What is the primary function of a cooling tower in a power plant?

The primary function of a cooling tower in a power plant is to cool down the steam after it has passed through the turbines. After the steam drives the turbines to generate electricity, it needs to be condensed back into water so that it can be reused in the boiler to continue the cycle of generating power. The cooling tower allows the steam to lose heat to the atmosphere, typically by using ambient air to cool the steam, which in turn condenses it back into liquid water. This process is essential for maintaining an efficient closed-loop system, as it ensures that the water used in the process can be recycled continuously, improving the overall thermal efficiency of the power generation process.

In the context of the other options, while water supply, combustion efficiency, and filtration are important aspects of power plant operation, they do not directly describe the primary function of the cooling tower. The cooling tower specifically addresses the need to manage the heat associated with steam generation, which is crucial for the effective functioning of turbines and the overall power plant cycle.