Q5. Consider the combined gas-steam power cycle. The topping cycle is a gas- turbine cycle which has a pressure ratio of 8. Air enters the compressor at 300 K and the turbine at 1300 K. The isentropic efficiency of the compressor is 80 percent, and that of the gas turbine is 85 percent. The bottoming cycle is a simple ideal Rankine cycle operating between the pressure limits of 70 bar and 0.05 bar. Steam is generated and heated in a heat exchanger by the exhaust gases to a temperature of 500 °C. The exhaust gases leave the heat exchanger at 450 K. Neglect mass of fuel and take cp for combustion gases as 1.11 kJ/kg K and x =1.33. Draw flow diagram, show the cycle on a T-s diagram and determine, 1- The ratio of the mass flow rates of the steam and the combustion gases 2- The thermal efficiency of combined cycle.