1. Three alternative steam cycles illustrated in Fig. 0.1 are proposed for a nuclear power station capable of producing either saturated steam or superheated steam at a tempera- ture of 293 C. The condensing steam temperature is 33C. 293c 33 3 3 293C Cycle #1 33 3 Entropy, s 293C p=5 MPa TA Temperature, T 33 3 3 Cycle #1 5 Entropy, s Cycle #1 Entropy, s Figure 0.1: Alternative ideal Rankine cycles (a) Assuming ideal machinery, calculate the cycle thermal efficiency and steam rate (kg) steam/kWe-hr) for each cycle using the properties below: T=293C: Peat = 7.766 MPa; h = 1,305.34 kJ/kg; h = 2,761.4 kJ/kg; 8 3.1874 kJ/(kg-K); 8, 5.7592 kJ/(kg-K) T =33C: = Psat =0.005034 MPa; hf 138.33 kJ/kg; hg = 2,423.4kJ/kg; 8 0.4781 kJ/(kg-K); 8 = 7.9146 kJ/(kg-K); y = 1.0053x10-3 m/kg p =5 MPa: 8fg Trat = 263.99 C; hj = 1,154.23 kJ/kg; h = 2,794.3kJ/kg p=5MPa and T = 293 C (Superheated): h=2,901.76 kJ/kg; s = 6.16834 kJ/(kg-K) 1 (b) Compare the cycle thermal efficiencies calculated with the Carnot efficiency. (c) For each cycle, compare the amount of heat added per unit mass of working fluid in legs 4-1 for all cycles, and legs 3-4 for Cycles #1 and #3 and leg 3-4 for Cycle #2. (d) Briefly compare advantages and disadvantages of each of these cycles. Which one would you use? Note: This problem is modified from Prob. 6.2 in the text.