Water at 80 o C is pumped through 100 m of stainless steel pipe of inner and outer radii 47 mm and 50 mm, respectively. The heat transfer coeffient due to water is 2000 W/m2K. The outer surface of the...

Water at 80^oC is pumped through 100 m of stainless steel pipe of inner and outer radii 47 mm and 50 mm, respectively. The heat transfer coeffient due to water is 2000 W/m2K. The outer surface of the pipe is insulated with a layer of insulation, k=0.1 W/mK and 50 mm thickness. The outer surface of the pipe losses heat by convection to the air at 20^oC and the heat transfer coefficient is 200 W/m2K. The heat loss from the pipe is calculated as 5.44x103W by retaining the thermal resistance for the insulation and ignoring all the other resistances. When this value
is compared with the value calculated by considering all resistance, the error is found less than 1%. By giving the reasons, please explain why the error is less than 1%