The counterflow closed-loop cooling tower operates on the principle of an internal recirculating water system: The circulating water is heated by heat exchange with a heat source and then enters the heat exchanger. Heat is transferred through the heat exchanger tubes to the outside environment. The cooled circulating water is then pumped back to the heat source by the system's circulating pump.

The external recirculating water system: The spray water is transported from the lower water trough to the upper distribution pipeline by the sprinkler pump. After being sprayed out, it comes into contact with the heat exchanger tubes, and some of the water evaporates, carrying away heat. The cooled spray water then falls back into the lower water trough for recirculation. The internal recirculating water undergoes heat exchange through the heat exchanger tubes (coiled pipes), thus preventing direct contact with the external recirculating water and air, which avoids water quality contamination.