The boiler is an energy conversion device, a high-value fixed asset, and the heart of industry. After the heating is over, it is very important to shut down and protect the boiler equipment. Statistical results show that the corrosion during the shutdown of boiler equipment is more serious than the corrosion during operation. Most of the anti-corrosion perforations of boiler equipment do not occur during operation, but during the shutdown period. It is of great significance to take appropriate protective measures to ensure safety and extend the service life of the boiler.
The common methods of boiler shutdown maintenance are usually divided into wet maintenance, dry maintenance and inflation maintenance
Wet maintenance: After the boiler is shut down, the oxygen and air pollutants in the air are discharged and filled with water vapor containing oxidants and corrosion inhibitors. This method can ensure that the inside of the boiler is not affected by erosion and chemical corrosion, and is suitable for boilers made of various materials. At the same time, wet maintenance can also prevent the occurrence of problems such as scaling, scaling, soft scale and green scale.
Dry maintenance: It is to heat the inside of the boiler to a high temperature and exhaust the gas to make the inside of the boiler reach a dry and oxygen-free state to prevent the internal corrosion of the boiler. Dry maintenance is suitable for high-temperature and high-pressure boilers, such as supercritical boilers and turbine boilers.
Pressure maintenance: It is generally suitable for boilers that have been shut down for no more than one week. The residual pressure in the boiler is maintained at 0.5MPa-0.1MPa, and the boiler water temperature is slightly higher than 100℃. Even if there is no oxygen in the boiler water, it can prevent air from entering the boiler drum. In order to maintain the temperature of the boiler water, a small fire can be regularly lit in the furnace, or the steam from the adjacent boiler can be used to heat the boiler water regularly.
