Question

6 Water is heated in a pipe by exchanging heat with a warmer fluid that flows outside the pipe. Inside diameter of the pipe is dn 0.045 m and outside diameter dour0.05 m. Mean velocity of the water in the pipe is um-0.31 m/s and the bulk temperature is 323 K (density 988 kg m-3; viscosity 0.00055 kg m' sı. Pr 3.56, thermal conductivity k 0.64 W m1 Kt). The material of the pipe has thermal conductivity k 0.61 W m-1 K-1. The fluid on the outside has a temperature of 443 K and provides a convective heat transfer coefficient hot400 W m2 K1. Using the Dittus-Boelter correlation, determine the inside convective heat transfer coefficient for water. If the pipe length is L 12 m (inside heat transfer surface areaAs = 1.696 m2 and outside heat transfer surface area Aout 1885 m2). calculate the total heat transfer rate for the pipe. (Dittus-Boelter correlation: Nu 0.023 ReoPro 4). 20 marks]

Answer 1

Guven data →Mean 323k ㄧ-) Ten pnatuuobaut.di aicuiat the Ryold 00005S : 25059 27 lu tir iriz 0023x(2 5059 27 3.54 hin1796 5943 m-k

hih. ov4ς To - Tn hout Aut 443-323 ln (002 120