Power Plant Engineering

GAS TURBINE POWER PLANT 301

Now, ηcompressor =^21

21

(T T )

(T T )

a−

−

= 0.84

0.84 =

2

(529.4 305)

(T 305)

−

−

T 2 = 572.2 K

Again 4

5

T

Ta

= 1.736

T 5 a =

1089

1.736

= 627.3 K

Now, ηturbine =^45

45

(T T )

(T T )a

−

−

= 0.85

T 4 – T 5 = 0.85(1089 – 627.3) = 392.4

T 5 = 1089 – 392.4 = 696.6 K

0.84 =

2

(529.4 305)

(T 305)

−

−

T 2 = 572.2 K

Again^4

5

T

Ta

= 1.736

T 5 a =

1089

1.736

= 627.3 K

Now,

Regenerator efficiency ηrg =^32

52

(T T )

(T T )

−

−

T 3 – T 2 = 0.6 × (696.6 – 572.2) = 74.65

T 3 = 572.2 + 74.65 = 646.85 K

(a) Thermal efficiency

ηt =

Useful workdone

Heat supplied

=

45 21

p4 3

[C (T T ) C (T T )]

C(T T)

pp

c

−− −

−

η



ηt =

(392.4 267.2)

(1089 646.85)

0.90

−

−



= 25.48 %

Fig. 9.32

H

φ

Regenerator

4

5

(^36) 5a
2a^2
Te m p. R e d u c e d
due to Transfer
of Heat in H.E.
Regeneration cycle