Boilers can be safe, economical, reliable. Stable operation, as well as the output of qualified steam or hot water, familiar with the boiler water, understand the dangers of low water quality on the boiler, master the water and steam quality standards, right boiler water treatment, and the necessary chemical treatment in the furnace, and in operation in strict accordance with the standard requirements for supervision of water and steam quality, to ensure that the boiler water quality and steam quality and boiler safety and economical operation is paramount.The purpose of boiler water treatment is to remove impurities that are harmful to the boiler, prevent boiler scaling and corrosion, ensure good steam quality, ensure the boiler's safe and economical operation while achieving the purpose of energy-saving and energy conservation.
Boiler water treatment mainly includes scaling water treatment, make-up water (supplemental boiler water) treatment, condensate (turbine condensate or process recovery of condensate) treatment, feed water de-oxygenation, feed water ammonia, and pot dosing treatment in five parts.
Due to the steam use (heating or power generation) and the degree of condensate recovery, the amount of make-up water in the boiler varies. Condensing power plant boilers are generally less than 3% of the make-up water's evaporation; heating boilers can be up to 100% of the make-up water. Feedwater treatment process: 1. pretreatment 2. softening 3. desalination.
Condensate in circulation will be subject to the turbine condenser cooling of water leakage and system corrosion products caused by pollution and sometimes need to be treated. The amount of condensate treatment is related to the boiler parameters, furnace type (such as with or without a pot or separator), and condensate pollution wishes. As the boiler parameters improve, condensate treatment generally increases gradually. Supercritical pressure boilers should be fully processed; ultra-high-pressure and subcritical pressure boilers for 25% to 100% of the treatment amount; boilers below high pressure with a pot generally do not deal. Commonly used condensate treatment types of equipment are cellulose-covered filters and electromagnetic filters. Condensate in which the removal of corrosion products (copper oxide and iron oxide, etc.), and then into the mixed bed or powder resin-covered filter for deep desalination.
Dissolved oxygen in the boiler feedwater can corrode the thermal system's metals. Corrosion products in the boiler heat load at higher copper and iron scales, so heat transfer deteriorates or even causes a burst tube or deposition in the high-pressure turbine cylinder to reduce the turbine efficiency. Therefore, after softening or desalination of the feed water and condensate, before entering the boiler is generally de-oxygenated. Commonly used oxygen removal methods are thermal oxygen removal and vacuum oxygen removal, and sometimes supplemented by chemical oxygen removal.
After the make-up water treatment, condensate treatment, and feed water de-oxygenation of the boiler feedwater generally require ammonia or organic amines to improve the feed water's pH and prevent corrosion of acidic water on metal parts. Boilers with pot barrels usually are needed to be treated in the pot. When processing, trisodium phosphate or other chemicals are added to the pot barrel to turn the salt impurities in the water that can form scale into sludge that can be discharged in the discharge to prevent or slow down the formation of scale.
Boiler operation, to prevent the generation of scale and its adhesion, to ensure the safe and economic operation of boiler equipment, need to strengthen the boiler water treatment, to ensure that the boiler feed water in line with the feed water quality standards; support the management of pot treatment, to ensure that the pot water quality in line with the pot water quality standards; strengthen the boiler operation management, to ensure that the boiler is running without scale, without deposits. Good drainage, timely exclusion of water slag.
Metal components are broken, coal conservator, water belt wall, convection tube bundle, pot barrel, and other members caused by low water quality and corrosion. Boiler corrosion includes protecting operating boiler corrosion and decommissioning period for boilers with deaerating devices, the primary supervision of the deaerating device deaerating effect.