Two kilograms of Refrigerant-134a contained in a piston-cylinder assembly undergoes the refrigeration/heat pump cycle consisting of...

 

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Two kilograms of Refrigerant-134a contained in a piston-cylinder assembly undergoes the refrigeration/heat pump cycle consisting of the following processes: Process 1-2: Polytropic compression (exponent to be determined) from state 1 which is saturated vapor (x1 = 1.0) at T = -20 C to state 2 at p2 =10 bar and at v2 = 0.02171 m/kg. Process 2-3: Constant pressure (p3-P2 =10 bar) cooling from state 2 at p2 =10 bar and at v2 = 0.02171 m/kg to state 3 (to be determined) with q2-3- -158.6 kJ/kg. Process 3-4: Constant volume (v 4= V 3) cooling from state 3 (to be determined) to state 4 at T 4 = -20 C and v 4= V.3 (to be determined). Process 4-1: Constant Temperature (T 4=T=-20 C) evaporation from state 4 at T 4 = -20 C and v 4= V 3 (to be determined) to state state 1 which is saturated vapor (x1 = 1.0) at T1 = -20 C. Complete the following tasks under the assumption of negligible changes in kinetic and potential energy in all processes. 1. Find and tabulate all the relevant properties which are T, p, v, u, h, and x (when applicable) of the four states. 2. Sketch the thermodynamic cycle in both the T-v and p-v diagrams, including the relevant isothermal and isobaric lines inside and outside of the vapor dome. 3. Calculate the work and heat of all four processes. 4. Calculate the heat entering (Qin) and exiting (Qout) the system during the cycle, the cycle net-work (Wcycle), and the refrigeration and heat pump coefficients of performance of the cycle. Two kilograms of Refrigerant-134a contained in a piston-cylinder assembly undergoes the refrigeration/heat pump cycle consisting of the following processes: Process 1-2: Polytropic compression (exponent to be determined) from state 1 which is saturated vapor (x1 = 1.0) at T = -20 C to state 2 at p2 =10 bar and at v2 = 0.02171 m/kg. Process 2-3: Constant pressure (p3-P2 =10 bar) cooling from state 2 at p2 =10 bar and at v2 = 0.02171 m/kg to state 3 (to be determined) with q2-3- -158.6 kJ/kg. Process 3-4: Constant volume (v 4= V 3) cooling from state 3 (to be determined) to state 4 at T 4 = -20 C and v 4= V.3 (to be determined). Process 4-1: Constant Temperature (T 4=T=-20 C) evaporation from state 4 at T 4 = -20 C and v 4= V 3 (to be determined) to state state 1 which is saturated vapor (x1 = 1.0) at T1 = -20 C. Complete the following tasks under the assumption of negligible changes in kinetic and potential energy in all processes. 1. Find and tabulate all the relevant properties which are T, p, v, u, h, and x (when applicable) of the four states. 2. Sketch the thermodynamic cycle in both the T-v and p-v diagrams, including the relevant isothermal and isobaric lines inside and outside of the vapor dome. 3. Calculate the work and heat of all four processes. 4. Calculate the heat entering (Qin) and exiting (Qout) the system during the cycle, the cycle net-work (Wcycle), and the refrigeration and heat pump coefficients of performance of the cycle.