Module 4: Heat transfer calculations, miscellaneous topics and carbon credit
Lecture 34: Heat flow in furnaces and exchangers
Exercise- 4
Air at is passing in a duct of 0.08m diameter at 300K. The wall temperature of the duct is 900K. If the air is heated to a temperature of 800K, what is the length of the duct?
Solution:
Average properties of air at
Heat balance in the small duct length
Where internal diameter of duct, is heat transfer coefficient specific heat, manflow rate
is passing in a duct of 0.08m diameter at 300K. The wall temperature of the duct is 900K. If the air is heated to a temperature of 800K, what is the length of the duct?
internal diameter of duct, 
is heat transfer coefficient 
specific heat, 
manflow rate 
