1. For load cases 1 and 2, determine the net rate of water evaporation from the cooling water to the air using the equation for air flow rate. Compare this with the rate at which make-up water enters the system.

2. For load cases 1 and 2, determine the rate of work supplied by the pump and compare it to the pump power provided by the vendor, 100W. Discuss any discrepancies.

Procedure:

The air flow rate in the cooling tower is: mao 0.0137 = where ma,o is the mass flow rate of dry air in (kg/s), x is the air pressure in mmHO, and vo is the specific volume of the vapor and air mixture leaving the tower in (m/kg). (1) Manually record system parameters at steady state, initial data point (2) Apply a cooling load. Student may select the magnitude of load: Q = 0.5kW, Q = 1kW. X Vo (3) Once steady state is achieved, students manually record system parameters, final data point. Tower 1 Tower 2 The make-up water mass flow rate is shown in the following table: No heat 3x10-4 kg/s 3.78x10-4 kg/s 0.5 kW 3.2x10-4 kg/s 1 kW 3.69x10-4 kg/s