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Unformatted text preview: h-s diagram represent two properties of major interest: enthalpy, which is a primary property in
the first-law analysis of the steady-flow devices, and entropy, which is the
property that accounts for irreversibilities during adiabatic processes. In analyzing the steady flow of steam through an adiabatic turbine, for example, the
vertical distance between the inlet and the exit states ( h) is a measure of the
work output of the turbine, and the horizontal distance ( s) is a measure of
the irreversibilities associated with the process (Fig. 7–18).
The h-s diagram is also called a Mollier diagram after the German scientist R. Mollier (1863–1935). An h-s diagram is given in the appendix for
steam in Fig. A–10. EXAMPLE 7–6 The T-S Diagram of the Carnot Cycle Show the Carnot cycle on a T-S diagram and indicate the areas that represent
the heat supplied QH, heat rejected QL, and the net work output Wnet, out on this
diagram. s2 = s1 h
2 ∆s s FIGURE 7–18
For adiabatic steady-flow
devices, the vertical distance h on an
h-s diagram is a measure of work,
and the horizontal distance s is
a measure of irreversibilities.
T TH 1 Wn...
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This document was uploaded on 11/28/2012.
- Spring '09