Take an automobile manufacturing plant for example, during the period from April to November, the car body cleaning consumes steams 2m3/h for 23 hours a day; and the water temperature is 65℃. The plant consumes cooling water 1,000m3/h for car body welding, and the water temperature is 28℃; and consumes cooling water 500 m3/h for the cooling of air compressor, the temperature of the cooling water is 21℃ in winter and 37℃ in summer. Thus we can see that the plant generates a great deal of heat and cannot take use of it reasonably, which causes waste of the energy and environment pollution.

After energy-saving retrofitting, the industrial waste heat recovery system recovers the heat released during the cooling process and generates 65℃ hot water for the heating of the workshop and the cleaning of car body, which reduces the consumption of steams. By using the industrial waste heat recovery system, the plant can save steam cost 2.51 million Yuan a year, and the payback period is only 7 months. Meanwhile, the system can save coal 1,182 tons, reduce CO2 emission 8,504 tons, SO2 28 tons, and NOx 24 tons a year, which realizes reasonable usage of energies and promotes the development of circular economy.