The central air conditioning water system is divided into cooling water system and chilled water system, in which the cooling water system is mainly cooled by cooling tower. The water in the cooling tower splash into numerous small droplets or on the surface of the packing film flow, full contact with air, the air in the dust, microorganism, soluble salts and corrosive gases into the cooling water, the impurity concentration in water increased; in addition due to water evaporation and leakage, constantly flying, also make the impurities the concentration of water increased, which will give the central air conditioning system brings a lot of harm.
The chilled water system is easy to cause the coil blockage due to the corrosive nature. The corrosion of the unit and the pipe accessories will affect the normal operation of the system. At present, the after-sale service of manufacturers generally focus on the maintenance of machinery failure, not including cleaning, maintenance and water treatment, thus leading to a large number of equipment running with dirt. Although some cleaning companies are involved in this industry, the cleaning method still stays in the inorganic acid cleaning stage. This method is toxic to the human body, the pollution of the environment, have a strong corrosion of base metal, often caused by perforation of condenser copper pipe corrosion, serious consequences unit scrapped, so in real time are crucial for the cleaning and maintenance of central air conditioning water system.
I. suggestions for cleaning and maintenance of central air conditioning water system
1, before the air-conditioning operation, the water system should be cleaned to remove the welding slag, oil pollution and so on during the installation process. It is worth noting that: when cleaning the refrigerant water system dry pipe, you should first turn off the cold source unit evaporator, air box and fan coil inlet valve, open the bypass valve, so that the sewage through the bypass valve out of the pipe. The cleaning of the evaporator, wind box and fan coil unit shall be carried out separately.
2, in the process of operation, monitoring every one to two weeks in response to the water, adjust pH within the specified range (6~8), the cooling water concentration control in 2.5~3.5, at the same time, should be timely and replenishment of sewage system.
3, reasonable water treatment, according to the water quality, add corrosion inhibitors, dispersants and biocide, in order to reduce corrosion, prevent scale formation and algae, bacteria reproduction. Zinc chromate and zinc polyphosphate are used as corrosion inhibitors; polyphosphate and polyacrylic acid are used as scale inhibitors; chlorine and hypochlorite can be used as bactericide.
4 、 regularly clean the sediment and debris in the filter and dirt remover on the circuit.
5, after stopping the cooling water for all let go, chilled water, if the water quality if you meet the requirements, can not let go, but if in the winter shutdown, to prevent cracking pipes, for all systems in the water off. After draining the water, clean the dirt remover and filter screen thoroughly.
Another study shows that the cooling tower inlet and outlet temperature is reduced to 20 to 30 DEG C, the cooling water flow rate control system in the range of 1.8 ~ 2.5m/s, which can control the speed of the fungus, calcium and magnesium ions and water is not easy to coalesce into scale, which is one of the central air conditioning water cleaning and maintenance of the system to avoid the key.
Two, central air conditioning water system cleaning steps
1, sterilization, algae: by adding fungicides to the circulatory system, remove all kinds of bacteria and algae in the recycled water.
2, sticky mud stripping: add stripping agent, the pipe will be biological slime stripping off, and through the cycle will be sticky mud cleaning out.
3 、 chemical cleaning: adding chemical cleaning agent, dispersing agent, cleaning the rust, dirt and oil in the pipeline system, dispersing and discharging it into the clean metal surface.
4, surface pre film: into the pre filming agent, in the metal surface forming a dense polymer polymer protective film, in order to prevent corrosion.
5, daily maintenance: addition of corrosion inhibitor, avoid rust, while adding inhibitor, through the comprehensive function, prevent crystallization of calcium and magnesium ions, and regular testing, water quality monitoring.