Blast furnace (BF) slag flushing water is high-temperature wastewater (60–90℃) generated during the steel smelting process, with extremely high recycling value. For a long time, the waste heat from slag flushing water has been mainly used for central heating in northern China, while its recycling rate in southern China is generally low. This not only causes energy waste but also becomes a prominent pain point restricting the green and low-carbon development of the industry.

Based on the actual energy demand of customers, Guoshun Group has innovatively designed a three-in-one slag water waste heat heating system integrating "direct heat exchange + heat storage + intelligent regulation". The system adopts high-efficiency direct heat exchange technology to extract clean thermal energy from BF slag flushing water and transports the clean thermal energy to greenhouses through pipe networks, realizing uniform and automatic regulation of the temperature inside the greenhouses.

After the project is put into operation, the temperature inside the greenhouses can be increased by up to 15℃ as needed, which meets the temperature requirements of crops at different growth stages, realizes off-season planting, and seizes the high-price market window. The project can recover about 35,000 gigajoules of waste heat annually, equivalent to more than 1,200 tons of standard coal, reduce carbon dioxide emissions by over 3,000 tons, and lower the winter heating cost of greenhouses by more than 40%, forming a closed-loop economic model of "industrial energy supply - agricultural value-added - ecological carbon reduction".