The outlet water (L kg/s) from a power plant condenser needs to cool down from Ta to Tn before it can be recirculated back to condense the steam. The cooling

normally takes place in a counter-current natural draft cooling tower. The cross-sectional area of the tower is 40 m? and the volumetric mass transfer coefficient ka is 0.012 kgmol s'm3. Air at atmospheric pressure (101.3 kPa) enters the bottom of the tower at Ti with a percentage humidity of H2. The flow rate of the air with vapour entering the tower is B times of the required minimum air flow 40 kjkg 1 k -1 specific heat capacity is 4.2 kJkg K. Water vapour pressure (pas in kPa) at saturation condition can be expressed by Antoine Equation (t in "C), Inpws3885.7= 16.39 The parameters for calculationt +230.17are given in below table. 1. Produce a saturation curve

Fig: 1

Fig: 2

Fig: 3