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sat. vapor FIGURE P7–130 Answers: (a) 370.4°C, (b) 0.0517 kW/K 7–131 A hot-water stream at 70°C enters an adiabatic mixing
chamber with a mass flow rate of 3.6 kg/s, where it is mixed
with a stream of cold water at 20°C. If the mixture leaves the
chamber at 42°C, determine (a) the mass flow rate of the cold
water and (b) the rate of entropy generation during this adiabatic mixing process. Assume all the streams are at a pressure
of 200 kPa.
7–132 Liquid water at 200 kPa and 20°C is heated in a chamber by mixing it with superheated steam at 200 kPa and 300°C.
Liquid water enters the mixing chamber at a rate of 2.5 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 60°C, determine (a) the mass flow
rate of the superheated steam and (b) the rate of entropy generation during this mixing process.
Answers: (a) 0.152 kg/s, (b) 0.297 kW/K Review Problems
7–137 Show that the difference between the reversible
steady-flow work and reversible moving boundary work is
equal to the flow energy....
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