Assume heat transfer coefficient to be constant and neglect conduction thermal resistance of copper.

Question

Air with an average velocity of 10 m/s at 300 K enters a copper tube of 11.2 mm diameter and 2.5 m length. The tube wall is maintained at 373 K by condensing steam at atmospheric pressure. Using LMTD method, determine the temperature of air at outlet of tube. Average properties of air are

      k = 0.02624 W/m-k,  c_p = 1.005 kJ/kg-k

      r = 1.174 kg /m³, n = 1.568 ´ 10^–5 m²/s

      Pr = 0.7

 

 

 

 

 

Nu = 0.023 Re0.8 Pr0.4 :   

     Where, d and L are diameter and length of tube respectively.

      Assume heat transfer coefficient to be constant and neglect conduction thermal resistance of copper.