Water at 150 kPa and 12oC is heated in a mixing chamber at a rate of 3

Question:

Water at 150 kPa and 12oC is heated in a mixing chamber at a rate of 3 kg/s where it is mixed with steam entering at 150 kPa 120oC. The mixture leaves the chamber at 150 kPa and 55oC. Heat is lost to the surrounding air at a rate of 3 kW.
Determine the entropy generation rate during mixing.