Answer:
The value of heat transferred watt per foot length Q = 54.78 Watt per foot length.
Explanation:
Diameter of pipe = 2 in = 0.0508 m
Steam temperature = 300 F = 422.04 K
Duct temperature = 70 F = 294.26 K
Emmisivity of surface 1 = 0.79
Emmisivity of surface 2 = 0.276
Net emmisivity of both surfaces ∈ = 0.25
Stefan volazman constant = 5.67 ×
Heat transfer per foot length is given by
Q = ∈ A (
) ------ (1)
Put all the values in equation (1) , we get
Q = 0.25 × 5.67 × × 3.14 × 0.0508 × 1 × (
)
Q = 54.78 Watt per foot.
This is the value of heat transferred watt per foot length.