Question 1 A cooling water stream leaves the condenser in the formalin 37/3 process at a temperature of 45o C and a flowrate of 12 kg/s. It is sent to a cooling tower to be cooled down to 16o C for recycling back. The worm cooling water is sprayed down from the top of cooling tower. Ambient air is blowed into the cooling tower from the bottom and going up to directly contact with the warm cooling water. The cooling tower is operated adiabatically. It is allocated in Birmingham in the UK.

Calculate:

1. The typical minimum air flowrate required to achieve the cooling if the water vapour reached the saturation in air when the air leaves the cooling tower in January or February.

2. The air flowrate required to achieve the cooling if the air has a relative humidity of 80% when it leaves the cooling tower. (4 marks) If the air flow is fixed at a flowrate as calculated from above (2), calculate

3. the temperature of the cooling water that leaves the cooling tower from the bottom at different time in a selected day. Present your calculation results in a diagram.

4. the waterloss amount at different time in the selected day. Present your calculation results in a diagram. (4 marks)

Comments on your calculation results from 3 and 4 above in terms of 1) how to achieve steadystate operation; 2) the values from site measurements. (2 marks)