Respuesta :
Answer:
h = 23.237 W/m2 K
Explanation:
given data:
flow rate = 1.08*10^6 gm/h = 0.3 kg/s
D = 4.5 cm = 0.045 m
L = 10^4 cm = 100 m
surface temperature = 370 K
[tex]\Delta T = 35K[/tex]
Surface heat of vapor = 2190 J/kg.k
From energy conservation principle we have
heat transfer btwn surface and air = heat loss due to flow and temp. drop
where
heat transfer btwn surface and air is due to convection
[tex]Q _{convection} = hA_s (T_S - T_∞)[/tex]
WHERE
[tex]T_S = 370 K[/tex]
[tex]T_∞ = 300 K[/tex]
[tex]Heat\ loss = Q_{loss} = \dot m Cp \Delta T[/tex]
[tex]\dot m = 0.3 kg/s[/tex]
from both above equation we have
[tex]Q_{convection} = Q_{loss} [/tex]
[tex]hA_s (T_S - T_∞) = \dot m Cp \Delta T[/tex]
putting all value to get heat transefer coefficient
[tex]h = \frac{\dot m Cp \Delta T}{A_S((T_S - T_∞)}[/tex]
[tex]h = \frac{0.3*2190*35}{14.137*(370-300)}[/tex]
h = 23.237 W/m2 K
