Question

Eight (8) kilogram of saturated vapor of refrigerant R-134a is contained in a closed frictionless piston-cylinder device at a pressure of 200 kPa. Heat is then transferred to the refrigerant. At the end of the process, the refrigerant has a temperature of 70 °C. Determine the amount of heat that is transferred during the process. Also, show the process on a T-v diagram with respect to the saturated liquid and vapor lines. (35 points).

Answer 1

Sclution: Given Data: mass of the refrigerant (m) = 8 kg initial state o: P2 = 200 kPa saturated vapour By R-134 a Table: . 1 specificite enthalpy (hi) = hg @ P = 200 kPa [ht = 241.30 m ка Temperature at point I (TI) Tsaturatian @ 2006P4 T = -10.09°c) a specific volume (VI) vagy @ P 1 - 200 kPa 0.0993 m3 к ] final state ② P2 = 200 kPa Vapour super heated Ву superheated vapour R-134 a Table? ha = h @ P2 = 2000 kPa and T2 = 70°c [ha 314.02 kJ/kg] CSScanned with CamScanner

@ P2 = 200 kPa and T2 = 70c 1) [re > = 0.13639 m3/kg] Amount of heat transfer during this process (0): òa m (ha-ha) 8 ( 314.02 241:30) Ang b. Q 581.76 kJ 个 T-re diagram for this Process : T 70°C keme Pressure constant P = 200 kPa 2 -10.09°C N V2 CSScanned with CamScanner