Combustion gases enter an insulated turbine operating at steady state at 12 bar, 1500 K with a mass flow rate of 1 kg/s and are expanded to 1 bar, 980 K. The combustion gases can be considered to be an ideal gas mixture with a composition on a molar basis of 9.5% CO2 and 19% H2O and the balance being N2. Kinetic and potential energy effects can be considered negligible Determine:
(a) the turbine isentropic efficiency
(b) the turbine power, in kW.
(c) the rate of entropy production, in kW/K.

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)?