1) Four kilograms of water initially at 200 degree Celsius and 0.5 MPa undergo an isothermal, internally reversible compression process to the saturated liquid state.
Determine the work and heat transfer involved in the process (in kJ). Sketch the process on P?v and T?s coordinates. Associate the work and heat transfer with the areas on these diagrams.
2) Seven kilograms of air is contained in a constant? volume tank with 327 degree in Celsius and 120 kPa. Then it is cooled to ambient temperature (27 Celsius).
Determine the entropy change of the air and universe due to the process and sketch the process on the T?s diagram.
3) Two kilograms of water execute a Carnot power cycle. During the isothermal expansion, the water is heated until it is a saturated vapor from an initial state where the pressure is 40 bar and the quality is 15%. The vapor then expands adiabatically to a pressure of 1.5 bar while doing 491.5 kJ/Kg of work.
(a) Sketch the cycle on P?V coordinates.
(b) Evaluate the heat and work for each process, in kJ.
(c) Evaluate the thermal efficiency.