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aliaze1
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Homework Statement
As shown in the figure, a system undergoing a power cycle develops a net power output of 1MW while receiving energy by heat transfer from steam condensing from saturated vapor to saturated liquid at a pressure of 100 kPa. Energy is discharged from the cycle by heat transfer to a nearby lake at 17 deg. C. These are the only significant heat transfers. Kinetic and potential energy effects can be ignored. For operation at steady state, determine the minimum theoretical mass flow rate, in kg/s, required by any such cycle.
Homework Equations
(the book has letters with dots above them, these are represented by 'd')
dW = dQH-dQC
The Attempt at a Solution
So I just did this problem again, and here is what I get:
I calculate efficiency, which is 1-(Tc/Th), T being in Kelvin. I get 41/186, or ~0.2204
Then I use the formila Q=W/n, n is efficiency, so it is 1000000/(41/186) = ~4536585.4
Then plugging this Q into the mass flow formula, where gz and V^2/2 are zero:
4530585.4-1000000+m(2675-417), 2675 and 417 being enthalpy values at the states given
I get a negative number, but mass flow rate can't really be negative per say, so I end up with m=1566.2468
Am I right?Thanks!
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