Study of heat transfer coefficient in helical coil
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A.3 Calculation example
The following calculation example is shown, how heat transfer coefficient was calculated for
steady state heat transfer with the flow rate of 0,008556 kg/s and with the agitator in position
8, or at 1703,41 rpm.
The equations (1) and (2) were used.
From equation (2), the amount of heat exchanged is calculated:
Q=0,008556 · 4180373 · ( 42,66-23,62 )=680,95
This is inserted to equation (1)
681
U=
0,163 ·7,21
The logarithmic mean temperature was calculated by equation:
( Tb-T 2 )-(Tb-T 1)
Tlm=
Tb-t 2 (0)
ln ( )
Tb-T 1
44,12-42,66
44,12-23,66
ln (¿)=7,21
( 44,12-42,66 )-(44,12-23,62)
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