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GB/T 16508.8-2022 PDF in English


GB/T 16508.8-2022 (GB/T16508.8-2022, GBT 16508.8-2022, GBT16508.8-2022)
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GB/T 16508.8-2022: PDF in English (GBT 16508.8-2022)

GB/T 16508.8-2022
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 27.060.30
CCS J 98
Replacing GB/T 16508.8-2013
Shell boilers - Part 8: Operation
ISSUED ON: JULY 11, 2022
IMPLEMENTED ON: FEBRUARY 01, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword ... 3
Introduction ... 6
1 Scope ... 8
2 Normative references ... 8
3 Terms, definitions and symbols ... 8
4 Basic requirements ... 9
5 Preparation before operation ... 11
6 Start-up ... 14
7 Operation ... 16
8 Boiler shutdown ... 19
9 Inspection and maintenance ... 20
10 Troubleshooting ... 25
Bibliography ... 30
Shell boilers - Part 8: Operation
1 Scope
This document specifies the basic requirements for the operation and management of
shell boilers, as well as the requirements for preparation before operation, start-up,
operation, shutdown, inspection and maintenance, and troubleshooting.
This document applies to shell boilers defined in GB/T 16508.1.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 1576, Water quality for industrial boilers
GB/T 2900.48, Electrotechnical terminology of boilers
GB/T 12145, Quality criterion of water and steam for power plant and steam-
generating equipment
GB 13271, Emission standard of air pollutants for boiler
GB/T 16508.1, Shell boilers - Part 1: General requirements
GB/T 34355, Steam and hot water boiler chemical cleaning regulation
GB/T 36699, Specification for liquid fuels and gaseous fuels burners of boilers
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions defined in GB/T 2900.48
and GB/T 16508.1 as well as the followings apply.
3.1 boiler dry maintenance
dry measures that are taken on the heating surface of the boiler and the metal surface of
the steam-water system when the boiler is out of service
3.2 boiler wet maintenance
rise and there is no shortage of water.
e) When any of the following situations occur during the operation of the boiler, such
as leakage of pressure components, serious coking in the boiler, inability to
discharge slag, serious ash blockage in the tail flue, red burning of the boiler wall,
serious overheating of the metal on the heating surface, serious deterioration of
the quality of steam and water, etc., the boiler shall be stopped immediately from
running.
f) When the flue gas temperature at the inlet of the waste heat boiler and the
corrosiveness of the flue gas components exceeds the design range or the inlet
flue gas is not suitable for entering the waste heat boiler, the waste heat boiler
shall be isolated and the boiler shall be stopped.
4.2.3 Boiler water quality shall meet the requirements of GB/T 1576 or GB/T 12145.
4.2.4 The emission limits of air pollutants during boiler operation shall comply with the
provisions of GB 13271 and meet the environmental protection requirements of the area
where the boiler is used.
5 Preparation before operation
5.1 Boiler exterior inspection
5.1.1 The boiler proper, auxiliary equipment as well as supports and hangers shall be in
good condition.
5.1.2 The adjustment devices and baffles of the air duct and flue shall be in good
condition. The switch is flexible. The opening and closing instructions are correct.
5.1.3 The outer boiler wall and insulation of the boiler shall be in good condition.
5.1.4 The boiler door, ash door, fire door hole, explosion-proof door, and hand holes,
head holes, manholes, inspection door holes and other devices shall be in good
condition and closed tightly.
5.1.5 The settlement and cracking of the boiler foundation shall meet the requirements.
5.2 Boiler safety appurtenance and instrument inspection
5.2.1 The safety appurtenance and instruments shall be complete, in good condition,
and in the state of being put into use.
5.2.2 The pressure gauge shall indicate correctly. The water trap shall be normal. The
three-way cock of the pressure gauge can be opened and closed flexibly.
5.2.3 The water level gauge and its accessories shall ensure that the water level
indication is clearly visible. The connection valve and drain valve of the water level
gauge shall be opened and closed flexibly.
5.2.4 The temperature measuring device shall indicate correct.
5.2.5 The lead seals of safety valves and relief valves shall be in good condition. The
relief pipe is intact and unblocked to ensure safe relief. When the ambient temperature
of the boiler may be lower than 0°C, antifreeze measures shall be taken.
5.3 Energy efficiency monitoring device, energy meter inspection
The fuel consumption device, thermometer and flow meter shall be complete and in
good condition. The indication shall be correct.
5.4 Heating surface inspection
5.4.1 The outsourcing, insulation and sealing of the heating surface shall be in good
condition. When the inspection door and hole are closed, the seal shall be good.
5.4.2 When there is any doubt about whether there is any foreign matter or dust
accumulation on the flue air side of the economizer, air preheater and superheater, it
shall be checked to ensure the smooth flow of the flue.
5.5 Steam-water piping and valve inspection
The water supply (inlet) piping, steam piping, water outlet piping, return water piping,
drain piping and sewage piping of the boiler shall be unblocked. The support and
insulation of each piping shall be good. The valves on the piping shall be intact. The
opening-closing is flexible. The opening-closing and opening degree of the valve shall
be kept in the correct position.
5.6 Combustion equipment inspection
5.6.1 Combustion equipment shall be free from deformation and damage affecting
normal operation. The test run of the mechanical transmission device is normal. The
lubrication is good.
5.6.2 The grate shall be free from deformation and damage affecting normal operation.
There is appropriate gap between grate pieces. The operation is normal.
5.6.3 Liquid and gas fuel burners shall meet the following requirements:
a) Liquid fuel burner: the appearance is normal. Ignition devices, automatic
controllers, safety cut-off valves, flame monitoring devices, air pressure
monitoring devices, fuel pressure monitoring devices, oil pumps, oil heaters, oil
pressure gauges, oil temperature gauges, cocks, valves, joints, etc. are complete
and in good condition. There is no visible deformation, breakage, clogging or
leaking. The instrument indication is correct.
meets the operating requirements.
5.13 Flue and chimney inspection
When 2 or more boilers share one flue or chimney, the drafting force of each boiler
shall be balanced. The smoke exhaust pipe of each boiler shall be provided with flue
regulating device and required explosion-proof door separately. When some boilers are
turned on, measures shall be taken to prevent the high-temperature flue gas from
flowing backward.
6 Start-up
6.1 Boiler water supply
6.1.1 Water supply of steam boiler
6.1.1.1 Water shall be supplied in when the boiler water inlet valve is open. The water
inlet speed shall be in accordance with the requirements of the boiler instruction manual.
6.1.1.2 In the process of water supply, check whether the vent valve is exhausted,
whether there is water leakage at the hole cover of the drum, the header, and the valves,
flanges, plugs of each part. When the water reaches the minimum safe water level, stop
the water for inspection. If there is any abnormal situation, it shall be dealt with.
6.1.1.3 When the boiler ignition has special requirements on the water level, the water
shall be filled to the required water level.
6.1.2 Water supply of hot water boiler
6.1.2.1 Before filling the hot water boiler, all drain valves and traps shall be closed. At
the same time, open the bypass valve connecting the water supply and return pipe at the
end of the pipe network.
6.1.2.2 Supply water until water emerges from the top of the boiler, in the pipe network,
and the vent valve on the gas collecting tank.
6.2 Ignition
6.2.1 The ignition method and procedure of the boiler shall be carried out in accordance
with the requirements of the boiler operation manual or the operating procedures
formulated by the user.
6.2.2 When the boiler has a flue adjustment device or a baffle, the flue gas passage shall
be kept unobstructed. Flammable fuels shall not be used for ignition. Before the hot
water boiler is ignited, the circulating water pump shall be started.
6.2.3 Solid fuel boiler ignition meets the following requirements:
a) When ignition equipment is provided, its safe operation shall be ensured.
b) When liquid or gaseous fuel is used for ignition, the ignition equipment shall meet
the requirements of GB/T 36699.
6.2.4 Liquid and gaseous fuel boiler ignition complies with the following requirements.
a) Before the burner starts to ignite, the combustion chamber and flue shall be pre-
purged. The pre-purge time and purge air volume meet the following
requirements:
1) The total ventilation volume before ignition shall not be less than 3 times the
total volume of the flue from the boiler to the chimney inlet.
2) When the pre-purge is performed with the combustion air flow rate under the
rated output power, the pre-purge time shall not be less than 20 s.
b) When the liquid or gas fuel boiler fails to ignite once, check whether the flame
detector is normal, whether the flameout protection works, and whether the fuel
supply is cut off after flameout. There shall be a sufficient time interval for re-
ignition. The requirements for sufficient pre-purge air volume shall be met.
6.2.5 During the ignition and start-up of solid fuel boilers, the normal delivery of fuel
shall be ensured and the following requirements shall be met.
a) When one of the following situations occurs, the delivery of fuel to the boiler shall
be stopped:
1) The grate is not functioning properly.
2) The safety control device fails.
3) The blower or induced draft fan is not working properly.
4) The slag removal equipment is not working properly.
5) Fail to meet safety ignition requirements.
6) Parameters related to boiler safety (such as water level, temperature, pressure,
etc.) exceed the limit.
b) When the reasons 1) ~ 5) are eliminated, it can be restarted directly. When the
situation 6) occurs, only manual reset shall be used to restart.
c) Boilers using auxiliary combustion systems shall be operated in accordance with
the boiler operating instructions of the manufacturer.
d) When the ignition device is configured, the ignition device shall keep running
The steam pressure shall be kept stable during the operation of the boiler. It shall not be
run at over-pressure. The steam pressure adjustment of the boiler can be realized by
adjusting the combustion and other methods, so as to ensure that the boiler evaporation
meets the requirements of the steam supply load.
7.2 Water level adjustment
7.2.1 During operation, the water level gauge shall be kept intact, with correct
indication, clear visibility and sufficient lighting.
7.2.2 Boiler water supply shall maintain the boiler water level within the normal range
of the drum water level gauge. The boiler water supply shall be adjusted according to
the indication of the drum water level gauge. The deviation of the water level gauge
shall comply with the requirements of the boiler instruction manual. When there is an
abnormality in the water level gauge, it shall be dealt with in time.
7.2.3 When the boiler load changes greatly, attention shall be paid to the "false" change
of the water level to avoid mis-operation.
7.2.4 When the water supply automatic regulator is put into operation, the change of
the drum water level shall be monitored. Check whether the feed water flow is
consistent with the steam flow.
7.3 Outlet water temperature adjustment of hot water boiler
7.3.1 The boiler user shall formulate the relationship curve between the boiler outlet
water temperature and the outdoor air temperature according to the local conditions.
During operation, the combustion adjustment is carried out in time according to the
corresponding relationship between the specified outlet water temperature and the
outdoor air temperature.
7.3.2 The outlet water temperature of the hot water boiler shall be lower than the
corresponding saturation temperature (that is, the vaporization temperature of the boiler
water) under the operating pressure by 30°C.
7.4 Combustion adjustment
7.4.1 Boiler operators shall monitor boiler operating parameters. When the
requirements cannot be met, the operating parameters of the boiler and the heating
system shall be adjusted in time.
7.4.2 According to the requirements of the boiler operation manual, adjust the
combustion conditions according to the changes in the boiler load. The adjustment
method (such as adjusting the fuel supply, air supply, etc.) can be determined according
to the fuel type, boiler structure and combustion method of the boiler.
a) During the operation of the mechanical grate boiler, it is necessary to prevent the
overheating of the grate pieces, grate brackets and ash baffles, etc. After pressing
the fire, if there is overheating, natural ventilation can be strengthened to cool it
down. Watering to cool down is prohibited. The combustion adjustment method
is as follows:
1) During normal operation, the feeding volume and air supply volume shall be
adjusted in time according to the change of boiler load. Usually adjust the
feeding amount by changing the speed or frequency of the grate.
2) Methods such as adjusting the air volume of the blower and induced draft fan,
and the opening of the grate air distribution damper shall be adopted to reduce
the excess air coefficient at the smoke exhaust area, and the carbon content of
slag and fly ash.
b) The combustion adjustment of the oil-fired gas boiler is carried out according to
the operating instructions of the boiler and burner.
7.4.3 If one of the following situations occurs during the operation of the boiler, the air
supply and fuel delivery shall be stopped urgently:
a) Failure of combustion equipment or slag removal equipment;
b) Failure of the safety protection device;
c) The blower or induced draft fan is not working properly;
d) Control parameters related to boiler safety (such as water level, temperature,
pressure, etc.) exceed the limit;
e) Other situations that require emergency shutdown as specified in the boiler
operating instructions.
7.5 Control and interlock protection
7.5.1 The operation of the control system meets the requirements as follows:
a) The control system shall be regularly verified. The automatic control system of
boiler shall not be disconnected. The damage or failure of the control device shall
be repaired in time.
b) When the control system is put into operation, the change of boiler operating
parameters and the action of the control system shall be monitored. Avoid adverse
consequences caused by failure.
c) When the failure of the automatic control device cannot be repaired immediately,
when the operation of the boiler cannot be stopped, when the automatic control
of the disconnection confirms that it will not affect the safe operation of the boiler,
it shall be confirmed by the person in charge of the boiler equipment of the user
in the boiler needs to be drained, it shall be done when the water temperature inside the
boiler is lower than 70°C.
8.2.3 During emergency shutdown, if there is no water shortage or full water
phenomenon, water supply and sewage discharge can be used to accelerate cooling and
reduce boiler pressure.
8.2.4 After the emergency shutdown, the residual heat in the boiler shall be dissipated
urgently. For the grate boiler, it can be handled according to the nature of the fault. It
can also clean out the fuel in the boiler. But under no circumstances shall water be
poured into the boiler to cool the boiler.
8.2.5 For emergency shutdown of hot water boilers, the circulating water pump shall
not be stopped immediately. The circulating water pump can only be stopped when the
boiler outlet water temperature drops below 50°C. Close the outlet valve. Open the
relief pipe. Let off the steam. If the vaporization continues, water can be fed into the
boiler, and water can be released from the discharge pipe, so as to make the boiler water
flow and reduce the temperature of the boiler water. If there is a natural circulation loop
between the hot water boiler and the hot water heating system, the valve on the natural
circulation loop shall be opened.
8.3 Power failure protection
8.3.1 Boiler users shall formulate protective measures to prevent boiler water from
vaporizing in case of sudden power failure according to the structural characteristics of
the boiler.
8.3.2 If the liquid and gas fuel boiler suddenly lose power during operation, the power
switch of the burner shall be disconnected. The liquid and gas fuel supply valve shall
be closed.
9 Inspection and maintenance
9.1 Basic requirements
9.1.1 The user shall formulate the maintenance system and operation method in line
with the actual situation of the unit according to the boiler operation manual.
9.1.2 The user shall arrange the shutdown of the boiler in a planned way. Carry out
comprehensive and restorative maintenance on the boiler equipment or replacement of
parts and components. Boiler shutdown maintenance shall be carried out every three
months. During the operation of the boiler, the boiler shall not be shut down for partial
or preventive maintenance.
9.1.3 In-service boilers shall be inspected at least once a month. The inspection shall at
least include the following items:
a) Boiler pressure-bearing components;
b) Safety appurtenance and instruments, interlock protection devices;
c) Burner piping (including valves);
d) Safety and control devices, burner operating procedures;
e) Implementation of boiler safety and energy saving management system;
f) Operator's license and validity period;
g) Periodic inspection of boilers;
h) Regular water quality assay and analysis;
i) Water seal pipe condition;
j) Other exceptions.
9.1.4 The burner equipped with the boiler shall be inspected at least once a year. The
inspection shall at least include the following items:
a) Whether the burner pipeline (including valves) is sealed;
b) Whether the safety and control devices are complete and intact; whether the safety
and control functions are missing or invalid;
c) Whether the burner is operating normally, etc.
9.2 Inspection maintenance
9.2.1 Safety appurtenance and instruments
9.2.1.1 Pressure gauge
During the operation of the boiler, when there are failures affecting safety such as
rupture, leakage, and incorrect indication pressure of the pressure gauge and the three-
way cock, it shall be repaired in time, and the boiler can also be shut down for
maintenance. The water trap and connecting pipe of the pressure gauge shall be flushed
regularly to ensure unobstructed flow. When the pressure gauge has one of the
following conditions, it shall be stopped using:
a) When there is no pressure on the pressure gauge with limited stop pin, the pointer
cannot return to the stop pin after turning. For pressure gauges without stop pins,
when there is no pressure, the value of the pointer from the zero position exceeds
the allowable error specified by the pressure gauge.
b) The surface glass is broken, or the scale of the dial is blurred.
9.2.2.2 Fans
During the normal operation of the fan, the current change of the motor, bearing
lubrication, oil level and bearing temperature shall be observed. When encountering the
following situations, stop the machine immediately for inspection or repair:
a) Smoke from the motor;
b) Strong vibration and loud collision sound;
c) Sudden increase of current value.
9.2.2.3 Dust removal, desulfurization and denitrification equipment
Inspect and maintain according to the following requirements.
a) The dust collector shall be kept sealed during operation. The ash discharge system
shall operate normally. The ash discharge shall be smooth.
1) Water film dust collector: The water level of the water tank of the dust collector
shall be kept normal. The water supply shall not be interrupted, or the tank
overflowed. The air lock shall be flexible, and the water seal shall be tight. The
water door of the dust collector shall be fully opened. Nozzle flow is smooth.
When there is clogged dust at the bottom of the dust collector, it shall be
dredged in time.
2) Bag type dust collector: Effective safety protection measures shall be taken
before the entrance, so as to ensure the normal working conditions of the dust
collector. When the flue gas temperature is too high or too low, the bag type
dust collector shall be isolated so that the flue gas enters the bypass flue. Avoid
damaging or sticking the filter bags. If it is out of service for a long time, it
shall be cleaned and run for 15 min to 30 min after stopping the work. Keep
the filter bag dry during outage.
3) Electrostatic precipitator: During operation, the changes of current and voltage
shall be observed. In case of abnormality, inspection and maintenance shall be
carried out in time.
b) For wet desulfurization equipment, it shall be regularly checked whether the
nozzle of the device is blocked, whether the concentration of desulfurizer in the
washing liquid meets the requirements. If clogging is found, it shall be dredged
in time.
c) For denitrification equipment, it is necessary to regularly check whether the nozzle
of the device is blocked, whether the concentration of denitrification agent meets
the requirements, whether the catalyst is invalid, and whether the system is
leaking. If problems are found, they shall be resolved in time.
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.