Combined Wet and Air Circuit cooling tower: The cooling liquid circulates through the cooling coil, and the heat of the cooling liquid is dispersed into the outer cooling water film through the coil. At the same time, the air outside the unit enters the wind window from the bottom, and the flow direction of the water outside the coil is opposite, countercurrent heat transfer. When the air temperature is higher than 5℃, the cooling water enters the wet cooling heat exchanger at the lower part after sensible heat precooling by exhaust air outside the dry cooler tube at the lower part of the exhaust fan. The cooling water flows turbulently in the pipe and transfers heat from the spray water to the outer wall through the pipe wall. A little part of the spray water evaporates when heated and most of the heat from the spray water is transferred by sensible heat into the air and then discharged by the fan. The spray water falls to the bottom tank under the action of gravity, and in the process of falling, the air into the tower and reverse heat transfer and cooling. The spray water into the tank is then sent by the spray pump to the spray water distribution pipe system for spraying, and so on. When the air temperature is below 5℃, the spray pump stops, and all the heat goes directly through the air zone. Using the dry and cold operation mode to cool the liquid circulating inside the coil can prevent the water from freezing when it meets the air, resulting in air flow blockage or pipeline freezing and cracking, so that the equipment can maintain a better operating state.