Liquid water enters a cooling tower operating at a steady state 40ºc with a mass flow rate of 105 kg/h. cooled water at 25ºc exits the cooling tower at the same mass flow rate. makeup water is supplied at 23ºc. atmospheric air enters the tower at 30ºc, 1 bar, 35% relative humidity. a saturated moist air stream exits at 34 ºc, 1 bar. determine a. the mass flow rates of the dry air and makeup water, each in kg/h. b. teh rate of exergy destruction within the cooling tower, in kw, for t0 = 23ºc

An external consultant recommends that a plant installs a bank of capacitors for power factor correction. this will reduce the peak electrical demand charges by an average of 93 kw every month. the plant current pays $13 per kw in peak demand charges. the capacitor bank will include 223 kw of fixed capacitors, and 183 of variable capacitors. the fixed capacitors cost $59 per kw, and the variable capacitors will cost $65 per kw. the consultant charges 21% of the equipment costs to install the capacitors. because this project will reduce the demand for the electric utility, they are prepared to provide a one-time rebate of $42 per kw of reduced demand. what is the simple payback period for this project (in years)?