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B N G P K O N G
3 4 M O D U L T IN G C O N T R O L S
O P E R T I N G P R O C E D U R E S
C O N T E N T S
CONTENTS INS 210392
1
UNIT MASTER
2 AIR
FLOW
3
FLUE GAS 02 AND
CO CONCENTRATION
4
GAS
FUEL
FLOW
5
OIL
FUEL
FLOW
6
GOVERNOR
POSITION
7
FURNACE PRESSURE
ID
FAN
DAMPERS
8 ID FAN SPEED
9
DRUM LEVEL MOTOR BOILER FEED PUMPS
1
DRUM LEVEL TURBINE BOILER FEED PUMPS
11
DEAERATOR
LEVEL
CONDENSATE PUMPS
12
CONDENSER LEVEL
13
SECONDARY SUPERHEATER OUTLET TEMPERATURES
14
TERTIARY [FINAL] SUPERHTR OUTLET
TEMPERATURES
15
REHEAT
STEAM
TEMPERATURE
[GAS RECIRC]
16
REHEAT
STEAM
TEMPERATURE
[SPRAYS]
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B A N G
P A K O N G
3 4
D C I S
O P E R A T I N G
M O D U L A T I N G
P R O C E D U R E
:
U N I T M A S T E R
C O N T R O L S
MASTER.INS
030992
--------------------------------------------------------------------
SYSTEM
BOILER-TURBINE COORDINATION
CON .T VARIABLE
MEGAWATTS, PRESSURE
CONTROL DEVICE
GOVERNOR, FUEL AND AIR SUBLOOPS
SET
VALUE
REQUIRED UNIT OUTPUT AND PRESSURE
GSM
PB
UNIT
MSTR
GROUP
DISPLAY
001
UNIT MASTER
TX DEVN DISPLAY
089
MASTER & AIR XMTRS
A ) P E R M I S S I V E S
(1)
Coordinated
Mode:
Air Flow,
Fue l
Flow, Governor ,
Main
Steam
Temperature ,
Feedwater Flow
and
Condensate Flow cont ro l s se lec ted to AUTO
(2)
Boiler
Follow Mode: Air Flow, Fuel Flow and Governor (opt ional) se lec ted
to
AUTO
(3)
Base
Input Mode:
Air Flow,
Fuel Flow and Governor (opt ional) se lec ted
to
AUTO
(4) Manual Mode: None.
[Air
flow
may
be on AUTO].
B)
(1)
O P E R A T O R A C T I O N
Pre -se lec t
r equ i r ed
sub loops to AUTO
Procedure].
[Refer to r e levan t Operating
(2) Select Group Operation
Display
001 [ UNIT MSTR ]
and
ENABLE a l l
subwindows.
(3) Select
the
requi r ed mode. The subwindow disp lays the se lec ted mode. I f
the required permiss ives a re not complete, PERMISSIVE LOSS will be
indicated. Any
f au l ty t r ansmi t te r a f f ec ting
the
Unit Master
o r Fue l /Air
Deviat ion condi t ion
will force the
Unit Master to
remain
in Manual Mode.
(4) After about 5 seconds the mode se lec t ion subwindow ind ica tes the mode
ac t ive condit ion.
I f
the system remains in t he
mode
se lec ted s t a tu s it
means t h a t one of the sub loops i s not cor rec t ly
in i t i a l i zed
[balanced].
This
can
be
caused
by
excess ive
a i r flow,
signi f icant
change
in
fue l
heat ing value or f au l ty
t r ansmi t te r
ca l ibra t ion.
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5) The Pressure
Set Point
in i t i l i zes
a t
the ex i s t ing pr e s su r e . Th e
pressure may be s e t to the des i r ed value a f t e r auto
opera t ion
achieved
.
Alternat ively
se lec t
s l id ing
pressure
by se lec t ing AUTO on the
pressure s e t poin t subwindow. Sliding pressure i s
avai lable in
Coordinated
Mode
or Boiler
Follow Mode
with Governor AUTO.
6) The
Targe t
Load
Set Poin t
in i t i a l izes
a t
the exis t ing MW for CO
and
BF
Modes and a t
Fuel
Flow
for BI Mode.
Set
the des i r ed MW load
a t the
Target Load Set Poin t
Subwindow.
7)
Set
the
Minimum
and Maximum
Load
a t
the appropr ia te
subwindows.
This
f ci l i ty
i s mainly
to
l imit t he
load
range
under
Automatic Dispatch
System [ADS] control .
The se t t ing
i s
determined by the number of
burner s in service and any other opera t iona l cons t r a in t s .
8) Set
the r equ i r ed
load
change
r a t e
in MW/MIN a t the Rate subwindow.
Then
se lec t
AUTO a t th i s
subwindow
to permit the
load
change to s ta r t .
9) f ADS control of the
Target Load
i s requi red se lec t AUTO on the
Targe t
Load
subwindow.
ADS
control
i s
avai lable in the CO
Mode only.
C)
C O M M E N T S
1) The maximum load is
l imited
by the auxi l ia ry plant
capaci ty.
[PID:
COAW408]
This i s
calcu la ted from
the
number of
Fans
Feedpumps
Condensate Pumps and oiler
Circu la t ing Water
Pumps in
se rv ice
as
follows:
Each
FD
Fan
360
MW
Each ID
Fan
360 MW
Each MDBFP 90 MW
Each TDBFP 360
MW
Each Cond
Pump 350
MW
Two BCWP 360
MW
Three BCWP
600 MW
The lowest value from the
four
auxi l ia ry
groups
is selected ; for
example one TDBFP and one
MDBFP
would
l imit the t a rge t load to 450
MW
.
The maximum
value
of Auxi l iary
Plant Capacity [APC] i s 635 MW
2)
The
Required
Output
[COAY400]
i s
calcu la ted
from
the
Target
Load
Rate
Se t t e r , Minimum
and
Maximum Limits .
and the
Auxil iary
Plant
Capacity.
The
Required Output
[RO]
i s the se t
poin t
for
Governor Fuel
and
Air
control loops.
3)
f
an
auxi l ia ry t r i p causes the
APC
to
drop
below the ex i s t ing RO
a
RUNBACK
is in i t ia ted. This causes
the
RO to
decrease
as a f a s t r a t e
to
the new value determined by
the
APC. The Unit Master is
automat ical ly
t r ansfe r red
to BI
Mode before
the Runback s ta r t s .
4) The major flow loops a re checked for abnormal devia t ion from t ~
required
value.
This appl ies to
Fuel Air
Governor
Feedwater and
Condensate.
f the aux i l i a ry p lan t
is unable
to
fol low
the
load demand
for
any reason
a
flow
devia t ion
occurs . For
example
fuel
valve
a t
maximum
causes
a
fuel flow low
condi t ion.
Any increase
in
RO is
blocked
and
af te r
a shor t
t ime
delay
the
RO is reduced
unt i l the
devia t ion is
within l imits .
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5) Modes:
MANUAL The t a rge t
load
and requi red
output
t r acks fuel
flow.
The
Air Flow and Oxygen controls may be
placed
on
AUTO The
Air
Demand follows Fuel
Flow
when
above the minimum air flow limit Manual
Mode
s
normally
used
a t
uni t
s t a r t
up
unt i l
s t ab le f i r ing
condit ions
a re achieved.
BASE INPUT The boi ler energy
i npu t [fuel
and air] s se t by the
Target Load. The
re su l t ing MW depends
on the fuel
hea t ing value.
Pressure i s control led to a
f ixed
se t point
i f
the Governor s on
AUTO
[Turbine
Follow]. f the governor i s not auto the
pressure
is
propor t ional to f i r ing r a t e and inverse ly propor t ional to governor
posit ion. Changes in governor posi t ion causes
t rans ien t
change to
MW
Base Input
Mode
s used
when stable boi le r
operat ion s
required.
BOILER FOLLOW The boi ler input i s determined
by
the turbine energy
demand. This s calcu la ted
from
Fi rs t
Stage
Pressure Throt t le
Pressure
and Pressure Set
Point.
Pressure cor rec t ion s
made by
adjus t ing t
boi ler inputs [fuel and air] .
The
governor may
be
on automatic c
manual opera t ion . I f the
governor s on
AUTO i t
controls
MW a t t he
Target Load se t t ing [para 2)]
and
sl id ing
pressure
s
permitted. The
Boiler
Follow
Mode
allows r espons ive
control when the
governor
i s
not
avai lab le
for automatic operat ion.
COORDINATED The boi ler inputs
[fuel
and air] and the governor
respond to a common demand s igna l Required Output. Refer to
Paragraph 2). Sliding pressure and
ADS
control s avai lab le in th is
mode.
The governor is adjus ted
to
cont rol MW and the boi le r
inpu t s
are
regula ted to
maintain pressure . The Coordinated Mode s the
normal
method
of
opera t ion .
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B A N G
P A K O N G 3 4 D C I S
O P E R A T I N G
M O D U L A T I N G
P R O C E D U R E
C O N T R O L S
2
C O M B U S T I O N
A I R F L O W
AIRFLOW.INS 030992
--------------------------------------------------------------------
SYSTEM
COMBUSTION AIR
CONT VARIABLE
TOTAL COMBUSTION AIR FLOW
PID
: SGBF409
CONTROL DEVICE
FD FAN BLADE
PITCH
ANGLE
3SGB-CDR-1,2
SET VALUE
CALCULATED
BY BOILER
MASTER
GSM
PB
COMB AIR
GROUP
DISPLAY
002
COMBUSTION
AIR
TX DEVN
DISPLAY
089
MASTER & AIR XMTRS
A ) P E R M I S S I V E S :
(1)
Fan
se l ec t ed fo r au to operat ion
ON
[ running) .
(2)
Pi tch con t r o l
o l pr e s s u r e 28 Bar.
(3}
No Fuel /Air
Transmit te r
devia t ion .
(4) One o r both ID fan damper AUTO.
B) O P E R A T O R A C T I O N :
(1) Selec t group opera t ion
d isp lay
002 [GSM
COMB
AIR ) and ENABLE t he
subwindows
for
FD fans blade
pi tch .
(2) Check t ha t t he
ind ica ted
Air
Demand
[SV]
i s
a reasonable va lue for t he
ex i s t ing
load condi t ion . [e.g.
for 300MW, should be
approximate ly
50%.
The
minimum
i s
33%]
The
PV and SV
i nd ica t ions
on
Fan
lA
subwindow
should be al igned, ind ica t ing t racking ' balance .
(3) Set b ias se t t ing on Fan lA to ze ro
[cen t re-scale) .
(4) Selec t AUTO for
f ans in
se rv ice .
(5) Adjus t b ia s s e t t e r i f required .
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C) C O M M E N T S :
1) The
bas ic
Air
Demand equals
t he
Required
Output [RO]
calcula ted by
the
Boiler Master . When the Boiler Master
i s
n MAN mode the RO equals
Fuel Flow.
(2) The
excess
a i r s
calcula ted
from the .
RO
and the
02 se t
point . The
excess
a i r component
s added
to the bas ic [s tochiometric] a i r demand.
Refer to
02
control notes.
(3) Air flow
control should be
se lec ted
to au to before l ight-of f ;
th i s
ensures tha t the
flow
i s mainta ined above the minimum a i r flow required
for purge. [The minimum a i r flow
i s
se t a t
33 ECR
flow.]
(4)
Boiler Trip
[MFT]
t r i p s
a i r
flow to manual. I t
may
be r e s e t
a f t e r
one
minute.
(5) After
se lec t ing Air Auto
AUTO wil l
be indica ted
on t he subwindow
i t
permiss ives
a re OK The
MAN indica t ion
will remain
on
unt i l
boile
·
master permiss ives
and
in i t i a l iza t ion check i s
complete
[WAITING]. This
takes about 5 seconds. f
MAN remains
on
a i r
flow
may be excess ive
for
f i r ing ra te , or boi le r master permiss ives not
complete
o r ID fan
damper
Not
Auto
.
f a i r flow i s excess ive t he
PV
and
SV
arrows
on
Fan
lA
subwindow
will not al ign and the f lue gas
02
indica t ion will be
higher than the se t poin t
.
Reduce a i r flow unt i l t racking
balance
s
achieved.
(6) Pi tch o l
pressure low
[
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B A N G
P A K O N G
3/4
M O D U L A T I N G
C O N T R O L S
O P E R A T I N G
P R O C E D U R E
3
F L U E G A S O X Y G E N
&
C A R B O N M O N O X I D E
02ANDCO.INS 030992
--------------------------------------------------------------------
SYSTEM
COMBUSTION AIR
CONl' VARIABLE
FLUE GAS 02
&
CO CONCENTRATION
CONTROL DEVICE
EXCESS AIR DEMAND
SET VALUE
CALCULATED BY AIR FLOW CONTROL
GSM
PB
COMB AIR
GROUP
DISPLAY
002
COMBUSTION
AIR
TX DEVN DISPLAY
089
MASTER
& AIR
XMTRS
A)
P E R M I S S I V E S
Flue
Gas
02
(1) No
02
t r ansmi t te r
devia t ion . [Monitor
ON.]
(2)
Air
Flow
Contol
se lec ted
to
AUTO.
(3)
Air
Flow
grea te r
t han minimum f low [33% ECR].
Flue Gas
co
(1) No CO t r ansmi t te r devia t ion .
[Monitor
ON.]
(2) 02 cont ro l
AUTO.
B)
O P E R A T O R A C T I O N
Flue
Gas
02
(1) Check 02 t r ansmi t te r s [4] for reasonable value . [Display 089]. f l l
OK,
se lec t Transmit te r
1
for Eas t
and West s ide s with monitor ON.
(2) Select
group
opera t ion
d i sp lay 002
[Combustion Air] and ENABLE
subwindows
3
and
4.
With
CO cont ro l
in MAN, s e t
output
[MV]
of
CO
subwindow
to
zero. [Centre-scale . ]
(3) Check
02
s e t
value
on
subwindow
3 SV. This i s calcu la ted from
boi le r
load.
I f
a di f fe ren t
value
is requi red
manual ly
ad jus t CO con t ro l
ou tpu t MV [subwindow 4] to ob ta in t he
des i r ed
s e t value
on the
Z
cont ro l subwindow SV. The range of adjus tment is l imited to / 2 02.
(4) Select AUTO
on
02
subwindow.
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Flue Gas CO
1) Check
CO
t ransmit te rs
for
reasonable
value . [Display 089]. f both OK
se lec t t ransmit te r 1 with monitor ON.
2)
Selec t
group
opera t ion display
002
[Combustion
Air}
and enable
subwindow
4.
Adjust
t he
se t value SV to t he r equ i r ed value.
3)
Select
AUTO on CO
subwindow .
C ) C O M M E N T S
1) Manual adjus tment of
excess a i r
s
made
from t he
02
subwindow MV
in
MAN mode.
The
02
MV can only
be ad jus ted
when
combustion a i r control
[FD
fans] s
in
AUTO mode.
2)
When 02 cont ro l
i s
suspended
because
t he i r flow i s
a t m ~ n ~ m u m
both
AUTO
and
MAN indica t ions show
on
the
02
subwindow [WAITING].
3) The
rea l time
t r end
for a i r flow fuel flow 02 and CO
should
be checked
f requent ly for normal
combustion condi t ions.
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B A N G P A K O N G
3 4
D C I S
M O D U L A T I N G C O N T R O L S
O P E R A T I N G P R O C E D U R E
4
G A S
F U E L F L O W
GASFUEL.INS 030992
SYSTEM GAS FUEL
CONT
VARIABLE
GAS
FUEL
FLOW
FGAF408
CONTROL DEVICE CONTROL VALVES
3FGA-ACV-l ,
SET VALUE
CALCULATED BY BOILER MASTER
GSM PB FUEL
GROUP DISPLAY
004 FUEL
TX
DEVN
DISPLAY
090
FUEL
FLOW XMTRS
A )
P E R M I S S I V E S :
(1)
Any burner l eve l se lec ted fo r GAS f i r i ng
(2) Tr ip Valve open; header
p ressu re
>
0.11
Bar.
(3)
No Fue l /A i r
t ransmi t te r
dev ia t ion
4) No Heat Release/Metered
Fue l
Flow deviat ion
(5) Fue l /A i r Rat io normal.
(6) M.F.T. reset
(7) Combust ion
Ai r selected
to
AUTO.
(8) Boi le r Master
Mode
selected [CO, BF
o r BI] .
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B A N G P A K O N G
3 4
D C I S
M O D U L A T I N G
C O N T R O L S
O P E R A T I N G P R O C E D U R E
O I L
F U E L
F L O W
OILFUEL.INS 030992
SYSTEM
OIL FUEL
CONT
VARIABLE OIL FUEL
FLOW
FOBF407
CONTROL DEVICE
CONTROL
VALVES
3FOB-ACV-7,8
SET
VALUE CALCULATED BY BOILER MASTER
GSM PB
FUEL
GROUP
DISPLAY
004
FUEL
TX
DEVN DISPLAY
090 FUEL FLOW XMTRS
A ) P E R M I S S I V E S :
1) Any burner l e ve l selected
f o r
o l f i r i ng
2) Tr ip Valve open; header
p ressu re
> 6.5 Bar.
3)
No
Fue l /A i r
t ransmi t te r
dev ia t ion
4) No Heat Release/Metered Fuel
Flow
dev ia t ion
5) Fuel /A i r Rat io normal.
6) M.F.T. reset
7)
Combust ion Ai r selected to AUTO.
8) Boi le r Master
Mode
selected [CO,
BF o r BI] .
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2
B : : l
O P E R A T O R
A C T I O N
[OIL
O N L Y
FIRING]
(1)
Select
Group Operat ion Display 004 (FUEL) and ENABLE
subwindow
of
the
fuel o l control
valve requi red for auto operat ion . [Only
ONE
valve
of
pa i r
ACV-7/ACV-8
permit ted on
auto a t same
time; each
valve s
>100
capaci ty] .
(2)
Check fuel flow
PV
s
reasonable
value for the exis t ing load condition.
Note
tha t
SV t r acks fuel .
(3) Select
AUTO for
t he
r equ i r ed valve.
(4)
Note AUTO indica t ion
on;
a t th i s
s t age
MANUAL indica t ion also
on.
[WAITING]
If
no
AUTO, check
permiss ives
A)
and t rack ing .
(5)
Select
BOILER MASTER Group Operat ion Display 001.
(6) Select
Governor
mode
[Auto/Manual],
Coordinated Control
mode
[BI,
BF
or
CO]
and Pressure mode [Sl iding/Fixed].
{Refer
to
separa te
procedure f
Boiler Master.}
(7) After
in i t i a l iza t ion and balance
check
[5
seconds] , the
se lec ted boi le r
master
mode
becomes
ac t ive
and t he fuel ,
(as well
as a i r and governor)
go to Auto Mode. The
subwindow MANUAL ind ica t ion s now off.
B2
C O M B I N E D F I R I N G
(1) Refer
to
Fuel Gas Operat ing Procedure for permiss ives for Gas f i r ing.
(2) If
AUTO opera t ion
of gas
fuel required,
se l ec t requi red
gas
valve to
AUTO.
(3) Set
Oil Ratio
Set te r
to
requi red
percentage
o l
flow.
[The Oil
Ratio
Set te r t r acks
the
percentage o l
fuel
i f BOTH fuels a re NOT
auto.]
C) C O M M E N T S :
(1)
Oil fuel
flow
control
funct ions
between burner
header
p res su re
l imits
7.5
to
21.0
Bar.
I f
a
l imit
s
reached,
the fuel
o l
flow
control
t rans fe rs to pressure
control .
An
.
alarm
i s
in i t i a ted to advise Oil
Limited condit ion
exis ts . If
gas
i s
on auto,
the oi l er ro r s
t rans fer red to
the
gas control .
(2)
Each o l fuel control valve i s
>100
capac i ty and
only
one can be on
AUTO
a t one
time. If
opera t ing
condi t ions requ i re the second valve
to
be
opened
i t
must
be under
manual
control .
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BANG PAKONG
3 4
MODULAT ING
CONTROLS
O P ERAT I NG
PROCEDURE
6 GOVERNOR
POSITION
GOVERNOR.INS
030992
--------------------------------------------------------------------
SYST M
TURBINE GOVER'NOR
CONT VARIABLE
GOVERNOR
VALVE
POSITION
CONTROL
DEVICE
DEH GOVERNOR
LOAD
SETTER
SET VALUE
CALCULATED BY UNIT MASTER
GSM PB
UNIT MSTR
GRP OPN DISPLAY 001
UNIT
MASTER
TX
DEVN DISPLAY 089
MASTER
AIR
XMTRS
A)
P E RM IS S IV E S
(1) DEH Auto Permiss ive ON [MHI]
(2) DEH IMP Contro l OFF [MHI]
(3) No
t ransmi t te r
deviat ion:
F i rs t
Stage
Pressure [P1]
Thro t t le Pressure
[Pt]
Megawatt
(4) MW/P1 comparison agree.
{5) Uni t Master Mode Selected : [CO, BF o r BI].
B)
OPERATOR ACT I ON
(1) Select Fuel
and
Ai r AUTO [ r e fe r
re levan t
Operat ing Procedure] .
(2)
Select
Group
Operat ion Disp lay 001 (UNIT
MSTR) and ENABLE Subwindow 7,
Governor
Posi t ion
Demand .
(3)
Check PV and
SV [Governor
Demand] are t rack ing and
a t reasonable
value
fo r ex is t i ng load. [e.g. a t 300MW,
PV
= 50 )
(5) Select Governor AUTO.
-
(6) Note AUTO
i nd i ca t ion ON; a t t h i s
stage MAN i nd ica t ion is
a lso
ON
[WAITING].
If no AUTO,
check
permissives and t rack ing .
-
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-2 -
7) Select requi red Unit Master
Mode.
[Refer
Procedure
1)
{Note: f
Boiler
Follow or Base Input Mode already operat ing , the
Governor may be se lec ted to AUTO a t any time
without re se lec ting the
opera t ing
mode.}
8)
After
in i t i a l iza t ion
and
balance
check,
[5
seconds)
t he se lec ted
Unit
Master mode becomes ac t ive and the governor as
well as
a i r and
fuel)
go
to
Auto Mode. The
Governor
subwindow
MANUAL indica t ion
goes OFF
when
the
DEH accepts
AUTO condit ion from the DCIS. f t he DEH does
not
accept
AUTO
t he
Unit
Master
governor control r e j ec t s
to
MAN. [Refer
to
DEH Operat ing
Ins t ruct ion.
C)
C O M M E N T S
1) In BF
and
CO
Modes,
the governor controls the W
output
to the
value
se t
a t
t he Target
Load
subwindow. In BI Mode, the governor cont ro l s
pressure to the
value
s e t a t the
Pr e s su r e
Set Poin t
subwindow.
2)
Governor
INCREASE i s blocked when
DEH on
Load Limit ON
or
Pressure
is
LOW.
Governor
DECREASE
is
blocked when Pressure
s
HIGH. Refer
also
to
Required
Output
block condit ions, Ins t ruc t ion 1 [Unit Master] Section
C-4.
3)
MANUAL
cont ro l
of governor
va lves i s NOT avai lable from the Unit Master
Governor
subwindow.
MANUAL
CONTROL OF THE GOVERNOR IS ONLY AVAILABLE FROM THE MHI
DEH
GOVERNOR PANEL.
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B A N G P A K O N G 3 4 D C I S M O D U L A T I N G
C O N T R O L S
O P E R A T I N G P R O C E D U R E
7 - F U R N A C E
P R E S S U R E
ID F A N D A M P E R S
IDFDAMP.INS 030992
--------------------------------------------------------------------
SYSTEM
INDUCED DRAFT.
CONT VARIABLE:
FURNACE PRESSURE
PID: SGAP401
CONT DEVICE:
ID FAN
INLET DAMPERS
CDR-127
CDR-128
SET VALUE - )
20
mm
GSM PB
FURN GAS
GROUP
DISPLAY
003
FURNACE
GAS
TX
DEVN DISPLAY 089 MASTER & AIR XMTRS
A ) P E R M I S S I V E S :
(1)
Fan
se lec ted
for
Auto
operat ion
ON
[running]
(2) No Furnace Pressure
Transmitter
Deviat ion
[Monitor ON]
B)
O P E R A T O R
A C T I O N
1) Selec t Group Operat ion Display
003.
[Press GSM FURN GAS )
and
ENABLE
subwindows for
ID Fan
dampers.
(2) Check furnace pressure s e t point. [Normally -20
mm
WG].
3)
Set BIAS
adjustment
on Fan
1B subwindow
a t
zero [cent re -sca le ] .
4)
Select
AUTO
for
ID
Fans
in
serv ice .
Note
tha t
the
Blue
AUTO
ind icat ion
i s ON.
(5) Observe
furnace pressure t rend for
s t ab le
operat ion.
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2
c)
COMMENTS
1)
Either
or both
fans may
be
selected for
automatic
control
.
AUTO mode
should
be
selected immediately af te r
fan
s ta r t .
2) A separa te sub-window [003-1] is provided
for
the se t point .
3) ID Fan speed control
i s
normally in AUTO mode. I f MANUAL adjust speed
to produce
about
60-70 damper opening a t
requi red load.
4)
I f the actual
pressure
i s
more
t han
/
25mm from
the s e t point ,
damper
movement which increases the
error magnitude is
blocked. This
appl ies
in MANUAL
and
AUTO
modes.
5)
The control led var iable i s the median value from th ree t ransmit ters .
6)
Display
a
rea l
time
t rend
of
furnace
pressure
a t
l l
t imes and check
frequently for abnormal pat terns .
[PID: SGAP401]. ·
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B A N G P A K O N G 3 4 D C I S
M O D U L A T I N G
C O N T R O L S
O P E R A T I N G
P R O C E D U R E
8
ID
F A N S P E E D
IDSPEED.INS
030992
SYSTEM INDUCED DRAFT
CONT VARIABLE
ID FAN
SPEED
CCES009,CCES010
CONTROL DEVICE ID FAN HYDRAULIC COUPLING 3CCE-FAN-1A,
lB
SET VALUE
C a l c u l a t e d
f rom FD a v e r a g e b l a d e p i t c h
GSM PB
FURN GAS
GROUP
DISPLAY
003 FURNACE GAS
TX DEVN
DISPLAY N/A
A ) P E R M I S S I V E S :
(1) Fan
se l ec t ed
for Auto
operat ion
i s
ON
[ running] .
(2) No
Furnace
Pressure Transmit te r Deviat ion [Monitor ON].
(3) Hydraul ic coupl ing
se l ec t ed to
REMOTE.
B)
O P E R A T O R A C T I O N
(1) Selec t
Group
Opera t ion
Display 003
[ FURN GAS ] and ENABLE subwindows
for
ID Fan
hydaul ic
coupl ings .
(2) Adjus t
BIAS se t t ing
on Fan lB
subwindow to
zero [cen tre - sca le ] .
(3) Selec t
UTO
for
ID
Fans
in se rv ice .
(4) Adjus t b ia s se t t i ng i required .
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2
C) COMMENTS
(1) Either or both fans may
be
se lec ted for
automatic control . Control
may
be
selected
to
UTO
immediately
af te r
fan
s ta r t .
(2) I f furnace pressure s more than
/-
25
mm
from the
s e t
point any
speed change
command in
the·
direc t ion which increases the er ro r
magnitude s blocked.
This appl ies
n
M NU L and UTO modes.
(3)
The Process Variable s the average speed demand with time constant to
s imulate
actua l
speed response.
·
Transfer
to UTO
s
bumpless
the
speed
will
slowly go to the calculated
se t
point.
(4) The
m n mum speed
under
auto control s
40 . Do not
opera te a t lower
speeds as ins tabi l i ty
[hunting]
may occur.
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B A N G
P A K O N G 3/4 D C I S
O P E R A T I N G
M O D U L A T I N G
P R O C E D U R E
C O N T R O L S
M O T O R
B O I L E R
F E E D P U M P S
MDBFP.INS 030992
--------------------------------------------------------------------
SYSTEM
FEEDWATER [MOTOR DRIVEN PUMPS]
CON
.T VARIABLE
DRUM
LEVEL
CONTROL DEVICE
MDBFP 3A, 3B HYDRAULIC COUPLING SPEED
SET VALUE
0 mm
GSM PB
FEED
WTR
GROUP
DISPLAY
010
FEEDWATER
TX DEVN
DISPLAY
092
CNDS FEEDWATER XMTRS
A)
P E R M I S S I V E S :
(1)
Pump
se lec ted for au to
operat ion ON [Running).
(2) No
t r ansmi t te r
deviat ion:
B)
feedwater flow h i range]
f i r s t
s tage pr e s su r e
drum l eve l [east ,
west]
O P E R A T O R A C T I O N
(1) Select group opera t ion
disp lay
010 [FEED
WTR] and
ENABLE subwindow
of
pumps required
on AUTO.
(2)
Check
drum l eve l s e t point . [Normally 0 mm).
Check
l eve l
ind icat ion
aga ins t
Hydrostep. Check
feedwater
flow PV and SV on
Pump
3A
subwindow
for
t r ack balance and reasonable value
for
ex is t ing load
condi t ion.
(3) Set BIAS se t t ing on
pump
3B
to
zero [cen t re-scale] .
(4) Select AUTO for Motor Pumps in serv ice . [Note: The pump speed demand
will go to the
minimum
value r equ i r ed for
pumping a t
the p reva i l ing
drum pressure .
(5)
Adjust bias
se t t e r
i f
required.
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-2 -
C) C O M M E N T S :
(1) The drum leve l
is normally
the average
of the medians
of the
eas t and
west
sides
The
leve l ind icat ion i s densi ty
compensated
over the range
0 -
220
Bar. A
sepa ra te
subwindow i s
provided
for the drum l eve l se t
point.
(2} The feedwater demand FWAF431 i s t he steam flow
f i rs t
stage pressure}
plus drum leve l correct ion.
When s team
flow i nc reases
or decreases ,
the
feedwater flow
f i r s t goes
n t he oppos i te
direct ion to the steam
flow to
compensate
for
drum
l eve l
swel l / shr ink
effect . The feedwater
demand i s the s e t value (SV}
disp layed on
pump 3A subwindow. The flow
range
i s
0-125 ECR.
(3} The feedwater flow (PV) i s
indicated
on
both
pump subwindows.
The
pump
control le r adjusts pump speed so
t ha t
feedwater flow
always
equals
feedwater demand (SV). The 3B pump subwindow SV i s BIAS, range / 20
speed.
(4) The pump speed range i s 2100-7000
r.p.m.
for 0-100
contro l
outpu t
A minimum pump speed bias s calculated from boiler drum pressure .
This fac tor i s added
to
the
speed demand in
auto mode. When
a
pump i s
se lec ted
to
auto,
the
speed demand
immediately
goes
to the calcu la ted
minimum
value.
At th is
minimum speed
the pump pressure
i s
almost
equal
to the drum pressure and
the
pump can immediately
contr ibute flow.
The
second pump may
be
se lec ted to auto a t any speed; balancing s
automatic and bumpless.
(5) When turbine
dr iven
pumps
a re
a l so
se lec ted to
AUTO, the motor
dr iven
pumps follow the turbine pump
control le r
output . Because of dif fer ing
pump
character is t ics ,
the
percentage
flow
may
not
be
the
same
for
turbine and motor pumps.
(6) f
i t s
necessary
to use
manual control for
drum
level , f i r s t make a
t rend
disp lay
showing drum l eve l (SGFL407}, feedwater flow (FWAF419}
and
steam
flow (TGFP400). When leve l s decreasing, INCREASE the flow; when
leve l
s increasing, DECREASE the
flow.
DO
NOT wait for
leve l
to reach
the
se t point before
reve rs ing the
flow. Try to
est imate the average
flow
for
the
exis t ing load
and work
around
tha t
point .
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B A N G P A K O N G 3/4 D C I S
M O D U L A T I N G
C O N T R O L S
O P E R A T I N G P R O C E D U R E
10
T U R B I N E
B O I L E R
F E E D P U M P S
TDBFP.INS
030992
--------------------------------------------------------------------
SYSTEM
FEEDWATER [TURBINE DRIVEN PUMPS]
CONT VARIABLE
DRUM
LEVEL
CONTROL DEVICE
TDBFP 2A, 2B
DEH GOVERNOR SPEED
SETTING
SET VALUE
0 mm
GSM PB
FEED
WTR
GROUP DISPLAY
010
FEEDWATER
TX DEVN DISPLAY
092
CNDS & FEEDWATER XMTRS
A) P E R M I S S I V E S :
(1)
Pump
se lec ted for au to operat ion
ON
[ running] .
(2) No t r ansmi t te r deviat ion:
Feedwater flow h i range]
Fi r s t
s tage
pressure
Drum l eve l [east /west]
(3)
DEH
in
Auto [Remote] mode
(TGFZ541
ON)
B)
O P E R A T O R
A C T I O N
(1) Select group opera t ion disp lay
010
[FEED
WTR] and
ENABLE
subwindow of
pumps required
on AUTO.
(2)
Check drum
l eve l
s e t
point .
[Normally
0
mm].
Check
l eve l
ind icat ion
aga ins t Hydrostep. Check ·
feedwater
flow PV and SV on Pump 2A
subwindow
for
reasonable value for ex is t ing load condit ion.
(3) Set BIAS
se t t ing on
pump
2B
to zero
[cen t re scale] .
(4) Select
AUTO
for Motor Pumps in serv ice . The pump speed demand
MV)
will
go
to the
minimum
value r equ i r ed for
pumping
a t the p reva i l ing
drum
pressure .
(5) Adjust b ias
se t t e r i f
required.
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- 2 -
C ) C O M M E N T S :
(1) The
drum level
i s
normally t he
average of
the medians of the eas t and
west
sides
The
leve l ind ica t ion
is
densi ty
compensated
over
the
range
0 -
220 Bar.
A sepa ra te
subwindow
i s
provided for the
drum
leve l se t
point .
(2) The feedwater demand FWAF431
is the steam
flow
f i rs t s t age pressure)
plus
drum l eve l
cor rec t ion.
When
steam
flow i nc reases
or decreases ,
the
feedwater flow f i r s t goes in
the oppos i te d i r ec t ion to the steam
flow
to
compensate
for
drum l eve l swel l / shr ink effect .
The
feedwater
demand i s the s e t value (SV)
displayed on pump
2A subwindow. The flow
range
is
0-125%ECR.
(3) The feedwater flow (PV) i s
indica ted on both
2A and 2B subwindows. The
pump
cont ro l l e r ad jus t s
pump
speed
so tha t
feedwater flow
always
equals
feedwater
demand
(SV).
The
2B
pump
subwindow
SV
i s
BIAS, rang
/
20% speed.
(4) The
pump
speed range
is
2700-5600
r.p.m. for 0-100 control output
(MV).
A
minimum pump
speed
bias
i s
calcula ted
from
boi le r
drum
pressure .
This fac tor i s added to the
speed demand in
au to mode.
When a
pump i s
se lec ted
to auto, t he speed
demand goes to
t he
calcula ted minimum
value.
At th i s minimum speed the
pump pressure
i s almost equal to the drum
pressure
and
the
pump
can immediately
cont r ibu te flow.
The second
pump may be
se lec ted
to
auto a t any speed;
balancing
i s
automatic
and
bumpless.
(5) A
tu rb ine dr iven
pump
cannot
be
control led
from
the
DCIS
[auto
or
manual]
unless
DEH
AUTO [Remote] s igna l
i s
received. When
a
pump is
NOT DEH
AUTO ,
the
subwindow
outpu t [MV] t racks t he
DEH
in te rna l speed
reference
[FWAS031,
030].
(6)
Motor dr iven pumps may
be opera ted
on AUTO in para l le l
with
the
tu rb ine pumps. Because of dif fer ing charac ter i s t ics , the
percentage
flow may
not
be the
same
for
turbine and motor pumps.
(7)
f
i t
is
necessa ry to
use
manual control for
drum
level , f i r s t make
a
t r end
display
showing drum level
(SGFL407), feedwater flow (FWAF419)
and
steam
flow (TGFP400). When l eve l
i s
decreasing, INCREASE t he flow; when
leve l
is increas ing,
DECREASE
the
flow. DO
NOT
wait for l eve l
to reach
the se t point before reversing the flow. Try to es t imate
t he
average
flow for
the
ex i s t ing load
and
work
around tha t
point .
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B A N G
P A K O N G 3 4
D C I S
O P E R A T I N G
M O D U L A T I N G
P R O C E D U R E
11
D E A E R A T O R
L E V E L
C O N T R O L S
DEALVL.INS
030992
--------------------------------------------------------------------
SYSTEM
CONDENSATE
CONT VARIABLE
DEAERATOR LEVEL
CONTROL DEVICE
CONDENSATE PUMP
SPEED
3FWC-P-1A,
lB, lC
SET VALUE
LEVEL:
70% 2132 mm]; PRESSURE: 5
b a r
GSM PB
DEA & CNDS
GROUP DISPLAY
014
DEA & CONDENSATE
TX DEVN DISPLAY
092
CNDS & FEEDWATER XMTRS
A ) P E R M I S S I V E S :
(1) Selec ted Condensate
Pump
ON
(2) No
Condensate Flow t ransmit ter devia t ion
(3) No Deaera tor
Level t ransmit ter devia t ion
B) O P E R A T O R
A C T I O N
(1)
Select group
operat ion d isp lay 014
and
ENABLE subwindow of
pumps
r equ i red
on
AUTO.
(2) Check s e t poin t for
deaera tor
leve l and condensa te
pressure .
(3) Set bias se t t ings to zero [cen t re-scale] .
( 4) Select AUTO for pumps in serv ice .
5)
Adjust bias s e t t e r s i required .
(
C ) C O M M E N T S :
1}
The minimum
speed
demand for au to operat ion i s 30% speed.
(2)
Under
normal condi t ions, t he
condensa te
pr e s su r e will be
gr e a t e r
t han
the
minimum
s e t point . I f the
pressure fa l l s below
the
minimum
pressure , the
l eve l
cont ro l
s suspended
and the pump
speed s
adjus ted to mainta in
the r equ i r ed pressure .
(3) I f deaera to r
l eve l i s
grea te r
t han
90% [2525 mm],
the deae ra tor high
l eve l con t ro l le r opens overf low valves
ACV-170, 173
and dumps t he
excess condensa te to
the
condenser . The high l eve l
control
s always
in
auto mode. [GSM: DEA MISC ]
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B N G
P K O N G
3/4 D C I S
O P E R T I N G
M O D U L T IN G
P R O C E D U R E
12 C O N D E N S E R L E V E L
C O N T R O L S
CONDLVL.INS
030992
--------------------------------------------------------------------
SYSTEM
CON.T
VARIABLE
CONTROL DEVICE
SET VALUE
MAKEUP
SET VALUE DUMP
GSM
PB
GRP OPN
DISPLAY
TX DEVN DISPLAY
CONDENSATE
CONDENSER
LEVEL
NORMAL MAKE UP-VALVE
ACV-54
EMERGENCY
MAKE-UP
VALVE ACV-57
CONDENSATE DUMP VALVE
ACV-63
70
90%
DEA CNDS
014
DEA
CONDENSATE
098
HEATER
LEVEL
XMTRS
A)
P E R M I S S I V E S
(1) No
condenser l eve l
t ransmi t ter
devia t ion [Moni tor
ON].
B)
O P E R T O R
C T I O N
(1)
Check
l eve l
t ransmi t ters fo r reasonable value
[Tx
Disp lay
098].
f both
OK
select
t ransmi t te r 1
and
moni tor ON.
(2)
Select Group
Operat ion
Display
014 [DEA CONDENSATE] and ENABL
Subwindows
6,7,8. [ACV-54, 57, 63]
(3)
Adjust
set po in ts [SV] to requi red value.
(4)
Select
AUTO f o r the three valves
[ACV-54,
57, 63]
C) C O M M E N T S
(1) Under
normal
operat ing
condi t ions,
condensate
losses
wi l l be made
up by
valve
ACV-54. Valves ACV-57 and ACV-63 wi l l be
shut. Emergency
Makeup Valve ACV-57 wi l l open i high water l oss causes ACV-54
to
be
100
open.
(2)
Changes
in
operat ing
condi t ions
can
cause a
t rans ient
i nc rease o f
condenser
l eve l
The
make-up
valves
ACV-57
and
ACV-54
close
as
the
l eve l
approaches the
se t
value. Above the
se t
value, both
make-uo
valves
are closed. f the l eve l is grea te r the dump se t value,
the
dur
valve ACV-63 opens. The opening s propor t i ona l
to
the l v ~ devia t ion
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B A N G P A K O N G 3/4
M O D U L A T I N G
C O N T R O L S
O P E R A T I N G P R O C E D U R E
13
S E C O N D A R Y
S U P E R H E A T E R O U T L E T
T E M P E R A T U R E
SECSHO.INS
030992
--------------------------------------------------------------------
SYSTEM
MAIN STEAM
CONT
VARIABLE
SECONDARY SUPERHTR OUTLET TEMPERATURES
2A,2B
CONTROL
DEVICE
1ST STAGE DESH
lA lB lC lD SPRAY CONTROL
VALVES
lC: ACV-357 & ACV-362
lD: ACV-368 & ACV-373
1A: ACV-227 & ACV-232
lB: ACV-319 & ACV-325
SET
VALUE
CALCULATED FROM
BOILER LOAD.
[Refer B(3)]
GSM PB
SSHA SPRAY [TO
STEAM LINE 2A FROM DESH 1C, 1D]
SSHB SPRAY [TO STEAM
LINE
2B
FROM
DESH 1A, 1B]
GROUP DISPLAY
TX DEVN
DISPLAY
006
SEC
SH TO 2A LINE
007 SEC SH TO 2B LINE
094
STEAM TEMP
XMTRS 1
A) P E R M I S S I V E S
(1) No
thermocouple deviat ion [Monitors
ON]
(2) No
f i r s t stage
pressure deviat ion
[Monitor
ON]
(3)
Modulate permit from
BVI
logic ON
(4) No
CLOSE VALVE
command
from
BVI logic
B)
O P E R A T O R
A C T I O N
(1)
Check thermocouples [Display 094] for reasonable
values
and
pair
agreement.
(2)
Select group operation display 006 [GSM: SSHA
SPRAY].
ENABLE
subwindows for
se t
value
and for valves
required
for operation.
(3)
Select AUTO
on
se t point subwindow
[1].
I f manual
se t
point required,
select MAN
and
adjust
se t
value
to the required
temperature.
(4) Select
AUTO
for
DESH
1C,1D
required spraywater valves.
(5)
Select
group
operation display
007
[GSM:
SSHB
SPRAY].
subwindows
for valves required for
operation.
(6)
Select
AUTO
for DESH
1A,1B
required spraywater valves.
ENABLE
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-2 -
C )
C O M M E N T S
(1)
There
are
th ree
sec t ions
of
main steam superhea t ing; PRIMARY
uncontrolled),
SECONDARY
control led by
the
f i r s t stage desuperheaters
lC,lD,1A,lB)
and
TERTIARY [FINAL]
control led by the second s t age
desuperheaters A and
2B).
(2) . The
steam
l ines from each s ide of t he secondary superhea te r ou t l e t
header CROSS OVER before
going
to the second stage desuperheaters A
and
2B. [DESH 1C,1D > 2A; 1A,1B > 2B]
(3) A sepa ra te con t ro l system i s provided for each side
of
the secondary
superheater .
The same
se t
value s used
for
each system.
(4)
Each desuperheater
has
two
100 spray
valves. Only ONE valve can be
AUTO
a t
the
same
time.
(5) The
se t poin t
subwindow
appear s on
group
opera t ion displays
006 ana
007. Either
may be used.
(6) A sepa ra te ins t ruc t ion
s
provided
for t he
t e r t i a ry
superhea te r
out le t
temperature control .
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B A N G P A K O N G
3/4 M O D U L A T I N G C O N T R O L S
O P E R A T I N G P R O C E D U R E
14 T E R T I A R Y
F I N A L )
S U P E R H E A T E R
O U T L E T
T E M P E R A T U R E
TERSHO.INS 030992
--------------------------------------------------------------------
SYSTEM
CONT VARIABLE
CONTROL DEVICE
SET
VALUE
GSM PB
GROUP DISPLAY
TX DEVN DISPLAY
MAIN
STEAM
TERTIARY SUPERHTR OUTLET
TEMPS
(WEST,EAST)
2ND STAGE
DESH
2A,2B SPRAY CONTROL VALVES
2A: ACV-215 ACV-220
2B :
ACV-330 ACV-336
CALCULATED
FROM
BOILER
LOAD
[R e fe r
B ( 3 ) ]
TSH
SPRAY
008 TERTIARY
SH
094,095
STEAM
TEMP XMTRS
1, 2
A) P E R M I S S I V E S
1) No
thermocouple
dev ia t ion
[Moni tors
ON].
(2} No f i r s t
stage
pressure dev ia t i on
[Moni tor
ON].
(3} Modulate
permi t
f rom
BVI logic ON
(4}
No CLOSE
VALVE
command
f rom
BVI logic
B)
O P E R A T O R
A C T I O N
(1) Check thermocouples [D isp lay
094,095]
fo r reasonable values and
pa i r
agreement
.
(2)
Select group
opera t i on d isp lay 008 [GSM: TSH SPRAY ]. ENABLE
subwindows
f o r
se t va lue and
fo r va lves
requ i red
f o r
operat ion.
(3)
Select AUTO on
se t
po in t
subwindow
[1]. If manual set po in t requ i red ,
se lec t MAN
and ad jus t
set value to the requ i red temperature [Usual ly
540 deg].
(4)
Select
AUTO fo r DESH 2A,2B requ i red spraywater va lves .
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2
C) C O M M E N T S
(1)
There are
th ree sec t ions of main s team superhea t ing; PRIMARY
uncontrolled),
SECONDARY
control led
by
t he
f i r s t
stage desuperheaters
lC,lD,lA,lB) and
TERTIARY [FINAL] control led
by
the second s t age
desuperheaters
A
and 28).
(2) The steam l ines from
each
side of the
secondary superhea te r
out le t
header
CROSS OVER before oin to the second s t age desuperhea te r s A
and 2B. [DESH lC,lD > 2A; lA,lB > 2B] The second s t age
desuperheaters 2A,
B
control the
t e r t i a ry
superhea te r
out le t
tempera tures
[West,
East].
(3) A separa te cont rol system
s
provided for each side of the
t e r t ia ry
[final] superheater . The
same
s e t value
s
used for each
system.
(4) Each
desuperheater has two
100 spray valves . 0nly ONE valve can
AUTO a t the same
time.
(5) A sepa ra te ins t ruc t ion
s provided for
the secondary superhea te r out le t
temperature control .
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B A N G
P A K O N G
3 4
D C I S M O D U L A T I N G
C O N T R O L S
O P E R A T I N G P R O C E D U R E
15 R E H E A T S T E A M T E M P E R A T U R E
[ G A S
R E C I R C U L A T I O N ]
GASRECRCT.INS 030992
SYSTEM
REHEAT
STEAM
CONT
VARIABLE
REHEAT
STEAM
TEMPERATURE
CONTROL DEVICE
GAS
RECIRCULATION
FANS 2A, 2B
CDR-125,
CDR-126
SET VALUE 540 DEG
SM
PB
RE HTR
GROUP
DISPLAY
009 REHEATER
TEMP
TX DEVN DISPLAY
095 STEAM TEMP XMTRS #2
A ) P E R M I S S I V E S
{1) No thermocouple dev ia t ion;
West/East.
2)
No
F i rs t
Stage
Pressure
t ransmi t te r
dev ia t ion
{3) No Boi ler Tr ip
4)
Selected
fan ON [Running].
B)
O P E R A T O R
A C T I O N
{1)
Check
thermocouples
[D isplay
095} f o r reasonable
value
and pa i r
agreement.
{2)
Select Group
Operat ion
Disp lay
009 [ RE HTR ]
and ENABLE subwindows
fo r
Burner T i l t and Gas
Rec i rcu la t ion
Fans.
{3) Adjust BIAS
se t t i ng
on Fan 2B
subwindow
to
zero [ cent re scale] .
{4) Adjust reheat steam
temperature
se t
po i n t
on Fan 2A t o requ i red value
[540 Deg
a t
normal
load].
5) Select AUTO on Burner T i l t subwindow.
6) Select AUTO on
Gas
Reci rcu la t ion Fans
subwindows.
7) Adjust R
Fan
bias
se t te r
i requi red
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-2 -
C )
C O M M E N T S
1)
The
maximum rehea t
steam se t point reduces as boi ler load decreases.
This maximum value
overr ides
the
opera tor
se t point . Refer
function
genera tor FG 78.
2) The
GR
Fan inle t vanes have a minimum posi t ion when in UTO mode. The
minimum var ies with load.
3) . The maximum
in le t
vane
posi t ion
is l imited by motor
current; the
maximum
value
i s
100
Amps. The maximum
current control overr ides
temperature control.
4)
Burner t i l t posi t ion
i s
control led as
a
function
of
boi ler load and
percentage o l fuel.
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B A N G
P A K O N G 3 4
D C I S
M O D U L A T I N G C O N T R O L S
O P E R A T I N G
P R O C E D U R E
16
R E H E A T
S T E A M
T E M P E R A T U R E [ S P R A Y S ]
RHSPRAYS.INS
030992
--------------------------------------------------------------------
SYSTEM
REHEAT
STEAM
\.
CONT VARIABLE
REHEAT STEAM
TEMPERATURE
CONTROL DEVICE REHEAT DESH
3A,
3B
[ACV-241,246,257,262]
SET VALUE 540
DEG
[+5 DEG
when
GR Fan AUTO]
GSM PB
RE HTR
GROUP DISPLAY
009
REHEATER TEMP
TX DEVN DISPLAY
095
STEAM
TEMP
XMTRS
2
A ) P E R M I S S I V E S
(1)
No
thermocouple
deviat ion [Monitor ON]
(2)
Modulate permit
from BVI
Logic ON
(3)
No
CLOSE
command
from
BVI
Logic
B)
O P E R A T O R A C T I O N
(1) Check thermocouples
for
reasonable
value
and
pair
agreement
(2) Select Group Operation Display 009. [Press
GSM
RE HTR ] and
ENABLE
subwindows for
required
control valves.
(3) Check
se t
point
[Gas
Recirculation
Fan
A subwindow]
(4)
Set
BIAS
adjustment
on
RH
spray
bias
subwindow
a t
zero.
(5) Select AUTO
for
requi red
RH spray
valves
(6) Adjust bias
se t t e r if required.
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2
C)
C O M M E N T S
(1) Under
normal
condit ions
the
Reheat
temperature
i s
control led by the
Gas
Recirculation
Fans.
The
s e t
point for
the
rehea t sp ray
valves
control ler
i s 5
deg higher than the GR
fans and
the valves are normally
closed. .
I f
the temperature i s more
than
5 deg above
the
se t point
the
spray
valves
open to provide back-up control. I f the
GR
fans are
manual the 5 deg bias
i s
removed and the sp rays
control
to the se t
point.
2)
Both desuperheaters
3A
and 3B must be selected to AUTO
valve of each pai r can
be
AUTO
Only
ONE