Apipe, 4.5 cm in diameter and 1×104 cm in length, transports superheated vapor at a rate of 1.08× 106 grams/h. the pipe, which is located in a power plant at 300 k, has a uniform surface temperature of 370 k. if the temperature drop between the inlet and exit of the pipe is 35 k, determine the heat transfer coefficient as a result of convection between the pipe surface and the surroundings. assume, the specific heat of the vapor is 2190 j/kg. k. (20 points)

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

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

WHERE

from both above equation we have

putting all value to get heat transefer coefficient

h = 23.237 W/m2 K

oil flow is a highly convective flow compared to water flow at normal temperature and pressure.

energy can cross the boundaries of a closed system in the form of heat and mass

explanation: