What can the circulating water concentration ratio indicate?

In an open-loop cooling water system, heat is transferred to the atmosphere primarily through the evaporation of water, thereby reducing the temperature of the cooling water. The water that evaporates in this process is theoretically pure water, free of various impurities and ions. After some of the circulating water in the system evaporates, the amount of water remaining in the system decreases, and it becomes necessary to replenish water at this point. We use tap water as the supplementary water in most cases, and tap water contains a large amount of impurities and various ions. As the system continuously evaporates pure water free of impurities, it simultaneously replenishes itself with tap water that contains impurities. Therefore, the concentrations of various ions in the circulating water within the system will become increasingly high. To this end, we introduced a concept known as the concentration factor to express the degree of water concentration in this system. 　　Concentration Ratio (COC) = a certain parameter of the water quality in the system / the same parameter of the water added to the system. For example, if the total hardness of the water in the system is 1000 ppm, while the total hardness of the water added is 100 ppm, then COC = 1000/100 = 10 times. 　　One of the parameters in this formula can typically be chosen as total hardness, conductivity, chloride ions, or potassium ions, among others. 　　What’s the point of knowing the concentration factor? 　　We can understand it this way: if the concentration ratio of the system is 1, it means that the water quality in the system is the same as that of the water added to it, which implies that almost all of the water added is discharged. 　　If the concentration factor is 2, it means that the water discharged is equivalent to 1/2 of the water added ； 　　If the concentration factor is 5, it means that the water discharged is equivalent to 1/5 of the water added ； 　　If the concentration factor is 8, it means that the water discharged is equivalent to 1/8 of the water added. 　　Now you understand its meaning. Simply put, the higher the concentration ratio, the greater the efficiency of water resource utilization.

The typical concentration ratio in plants is the ratio of chloride ions in the circulating water to those in the make-up water

If the amount of water evaporated is ignored, the concentration factor can be simply understood as the ratio of water added back to the water removed as wastewater. The higher the concentration, the less wastewater is produced, resulting in greater water savings.