a) Explanation Write the energy balance for the steady-flow system. E ˙ in − E ˙ out = Δ E ˙ system (I) Here, rate of the rate of net energy transfer in to the control volume is E ˙ in , rate of net energy transfer exit from the control volume is E ˙ out , and rate of change in internal energy within the system is Δ E ˙ system . At steady state, rate of change in internal energy of system is 0. Substitute 0 for Δ E ˙ system in Equation (I) and rewrite the energy balance for the system as, E ˙ in − E ˙ out = 0 E ˙ in = E ˙ out Q ˙ in + m ˙ h 1 = m ˙ h 2 Q ˙ in = m ˙ ( h 2 − h 1 ) = m ˙ c p ( T 2 − T 1 ) (II) Here, rate of heat transfer is Q in , mass flow rate of water is m ˙ , initial temperature is T 1 , final temperature is T 2 , initial enthalpy is h 1 , final enthalpy is h 2 , and specific heat of the water is c p . Calculate the rate of heat transfer ( Q ˙ in ) to the cold water in the heat exchanger using equation (II) b) To determine The exergy destroyed during the process

8th Edition

ISBN: 9780073398174

Author: Yunus A. Cengel Dr., Michael A. Boles

Publisher: McGraw-Hill Education

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Chapter 8.8, Problem 80P

To determine

The rate of heat transfer (Q˙in) to the cold water in the heat exchanger

To determine

The exergy destroyed during the process

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Chapter 8.8, Problem 79P

Chapter 8.8, Problem 81P

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The rate of heat transfer ( Q ˙ in ) to the cold water in the heat exchanger