
! 2= p s2
pd2
0here1
ps2=∂ (essue e*eted by the +apo
pd2= (essue satuation @54 ℃
! 2= Re"ati+e $umidity
2ro! Stea! Ta6le of .eenan and .e7es)
(d2= ( sat @54 ℃
(d2=15.02k(a
Since )**+ Humidit(, then (s2= (d2=15.02k(a
W 2=0.622 (s2
(t − (s2
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VCW/ ¿ṁW + f 4
+ f 4=+ f 7 27
+ f 4=0.0010035m
3
kg
V$0'¿22.3305
kg
sec (0.0010035 m3
kg )
VCW/¿0.00224 m
3
sec
(ro! T Morse" //- oo+)
Cooling Tower $ange
$ange ¿ t a−t b
¿57−27
$ange ¿30
Cooling Tower pproach
pproach ¿ t b−t w
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¿27−14
pproach ¿13
The differentialt b−t w is also important to cooling tower si8e and cost. The
smaller the difference, the larger the tower.
#eat and Mass alance in the Cooling Tower
Mass alance"m¿−mout
ṁ3+ṁa w1=ṁ4+ṁa w2;ṁ4=ṁw=22.3305 kg
sec
ṁ3−ṁ4=ṁa ( w2−w1 )
ṁ3−22.3305=ṁa (0.1082−0.0076 )
ṁ3−22.3305=0.1006ṁa ,❶
#eat alance"Q¿−Qout
ṁ3h3+ṁa h1=ṁ4 h4+ṁa h2
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(ro! Stea! Ta6le .eenan and .e7es)
h3=hf @57 ℃
h3=238.59kJ
kg
h4=h f @27 ℃
h4=113.25 kJ
kg
ṁ3 (238.59 )+ṁa (39.5 )=22.3305 (113.25 )+ṁa (335.5574 )
238.59ṁ3−2528.9291=ṁa (335.5574−39.5 )
ṁ3−10.5995=1.2409ṁa ,❷
E6uate ❶ ❷;
ṁ3−22.3305
0.1006 =
ṁ3−10.5995
1.2409
ṁ3=23.3654 kg
sec
S'6stit'teṁ3 to ❶;
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23.3654−22.3305=0.1006ṁa
ṁa=10.287 kg
sec
8ol'!e of ir"Va
Va¿ṁa) 1
¿10.287 kg
sec (0.842 m3
kg )
Va¿8.6619
m3
kg
Ma+e9'p water"ṁmw
ṁmw=ṁa (W 2−W 1) ¿10.287 kg
sec (0.1082−0.0076 )
ṁmw=1.0349 kg
sec
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an /ower
(fro! T Morse" //D oo+) page 102
Fan 'ower is t(picall(
3.75hp
1000 kg
min
Mass of 0ater $ooled¿22.3305
kg
sec
-an (owe=22.3305
kg
sec .
60 sec
1min .
3.75hp
1000 kg
min
-an (owe=5.0244hp
Capacit7 of Ma+e9'p Water /'!p"VMWP
VMW/¿ṁ /W ) - 5
) - 5=) - 4=0.0010035m
3
kg
¿1.10349 kgsec (0.0010035
m3
kg )
VMW/¿0.011
m3
sec
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#eat -changer design of Unit 1 & 2 (4MW each)
(ro! .ents Mechanical -ngineer #and6oo+)
og Mean Te!perat're Difference (MTD)
0/1D=2 t a−2 t b
ln(2 t a2 t b )
9i5en1
$ondensing pressure ¿0.007 /(a
w: Temperature saturation ¿55.1℃
Te!perat're of cooling water:
t 1=enteingthe condense=27 ℃
t 2="ea+ingthecondense=54 ℃
MTD ; <
2 t a=t 3−t 1
2 t a=55.1−27
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2 t a=28.1 ℃
2 t b=t 4−t 2
2 t b=55.1−54
2 t b=1.1 ℃
0/1D=28.1−1.1
ln
(
28.1
1.1
) 0/1D=8.6408℃.1.8
0/1D=15.55 ℃
-2 U3 S.* D ., M .U3 /U U3 !ass ng condenser
3ina!it +o na lang 7'ng !ass ng stea! pano +a7a 7'n
Cooling Tower Specifications
Since this is s cooling tower used in a steam power plant therefore it does not include
radiator and it is called Open System Evaporative Cooling.
8/9/2019 Cooling Tower Specifications
15/29
Condition:
Design of Unit 1 & 2
(From H.B. STA. MARIA, THERM!"#AMI$S II B%&
#eat $e%ected in the Condenser"Q R
Q R=ṁS (h4−h5 )
¿257.5018723 kg
sec (3352.662−359.86 )
kJ
kg
Q R=770,652.1184 kW
ig're refer to # ST M$*" $efrigeration & ir Conditioning oo+
8/9/2019 Cooling Tower Specifications
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($,M $-D-$*C. T M,$S-" //- ,,. page 102
Fan 'ower is t(picall(
3.75hp
1000 kg
min cooled water
SSUM-:
Temperature differential int 3∧t 2 of 3 ℃ and )**+ outgoing humidit(
t 4=27 ℃ , li-e
human s-in.
$ooling tower to e used is forced draft with an efficienc( of /*+
The condition of air entering ist DB=20 ℃∧50 humidity
C,,*3 -*C*-C"ɳ C
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ɳ C =t a−t b
t a−t w; @ psychometic chact ! =50 ; t DB=20 ℃thet WD=14 ℃
0here1
t a=tempeatue of point 3 t 3 @0.06 /pa=85.94
t b=tempeatue of point 4
t w=wet bu"b tempeatue of ai @ point 1
0.70=85.94−t 4 ℃
85.94−14 ℃
t 4=35.582 ℃; t a=t 3
indt 2=#
t 3−t 2=3 ℃
85.94−t 2=3 ℃
t 2=82.94 ℃
#eat alance in Condenser
Q R=ṁw C pw (t 3−t 4 )
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0here1 Q= $eat e%ected∈condense
ṁw=mass of watee&uiement
C pw=4.187 kJ
kg− '
770,652.1184 kJ
sec=ṁw 4.187
kJ
kg− ' (50.358 ' )
ṁw=3654.996304 kg
sec
Condition of ir 5 1
2from 's(chometric chart, Fig A3)4, Morse Boo-&
p1=1.033 kg
cm2=101.325 k(a
t DB=20 ℃
t WD=14 ℃
! =50
W 1=0.0076 kg
kg
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h1=39.5 kJ
kg
) 1=0.842
m3
kg
Condition of ir 52
Sincet 2=82.94 ℃ it cannot e located on ps(chrometric chart, then use the
con5entional e6uation1
(ro! # Sta Maria" $efrigeration and ir Conditioning oo+)
! 2= p s2
pd2
0here1
ps2=∂ (essue e*eted by the +apo
pd2= (essue satuation @54 ℃
! 2= Re"ati+e $umidity
2ro! Stea! Ta6le of .eenan and .e7es)
(d2= ( sat @82.94 ℃
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(d2=53.32k(a
Since )**+ Humidit(, then (s2= (d2=53.32k(a
W 2=0.622 (s2
(t − (s2
¿ 0.622(53.32)101.325−53.32
W 2=0.690866kg
kg
h2=C pa t 2+W 2 hg2
0here1
C pa=Specific $eat of dy ai=1.0062 kJ
kg− '
t 2=tempeatue@ point 2=82.94 ℃
hg2=entha"py of satuated steam @ t 2
hg2=2648kJ
kg (¿ steamtab"e )
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h2=1.0062 (82.94 )+0.690866 (2648 )
h2=1912.867396 kJ
kg
Capacit7 of Circ'lating Water /'!p"VCWP
VCW/ ¿ṁW + f 4
+ f 4=+ f 7 35.582 ℃
+ f 4=0.0010062537 m
3
kg
V$0'¿3654.996304
kg
sec (0.0010062537 m3
kg )
VCW/¿3.677854
m3
sec
(ro! T Morse" //- oo+)
Cooling Tower $ange
$ange ¿ t a−t b
¿85.94−35.582
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$ange ¿50.358 ℃
Cooling Tower pproach
pproach ¿ t b−t w
¿35.582−14
pproach ¿21.582 ℃
The differentialt b−t w is also important to cooling tower si8e and cost. The smaller
the difference, the larger the tower.
#eat and Mass alance in the Cooling Tower
Mass alance"m¿−mout
ṁ3+ṁa w1=ṁ4+ṁa w2;ṁ4=ṁw=3654.996304 kg
sec
ṁ3−ṁ4=ṁa ( w2−w1 )
ṁ3−3654.996304=ṁa (0.690866−0.0076 )
ṁ3−3654.996304=0.683266ṁa ,❶
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#eat alance"Q¿−Qout
ṁ3h3+ṁa h1=ṁ4 h4+ṁa h2
(ro! Stea! Ta6le .eenan and .e7es)
h3=hf @85.94 ℃
h3=360kJ
kg
h4=hf @35.582 ℃
h4=149.02276 kJ
kg
ṁ3 (360 )+ṁa (39.5 )=3654.996304 (149.02276 )+ṁa (1912.867396 )
360ṁ3−544677.637=ṁa (1912.867396−39.5 )
ṁ3−1512.993436=5.203798322ṁa ❷
E6uate ❶ ❷;
ṁ3−3654.996304
0.683266 =
ṁ3−1512.993436
5.203798322
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ṁ3=3978.754133 kg
sec
S'6stit'teṁ3 to ❶;
3978.754133−3654.996304=0.683266ṁa
ṁa=473.8386357 kg
sec
8ol'!e of ir"Va
Va¿ṁa ) 1
¿473.8386357 kg
sec (0.842 m3
kg )
Va¿398.9721312
m3
kg
Ma+e9'p water"ṁmw
ṁmw=ṁa (W 2−W 1) ¿473.8386357 kg
sec (0.690866−0.0076 )
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ṁmw=323.7578293 kg
sec
an /ower
(fro! T Morse" //D oo+) page 102
Fan 'ower is t(picall(
3.75hp
1000 kg
min
Mass of 0ater $ooled¿3654.996304
kg
sec
-an (owe=3654.996304 kg
sec .
60 sec
1min .
3.75hp
1000 kg
min
-an (owe=822.3741684hp
Capacit7 of Ma+e9'p Water /'!p"VMWP
VMW/¿ṁ /W ) - 5
) - 5=) - 4=0.0010062537 m
3
kg
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¿323.7578293 kg
sec (0.0010062537 m3
kg )
VMW/ ¿0.3257825136 m
3
sec
#eat -changer design of Unit 1 & 2 (4MW each)
(ro! .ents Mechanical -ngineer #and6oo+)
og Mean Te!perat're Difference (MTD)
0/1D=2 t a−2 t b
ln(2 t a2 t b )
9i5en1
$ondensing pressure ¿0.007 /(a
w: Temperature saturation ¿55.1
Te!perat're of cooling water:
t 1=enteingthe condense=27 ℃
t 2="ea+ingthecondense=54 ℃
MTD ;
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2 t a=t 3−t 1
2 t a=55.1−27
2 t a=28.1 ℃
2 t b=t 4−t 2
2 t b=55.1−54
2 t b=1.1 ℃
0/1D=28.1−1.1
ln( 28.11.1 )
0/1D=8.6408℃.1.8
0/1D=15.55 ℃
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