A binary system power plant uses mercury for the high-temperature cycle and water for the low-temperature cycle, as shown in Fig. 11.39. The temperatures and pressures are shown in the corresponding T–s diagram. The maximum temperature in the steam cycle is where the steam leaves the superheater at point 4 where it is 500°C. Determine the ratio of the mass flow rate of mercury to the mass flow rate of water in the heat exchanger that condenses mercury and boils the water and the thermal efficiency of this ideal cycle.
The following saturation properties for mercury are known
P, MPa Tg, °C hf, kJ/kg hg, kJ/kg sf kJ/kgK sg, kJ/kgK
0.04 309 42.21 335.64 0.1034 0.6073
1.60 562 75.37 364.04 0.1498 0.4954