Question

A 5 kg aluminum radiator holds 2 kg of liquid R-134a both at –10°C. The setup is brought indoors and heated with 220 kJ from a heat source at 100°C. Find the total entropy generation for the process assuming the R-134a remains a liquid. 

Answer 1

C.V. The aluminum radiator and the R-134a.

Energy Eq.  m₂u₂ – m₁u₁ = ₁Q₂ – 0

Process: No change in volume so no work as used above. 

The energy equation now becomes (summing over the mass)