First of all, don't panic. According to the normal shutdown sequence, check whether the fuel, steam and water valves of gas-fired boiler meet the shutdown requirements.
Secondly, close the surface blowdown valve of the gas-fired boiler to prevent other faults of the boiler. Then, quickly close the main steam valve to prevent the gas boiler drum from losing water.
Thirdly, close the deaerator air supply valve, the main power switch and the natural gas valve. The air inlet of the gas-fired boiler burner should not be blocked to reduce the area of the air inlet, and the room ventilation should not be blocked to avoid the formation of toxic and harmful gases.
Different steam pressures correspond to different steam temperatures.
1. The steam temperature of low-pressure boiler is mostly saturation temperature or not higher than 400℃.
2. The outlet pressure of medium-pressure boiler is 3.8 ~ 5.4 MPa, and the commonly used steam temperature is 450℃.
3. The outlet pressure of sub-high pressure boiler is 5.4 ~ 9.8 MPa, and the common steam temperature is 540℃.
Manually close the fuel supply valve, stop the combustion, purge after the program enters, until the end of the purge, stop the program such as burning heavy oil, and enter the line sweeping stage before stopping the combustion, and purge with steam or light oil pipe; Generally, steam purging is used when stopping for a long time.
Generally, it is required that the water temperature shall be reduced to 80℃ to drain the water in the boiler. This is because if the water temperature is high, the temperature in the furnace is still very high, and the metal of the furnace wall and heating surface will still accumulate some heat. After the water is released, there is no working medium in the water wall to cool, which makes the wall temperature rise and the temperature rise is uneven, which is not conducive to the safety of the water wall.
The flue gas treatment of biomass boiler adopts the pretreatment and deep processing. The deep processing adopts the pulsed jet cloth filter, the waste gas treated by this system can meet the discharge standard stably. The flue gas enters the cyclone dust collector or flame arrestor through the dust removal pipeline.
When the water level is high, the quality of steam will drop. This is because the water level will enter the steam-water separator, and the water will slide out with the steam.
It is necessary to confirm whether the boiler pressure is correspondingly higher when steam is not used and lower when steam is used. This is mainly due to the different water pressure and volume under different pressures.
The limited space refers to a space which is closed or partially closed, relatively isolated from the outside world, with narrow entrances and exits, staff can't work in it for a long time, natural ventilation is poor, and toxic, harmful, inflammable and explosive substances or oxygen content is easy to accumulate. To define a limited space, it is necessary to meet the following three conditions at the same time, which are indispensable: the volume is large enough for people to enter completely; Or restrict the entry and exit; It's not designed to stay for a long time.
