Modern Engineering Thermodynamics

13.14 Ericsson Cycle 491
Q H
4
1
3
4
T
T H
p H = c p L = c
p
p H
T L = c T H = c
T L
3
Q
2
L
p L
2
1
s
(a) T–s diagram
V
(b) p–V diagram
Q regen
Isobaric regenerator
Isobaric regenerator
2 Q regen
1
3 2
4 1
3
4
Q L
Q H Q L Q H
W comp.
W out
W comp.
W out
Isothermal
compressor (T L )
(c) Closed loop Ericson cycle
reciprocating equipment
Isothermal power
piston (T L )
Isothermal
compressor (T L )
Isothermal
turbine (T L )
(d) Closed loop Ericson cycle
turbomachinery equipment
FIGURE 13.40
The Ericsson cycle.
To atmosphere
From atmosphere
Isobaric regenerator
Q regen
Q H
W out
p L = constant
T H
T L
T
p H = constant
s
Q L
Compressor stage
intercoolers
Turbine stage
reheaters
FIGURE 13.41
An open loop gas turbine power plant as an approximation to the Ericsson cycle.
and
j _Q L j = _mT L ðs 2 − s 3 Þ
Equation (7.37) of Chapter 7 gives these entropy changes for the cold ASC as
and
s 1 − s 4 = c p ln ðT 1 /T 4 Þ+ R ln ðp 1 /p 4 Þ = R ln ðp 1 /p 4 Þ
s 2 − s 3 = c p ln ðT 2 /T 3 Þ+ R ln ðp 2 /p 3 Þ = R ln ðp 2 /p 3 Þ