Why is a circulation water concentration factor of 4-5 times designed?

Benefits of increasing the concentration ratio of cooling water: · Increasing the concentration ratio of cooling water allows for a reduction in the amount of make-up water needed, thus saving water resources； · Increasing the concentration ratio of the cooling water can reduce the amount of wastewater discharged, thereby minimizing environmental pollution and the volume of wastewater that needs to be treated ； · Increasing the concentration ratio of cooling water can reduce the consumption of water treatment chemicals, thereby lowering the costs associated with cooling water treatment ； Disadvantages of excessively increasing the concentration ratio of cooling water: · Excessively raising the concentration ratio of cooling water leads to too high levels of hardness and alkalinity in the water, increasing its tendency to form scale ； Therefore, to ensure the effectiveness of cooling water treatment, it is necessary to control the concentration ratio of the cooling water well; generally, a concentration ratio of 4 to 5 is considered optimal for central air conditioning cooling water.

What was said above is already very good! The design is based on ideal conditions; the concentration factor for each system varies depending on the quality of the water used for replenishment. The circulating water system aims to increase the concentration factor as much as possible, while ensuring that scaling does not occur in the system. For further discussion on the operation of circulating water, feel free to add me on WeChat: Azsyx1314

An excessively high concentration ratio poses a risk of corrosion or scaling in the equipment, while an excessively low concentration ratio results in water waste. . . . . .

One more question: By what method is this multiplier for the concentration ratio determined or obtained?

During the operation of circulating water, calcium and magnesium ions precipitate to form calcium carbonate or magnesium carbonate; therefore, measuring these ions is inaccurate, and only estimates can be provided. The correct one is potassium ions

Thank you for your guidance, master. Are there any other methods besides this one?

Method for detecting the concentration ratio of circulating water. During the normal operation of a circulating water system, the concentration ratio is generally calculated by comparing the concentration or a certain property of a specific component in the circulating water to the concentration or a certain property of a corresponding component in the make-up water. That is: ?K＝C_circ/C_supplementary (1), where C_circ is the concentration of a certain component in the circulating water, and C_supplementary is the concentration of the same component in the supplementary water. However, for the component used to determine the concentration ratio, it is required that it not be affected by other operating conditions such as heating, addition of water treatment agents, sedimentation, or scaling. Therefore, the components commonly used include Cl-, Ca2+, SiO2, K+, and conductivity, among others. 1.1 The Cl- and Ca2+ method: Although the determination of Cl- is relatively simple, as it neither volatilizes nor precipitates during the operation of circulating water, our plant often uses chemicals such as Cl2, NaClO, or chloramine to control microorganisms and sludge in the water; this introduces additional Cl-, resulting in a higher concentration factor when using this method for measurement ； At the same time, the circulating water system will accumulate scale to some extent during operation, especially at high concentration ratios, which is why the concentration ratio measured by the Ca2+ method tends to be lower. 1.2 Conductivity method: The determination of conductivity is relatively simple, fast, and accurate. Theoretically, water treatment agents need to be added and Cl2 needs to be introduced into closed-loop water systems, which increases the conductivity of the water. Additionally, leaks in the system equipment can also significantly raise the conductivity; as a result, the conductivity measured by this method will exhibit large errors. In fact, our factory conducted tests using the conductivity method from March to July 1996, and the results showed that the conductivity of the make-up water used as a benchmark—the Yangtze River water—was unstable, with fluctuations ranging from 154 to 291 μS/cm ； The conductivity of the circulating water also fluctuates irregularly; the fluctuation ranges for the first and third circulation cycles are 330–613 μS/cm and 308–618 μS/cm, respectively. Therefore, when the conductivity of the circulating water is high and that of the make-up water is also high, the resulting K value remains low ； When the conductivity of the circulating water is not high and the conductivity of the make-up water is low, the K value is also high. 1.3 SiO2 method: Since no silicate-based water treatment agents are used in our plant’s circulating water system, this method has been employed ever since. When using this method for testing, the data on the concentration ratio of circulating water showed abnormal fluctuations and severe distortion: when compared with fresh water used indoors in the past as a benchmark, the concentration ratios were generally high, with one cycle reaching as high as 8.5 ； When water added via the device was later used as a benchmark for comparison, the concentration ratio was generally low, and in some cases it was even less than 1. 1.4 The K+ method: Theoretically, there are few sources of K+ in circulating water systems; generally, K+ remains relatively stable over a certain period. However, it can also experience changes at different times due to the influence of external factors such as soil and surface water. K+ has a high solubility and does not precipitate from water during operation; therefore, when using the K+ method to determine the concentration ratio of circulating water, there is relatively less interference.

Unfortunately, we can only control it to 2–3 times