A geothermal supply of hot water at 500 kPa, 1500C is fed to an insulted flash evaporator at the rate of 1.5 kg/s. A stream of saturated liquid at 200 kPa is drained from the bottom of the chamber and a stream of saturated vapour at 200 kPa is drawn from the top and fed to a turbine. Find the rate of entropy generation in the flash evaporator. Properties of water are given in the table below:
| |
| |
|
P, kPa
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t, 0C
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h, kJ/kg
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hv, kJ/kg
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s1,kJ/kg
|
sv, kJ/kg-K
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|
200
|
120.20(tsat)
|
504.68
|
2706.63
|
1.5300
|
7.1271
|
|
500
|
151.53(tsat)
|
640.08
|
2746.60
|
1.8603
|
6.8202
|
|
500
|
150.00
|
632.18
|
-
|
1.8417
|
|
|
|