Refrigerant134a is throttled from saturated liquid at 32 deg

Refrigerant-134a is throttled from saturated liquid at 32 degree C to a temperature of-20 degree C and a state of 30 degree C and 9 bars to a temperature of-120 degree C. Determine the final pressure in bars, the final specific volume.{1.3299bars, 0.0301m^3/kg}

Solution

From R-134a properties at T1 = 32 deg C and quality = 0 (sat. liq), we get P1 = 815 kPa, v1 = 0.000848 m^3/kg, h1 = 96.5 kJ/kg

During throttling, h2 = h1

h2 = 96.5 kJ/kg

From R-134a properties at T2 = 20 deg C and h2 = 96.5 kJ/kg we get, P2 = 572 kPa, v2 = 0.00413 m^3/kg

From R-134a properties at T3 = 30 deg C and P3 = 9 bars we get, v3 = 0.00842 m^3/kg, h3 = 93.6 kJ/kg

h4 = h3 = 93.6 kJ/kg

From R-134a properties at T4 = -12 deg C and h4 = 93.6 kJ/kg we get, P4 = 185 kPa, v4 = 0.0304 m^3/kg