(a) Steam at 20 bar and 375 °C expands reversibly in a perfectly thermally insulated cylinder behind a piston until the pressure is 0.35 bar. Sketch the p-v and T-s diagrams for the process and calculate the work done per kilogram of steam for this process. (b) If the process in 3 (a) takes place in a steam turbine which is also perfectly thermally insulated, calculate the work done per kilogram of steam and the mass flow rate of steam for the turbine to develop a power output of 1600 kW.  (c) How will the results for Part (a) and Part (b) compare with that for actual processes, explain the reason for any difference and the effect on the steam mass flow rate to produce the same power output in Part (b) for the actual process.

Q4. A piston-cylinder device whose piston is resting on top of a set of stops initially contains 0.5 kg of helium gas at 100 kPa and 25°C. The mass of the piston is such that 500 kPa of pressure is required to raise it. How much heat must be transferred to the helium before the piston starts rising? Cp = 3.11 kJ/kg K..**

I am getting lost in this practice problem for thermodynamics - thank you! Air at 100 kPa and 280K is compressed steadily to 600 kPa and 400K in an air compressor. The mass flow rate of air through the compressor is 0.02 kg/s and the compressor a heat loss of 16 kJ/kg from the compressor occurs. Assuming steady state steady flow conditions and ideal gas behavior (with constant specific heats, Cp=1.009 kJ/kgK, R=0.287 kJ/kgK, determine: a) The necessary power in put to the compressor(kW).b) The volumetric flow rate of air at the exit of the compressor (m3/s).

A rigid tank of volume 10 m³ initially contains saturated water vapor at a temperature of 120 °C. Steam at a pressure 1.2 MPa and a temperature of 400 °C enters the tank through a valve in steam line that is connected to the tank until the final pressure in the tank is 800 kPa, at which time the temperature is 200 °C. All kinetic and potential energy effects can be neglected. A schematic of the problem and properties at all state points except state 1 are shown in the figure below. All of the properties at state 2 and the inlet state i are provided on the figure. Initial State in Tank T₁-120 °C, Sat. vapor u₁=? kJ/kg V₁=? m³/kg Pi=1.2 MPa, Ti-400 °C hi-3261.3 kJ/kg V=10 m³ Final State in Tank T: 200 °C, P₂-800 kPa u₂= 2631.1 kJ/kg v₂=0.26088 m³/kg Qout For Question 6: The initial specific internal energy, u1, of the saturated vapor in the tank in kJ/kg is