TOBB ETÜ MAK 201 Termodinamik 2014-2015 Güz Dönemi Ödev 4 1) Consider a 210-MW steam power plant that operates on a simple ideal Rankine cycle. Steam enters the turbine at 10 MPa and 500°C and is cooled in the condenser at a pressure of 10 kPa. Show the cycle on a T-s diagram with respect to saturation lines, and determine: (a) the quality of the steam at the turbine exit (b) the thermal efficiency of the cycle (c) the mass flow rate of the steam. 2) Steam enters an adiabatic turbine at 8 MPa and 500°C with a mass flow rate of 3 kg/s and leaves at 30 kPa. The isentropic efficiency of the turbine is 0.90. Neglecting the kinetic energy change of the steam, determine: (a) the temperature at the turbine exit (b) the power output of the turbine (c) show the cycle on a T-s diagram 3) An insulated piston–cylinder device contains 5 L of saturated liquid water at a constant pressure of 150 kPa. An electric resistance heater inside the cylinder is now turned on and 2200 kJ of energy is transferred to the steam. Determine the entropy change of the water during this process. 4) Refrigerant-134a enters the condenser of a residential heat pump at 800 kPa and 55°C at a rate of 0.018 kg/s and leaves at 750 kPa subcooled by 3°C. The refrigerant enters the compressor at 200 kPa superheated by 4°C. Determine: (a) the isentropic efficiency of the compressor (b) the rate of heat supplied to the heated room (c) the COP of the heat pump. (d) the COP and the rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kPa.