GB/T 16508.6-2022 English PDF (GBT16508.6-2022)
GB/T 16508.6-2022 English PDF (GBT16508.6-2022)
GB/T 16508.6-2022: Shell boilers - Part 6???Combustion systems
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
CCS J 98
Replacing GB/T 16508.6-2013
Shell boilers - Part 6: Combustion systems
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 ... 9
4 Combustion systems for liquid and gaseous fuels ... 10
5 Layered combustion systems for solid fuels ... 15
Bibliography ... 18
Shell boilers - Part 6: Combustion systems
This document specifies the technical requirements for shell boiler combustion systems. This document is applicable to the shell boiler combustion systems defined in GB/T 16508.1, including:
a) Fuel inlet pipelines for liquid and gas fuel boilers, air supply and induction systems, combustion equipment as well as all related control and monitoring equipment;
b) Material supply (such as coal, biomass briquette fuel, etc.) system, air supply and induction system, combustion equipment, ash removal (slag) device and all related control and monitoring equipment of solid fuel layer-fired boilers. This document does not apply to combustion systems that use pulverized coal and coal- water slurry as fuel.
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 2900.48, Electrotechnical terminology of boilers
GB 11174, Liquefied petroleum gases
GB/T 13612, Manufactured gas
GB/T 16508.1, Shell boilers - Part 1: General requirements
GB/T 16508.5, Shell boilers - Part 5: Safety appurtenances and instruments GB 17820, Natural gas
GB/T 18342, Commercial coal quality - Coal for travelling grate boiler
GB/T 24146, Rubber hoses and hose assemblies for use in oil burners - Specification GB 25989, Fuel oils for burners
GB/T 36699, Specification for liquid fuels and gaseous fuels burners of boilers GB/T 38753, Liquefied natural gas
GB 50041, Standard for design of boiler plant
JB/T 3271, Specification for travelling grate stokers
NB/T 47034, Technical conditions of industrial boilers
NB/T 47050, Technical specification for reciprocating grate
NB/T 47062, Biomass molded fuel fired 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 liquid fuel
Natural organic fuels that are liquid at normal temperature and pressure as well as their processed liquid fuels, including light oil, heavy oil, and biomass oil. 3.2 gaseous fuel
Natural organic fuels or artificial fuels that are gaseous at normal temperature and pressure, including natural gas, liquefied petroleum gas, coke oven gas, mixed city gas, blast furnace gas, converter gas, combustible industrial tail gas, hydrogen and biogas, etc.
3.3 solid fuel
Solid fossil fuels, biomass fuels and processed fuels, including various qualities of coal (bituminous coal, anthracite, lignite, etc.), biomass solid fuels, combustible solid waste, etc.
3.4 flame detector
A device that detects the presence or absence of a flame and sends a signal to the control device.
NOTE: It generally consists of a sensing device and a switching device. 3.5 ignition device
A device for igniting fuel in the ignition burner or main burner.
4 Combustion systems for liquid and gaseous fuels
4.1 Fuel and burner selection
4.1.1 Natural gas shall meet the requirements of GB 17820. Liquefied natural gas, liquefied petroleum gas and artificial gas shall meet the requirements of GB/T 38753, GB/T 11174, and GB/T 13612, respectively.
4.1.2 Under the premise of not affecting the safe operation of the burner, the liquid fuel shall reach the viscosity required for its normal combustion at the burner inlet. Fuel oil shall meet the requirements of GB 25989.
4.1.3 Each boiler shall be equipped with an accumulative instrument for fuel quantity. It can be configured during boiler room design.
4.1.4 When designing or selecting a burner, factors such as boiler structure and parameters, fuel characteristics, flue gas resistance, excess air coefficient, and pollutant emissions shall be considered. They shall adapt to boiler load changes, use environment, etc.
4.1.5 The burner equipped with the boiler shall meet the requirements of GB/T 36699. Meet the following requirements when selecting:
a) The actual output power of the burner shall be greater than or equal to the boiler thermal power divided by the boiler thermal efficiency.
b) The flame diameter and length of the burner shall match the furnace chamber size of the boiler.
4.1.6 When the burner leaves the factory as an independent product, the accompanying documents shall at least include the following:
a) Drawings of product appearance and installation dimensions;
b) Electrical wiring diagram;
c) Product instruction manual;
d) Product certificate of conformity;
e) Product type test certificate or inspection spot check certificate (copy); f) Product packing list.
4.1.7 The product instruction manual of the burner shall at least include the following contents:
c) After the gas pipeline is installed, it shall use air or inert gas to carry out air tightness test and strength test at 1.5 times the design pressure and not less than 4 kPa. The test pressure shall not exceed the maximum allowable operating pressure of the valve.
d) Safety cut-off valves and pressure relief valves shall be installed on the gas pipeline.
e) A filter device shall be installed at the inlet of the gas control valve. The filter device can be integrated with downstream gas control valve. The pore size of the filter shall not be larger than 1.5 mm. Permanent pressure measuring points shall be set at the inlet and outlet of the filter.
f) The upstream of all automatic control valves in the main gas control valve system shall be equipped with manual quick cut-off valves. The cut-off valve shall be set in a safe and easy-to-operate place.
g) A relief valve shall be installed on the gas main line in front of the gas boiler. The outlet of its emptying pipe shall lead directly to the outside.
h) The design and layout of the gas pipeline shall meet the requirements of corrosion resistance, explosion protection and thermal expansion in its working
4.3 Air supply and induction systems
4.3.1 Air supply system
22.214.171.124 When multiple burners share one blower, a pressure measuring device shall be installed in front of each burner on the air supply pipeline.
126.96.36.199 When the air required for combustion is provided by a shared blower, a cut-off device (such as a baffle) shall be provided on the air duct of each burner. The following requirements shall be met:
a) The opening and closing positions of the cut-off device shall be clearly indicated. b) When the fuel supply to the burner is cut off, the air supply shall be cut off according to the procedure.
4.3.2 Air induction system
188.8.131.52 The exhaust gas temperature of each boiler shall be monitored. For steam boilers with a rated evaporation capacity not less than 20 t/h or hot water boilers with a rated thermal power not less than 14 MW, the oxygen content in the exhaust gas shall be monitored. If the system has an induced fan, the opening or frequency of the induced fan shall be monitored.
184.108.40.206 Under the premise of ensuring that no flammable and explosive mixtures are produced, the exhaust ducts of multiple boilers can share one chimney. The smoke exhaust shall be guaranteed to be smooth. Baffles and limit devices shall be installed in the branch flue of each boiler. When the boiler is running, the baffle shall be fully open. 220.127.116.11 When setting up the flue gas recirculation system, the flue gas and air shall be mixed evenly. Take effective measures to prevent moisture condensation in the mixed gas from affecting normal combustion.
18.104.22.168 When the flue gas is corrosive, effective anti-corrosion measures shall be taken for the flue.
4.4 Combustion system safety and control
4.4.1 The burner shall be equipped with ignition device, automatic controller, safety cut-off valve, flame detector, air pressure monitoring device, fuel pressure monitoring device and other safety protection devices.
4.4.2 The configuration of the automatic safety cut-off valve of the burner shall comply with the provisions of GB/T 36699. For rotor cup atomized liquid fuel burners and medium atomized liquid fuel burners, the selection and arrangement of safety cut-off valves can refer to the requirements of pressure atomized burners.
4.4.3 During the start-up process of the burner with a preheating device, before reaching the minimum preheating temperature of the liquid fuel, the normally open safety shutdown device shall not cut off the fuel supply.
4.4.4 The arrangement and installation of the flame detector shall comply with the requirements of GB/T 36699. When the boiler has multiple burners, the setting of the furnace flame detector shall be able to accurately monitor the combustion status of the furnace.
4.4.5 Before the burner starts to ignite, the combustion chamber and flue shall be pre- purged. The purging time and air volume shall meet the requirements of GB/T 36699, etc.
4.4.6 The burner's ignition and flameout safety time, starting thermal power and restarting shall comply with the provisions of GB/T 36699.
4.4.7 The burner shall be able to automatically control the combustion for safe operation. When the following abnormalities occur during startup and operation, the burner shall be able to cut off the fuel supply within a safe time, stop it safely and interlock for protection:
a) When the interlock protection is triggered under the following conditions, it can only be restarted through manual intervention:
4.4.11 During the closing process of the gas burner and before the gas control valve system is closed, the air supply system shall not be automatically closed. 4.4.12 When the power supply is interrupted during the start-up and operation of the burner, the burner shall be able to shut down safely.
4.4.13 The high-voltage ignition device shall have obvious warning signs. 4.4.14 The inspection hole opened on the combustion chamber shall be firm and sealed. 4.4.15 For steam boilers with a rated evaporation greater than 20 t/h or hot water boilers with a rated thermal power greater than 14 MW, recording instruments for fuel temperature and pressure shall be installed.
4.4.16 After the boiler installation is completed, the burner commissioning shall be carried out according to the following requirements:
a) Safety commissioning, including air tightness (gas burner), safety time (ignition and flameout safety time), pre-purge time, flame stability, gas pressure switch, air pressure switch, etc. When a hinge switch is configured, its interlock function shall be tested separately.
b) Operation commissioning, including the range of burner output thermal power and the test of combustion product emissions under operating conditions. 5 Layered combustion systems for solid fuels
5.1 Fuel and combustion equipment
5.1.1 The fuel of the layered boiler shall comply with the provisions of GB/T 18342, NB/T 47034, NB/T 47050, NB/T 47062 or design documents.
5.1.2 Combustion equipment shall be compatible with the boiler structure. The continuous, stable and complete combustion of the fuel is completed under the design working conditions. The chain grate shall meet the requirements of JB/T 3271. The reciprocating grate shall meet the requirements of NB/T 47050.
5.1.3 The feeding material (such as coal, biomass briquette fuel, etc.) system shall meet the requirements of GB/T 16508.5 and GB 50041.
5.1.4 Each boiler shall be equipped with an accumulative instrument for fuel quantity. It can be configured during boiler room design.
5.1.5 The chain grate shall be equipped with a grate-speed display instrument. 5.1.6 Access doors shall be installed at appropriate parts of the grate. 5.1.7 When the combustion equipment leaves the factory as an independent product, at least the following accompanying documents shall be attached:
a) Product outline and dimension drawings; installation dimension drawings required for products shipped in bulk;
b) Product instruction manual;
c) Product certificate of conformity;
d) Product packing list.
5.1.8 The instruction manual for combustion equipment products shall at least include the following:
a) Installation instructions (provided for products shipped in bulk);
b) Instructions on how to operate;
c) Maintenance instructions;
d) Measures to be taken in unusual circumstances.
5.2 Air supply and induction systems
5.2.1 Air supply system
22.214.171.124 The air duct (including the load-bearing bellows of the grate device) shall be able to withstand the mechanical loads generated during operation.
126.96.36.199 The air duct shall be sealed. When the boiler is equipped with an air preheater, the hot air passage shall also be effectively insulated.
188.8.131.52 For the combustion system equipped with primary and secondary air, the ratio of air supply shall be monitored.
184.108.40.206 Air distribution adjustment and cut-off devices shall be installed on the air supply duct.
220.127.116.11 The opening or frequency of each boiler blower shall be monitored. For steam boilers with a rated evaporation capacity not less than 20 t/h or hot water boilers with a rated thermal power not less than 14 MW, if an air preheater is installed, the outlet air temperature shall be monitored.
5.2.2 Air induction system
18.104.22.168 The exhaust gas temperature, opening degree or frequency of induced fan of each boiler shall be monitored. For steam boilers with a rated evaporation capacity not less than 20 t/h or hot water boilers with a rated thermal power not less than 14 MW,