8-77 Liquid water at 200 kPa and 15°C is heated in a cham-

ber by mixing it with superheated steam at 200 kPa and 200°C.

Liquid water enters the mixing chamber at a rate of 4 kg/s, and

the chamber is estimated to lose heat to the surrounding air at

25°C at a rate of 600 kJ/min. If the mixture leaves the mixing

chamber at 200 kPa and 80°C, determine (a) the mass flow

rate of the superheated steam and (b) the wasted work potential

during this mixing process.

15°C

600 kJ/min/n15°C

4 kg/s

200°C

600 kJ/min

2

Mixing

chamber

200 kPa

FIGURE P8-77

80°C