Chilled water is circulating water that is cooled by a refrigerator and then flows to a cooling process. It is mainly used in central air conditioners and systems that require low-temperature cooling. In terms of the structure of the cooling system, the chilled water is of a closed type and a non-closed type, and the non-closed type is divided into a partial open type and a spray type. The central air-conditioning chilled water system is mostly closed; the chilled water system in the factory is mostly open; the chilled water system with sprinkler is mainly found in places where air washing and air humidity control are required, such as textile mills and electronic components manufacturing. Workshop, etc. The temperature of the water after cooling the chilled water is very suitable for the growth of the algae. The growing algae will form a biological slime, and a large number of bacteria such as anoxic bacteria, iron bacteria, nitrifying bacteria, and sulfate reducing bacteria will be produced in the pipeline, resulting in a pipeline. The corrosion of the inner wall causes the rust peel to fall off, which affects the heat exchange of the condenser; the circulation cooling water also grows bacteria such as Legionella to cause damage to the human body. The calcium and magnesium ions in the circulating water will form scale with the increase of the water temperature during the heat exchange of the condenser, and adhere to the inner wall of the copper tube of the condenser to form dense scale (mainly calcium carbonate scale). Scale and dirt often combine, and scaling and slime can cause or aggravate corrosion, seriously affecting heat transfer. Therefore, the main task of cooling circulating water treatment is to eliminate or reduce the damage of scaling, corrosion and biological slime. Compared with cooling water, it has the following characteristics: In general, the amount of water stored and the amount of circulating water are smaller. The water temperature is relatively low, generally varying between 1 ° C and 20 ° C, mostly between 6 ° C and 12 ° C. The concentration factor remains essentially the same. In the closed chilled water system, there is basically no loss of water during the circulation because there is no contact with air and no evaporation. Part of the open chilled water system is only exposed to the open part of the cold water pool, and the amount of exchange with the air is small, negligible, so there is almost no water loss during the cycle. The chilled water system with sprinkler system has a special hygroscopic phenomenon during the circulation in summer, that is, there is no loss of water during the cycle, but the ion concentration in the system is lower than the supplementary water due to the water vapor entering the system. Since this ion concentration change is small, it can be considered that the concentration factor remains substantially unchanged. In the winter, due to the humidification of the air, the chilled water has a certain concentration. The water treatment agent is a one-time input, and in order to ensure the effectiveness of the medicine, the medicine is discharged in a specific cycle. The hazard of chilled water to equipment is mainly corrosion, and red water often occurs due to corrosion. Ferrous hydroxide is easily oxidized into reddish brown rust, which is the main cause of red water in chilled water. In open and spray systems, dissolved oxygen is more abundant in the system due to partial exposure of the system to air or direct contact with air. In closed chilled water systems, dissolved oxygen is rapidly consumed by corrosion. It is not enough. Water treatment agent classification Corrosion inhibitors can be classified into inorganic corrosion inhibitors, organic corrosion inhibitors, and polymer corrosion inhibitors. Inorganic corrosion inhibitors mainly include chromates, nitrites, silicates, molybdates, tungstates, polyphosphates, zinc salts and the like. The organic corrosion inhibitor mainly includes a heterocyclic compound containing a nitrogen oxide compound such as a phosphonic acid (salt), a phosphonic acid, a mercaptobenzothiazole, a benzotriazole, a sulfonated lignin. Polymer corrosion inhibitors mainly include polymer chemicals of some oligomers such as polyethylene, POCA, and polyaspartic acid. Inhibitor It refers to a class of agents which have the ability to disperse insoluble inorganic salts in water, prevent or interfere with the precipitation and scaling of poorly soluble inorganic salts on metal surfaces, and maintain good heat transfer in metal equipment. The cold-exchange equipment anti-corrosion and scale inhibitor is prepared from epoxy resin and specific amino resin, and is prepared by adding various kinds of various anti-rust, anti-corrosion and other additives. It has excellent shielding, impermeability, rust resistance, good scale inhibition, thermal conductivity, excellent resistance to weak acid, alkali, organic solvent, etc. It has strong adhesion and the film is bright, flexible, dense and hard. .