Development of a Dynamic Model for Start-up of CoalFired Pwer Plants

7/24/2019 Development of a Dynamic Model for Start-up of CoalFired Pwer Plants

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u dudt [1, 1, 2, 6]

= 0.01, = 0.01

Tref

= 0.0004, = 0.01

Tref

= 0.0025, = 0.01

[2, 2, 2, 2, 2, 2, 2, 2]

ne = 16

[2, 2, 2, 2, 2, 2, 6]

ne = 16

[1, 1, 1, 1, 1, 5] ne = 10

[5, 1, 1, 1, 1, 1] ne = 10

Tref


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QIN

QLOSS TH TL TH > TL

1 2

TH QIN

2 3

TL

3 4 TL QLOSS

4 1 TH

W

QIN

= W

QIN=

QIN QLOSSQIN

= 1 QLOSSQIN

= 1 TLTH

.

TL TH


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QIN

QLOSS

1 2

2 3

QIN

3 4

4

5

5 6

6 7 7 8 8 1


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t 12

4

12

< t


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hgas,in qgas,in pgas,in

Qgas

hgas,out qgas,out pgas,out

Qwater

dMm

dt =qm,in qm,out,

dUm

dt =qm,inhm,in qm,outhm,out+ Qflow,m,

pm,in pm,out= fmq2m,in

m,

m {gas, steam} Mm Um

m fm fm

Qflow,m =

dQmdt

p

h

M

U

p

T

h

T

Mm Vm

m

V

m


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dMm

dt =Vm

dm

dt

=Vmm

hmp

dhm

dt

+m

pmh

dpm

dt= qm,in

qm,out,

dUm

dt =

d(Vmmhm pmVm)dt

=Vm

d(mhm)

dt dpm

dt

=Vm

hm

dm

dt + m

dhm

dt dpm

dt

=Vm

hm

m

hm

p

dhm

dt + hm

m

pm

h

dpm

dt + m

dhm

dt dpm

dt

=Vm

hm

m

hm

p

+ m

dhm

dt +

hm

m

pm

h

1

dpm

dt

=qm,inhm,in

qm,outhm,out+ Qflow,m.

Vm

m

hm

p

dhm

dt +

m

pm

h

dpm

dt

= qm,in qm,out,

Vm

hm

m

hm

p

+ m

dhm

dt +

hm

m

pm

h

1

dpm

dt

= qm,inhm,inqm,outhm,out + Qflow,m,

cp,wall Mwall

Mwallcp,walld(Twall)

dt =

mgas,steam

Qflow,m,

Qm

Qflow,m= wall,mAwall,m(Tm Twall),

wall,m

Awall,m

m

T

m


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m

T

= m+ T.

T

T =TLTET

1 (Tm Ti).

ET LT

Ti Tm

T

m

m= (m0+ fub)pdm

sb,

dm sb

p

m0 b

fu

fu= 1.5

dmsb

1 + 12

2pET

(dmsb

)3U

100.

T, U , b, m0

T = 2.0 U = 105, b = 2.9 m0 = 3.2

N


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= max min

2 ,

max min

25

550 C

350 C

N T= 100 C

T= 550 C

F(x(t), x(t), u(t), t) = 0, t [t0, tf]


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x(t) = (z(t), y(t))T

z

y

F(z(t), z(t), y(t), u(t), t) = 0, t [t0, tf].

n

minz(t),y(t),u(t),tf,p

(z(tf), y(tf), tf, p)

s.t dz(t)

dt = F(z(t), y(t), u(t), t , p)

0 = G(z(t), y(t), u(t), t , p)

z(0) = z0

0 = Hs(z(ts), y(ts), u(ts), ts, p) s [1,...,ns]

zL z(t) zUyL y(t) yUuL u(t) uUpL p pU

t

L

f tf tU

f

F

G

Hs ts,

z

z0

z,

y

u

p

tf

(t0 < t1 < . . . < tne < tf)

ncp


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ne [ti, ti+1] q1, q2 q3

minxRn

f(x)

s.t c(x) = 0

xL x xU.

x= (dz

dti,q, zi, yi,q, ui,q, t , p)

T

q= 1, . . . , ncp i= 1, . . . , ne

f(x) : Rn R c(x) : Rn Rm

m < n

x

xU Rn xL Rn

xU xL

minxRn

f(x)

s.t c(x) = 0

x(i) 0 i I.

I 1,...,n


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minxRn

(x) :=f(x) n

i=1

ln(x(i))

s.t c(x) = 0.

(x)

x

x(i) >0 iI 0 x x


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u0 = u1 u3 = u4 = u5 = u6 = u7 = u8 u2 u9

5 104

108


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m

flow

h

outflow

p


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use

mdot

in

mdot

in

m

flow

mdot

in

m flow m flow0

G

(port.m

flow)

G ( 0.01)

p

h

outflow

R

C+ O2 > CO2 C O2

CO2


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K

Kexp(T d s)

K

1+Tp1s

Kexp(Tds)1+Tp1s


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water in water out gas in gas out

p

h

T

wall

V

M

c

p

wall

A

wall

alpha

wall

water

Water

poly


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V alve linear

T

Q

flow

m

flow

in

T

in

p

in

p

out

Kt

regRoot(x)

sqrt(x)

regRoot(x) sqrt(x)

x

x= 0


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dudt


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C

C


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TSH4 Tref dudt

dudt

= 0

=

tft0

(TSH4 Tref)2 +

du

dt

2dt,

0 0

min,header header max,header, min,separator separator max,separator .

header separator

=

tft0

dt,

tf

ne ncp

dudt

ne = 10

ne

Tref

105

=


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ne = 10 ncp = 3 max iter = 300 tol= 5e 4

TSH4 Tref

102 101

102 4 102

102 102

1.6 103

10

2

2.5 103 102

4 104 102

104 102

Tref

T =

Tref

Tref


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= 0.01, = 0.01

Tref

= 0.0004, = 0.01

Tref


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= 0.0025, = 0.01

= 102

= 4102 ncp = 3 max iter = 100

tol = 5e

4

[1, 1, 2, 6]

[2, 2, 2, 2, 2, 2, 2, 2]

ne = 16

[2, 2, 2, 2, 2, 2, 6]

[2, 2, 2, 2, 2, 2, 2, 2]

[1, 1, 1, 1, 1, 5]

ne = 10

[5, 1, 1, 1, 1, 1]

ne = 10


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ne

[1, 1, 1, 1, 1]

[2, 2, 2, 2, 2]

[1, 1, 1, 1, 1, 5]

[5, 1, 1, 1, 1, 1]

[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]

[2, 2, 2, 2, 2, 2]

[1, 1, 2, 2, 6]

[2, 2, 2, 2, 6]

[2, 2, 2, 2, 2, 2, 2]

[1, 1, 2, 2, 2, 6]

[2, 2, 2, 2, 2, 2, 2, 2]

[2, 2, 2, 2, 2, 6]

[1, 2, 2, 2, 9]

[1, 1, 2, 2, 3, 3, 4]

[2, 2, 2, 2, 2, 2, 2, 2, 2]

[2, 4, 4, 4]

[2, 2, 2, 2, 2, 2, 2, 2] ne= 16


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[2, 2, 2, 2, 2, 2, 6] ne = 16

[1, 1, 1, 1, 1, 5]

ne = 10


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tft0

dt

ne ne = 18

106


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Date post:	20-Feb-2018
Category:	Documents
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Development of a Dynamic Model for Start-up of CoalFired Pwer Plants

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