Repeat Prob 19135 for a pipe made of copper (k 386 W mK) instead of cast iron Hot water at 90 deg C enters a 15 m section of a cast iron pipe (k 52 W mK) whose inner and outer diameters are 4 and 4 6 cm, respectively, at an average velocity of 1 2 m s The outer surface of the pipe, whose emissivity...

Hot water enters a copper pipe whose outer surface is exposed to cold air with a specified heat tran ...

Repeat Prob. 19135 for a pipe made of copper (k = 386 W/mK) instead of cast iron.

Question:

Repeat Prob. 19€“135 for a pipe made of copper (k = 386 W/mˆ™K) instead of cast iron.

Hot water at 90°C enters a 15-m section of a cast iron pipe (k = 52 W/mˆ™K) whose inner and outer diameters are 4 and 4.6 cm, respectively, at an average velocity of 1.2 m/s. The outer surface of the pipe, whose emissivity is 0.7, is exposed to the cold air at 10°C in a basement, with a convection heat transfer coefficient of l2 W/m²ˆ™K. Taking the walls of the basement to be at 10°C also, determine

(a) The rate of heat loss from the water

(b) The temperature at which the water leaves the basement.

Tamblent E = 0.7 = 10°C Hot water 90°C 1.2 m/s -15 m