# Heat exchanger - efficiency of the cycle

#### EastWindBreaks

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution
Since we want the fluid to be in liquid state before entering a boiler, and super-heated water can only reach 374°C before entering super-critical state, suppose after the expansion, the temperature at point 3 is still higher than 374°C, does that mean the condenser must still reject enough heat to ensure the working fluid is in liquid form, since Q_out is large, the efficiency of the cycle wont be as good?

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#### Chestermiller

Mentor
Let's see what your concept of the process looks like if the temperature at point 3 is above the critical temperature. Please show us the TS diagram, also showing, for reference, the vapor-liquid equilibrium region.

Is this really a homework problem?

#### EastWindBreaks

Let's see what your concept of the process looks like if the temperature at point 3 is above the critical temperature. Please show us the TS diagram, also showing, for reference, the vapor-liquid equilibrium region.

Is this really a homework problem?
its not a homework problem, I was just curious while reading about the textbook chapter on power cycles, since it is desirable to have high temperature input, I was thinking maybe that temperature can be so high that the temperature of the fluid coming out of the turbine might able to reach above 374 Celsius ?

#### Chestermiller

Mentor
its not a homework problem, I was just curious while reading about the textbook chapter on power cycles, since it is desirable to have high temperature input, I was thinking maybe that temperature can be so high that the temperature of the fluid coming out of the turbine might able to reach above 374 Celsius ?
OK. So let's see your TS diagram of the cycle. I'm particularly interested in the part of the path through the condenser (or cold sink).

"Heat exchanger - efficiency of the cycle"

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