Lessons from a Heat Exchanger

The amount of heat exchanged and taken up by the evaporating fluid per unit of time, the heat flow rate Q, is positive and is given by 

At the low temperature its quality has decreased and the available work is now less  

the exchange of heat has taken place with a rate of loss of available work  

The enclosed area represents the amount of lost work in this plot of the Carnot factor against 

With this equation in mind, we can read the last part of Equation 3.8a as 

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