A liquid-vapor mixture of 5kg of water with a quality of 0.75 and a pressure of 5bar is expanded in an isobaric process until no liquid is left in the mixture. Then, the system is expanded in a process where the pressure changes linearly with respect to the volume (P=AV+B) until the pressure and temperature are 1.5bar and 120?C respectively. You are asked to:
(a) Sketch the processes in a P-v diagram with respect to the saturation lines.
(b) Determine the volumes of the three states in m3.
(c) Determine the total work in kJ.
(d) Determine the total heat transfer in kJ.
Problem #2:
A confined quantity of air undergoes two thermodynamic processes departing from an initial equilibrium state where the temperature is 20°C, the absolute pressure is 1bar, and the volume is 0.2m3. First, the volume of the system is doubled through an isobaric process. Then, the volume is reduced back to the initial value through a process where the relation P?V1.4 is maintained constant. You may assume average values for the specific heat capacities (cpand cv) to:
(a) Sketch the processes in a P-V diagram.
(b) Determine the temperature of the three states in K.
(c) Compute the total work in kJ.
(d) Compute the total heat transfer in kJ.
Document Preview: Problem #1:
A liquid-vapor mixture of 5kg of water with a quality of 0.75 and a pressure of 5bar is expanded in an isobaric process until no liquid is left in the mixture. Then, the system is expanded in a process where the pressure changes linearly with respect to the volume (P=AV+B) until the pressure and temperature are 1.5bar and 120?C respectively. You are asked to:
(a) Sketch the processes in a P-v diagram with respect to the saturation lines.
(b) Determine the volumes of the three states in m3.
(c) Determine the total work in kJ.
(d) Determine the total heat transfer in kJ.
Problem #2:
A confined quantity of air undergoes two thermodynamic processes departing from an initial equilibrium state where the temperature is 20°C, the absolute pressure is 1bar, and the volume is 0.2m3. First, the volume of the system is doubled through an isobaric process. Then, the volume is reduced back to the initial value through a process where the relation P?V1.4 is maintained constant. You may assume average values for the specific heat capacities (cp and cv) to:
(a) Sketch the processes in a P-V diagram.
(b) Determine the temperature of the three states in K.
(c) Compute the total work in kJ.
(d) Compute the total heat transfer in kJ.