In many technical processes, unused process heat is created. Typical examples: data centers, power plants, energy transformation plants, air-conditioning and refrigeration equipment, other process engineering equipment.
The process heat must be dissipated to protect people, plants, and products from this undesired heat energy. Evaporation cooling plants perform this function. They are also known as industrial cooling towers. Here, one distinguishes between evaporation cooling plants with open/closed circuits or cooling plants with adiabatic pre-cooling. The most common excipient in open evaporation cooling towers is water. Due to its high specific warming capability of about 4187 J/(kg*K), it can take in and save a lot of warming energy during evaporation. This will then be put to use in the evaporation cooling tower. Example: to evaporate 1 kg of water, about 2.3 MJ of energy (evaporation enthalpy) is required.
Other than the ideal quality for this purpose, water also means "life." As the perfect solvent, water can contain salts and solids which it also takes in very easily. If water evaporates then these materials remain in the residual water – this is referred to as thickening. In addition, water is also a breeding ground for the development of biology (algal formation, green color). Aside from the energetically-correct design of the cooling tower to support its cooling capacity, the thickening and the sanitary condition of the water has to be taken into consideration.