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Transcript of Cengel ch06
CHAPTER
6
Entropy
FIGURE 6-1The system considered in the development of the Clausius inequality.
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6-1
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6-2
FIGURE 6-5A cycle composed of a reversible and an irreversible process.
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6-3
FIGURE 6-6The entropy change of an isolated system is the sum of the entropy changes of its components, and is never less than zero.
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6-4
FIGURE 6-10The entropy of a
pure substance is determined from the tables (like other properties).
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6-5
FIGURE 6-11Schematic of the T-s diagram for water.
FIGURE 6-16On a T-S diagram, the area under the process curve represents the heat transfer for internally reversible processes.
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6-6
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6-7
FIGURE 6-19The T-S diagram of a Carnot cycle (Example 6–6).
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6-8
FIGURE 6-36The isentropic relations of ideal gases are valid for the isentropic processes of ideal gases only.
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6-9
FIGURE 6-37The use of Pr data for calculating the final temperature during an isentropic process.
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6-10
FIGURE 6-39The use of vr data for calculating the final temperature during an isentropic process (Example 6–10).
FIGURE 6-43Schematic and T-s diagram for Example 6–12.
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6-11
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6-12
FIGURE 6-45P-v diagrams of isentropic, polytropic, and isothermal compression processes between the same pressure limits.
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FIGURE 6-46P-v and T-s diagrams for a two-stage steady-flow compression process.
6-13
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6-14
FIGURE 6-49The h-s diagram for the actual and isentropic processes of an adiabatic turbine.
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6-15
FIGURE 6-51The h-s diagram of the actual and isentropic processes of an adiabatic compressor.
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6-16
FIGURE 6-53Schematic and T-s diagram for Example 6–15.
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6-17
FIGURE 6-54The h-s diagram of the actual and isentropic processes of an adiabatic nozzle.
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6-18
FIGURE 6-61Mechanisms of entropy transfer for a general system.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.FIGURE 6-70Graphical representation of entropy generation during a heat transfer process through a finite temperature difference.
6-19
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6-20
FIGURE 6-76The electrical energy consumed by a motor is inversely proportional to its efficiency.
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6-21
FIGURE 6-77The efficiency of an electric motor decreases at part load.