In the production processes of many industrial sectors, a large amount of waste heat is generated, which needs to be promptly transferred to the natural environment using heat transfer media to ensure the normal operation of the production process. Due to its excellent heat transfer performance, low cost, and abundant resources, natural water is used as a heat transfer medium for industrial waste heat, known as cooling water in industrial production. Industrial cooling water is the largest user of industrial water in various countries, and its physical and chemical properties do not change significantly except for raising the temperature. If appropriate cooling measures are taken to form a recycling system, it is an important way to save industrial water.

Domestic situation

(1) The efficiency of reusing circulating cooling water is very low. In the general chemical industry in China, the concentration ratio of circulating water is about 2-3 times, while in the petrochemical industry it is about 4 times. The concentration factor of circulating water in developed countries is about 5 times, while in China, the concentration factor of circulating water is lower compared to developed countries. The low concentration factor of circulating water means that the discharge volume of circulating water is large, the amount of supplementary water is large, and the water cost required for the circulating system is high.

(2) The energy consumption of the circulating cooling water system is too high. At present, there are many shortcomings in the operation of circulating cooling water systems in the chemical industry, mainly including: in China, circulating cooling water systems have not received sufficient attention, and the operation of the system lacks corresponding theoretical support. Therefore, parameters such as circulating water volume and outlet temperature of circulating water have not been adjusted accordingly in different seasons.

(3) The surplus of fans and circulating water is too large. The water supply and treatment capacity of water pumps, fans, and pipelines have long been subject to the phenomenon of "big horses pulling small cars" compared to actual requirements, resulting in serious waste of energy consumption.

　　The principle of circulating cooling water system

A cooling water system that uses water as a cooling medium and circulates it. It mainly consists of cooling equipment, water pumps, and pipelines. After the cold water flows through the production equipment that needs to be cooled (often referred to as heat exchange equipment, such as heat exchangers, condensers, and reactors), the temperature rises. If it is discharged immediately, the cold water is only used once (called a direct flow cooling water system). If the heated cold water flows through the cooling equipment, the water temperature will drop back. It can be pumped back to the production equipment for reuse, greatly reducing the amount of cold water used and often saving more than 95%. Cooling water accounts for about 70% of industrial water consumption, therefore, the circulating cooling water system plays a role in saving a large amount of industrial water.