Closed cooling tower heat exchanger coil adopts rustproof aluminum alloy seamless aluminum tube bending and forming at one time, after 20kg airtightness test. The fan adopts cooling special moisture and heat resistant fan blade and motor. The cooling water pump adopts the industry's high quality low head and high flow rate water pump. The shell and supporting parts are made of Baosteel aluminum-plated zinc plate, which is highly corrosion-resistant.