Here I present my solution for the given problem : State 1: saturated vapour T1=263.15 K= -10°C, P1=219.12 kPa, h1=347.13 kJ/kg, s1=1.559 kJ/kg K State 2: superheated vapour P2=1 MPa, T2= 60°C, h2=381.8 kJ/kg State 3: saturated liquid P3=P2=1 MPa, T3=42°C, h3=240 kJ/kg State 4: liquid vapour mixture P4=P1=219.12 kPa, h4=h3=219.13 kJ/kg State 2s:hypothetical state(if process 1 to 2 would have been isoentropic) P2s=P2=P3=1 MPa, s2s=s1=1.559 kJ/kgK T2s=48°C, h2s= 373.5 kJ/kg Now, ql=h1-h4=107.13 kJ/kg qh=h2-h3=141.8 kJ/kg win=h2-h1=34.67 kJ/kg COP = ql/win = 3.08 n(ise)=(h2s-h1) /(h2-h1) =0.76