Question

Refrigerant-134a enters an adiabatic compressor as saturated vapor at 160 kPa at a rate of 2 m³/min and is compressed to a pressure of 900 kPa. Determine the minimum power that must be supplied to the compressor.

Answer 1

Minimum power of compressor = 9.71 kW

Step-by-step explanation:

The values of entropy, initial specific volume and enthalpy are obtained from the table for R-134a.

Entropy, s = 0.942 kJ/kg/K

Specific volume,
`v_(1)` = 0.12355

Enthalpy,
`h_(1)` = 241.4 kJ/kg

Final enthalpy can be found out from the table using the given pressure and entropy.

`h_(2)` = 277.12 kJ/kg/K

Minimum power =
`(dm)/(dt) (h_(2) - h_(1))`

=
`((dV)/(dt) )/(v_(1) )`(
`h_(2)-h_(1)`)

Minimum power = 9.71 kW