How does the nitrogen in the water cooling tower cool the water?

Water cooling tower is a hybrid heat exchanger. The relatively high temperature cooling water (about 35℃) from the air cooling tower flows down from the top spray, and the relatively low temperature sewage nitrogen (about 27℃-27℃) from the switching heat exchanger) the bottom-up flow, the direct contact between the two, not only heat transfer but also mass transfer, is a relatively complex heat transfer process. On the one hand, because the temperature of water is higher than that of sewage nitrogen, there is heat which is directly transmitted from water to sewage nitrogen to cool it down; on the other hand, due to the relatively dry sewage nitrogen, the relative humidity is only about 30%, therefore, the molecules of water can continuously evaporate and spread into the dirt and nitrogen. However, the evaporation of water needs to absorb the latent heat of vaporization. Taking away the heat from the water makes the temperature of the water lower continuously. This phenomenon is like putting a cup of hot boiled water in the air to cool down. Hot boiled water contacts with the air. On one hand, it transmits heat directly (or through the container wall) to the air, on the other hand, it steams, steam and spread the molecules of water into the air to take away the heat (latent heat of vaporization), making the hot boiled water cool down continuously. It must be pointed out that the moisture absorption of sewage nitrogen is the main factor to cool the water, so the relative humidity of sewage nitrogen is the key to influence the cooling effect. This is also the reason why the outlet temperature of cooling water may be lower than the inlet temperature of sewage nitrogen.