A vapour compression refrigeration system uses R$-12$ and operates between pressure limits of $0\mathrm{.}745$ and $0\mathrm{.}15$ MPa $.$ The vapour entering the compressor has a temperature of $-10$ degree C and the liquid leaving the condenser is at $28$ degree C$.$ A refrigerating load of $2$ kW is required. Determine the COP and the swept volume of the compressor if it has a volumetric efficiency of $76\%$ and runs at $600$ rpm $.$