Perancangan Alat Penukar Kalor
Temperatur dinding tabung dapat dihitung dengan:
K 9186163
, 11
3 T
126353 ,
102 2
0,0117 0,0127
9125431 ,
00 4
48731551 ,
303 9125431
, 00
4 313,4
126353 ,
102 2
0,0117 0,0127
T h
d d
h T
h T
h d
d T
w w
i o
c c
c h
i o
w
= ⋅
+ ⋅
+ ⋅
⋅ =
⋅ +
⋅ +
⋅ ⋅
=
Dari tabel sifat-sifat air laut dengan C
3 38,9186163
273 -
3 311,918616
T
w
° =
= ,
diperoleh: T
C µ
N.sm
2
30 0,00084948
38,91861633 µ
wc
40 0,00069772
µ
wc
= 0,000714131 N.sm
2
. Dari tabel sifat-sifat air dengan
K 9186163
, 11
3 T
w
= , diperoleh:
T K
µ N.sm
2
310 0,000695
311,9186163 µ
wh
315 0,000631
2 wh
N.sm 4
0,00066660 μ
= Nilai koefisien perpindahan panas konveksi pada sisi tabung sebenarnya adalah:
.K Wm
2707238 ,
410 h
.K Wm
9125431 ,
400 1
0,00071413 0008421
, h
μ μ
h
2 c
2 0,14
c 0,14
wc c
c
= ×
= ×
=
Nilai koefisien perpindahan panas konveksi pada sisi cangkang sebenarnya adalah:
.K Wm
383005 ,
095 2
h .K
Wm 126353
, 2102
4 0,00066660
00065148 ,
h μ
μ h
2 h
2 0,14
0,14 wh
h h
= ×
= ×
=
c. Dinding tabung
Dari tabel sifat-sifat tembaga dengan K
9186163 ,
11 3
T
w
= , diperoleh:
T K
k
tembaga
Wm.K 300
401 311,9186163
w
k 400
393 Wm.K
7 400,046510
k
w
= Sehingga,
.K 4Wm
347,430191 U
383005 ,
095 2
1 0,00635
0,00585 0,00585
0,00635 ln
7 400,046510
0,00585 8
410,270723 1
1 U
2 i
i
= +
+ =
Maka panjang tabung:
m 3
32,3289472 L
K 8
9,91242811 Wm.K
4 347,430191
5 0,98024682
m 0,0117
π W
4011,5328 L
LMTD U
F d
π Q
L LMTD
U F
Q L
d π
LMTD U
F Q
A LMTD
A U
F Q
i i
i i
i i
i i
= ⋅
⋅ ⋅
⋅ =
⋅⋅ ⋅
⋅ ⋅
= ⋅⋅
⋅ =
⋅ ⋅
⋅⋅ ⋅
= ⋅
⋅ ⋅
=
Untuk jumlah tabung 37, maka: L = 32,3289472337 = 0,873755331 m. Hasil L yang baru berbeda dengan L yang dimisalkan, maka perhitungan berlanjut
dengan metode iterasi yang ditunjukkan pada tabel berikut: diperoleh L = 0,977400102 m dan yang diambil adalah L = 0,977 m.
Tabel 3.2. Hasil perhitungan panjang alat penukar kalor. Lsem
Nufsem hfsem
Dh Gt
Rec Nucsem
0.6585 7.607464957 400.9125431 0.016273719 150.0944712 3749.301919 54.12196731
0.873755331 6.923015025 364.8421091 0.016273719 150.0944712 3749.301919 54.12196731 0.94658255
6.740711226 355.2347195 0.016273719 150.0944712 3749.301919 54.12196731 0.96847435
6.6895337 352.5376696 0.016273719 150.0944712 3749.301919 54.12196731
0.974834456 6.674953786 351.7693098 0.016273719 150.0944712 3749.301919 54.12196731 0.97666423
6.670782686 351.5494933 0.016273719 150.0944712 3749.301919 54.12196731 0.977189173 6.669587964 351.4865316 0.016273719 150.0944712 3749.301919 54.12196731
0.977339653 6.669245644 351.4684914 0.016273719 150.0944712 3749.301919 54.12196731 0.977382779 6.669147551 351.4633219 0.016273719 150.0944712 3749.301919 54.12196731
0.977395138 6.669119441 351.4618405 0.016273719 150.0944712 3749.301919 54.12196731
0.97739868 6.669111386
351.461416 0.016273719 150.0944712 3749.301919 54.12196731
0.977399695 6.669109077 351.4612943 0.016273719 150.0944712 3749.301919 54.12196731 0.977399985 6.669108416 351.4612595 0.016273719 150.0944712 3749.301919 54.12196731
0.977400069 6.669108226 351.4612495 0.016273719 150.0944712 3749.301919 54.12196731 0.977400093 6.669108172 351.4612466 0.016273719 150.0944712 3749.301919 54.12196731
0.977400099 6.669108156 351.4612458 0.016273719 150.0944712 3749.301919 54.12196731 0.977400101 6.669108152 351.4612456 0.016273719 150.0944712 3749.301919 54.12196731
0.977400102 6.669108151 351.4612455 0.016273719 150.0944712 3749.301919 54.12196731
lanjutan Tabel 3.2. Hcsem
Tt µtf
µtc hf
hc λtembaga
2102.126353 311.9186163 0.000714131 0.000666604 410.2707238 2095.383005 400.0465107 2102.126353 312.0335247 0.000712387 0.000664904 373.4861438
2096.1325 400.037318
2102.126353 312.0646607 0.000711915 0.000664443 363.6849126 2096.335963 400.0348271 2102.126353 312.0734423 0.000711781 0.000664313 360.9331662 2096.393376 400.0341246
2102.126353 312.0759473 0.000711743 0.000664276 360.1492014 2096.409757 400.0339242 2102.126353 312.0766643 0.000711733 0.000664265 359.9249187 2096.414445 400.0338669
2102.126353 312.0768696 0.000711729 0.000664262 359.8606776 2096.415788 400.0338504 2102.126353 312.0769285 0.000711729 0.000664261 359.8422708 2096.416173 400.0338457
2102.126353 312.0769454 0.000711728 0.000664261 359.8369963 2096.416283 400.0338444 2102.126353 312.0769502 0.000711728 0.000664261 359.8354848 2096.416314 400.033844
2102.126353 312.0769516 0.000711728 0.000664261 359.8350516 2096.416323 400.0338439 2102.126353
312.076952 0.000711728 0.000664261 359.8349275 2096.416326 400.0338438 2102.126353 312.0769521 0.000711728 0.000664261 359.8348919 2096.416327 400.0338438
2102.126353 312.0769521 0.000711728 0.000664261 359.8348817 2096.416327 400.0338438 2102.126353 312.0769521 0.000711728 0.000664261 359.8348788 2096.416327 400.0338438
2102.126353 312.0769521 0.000711728 0.000664261 359.834878 2096.416327 400.0338438 2102.126353 312.0769521 0.000711728 0.000664261 359.8348777 2096.416327 400.0338438
2102.126353 312.0769521 0.000711728 0.000664261 359.8348777 2096.416327 400.0338438