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FUNDAMENTALS OF ENERGY BALANCES
480 K p = 10 83
H′ = 6500
2
p = 1
460 K
H = 6200
2
Enthalpy Actual path
Isentropic
path 290 K
= 4500
H 1
Entropy
Figure 3.5. Mollier diagram, methane
90
Axial - flow
80
Efficiency, Ep, % 70 Centrifugal
60
1.0 10 100
3
Volumetric flow rate (suction conditions), m /s
Figure 3.6. Approximate polytropic efficiencies centrifugal and axial-flow compressors
For an isentropic efficiency of 0.85:
1700
Actual work done on gas D D 2000 cal/mol
0.85
So, actual final enthalpy
0
H D H 1 C 2000 D 6500 cal/mol
2
