Combustion gases passing through a 0.08-m-internal-diametercircular tube are used to vaporize waste water at atmosphericpressure. Hot gases enter the tube at 115 kPa and 250°C at a meanvelocity of 5 m/s and leave at 150°C. The average heat transfercoefficient is 120 W/m2·K and the inner surfacetemperature of the tube is 110°C.
The properties of air at the average temperature of(250+150)/2=200°C are:
cp = 1023 J/kg.°C
R = 0.287 kJ/kg.K
A) Determine the mass flow rate of the exhaust gases inkg/s.
B) The mass flow rate of exhaust gases is 0.019256706 kg/s.Determine the rate of heat transfer.
C) The rate of heat transfer is 1969.961058 W. Determine thesurface area of the underwater duct.
D) The surface area of an underwater duct is 0.205657855m2. Determine the tube length.
E) Find the rate of evaporation of water. [kg/hr]
