ข้อสอบสามัญเครื่องกล Plant 3/2548

8/14/2019 Plant 3/2548

1/13

1

2 (Power Plant / Gas Turbine) 3/2548

6 4

POWER PLANT 1 - 3 2

GAS TURBINE 4 - 6 2

POWER PLANT

1. 27 MWe 60 bar, 450C Turbine 3 bar Feedheater Turbine Condenser 730 mm Isentropic efficiency Turbine 87%

. Turbine kg/kg Turbine Pump

. GeneratorPower transmission Turbine Generator 95% 98%

. Overall efficiency 90% 10% Auxiliary

(25 )

1P = 60 bar

1T = 450C

2P = 3 bar

3P = vac. 730 mm.Hg.

t = 87%

1h = 3,301 kJ/kg

1s = 6.719 kJ/kgK

3 bar, satT = 133.5C

8/14/2019 Plant 3/2548

2/13

2


fh = 561 kJ/kg

fgh = 2,164 kJ/kg

Q 2'12' x5.3211.672kJ/kgK6.719ss +===

0.9485x 2' = kJ/kg2,613.572,1640.9485561h 2' =+=

2,613.573,301

h3,301

hh

hh0.87 2

2'1

21t

=

==Q

kJ/kg2,702.93h 2 = 3 bar, kJ/kg2,725h g =

2 22 x2,1645612,702.93h +== 0.99x 2 =

( ) kJ/kgK6.93985.3210.991.672s2 =+=

3's= 0.04 bar[ vac.,Hgmm.730PP 3'3 == = 760-730 = 30 mm.Hg 1.01325 bar = 760 mm.Hg bar0.04P3 = ] 6.9398 = 0.422 + 8.051 3'x 3'x = 0.8096 kJ/kg2,090.672,4330.8096121h 3' =+=

2,090.672,702.93

h2,702.93

hh

hh0.87 3

3'2

32t

=

==

kJ/kg2,170.26h 3 = 33 x2,4331212,170.26h +== 0.842x 3 =

Feed Heater Heater( ) ( )( )561621 hhm1hhm =

( ) ( )( )511 h561m15612,702.93m =

54 hh =

( )( )121561m1m2,141.93 11 =

8/14/2019 Plant 3/2548

3/13

3


kg/kg0.1704m1 = ( ) ( )( )32121t hhm1hh1W +=

( ) ( )26.170,293.702,28296.093.702,2301,3 +=

kJ/kg1,039.97441.90598.07 =+=

eMW27OutputNet = 98%95%, mg ==

Turbine eMW290.980.95

27=

=

Boiler 3s 1029m1,039.97 =&

100.39kg/s27.886m s ==& /h

Boiler

OverallBoilerQ

OutputNet90%,

==

( )0.9

hhm

MW2710%MW27

71S

ee

=

&

( )7

3

h3,30127.886

0.91024.3

=

Pump Work, 76 hh =

( )5613,30127.886

1021.87

3

Overall

=

28.62%=

2. 15 bar 300C Parsons turbine 20 stages 0.1

bar Turbine Stage efficiency 75% Reheat factor 1.05 10 MW Turbine Stage

Turbine 1 bar Blade 20 Blade speed ratio = 0.7 Diameter

Turbine Blade =10

1

Blade Blades (25 )

8/14/2019 Plant 3/2548

4/13

4


15 bar, 300C Parsons Turbine 20 Stages 0.1 bar

et MW10W1.05,factorReheat75%,Stage == Stage Degree of Reaction = 50%- Stator Rotor

OptimumC

U

1

W Stage 2Um&= Turbine ( )o Stage ( )s

R so = R Reheat factor

1C

UOptimum 1.050.75o = 7875.0=

o'i

oi

hh

hh

=

15 bar, 300C,

kJ/kg3,039h i =

kJ/kgK6.919s i =

0.1 bar,

kJ/kg921h f =

kJ/kg2,392h fg =

kJ/kgK649.0s f =

kJ/kgK5.7s fg =

o'o'i x7.50.649s6.919s +=== 0.836x o' = ( ) kJ/kg2,191.72,3920.836192h o' =+=

o

8/14/2019 Plant 3/2548

5/13

5


2,191.73,039

h3,0390.7875 o

= kJ/kg2,371.76h o =

20 Stages Stage sW= Stage

20

667.24

20

hh oi =

=

kJ/kg33.36=

2U 33.36U2 =

m/s182.65U = eMW10W =

( ) e3

oi kW1010hhm =&

31010m667.24 =&

kg/s14.99m =& Turbine Turbine, P = 1 bar, Blade = 20 2

0.7C

U

1

=

Stage,( )UCosC2UVUW 11ws ==

21 = Degree of Reaction 50% ( )11s C0.720CosC2UW =

( )[ ]111 C0.70.9397C2C0.7 = 32

1 1033.36C0.8256 == m/s201.02C1 =

m/s140.71U =

, 11a SinCC = aC 1C

= 20Sin201.02Ca

m/s68.75=

Axial-flow Turbine

8/14/2019 Plant 3/2548

6/13

6


v

CACAm aa ==&

1 bar, Saturated Steam, /kgm1.694v 3g =

hdA m=

md h

10

dh m=

10

dA

2m=

1.694

68.75

10

d14.99m

2

m ==&

1.1757d 2m =

m1.084dm =

N

60

NdU m=

( )

rpm.2,479.11.084

60140.71N =

=

3. (25 )

3.1 3.2

1.

1,000 W/m2 () 700 W/m2

8/14/2019 Plant 3/2548

7/13

7


2 Solar Thermal powerplant ( ) Solar Photovoltaic Plant (,Solar Cell)

Solar Photovoltaic Plant (Direct Current, DC) (Alternate Current, AC) (Battery)

( 150 1 ) 15 /

2.

(Propeller Wind Turbine) (Multiple Blade) (High Torque)

( 4 /)

5 10

8/14/2019 Plant 3/2548

8/13

8


GAS TURBINE

4. 7:1 1,000 K 85 % 90% 288 K 750 Cp 1.005 kJ/kg K

(25 )

8/14/2019 Plant 3/2548

9/13

9


8/14/2019 Plant 3/2548

10/13

10


5. Gas turbine power plant Compressor 6 :1 Recuperator Turbine 2 Compressor Turbine Recuperator Turbine 800C Compressor 15C Isentropic efficiency Compressor 80% Turbine 85% 98%

(P) Kinetic energy Potential energy Plant Power0.7 kg/s Thermal ratio Effectiveness Heat exchanger 0.65 = 42.6 MJ/kg 97% Specific fuelconsumption kg/kWh = 1.005 1.147 kJ/kgK

( ) = 1.4 1.333 (25 )

80%c =

98%85%, mtt 21 ===

MJ/kg42.6HV =

kJ/kgK1.147CkJ/kgK,1.005C97%, 9a ppb === 1.3331.4, ga ==

( ) 1.66866rT

T 0.28571.4

0.4

1

c

1

2' a

a

====

K480.522881.668T2' ==

12

12'c

TT

TT0.8

==

240.650.8

288480.52TT 12 =

=

8/14/2019 Plant 3/2548

11/13

11


K528.65T2 =

K1,073C800T3 ==

9

9

1

1

t

4'

3 rT

T

= (1)

cmt WW 1 =Q

af mm ( ) ( )12p43pm TTCTTC ag =

K215.1698.0

240.651.1471.005TT 43 ==

K84.578215.161,073T4 ==

4'3

43

tTT

TT0.85

1

==Q

K13.5320.85

215.16TT 4'3 ==

K819.87253.131,073T4' ==

(1)

1.309rr819.87

1,073 0.2498t

1.333

0.333

t 11===

( ) 2.9384r1.3091t

4.003==

2.0422.9384

6r2t

==

( ) 1.19522.042rT

T 0.24981

t

5'

4 9

9

2===

K717.7381.1952

857.84T5' ==

5'4

54t

TT

TT0.85

2

==

( ) K119.087717.738857.840.85TT 54 ==

K738.753119.087857.84T5 ==

( )54pam TTCm/pPower g =

KkgK

kJ

s

kg087.1911.1470.70.98 =

kW703.39=

8/14/2019 Plant 3/2548

12/13

12


528.65738.753

TT

TT

TT0.65 27

25

27

=

==

K567.361TT 27 =

K665.217528.65136.567T7 =+=

C/C, ( )73paf TTCmHVm g =

( ) /skg0.00769665.2171,07342,600

1.1470.7m ff =

=

/skg0.00793

97.0

00769.0m

ff==

/kWhkg0.2953h

s3,600

kW93.703

kg/s0.00793

W

mf

f ==

42,6000.00793

93.703

HVm

W

f

cy

==

27.74%=

6. SPP Combined cycle 3.16 kg/s =156 /GJ Gasturbine = 25.79 MW Steam turbine 11.45 MW 2

20 bar 250C 2.6 kg/s 30 bar 250C 1.8 kg/s 35.5 MJ/kg (25 )

SPP CC

8/14/2019 Plant 3/2548

13/13

13


NG = 156 /GJHV = 35.5 MJ/kg

GT 25.79 MWST 11.45 MW

1. 20 bar 250C 2.6 kg/s 2. 30 bar 250C 1.8 kg/s

STGT21

+++=

+=cc

1 MW7.552,9042.6hm11 ss

===

2 MW5.1442,8581.8hm22 ss

===

MW112.1835.53.16HVm f ===

44.51%112.18

49.934

112.18

11.4525.795.1447.55cc ==

+++=

Documents

ข้อสอบสามัญเครื่องกล Plant 3/2548