The safety protection functions that the burner should have at least include:
(1) Before the burner is started, the following safety interlocks must be met, otherwise it cannot be started: ① Burner installation position verification (such as hinge switch):
② Boiler parameters (pressure, temperature, etc.) are normal:
③ Boiler water level is normal.
(2) During normal operation of the burner, the safety interlock point before starting should continue to maintain the verification state, and the following control parameters and safety control functions should remain normal, otherwise the system should stop running, issue an alarm or implement interlock protection:
① Flame monitoring;
② Combustion air verification;
Fuel pressure verification:
4 Fuel preheating temperature verification:
Fuel and air ignition position verification;
⑥ Gas valve leak detection;
⑦ Atomizing medium pressure verification:
⑧ Instrument air pressure verification:
⑨ Rotor speed verification:
⑩ Power failure.
(3) Furnace purge
To avoid the presence of combustible mixed gas in the furnace or flue before the burner is ignited, both oil and gas burners must be pre-purged before ignition to ensure ignition safety. Gas burners should be post-purged after controlled shutdown. The purge time (or purge air volume) is clearly specified in relevant national standards or industry standards.
(4) Safety time
The time limits of several key nodes in the start-up operation of the burner are set in the burner logic control.
① Ignition safety time refers to the maximum time that the ignition fuel valve is allowed to remain open if the flame detector does not detect the ignition flame during the ignition process to control the amount of ignition gas entering the furnace.
② Main fire safety time refers to the maximum time that the main fuel valve is allowed to remain open if the flame detector does not detect the main flame when the main flame is ignited to control the amount of main gas entering the furnace.
③ Flameout safety time refers to the maximum time interval from the moment the flame is extinguished to the moment the fuel valve begins to close.
The setting values of safety time of different types of burners shall comply with the provisions of relevant standards.
(5) Starting thermal power
Limiting the thermal power of the burner during ignition startup to ensure the safety and reliability of the ignition process is a very necessary safety measure. Excessive starting power is one of the common direct causes of deflagration or explosion accidents in actual projects.
The starting thermal power of various types of burners shall comply with the provisions of relevant standards.
(6) Restarting
The relevant provisions for restarting the burner after a failed start-up are as follows:
① Failure during pre-purge. For burners with a rated power of less than or equal to 120kW, it is allowed to restart once after safe shutdown. If the restart fails, it should be shut down and interlocked.
② Flame failure during ignition. For forced draft burners, it can be restarted up to 2 times according to the operating procedure. If the restart fails, it should be safely shut down and interlocked.
③ Flame failure during operation. For fuel burners with a rated power of less than or equal to 400kW (except alcohol-based fuel), it is allowed to restart once according to the procedure after safe shutdown. If the restart fails, it should be safely shut down and interlocked.
(7) Electrical safety
The electrical control equipment of the burner shall comply with the corresponding electrical safety standards.
① The electrical equipment shall have sufficient insulation resistance, dielectric strength, heat resistance, moisture resistance, flame retardancy and other properties, and shall be reliably grounded.
② The electrical equipment shall have sufficient mechanical strength, good casing protection and stability.
The safety protection functions that the burner should have at least include:
(1) Before the burner is started, the following safety interlocks must be met, otherwise it cannot be started: ① Burner installation position verification (such as hinge switch):
② Boiler parameters (pressure, temperature, etc.) are normal:
③ Boiler water level is normal.
(2) During normal operation of the burner, the safety interlock point before starting should continue to maintain the verification state, and the following control parameters and safety control functions should remain normal, otherwise the system should stop running, issue an alarm or implement interlock protection:
① Flame monitoring;
② Combustion air verification;
Fuel pressure verification:
4 Fuel preheating temperature verification:
Fuel and air ignition position verification;
⑥ Gas valve leak detection;
⑦ Atomizing medium pressure verification:
⑧ Instrument air pressure verification:
⑨ Rotor speed verification:
⑩ Power failure.
(3) Furnace purge
To avoid the presence of combustible mixed gas in the furnace or flue before the burner is ignited, both oil and gas burners must be pre-purged before ignition to ensure ignition safety. Gas burners should be post-purged after controlled shutdown. The purge time (or purge air volume) is clearly specified in relevant national standards or industry standards.
(4) Safety time
The time limits of several key nodes in the start-up operation of the burner are set in the burner logic control.
① Ignition safety time refers to the maximum time that the ignition fuel valve is allowed to remain open if the flame detector does not detect the ignition flame during the ignition process to control the amount of ignition gas entering the furnace.
② Main fire safety time refers to the maximum time that the main fuel valve is allowed to remain open if the flame detector does not detect the main flame when the main flame is ignited to control the amount of main gas entering the furnace.
③ Flameout safety time refers to the maximum time interval from the moment the flame is extinguished to the moment the fuel valve begins to close.
The setting values of safety time of different types of burners shall comply with the provisions of relevant standards.
(5) Starting thermal power
Limiting the thermal power of the burner during ignition startup to ensure the safety and reliability of the ignition process is a very necessary safety measure. Excessive starting power is one of the common direct causes of deflagration or explosion accidents in actual projects.
The starting thermal power of various types of burners shall comply with the provisions of relevant standards.
(6) Restarting
The relevant provisions for restarting the burner after a failed start-up are as follows:
① Failure during pre-purge. For burners with a rated power of less than or equal to 120kW, it is allowed to restart once after safe shutdown. If the restart fails, it should be shut down and interlocked.
② Flame failure during ignition. For forced draft burners, it can be restarted up to 2 times according to the operating procedure. If the restart fails, it should be safely shut down and interlocked.
③ Flame failure during operation. For fuel burners with a rated power of less than or equal to 400kW (except alcohol-based fuel), it is allowed to restart once according to the procedure after safe shutdown. If the restart fails, it should be safely shut down and interlocked.
(7) Electrical safety
The electrical control equipment of the burner shall comply with the corresponding electrical safety standards.
① The electrical equipment shall have sufficient insulation resistance, dielectric strength, heat resistance, moisture resistance, flame retardancy and other properties, and shall be reliably grounded.
② The electrical equipment shall have sufficient mechanical strength, good casing protection and stability.