A vapor-compression refrigeration system for a household refrigerator has a
refrigerating capacity of \(0.3 \mathrm{~kW}\). Refrigerant enters the
evaporator at \(-23^{\circ} \mathrm{C}\) and exits at \(-18^{\circ} \mathrm{C}\).
The isentropic compressor efficiency is \(80 \%\). The refrigerant condenses at
\(35^{\circ} \mathrm{C}\) and exits the condenser subcooled at \(32^{\circ}
\mathrm{C}\). There are no significant pressure drops in the flows through the
evaporator and condenser. Determine the evaporator and condenser pressures,
each in \(\mathrm{kPa}\), the mass flow rate of refrigerant, in \(\mathrm{kg} /
\mathrm{s}\), the compressor power input, in \(\mathrm{kW}\), and the coefficient
of performance for (a) Refrigerant \(134 a\) and (b) propane as the working
fluid.