re of 15,4 and 0.5 bar. Assuming ide

1. In a regenerative steam cycle employing three closed feed heaters the steam is supplied to the turbine at 42 bar and 500 0C and is exhausted to the condenser at 0.035 bar. The bleed steam for the feed heating is taken at pressure of 15,4 and 0.5 bar. Assuming ideal processes and neglecting pump work. Calculate
(i) The fraction of the boiler steam bled at each stage
(ii) The power output of the plant per unit mass flow rate of boiler steam (iii) The cycle efficiency
2. In a gas turbine generating station the overall compression ratio is 12/1, performed in three stages with pressure ratio of 2.5/1,2.4/1 and 2/1 respectively. The air inlet temperature to the plant is 250C and intercooling between stages reduces the temperature of 400C. The HP turbine drives the HP and intermediate-pressure compressor stages, the LP turbine drives the LP compressor and the generator. The gases leaving the LP turbine are passed through a heat exchanger which heats the air leaving the HP compressor. The temperature at inlet to the P turbine is 6500C, and the reheating between turbine stages raises the temperature to 6500C. The gases leave the heat exchanger at a temperature of 2000C. The isentropic efficiency of each compressor stage is 0.83, and the isentropic efficiencies of the HP and LP are 0.85 and 0.88 respectively. Take mechanical efficiency of each shaft as 98%. The air flow mass is 140kg/s. Neglecting pressure losses and changes in kinetic energy and taking the specific heat of water as 4.19KJ/Kg K. Calculate
(i) The power output in Kilowatt
(ii) The cycle efficiency
(iii) The flow of cooling water required for the intercoolers when the rise of water temperature
must not exceed 30K
(iv) The heat exchanger thermal ratio