Overview of Ultra Pure Water Supply System for Power Boiler 　　Coal fired power plants are an important component of China's power industry. The use of water in the power industry is multifaceted, mainly including boiler makeup water, cooling water, and miscellaneous water for domestic firefighting. The most stringent requirement for water quality is boiler feedwater. Nowadays, thermal power plants are developing towards large capacity and high parameters, and the water quality of boiler feedwater is also increasing. The requirements for boiler feedwater water quality are very strict. Therefore, in addition to conventional water treatment methods such as coagulation, sedimentation, and filtration, pure water preparation technologies such as ion exchange, reverse osmosis, electrodialysis, softening, and desalination are also needed.

Requirements for water supply to power boilers

Device ion exchange electrodialysis Reverse osmosis Roll film cellulose acetate hollow fiber membrane Polyamide pigment Turbidity/degree Reverse flow regeneration<2 Downstream regeneration<5 ＜ 2 ＜ 0.5 ＜ 0.3 COD/mg . L － 1 ＜ 2.3 ＜ 3 ＜ 1.5 ＜ 1.5 Free chlorine/mg · L-1 ＜ 0.1 ＜ 0.1 0.2 ～ 1.0 0 Total iron/mg. L-1 ＜ 0.3 ＜ 0.3 ＜ 0.05 ＜ 0.05 铝 /mg . L － 1 — — ＜ 0.05 ＜ 0.05 Surfactant/mg. L-1 ＜ 0.5 — Cannot detect Cannot detect Oil content, H2S, etc — — Cannot detect Cannot detect

Process flow for preparing ultrapure water for power boiler feedwater system 　　The process of preparing super water in the power industry can be roughly divided into the following categories:
　　 1The process of using ion exchange is as follows:
Raw water → raw water booster pump → multi-media filter → activated carbon filter → water softener → precision filter → cation resin filter bed → anion resin filter bed → anion resin mixed bed → microporous filter → water point
　　 2Adopting a two-stage reverse osmosis method, the process is as follows:
Raw water → Raw water booster pump → Multi medium filter → Activated carbon filter → Softener → Precision filter → First stage reverse osmosis → PH adjustment → Intermediate water tank → Second stage reverse osmosis (with positive charge on the surface of the reverse osmosis membrane) → Purified water tank → Pure water pump → Microporous filter → Water point
　　 3The process of using EDI is as follows:
Raw water → Raw water booster pump → Multi medium filter → Activated carbon filter → Softener → Precision filter → Primary reverse osmosis machine → Intermediate water tank → Intermediate water pump → EDI system → Microporous filter → Water point

Characteristics of the ultra pure water equipment for the power boiler feedwater system produced by our company
The traditional preparation process of ultrapure water usually uses ion exchange resin for production, but the use of ion exchange resin usually requires frequent resin regeneration, which consumes both material resources and labor. After years of practice and combined with the latest membrane separation technology, our company often uses a combination of reverse osmosis and ion exchange system (or EDI) to prepare ultrapure water. Compared with traditional processes, this process has the advantage of low operating costs (the regeneration cycle of ion exchangers is greatly extended) and reliable operation. Compared with the latest technology, it has the advantages of low cost and easy availability of consumables. The reverse osmosis process technology is advanced and reliable.

three typesthree kindsthree varieties

　　 preparation
　　Process Comparison of Ultra Pure Water for Power Boiler Feedwater SystemAt present, the processes for preparing ultrapure water for the chemical industry are basically the above three types, and most of the other process flows are derived from different combinations and combinations based on the above three basic process flows. Their advantages and disadvantages are listed below:
　　 1The first method of using ion exchange resin has the advantages of low initial investment and less space occupation, but the disadvantage is that it requires frequent ion regeneration, consumes a large amount of acid and alkali, and has a certain degree of environmental damage.
　　2The second method uses a two-stage reverse osmosis equipment, which is characterized by a higher initial injection rate than using ion exchange resin, but does not require resin regeneration. Its disadvantage is that the relevant membrane components need to be cleaned or replaced regularly, and the water quality is relatively low, mostly only around 1 US/cm.