GB/T 16508.6-2022Shell boilers - Part 6: Combustion systems (English PDF)

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.

4.3.1 Air supply system

4.3.1.1 When multiple burners share one blower, a pressure measuring device shall be installed in front of each burner on the air supply pipeline.

4.3.1.2 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

4.3.2.1 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.

4.3.2.2 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.

4.3.2.3 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.

4.3.2.4 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:

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;

5.2.1 Air supply system

5.2.1.1 The air duct (including the load-bearing bellows of the grate device) shall be able to withstand the mechanical loads generated during operation.

5.2.1.2 The air duct shall be sealed. When the boiler is equipped with an air preheater, the hot air passage shall also be effectively insulated.

5.2.1.3 For the combustion system equipped with primary and secondary air, the ratio of air supply shall be monitored.

5.2.1.4 Air distribution adjustment and cut-off devices shall be installed on the air supply duct.

5.2.1.5 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

Note 1. 2. **Search (Optional).** Enter the keyword '**GB/T 16508.6-2022**' in the search bar, if it is not already shown. 3.

Note 2. 9.

Note 3. 10. **Verification (USD

Notes and Explanations

Note 1:**[GB/T 16508.6-2022](https://

Note 3:** If you are unable to redirect back to our Return Page, do not worry. **Additionally and independently**, our automated system will still deliver your PDF and Invoice via email **(the second mechanism to ensure the delivery)**, typically within 3 minutes. Once your payment is complete, you have two instant ways to access your PDF and invoice: you may stay on the Return Page for download in 3 minutes typically, or simply check your email inbox where a copy is automatically delivered in 3 minutes typically.