Question

A steam pipe is covered with 1.50 cm thick insulating material with a thermal conductivity of 0.200 cal/cm·°C·s. How much energy is lost every second when the steam is at 250°C and the surrounding air is at 20.0°C? The pipe has a circumference of 800 cm and a length of 65.0 m. Neglect losses through the ends of the pipe.

Answer 1

The heat loss per second is proportional to the area of the pipe and the temperature gradient, with the thermal conductivity as the constant of proportionality. Writing this in equation form:

Given:

, , , ,  

Area of Pipe = 2*pi*r*L = 800cm * 65.0 m = 800 cm * 65.0 cm *100

Plugging in all the values in the above equation:

If you want, you can convert the above answer into Joules by multiplying with 4.186

So,