3. An exhaust pipe of 75 mm outside diameter is cool by surrounding it by an annular space containing water. The exhaust
Posted: Sat May 21, 2022 10:44 am
3. An exhaust pipe of 75 mm outside diameter is cool by surrounding it by an annular space containing water. The exhaust gas enters the exhaust pipe at 350° C and the water enters from the mains at 10°C. The heat transfer coefficients for the gases and water are 0.3 and 1.5 kW m-K. and the pipe thickness may be taken to be negligible. The gases are cool to 100 °C and the mean specific heat capacity at constant pressure is 1.13 kJ kg K. The gas flow rate is 200kg/hr and the water flow rate is 1400 kg h. The specific heat capacity of water is 4.19 kg K. calculate: (i) The required pipe length for parallel-flow: (11) The required pipe length for counter-flow.