Question 4 You are given a task to build a simple steam power plant operating on the ideal Rankine cycle. To reduce the fuel consumption and maximize profit, you are to design the most efficient power plant design. However, the turbine that your company is procuring cannot withstand moisture content higher than 19%. After discussions with a contractor, he gives the specifications of the plant that he is able to build, as shown in Table 1. As an engineer, select the best specification for the power plant. Give your justifications and calculations. Steam at turbine temperature Turbine pressure Pressure at condenser Table 1 Specifications of the steam power plant Design A 350 °C Design A=B Design C 600°C 600°C 3 МРа 3 MPa 15 MPa 10 kPa 10 kPa 10 kPa Question 5 Air enters the compressor of a regenerative gas-turbine engine at 100 kPa and 300 K and is compressed to 800 kPa. The regenerator has an effectiveness of 65 percent, and the air enters the turbine at 1200 K. For a compressor efficiency of 75 percent and a turbine efficiency of 86 percent, determine a) The heat transfer in the regenerator b) The back-work ratio c) The cycle thermal efficiency Question 6 A steam power plant operates on an ideal reheat-regenerative Rankine cycle and has a net power output of 120 MW. Steam enters the high-pressure turbine at 10MPa and 550°C and leaves at 0.8 MPa. Some steam is extracted at this pressure to heat the feedwater in an open feedwater heater. The rest of the steam if reheated to 500°C and is expanded in the low-pressure turbine to the condenser pressure of 10 kPa. a) Show the cycle on a T-s diagram with respect to the saturation lines b) Determine the mass flow rate of steam through the boiler c) Find the thermal efficiency of the cycle