Post on 03-Apr-2018
7/28/2019 Boiler Mannual
1/49
INSTRUCTION FOR
PRODUCTBTG for Chhattisgarh 4X135
MW CPP, Raigarh
DOCUMENT NO.: 573-1-8601 - I -
DESEIN PRIVATE LIMITED
BTG for Chhattisgarh4 X 135 MW CPP, Raigarh
INSTRUCTION FOR PRODUCT
DOCUMENT NO.: 573-1-8601
REV. 0
JINDAL STEEL AND POWER LIMITED
SHANGHAI BOILER WORKS LTD.No.250 Huaning Road,
Minhang Shanghai,China
SHANGHAI ELECTRIC GROUP Co., Ltd.,No.8 Xingyi Road,Shanghai,China
7/28/2019 Boiler Mannual
2/49
INSTRUCTION FOR
PRODUCTBTG for Chhattisgarh 4X135
MW CPP, Raigarh
DOCUMENT NO.: 573-1-8601 - II -
DOCUMENT CONTROL SHEET
PROJ ECT: BTG for Chhattisgarh 4 X 135 MW CPP, Raigarh
CLIENT: JINDAL STEEL AND POWER LIMITED/ SHANGHAI
ELECTRIC GROUP Co., Ltd.,
DOCUMENT TITLE: INSTRUCTION FOR PRODUCT
DOCUMENT NO. : 573-1-8601
REV. NO. : 0
ENDORSEMENTS
0 2009.3.30
REV.NO.
DATE DESCRIPTIONPREP. BY
SIGN.(INITIAL)REVW. BY
SIGN.(INITIAL)APPD BY
SIGN.(INITIAL)
7/28/2019 Boiler Mannual
3/49
INSTRUCTION FOR PRODUCT
SG-460/13.7-M573
MODEL OF PRODUCT
460t/h Circulating Fluidized
Bed Boiler
NAME OF PRODUCT
573-1-8601
SERLES NO.
PREPARED BY DATE
CHECKED BY DATE
REVIEWED BY DATE
APPROVED BY DATE
SHANGHAI BOILER WORKS, LTD.
7/28/2019 Boiler Mannual
4/49
Catalog
0 INTRODUCTION..4
1 BOILER BASIS AND PERFORMANCE DATA..4
1.1 BOILER MODEL AND TYPE..4
1.2 BOILER TECHNICAL DATA...4
1.3 EXPECTED MAIN PERFORMANCE OF STEAM GENERATOR ( AT B-MCR OF DESIGN
COAL..5
1.4 FUEL..5
1.4.1COAL SPECIFICATION..5
1.4.2OIL FOR IGNITION AND AUXILIARY FIRING..6
1.5 STEAM AND WATER QUALITY7
1.6 SITE CONDITION.7
1.7 BOILER WORKING CONDITIONS...7
1.8 BOILER WATER VOLUME(M2)....8
2 BOILER OVERVIEW AND CONSTITUENT SYSTEM8
2.1 OVERALL BOILER INTRODUTION.8
2.2 STEAM AND WATER SYSTEM..11
2.2.1 FEEDWATER AND STEAM-WATER RECIRCULATION SYSTEM ( DRAWING 2.2.1;
DRAWING 2.2.2)12
2.2.2SUPERHEATED STEAM SYSTEM ( DRAWING 2.2.3 )13
2.2.3REHEAT STEAM SYSTEM ( DRAWING 2.2.4 )16
2.3 COMBUSTION SYSTEM17
2.3.1FUEL CRUSHING SYSTEM17
2.3.2COAL EXTRACTOR FEEDER AND CHUTE.17
2.3.3START-UP OIL IGNITOR..18
2.4 GAS AND AIR SYSTEM19
2.5 LIMESTONE AND BED MATERIAL SYSTEM.20
2.6 ASH RECIRCULATION SYSTEM..21
2.7 BOTTOM ASH EXTRACTION SYSTEM.21
7/28/2019 Boiler Mannual
5/49
2.8 TEMPERATURE CONTROL SYSTEM22
2.8.1SUPERHEATED STEAM TEMPERATURE CONTROL SYSTEM ( DRAWING 2.8.1 )...23
2.8.2REHEAT STEAM TEMPERATURE CONTROL SYSTEM23
2.8.2.1 EMERGENCY SPRAY WATER..23
2.8.2.2 GAS TEMPEARATURE CONTROL DAMPER..25
2.9 PIPING SYSTEM25
2.9.1PIPING FOR DRAINAGE, CHEMICAL FEED, REGULAR BLOWDOWN AND ACID
W A S H . 25
2.9.2PIPING FOR VENT, SAMPLING AND NITRIGEN INJECTION..26
2.9.3CONTINUOUS BLOWDOWN PIPING26
2.9.4SAFETY VALVE VENT PIPING..27
2.10MEASURING POINTS ARRANGEMENT..27
2.10.1 STEAM WATER SYSTEM MEASURING POINTS ARRANGMENT..27
2.10.2 GAS AND AIR SYSTEM MEASURING POINTS ARRANGMENT28
2.10.3 THERMAL CONTROL DESIGN DATA..28
2.11SOOTBLOWING SYSTEM..29
2.11.1 SOOTBLOWER ARRANGEMENT OVERVIEW29
2.11.2 SOOTBLOWER PIPING29
2.11.3 PROGRAMED CONTROL OF SOOTBLOWER..29
3 MAJOR PARTS..30
3.1 STEAM DRUM AND INTERNALS.30
3.2 WATER-COOLING SYSTEM30
3.3 REAR PASS HEAT-ABSORBING SURFACE.31
3.4 CYCLONE AND SEAL POTERROR
3.5 ASH COOLERERROR
3.6 BOILER FRAMWORK AND PLATFORMS & STAIRS33
3.7 SUPPORT AND HANGING FOR PRESSURE PARTS33
4 OTHER SYSTEMS..34
4.1 PROTECTION AGAINST ABRATION.34
4.2 SEALING.35
7/28/2019 Boiler Mannual
6/49
0. INTRODUCTION
Circulating fluidized bed (CFB) combustion is a new kind of high efficient, low
pollution clean coal combustion technology. The main feature of it is that the furnace
contains a large mass of bed materials. In the combustion process, these materials are
carried to the upper furnace by gas flow, separated from gas by the cyclones
connected to the furnace outlet and conveyed to the bed through non-mechanical
return valves. Thus realizes repeatable combustion of these materials. These materials
have a high density, large heat capacity and are well mixed and usually each kilo gas
can carry several kilo materials. Hence a high thermal coefficient of bed materials, a
wide range of boiler load and a large flexibility with respect to fuel quality. CFB
technology adopts a higher fluidizing speed than bubbling bed, so there is not an
obvious bed plane as is in the bubbling bed. Because of the turbulent flow and
recirculation of bed materials inside the bed, which enlarge the residence time of the
fuel, CFB has a higher combustion coefficient than the bubbling bed and can run
stably under low load without any auxiliary fuel.
The working temperature of CFB is usually between 850-900, an ideal range
for desulfurisation. In-Furnace Desulfurization technology is adopted. Limestone and
desulfurizer are fed into the bed. As the fuel and desulfurizer recirculate, repeating
low temperature combustion and desulfurization, at Ca/S circa 2, the desulfurization
efficiency can reach 90% and greatly decrease the SO2 emission. On the other hand,
CFB technology adopts stepped low temperature air supply combustion which keeps
the combustion process going under low excess air condition. Thus the produce and
emission of NOx is also greatly reduced. The CFB technology is also advanced in its
high combustion efficiency, capability of firing low rank fuel, wide range of boiler
load and convenience in ash reuse. So CFB is growing rapidly throughout the world.
As the environment protection requirement is getting more and more rigid, it is
commonly acknowledged that CFB is, so far, one of the most practical and feasible
combustion facilities.
Design of boilers of this project is made by SBWL using advanced CFB technology
based on the experience of design, manufacture and operation of tens of ultra high
7/28/2019 Boiler Mannual
7/49
pressure medium reheat CFB boilers. When firing design coal, boiler can operate
within 70%~100% rated load at constant pressure and within 50~100% rated load at
slide pressure. SH outlet steam can remain at rated parameter. When firing design coal
or check coal, boiler can remain stable firing within 30~100% rated load
1. BOILER DESIGN BASIS AND PERFORMANCE DATA
This is an island, half-open boiler, with complete steel structure and light steel roof on
the top. It is jointly fixed by support and hanging measures. The furnace floor
elevation is 9 m above ground. Here is some of the boilers characteristics: single
drum natural circulation, confluent downcomer, balance draft, thermal insulated
cyclone gas/solids separator, CFB combustion, air and water cooled fluidized bed ash
cooler, convection heat- absorbing surface designed in rear pass, superheater with two
stages of spray water atteperators, reheater temperature controlled by gas damper and
auxiliarily by emergency spray water device.
1.1 BOILER MODEL AND TYPE
Model: SG-460/13.7-M573
Type: super-high pressure intermediate reheat, single drum natural circulation,
circulating fluidized bed boiler
1.2 BOILER TECHNICAL DATA
ITEM UNITVWO
CONDITION
T-MCR
CONDITION
SH steam flow t/h 447.4 417.9
SH outlet steam
pressureMPa(g) 13.7 13.65
SH steam outlet
temperature
540 540
RH steam flow t/h 366.2 343.1
RH inlet steam pressure Mpa(g) 2.77 2. 6
RH outlet steam Mpa(g) 2.63 2.47
7/28/2019 Boiler Mannual
8/49
pressure
RH inlet steam
temperature
324 319
RH steam outlet
temperature
540 540
Feedwater temperature 247 245
1.3 EXPECTED MAIN PERFORMANCE OF STEAM GENERATOR (AT
T-MCR OF DESIGN COAL)
ITEM UNIT VALUE
Designed efficiency (LHV) % 81.87
guaranteed efficiency (LHV) % 81.5
Solid unburnt loss % 2.77
PH outlet dust concentration g/Nm3 50.2
1.4 FUEL
1.4.1 COAL AND ASH SPECIFICATION
135MWe CFB boiler design fuel
items description symbol unit design coal
Proximate analysis( As received basis)
1 Moisture (Total) Mar % 12.00
2
Fixed CarbonMad % 18.00
3
AshAar % 54.00
4
Volatile MatterVar % 14.00
5
Volatile Matter(dry ash free) Vdaf % 41.17
7/28/2019 Boiler Mannual
9/49
Qnet.ar kJ /kg 88126
LHV kcal/kg 2105
Qnet.ar kJ /kg 9630
7
HHVkcal/kg 2300
Ultimate analysis(As received basis)
1
CarbonCar % 24
2
Hydrogen
Har % 2.3
3
Oxygen (by difference)Oar % 6.5
4
NitrogenNar % 0.7
5 Sulphur Sar % 0.5
6
Total % 100
Analysis of ash ( Fly ash)
1
SilicaSiO2 % 60
2
AluminaAl2O3 % 24
3
Iron oxideFe2O3 % 8
4
ManganeseMnO2 % 0.03
5
Titanium oxideTiO2 % 1.5
6
Potassium oxideK2O % 0
7/28/2019 Boiler Mannual
10/49
7
sodium oxideNa2O % 0
8
Calcium oxideCaO % 4
9
Magnesium oxideMgO % 2
10
Sulphuric anhydrideSO3 % 0.25
11
Phoshorus PentoxideP2O5 %
12
Others% 0.22
13
Total% 100
Ash Fusion Temp. at oxidizing media
14
Initial deformation temperatureDT 1210
15
Hemi spherical temperatureST 1320
16
Flow temperatureFT 1350
Ash Fusion Temp. at reducing media
17
Initial deformation temperatureDT 1050
1.4.2 OIL FOR IGNITION AND AUXILIARY FIRING
This boiler use N0 light diesel oil for ignition and auxiliary firing. The coal
specification is as follow:
7/28/2019 Boiler Mannual
11/49
Sl.No. Particulars Unit (IS : 1593)
1. Flash point Deg. C min. 66
2. Viscosity @ 150C Maxi. Cst 2.0 - 7
3. Pour point 0C 12
4. Ash content by weight % max. 0.02%
5. Free Water content by volume % max. 0.05%
6. Sediments by weight % max. 0.1%
7. Total sulphur by weight % max. 1.8%
8. Carbon residence (Rams bottom) % wt
9. Approximate gross calorific value Kcal/kg In the order of
11000
10. SP gravity at 150C Max. 0.81
1.5 STEAM AND WATER QUALITY
To ensure the boiler outlet steam quality, the boiler water and steam quality must be
strictly controlled, especially the feedwater quality. The boiler feedwater, boiler water
and steam quality should be accord with GB/T12145-1999, The Standard Of Water
And Steam Quality For Power Plant Facilities And Steam Powered Equipments.
1.6SITE CONDITION
The condition as follow:
Project 4 x 125 + 20 % MW Thermal Power
Plant
Owners consultant DESEIN PRIVATE LIMITED,
DESEIN HOUSE,
GREATER KAILASH II
NEW DELHI 110048
Location Village:Dongamahua,Tehsil:
harghoda,
District Raigarh
Longitude:220653to 20713
7/28/2019 Boiler Mannual
12/49
Latitude:833145to 833226
Site Adjacent to existing coal washery of
JSPL.
Nearest Airport Domestic Raipur (350 KM)
International Kolkata
Nearest Seaport Kolkata
Nearest Railway Station Raigarh Railway Station on the
Mumbai Howrah main line 54 Km way
from the site
Access to site
Metrological data
A Altitude [Observatory] 280 m above MSL
B Ambient Temperature
I Maximum Temperature,
DBT
47.2 Deg C
II Minimum Temperature,
DBT
12.41 Deg C
III Maximum Temperature,
WBT
30.8 Deg C
IV Minimum Temperature,
WBT
20.6 Deg C
C RELATIVE HUMIDITY Varies from 19% to 85%
D RAINFALL
I. Annual Rainfall 1400 mm to 1600mm
II Tropical monsoon June to October
E WIND VELOCITY AND
PRESSURE [AS PER
IS:875-1987]
I. Basic wind speed. 50 m/sec at 10M above mean
retarding surface.
II Wind Direction North East
7/28/2019 Boiler Mannual
13/49
III. Terrain classification Category II
F Seismic Zone Zone III, as per
IS-1893, Part 1
1.7 Boiler working conditions
aUnit working mode
It can be run following compound slide pressure mode as well as constant
pressure mode.
bLoad kind of unit
The unit is designed to meet the needs of running safely and stably on
condition that the minimum steady-state combustion load without
oil-feeding is not large than 30% BMCR
cUnit annual working mode
The annual average working hours is no less than 7500 hours
dFeedwater regulation
2110 electric adjusting speed pumps are set for the unit, one is
operating , the other is backup. Feedwater operation desk has no main
adjusting valve, the 30% BMCR starting adjusting valve is set to meet the
requirement of start and low load condition.
eBypass settings
Two stage series-connedted bypass system is used to meet the function of
quick start and working substance return. The HP bypass flow capacity
according to the 60% BMCR of steam flow. The LP bypass flow capacity
according to the HP bypass flow adding the HP bypass desuperheater flow.
The bargainor shall consider protecting RH against dry-burning.
1.8 BOILER WATER VOLUME (M3)
ECO DRUMWATER
COOLINGSH RH TOTAL
73.22 30.70 68.90 108.22 107.24 388.28
2 BOILER OVERVIEW AND CONSTITUENT SYSTEM
2.1 OVERALL BOILER INTRODUTION
7/28/2019 Boiler Mannual
14/49
The boiler consists of steam drum, suspensory whole-membrane waterwall furnace,
thermal insulated cyclone separator, U-type seal pot duct and rear pass convection
heat-absorbing furnace. The drum, boiler water wall and rear pass cover wall are all
suspended. Cyclone and cyclone outlet duct are laid on steel beams. The primary of
economizer pipes are suspended on weight bearing girder by pipe clamps and is laid
on the steel beam through economizer frameworks column and ox leg structure.
U-type seal pot and tubular air preheater are supported by steel beams. An
independent steel structure is settled between column J and column K to support the
heavy primary economizer and tubular air preheater. Furnace and rear pass cover
superheater expands downward. There is an expansion center designed in boiler
waterwall, cyclone and rear pass respectively, the expanding parts are connected by
non-metal expansion joints. The figure of the boiler is eudipleural. Secondly span is
designed between left and right steel structure, upon which disposed platforms,
passages, economizer inlet pipes, main steam pipes, RH inlet pipes and RH outlet
pipes.
There are 2 water panels and 14 superheater screens on the upper furnace. The
panels are disposed symmetrically on left and right sides. Between the furnace and
the rear pass are two thermal insulated steel plate cyclones. The hull of the cyclone is
made of carbon steel plate. On the inner side of the hull is a layer of thermal
insulation material which is between the hull and the abrasion resistant layer. A
circular support is disposed between the cyclones column and the cone, laid on the
steel beam. Below each cyclone there is a non-mechanical U-type seal pot, at the
bottom of which there are fluidizing holes that fluidize the solids and return the solids
to the furnace. The rear pass is divided into two gas ducts by partition wall
superheater. In the front gas duct disposed the reheater, hung by superheater hanger
tubes and other hangers on the furnace top steel beams. In the back gas duct, the
high-temperature superheater (HTS) and secondary economizer is disposed
successively through the direction of gas flow. The pipes of HTS and secondary
economizer are attached to the rear wall superheater and partition wall superheater,
which transfer the load to the furnace top steel structure. In the superheater system,
7/28/2019 Boiler Mannual
15/49
primary spray water attemperator is set between the cold end and the hot end of the
superheater screen while secondary spray water attemperator is set between
superheater screen hot end and HTS. As CFB is characterized in its little gas
temperature difference, it is unnecessary to cross and combine the pipes from left and
right, and this arrangement is more practical. Gas temperature control damper is
disposed at reheater and secondary economizer outlet to control the gas flow passing
the reheater and thus control the outlet steam temperature. Emergency spray water
system is disposed on both sides of the reheater inlet ducts. When the steam turbine
high pressure cylinder outlet temperature goes above designed parameter, the
emergency spray water system will be actuated to ensure the reheater working safely.
Two stages of air supply are used in the boiler. Primary air goes through the bed
plate at furnace bottom and fluidizing holes into the furnace. Secondary air goes from
combustion chambers cone into the furnace. There are six coal-feed holes and six
limestone feed holes symmetrically disposed before furnace. At furnace bottom, the
steel plate made primary air chamber is hung on the lower header of waterwall. On-
bed start-up ignition is used and four (2 on either side wall) powerful torch oil guns
are disposed on the bed. And there is 4 drum ash cooler at the bottom of combustion
chamber.
Circulating fluidized bed combustion is used in this boiler. Under circa 880
bed temperature, the fuel, air and limestone mix in the dense-phase zone. Fluidized
coal particles burns and gives heat. Heat transfers from high temperature bed
materials and gas to waterwall surface. Limestone is calcinated into CaO and CO2.
CaO combines with SO2, which is a product of fuel combustion, and realizes
in-furnace desulfurization. The gas containing a large mass of bed materials goes
tangentially into the two cyclones from the furnace back wall outlet and is separated
from the solids by the cyclones. Then the clean gas leaves the center cylinder of the
cyclone and passes HTS (RH), ECO in the rear pass and the air preheater and is
finally released to air with its temperature drops to about 140. The solids collected
by the separators are returned to the furnace through the vertical pipes and the U-type
seal pots, hence the solids recirculated combustion. Because the solids (ash, unburnt
7/28/2019 Boiler Mannual
16/49
carbon, CaO and CaSO4) are repeatedly fired during the recirculation, the availability
of desulfurizer is greatly increased. The bottom ash (bottom ballast) is cooled in the
ash cooler disposed on both sides of the furnace and is discharged when its
temperature is below 150.
The mean elevation of the drum is 48220 mm. The distance from column G to K
is 37200 mm. The main span width is 21000mm and the secondary span width is
5000 mm.
2.2 Steam Water System
The steam water circulation system includes back pass economizer, drum,
generating surface (boiler water wall and water wall panels), back pass enclosure SH,
cold and hot platen SH, high temperature SH and RH.
2.2.1 Feedwater and Steam Water Circulation System (drawing 2.2.1,
drawing2.2.2)
There are 2 electric adjusting feed pumps, and the capacity is designed according
to 100%BMCR. The total 2 circuits are set for feed water: a DN225 main feedwater
duct with an electric gate valve and a non-return valve; a DN100 bypass feedwater
duct with an adjusting valve and 2 shut-off valves. When the boiler load is within the
30-100%BMCR, use the adjusting feed pump to control the feedwater; when the
boiler load is lower than 30%BMCR, switch to the bypass feedwater duct and use the
feed adjusting valve to control the feedwater.
7/28/2019 Boiler Mannual
17/49
Fig 2.2.1 feed water system
C1drum
E1ECON inlet tube
E2Low temp. ECON inlet header
E3Low temp. ECON
E4Low temp. ECON outlet header
E5ECON duct connection
E6: High temp, ECON inlet header
E7High temp. ECON
E8High temp. ECON outlet header
E10ECON riser tube
E11ECON recirculating tube
7/28/2019 Boiler Mannual
18/49
fig. 2.2.2 steam water circulating system
C1drum C2collective downcomer
C3C4C5C6water wall lower header
C7C8C9C10water wall tubes of furnace
C11rear wall outlet ring header
C12C13water wall upper headerC14water wall downcomer
C15water wall inlet header: C16water wall tubesC17water wall outlet heade
C18C19water wall steam-water riser tube
7/28/2019 Boiler Mannual
19/49
Firstly the feedwater flows from one side of the boiler into the primary
economizer inlet header. Secondly it flows upstream through 2 horizontal-arranged
economizer ducts. Thirdly after it is heated, it flows into the second stage economizer
ducts. Finally it converges at the economizer outlet header, and then flows through 2
connecting ducts into the drum. One economizer recycle duct with 1 electric shut-off
valve and 1non-return valve is set between the drum and the header at the primary
economizer inlet. When the boiler is starting up, turn on the electric shut-off valves in
the duct. A natural circulation circuit is established between the economizer and drum,
which prevents the dead water evaporation in the economizer and assures the safety of
the economizer when the boiler is starting up. When the feedwater is enough, the
electric shut-off valves in the duct can be shut off. The recycle duct capacity is
designed according to 5%BMCR.
The steam water circulation system includes drum, big diameter downpipes,
water wall panel downpipes, water wall, water wall panels and lead-out ducts. The 4
356 big diameter downpipes leaded from the water space of the drum are connected
with the lower headers of water wall at the front, left and right furnace walls
separately. According to the combustion characteristics of CFB, the heat load
distribution in the furnace is very homogeneous. So the separating circuit is not set in
the water wall design, and the tee junction is used to connect the lower headers of
water wall into a ring circuit and the inside medium is connected. The water wall is
made of membrane wall containing 63.5bare tube and flat iron. The boiler water is
continuously heated when it flows up along the membrane waterwall, and the
steam-water mixture is formed gradually. The steam-water mixture flows from the
headers at the upper outlet, and then it flows through 36 168 steam-water lead-out
pipes to the drum. At the same time, the water is supplied from 2 219water wall
panel downpipes leaded from the water space of the drum to 6 water wall panels at the
upper of the furnace. The steam-water mixture formed in the water wall panel flows
through 4 168 steam-water lead-out pipes to the drum. The steam-water mixture
is well separated in the drum by cyclone and corrugated plate. The separated water
goes into the drum and water circulation again, and the purified steam goes into the
SH system by steam-water lead-out pipes at the furnace roof.
7/28/2019 Boiler Mannual
20/49
The circuits of water wall and water wall panels are two separated parallel ones,
and the flow distribution between them depends on their own surfaces, furnace heat
load and water circulation coefficient. Once the flow distribution is determined,
specifications and quantities of downpipe and lead-out pipe can be selected according
to the outcome of water circulation calculation. Thus, the reasonable water circulation
coefficient is guaranteed, and the water circulation is stable and reliable.
2.2.2 Superheated Steam System (drawing 2.2.3)
The saturated steam leads out from the top of the drum, and it flows through 8
168 connecting ducts into the header above the left and right side enclosure SH.
Secondly it flows into the header under the side enclosure SH. Thirdly it convergesthrough header at the header under the front enclosure SH. Fourthly it flows
through front enclosure SH, roof enclosure SHrear enclosure SH, parallel-arranged
pendant tube SH and division wall enclosure SH. Fifthly it converges at the header
above the division wall enclosure SH. Sixthly it flows through 2 273 connecting
ducts into the header at the inlet of cold panel SH. Seventhly it is heated when it flows
along the heating surface and then flows into the primary attemperator. Eighthly it
flows into the hot panel SH, and then it is attempered by the second stage attemperator.
Ninthly, it flows through 2 324 connecting ducts into the high temperature SH in
the back pass and is heated to the required temperature. At last it flows through the
main steam duct from the header at the outlet of the high temperature SH into the
high-pressure tank of the steam turbine. The flow of steam is as flows:
saturated steamleft and right side enclosure SHfront enclosure SHroof
enclosure SHrear enclosure SHdivision wall enclosure SH, pendant tube SH
cold panel SHprimary attemperatorhot panel SHrear panelsecond stage
attemperatorhigh temperature SHmain steam outlet
7/28/2019 Boiler Mannual
21/49
fig. 2.2.3 SH steam system
S1saturated steam riser tube S17primary SH inlet header
S2clad side wall upper header S18primary SH panel tube
S3clad side wall tube S19primary SH panel middle header
S4clad side wall low header S20primary SH panel tube
S5clad front wall low header S21primary SH panel outlet
S6clad front wall tube S22primary desuperheaterS7clad front wall upper ring header S23secondary SH panel inlet header
S8S9clad roof & rear wall tube S24secondary SH panel tube
S10clad rear wall low header S25secondary SH panel middle header
S11connecting pipe S26secondary SH panel tube
S12partition low header S27secondary SH panel outlet header
S13partition tube S28secondary SH outlet header tee
S14hanger tube S29secondary desuperheater
S15partition wall upper header S30high temp. SH inlet header
S16connecting pipe S31high temp. SH tube
S17primary SH panel inlet header S32high temp. SH outlet header
7/28/2019 Boiler Mannual
22/49
S33high temp. SH outlet connecting pipe
2.2.3 Reheated Steam System (drawing 2.2.4)
The steam discharged from the high-pressure tank of the steam turbine flows
through 2 426connecting ducts into the RH. The RH is arranged in one stage,
which comprises 4 sets of tube. All sets are arranged in the front duct of back pass and
are suspended on the SH pendant tube. The reheated steam is heated and flows
through 2 457 connecting ducts into the inter median cylinder of turbine. An
emergency attemperator is set on the duct of RH inlet. When the temperature of theexhausted steam from HP cylinder of turbine is higher than the design value, the
emergency attemperator will be started to lower the temperature of reheated steam
and thus guarantee the safe operation of RH. The temperature of reheated steam is
attempered by flue gas baffle at the outlet of back pass.
Fig 2.2.4 RH steam system
7/28/2019 Boiler Mannual
23/49
R1R2RH emergency spray R5RH outlet header
R3RH steam inlet pipeRH inlet header R6: RH steam outlet pipe
R4RH tube
2.3 Burning System
2.3.1 Fuel Crushing System
Raw coal is crushed through two stage crushers. The requirement of grain size at
the outlet of the last-stage crusher is seen in Drawing 2.3.1. Raw coal with the eligible
final grain size goes into the big coal bunker, and is conveyed by a coal feeder to the
above of coal chute. The sweeping air is set under each coal chute so that the coal can
be fed into the furnace homogeneously.
2.3.2 Coal Feeder and Coal Chute
Six coal feeders are arranged in front of furnace. They connect the big coal
bunker and coal chute and convey the crushed coal to the inlet of coal chute according
to the boiler load requirement. Considering the repair of coal feeder and fuel change,
the feeder design capacity should have 100% reserve margin.
In the coal chute, the coal arrives at the feed port of furnace by gravity, and
finally goes from the front water wall into the furnace. The sweeping air is provided at
the feed port of furnace so that the air cushion can be formed in the duct and at the
turning corner of duct. It makes coal flow fluently, have some kinetic energy and
distribute evenly, and it prevents coal local piling. The material of coal chute is
stainless steel tube material of 45710mm, and the lower part of it is the ceramic
lining tube of internal diameter 433mm, which prevents coal clogging. Expansion
joint is set on the perpendicular section of coal chute. It absorbs the heat displacement
of water wall and the heat displacement is as follows:
Item UnitFeed
port#1
Feed
port#2
Feed
port#3
Feed
port#4
Feed
port#5
Feed
port#6
Down
mm 140 140 140 140 14014
0
Front of Furnacemm 20 20 20 20 20 20
Leftmm 28 18 7 / / /
7/28/2019 Boiler Mannual
24/49
Right
mm / / / 7 18-2
8
Note: The feed ports are numbered from left to right, and the expansion center of
boiler takes the symmetrical centerline of boiler as origin.
To prevent backflow of gases from the furnace to the coal feeder, a cold air, used
as sealing air to protect the coal feeder, should be leaded from the cold air duct at the
outlet of primary air fan to the coal feeder and coal chute. The inlet of coal feeders
sealing air is set at the inlet of coal feed, and the inlet of coal chutes sealing air is set
under the sluice valve.
7/28/2019 Boiler Mannual
25/49
2.3.3 Start-up Oil Burner
There are 4 above-bed start-up burners (the capacity is 43000kg/h) in the boiler.
The oil gun is the one with pressure air atomization, center return flow oil, wide
control band and convenient operation. The pressure of main line feeding oil is
1.8MPa and the flow is 12t/h. The oil system at the front of furnace takes the
pressured air as the sweeping medium, and the sweeping pressure is 0.75MPa and the
temperature is 250.
The ignition oil gun is the advance and retreat type one and there is some space
between gun and anti-abrasion sheet surface inside the furnace. When the boiler
operates normally, the above-bed ignition oil gun can be retreated to the outside of
furnace. At the same time, certain amount of cold air is maintained, which prevents
burners burnout. The high energy arc ignition device and flame detector are supplied
with the above-bed ignition oil gun.
7/28/2019 Boiler Mannual
26/49
When the boiler starts up coldly, the start-up bed material is put into the CFB.
Firstly turn on the primary air fan and make bed material little fluidized. Secondly
turn on the secondary air fan, put the ignition oil gun into use and heat bed material
according to the start-up chart. Thirdly after the bed temperature increases to 620C
and keeps stable, feed the coal to guarantee the reliability of ignition. During the coal
feeding, small amount of coal is fed at interval at first. And after the coal is fired, feed
more coal and start the feed device continuously.
2.4 Flue Gas and Air System
The boiler is a balance draft one, and the pressure zero point is set at the inlet flue
gas duct of cyclone. The circulation of material in CFB is started and maintained by
FD fan (including primary and secondary air fan) and ID fan. The combustion air
from the primary air fan goes through the air heater and primary air preheater in line
and then splits in three parts: the 1st one is as fluidizing air that goes into the air
plenum at the furnace bottom and through the furnace capped nozzles, and it fluidizes
the material on the bed and forms the upward solid circulation; the 2nd one is as
sweeping air extracted through a trunk duct from the air plenum to the front of
furnace and then 6 branch ducts from the trunk duct to the coal chute, and the total
flow is 18600Nm3/h; the 3rd one is a high pressure cold air extracted from the cold
air duct behind the outlet of the primary air fan as sealing air for coal feeder and coal
chute, and the total flow for coal feeder is 2520Nm3/h and the total flow for coal
chute is 672Nm3/h. The secondary air is heated when going through the air heater and
primary air preheater in line, and then it is leaded to the front of furnace. Several
branch ducts leaded from the air plenum goes from the upper of front, rear wall and
emulsion zone of furnace to the furnace firing chamber. It is also used as cooling air
for oil gun. When the boiler load is 100%B-MCR, the proportion between primary air
and secondary air is about 55:45. When the boiler load decreases gradually, the
proportion between primary air and secondary air changes accordingly and the
proportion of primary air increases gradually. The details are seen in Collection
Chart of Boiler Thermal Calculation.
The flue gas with solid particles goes through the inlet duct of cyclone from the
furnace into 2 cyclones tangentially. In the cyclone, coarse particles are separated
from flue gas, and the flue gas goes through the cyclone into the back pass. The flue
7/28/2019 Boiler Mannual
27/49
gas is cooled by the convection heating surface. Then it goes through the tubular air
preheater into the dust collector and fine particles are left out of flue gas. Finally it is
sent into the stack by ID fan and discharged to the atmosphere.
One portion of high pressure fluidizing air is used as fluidizing air for U seal pot;
the other one is used as greasing air for erect duct and return duct of seal pot. One
portion of FBAC fluidizing air is used as fluidizing air for FBAC; the other one is
leaded to the outlet of furnace slag-drip opening and used for sweeping tapered valve
hood at the top of slag-drip valve shaft. It assures the smooth feeding of FBAC.
2.5. Bed material system
Start-up bed material feed-hole is designed at anabatic vertical pipe of two
U-type seal pots, start-up bed material bin is arranged in boiler proper structure, the
height of strat-up bed material bin shall be above the level of start-up bed material
feed-hole, to ensure bed material can flow into seal pot of itself. Start-up bed material
bin is also arranged at front of furnace and connected with feeder, bed material is
filled into furnace by using feeder and feed chute. Start-up bed material is usually
adopt sand, or adopt coal ash is burned off, grain requirement of bed material see
2.5.2 bed material grain distribution.
7/28/2019 Boiler Mannual
28/49
Bed material injection quality is 13600kg before boiler start-up, including bed
material for furnace, seal pot and ash cooler. If CFB slag as bed material in furnace,
the height is about 880mm; if bed material is sand, the height is about 760mm.
2.6 Ash circulation system
Ash circulation system is composed of furnace, cyclone and U-type seal pot.
Primary air enter into emulsion zone at furnace bottom through nozzle arranged at
water-cooled air distributor, to make material in furnace fluidize, HT material, coal
and limestone mix completely, and complete burn and desulfurize in emulsion zone.
Large grain material flow into emulsion zone along boiler water wall after it is
fluidized and suspend at certain height; small grain material leave furnace carried by
flue gas, tangential enter into cyclone with high speed through nonprismatic cyclone
inlet duct. Flue gas rotate with high speed in cyclone, solid grain that its quality is
7/28/2019 Boiler Mannual
29/49
large is thrown cyclone inside wall because of centrifugal force effect and flow into
seal pot along inside wall, but small solid grain enter into boiler back pass by flue gas
through vortex at cyclone upper. Cyclone design is adopted ALSTOM company
mature and advanced technology, separate rate is more than 99.5%, can separate HT
solid material from gas flow, then enter into furnace through seal pot to maintain high
grain concentration in furnace and ensure large heat surface heat-transfer rate, ensure
that fuel and desulfurizing agent can completely burn off and chemical react in
multi-circulation. Truly materialize CFB boiler high efficient and clean combustion
technology.
Ash circulation ratio is about 30, bed pressure in furnace emulsion zone can
reflect furnace ash concentration indirectly, control ash concentration at reasonable
level by ash discharge at furnace bottom.
2.7 Tapping slag and ash discharge system
Ash content of coal is discharge as slag at furnace bottom and as fly ash at boiler
back-end. The quotient of each kind of ash content is different according to coal
granularity, ashing feature. Based on this boiler design coal and coal granularity into
furnace, slag is 45% in total ash, mean granularity is about 500um, fly ash is 55% in
total ash, mean granularity is about 30um.
Four ash coolers is arranged in this boiler, set at the furnace bottom and arranged
at 0m layer, adopt water cool as main cooling form. The total ash of boiler is .
16091kg/h, The designed ash discharge amount of each ash cooler is 50% in total ash.
Only one ash cooler can meet the needs of normal operation for boiler. The feed slag
temperature is 880, and the tapping spout temperature is 110.
2.8 Attemperation system
2.8.1 SH steam attemperation system
7/28/2019 Boiler Mannual
30/49
fig 2.8.1 SH steam attemperation system
SH steam attemperation system is divided into two stages. Primary spray
desuperheater is arranged between cold end outlet and hot end inlet of platen
superheater to control steam temperature into hot end inlet of platen superheater.
Primary desuperheater is one, proper size is32428, material is SA335-P12,
spray tube adopt flute-type structure. Secondary spray desuperheater is arranged at
connection pipe between hot end outlet of platen superheater and HT superheater inlet
to control steam temperature of HT superheater outlet, and make SH steam
7/28/2019 Boiler Mannual
31/49
temperature attain design value. Secondary desuperheater is two, proper size is324
28, material is SA335-P12, spray tube adopt flute-type structure. Water source of
desuperheated water is introduced to the front of HP heater and feedwater operation
platform, the max. spray water amount in this system has been considered
desuperheated water amount needed in high preesure heater out of servicedrawn
point temperature of desuperheated water is 172, pressure is about 16Mpa(g) under
B-MCR condition.
See drawing 820573-E1-06 (superheater desuperheated water pipeline), the
interface position of desuperheater water pipeline and design institute is at the front of
column G. adopt reducing tee to divide into three branch pipe at the end of
desuperheated water manifold, one cutout valve is set at each branch pipe, this valve
can be closed under boiler emergency condition to separate electric control valve
behind it. Set another cutout valve behind electric control valve, close this valve when
control valve is maintained. Set one drainage (backwash) pipeline between cutout
valve and control valve, can termly check cutout valve is leakage under closed
condition or not. Spray water control valve adopt imported produce, can meet the
requirement under various conditions of boiler.
Flow nozzle is set at each branch pipe of desuperheated water pipeline.
2.8.2 RH steam attemperation system
Gas tempering damper is main in RH steam attemperation, emergency spray
water is only used at non-normal condition, and viz. emergency spray water is used
when RH steam inlet temperature is higher than design value to ensure reheater safety
2.8.2.1 Emergency spray water
Two emergency spray water devices are apart arranged at left and right side pipe
of heater inlet, water source comes from pump pigtail, the pressure is about
6.0Mpa(g), temperature is 172 under B-MCR condition. At desuperheated water
manifold, adopt reducing tee to divided pipeline into two parallel circuits, and apart
enter into emergency desuperheated spray water desuperheater at two sides of boiler.
One cutout valve is set at each branch pipe; this valve can be closed under boiler
emergency condition to separate electric control valve behind it. Set another cutout
7/28/2019 Boiler Mannual
32/49
valve behind electric control valve, close this valve when control valve is maintained.
Set one drainage (backwash) pipeline between cutout valve and control valve, can
termly check cutout valve is leakage under closed condition or not. Spray water
control valve adopt imported produce, can meet the requirement under various
conditions of boiler. Flow nozzle is set at each branch pipe of desuperheated water
pipeline This system sees drawing 2.8.2.
Fig 2.8.2 RH spray desuperheater system
2.8.2.2 Gas tempering damper
7/28/2019 Boiler Mannual
33/49
Gas tempering dampers are apart arranged below reheater duct and HT
superheater duct, gas damper in every duct is divided into left and right group, 4
groups in all, the type is separating-chamber. Damper of every group at reheater side
is composed of 7 pieces of blade; at superheater side is 3 pieces of blade, and
combined by the tie rod. The tie rod is laid upon the damper to avoid abrasion. The
damper is controlled by the electric actuator via the tie rod; Control the damper
according to the following suggestions:
(1) Limiting position protection: the limiting inclination () of the damper and
level is 15. (damper close completely is 0 )
(2) Operation with normal load: the damper regulates the temperature of the
reheated steam. When regulating, the damper of the RH flue gas duct and SH flue gas
duct should be turning at the same time but in the opposite direction, and the sum of
these two dampers angle should be always kept as 90.
Gas quotient of duct of reheater side under various load condition sees boiler heat
calculation data sheet.
(3) The blow stage before the boiler start-up: The dampers of gas flue are
completely opened.
(4) The start-up stage: is 15at the RH side and 75at the SH side, so most
flue gas flow through the cold SH. This can not only protect the RH, but also increase
the temperature of the superheated steam quickly, and then reduce the start-up time.
2.9 piping system
Boiler piping system is mainly composed of drainage, blowdown, vent,
exhaust, etc. pipeline with related pipe and valve.
2.9.1 Drainage, periodic blowdown chemical feed , acid wash pipeline17 lines are set in boiler drainage pipeline in all, viz. economizer inlet pipe 1,
economizer outlet header 2, ring lower header under enclosure front wall 2, both ends
of lower header under enclosure rear wall 2, medium header of platen superheater
cold end 1, medium header of platen superheater hot end 1, HT superheater inlet
header 2, pipe at superheater outlet 2, reheater inlet 2, reheater outlet 2, 2 cutout
valves are set in each pipeline in series, valve adopt DN20. all drainage pipeline is
connected to boiler operation layer.
4 periodic blowdown lines are arranged at water wall ring lower header, one
7/28/2019 Boiler Mannual
34/49
periodic blowdown pipeline is set at every water wall panel lower header. Every
pipeline is arranged with 1 imported electric periodic blowdown valve, in series with
one cutout valve before it, can close cutout valve under boiler emergency condition to
isolate electric periodic blowdown valve. Finally, above 6 periodic blowdown pipeline
converge in periodic blowdown manifold header, manifold header outlet is arranged
with high pressure difference throttling valve and electric periodic blowdown valve in
series to reduce inlet and outlet pressure difference of blowdown valve, to improve
the condition at operation, and to extend its life. The quality of the steam and water in
operation is controlled by continuous blowdown. Only when the boiler first start-up or
start-up after overhaul, or the continuous blowdown cannot maintain the quality of the
steam and water by some reasons, the periodic blowdown system will be turned on.
The support and suspender of the periodic blowdown duct should be designed
properly and meet the requirements of the expand displacement and the periodic
blowdown duct wont oscillate when it is turned on.
Besides above normal drainage, another emergency drainage pipeline is set in
boiler, introduced boiler operation layer from drum bottom. Pipeline is arranged with
two DN3electric cutout valves, immediately open this valve when drum water level
exceed normal level, after reach normal level, close the valve. Chemicals feed
pipeline is arranged at the front of boiler, connected to drum front of bottom, one
non-return valve and one cutout valve are arranged in series in this pipeline. One acid
wash pipeline is set at waterwall front and rear wall header.
2.9.2 Vent, nitridation ,samplingpipeline
10 vent pipelines are set between economizer and HT superheater, 2 vent
pipelines are set at reheater outlet, and 2 cutout valves in series for every pipeline.
There is 10 nitrogen injections in all set at economizer outlet pipe, saturated steam
riser tube, the connection pipe between clad SH and platen SH, primary stage
desuperheater, connection pipe between platen superheater and HT superheater and
reheat outlet pipe, nitridation pipeline is set between two cutout valves of vent
pipeline, 1 cutout valve is arranged at each pipeline.
Shall open vent valve and drainage valve before boiler ignition, close vent valve
and part drainage after having certain pressure, dont close superheater vent valve
until unit is on-line, avail to control main steam temperature and pressure, close
reheater vent valve and drainage valve before condenser in vacuum.
7/28/2019 Boiler Mannual
35/49
Nitridation pipeline is for boiler shutoff for long time (exceed one month), boiler
adopt nitridation or other method. Boiler shall be draughty when filling nitrogen or in
nitridation maintenance period.
It is 8 lines for boiler sampling, viz. sampling of feedwater, boiler water, saturated
steam, SH steam and RH steam. Feedwater sampling is set at feedwater manifold,
boiler water sampling is set at continuous blowdown pipe at drum both ends, 2 points
are set at steam riser pipe for saturated steam sampling, 2 points of SH steam is set at
HT SH outlet pipe, two cutout valve are arranged at each pipeline.2 points are set at
RH inlet pipe for RH steam sampling, one cutout valve is arranged at each pipeline.
2.9.3 Continuous blowdown pipeline
The continuous blowdown converge in one line after it is connected from the
downside of the drum both ends, mainly for controlling and keeping boiler water
quality, the capacity of blowdown shall accord to boiler water chemical analysis.
Continuous blowdown pipeline is arranged with one imported air-operated valve,
another high pressure difference control valve in series to reduce the pressure
difference of the periodic inlet and outlet of the air-operated valve, to improve the
condition at operation, and to extend the life. The front and back of air-operated valve
are also arranged with one electric cutout valve while set bypass for air-operated valve
service
2.9.4 Safety valve discharging pipe
Overpressure protection of boiler pressure part is realized by setting certain
safety valve. There are 3 safety valves for SH steam system, thereinto 2 valves for
drum, one for superheater outlet pipe, additionally set 2 EBV valves in series at
superheater outlet pipe (each for left and right). pipe. There are 4 safety valves for
RH steam system, thereinto 2 valves for reheater inlet pipe, 2 valves for reheater
outlet pipe. There are 9 silencers in all according to connection meeting minutes
requirement to design silencer and discharging pipe, thereinto 2 silencers for drum
safety valve, one for superheater safety valve, two for superheater EBV valve, 2 for
reheater inlet safety valve, 2 for reheater outlet safety valve. All discharging pipes are
connected from safety valve to boiler roof upper side.
2.10 Measuring point
2.10.1 Measuring point arrangement for steam-water system
Whole steam-water system is arranged with various function instrument
measuring points according to different part and requirement. Besides local
7/28/2019 Boiler Mannual
36/49
monitoring pressure gauge, other pressure measuring points of steam-water system
shall be arranged with primary valve, the owner can set control instrument according
to requirement, 5 pressure measuring points for drum, two of these for local
monitoring. SBWL supply whole set of valve and pressure gauge, other pressure
measuring point is supplied with primary valve, the owner can introduce to anywhere
according to checking, protection, adjustment etc. requirement.
It is necessary condition that keep boiler normal water level for natural circulation
boiler safe operation. Usually set certain number water gauge for monitoring method.
This boiler adopt dual-color water gauge arranged at drum both end head as for water
level local monitoring, the visual height of water gauge is 550mm, one TV monitor is
set prior to each water gauge, can interlaced monitor water level of drum both ends by
switching device. One electric connecting point water gauge set at drum left head is
for water level monitoring and alarm. Boiler phase-down automatically (see sheet
2.10.1) when water level exceed protection limit value. Additionally one high level
electric connecting point water gauge is arranged at drum right side head, besides
have effect as water gauge at left side head, also can meet drum full water level
checking requirement when boiler shutoff.
Sheet 2.10.1protection limit value for drum water level control
Level mmBelow drum
Centerline
150
50 100 150 175 230
Measuring
point for
Thermal
control
interlock
Normal water
level
Allowable
water level
Audible
alarm
Emergency
discharge
Phase-
down
Phase-
down
4 water level balance vessels is set at head of drum both ends for checking, protection
and adjustment under boiler operation.
Drum is very important pressure part for boiler; boiler start-up and shutdownspeed will affect drum thermal stress amplitude, so affect drum life breakage, and so
7/28/2019 Boiler Mannual
37/49
control start and shutdown speed according to the requirement of boiler start-up and
shutdown curve strictly. 4 couples outside wall temperature measuring points and 2
couples inside wall temperature measuring points are arranged along drum axes
direction, avail to monitor drum wall temperature difference under boiler start and
shutdown. The temperature difference between drum upper wall and below wall is not
less than 50 and same as to inside wall and outside wall when boiler cold start.
2.10.2 measuring point arrangement for gas and air system
Besides gas temperature, pressure, sampling measuring point as same as
pulverized fuel boiler are arranged at CFB boiler, also set a lot of furnace pressure
difference, bed temperature, fluidizing air pressure, air flow measuring point to
provide needed monitoring method and protection measure, and to ensure boiler
safety operation.
6 couples gas pressure difference measuring point are apart set furnace below,
medium upper and primary air box, pressure transmitter convert pressure signal into
electric signal, connect with slag valve actuator at ash cooler inlet. Slag valve actuator
will operate; quicken tapping slag to make furnace bed pressure keep in regulated
range when furnace pressure difference exceeds set value. Additionally set 4 pressure
measuring points and 8 pressure switches interface in furnace, furnace pressure set
value is +20.8KPa, -8.7KPa, subatmospheric pressure zero is set at furnace outlet. 2
gas pressure measuring points are set in cyclone outlet duct, can measure cyclone
resistance loss. 2 pressure measuring points for material level are set every seal pot
vertical pipe to monitor material level in vertical pipe and alarm when material level
is too high or too low.
22 gas temp. measuring points are set in furnace, 8 gas temp. measuring points
are set in cyclone inlet duct and outlet duct in all, these measuring points are in HT,
high speed and high ash concentration zone, so shall select wear-resisting
thermocouple to ensure certain service life.
Temp. and pressure measuring point is set at all convection heat surface in rear
pass, additionally, 2 oxygen measuring points and 14 gas sampling points are set at
primary economizer outlet, 5 gas sampling points are set at air preheater outlet duct,
7/28/2019 Boiler Mannual
38/49
design institute confirm its position.
Set enough material temp. and pressure measuring points in seal pot to ensure
material fluidize well and return to furnace successfully, and need to monitor HP
fluidizing air flow. set air flow gauge in all HP fluidizing air branch pipe and air-filled
pipe, to control air injection in design range.
2.10.3 thermal control design information
SBWL supply following information. Confirm position, range, number, use,
supply range of thermal control measuring points and alarm value and protection
value of boiler operation in these information for design institute thermal control
speciality:
P&ID drawing for boiler system
hole measuring point layout drawing
thermal control measuring point arrangement position and description
boiler control system information
information for start burner oil system at front of furnace
information for electric actuator of steam-water system valve
2.11 Sootblowing system
Reasonably set soot-blower is important auxiliary method for boiler safety and
reliable operation and to prevent heat-transfer effect due to heat surface fouling.
Sootblowing system is composed of pressure-reduction station, soot-blower,
sootblowing pipe and drainage pipe, sootblowing steam source come form platen
superheater cold end outlet pipe prior to primary desuperheater, steam pressure drop
to design value through pressure-reduction station is sent to each soot-blower.
Sootblowing steam come form auxiliary steam source system in boiler start stage,
require that steam temp260, pressure is 0.5~0.7MPa, flow 2m3/h, design
institute take charge of auxiliary steam source design.
2.11.1 soot-blower arrangement
Because boiler water wall of CFB boiler has strong capacity to clean ash by itself,
so not set soot-blower in furnace.
Only install soot-blower at convection heating surface of boiler rear pass ,
7/28/2019 Boiler Mannual
39/49
thereinto 2 pieces of long-length retracting type steam soot-blower are installed at
under first layer tube group inlet of superheater, 2 pieces of long-length retracting
type steam soot-blower are installed at secondary economizer topper tube group inlet,
2 pieces of semi-retracting type steam soot-blower are installed at under tube group
inlet of secondary economizer. 6 pieces of long-length retracting type steam
soot-blower are installed at the topper three layer tube group inlet of reheater , 2
pieces of half retracting type steam soot-blower are installed at under tube group inlet
of reheat ; 16 pieces of land-rotary steam soot-blower are installed at under & upper
tube group inlet and front & rear wall inlet of primary economizer. 12 pieces of
half-retracting type steam soot-blower are installed at each tube group inlet of tubular
preheater.
2.11.2 Sootblowing pipe
sootblowing pipe include all equipments and pipe between superheater extraction
opening and all soot-blower, steam pressure drop regulated value through
pressure-reduction station, then enter into each soot-blower, auxiliary steam source is
connected behind pressure-reduction station. Sootblowing pipe is supplied by
soot-blower manufactory.
2.11.3 Sootblowing program control
Soot-blower program control can be realized by PLC. System can operate
automatically, remote operate and simulated operate in control room; can realize local
manual operation on site. soot-blower operate in couple according to gas flow
direction, first upstream then downstream, the longest working time of single
soot-blower is about 5min.
3. Main part
3.1. Drum and internals
drum inside diameter is 1600mm, wall thickness is 145mm, material is SA299,
straight length of shell is around 14200mm, total length including head length is about
16000mm, 4 couples measuring socket for outside wall temp. and 2 couples
measuring sleeve for inside wall temp. are set in drum wall for controlling temp.
7/28/2019 Boiler Mannual
40/49
difference of upper and below wall in hydraulic test and operation.
Drum normal water level is set 150mm under drum centerline, the distance
between highest and normal water level is +50mm, and the distance between lowest
and normal water level is -50mm. Drum internals is composed of separator, feedwater
washing orifice plate, top uniform flow orifice plate. Separator diameter is315mm,
number is 54, connect with each connection box, deflector is installed at separator
inlet to improve steam separation effect. The capacity of single separator is about 9t/h
under B-MCR condition. Washing orifice plate is arranged above separator, it is keep
30~40mm thickness water at washing orifice plate, separated steam through washing
orifice plate cleaned by 50% feedwater came form economizer, part salt dissolve in
washing water, washed steam take uniform flow through top multi-orifice plate,
finally clean steam introduced into superheater system by saturated steam riser pipe.
Steam-water mixture is introduced from water wall and water panel into drum by
36 pieces pipes which diameter is 168.
4 pieces downcomer which diameter is356 come form drum supply water to
boiler water wall, in addition 2 pieces downcomer which diameter is219 supply
water to 2 pieces of water panel at furnace upper.
Boiler feedwater is introduced from economizer outlet header into drum by 2
connection pipe which diameter is219, 12 branch pipe which diameter is108,
thereinto 50% feedwater flow through washing orifice plate, another 50% is directly
introduced into drum water room.
Saturated steam is educed from top of drum, then is introduced into enclosure
wall superheater upper header at rear pass both sides by 4 pieces of pipe which
diameter is168.
Two spring safety valves is arranged at drum both ends, also some needed
nozzles for continuous blowdown, chemicals feed, emergency discharge, recirculation
of start and shutdown, water gauge and balance vessel are arranged at drum.
Boiler steam and water quality shall accord with the requirement of
GB/T12145-1999water and steam quality standard for heat power unit and steam
7/28/2019 Boiler Mannual
41/49
power equipment .
3.2. Water-cooling system
furnace heightwidthdepth is 35400mm14795.5mm7683.4mm, boiler
water wall tube all adopt diameter is63.56.5, material is SA-210C tube, bare tube
and flat steel compose membrane wall, the pitch of tube is 88.9mm, arrange 166
pieces of front wall as same as rear wall, 86 pieces of tube for left side wall as same as
right wall. The excellence of membrane wall is: good sealing performance, reducing
furnace leakage, and increasing economical efficiency, wall setting structure and
support is easy and can adopt light wall setting. Multi-layer buckstay are arranged
along the height direction of boiler water wall, increase whole furnace stiffness and
keep water wall from deformity due to positive pressure combustion in furnace.
Pressure capacity of buckstay of combustion zone under furnace isnt less than
+20800KPa,-8700KPa, upper pressure capacity isnt less than 8700KPa.
Tube below rear wall is loosed, thereinto 84 pieces of tube form fluidization bed
air distributor at furnace bottom, air distributor incline is 2, another 82 pieces of
tube enter into rear wall below header. Wearing layer of air distributor level is 8200,
the pitch of water wall tube at air distributor is 177.8mm, arrange 1150 bell-type
nozzle in flat steel between water wall tube, nozzle pitch is 355.6mm and arrange in
alternation. Nozzle adopt heat-resistant and wearing stainless steel cast, can operate at
1100, has high service life.
Front and rear water wall form cone at the angle of 75 degree apart in
direction of front and rear, form combustion space emulsion zone. Open any special
hole needed by CFB boiler at below water wall in this zone, include 6 coal injection at
front wall (6 limestone injection, use one hole as coal feed) , 2 start burner for left
side wall as same as right side wall, 2 seal pot material return hole at rear wall, 1
access door for overhauling at right side wall, one furnace slag notch and one ash
cooling air-return porthole at right side wall as same as left wall, two layer that it is 18
secondary air injection in all are arranged at front and rear wall. At same time arrange
enough temperature, pressure and sampling measuring porthole in this zone.
Arrange water wall panel and platen superheater along width direction at furnace
7/28/2019 Boiler Mannual
42/49
upper, transverse pitch is 711.2mm and 889mm, 14 pieces of platen superheater are
arranged in medium, one pieces of water wall panel are arranged in left side as same
as right side. Cold heating surface of platen superheater is composed of 38 pieces of
tube which diameter is44.55, material is SA213-T12, longitudinal pitch is
60.3mm, aggregately arrange 7 pieces. Hot heat surface of platen superheater is
composed of 38 pieces of tube which diameter is44.55.5, material is SA213-T23,
longitudinal pitch is 60.3mm, aggregately arrange 7 pieces. Every piece of water wall
panel is composed of 28 pieces of tube which diameter is63.56.5, material is
SA-210C, longitudinal pitch is 88.9mm.
Front wall turn to furnace rear and form furnace roof. Steam and water mixture
come from front wall and rear wall whole enter into rear water wall upper header.
Flue gas discharge from two ring headers arranged at rear wall upper, enter into
cyclone.
For wearing, spud which diameter is1025 welded at cone under furnace
bottom, water panel and its bottom, rear part of furnace roof and some area of furnace
outlet. The pitch between upper and down row spud is 30mm, angle staggers 15
degree; wearing layer thickness is around 60mm (water wall centerline). Butt-welding
bead at gas side of water wall tube above wearing layer shall be worn flat, welding
bead remnants height shall be not less than 1mm.
3.3. Back pass heating surface
Back pass heating surface includes high temperature superheater, enclosure
superheater, economizer, hanger tube and tubular air preheater. The back pass upper
part is divided into front and rear gas duct by division wall enclosure superheater.
Front gas duct has reheater insidewhile rear gas duct has high temperature
superheater and second grade economizer in sequence inside.
The cross-section of back-end convection ductwork is 12243.8width 6400.8
depth.The pipes used for front and rear enclosure wall are of 45 5 tube.
The enclosure division wall adopt 516 tube, with pitch equal for 114.3mm,
membrane wall type structure. Both front and rear enclosure wall has 107 tubes; both
left and right enclosure side wall have 57 tubes; enclosure division wall have 108
7/28/2019 Boiler Mannual
43/49
tubes. The upper part of enclosure front wall has 2 annular headers, which connect to
cyclone separator flue gas duct outlet, and thus form the flue gas duct inlet. All the
headers at enclosure wall are 273 36.
High temperature superheater tube bundle adopts in-line arrangementthe two
ends of heating surface piping are rested upon enclosure division wall and enclosure
rear wall. The welding between supporting devices and enclosure tubes is to be
performed in the shop. The specification of high temperature superheater is 51
5.5mm tubes, double tubing loop tube coil bundles, with pipe transverse pitch for
114.3mmlongitudinal pitch for 102mmtransverse direction row number 106
portrait direction row number 72low temperature segment material SA213-T22
medium temperature segment material SA213-T22high temperature segment
material SA213 - T91. In order to ensure site welding are carried out to the same class
steel, a SA335-T91 tube with length of about 100mm is to be connected to the SA213
- T91 tube, which belongs to high temperature superheater outlet segment and is
outside the flue gas duct. The specification of high temperature superheater inlet
header is 324 55, material SA335-P12while outlet header specification is 324
40, material SA335-T91.The specification of the primary desuperheater header is
32428mmmaterial SA335-P12the secondary desuperheater Header specification
is 324 28, material SA335-P12.
All the reheater tube bundles are of in-line arrangementadopting superheater
hanger tube hanging mode.The reheater heating surface piping adopts 63.5 tubes,
twosome tubing loop tube coils, pipe transverse pitch for 114.3mm, longitudinal pitch
for 114mmtransverse direction row number 106, portrait direction row number 72
altogether 4 tube groupsand materials of them are SA210A1SA213-T12SA213-T2
and SA213-T91. In order to ensure site welding are carried out to the same class steel, a
SA335-P22 tube with length of about 100mm is to be connected to the SA213 - T91
tube, which belongs to reheater outlet section and is outside the flue gas duct. The
specification of reheater inlet header is 426 16, material SA-106B; The
specification of reheater outlet header is 45735, material SA335-P22
Feedwater is lead into primary economizer inlet header from one side of the
7/28/2019 Boiler Mannual
44/49
boiler by 273 25 feed water pipes. The specification of the primary economizer
pipes is 51 5mmmaterial SA210A1with pipe transverse pitch for 90mm
transverse direction row number 70longitudinal pitch for 102mmportrait row
number 52arranged into 2 groups. And then feedwater is lead into second stage
economizer through a 273 25 connecting pipe. The specification of the
secondary economizer pipe is 515material SA210A1, pipe transverse pitch for
114.3mmtransverse direction row number 106longitudinal pitch for 102mm
portrait row number 48arranged into 2 groups. Finallyfeedwater leaving from the
second stage economizer is to be lead into the drum, through 2 219 20
connecting pipes and 12 108 10 branch pipes.
The air preheater is arranged in the back pass. Because the blast pressures of the
primary and secondary air are greatly differentthe channel boxe is divided into 2
independent air ductprimary air channel box is located at the right side of the boiler
while secondary air channel box is located at the left side of the boiler. Both of them
have 3 layers of channel boxes, with tube bundle of horizontal in-line arrangement.
The entire load of air preheater is laid upon a layer of boiler frame transverse beam.
Both Primary and Secondary air air preheater are three-pass, of in-line arrangement
transverse pitch for 75mmlongitudinal pitch for 75mmprimary air air preheater
transverse direction row number for 104secondary air air preheater transverse
direction row number for 72.
3.4 Cyclone separator and return device
See the 573-1-8609
3.5 Ash cooler
See the documents of provider
3.6. Boiler framework as well as platforms and stairways
Boiler framework is full-steel structure, a pair-column type, and the boiler roof
has light steel boiler house cover. The distance of boiler framework column from G to
K row is 37200mmwith main span width for 21000mmboth left and right sub-span
width for 5000mm, 5 layer of rigid platforms arranged in the vertical direction, the
7/28/2019 Boiler Mannual
45/49
elevation of them are EL.9000EL.21200EL.33200EL.45200 and EL.52700,
ensuring the stability of the whole boiler framework. Besides bearing the load of
boiler proper, the boiler framework can also bear the loads of the Pipes for steam and
water, gas, air, coal, oil and limestone, and also loads of soot-blowing equipment,
light boiler house roof cover, anti-wear and heat insulating materials, as well as some
load brought by the elevator (including wind force, earthquake force).
Boiler framework is designed for operation at ZoneIS-1893Part 1area,
and the basic wind press 50m/smain components are connected by the friction-type
torsion shear type high-strength boltnormal components are connected by welding.
The design of the platform, footpath and staircase has enough strength and hardness.
The live load of the platform is 10kPa (excluding the platform deadweight); the live
load of the maintenance platform is 4kPa; the live load of the other platforms is
2.5kPa; the live load of the staircase is 2kPa. Boiler operation floor is designed at
elevation 9m, Adopting checkered steel platformdrum water control chamber
platform is laid with checkered stee; plate, and the other passage platform adopts
zincification grid plates.
3.7. Hangers and supports for pressure parts
Except the primary economizer is laid upon the support beam of boiler
structure , the other pressure parts are supported by the boiler roof steel frame through
hangers and supports. In order to decrease the bending press born by the hanger rod
root during boiler operation, each heating surface lifting point is to preset offset in
every expansion direction according to different expansion capacity.
Because the drum has great load and large vertical height, U type hanger rod is
used to install the drum. 2 hanger rods are arranged at both side of the drum. The
expansion capacity during drum hot-condition operation has been taken into
consideration to decide the distance between centers of installation location in cold
condition. The hanger rod upper end is laid upon the support beam of the drum by
screw nut. During installation, for the purpose of adjusting the drum's height,
hydraulic jacks are placed at both ends of the supporting beam. Waterwalls front wall
is hung upon the boiler roof steel structure by rigid hanger and lifting eye, which are
7/28/2019 Boiler Mannual
46/49
welded to the pipe. While all the other 3 walls and waterall panel are hung upon the
boiler roof steel structure by rigid hanger on the header.
High coronet sealed supporting structure is used to hang the platen superheater.
This structure can be seen in 502573 - E1 01 furnace and down comer arrangement
drawing, as well as 502573 - E1 - 04 boiler roof lifting point and piping arrangement
drawing. The load of curtain panel are laid upon The middle transition beam through
small hanger rod, every 7 curtain panels' transition beams form the frame structure
altogether 4 transition beam frame structurethen they are hung to the boiler roof steel
structure by spring hangerensuring this hanger always on strained condition during
boiler hot-condition operation. One end of high temperature superheater tube group
and second stage economizer tube group is laid upon the enclosure rear wall, while
the other end is laid upon the division wall. The high temperature superheater
inlet/outlet header is laid upon the enclosure rear wallaround back pass enclosure
wall and division wall are hung to the boiler roof steel structure by rigid hanger.
Each row of pendant tube hang 2 reheater tube-row. Both pendant tube and
reheater tube-row are assembled by corrugated plate and tightening in the shop. The
load of the whole reheater tube group is hung to the boiler roof steel structure through
the rigid hanger and the lifting eye at upper part bend of the pendant tube. The
reheater inlet/outlet header is laid upon the enclosure front wall.
4. Others
4.1. Anti-wear measures
Because the boiler adopts circulating fluidized burning mode, plentiful circulation
materials are existed in the firing system. Furthermore, the material circulating ratio
attains 30. Therefore the anti-wear measures for firing system and tail heating surface
are of great importance.
To select furnace cross-sectional area per flue gas volume generated by firing,
and to control the flue gas velocity within the prescribed range of performance
standard, can greatly decrease the wearing at furnace heating surface. In the back pass
convection gas duct, Although the ash content in the gas is low, the rigidity of the gas
7/28/2019 Boiler Mannual
47/49
increases as the gas temperature decrease, so to choose a suitable gas velocity is a
good way to wearing on convection surface.
Furnace air distributors are poured over by about 200mm thick antifriction
pouring material. The waterwall pipes at the furnace cone segment are welded by pin
bolt, and laid with 70mm thick distance to the center of the pipe high temperature
fireproof anti-wear layer. At the transition part between cone segment and vertical
segment, Waterwall pipe are bended towards outside the boiler, ensuring the falling
material within the furnace can fall over the anti-wear layer. In addition, The weld
seam of the gas side pipes above the anti-wear layer shall be grinded smooth, and the
residual height of weld seam shall be no more than 1mm.
For both platen superheater and waterwall panel at the upper furnacethe pipes at
the lower part surface and wall-penetrating area are welded by the pin bolt, and laid
with 70 mm thick (distance to the centerline of the pipe) high temperature fireproof
anti-wear layer to prevent pipe form wearing by the ascending gas.
At furnace upper rear wall gas outlet, 70mm thick, 1000mm wide annular high
temperature fireproof anti-wear layer are laid upon the waterwall pipe surface, to
prevent the wearing to these pipes as changing gas flow.
The inner wall of cyclone separator inlet gas duct,cyclone separator and cyclone
separator outlet gas duct adopts anti-wear castable material, and is fixed by high
density pin bolt, guaranting anti-wear material firm and reliable. When laying the
114mm thick high temperature anti-wear layerthe surface of the anti-wear layer shall
be flat, and transition shall be smooth. The center pot of the separator adopts high
temperature high strength anti-wear austenitic stainless steel.
Within the U type material return leg, FBAC and its connecting pipeline, all the
internal surfaces of gas duct, which contact with high temperature high concentration
ash particles, shall be laid with a layer of high temperature anti-wear pouring material
and a layer of fireproof insulation pouring material, and fixed by Y type pin bolt.
For the heating surface of tail convection gas duct such as high temperature
superheater, reheater, economizer and air preheater, anti-wear cover shall be added to
the first row of pipe windward at flue gas inlet, to prevent pipe from abrading.
7/28/2019 Boiler Mannual
48/49
Both the ingredient and performance index of the anti-wear refractory material
shall meet the requirements raised by Shanghai Boiler Works, Ltd, details refer to
.
4.2. Sealing
CFB's furnace pressure is barotropic during operationand the operation pressure
at the lower furnace dense-phase region can reach about 10kPa. Through excellent
sealing design, SBWL can prevent gas leakage and ash leakage, and therefore provide
a clean and easeful work environment for the boiler user.
The boiler has 3 expansion centers, namely, in furnace, in cyclone separator and
in back pass. Among them, 3 layers of expansion center are designed on boiler
waterwall (elevation for EL.16700, EL.32500 and EL.41500), a layers of expansion
center is designedon on cyclone separator EL.33200, 3 layers of expansion center is
designed on back pass enclosure wall (elevation for EL.33800, EL.40800 and EL.
47200 ). This design can boiler heating parts can freely expand in order in a certian
direction during operation. Every sealing structure has determinate expansion
direction and capacity, which can provide definite reference value and reliable basis
for the sealing design.
The furnace adopts the membrane wall structure, which is formed by welding
bare tube and flat iron together. This membrane wall structure have good airtightness,
and can be laid with light refractory furnace wall to decrease boiler deadweight.
Boiler roof pipes are formed by the bending of front wall waterwall, so their
expansion is the same as of the about waterwall. This enable boiler roof sealing
design to be simplethe boiler roof pipe can be seal welded with the 2 sides
waterwalls. Upper furnace has wide pitch waterwall and platen superheater, whose
Transverse pitch are larger than 600mm. Therefore this is easy for site welding and
can guarantee the installation quality. Waterwall panel and boiler roof pipe directly
adopt comb type steel plate welding, And the platen superheater adopts metal
expansion joint for sealing, which can absorb the expansion difference between platen
superheater and waterwall. At the lower header tube seat of waterwall, sealing box is
used for sealing, while At the tube seat of annular header, flanged plate is used for
7/28/2019 Boiler Mannual
49/49
sealing. Waterwall has Positive pressure manhole door . The inner surface of manhole
door is laid with refractory material and thermal insulating material, which can
effectively prevent flue gas leakage raised by heating distortion.
At the connecting points between furnace and cyclone separator inlet gas duct,
between cyclone separator and inlet gas duct, between cyclone separator and outlet
gas duct, between cyclone separator and material return device, between cyclone
separator outlet gas duct and back pass, and between back pass and air preheater inlet,
metal/non-metal expansion joints are placed to absorb heat displacement. The
expansion joint itself is anti-wear and high temperature resistant. Compression
amount of the expansion joint shall reserve suitable allowance, in order to guarantee
certain service life.
The around enclosure wall of back pass adopts the membrane type wall structure,
which are formed by welding between bare tube and flat iron. Because all the
enclosure walls are steam cooling type, all the expansion values are the same, so the
sealing design can be simplified. The connecting points between back pass boiler roof
pipe and enclosure front wall/rear wall has no header, but pipes for direct connection.
This guarantees the sealing in structure. Boiler roof pipe are directly welded to the
enclosure sidewall, without any expansion joint. The tube seats of enclosure front
wall annular header adopts flanged plate for sealing. Sealing box is used at high
temperature superheater inlet/outlet, reheater inlet/outlet, and pipe penetrating area
between enclosure front wall and enclosure rear wall. The sealing box has metal
expansion joints at its upper and lower parts, which can absorb the heat displacement
in width direction.