Air conditioning water system cleaning is a process of various physical, chemical and biological treatment of water in the air conditioning system to ensure that the water quality is pure, free of impurities and microorganisms, which can protect equipment, improve system efficiency, save energy, ensure indoor air quality, and at the same time reduce accidents, improve refrigeration effect, save a lot of maintenance costs, and maintain the normal operation and efficient operation of the system.
1. Common types of chemicals in air conditioning water systems
Common types of water treatment chemicals:
corrosion inhibitors; antiscalants;
pre-filmants; descalers;
Bactericidal algaecide.
corrosion inhibitors; It is a chemical additive that can slow or stop the rate of corrosion of metals in a specific medium. Its mechanism of action is to form a protective film on the metal surface, which can be a chemisorption film, an oxide film or a precipitation film, which can prevent the direct contact between the corrosive medium and the metal surface, thereby reducing the corrosion rate of the metal.
antiscalants; It is a chemical specifically designed to prevent or slow the fouling of insoluble inorganic salts in water systems. Antiscalants play a key role in air conditioning systems, and can alter the crystallization process of scale, making it unstable or difficult to form a continuous scale layer. This prevents these ions from precipitating on the surface of the metal to form a scale layer.
pre-filmants; It is a chemical specifically designed to form a protective film on the metal surface of an aqueous system. The main function of this protective film is to prevent the metal surface from direct contact with the corrosive medium in the water, so as to slow down or prevent the occurrence of the corrosion process, so as to ensure the corrosion resistance of the metal equipment during long-term operation.
descalers; Chemicals used to remove the scale layer that has formed in the water system or to prevent the formation of the scale layer. Its working principle is mainly achieved through chelation, complexation and adsorption dispersion. It can effectively remove the scale layer in the water system, restore the normal operation of the system and the performance of the equipment.
Bactericidal stripping agent.
Also known as slime stripper, it is composed of fungicide, surfactant, strong penetrant, stabilizer, etc., which can quickly penetrate into the slime colloid, oxidize and decompose to release bubbles, combined with the role of fungicide and active agent, so that the slime is discharged with the water flow after falling off, so as to achieve the purpose of strong peeling and cleaning, so that the surface is clean, so as to prevent corrosion under the scale.
2. **Air conditioning water treatment and cleaning operation
Cleaning of cooling water systems
It is mainly aimed at deposits such as scale, biological slime, corrosion products and other deposits on the inner wall of cooling towers, cooling water pipes, and condensation heat exchange surfaces.
1. Check the equipment of the cooling tower, cut off the power supply of the cooling tower, manually clean the tower body, floor, packing, etc., and rinse it with a high-pressure water gun repeatedly. A special bactericidal algaecide is added to the tower, and the pump is turned on for 16-24 hours for the whole system sterilization and algaecide treatment.
2. Add cleaning descaling agent in the tower, open the pump for 16-24 hours, the agent can penetrate and wet to the inside of the dirt, so that the greasy dirt is easy to fall off, and the dirt, scale, rust, mud, etc. are taken away with the flowing water to achieve the purpose of cleaning.
3. Drain the cooling water, clean the cooling tower, disassemble the Y-shaped filter in the cooling system room, clean the debris in the filter screen and add clean cooling water. A pre-coating agent is added to the cooling tower and the system is cleaned in the first two steps to prevent corrosion of the metal surface. Control pH at 55-6.5. Discharge after 24 hours of operation.
Cleaning of chilled water systems
It is mainly aimed at the sediments such as biological slime and corrosion products on the surface of the evaporator heat exchange, the inner wall of the chilled water pipe, the inner wall of the fan coil unit and the air conditioning system equipment.
1. The external water pump is added with bactericidal algae agent from the sewage outlet, and the pump is opened for 16-24 hours to remove the domestic sludge for the whole system. The external water pump adds cleaning agent from the sewage outlet, and the pump is opened for 24 hours to penetrate and peel off the floating rust and oil in the system.
2. Discharge the chilled water, and discharge the cleaned rust slag and sludge out of the refrigeration system. Disassemble the main pipe filter in the refrigeration system room, remove the debris on the filter screen, seal the filter, and fill and exhaust the system until the chilled water is full. Turn on the refrigeration pump for half to 1 hour, stop the pump to drain the whole system, drain it and then inject it, and then rinse it repeatedly until the water is clear and transparent.
3. The external water pump adds pre-film liquid from the sewage outlet, and after the system is cleaned, its metal surface is in a very active state, which is easy to be secondary oxidized, so the system should be pre-filmed to prevent the metal table from being corroded. Add pre-filmant and control the pH at 55—6.5. Put after 24 hours of operation.
4. Discharge 2 3 chilled water, add corrosion inhibitor from the sewage outlet with an external water pump, and open the pump for 2 hours to make the drug evenly distributed in the system. Test the pH value, and the normal pH value is 8 -10 to do the dip test.
5. Clean the coil fins, remove the coil to fix it, blow the fins with air pump compressed air, spray the dust cleaning agent on the fins with a watering can, and finally rinse it with clean water.
6. Clean the fan blades: take the fan out of the box, separate the fan motor, and clean the fan and impeller.