Exergy Efficiency Calculation Formulas
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Questions and Answers

What type of conditions are fully transient conditions machines or systems more convenient for?

  • Non-adiabatic conditions (correct)
  • Endoreversible conditions
  • Irreversible conditions
  • Steady state conditions
  • In the context of exergy efficiency, what has been proved necessary for C.H.P. configurations?

  • Thermofrigopump efficiency
  • Irreversible efficiency
  • Exergy efficiency (correct)
  • Entropy efficiency
  • What is the key difference between exergy efficiency of a machine and the corresponding system efficiency?

  • Adiabatic vs. non-adiabatic operation
  • Energy consumption
  • Temperature dependency
  • Efficiency loss in heat transfer (correct)
  • Which method has been used for comparison that involves cases of adiabatic and non-adiabatic configurations?

    <p>Entropy flux method</p> Signup and view all the answers

    What has been done to the objective function in terms of classical efficiencies?

    <p>Reevaluation based on energy consumption</p> Signup and view all the answers

    What is a significant contribution proposed by the author in terms of extending the classical efficiencies?

    <p>Introduction of useful effect criteria</p> Signup and view all the answers

    What is the general definition of exergy efficiency?

    <p>The ratio of Useful Exergy U.Ex divided by Exergy Consumed Ex.C</p> Signup and view all the answers

    In which case could the machine exergy efficiency be one?

    <p>Only in the endoreversible case</p> Signup and view all the answers

    Which type of system exergy efficiency occurs in both endo and exo reversible cases?

    <p>Thermo Frigo Pump system efficiency</p> Signup and view all the answers

    What happens to the exergy efficiency when going from machine efficiency to system efficiency?

    <p>Decreases</p> Signup and view all the answers

    In the context provided, what does 'w + w'' represent?

    <p>Heat transfer irreversibilities</p> Signup and view all the answers

    What does 'q F' represent in the equations?

    <p>Heat Transferred to the Fluid</p> Signup and view all the answers

    What does the exergy efficiency of a machine represent?

    <p>Internal irreversibilities of the machine</p> Signup and view all the answers

    Why is optimization theoretically possible in a thermomechanical machine?

    <p>Due to two degrees of freedom</p> Signup and view all the answers

    How can unitary cost Ci be related to the dimensions of a machine?

    <p>Through heat transfer conductances</p> Signup and view all the answers

    What characterizes machine or system performance in the absence of supplementary constraints?

    <p>First law efficiency</p> Signup and view all the answers

    Why must a constraint be added for reverse cycle machines in optimization?

    <p>To bound tC and tF variables</p> Signup and view all the answers

    What does optimization of Eq.(14), (15), or (17) give for reverse cycle machines?

    <p>Same solution due to intercalation</p> Signup and view all the answers

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