Air enters the compressor of a simple gas turbine (fig. 1) at 100 kpa, 300 k, with a volumetric flow rate of 5 m3 /s. the compressor pressure ratio is 12 and turbine inlet temperature and exit pressure is 1700 k and 100 kpa respectively. the compressor and turbine both have isentropic efficiencies of 0.8. determine: (a) thermal efficiency of the cycle (b) back work ratio (c) net power developed in kw. assume t0 = 300 k, p0 = 100 kpa.

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)?