Natural gas burner control system and safety issues part 2

5. Flameout protection measures馃敟

During the combustion process of the burner, if it is accidentally extinguished, the burner will enter the protection state. Because the stove is very hot. Gas can easily ignite, so it is necessary to enter a protective state and cut off the gas supply within a very short time. The response time of this process from flameout to the burner entering the protection state should not exceed 1 second.

6.Gas pressure limit protection馃敟

Gas burners have stable combustion within a certain range and only allow gas pressure to fluctuate within a certain range. The purpose of limiting the high and low pressure of gas is to ensure the stability of the flame: no flameout, no flameout, no backfire, and to limit the output thermal power of the burner to ensure safe and economical operation of the equipment. When the gas pressure exceeds this range, the burner should be locked.

The design of the burner generally uses a gas pressure switch to sense the pressure signal and output the switch signal to control the corresponding operation of the burner.

7. Insufficient pressure protection馃敟

The gas burner is designed with high thermal intensity and the combustion method is forced air explosion. If the fan fails and the air is interrupted or insufficient, the gas should be cut off immediately, otherwise the stove will stall or backfire the fan. Therefore, while improving the quality of the fan, the gas control must be interlocked with the air pressure. When the pressure is insufficient, the air source should be cut off immediately.

Generally, gas pressure switches are used to sense pressure signals and output switching signals to control the corresponding operations of gas solenoid valves.

8.Power failure protection馃敟

When the burner is suddenly cut off during operation, the gas supply must be cut off immediately to protect the safety of the equipment. The gas control solenoid valve must be normally closed. In the event of a power outage, it will automatically shut down and cut off the gas supply. The solenoid valve closing response time is less than 5S.

9. Measures to prevent gas leakage accidents馃敟

Gas leakage includes two aspects. One is that the gas leaks into the environment through the pipeline, and the other is that the gas leaks into the furnace through the end of the solenoid valve core.

Environmental leakage may lead to poisoning and explosion accidents at construction sites, and must be taken seriously. First, make sure your pipes are sealed and check them regularly for leaks. Can be used if a pipe leak must be eliminated. Secondly, in order to avoid gas concentrations that may cause poisoning and explosion, the work site is required to be well ventilated: permanent vents and forced ventilation devices; in addition, it is required to prohibit the use of fireworks, firecrackers and explosion-proof electrical components at the work site.

10.  Conclusion

A leak in the furnace may cause an explosion. There are three ways to solve the problem of air leakage in the furnace: one is to strengthen the pre-blowing time and air blowing volume to blow or dilute the gas in the furnace; the other is to use two solenoid valves in series to improve the safety of the system; the third is to use the gas before ignition The pipeline leakage detection device detects gas pipelines. If gas leakage reaches a certain amount, the burner will be locked. Measures to prevent gas leakage are external controls and are generally not included in the burner control.