Refrigerant-134a at 1600 kPa and 80°C is expanded adiabatically in a closed system to 100 kPa with an isentropic expansion efficiency of 85 percent. Determine the second-law efficiency of this expansion. Take T0 = 25°C and P0 = 100 kPa.

Devices can be combined to perform a variety of tasks. An adiabatic compressor, with air as the working fluid, is to be powered by an adiabatic steam turbine, which is also driving a generator. Steam enters the turbine at 12.5 MPa and 500 ∘C at a steady rate of 27.30 kg/s and exits at 10 kPa and a quality of 0.8710. Air enters the compressor at 98 kPa and 295.0 K K at a steady rate of 12.600 kg/s and exits at 1 MPa and 635.0 K. For air, MW=29.0 g/mol, Cp=3.5R. Note: The IUPAC sign convention for work is used. Work into the system has a positive value. What is the magnitude of the power delivered to the generator by the turbine? The answer needs to be in MW.