Question

A large steam pipe is covered with a 2.20 cm thick insulating material with a thermal conductivity of 0.27 W/(m°C). How much energy is lost every second when the temperature of the steam inside the pipe is at 240 °C and the temperature outside of the pipe is 27.0 °C? The pipe has a diameter of 2.40 m and a length 'of 300 m. Neglect losses through the ends of the pipe. Tries 0/12 Submit Answer

Answer 1

Thickness t = 2.20 cm = 0.022 m
Temperature inside pipe Th = 240 deg C
Temperature outside pipe Tl =27 deg C
Diameter = 2.4m
Length = 300m

Area of pipe = 2pi*rl
= pi*d*l
= pi*2.4*300
= 2261.95 m^2

Energy lost per sec = KA(Th-Tl)/t

K = 0.27 W/mC

Energy lost per sec = 0.27*2261.95*(213)/0.022

= 5.912*10^6 J/s