<p>A design has been developed for a hybrid-type cooling tower with a finned tubulat heat exchanger and corrugated plates installed at an angle of 45°. A mathematical description is suggested for the process of cooling process water in a finned tubular heat exchanger of a hybrid-type cooling tower using the method of the number of heat transfer units. Calculations have been carried out to determine the thermal performance of a hybrid-type cooling tower in the case of variation in the mass flow rates of process water and wetting (cooling) liquid. Data have been obtained on the variation of heat power, heat transfer efficiency, and water temperature at the outlet of a tubular heat exchanger with cross tube finning at various process water flow regimes. It has been established that the highest heat transfer efficiency is achieved at a mass flow of process water of 0.01353 kg/s. It has been found that at a mass flow of water in a tubular heat exchanger of over 0.025 kg/s, there occurs equalization of thermal resistances of heat transfer, which results in a rise of the effect exerted by the wetting liquid mass flow rate on the heat power of a hybrid-type cooling tower. At the highest wetting liquid mass flow rate under investigation, the heat transfer efficiency was 89.3%, and the cooling of process water results in a temperature drop of 8.75°C.</p>